Search PubMed⌕ Search

Biomedical subjects

S Yagi

Publications and source records attributed to S Yagi.

At least 307 records · Page 17Linked to original sources
PubMed1984

[Evaluation of regional wall motion in myocardial infarction using animation ECG gated cardiac computed tomography].

Regional wall motion of the left ventricle was evaluated in 21 patients with myocardial infarction using an animation system of gated cardiac computed tomographic (CT) images (animation gated CCT). The results obtained were compared with data by two-dimensional echocardiography (2-DE). Evaluation of the asynergic area by animation gated CCT and 2-DE: Animation gated CCT detected the following specific regions with asynergy established by 2-DE; 10/10 cases (100%) at the anterior wall of the left ventricle, 14/14 cases (100%) at the interventricular septum, and 9/11 cases (81.8%) at the infero-posterior wall. In addition, one false positive case and one negative case were observed at the lateral wall and the apex, respectively. Of 37 instances with asynergic areas established by 2-DE, 21 cases or 89.2% were detected by animation gated CCT; the sensitivity was 91.9%. Evaluation of severity of asynergy by animation gated CCT and 2-DE: The degree of asynergy evaluated by both methods was compared with each other, and the agreement was as follows: 10/10 cases (100%) at the left-ventricular anterior wall, 13/13 cases (100%) at the interventricular septum, and 7/9 cases (77.8%) at the infero-posterior wall. Evaluation of the asynergic area by nonanimation gated CCT and 2-DE: Nonanimation gated CCT detected asynergic areas ascertained by 2-DE at the following areas; 8/10 cases (80%) at the left-ventricular anterior wall, 12/14 cases (85.7%) at the interventricular septum, and 4/11 cases (36.4%) at the infero-posterior wall. The difference between animation and nonanimation gated CCT was statistically significant (p less than 0.05). The severity of asynergy could not be evaluated by nonanimation gated CCT. For the evaluation of severity as well as detection of asynergy of the left ventricle, animation gated CCT was more useful than non-animation gated CCT. False negative cases observed at the infero-posterior wall and apex were decreased by alteration of a gantry, improvement of software and hardware, and additionally by an injection of contrast medium. Animation gated CCT is considered to become a useful clinical method in evaluating myocardial infarction and other cardiovascular disease in future. However, we will need the further improvements, such as reduction of administration dosage of contrast media, shortening of film shooting and irradiation times.

Aged↗
PubMed1983

Feedback mechanism in sulpiride-induced hyperprolactinaemia.

Feedback of oestrogen on gonadotrophin release was studied in five normally cycling normoprolactinaemic women who were rendered moderately hyperprolactinaemic by oral administration of sulpiride (150 mg daily) for 11 consecutive days. Five patients with peptic ulcer, who had been given 150 mg of sulpiride for 3-18 months and had chronic marked hyperprolactinaemia were also studied. Ethinyl oestradiol (200 micrograms) was administered by mouth daily for 4 consecutive days and serum concentration of prolactin, luteinizing hormone (LH), follicle stimulating hormone (FSH) and oestradiol were measured by a double-antibody radioimmunoassay for 11 days. Oral administration of ethinyl oestradiol caused an initial decrease followed by a rebound of LH with a peak in all the women tested. The serum FSH levels showed only the initial decrease, followed by a slight rebound. Serum oestradiol levels decreased during oral administration of ethinyl oestradiol in all the women. The results of the present investigation suggest that oestrogen feedback effect on LH release is maintained in sulpiride-induced hyperprolactinaemic women as well as in women with normal cycles.

Adult↗
PubMed1983

Body fluid distribution in the maintenance of DOCA-salt hypertension in rats.

