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Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 1,153 records · Page 64Linked to original sources
PubMed1986

In vitro fertilization and development of ova obtained from female mice treated with aminopterin and mitomycin C.

We examined the effects of mitomycin C and aminopterin on ovulation in vivo and, fertilization, subsequent cleavage and implantation in slc-ICR female mice using methods of fertilization and culture in vitro. Chemicals were injected into mice at the MI (meiosis I) stage or 3 hours before the MI stage in order to examine their toxicity. Mitomycin C did not affect ovulation, but decreased the rate of fertilization. A high dose of mitomycin C (4 mg/kg) inhibited fertilization and the development of ova to the 2-cell stage. Aminopterin affected neither ovulation nor fertilization. At either the MII (meiosis II) stage or 3 hours before the MII stage, high doses (4 and 2 mg/kg) of mitomycin C arrested cleavage and implantation. The cleavage was blocked frequently between the 3-4 cell stage and the 5-8 cell stage. Aminopterin affected neither cleavage nor implantation.

Aminopterin↗
PubMed1986

Effects of ACNU and radiotherapy on malignant glioma.

A randomized clinical study of irradiation and irradiation combined with ACNU in the treatment of malignant gliomas was performed in order to determine if there was an enhancing therapeutic effect of ACNU given in addition to radiotherapy. An effect was defined as a reduction in tumor size, changes in neurological signs and performance status within 1 month after the completion of radiotherapy, or statistically improved survival times. Seventy-seven patients from 14 neurosurgical clinics were included in this validated study group. Radiotherapy with a total dose of 5000 to 6000 rads, given in 25 to 30 subdoses, was applied to the whole brain and to a generous field surrounding the tumor. Patients who were assigned to receive chemotherapy were given ACNU intravenously once or twice during radiotherapy at a dose of 100 mg/sq m of body surface area. The response rate (more than 50% reduction of the tumor size) was 13.5% in the group treated by radiotherapy alone and 47.5% in the group with radiotherapy and ACNU. The hematological toxicity was more severe in the group treated with radiotherapy and ACNU. Other toxicity was mild and acceptable. The survival rates of patients with astrocytoma grade III and glioblastoma multiforme at 36 months after the surgery were 48.9% and 0% for radiotherapy alone and 59.0% and 16.3% for radiotherapy plus ACNU, respectively. The differences between the survival curves were not significant at the p = 0.05 level. This study has demonstrated that, although the use of ACNU during radiotherapy suppressed malignant gliomas more than radiotherapy alone, the survival time was not extended significantly. It is necessary to continue to search for an effective chemotherapeutic regimen to prolong survival of patients with malignant gliomas.

Adolescent↗
PubMed1986

Chronic effect of a synthetic atrial natriuretic factor on the development of hypertension in young spontaneously hypertensive rats.

The chronic effect of a synthetic atrial natriuretic factor (ANF) of 25 amino acid residues on the development of hypertension in the 6-week-old spontaneously hypertensive rat (SHR) was assessed. The SHR, on regular diets or given 1% NaCl solution for drinking, were continuously infused with ANF (150 micrograms/kg per day) or vehicle (physiological saline) as controls for up to 14 days. The ANF attenuated transiently the development of hypertension in the sodium-loaded SHR, but the blood pressure returned to control levels by day 5. In SHR on regular diets ANF did not affect the development of hypertension. In addition, ANF did not induce any significant changes in urine volume, fluid intake, urinary sodium and potassium excretion, heart rate, heart weight or haematocrit in young SHR on either normal or increased sodium intake when compared with those in vehicle-infused SHR. These results suggest that ANF may exert some role via a vascular effect at the early stage of development of hypertension in young sodium-loaded SHR.

Animals↗
PubMed1986

Circulating atrial natriuretic polypeptide during exercise in patients with essential hypertension.

We studied the relationship between haemodynamic measurements and plasma atrial natriuretic peptide (ANP) levels during exercise in patients with essential hypertension. The exercise protocol consisted of three fixed work loads (25, 50 and 75 W) using a supine bicycle ergometer. Plasma ANP levels and haemodynamic indices were measured before and during each stage of exercise. Plasma ANP levels and pulmonary artery wedge pressure (PAWP) significantly increased at the maximum work load. Significant correlations of PAWP and mean arterial pressure (MAP) to plasma ANP levels were observed at four points obtained before and during each stage of exercise (PAWP, r = 0.83, P less than 0.001; MAP, r = 0.48, P less than 0.01). Furthermore, a significant inverse correlation between shortening fraction (SF), estimated by M-mode echocardiography, and plasma ANP levels at 75 W work load was also observed (r = -0.66, P less than 0.01). These results suggest that the increase of circulating ANP levels during exercise in essential hypertensive subjects may be associated with elevated left atrial pressure and arterial pressure, or left ventricular systolic dysfunction.

Adult↗
PubMed1986

[Left ventricular wall motion abnormalities evaluated by factor analysis as compared with Fourier analysis].

