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Biomedical subjects

T Takeuchi

Publications and source records attributed to T Takeuchi.

At least 937 records · Page 52Linked to original sources
PubMed1993

Structures of enzymatically modified products of arbekacin by methicillin-resistant. Staphylococcus aureus.

Only a limited number of strains of methicillin-resistant Staphylococcus aureus (MRSA) moderately resistant to arbekacin (ABK) have been isolated clinically. Three inactivated products of ABK have been obtained by reaction with excess amounts of a crude enzyme preparation extracted from an ABK-resistant MRSA strain (MIC, 25 micrograms/ml). The 2"-O-phosphate was the major product together with small amounts of the 6'-N-acetate and the double modification product. The structures of these modification products were determined by MS and NMR spectral analyses.

Aminoglycosides↗
PubMed1993

Anthracycline metabolites from baumycin-producing Streptomyces sp. D788. II. New anthracycline metabolites produced by a blocked mutant strain RPM-5.

A daunorubicin-blocked mutant strain RPM-5 derived from a new baumycin-producing Streptomyces sp. D788 accumulated a major precursor metabolite D788-1 (10-carboxyl-13-deoxocarminomycin) and nine minor metabolites in the culture broth. Five among them were new with a substituent at C-10 or the altered side chains at C-9. Isolation, purification and identification of all anthracycline metabolites produced by strain RPM-5 are described with their antitumor activities against L1210 cells.

Animals↗
PubMed1993

Isolation and structure determination of novel phosphatidylinositol turnover inhibitors, piericidin B5 and B5 N-oxide, from Streptomyces sp.

In the course of a screening program for inhibitors of epidermal growth factor (EGF)-induced phosphatidylinositol turnover in human epidermoid carcinoma cell line A431, we discovered two novel compounds of the piericidin family from the culture broth and mycelia of a Streptomyces strain MJ288-OF3. We named them piericidin B5 and B5 N-oxide. By NMR and mass spectrometric analyses, the molecular formulas of piericidin B5 and B5 N-oxide were determined to be C27H41NO4 (MW 443) and C27H41NO5 (MW 459), respectively. Piericidin B5 and B5 N-oxide inhibited phosphatidylinositol turnover of A431 cells with IC50S of 10.0 micrograms/ml and 1.1 micrograms/ml, respectively.

Anti-Bacterial Agents↗
PubMed1993

Benastatins C and D, new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. Production, isolation, structure determination and biological activities.

Benastatin C, a new member of the benastatins, has been isolated from the culture broth of Streptomyces sp. MI384-DF12. The structure of benastatin C was elucidated as 2-decarboxy-benastatin A by NMR studies. Benastatin D, 2-decarboxybenastatin B, was derived from benastatin B. Benastatins C and D showed inhibitory activities against human pi class glutathione S-transferase (GST pi) and excellent stimulatory activities on the murine lymphocyte blastogenesis in vitro.

Animals↗
PubMed1993

Inhibition of angiogenesis by erbstatin, an inhibitor of tyrosine kinase.

Here we describe the inhibitory effect of erbstatin, a specific tyrosine kinase inhibitor, on in vivo angiogenesis. Inhibition of angiogenesis was determined in a bioassay system involving chorioallantoic membranes of growing chick embryos. Erbstatin produced a dose-dependent inhibitory action on embryonic angiogenesis. This inhibition occurred at as small a dose as 10 ng/egg and the ID50 value was 80 ng/egg. To analyze this inhibition, in vitro experiments involving vascular endothelial cells were also performed. Erbstatin affected the proliferation of vascular endothelial cells, one of angiogenic components. This inhibition was dose-dependent, the IC50 value being 3.6 microM. These data indicate that erbstatin-sensitive tyrosine kinase(s) is involved in angiogenic endothelial cell proliferation, and that experiments involving erbstatin will provide an important due to understand a mechanism of angiogenesis.

Animals↗
PubMed1993

Bequinostatins A and B new inhibitors of glutathione S-transferase, produced by Streptomyces sp. MI384-DF12. Production, isolation, structure determination and biological activities.

New benzo[a]naphthacenequinone metabolites, designated bequinostatins A and B, have been isolated from the culture broth of the benastatin-producing strain Streptomyces sp. MI384-DF12. The structures of bequinostatins A and B were determined by spectral analyses to be 5,6,8,13-tetrahydro-1,6,7,9,11-pentahydroxy-8,13-dioxo-3- pentylbenzo[a]naphthacene-2-carboxylic acid and 2-decarboxybequinostatin A, respectively. Bequinostatin A showed considerable inhibitory activity against human pi class glutathione S-transferase (GST pi).

