Biomedical subjects

M Tamura

Publications and source records attributed to M Tamura.

At least 685 records · Page 38Linked to original sources

PubMed1990

Ventricular tachycardia with two possible exits from one re-entrant circuit.

A case of sustained ventricular tachycardia (VT) with two possible exits from one re-entrant circuit is described in this paper. The patient was a 27-year-old female who had undergone corrective surgery for tetralogy of Fallot at the age of 8, and developed VT of distinctly different QRS configurations. The exit of one VT was at the right ventricular (RV) outflow tract and the other at the RV apex as determined by endocardial and pace-mapping. Continuous and split activities were observed at the RV outflow tract during both types of VT. One VT was entrained by rapid pacings, and the causal mechanism was thought to be re-entry and common re-entrant circuit was established for two QRS configurations of VTs. A discrepancy was observed between the site of the earliest activation and the site of the pace-mapping which resulted in QRS configuration of VT of the RV apex origin. The findings in this paper should be considered when contemplating aggressive therapy such as electrical ablation.

Adult↗

PubMed1990

[Pharmacological studies of celiprolol: I. Beta-blocking effect, intrinsic sympathomimetic activity, vasodilating and hypotensive effects].

The beta-blocking effect, intrinsic sympathomimetic activity (ISA), and vasodilating and hypotensive effects of celiprolol were tested. 1. Celiprolol competitively antagonized the isoproterenol-induced positive chronotropic and inotropic effects in guinea pig right atrial and papillary muscles and isoproterenol-induced guinea pig tracheal relaxation with pA2 values of 8.03, 7.98 and 6.43, respectively. 2. In dogs, isoproterenol-induced increases in cardiac contractility and heart rate were markedly inhibited by celiprolol (83.1 and 84.8%, respectively), while isoproterenol-induced hypotension was suppressed only by 16.8%. 3. Celiprolol increased the beating rate of the right atrium and relaxed the trachea isolated from normal and reserpinized guinea pigs. Celiprolol also potentiated the contractility of the left atrium isolated from reserpinized animals. These effects of celiprolol were antagonized by propranolol. 4. Celiprolol concentration-dependently relaxed rat femoral arteries contracted by methoxamine. The concentration-relaxation curve was shifted to the right by pretreatment with propranolol. 5. Orally administered celiprolol produced long lasting hypotension in conscious SHR without any heart rate change. 6. These results indicate that celiprolol is a highly cardioselective beta-blocker with a significant ISA, which contributes to its vasodilatory and hypotensive effects.

Adrenergic beta-Antagonists↗

PubMed1990

Enhanced expression of the sis and c-myc oncogenes in human meningiomas.

In 19 human meningiomas (14 primary and four recurrent tumors and one tumor transplanted into athymic nude mice), oncogene expression, amplification, and rearrangement, and loss of heterozygosity on chromosome 22 were examined. Compared to nontumor brain tissue, there was greater than a fivefold expression of the sis oncogene in six (40%) of 15 tumors studied and of the c-myc oncogene in 12 (63%) of the total 19 tumors. Expression of the sis gene was lower in the recurrent tumors than in the primary cases, and there was no detectable expression in anaplastic meningioma cells. Rearrangement of the sis gene was found in one meningioma. Loss of heterozygosity on chromosome 22 was detected in two of the five informative heterozygous cases. Expression of the c-myc gene was higher in cases with a loss of heterozygosity than in those without. These results suggest that the sis and c-myc oncogenes are associated with tumorigenicity and that c-myc may induce meningiomas through loss of the putative tumor suppressor gene.

Adult↗

PubMed1990

Practical debittering using model peptides and related compounds.

In order to develop a practical debittering method for amino acids and peptides, several debittering methods were studied. The authors found that hooking acidic amino acids to and acetylation of bitter amino acids is very effective to remove the bitterness from their concentrated solution. For debittering by mixing with additives, skin milk and other peptide compounds were effective. Acidic amino acids were also effective to reduce the bitterness. Gelatinized starch was found to be useful for debittering because it takes bitter substances into its net structure.

Amino Acid Sequence↗

PubMed1990

Mechanism for the bitter tasting potency of peptides using O-aminoacyl sugars as model compounds.

