Search PubMed⌕ Search

Biomedical subjects

M Ishida

Publications and source records attributed to M Ishida.

At least 307 records · Page 17Linked to original sources
PubMed1991

Expression and distribution of atrial natriuretic peptide in human hypertrophic ventricle of hypertensive hearts and hearts with hypertrophic cardiomyopathy.

To investigate the ventricular expression of atrial natriuretic peptide (ANP) in human hypertrophic hearts, we conducted an immunohistochemical study of 130 endomyocardial biopsy specimens obtained from the right side of the ventricular septum (RVB), left ventricular free wall (LVB), or both from a total of 80 patients: 44 patients with hypertrophic cardiomyopathy (HCM), 14 with apical hypertrophic cardiomyopathy (APH), 13 with hypertensive hearts (HHD), and nine without hypertrophy (controls). No patients had apparent congestive heart failure. ANP was not seen in ventricular myocytes in controls but was identified in biopsy specimens of hypertrophic hearts, and its distribution was characteristic in each hypertrophic group: 15 RVB (37%) and two LVB (7%) of the HCM group, one RVB (7%) and two LVB (18%) of the APH group, and zero RVB (0%) and five LVB (46%) of the HHD group. Clinical data (including echocardiographic, hemodynamic, and angiographic data) were not directly related to ventricular ANP expression in HCM, APH, or HHD with one exception. In HHD patients, LVB specimens with ANP showed greater ventricular wall thickness than LVB specimens without ANP. According to histological data, however, the ANP-present RVB specimens of HCM or ANP-present LVB specimens of HHD had greater myocyte size than did the ANP-absent specimens. In addition, in HCM patients, the ANP-present RVB specimens showed more severe fibrosis and myofiber disarray than did the ANP-absent specimens. We conclude that a failing state and hemodynamic overload are not likely to be indispensable for ANP expression in human hypertrophic ventricles and that ventricular ANP expression occurs as a response to disease-specific changes: hemodynamic overload in HHD and histological changes such as myocardial fiber disarray, hypertrophy of myocytes, and fibrosis in HCM, which may reflect the characteristic distribution of intraventricular ANP.

Adult↗
PubMed1991

Ischemic preconditioning preserves creatine phosphate and intracellular pH.

BACKGROUND: Ischemic preconditioning slows ATP depletion and ultrastructural damage during the final episode of ischemia. To define the influence of creatine phosphate (CP) and intracellular pH (pHi) on this effect, CP and pHi were serially measured in porcine hearts without collateral circulation by using 31P-NMR spectroscopy and ultrastructural examination. METHODS AND RESULTS: Farm pigs weighing 12-15 kg were anesthetized with Fluothane. The control group underwent a single occlusion (20 minutes or 60 minutes); the preconditioned group underwent four episodes of 5-minute occlusion and 5-minute reperfusion followed by a sustained occlusion (20 minutes or 60 minutes). After ischemic preconditioning, CP increased to 115 +/- 11% (p less than 0.05) of preischemic value and ATP decreased to 84 +/- 8% (p less than 0.05) of preischemic value, but pHi returned to preischemic value. At 5 and 10 minutes of sustained ischemia, CP was significantly preserved in the preconditioned group (control group, 19 +/- 3% versus preconditioned group, 29 +/- 4% at 5 minutes; control group, 5 +/- 3% versus preconditioned group, 11 +/- 3% at 10 minutes; p less than 0.05). At 15 and 20 minutes of sustained ischemia, ATP was significantly preserved in the preconditioned group (control group, 64 +/- 3% versus preconditioned group, 73 +/- 3% at 15 minutes; control group, 51 +/- 7% versus preconditioned group, 62 +/- 2% at 20 minutes; p less than 0.05). At 10, 15, 20, and 25 minutes of sustained ischemia, pHi was significantly higher in the preconditioned group (control group, 6.5 +/- 0.05 versus preconditioned group, 6.7 +/- 0.1 at 10 minutes; control group, 6.3 +/- 0.05 versus preconditioned group, 6.6 +/- 0.06 at 15 minutes; control group, 6.1 +/- 0.1 versus preconditioned group, 6.4 +/- 0.1 at 20 minutes; control group, 6.0 +/- 0.2 versus preconditioned group, 6.3 +/- 0.1 at 25 minutes; p less than 0.05). Ultrastructural changes were milder in the preconditioned group at 20 minutes of sustained ischemia. CONCLUSIONS: In addition to ATP and ultrastructure, preconditioning preserved CP and pHi during sustained ischemia. These protective effects might be due to overshoot phenomenon of CP and/or reduced ATP consumption. The relatively longer period of preservation of pHi, which probably is the result of reduced ATP consumption, indicates its greater contribution to reducing infarct size than that of CP and ATP.