Animals↗
PubMed1993

Delaminomycins, novel nonpeptide extracellular matrix receptor antagonist and a new class of potent immunomodulator. II. Physico-chemical properties and structure elucidation of delaminomycin A.

Delaminomycins, novel extracellular matrix receptor antagonists, have been isolated from a culture broth of Streptomyces albulus MJ202-72F3. The structure of delaminomycin A was determined to be 3-[[2-[(3E,5E)-2,8-dihydroxy-7-methyl-3,5-decadienyl]- 1,6,8- trimethyl-1,2,4a,5,6,7,8,8a-octahydro-1-naphthyl]carbonyl]-5- hydroxypyrrolidine-2,4-dione by analyses of spectral properties and chemical studies.

Adjuvants, Immunologic↗
PubMed1993

[Pre and postoperative left ventricular volume and function in infants and children with total anomalous pulmonary venous return].

From January, 1989, to December, 1991, 36 consecutive patients with total anomalous pulmonary venous return (TAPVR) underwent intracardiac repair (ICR) in our institute. We studied the relationship between the size of atrial septal defect (ASD), age and preoperative left ventricular end-diastolic diameter (LVEDD) in 28 patients with regression analysis. There was no statistical relationship between the size of ASD, age and LVEDD. We measured LVEDD, RV to LV pressure ratio (RVP/LVP) and LV fractional shortening (LVFS) using two dimensional echocardiography in 15 patients, prior to and following ICR. LVEDD increased from 1.16 +/- 0.40 cm to 1.62 +/- 0.28 cm immediately following ICR, and then increased to 1.79 +/- 0.34 cm one month following ICR again. LVFS decreased from 38% to 35% immediately following ICR but still remained within normal range (normal range 28-45%). RVP/LVP decreased from 1.0 to 0.69 immediately following ICR, and to 0.39 one month following ICR. We concluded that the decrease of preoperative LV end-diastolic volume in TAPVR was not due to the decrease of LV preload but to anterior deviation of the ventricular septum caused by high RV pressure. There was significant increase of LV volume immediately following ICR, but LVFS maintained in normal range. This study suggested that small LV volume in patients with TAPVR did not influence the surgical results.

Echocardiography↗
PubMed1993

[The EEG pattern in the growing Japanese black calves].

Developmental EEG examination was performed in ten Japanese Black calves aged from 1 week to 10 weeks. The EEG was markedly influenced by the level of consciousness. In the alert wakefulness, the EEG was high frequency, low voltage pattern. In the wakefulness, the dominant activity was low frequency, and low voltage, high frequency activity was superimposed. In the drowsiness, the EEG was high voltage, low frequency activity pattern. In the sleep, markedly high voltage, low frequency activity was dominant. These four EEG patterns observed from the 1st week to the 10th week. During the course of the examination, high frequency, low voltage activity increased, so the EEG pattern gradually developed to the 10th week of age. In the wakefulness, theta wave and alpha wave dominant pattern was observed in seven calves. This pattern was observed after the 2nd week of age, thereafter incidence of this pattern increased to the 5th or 6th week. The frequency of theta wave and alpha wave dominant pattern increased from 6.0-7.5 Hz at the 3rd week to 7.5-9.0 Hz at the 10th week. As described above, the development of the central nervous system has attained the considerable level in the newborn calves, and thereafter continue to develop.

Age Factors↗
PubMed1993

[Visual evoked potentials (VEPs) by leadings on scalp and dura in rabbits].

Visual evoked potentials (VEPs) were obtained from five rabbits. Responses to the photic stimulation were recorded by leading on scalp and dura. Stimulating conditions were changed in order of binocular, monocular (left and right) and screened binocular. The VEP waveforms leading on scalp and dura were composed of five positive and four negative peaks. The amplitude of the VEP leading on dura was about five times larger than that of the VEP leading on scalp. The VEP evoked by the monocular stimulation was characterized by the decreased amplitude in the ipsilateral hemisphere to the stimulated eye. It is furthermore characteristic in the dural recording that the major negative peaks in the early component disappeared in the same side as the stimulated eye. These differences in the VEP evoked by the monocular stimulation might reflect that the most projection of optic nerve cross at the optic chiasm in rabbits.

Animals↗
PubMed1993

Hemiballism-hemichorea induced by subcortical ischemia.

