Search PubMed⌕ Search

Biomedical subjects

S Sakamoto

Publications and source records attributed to S Sakamoto.

At least 613 records · Page 34Linked to original sources
PubMed1986

Increased activities of thymidine kinase isozymes in human mammary tumours.

Thymidine kinase, the enzyme in the pyrimidine salvage pathway, and its isozymes were examined in 10 specimens of normal mammary gland, 10 fibroadenomas and 11 adenocarcinomas in human breasts. The average thymidine kinase activities in fibroadenomas and adenocarcinomas were about 3 and 8 times that in normal mammary gland. The mammary thymidine kinase isozymes were separated into two types by diethylaminoethyl (DEAE) cellulose column chromatography. The activity of the thymidine kinase isozyme eluted with 0.1 M sodium chloride in buffer was twofold higher in fibroadenomas and fourfold higher in adenocarcinomas than that in normal tissue. In adenocarcinomas, but not fibroadenomas, the activity of the other isozyme eluted with buffer alone was increased to 22-fold that in normal tissues. As the activity of the latter isozyme was not affected by deoxycytidine triphosphate, it may be involved closely in DNA replication.

Adenocarcinoma↗
PubMed1986

Depersonalization in early adolescence.

Depersonalization is a comparatively rare disease in the psychiatric field. Particularly, its occurrence in early adolescence or even before seems to be quite uncommon. We have observed 120 cases of depersonalization, of which only 16 cases had their onset before the age of 15. Among them, we will present here 6 cases for which a detailed observation was available. It is very difficult for these minors to put their feeling into verbal expressions because the experience of depersonalization is a "negative symptom." Adult patients can explain metaphorically how they feel. However, children can use only similes. Therefore, in the case of depersonalization, children have more difficulty in expressing their feeling than adults. This might cause to clinically overlook depersonalization in children. Even in our observation of the cases reported here, we found after a while that their complaints actually meant experiences of depersonalization, although their explanations were at first obscure. These 6 cases showed common personality traits that they are passive in interpersonal relationship and that they easily become frustrated or hold a sense of inferiority even at trifles.

Adolescent↗
PubMed1986

Morphological and immunological change in the predominant type of leukaemic cells in a patient with T-cell chronic lymphocytic leukaemia.

A case of T-cell chronic lymphocytic leukaemia is described. Intracerebellar tumour was demonstrated by the characteristic feature of contrast-enhanced computerized tomography and was evidenced by surgical procedure. Histological examination revealed lymphocyte infiltration in the cerebellum. Initially, the majority of leukaemic cells were mature, medium-sized lymphocytes with surface marker phenotype of E+, OKT3+, OKT4+, OKT6-, OKT8-. In the terminal stage, large atypical lymphocytes which were morphologically distinct from the original lymphocytes and had different surface marker phenotype of E+, OKT3+, OKT4-, OKT6-, OKT8+, Leu7+ became increasingly prominent. The remaining medium-sized lymphocytes were morphologically and immunologically unchanged. Subsequently, the disease developed to a more aggressive pattern and the patient died in spite of chemotherapy.

Adult↗
PubMed1986

Regulation of coronary blood flow by counteraction of coronary vascular alpha and beta adrenergic activation during experimental pliable coronary stenosis.

In order to evaluate the role of adrenergic receptor-mediated vasomotions of large epicardial coronary arteries in changing coronary blood flow (CBF), the effects of intracoronary norepinephrine (NE), 1.0 microgram/min, were examined in dogs with coronary stenosis which preserved stenosis vasomobility. In untreated dogs, NE caused no significant changes in CBF and stenosis resistance (SR). In dogs treated with propranolol, NE decreased CBF by 65 +/- 7.0% (mean +/- SE) and produced 12-fold intensification of SR followed by LV dP/dt reduction. Similar detrimental responses to NE were observed in dogs treated with atenolol. In dogs treated with phentolamine, NE increased CBF by 33 +/- 5.6% and decreased SR by 65 +/- 7.1%. When NE was administrated directly distal to the stenosis to exclude responses of the stenosed coronary segment, NE failed to affect CBF and SR. These results indicated that alpha receptor stimulation intensified stenosis severity, profoundly decreased CBF and evoked myocardial ischemia, whereas beta stimulation dilated coronary stenosis and increased CBF. The net effects of NE were due to balanced alpha and beta stimulation. Thus, disproportionate activation of alpha and beta (probably beta 1) adrenergic receptors in large coronary arteries with pliable stenosis could modulate their tone and plays an important role in the regulation of CBF.

Adrenergic alpha-Antagonists↗
PubMed1986

Priming procedure and cell isolation for study on luteal cell response to peptide hormone in the rat.

The objective of this study was to develop a method of isolating luteal cells from the ovaries of immature rats pretreated with pregnant mare serum gonadotrophin (PMSG). After the ovaries were digested by collagenase and trypsin, the corpora lutea were obtained from the tissues, gently pressed in a test tube, and then placed on a sucrose density gradient. The two bands that appeared in the tube after centrifugation were designated S1 (top band) and S2 (bottom band). Progesterone and 20 alpha-dihydroprogesterone (20 alpha-DHP) secreted by the isolated cells during short-term incubation were measured by radioimmunoassay (RIA). A larger amount of progesterone, i.e., 60 to 260 ng/10(5) cells, was secreted by S1 cells than by S2 cells during the 18-h incubation. These results suggest that this simple procedure for isolation of luteal cells may provide a suitable model for in vitro studies of the luteal function.

20-alpha-Dihydroprogesterone↗
PubMed1986

Human epidermal growth factor in gastric carcinoma as a biologic marker of high malignancy.

The presence of human epidermal growth factor (hEGF) was studied in a total of 210 gastric carcinomas comprising 52 early carcinomas, 113 advanced carcinomas and 45 scirrhous carcinomas. An immunohistochemical study revealed no hEGF-immunoreactivity in early gastric carcinomas, while hEGF-positive tumor cells were detected in 24 (21.2%) of the 113 advanced carcinomas and in 15 (33.3%) of the 45 scirrhous carcinomas. The incidence of hEGF-immunoreactivity in well-differentiated adenocarcinomas was significantly higher than that in poorly differentiated adenocarcinomas (P less than 0.05). Moreover, hEGF-immunoreactive tumor cells were observed in 13 (30.4%) of the 42 scirrhous poorly differentiated adenocarcinomas, the incidence being significantly higher than that in non-scirrhous poorly differentiated adenocarcinomas (P less than 0.05). The average hEGF content in the tumor tissue estimated by radioimmunoassay was 3.77 +/- 0.61 (mean +/- SE) ng/g wet weight in immunohistochemical hEGF-positive tumors and 2.19 +/- 0.18 ng/g wet weight in hEGF-negative tumors, the difference being significant (P less than 0.05). Patients with hEGF-positive carcinomas (excluding scirrhous carcinomas) had much worse prognosis than those with hEGF-negative carcinomas. These results suggest that EGF produced by tumor cells plays an important role in the invasive growth and productive fibrosis of gastric carcinoma and also serves as a biologic marker of high malignancy in patients with gastric cancers.

Adenocarcinoma↗