Adenosine Triphosphate↗
PubMed1991

Relation between myoglobin and cardiac dysfunction in myocarditis--immunohistochemical study of endomyocardial biopsy specimens.

To investigate the mechanism of cardiac dysfunction in myocarditis, myoglobin, an intracellular oxygen-transport, was immunohistochemically examined in biopsy specimens obtained from the right side of the ventricular septum and left ventricular free wall in 58 patients with myocarditis and 19 controls. Sections 4 microns thick were stained by the indirect immunoperoxidase method using a polyclonal antibody to human myoglobin as the primary antibody. Under light microscopy, the intensity of myoglobin immunoreactivity in the tissue section was semiquantitatively classified from grade 0 to grade 3. Then, the grade of myoglobin staining was compared with clinical, hemodynamic and histopathologic parameters. In right and left ventricular specimens, the grade of myoglobin staining was positively correlated with ejection fraction, but inversely with left ventricular end-diastolic and end-systolic volume indices. The percentage of myocytes with grade 0 was correlated with the number of mononuclear cells in the specimens. In addition, the grade of myoglobin staining in right ventricular specimens was positively correlated with the duration of illness but inversely correlated with the number of mononuclear cells. In 4 patients who had serial biopsies, the ejection fraction was improved and the grade of myoglobin staining was increased in the convalescent stage. These results indicate that myoglobin staining reflects the intensity of myocarditis and a decrease of myoglobin may be important as one of the pathogenetic factors of cardiac dysfunction in myocarditis.

Adolescent↗
PubMed1991

[Clinical study of miconazole on deep-seated fungal infections].

An investigation was made on the efficacy and the safety of miconazole (MCZ) in the treatment of deep seated mycosis. The drug was administered through intravenous drip infusion at dose levels of 800 to 2,000 mg/day to 21 cases of confirmed mycosis for which causative organisms was identified and to 32 cases to which other antibiotics considered to be appropriate had been administered at febrile stages but had failed to take effect, hence mycoses were strongly suspected. The overall clinical efficacy rate was 84.3% (43/51). Treatments were "remarkably effective" in 6 cases, "effective" in 37, "not effective" in 8 and "indeterminable" in 2. The efficacy rates were 100% (21/21) in the confirmed mycosis cases and 73.3% (22/30) in the suspected mycosis cases. The mycological efficacies in the cases for which causative strains were identified were: disappeared in 14 (66.7%), decreased in 4 (19%), unchanged in 2 (9.5%) and unknown in 1 (4.8%), thus the overall disappearance ratio was 70% (14/20). Chest X-ray showed the disappearance of shadow in 1 patient and improvements in 14 of 23 patients examined. Adverse reactions were observed in 5 of the 53 cases (9.4%). From these results, MCZ may be considered as a highly useful drug not only in the treatment of deep mycosis but also in cases for which mycosis is strongly suspected.

Adolescent↗
PubMed1991

[Effect of white matter lesions on cerebral blood flow in asymptomatic individuals: assessment by MRI and 133Xe-CBF method].

In 32 patients with asymptomatic white matter lesions (WMLs), we evaluated the age-related changes in the number of white matter lesions, cerebral blood flow (CBF), cerebrovascular resistance (CVR) and mean arterial blood pressure (MABP). CBF was measured with the intravenous 133Xe injection method. The number of WMLs in whole brain was measured by the magnetic resonance imaging. CBF decreased with advancing age (r = 0.529; p less than 0.01), while the number of WMLs (r = 0.39; p less than 0.05), CVR (r = 0.464; p less than 0.01) and MABP (r = 0.229; ns) increased with advancing age. There was a significantly negative correlation (r = -0.499; p less than 0.01) between CBF and the number of WMLs. While, CVR showed a positive correlation with the number of WMLs (r = 0.468; p less than 0.01). Multivariate regression analysis with stepwise forward selection method indicated that the number of WMLs and age were independent and negative predictors for CBF, while other factors did not. CBF decreased with a concomitant rise in CVR. On the basis of the results listed above, we assumed that ischemic damage of the white matter and/or functional suppression of distant loci due to the primary tissue damage are the best explanation for CBF reduction in asymptomatic individuals with WMLs. High resolution CBF imaging as well as evaluation of structural alterations in cerebrovascular vessels should be required to further define the mechanisms.

