Search PubMed⌕ Search

Biomedical subjects

S Sakamoto

Publications and source records attributed to S Sakamoto.

At least 649 records · Page 36Linked to original sources
PubMed1985

Disorders of cobalamin metabolism.

Recent developments in our knowledge of the biochemistry and metabolism of cobalamin have given us some insight into clinical disorders. N2O, which easily induces cobalamin deficiency, both in vivo and in vitro, has greatly contributed to the investigation of the cobalamin deficient state, especially in relation to folate and amino acid metabolism. Demonstration of the cobalamin analog in human serum and a new enzyme which requires cobalamin as a coenzyme has led to recent increased interest in this field. The disorders of cobalamin metabolism will be summarized briefly as well as those areas currently of particular interest.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed1985

Synthesis and secretion of human epidermal growth factor by Escherichia coli.

A synthetic gene for human epidermal growth factor (hEGF) was joined to a sequence encoding the signal peptide of Escherichia coli alkaline phosphatase. This hybrid gene was placed under the control of the alkaline phosphatase gene (phoA) promoter in a recombinant plasmid, which was used to transfect E. coli. The hybrid protein that was expressed in host cells under conditions of phosphate limitation was processed accurately during the secretion process, and mature hEGF was recovered in the periplasmic fraction. On the other hand, no EGF was detected in the periplasmic space when the synthetic hEGF gene was not accompanied by the phoA signal sequence.

Alkaline Phosphatase↗
PubMed1985

Increased activities of thymidine kinase isozymes in human colon polyp and carcinoma.

Thymidine kinase (TK), the enzyme in the pyrimidine salvage pathway, and its isozymes were examined in 15 specimens of normal mucosa, 14 polyps and 14 carcinomas in human colon. The average TK activities in colon polyps and carcinomas were about 1.6 and 2.9 times that in normal colon mucosa, respectively. The colon TK isozymes were separated into 2 types by DEAE-cellulose column chromatography. The activity of the TK isozyme eluted with 0.1 M NaCl in buffer was 1.6-fold higher in colon polyp and 1.5-fold higher in colon carcinoma than that in normal colon mucosa. In colon carcinoma, but not colon polyp, the activity of the other isozyme eluted with buffer alone was increased to 5.1-fold that in normal tissues. As the activity of the latter isozyme was not affected by deoxycytidine triphosphate, it may be involved in DNA replication. The results suggest that increases in the activities in the former and latter TK isozymes may indicate tumorigenesis and carcinogenesis, respectively, in the human colon.

Adult↗
PubMed1985

Myocardial ischaemia produced by ergonovine-induced vasoconstriction during preexisting coronary stenosis: experimental conditions for the geometric theory.

Experiments were designed to determine the contribution of active vasomotor tone of a large coronary artery during a preexisting coronary stenosis to the production of myocardial ischaemia. The quantitative relations between ergonovine dose and systemic and coronary haemodynamic and electrocardiographic responses during various degrees of coronary stenosis were evaluated in 55 anaesthetised open-chest dogs. In the absence of coronary stenosis, intracoronary infusion of ergonovine (0.04 to 4 micrograms X min-1) had no systemic or coronary haemodynamic effects. In dogs with coronary stenosis created with intraluminal microballoon occluder, ergonovine produced marked decreases in coronary blood flow and distal coronary pressure followed by a decline in left ventricular dP/dt and ST-elevation in epicardial electrogram in the presence of moderate (28 +/- 1.1 mmHg in pressure gradient) and severe (41 +/- 1.4 mmHg), but not mild (15 +/- 0.9 mmHg) stenosis. These detrimental effects of ergonovine were dependent on its dose as well as the severity of preexisting coronary stenosis. Interventions such as aspirin pretreatment or endothelial denudation did not attenuate the coronary vasomotor response or ergonovine, but pretreatment with nifedipine (3 micrograms X kg-1 iv) prevented this response. Intravenous injection of ergonovine (4 to 15 micrograms X kg-1) in doses relevant to clinical usage during intraluminal obstruction resulted in similar changes in coronary haemodynamics as those of intracoronary ergonovine. In contrast, in dogs with various degrees of coronary stenosis produced with an externally applied constrictor device, ergonovine did not affect systemic and coronary haemodynamics. These experiments demonstrate that normal vasomotion superimposed on moderate and severe pliable coronary stenosis can cause transient myocardial ischaemia, which helps to clarify the conditions to produce myocardial ischaemia according to geometric theory.

Animals↗
PubMed1985

Reaction p

Explore the source record for details and available documents.

Journal Article↗
PubMed1985

New fetal growth curves for Japanese.

New fetal growth curves for Japanese have been made with the cooperation of 37 major medical centers throughout Japan by the sponsorship of the Ministry of Health. They are reliable in regard to the adequacy of the sample number, the accuracy of the data on gestational age and the proper processes of composing growth curves. Effect of sex and parity are significant on weight but not on length and head circumference growth curves. The light-for-dates infant is defined as below mean -1.5 SD by the statistic analysis of their morbidity. These new official fetal growth curves will solve current confusion of several fetal growth curves from different institutions in Japan.

Birth Weight↗
PubMed1985

A case of hemangiomyoma of the ureter in a child.