Four patients presented with hemiballism-hemichorea as a clinical manifestation of white matter ischemia. These patients illustrate "positive" motor phenomena rather than limb weakness as a consequence of cerebral ischemia. In each patient, the involuntary movements disappeared following worsening of paresis. Subcortical white matter infarction in three patients and hemodynamic hypo-perfusion in the cerebral hemisphere contralateral to dyskinetic movements were possible causes. Neuroradiologically, none had pathological changes in the vicinity of the subthalamic nucleus. We presume from these observations that ischemia of the subcortical white matter, without involvement of the basal ganglia or the subthalamic nucleus, may cause hemiballism-hemichorea.

Aged↗
PubMed1993

[A case of osteosarcoma of the rib with bloody pleural effusion].

A case is reported of osteosarcoma of the 11th rib in a 38-year-old woman who presented with dry cough and dyspnea due to bloody pleural effusion and the literature on osteosarcoma of the rib in Japan is reviewed. Osteosarcoma was suggested by roentgenologic findings and examination of a percutaneous needle biopsy specimen. Therefore, we administered chemotherapy, but the tumor showed progressive expansion and invasion, causing paraplegia. The patient died on the 282nd day of admission. We performed an autopsy and diagnosed osteosarcoma histologically. The tumor was covered by a hypervascular capsule, suggesting its association with the bloody pleural effusion. Osteosarcoma of the rib has not been previously reported in association with bloody pleural effusion. Considering the prognosis and characteristics of such tumors, we recommend prompt diagnosis in cases presenting with bloody pleural effusion.

Adult↗
PubMed1993

[Shunt indication of CSF circulatory disturbance with cerebral atrophy (atypical normal pressure hydrocephalus): evaluation of serum alpha 1-antichymotrypsin and pressure wave on epidural pressure monitoring].

PURPOSE: The purpose of this study was to evaluate serum alpha 1-antichymotrypsin (alpha 1-ACT) and pressure wave on continual epidural pressure (EDP) monitoring as the indices for shunt operations in CSF circulatory disturbance associated with cerebral atrophy (atypical normal pressure hydrocephalus: ANPH). METHOD: The subjects adopted were 10 patients (aged 48-79, averaging 64.9, male: female = 8.2). V-P shunt was performed on all the cases, and venous blood was collected from the internal jugular vein before and after the operation to measure serum alpha 1-ACT value (nephelometry method, SRL Co.). Continual measurement of EDP was made preoperatively (Geltec Co.). A comparative assessment was made regarding the preoperative alpha 1-ACT value and appearance or not of pressure wave at EDP in the group whose symptom was improved by shunt (effective group: E) and the other group (non-effective group: NE). RESULTS: 1. The cases were 6 in group E and 4 in group NE. 2. The mean values of the preoperative alpha 1-ACT were 43.47 +/- 8.08mg/dl in group E and 63.68 +/- 5.48mg/dl in group NE. The former exhibited evidently low values, and all the cases whose values were less than 55mg/dl belonged to group E (p < 0.001). 3) Pressure wave (A or B wave) at EDP were observed in 5 cases, all in group E. CONCLUSION: 1. Serum alpha 1-ACT value can be regarded as an index for shunt indication for ANPH, and the value was lower in group E than group NE. The value at the boundary between effectiveness and ineffectiveness was 55 mg/dl. 2. Appearance of pressure wave at measurement of EDP was observed in all of group E. 3. Shunt operation should be taken into consideration for ANPH patients whose preoperative serum alpha 1-ACT value is low (less than 55mg/dl) and in whom pressure wave emerges at continual measurement of EDP, even though their cerebral atrophy is found to be severe by CT.

Aged↗
PubMed1993

[Study of cell populations of bronchoalveolar lavage fluid in patients with pneumonia due to Chlamydia psittaci and Mycoplasma pneumoniae].

We have performed bronchoalveolar lavage (BAL) examination in 27 cases; 5 with Chlamydial pneumonia, 7 with Mycoplasmal pneumonia and 15 in the control group (5 non-smokers, 10 smokers), and the following results were obtained. 1. In Chlamydial pneumonia and Mycoplasmal pneumonia, the cell population of alveolar macrophages in BALF decreased (p < 0.01) and that of lymphocytes increased compared with control group (p < 0.01). 2. In all cases of Mycoplasmal pneumonia without peripheral eosinophilia, the cell population of eosinophils in BALF increased compared with cases of Chlamydial pneumonia (p < 0.05). These results indicate that lymphocytes played the main role in the immune host defense in Chlamydial pneumonia, whereas infiltration of lymphocytes and eosinophils into the pneumonic lesion occurred in Mycoplasma pneumoniae infection.

Adolescent↗