In order to study the role of hydrophobicity in bitter peptides, several O-aminoacyl sugars, in which amino acids or peptides were attached to the 2- and 3-position of methyl alpha-D-glucopyranoside, were synthesized and sensory analyses were carried out. It was found that the bitterness increased as the hydrophobicity of compounds increased, implying that the bitterness receptor recognizes the hydrophobicity of bitter peptides. A structure for the bitterness receptor is also discussed.

Amino Acid Sequence↗

PubMed1990

Peripheral blood neutrophil function in germfree and conventional rats.

The superoxide anion production and the myeloperoxidase activity between polymorphonuclear cells (PMNs) from conventional and germfree rats were compared. Furthermore, the response to recombinant human granulocyte colony stimulating factor (G-CSF) between both groups of rats was also examined. Our present investigation showed that: (1) the basal superoxide anion production by PMNs in germfree rats (2.1 +/- 0.5 nmol/min/1 x 10(6) PMNs) is less than one fourth of that of conventional rats (9.5 +/- 2.9 nmol/min/1 x 10(6) PMNs). (2) the myeloperoxidase activity of PMNs from germfree rats (38.1 +/- 5.2 nmol/min/1 x 10(6) PMNs) is 1.7 times that of conventional rats (22.4 +/- 4.9 nmol/min/1 x 10(6) PMNs). (3) G-CSF administration increased the number of PMN, 12.4 times in the germfree rats compared with 3.9 times in the conventional rats. (4) the PMNs induced by G-CSF do not differ in the superoxide anion producing activity. However the myeloperoxidase activity decreased in the G-CSF induced PMNs of both groups of rats. From our data, the conventional rats could have a more effective killing activity than the germfree rats. Furthermore, germfree rats may be used as a powerful tool for assay of other biological substances relating to immune system and its regulation.

Animals↗

PubMed1990

Scleroderma renal crisis in progressive systemic sclerosis: a case report.

We report a case of progressive systemic sclerosis with scleroderma renal crisis 10 years after onset. The patient (female) had progressive renal dysfunction, hypertension which was difficult to control, and massive gastrointestinal bleeding. An angiotensin converting enzyme inhibitor (enalapril) could not control her hypertension. Only intravenous nicardipine had a slight effect on her hypertension. Hemodialysis and plasma exchange, did not reverse the renal crisis, and the patient died. Microscopic examination of her kidney showed thickening of the capillary walls and mild nephrosclerosis.

Acute Kidney Injury↗

PubMed1990

[Significance of HDL cholesterol/apolipoprotein A-I ratio].

HDL cholesterol (HDL-Ch)/apolipoprotein A-I (A-I) ratio was studied in fourteen healthy students, fifteen male habitual drinkers, five male patients with chronic hepatitis (CH) and seven controls. HDL-Ch/A-I ratio in male students, female students, male drinkers, CH and control were 0.36 +/- 0.029, 0.39 +/- 0.03, 0.41 +/- 0.065, 0.40 +/- 0.02, and 0.36 +/- 0.039, respectively. Elevation of HDL-Ch/A-I ratio in female students, male drinkers and CH were statistically significant compared with control, while there was no significant change in HDL-Ch or A-I in female students but the elevations of both in male drinkers or the reduction of A-I in CH. Positive correlations were found between HDL-Ch/A-I ratio and HDL2-Ch, and HDL2-Ch/HDL3-Ch ratio in students and CH. The elevation of HDL-Ch/A-I ratio in CH appeared to be related to the reduction of HDL3-Ch. It is suggested that HDL-Ch/A-I ratio could indicate HDL2-Ch/HDL3-Ch ratio and is useful parameter for analysis of HDL metabolism.

Adult↗

PubMed1990

[Abnormal local ventricular electrogram and its relation to induction of ventricular tachycardia in patients with hypertrophic cardiomyopathy].

