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Biomedical subjects

R Okamoto

Publications and source records attributed to R Okamoto.

At least 289 records · Page 16Linked to original sources
PubMed1979

Arthroscopy in spontaneous osteonecrosis of the knee.

Eight knees with spontaneous osteonecrosis were investigated through arthroscopy, and in seven the intra-articular findings were rechecked at arthrotomy performed one to two weeks later. Anbormalities in the articular cartilage were observed in detail under arthroscopy that could not be seen in roentgenograms. In the early stage of osteonecrosis, flattening and fissures in the articular surfaces, with and without formation of a cartilage flap, were useful findings in choosing intra-articular surgical procedures. In the late stage, free bodies such as cartilage plates in the joint and regeneration with fibro-cartilaginous tissue over the necrotic lesion were also important in selecting surgical treatment. In addition to roentgenographic classification of developmental stages in osteonecrosis, arthroscopy is necessary in differentiating osteoarthroses, in observing the articular surface of the femoral condyles, and in determining the stage of disease when roentgenography provided insufficient information to justify intra-articular procedures such as drilling and bone grafting.

Aged↗
PubMed1978

Sex hormone-binding globulin and estrogen receptor in breast cancer: technique and preliminary clinical results.

The binding capacities of SHBG (sex hormone-binding globulin) and ER (estrogen receptor) were measured by agar gel electrophoresis with dextran-coated charcoal treatment and also by sucrose density gradient ultracentrifugation in the sera from 19 women with breast cancer to assay the correlation between SHBG and ER in breast cancer. SHBG levels were also measured by agar gel electrophoresis with dextran-coated charcoal treatment in control sera from 20 normal women. Two kinds of 17 beta-estradiol-binding substances were recognized in the cytosol of breast cancer cells and they were confirmed to be ER and SHBG. Out of 13 postmenopausal patients with breast cancer, the SHBG levels in 6 ER-positive cases (66 +/- 13 pmol/ml plasma, mean +/- SD) were significantly higher than the levels of 10 controls (35 +/- 7.6 pmol/ml; P less than 0.005). SHBG levels in 7 ER-negative patients (34 +/- 7.9 pmol/ml plasma) did not significantly differ from the levels of the controls, but differed significantly from the levels of ER-positive patients (P less than 0.005). Out of 6 premenopausal breast cancer patients, the SHBG levels in 5 ER-positive cases (63 +/- 7.5 pmol/ml plasma) tended to be higher than the levels in 10 controls (55 +/- 4.7 pmol/ml plasma), but did not achieve statistical significance (P greater than 0.05). The findings suggest that correlation between SHBG and ER in postmenopausal breast cancer is possible, but no significant difference was noted between the SHBG levels in ER-positive premenopausal breast cancer patients and premenopausal normal women.

Adult↗
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↗
PubMed1975

Studies on pathophysiological effects of postalimentary lipemia in patients with ischemic heart disease.

The present studies were undertaken to elucidate the pathophysiological effects of postalimentary lipemia(PAL) induced by the intake of much animal fat in patients with ischemic heart disease(IHD) and the preventive measures against them. Results obtained were as follows: 1) Occurrence of augmentation of ischemic changes in ECG was demonstrated after fat intake. 2) After fat intake, lowering of arterial oxygen tension and heparin-induced increase in arterio-venous difference of oxygen tension in the forearm were observed. 3) PAL resulted in an acceleration of platelet adhesiveness as well as a shortening of plasms recalcification time and that of plasma prothrombin time. 4) It was revealed that red blood cells adsorbed fat on their membrane and then readily agglutinate together. 5) Removal of chylomicrons from the blood stream was accelerated by the intravenous injection of glucose. These results lead to the following conclusions: 1)PAL exerts a deleterious effect on the oxygen supply to the myocardium in patients with IHD and it is probably due to the disturbance of pulmonary function and that of oxygen diffusion and blood flow in the myocardium. 2) As one of preventive measures against the concurrent intake of carbohydrate in an appropriate quantity appears to be of use.

Agglutination↗
PubMed1975

The size of the corpus luteum during pseudopregnancy and pregnancy in the rat.

The corpus luteum in mature Sprague Dawley rats was weighted at the various stages of pseudopregnancy and pregancy. The average size of these corpora lutea was 1.0 +/- 0.10 mg, 1.61 +/- 0.69 mg, 1.90 +/- 0.25 mg, 3.69 +/- 0.36 mg, and 4.37 +/- 0.50 mg on day 2 of diestrus, on days 10-15 of psuedopregnancy, on days 9-10, 14, and 20 of pregnancy, respectively. The fact that the average size of the corpus luteum on days 10-15 of pseudopregnancy was larger than that on day 2 of diestrus is thought to drive from prolonged exposure of the corpus luteum to prolactin. The average size of the corpus luteum on days 9-10 of pregnancy had a tendency to be larger than that on days 10-15 of pseudopregnancy and this seems to demonstrate that the placenta secreted placental lactogen by this stage of pregnancy. The average size of the corpus luteum on day 14 of pregnancy was larger than that on days 9-10 of pregnancy. This phenomenon might be attributed to the presence of large amounts of placental lactogen secreted from the placenta between days 10 and 14 of pregnancy. Furthermore, it was noted that the size of the corpus luteum on day 20 of pregnancy was larger than that of day 14, which suggests that further secretion of placental lactogen continued after day 14 of pregnancy. As there was a remarkable decrease in the number of fetuses on day 20 of pregnancy when overiectomy was performed on day 14 of pregnancy, the ovary was considered indispensable in maintaining pregnancy in the rat.

Animals↗