Herein a rare case of hemangiomyoma of the ureter in a child is reported. Benign mesodermal tumors of the ureter are not common, particularly in a child. Two cases of leiomyoma of the ureter in childhood have been reported to date. This is the first case of ureteral hemangiomyoma in a child. Nephroureterectomy was performed and the subsequent clinical course reveals no evidence of recurrence.

Child↗
PubMed1985

Some properties of large and small granules of waxy barley (Hordeum vulgare L.) endosperm starch.

Large and small starch granules were isolated and characterized from mature barley kernels with waxy endosperms. The large granules of any given waxy cultivar contained more amylose than the small granules of the same cultivar. It was also found that large granules contained a greater amount of long amylopectin B chains and had a lower fraction III:fraction II ratio, one of the structural characteristics of amylopectin, than the small granules in the same cultivar. Small granules showed a wider range of gelatinization and smaller heat of gelatinization by differential scanning calorimetry.

Edible Grain↗
PubMed1985

N-Substituted derivatives of 23-amino-4',23-dideoxymycaminosyl tylonolide. Synthesis and antibacterial activity.

23-Amino-4',23-dideoxymycaminosyl tylonolide diethyl acetal (5) has been prepared from 4',23-dideoxy-23-iodomycaminosyl tylonolide diethyl acetal (3) by treatment with sodium azide followed by selective reduction of the resulting azide (4). 23-Acylamino-23-deoxy (6 approximately 8) and 23-deoxy-23-urethane-type compounds (12 approximately 15) were further prepared. Treatment of the 23-alkylamino-4',23-dideoxymycaminosyl tylonolides (9, 10) with chloroformates gave 23-N-alkyl-23-deoxy-23-urethane-type compounds (16 approximately 21, 29, 30). 23-N-Alkyl-23-deoxy-23-(2-hydroxyethalamino and 2-methoxyethylamino)-4',23-dideoxymycaminosyl tylonolides (22 approximately 25, 27, 28) were prepared from 3 and the corresponding amines. Antibacterial activities and toxicities (for 23 and 27) of these compounds are described. toxicities (for 23 and 27) of these compounds are described.

Bacteria↗
PubMed1985

[Two cases of advanced seminoma treated with Einhorn's regimen].

A combination regimen consisting of cis-platinum, vinblastine and bleomycin was evaluated in two patients with huge metastasis to the retroperitoneal lymph nodes. Both cases were seminoma histologically. Preliminary or subsequent therapy included radiotherapy and salvage surgery. The two patients achieved complete remission. They have been free of disease for more than six and more than 30 months, respectively.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Monensin inhibits collagenase production in osteoblastic cell cultures and also inhibits both collagenase release and bone resorption in mouse calvaria cultures.

Monensin, a monovalent cation ionophore, inhibited collagenase production in mouse osteoblast-rich bone cell and clonal osteogenic cell cultures. Inhibition of parathyroid hormone-stimulated bone resorption by monensin was also studied in calvaria cultures. Collagenase activity levels in the medium decreased concomitantly with the inhibition of bone resorption by monensin, indicating that monensin inhibited bone resorption by blocking collagenase secretion from osteoblasts in bone explants.

Animals↗
PubMed1985

[Right ventricular dysplasia and dilated cardiomyopathy observed by radionuclide images].

Four cases of right ventricular dysplasia (RVD) and 28 cases of dilated cardiomyopathy (DCM) were studied. RVD was characterized clinically by syncope, sustained recurrent ventricular tachycardia with left bundle branch block patterns on the surface electrocardiogram, and right heart failure. Furthermore, moderate to severe dilatation of the right ventricle and depressed right ventricular function were apparent on radionuclide angiography. However, left ventricular dilatation and depressed left ventricular function were documented in DCM. Right ventricular volume was proportional to left ventricular volume in DCM, however, right ventricular volume was disproportionately greater in RVD. On the T1-201 perfusion image, left ventricular perfusion defects were delineated in 10 of 26 patients with DCM, and in one of four RVD patients. During two to eight year follow-up periods, six patients died suddenly five of whom had left ventricular perfusion defects. However, in 19 patients without left ventricular perfusion defects, only one sudden death was observed. A connecting link between sudden death and left ventricular perfusion defect is suggested.

Cardiac Volume↗
PubMed1985

[How to determine the prophylactic effect on postoperative infections].

With the cooperation of 13 medical institutions in the Tokyo area, the methods to determine the prophylactic effect on postoperative infections in gynecological surgery were evaluated. Two hundred and ninety-nine patients were enrolled for the study of postoperative infections, febrile morbidity and fever index following abdominal (275) and vaginal (24) hysterectomies. Prophylactic cefotiam (CTM) of 1 gram was intravenously administered twice a day postoperatively for 3 to 5 days. The rates of postoperative infections were 5.1% (14/275) in abdominal hysterectomy and 4.2% (1/24) in vaginal hysterectomy. The febrile morbidity (57.1% = 8/14) and fever index (52.3 +/- 41.1 degree hours) in the infection group were approximately about 4 times higher than those (12.3% = 32/261, and 15.6 +/- 13.7 degree hours, respectively) in the non-infection group. No significant differences were observed in age, body weight, height of patients, period of operation and blood loss between these 2 groups. These data suggested that febrile morbidity and fever index were able to indicate the prophylactic effect of antibiotics on patients undergoing abdominal and vaginal hysterectomies.

Adult↗