Body fluid volumes and their relation to mean arterial pressure and plasma renin activity (PRA) were examined in heminephrectomized rats after 4 wk of treatment with deoxy-corticosterone acetate (DOCA) and placed on one of three levels of salt intake, either high (D-HS), normal (D-NS), or low (D-LS); sham-operated rats, which received heminephrectomy and no DOCA treatment, also received high (S-HS), normal (S-NS), or low (S-LS) intakes of salt. Body fluid volumes were measured as the distribution volumes of radioiodinated serum albumin, 35SO4, and tritiated water for plasma volume (PV), extracellular fluid volume (EFV), and total body water (TBW), respectively. Approximately the same degrees of hypertension occurred in the D-HS and D-NS rats, but the D-LS rats were normotensive. PV and EFV were increased only in the D-HS rats, with no prominent changes occurring in the D-NS rats. Intracellular fluid volume (ICF) was not changed in the D-NS rats when compared with the S-NS rats. The ratios of PV/EFV and EFV/TBW in the DOCA-treated groups on high or normal salt were not different from their controls. PRA was greatly suppressed in the D-HS and D-NS rats when compared with all other groups. In another group of D-HS rats, sodium was restricted for 2 wk; in this group the mean arterial pressure fell to control levels without significant changes in PV, but interstitial fluid volume was reduced to normal levels. These results demonstrated that 1) in DOCA-salt hypertensive rats there is expansion of body fluid volumes that are proportionally distributed among the PV, EFV, and ICF; 2) increases in body fluid volumes are not necessary for DOCA to maintain hypertension; 3) a certain minimal amount of dietary sodium is necessary for the development and maintenance of hypertension; and 4) following DOCA treatment the suppression of PRA is not due solely to expansion of body fluid volumes.

Animals↗
PubMed1983

Population of K-lymphocytes in various kinds of thyroid disease.

We have measured the population of Killer (K) lymphocytes in the peripheral blood of 108 patients with various kinds of thyroid disease. In the patients with Hashimoto's thyroiditis and Graves' disease, the relative and absolute numbers of K-lymphocytes were significantly lower than those seen in healthy controls (p less than 0.001), and the longer the duration of medication, the lower the K-lymphocyte population. However, there was no apparent correlation between the serum titers of thyroid autoantibodies and the K-lymphocyte population. In the patients with malignant and benign thyroid tumors, the relative and absolute numbers of K-lymphocytes significantly decreased when compared with those of controls (p less than 0.001), the decrease was more prominent after surgical operation than before operation. A prominent decrease in the K-lymphocyte population was evoked to maximum 2 to 4 weeks after surgical operation. The patients with both malignant and benign tumors having abundant lymphocytic infiltration in their surgical specimens generally revealed a lower K-lymphocyte population than those having no lymphocytic infiltration.

Adult↗
PubMed1982

Production of 2-Keto-l-Gulonic Acid from d-Glucose by Two-Stage Fermentation.

A practical method for the production of calcium 2-keto-l-gulonate (an intermediate in the Reichstein synthesis of l-ascorbic acid) from d-glucose has been established by using a two-stage fermentation system. d-Glucose was first converted to calcium 2,5-diketo-d-gluconate by a mutant strain of Erwinia sp. in a medium containing d-glucose, corn steep liquor, (NH(4))(2)HPO(4), and CaCO(3). After a 26-h cultivation, 328.6 mg of calcium 2,5-diketo-d-gluconate per ml was obtained, with a 94.5% yield from d-glucose. This broth was used directly for the next conversion without removal of cells by treatment with sodium dodecyl sulfate. The stereospecific reduction of calcium 2,5-diketo-d-gluconate to calcium 2-keto-l-gulonate was performed with a mutant strain of Corynebacterium sp. When the cell growth reached a maximum (about 16 h) in a medium containing d-glucose, corn steep liquor, NaNO(3), KH(2)PO(4), and trace elements, NaNO(3) was added to the culture, and then the calcium 2,5-diketo-d-gluconate broth was fed over a period of about 50 h. Since the mutant strain requires a hydrogen donor for reduction, the calcium 2,5-diketo-d-gluconate broth was mixed with d-glucose before being fed. The results of four two-stage fermentations in 10-m conventional fermentors showed that an average of 106.3 mg of calcium 2-keto-l-gulonate per ml was obtained, with a 84.6% yield from d-glucose, the starting material of calcium 2,5-diketo-d-gluconate production. Calcium 2-keto-l-gulonate was stable in the broth. Neither 2-keto-d-gluconic acid nor 5-keto-d-gluconic acid was detected in the final broth.

