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Biomedical subjects

S Sakamoto

Publications and source records attributed to S Sakamoto.

At least 883 records · Page 49Linked to original sources
PubMed1977

Prostaglandin F2alpha and E1 in plasma and amniotic fluid during human pregnancy and labor.

In order to elucidate the significance of PGs in human labor, PGE1 and F2alpha in biological fluid during human pregnancy and labor were measured by RIA newly developed. Analytical studies demonstrated that the levels of PGF2alpha in maternal plasma were 3.7 +/- 2.5 ng/ml a few days before parturition, 2.0 +/- 0.9 ng/ml in the first stage of labor and 1.9 +/- 1.4 ng/ml at delivery. Thus the concentrations of PGF2alpha in maternal plasma showed no significant changes around parturition. On the otherhand, the level of PGF2alpha in amniotic fluid represented a significant increase up to 44.27 +/- 32.81 ng/ml at delivery from 1.45 +/- 0.76 ng/ml before labor at 38-40 weeks of pregnancy (p less than 0.05), although it was uncertain whether this elevation was the cause or effect of uterine contraction. The concentration of PGE1 ranged from 2 to 14 ng/ml around parturition. This indicates that there was little remarkable difference between the levels of PGE1 in plasma and amniotic fluid during the last month of pregnancy and labor. Possible involvement of prostaglandins (PGs) in human labor has been discussed.

Amniotic Fluid↗
PubMed1977

[Application of non-invasive methods to assessment of left ventricular function in cardiomyopathy (author's transl)].

Left ventricular function in cardiomyopathy was studied by non-invasive methods. Various indices of left ventricular function were measured in patients with cardiomyopathy by mechanocardiography and echocardiography and were compared with indices in normal subjects and the following conclusions were obtained. 1) Patients with Congestive cardiomyopathy had high PEP/LVET, low mVcf, low EF, and low mPWV, suggesting depressed cardiac function. 2) Patients with Hypertrophic obstructive cardiomyopathy had characteristic findings, such as low DDR, high IVST/PWT, and SAM. 3) Patients with Hypertrophic non-obstructive cardiomyopathy had no characteristic changes in indices, however in some of the findings transition to Hypertrophic obstructive cardiomyopathy was suggested.

Cardiomyopathies↗
PubMed1976

[Effects of ferulic acid on FSH, LH and prolactin levels in serum and pituitary tissue of male rats (author's transl)].

The existence of substances in corn germ, which induce a positive response in pigeon crop test, has been previously reported by Okamoto and Takahashi in 1974. Following this first experiment, one of these substances was identified as ferulic acid by purification. In the present experiment FSH, LH and prolactin levels in the serum and the pituitary tissue of castrated male rats and EP (estradiol benzoate and progesterone) treated male rats were determined by radioimmunoassay at 5 to 180 min. after intravenous injection with 1 mg of ferulic acid. It was noted that FSH release only was promoted significantly at 5 min. after the injection, whereas LH and prolactin releases were inhibited at 5 to 10 min. after the injection. A rebound effect was noted in LH and prolactin releases after the injection.

Animals↗
PubMed1976

[Influence of long-term lactation on 7,12-dimethylbenz(a)anthracene (DMBA) induced rat mammary tumor (author's transl)].

Female rats of the Sprague-Dawley strain were mated 60 days after a single intravenous injection with 5 mg of 7,12-dimethylbenz(a)anthracene. In order to maintain the lactation for more than 3 weeks, 5 pups (5 to 10 days old) were attached to each mother rat throughout the experiment. Experimental rats were divided into 6 groups: 1. non-lactation (4 rats); 2. 3-week lactation (8 rats); 3. 6-week lactation (10 rats); 4. 8-week lactation (7 rats); 5. 12-week lactation (9 rats); and 6. 17-week lactation (4 rats). Lactating condition was judged from the body weight curves of the 5 pups. The appearance, number and diameter of tumors were recorded every day. The average of the tumor induction time was 140+/-74 days. The tumors were divided into 3 types: 1. progressive; 2. static; and 3. regressive. During pregnancy few tumors of the regressive type were noted. However, tumors of the progressive type increased significantly with the weeks of pregnancy. In the first week postpartum, although the total number of tumors was approximately the same as in the last week of pregnancy, the tumors of the progressive type decreased significantly and the tumors of the regressive type increased. In this period most tumors showed a tendency to regress. In the non-lactating group, the tumors of the progressive type began to increase from the fifth to seventh week postpartum without relation to the lactating period (3 to 17 weeks). Vaginal smears were examined every day in all mother rats to determine the recurrence of the estrous cycle. The first estrus appeared 7 days on an average after delivery in the non-lactating group; 27 days on an average in the 3-week lactation group; and 35 to 38 days on an average in the 6- to 17-week lactation groups. Under the condition of high prolactin level, the behavior of the tumors of the progressive type seemed to be related to estrogen. This was also supported by histological findings in the ovaries.

9,10-Dimethyl-1,2-benzanthracene↗