Adult↗
PubMed1991

[A retrospective survey of newly registered pulmonary tuberculosis patients--379 cases at 4 health centers in 1985].

Using the registration card of tuberculosis patient, a retrospective analysis was made on newly registered 379 patients with pulmonary tuberculosis in 1985 to examine the treatment duration, the outcome, the duration of registration, and bacteriological relapse. These patients were divided into three groups according to the results of bacteriological examination at the time of registration: (1) patients with positive-bacilli (Group A); (2) patients with negative-bacilli (Group B); and (3) patients without results of bacteriological examination (Group C). 1) Number of cases were 164 (43.3%) in the group A, 130 (34.3%) in the group B, and 85 (22.4%) in the group C. Sputum specimens from 68 patients (80.0%) of the group C were negative on smear, however, the results of culture were not obtained, and remaining 17 cases (20.0%) were not examined bacteriologically. 2) 54 patients (32.9%) in the group A, 25 (19.2%) in the group B, and 17 (20.0%) had a previous history of tuberculosis, respectively. 3) Number of patients with cavitary lesions at the time of registration were 105 (64.0%) in the group A, 46 (35.4%) in the group B, and 14 (16.5%) in the group C. Patients in the group A showed the highest rate of cavitary lesions. 4) Number of patients receiving treatment less than 12 months were 73 (53.3%) in the group A, 92 (85.2%) in the group B, and 47 (73.5%) in the group C, respectively. 5) 317 patients (83.6%) were omitted during 5 years of period from registration although 62 (16.4%) were still under registration even after 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Carcinoma of the gastric remnant fed by the accessory left gastric artery--a case report].

A 65-year-old female, who had undergone partial gastrectomy with Billroth II reconstruction for duodenal ulcer 22 years ago, visited our hospital with a complaint of anorexia. Roentgenogram and endoscopic examination revealed a protruding lesion on the posterior wall of the gastric remnant. An endoscopic biopsy specimen was histologically regarded as carcinoma. Proper hepatic arteriography revealed an accessory left gastric artery arising from the left hepatic artery, which was a main feeder to the tumor. Total gastrectomy with lymph node dissection and splenectomy were performed. Histology of the tumor was poorly differentiated adenocarcinoma located in the submucosal layer. To our knowledge, there is no report about the carcinoma of the gastric remnant fed by the accessory left gastric artery.

Adenocarcinoma↗
PubMed1990

A potent metabotropic glutamate receptor agonist: electrophysiological actions of a conformationally restricted glutamate analogue in the rat spinal cord and Xenopus oocytes.

The (2S,3S,4S) isomer of alpha-(carboxycyclopropyl)glycine (L-CCG-I), a conformationally restricted glutamate analogue, caused a marked depolarization of motoneurons in the isolated rat spinal cord, which was almost insensitive to CPP and CNQX. Depolarizing responses to L-CCG-I were markedly decreased by reducing the temperature of the bathing fluid. Similar results were obtained in the case of trans-ACPD, which is a metabotropic glutamate receptor agonist, but the depolarizing action of L-CCG-I was more potent than that of trans-ACPD. In Xenopus oocytes injected with poly(A)+ mRNA extracted from the rat brain, L-CCG-I induced significant oscillatory chloride currents, suggesting that L-CCG-I is a potent agonist for metabotropic-type glutamate receptors.

Amino Acids, Dicarboxylic↗
PubMed1990

Determination of fluoride ion in animal bone by microdiffusion analysis.

A microdiffusion analysis method for the determination of fluoride ion in animal bone sample was established by using a new diffusion cell. The cell is equipped with a water jacket to control the temperature. The space inside the cell is divided by a crossed-beam stand into top and bottom parts. In the bottom part, derivatization of fluoride ion to trimethylfluorosilane (TMFS) by hexamethyldisiloxane as the reagent occurs, with the volatile TMFS being absorbed into alkali placed in an open-top cup supported by the stand. The cell is placed on a magnetic stirrer to rotate the stirring bars in both reaction and absorption solutions. Stirring and elevation of temperature increase the reaction rates. Maintaining the cell at 40 degrees C for 3 h is sufficient for complete extraction of fluoride ion from the bone and its recovery. With our method, more than 10 micrograms/g of fluoride ion in bone can be assayed with a coefficient of variation of less than 3%. The fluoride levels of various rat bones were clarified.