To investigate the mechanism of induction of ventricular tachycardia (VT) in patients with hypertrophic cardiomyopathy (HCM), we reviewed and analyzed the local ventricular electrograms (LVE) at the pacing sites in 15 patients with HCM and 52 control subjects. Each patient had a clinical history of nonsustained VT or syncope. The results were as follows: 1. Rapid and polymorphic VT was induced in six of the 15 patients with HCM and in 10 of the 52 control subjects. 2. The duration of the LVE at the pacing site was progressively prolonged as the number of extrastimuli were increased or the premature intervals were shortened. Compared with the controls, patients with HCM had longer durations of the LVE by basic drive, single extrastimulus, and by double extrastimuli: 113 +/- 31 vs 95 +/- 16 ms (p less than 0.005), 156 +/- 35 vs 109 +/- 17 ms (p less than 0.001), and 220 +/- 88 vs 133 +/- 25 ms (p less than 0.001), respectively. 3. In the HCM group, the maximum duration of the LVE by double ventricular extrastimuli was significantly longer in patients with inducible VT compared with those with non-inducible VT: 287 +/- 95 vs 183 +/- 56 ms (p less than 0.05). 4. Induction of VT in the HCM group was accompanied by the critical prolongation of the LVE at the pacing site. In two of the six patients with HCM, the LVE at the pacing site spanned the entire cardiac cycle at the time of the initiation of VT.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiomyopathy, Hypertrophic↗

PubMed1990

[IBL like T cell lymphoma associated with hemolytic anemia and polyploidy chromosomal abnormality--a case report].

A 56-year-old man was admitted to Sapporo Kitano Hospital on May 30, 1987 because of fever, retention of ascites and pleural effusion, generalized lymphnode swelling and hepatosplenomegaly. Laboratory findings showed Coombs' positive hemolytic anemia, leukocytosis and polyclonal hypergammaglobulinemia. Serological test included positive RA factor, anti-DNA 16 U/ml, thyroglobulin Ab 1600 x and microsome Ab 3200 x. A cervical lymphnode specimen exhibited typical histologic picture of IBL like T cell lymphoma. The surface markers of lymphoma cells were CD2(+), CD8(+) and CD4(-). Chromosomal analysis of these cells revealed polyploidy abnormality for all chromosomes except for No. 14's which are disomy. All lymphoma cells have XXY sex chromosome and mar1, mar2, mar3. Gene rearrangement for beta-chain of T cell receptor was proved in these lymphoma cells. He was treated with prednisolone, vincristine, cyclophosphamide, adriamycin etc, but died of respiratory failure 171 days after admission. We reported a rare case of IBL like T cell lymphoma with polyploidy chromosomal abnormality accompanied with hemolytic anemia.

Anemia, Hemolytic↗

PubMed1990

[Non-invasive assessment of mitochondrial function in rat brain during and after hemorrhagic shock].

Brain oxygen metabolism was studied noninvasively by the simultaneous measurement of hemoglobin (Hb) oxygenation, and cytochrome oxidase (aa3) redox state in the brain of a rat, using our near-infrared (NIR) transmission spectrophotometer. Redox state of cyt. aa3 was measured using a wavelength pair of 830-940 nm. The changes of oxy- and total (oxy + deoxy) Hb content in the rat brain could be monitored quantitatively by expressions of -1.15 delta A750 + 1.39 delta A780 and -0.29 delta A750 + 0.59 delta A780, respectively (delta A750, delta A780: absorbance changes at wavelength 750 and 780 nm). An application of NIR-Spectrophotometry for the studies of brain metabolism in acute hemorrhagic shock in rats was presented. Tissue hypoxia was induced in 20 rats by rapid withdrawal of arterial blood to a mean blood pressure of 30 mmHg. This level of shock pressure was maintained for 30 minutes in group A (n = 8), and for 70 minutes in group B (n = 10), then the removed blood was returned by infusion. Blood oxygenation level, relative blood volume and cyt. aa3 redox state in the rat brain were monitored during shock, and for two more hours after the reinfusion. Group A had a high survival rate while group B had a poor survival rate. In both groups with the onset of hypotension, there occurred a rapid deoxygenation of brain blood and a rapid and progressive shift of cyt. aa3 towards a more reduced state.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1990

[Cytomegalovirus encephalitis in immunologically normal adults].