Factor analysis was applied to multigated cardiac pool scintigraphy to evaluate its ability to detect left ventricular wall motion abnormalities in 35 patients with old myocardial infarction (MI), and in 12 control cases with normal left ventriculography. All cases were also evaluated by conventional Fourier analysis. In most cases with normal left ventriculography, the ventricular and atrial factors were extracted by factor analysis. In cases with MI, the third factor was obtained in the left ventricle corresponding to wall motion abnormality. Each case was scored according to the coincidence of findings of ventriculography and those of factor analysis or Fourier analysis. Scores were recorded for three items; the existence, location, and degree of asynergy. In cases of MI, the detection rate of asynergy was 94% by factor analysis, 83% by Fourier analysis, and the agreement in respect to location was 71% and 66%, respectively. Factor analysis had higher scores than Fourier analysis, but this was not significant. The interobserver error of factor analysis was less than that of Fourier analysis. Factor analysis can display locations and dynamic motion curves of asynergy, and it is regarded as a useful method for detecting and evaluating left ventricular wall motion abnormalities.

Adult↗
PubMed1986

[Studies on individual fetal weight estimation by ultrasonography in multiple pregnancies].

Fetal weight estimation was tried in each fetus in 16 cases of twins and 2 cases of triplets using the formula derived from the regression analysis of fetal biometric data and actual neonatal weights in 26 cases of singleton pregnancies. The fetal biometric data used were biparietal diameter (BPD), abdominal antero-posterior diameter (APD), abdominal transverse diameter (TD), abdominal circumference (AC) and fetal femur length (FFL). The correlation between the estimated and actual weight was significant (r = 0.926) and the estimation error in neonates smaller than 2,500 g was less than 10% of the birth weight. Estimated weight differences in 16 pairs of twin pregnancies correlated well with the actual weight differences (r = 0.678). A sensitivity of 70% and specificity of 100% were revealed in the diagnosis of IUGR using the estimation formula and the intrauterine fetal growth curve. These results showed how the estimation formula derived from ultrasonically measured fetal biometric parameters, can be applied clinically but two kinds of formula with or without BPD are necessary for fetal weight estimation in multiple pregnancies as only 53% of BPD were available for fetal weight estimation.

Anthropometry↗
PubMed1986

[A double-blind comparative study on the efficacy of S6472, cefaclor, in the treatment of bacterial bronchitis].

Clinical efficacy and safety of S6472 (long active cefaclor (CCL)) and CCL were compared by a double-blind study using 248 patients with bacterial bronchitis. Patients were orally administered with either 375 mg of S6472 2 times or 250 mg of CCL 3 times daily for 7 days, and the following results were obtained. Clinical efficacy judged by a committee: The efficacy rates on acute bronchitis were 87.2% for S6472 and 82.6% for CCL, and the efficacy rates on chronic bronchitis were 70.3% for S 6472 and 64.7% for CCL. There was no significant difference between the 2 drugs in clinical efficacy. Clinical efficacy judged by doctors in charge: Results of the clinical efficacy judged by doctors in charge were similar to the efficacy judged by the committee. Bacteriological efficacy judged by the committee: Eradication rate for the S6472 group was 71.1% (32 of 45 patients) and that for the CCL group was 67.4% (29 of 43 patients). There was no significant difference between the 2 drugs in the bacteriological efficacy. Side effects and abnormal laboratory findings: Side effects were observed in 5 cases (4.2%) in the S6472 group and in 5 cases (4.0%) in the CCL group. These side effects, however, were not serious, and no remarkable abnormal laboratory values were observed. There was no significant difference between the 2 drugs in the incidence of side effects or abnormal laboratory findings. Clinical utility: When the clinical utility was expressed by the utility rate (very useful and useful), it was 79.5% in the S6472 group (117 patients) and 76.2% in the CCL group (122 patients) (judged by the committee). When the utility was judged by doctors in charge, it was 73.3% in S6472 group (120 patients) and 71.4% in CCL group (126 patients). From the above results, it has been concluded that S6472 taken twice daily is equivalent to CCL in effectiveness on bacterial bronchitis.

Adult↗
PubMed1986

Morphological studies of Escherichia coli in the urine of patients with acute simple cystitis treated with aztreonam.

The effects of aztreonam (AZT) on the morphology of Escherichia coli in the urine of 5 patients with acute simple cystitis were studied by differential interference contrast microscopy. The urine specimens were collected via catheter before, 5, 15 and 30 minutes after intravenous administration of 1.0 gm AZT. The minimum inhibitory concentration of E. coli against AZT was 0.05 microgram/ml. The mean urinary concentrations at 5, 15 and 30 minutes after administration of AZT were 481.6 micrograms/ml, 1168.2 micrograms/ml and 993.4 micrograms/ml, respectively. In 4 patients, the urinalysis became normal within 30 minutes after the administration. Filamentous cells were observed at low and high urinary concentrations of AZT. They had vacuole-like formations. These findings were characteristic morphological changes caused by AZT. In the other patient, spheroplasts and ovoid cells were observed. AZT in the urine of patients with acute simple cystitis is suggested to have a high affinity for penicillin-binding protein (PBP) 3 and moderate affinity for PBP 1a.

Acute Disease↗
PubMed1986

The deoxygenations of tosylated adenosine derivatives with Grignard reagents.

The reactions of 2'-O- or 3'-O-tosylated adenosines with Grignard reagents resulted in the formation of various products, which were deoxy or branched-chain deoxy sugar nucleosides, 1',2'-unsaturated nucleosides, 3'-deoxy-2'-keto sugar nucleosides, and so on. The convenient method for the synthesis of the 3'-deoxy-2'-keto adenine nucleoside is described.

Adenosine↗