Journal Article↗
PubMed1982

Pituitary and ovarian response to luteinizing hormone releasing factor in normal and sulpiride-induced hyperprolactinemic women.

Five Japanese women with regular menstrual cycles (control group) and 5 sulpiride-induced hyperprolactinemic women (sulpiride group) were given a 100-microgram synthetic luteinizing hormone releasing factor (LRF) intravenously, on the 20th day of the menstrual cycle and on the 10th day of the next cycle. The mean responses of luteinizing hormone and follicle-stimulating hormone to LRF in the sulpiride group were higher than those in the controls. Despite enhancement of the gonadotropin levels, the mean response of estradiol was suppressed significantly in the sulpiride group in the luteal and follicular phase of the menstrual cycle. However, the mean response of progesterone was not statistically different, in either group, in the luteal phase. The results suggest that sulpiride-induced hyperprolactinemia exerts an inhibitory effect on steroidogenic activity in estradiol but not in progesterone in the ovary.

Adult↗
PubMed1982

Mechanism of action of dantrolene sodium, a peripherally acting muscle relaxant.

The mechanism of action of dantrolene sodium, a peripherally acting muscle relaxant, is reviewed. It does not alter action potentials or responses of the contractile proteins to Ca. The amount of Ca acting on the contractile proteins during twitch must, therefore, be reduced, but since Ca uptake by the SR is not altered, Ca release from the SR must be reduced by the drug. Other characteristics of this drug and their clinical implications are discussed.

Action Potentials↗
PubMed1982

Tension-pCa relation and sarcoplasmic reticulum responses in chemically skinned smooth muscle fibers.

Properties of bundles of smooth muscle fibers in which the surface membrane has been rendered highly permeable by chemical treatment (saponin) are described. These preparations are termed chemically skinned smooth muscle fiber bundles. Thin bundles were isolated from guinea pig teniae ceci and skinned in a relaxing solution by treatment with 50 micrograms/ml saponin for 20-30 min. Because Ca2+ sensitivity progressively decreased on repeating contractions or on incubating in a relaxing solution, the tension-pCa (-log10 [free Ca2+]) relationship was determined soon after the skinning by a single contraction in which the [free Ca2+] was increased in a stepwise manner. Unlike skinned skeletal muscle fibers, in skinned smooth muscle fiber bundles the tension-pCa relationship was not affected appreciably by the changes in pH from 6.4 to 7.2, in ionic strength from 0.15 to 0.30 M, or in [MgATP] from 0.4 to 8 mM. The saponin-treated smooth muscle fiber bundles retained a functional sarcoplasmic reticulum (SR). Ca can be loaded in the SR if the [free Ca2+] is in the micromolar range and MgATP is present and can be released by an application of caffeine. Mitochondria also appear to be functional in saponin-treated fibers.

Adenosine Triphosphate↗
PubMed1981

Increased risk of malignant transformation of hydatidiform moles in older gravidas: a cytogenetic study.

Cytogenetic studies were performed in 35 cases of complete hydatidiform mole, and the results were correlated with maternal age and other clinical parameters. The rate of occurrence of aneuploid cells in the 18- to 39-year age group was 19% of the total cells; the rate in the 43- to 52-year age group was 25%. The rate of aneuploid cells between 2n and 3n was 20% in the latter group but only 7% in the former group. Aneuploid cells were not found in normal villi but were found to predominate in invasive mole and choriocarcinoma. These results suggest that hydatidiform mole may have a greater potential for malignant transformation in patients 40 years and older than in younger patients.

Adult↗