Animals↗
PubMed1990

Unique hairpin structures occurring at the replication origin of phage G4 DNA.

Recently we reported that a DNA fragment, GCCAAAGC, forms an extraordinarily stable hairpin structure with two G-C pairs at the terminus and A-A-A stacked structure. The sequence is present at the replication origin of bacteriophage G4 ssDNA, and so on. Several kinds of possible hairpin structures, corresponding to the replication origin of phage G4, were synthesized and their secondary structures were examined. It was found that the fragments are able to form interconvertible hairpin structures depending on the length of the base-paired regions. The hairpin structure consisting of GCGAAAGC was not digested by the exonuclease activity of T4 DNA polymerase and it was stable enough to be only minimally bound by a single-stranded DNA binding protein.

Base Sequence↗
PubMed1990

Selective N-methyl-D-aspartate (NMDA) antagonists increase gastric motility in the rat.

Systemic administration of selective NMDA antagonists, such as CPP, APH, ketamine and MK-801, increased spontaneous gastric motility of the rat in a dose-dependent manner, and they prevented the NMDA-evoked depression of gastric motility. On the other hand, a broad spectrum excitatory amino acid antagonist, kynurenate, DNQX and CNQX decreased spontaneous gastric motility. Under the action of hexamethonium or chlorisondamine, CPP and MK-801 had little effect upon gastric motility. After the treatment with atropine, the motor responses to NMDA, CPP and MK-801 were hardly observed. Similar results were obtained after vagotomy.

2-Amino-5-phosphonovalerate↗
PubMed1990

In vitro and in vivo activities of T4 endonuclease V mutants altered in the C-terminal aromatic region.

Genes encoding mutants of the thymine photodimer repair enzyme from bacteriophage T4 (T4 endonuclease V) having an amino acid substitution (T127M, W128A, W128S, Y129A, K130L, Y131A, Y132A) were constructed by use of a previously obtained synthetic gene and expressed in Escherichia coli under the control of the E. coli tryptophan promoter. An in vitro assay of partially fractionated mutant proteins for glycosylase activity was performed with chemically synthesized substrates containing a thymine photodimer. T127M and K130L showed almost the same activity as the wild-type protein. Although W128S, Y131A, and Y132A were slightly active, W128A and Y129A lost activity. The results indicated that the aromatic amino acids around position 130 may be important for the glycosylase activity. Mutant T127M was purified, and the Km value was found to be of the same order as that of the wild type (10(-8) M). In vivo activities for all mutants were characterized with UV-sensitive E. coli. The results showed that substitution of Thr-127 with Met or Lys-130 with Leu did not have an effect on the survival of the bacteria but substitution of aromatic amino acids (128-132) had various effects on survival.

Amino Acid Sequence↗
PubMed1990

High cell density suspension culture of mammalian anchorage independent cells: oxygen transfer by gas sparging and defoaming with a hydrophobic net.

Gas sparging directly into the culture-broth is not done in cell culture, except when the gas flow rate is very small, because much foaming occurs. During screening of defoaming methods, foam was observed to be broken up effectively when it made contact with a net fabricated from hydrophobic materials. Providing a highly efficient oxygen supply to suspension culture was tried using the new defoaming method. In a 5 l reactor equipped with the foam-eliminating net fabricated with polysiloxane, oxygen was transferred at 21 mmole/l.h equivalent to a consumption rate of 1 X 10(8) cells/ml, even at a low oxygen gas flow rate of 0.1 cm/s corresponding to a fourth of the gas flow rate when foam leaked through the net. Perfusion culture of rat ascites hepatoma cell JTC-1 was successfully carried out in the 5 l scale culture system with the net and a hydrophobic membrane for cell filtration. The viable cell concentration reached 2.7 X 10(7) cells/ml after twenty-seven days, in spite of the nutrient-deficient condition of the lower medium exchange rate, that is, a working volume a day, and viability was maintained at more than 90%. In a 1.21 scale culture of mouse-mouse hybridoma cell STK-1, viable cell concentration reached 4 X 10(7) cells/ml. These results showed that oxygen transfer by gas sparging with defoaming was useful for high density suspension culture. A foam-breaking mechanism was proposed.

Animals↗