We report two cases of cytomegalovirus (CMV) encephalitis in immunologically normal adults. Patient 1, a 53-year-old man: onset was acute with headache and pyrexia, followed by moderate disturbance of consciousness with meningeal signs. Repeated lumbar puncture revealed 58 CSF cells per microliters and 96 mg protein per dl. On the 11th day after onset, we started treatment with adenine arabinoside (ara-A). He recovered completely. With IgG-ELISA methods, antibody to CMV turned into positive on the third week, and into negative again on the fifth week, and these conversions were concomitant with the symptomatic aggravation and amelioration, respectively. Patient 2, a 78-year-old woman: onset was acute with general fatigue and pyrexia, followed by meningeal signs and mild disturbance of consciousness. Consciousness level was worsened and two courses of acyclovir (Acv) treatment were started on the 59th and on the 93rd day after onset, but consciousness level went down to coma and she died. Repeated lumbar puncture revealed 787 CSF cells per microliters and 229 mg protein per dl. CMV antibody titer (CF) in CSF was 1:32 and antibody index was 58 or more, suggesting antibody production in central nervous system. CMV encephalitis in immunologically normal adults is very rare, only 10 cases having been reported so far. Most patients recover spontaneously, but some may be fatal. In our view ara-A treatment should be taken in consideration in case of acute encephalitis unresponsive to Acv.

Aged↗

PubMed1990

[Two cases of benign polyps of the posterior urethra (ectopic prostatic tissue)].

We report two cases of benign polyps of the posterior urethra. Their first symptoms were gross hematuria and urinary frequency. Both specimens obtained by transurethral resection were histologically identified as prostatic tissue. Discussion on benign polyps of the posterior urethra as ectopic prostatic tissue was done with review of literature.

Choristoma↗

PubMed1990

[Problems associated with radical neck dissection in patients with tongue carcinoma: four cases of stage I tongue carcinoma that recurred in the cervical area after the dissection].

Reported are four cases of a stage I tongue carcinoma which recurred in the cervical area after a radical neck dissection (RND). In all cases, the primary lesion was controlled with radium needle implants. Clinically, these tumors manifested endophytic growth and, histologically, had a high malignant grading. In most cases, a latent lymph metastasis appeared within 6 months after initial treatment and an early metastatic lesion developed beyond the capsule of the node. The site of cervical recurrences was located in non treated areas that were outside the range of the RND.

Aged↗

PubMed1990

[Bronchiolitis obliterans organizing pneumonia (BOOP) in Japan].

Twenty-nine patients with bronchiolitis obliterans organizing pneumonia (BOOP) in Japan diagnosed by an open lung biopsy were reviewed. A total of 70% of the patients were idiopathic and 2/3 of the remaining were associated with connective tissue disease. All 29 cases of BOOP showed bilateral pulmonary infiltration on chest X-rays. BOOP can be classified based on the chest X-ray findings into three major types, Type I, Type II and unclasSified type. In Type I shadows appear in the lung fields. In Type II abnormal shadows are seen in the bi-basilar peripheral field with the reduction of the lung volume. Cases of Type I showed inflammatory findings more frequently than cases of Type II. Among 29 BOOP patients, two idiopathic cases died.

Adult↗

PubMed1990

[Clinical study on asbestos pleurisy and review of literature].

Seven asbestos workers with asbestos pleurisy were investigated in terms of clinical symptoms, findings of pleural biopsies and course of chest roentgenograms. All cases were male and smokers. Duration of asbestos exposure ranged from 3 to 33 years (mean: 20.6 years). Duration between initial exposure and onset of the pleurisy ranged from 22 to 34 years (mean: 28.7 years). Five pleural effusions were aseptic and exudative, and one had sanguineus and eosinophilic effusion. According to the findings of pleural biopsies, our cases were classified into 2 groups. Group A (4 cases) had "basket-weaving formation" on the parietal side and inflammatory changes on the visceral side. No circulating autoantibodies were found in group A. Group B (3 cases) had no "basket-weaving formation" but only intensive inflammatory changes. These 3 cases were respectively complicated with anti-GBM antibody mediated glomerulonephritis, with acute interstitial pneumonia, and with rheumatoid arthritis and acute interstitial pneumonia. They all had circulating autoantibodies. In the course of chest roentgenograms, 6 of the 7 cases finally showed diffuse pleural thickenings which involved obliterations of costo-phrenic angles. Among them, one case developed into progressive pleural fibrosis. It was concluded that asbestos pleurisy can be classified into 2 groups according to the mechanism of occurrence, and immunological changes should be recognized as one of the mechanisms of asbestos pleurisy.

Adult↗

PubMed1990

[Long-term therapeutic effects of erythromycin and newquinolone antibacterial agents on diffuse panbronchiolitis].

The present study reviewed and summarized the long-term therapeutic effects of erythromycin or newquinolone antibacterial agents on diffuse panbronchiolitis. Various parameters before and after the treatment were analyzed in 101 patients selected from 227 diffuse panbronchiolitis patients gathered from 26 institutes in Japan. Patients had been treated with either erythromycin or newquinolone antibacterial agent for more than 3 months. Patients treated with erythromycin showed significant improvement of dyspnea on exertion, findings of chest X-ray, data on blood gas analysis, rate of ESR, titer of cold coagulation and amount of sputum, compared with patients treated with the newquinolone antibacterial agent. Among the patients treated with erythromycin, those patients with the initial high cold coagulation titer showed better improvement following treatment. However, there was no significant difference in improvement, depending upon either the duration between the time of onset of the disease, the initiation of treatment, and the initial severity of the disease.

4-Quinolones↗

PubMed1990

[Clinical evaluation of BMY-28100 for bacterial pneumonia in comparison with cefaclor in a double-blind study].

The efficacy, safety and usefulness of BMY-28100 for the treatment of bacterial pneumonia were compared with those of cefaclor (hereinafter referred to as CCL) in a double-blind study. The daily dosages were 750 mg for BMY-28100 and 1,500 mg for CCL, divided into 3 administrations daily. These drugs were administered orally for at least 14 days. A total of 172 cases were enrolled in this study. Of these, cases which deviated from the protocols were excluded from evaluations. Thus, clinical efficacy was evaluated in 124 cases, adverse reactions were evaluated in 160 cases, and abnormal laboratory test values were evaluated in 146 cases. The following results were obtained. 1. Efficacy rates ("good" or better responses) in bacterial pneumonia cases as evaluated by the subcommittee were 81.7% (49/60) in the BMY-28100 group and 89.1% (41/46) in the CCL group, thus no significant difference was found between the 2 groups. 2. Efficacy rates ("good" or better responses), as evaluated by investigators, in the same bacterial pneumonia cases which were subjected to the evaluation by the subcommittee were 83.3% (50/60) in the BMY-28100 group and 88.9% (40/45) in the CCL group, thus no significant difference between the 2 groups was found also. 3. Bacteriological response rates in bacterial pneumonia cases were 86.2% (25/29) in the BMY-28100 group and 85.7% (18/21) in the CCL group with no significant difference between the 2 groups. 4. Incidences of subjective/objective clinical adverse symptoms were 3.5% (3/85) in the BMY-28100 group and 1.3% (1/75) in the CCL group, and no significant difference was observed between the 2 groups. No significant difference was also found between the 2 groups in incidences of abnormal laboratory test values, as abnormalities were found in 21.1% (16/76) of the cases in the BMY-28100 group and 25.7% (18/70) in the CCL group. 5. As for overall usefulness of the drug in bacterial pneumonia cases, utility rates ("useful" or better evaluations) as evaluated by the subcommittee were 83.6% (46/55) in the BMY-28100 group and 90.5% (38/42) in the CCL group, and the rates as evaluated by investigators in cases judged as evaluable by the subcommittee were 78.3% (47/60) and 82.2% (37/45), respectively. There were no significant differences between the 2 groups. The utility rates as evaluated by investigators in cases in which diseases were diagnosed as bacterial pneumonia or lung abscess by investigators were 78.3% (47/60) in the BMY-28100 group and 82.2% (37/45) in the CCL group.(ABSTRACT TRUNCATED AT 400 WORDS)

Administration, Oral↗