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Biomedical subjects

R Sasaki

Publications and source records attributed to R Sasaki.

At least 361 records · Page 20Linked to original sources
PubMed1977

[The tentorial meningioma fed by "marginal tentorial artery" arising from the external carotid artery--a case report and review of literature (author's transl)].

It is well known that a Bernasconi-Cassinari artery is an important finding at diagnosis of the abnormality in tentorium. Since Bernasconi and Cassinari reported the artery in 1956, many reports have been presented and showed that the artery arose from the intracavernous portion of the internal carotid artery. We presented a 54-year-old female with tentorial meningioma. In selective external carotid angiography, the artery feeding the tumor was revealed arising from the accessory meningeal artery, which came off the internal maxillary artery and passed into the carnium through the foramen ovale, and took the same course of "Bernasconi-Cassinari artery". This angiographic finding suggests that it is possible for marginal tentorial artery to arise from an external carotid arterial system. It is said in the anatomical studies, when the trunk of primitive maxillary artery which is one of maxillo-carotid anastomotic arteries in fetus regresses, "marginal tentorial artery" usually remains linked to the internal carotid artery. But, if this transition of "the artery" from the external to the internal carotid artery failed, it is easily conceived the artery results in the origin of accessory meningeal artery, a branch of the external carotid artery.

Brain Neoplasms↗
PubMed1976

Multifunctional enzyme, bisphosphoglyceromutase/2,3-bisphosphoglycerate phosphatase/phosphoglyceromutase, from human erythrocytes. Evidence for a common active site.

Bisphosphoglyceromutase and 2,3-bisphosphoglycerate phosphatase activities responsible for 2,3-bisphosphoglycerate metabolsim in human red cells are displayed by the same enzyme protein which has phosphoglyceromutase activity [Sasaki, R., et al. (1975) Eur J. Biochem. 50, 581-593]. This enzyme was subjected to chemical modification by trinitrobenzenesulfonate. The three enzyme activities were inactivated by trinitrobenzenesulfonate at the same rate. The sulfhydryl content of the enzyme was unchanged during trinitrophenylation, indicating that derivatization was through the amino group. Trinitrophenylation of about one amino group per mole of the enzyme resulted in complete loss of the three activities. Both 2,3-bisphosphoglycerate and 1,3-bisphosphoglycerate inhibited trinitrophenylation and effectively protected the enzyme from inactivation. Although monophosphoglycerates did not show any protective effect at concentrations which should be adequate based upon their kinetic constants, they were protective at higher concentrations. Inactivation by trinitrophenylation was an apparent first-order reaction. The dissociation constant of the enzyme - 2,3-bisphosphoglycerate complex was determined by analyzing the first-order reaction on the assumption that the protective effect of 2,3-bisphosphoglycerate was due to competition with trinitrobenzenesulfonate. The dissociation constant was in good agreement with kinetic constants of 2,3-bisphosphoglycerate in the enzyme reactions, which indicated that 2,3-bisphosphoglycerate did indeed exert its protective effect through competition with trinitrobenzenesulfonate for an amino group of the enzyme. The protective effect of monophosphoglycerates could be rationalized with kinetic evidence that 2-phosphoglycerate at high concentrations interacts with the 2,3-bisphosphoglycerate binding site. These results indicate that the enzyme exhibits the three enzyme activities at a common active site at which one amino group essential for binding of bisphosphoglycerates is located. Based on the multifunctional properties of this enzyme, a possible mechanism was discussed for regulation of 2,3-bisphosphoglycerate metabolism in human red cells.

Binding Sites↗
PubMed1976

Subunit structure and multifunctional properties of yeast phosphoglyceromutase.

1. A new and efficient method for preparation of pure phosphoglyceromutase from baker's yeast (Saccharomyces cerevisiae) is described. Proteolytic alterations of the enzyme during extraction can be minimized by grinding the dried yeast with aluminium oxide at low temperature. 2. Yeast phosphoglyceromutase contains four highly similar, probably idential subunits of molecular weight 28000, a conclusion based on the following observations. Polyacrylamide gel electrophoresis containing dodecylsulphate or urea gives a single band, indicating that the enzyme is composed of four subunits similar in their molecular weight and net charge. Cyanogen bromide cleavage and tryptic digestion of the enzyme yield the number of peptides expected for identical subunites from the amino acid composition analysis. 3. The purified phosphoglyceromutase preparation has bisphosphoglyceromutase activity synthesizing 2,3-bisphosphoglycerate from 1,3-bisphosphoglycerate and 3-phosphoglycerate. It has been reported that yeast phosphoglyceromutase catalyzes the hydrolysis of 2,3-bisphosphoglycerate at the same active site which catalyzes the phosphoglyceromutase reaction [Sasaki, R. et al (1971) Biochim. Biophys, Acta, 227, 584-594, 595-607]. Immunological studies and chemical modification experiments indicate that bisphosphoglyceromutase activity also is due to the phosphoglyceromutase protein and involves amino groups which have been shown to be essential for the other two activities.

Amino Acids↗
PubMed1976

Premature induction of amylase in pancreas and parotid gland of growing rats by dexamethasone.

Studies were made on changes in the contents of alpha-amylase (EC 3.2.1.1) in the pancreas and parotid gland of rats during postnatal development, on the premature induction of this enzyme by hormones and on the existence of specific glucocorticoid receptors in these tissues. The amylase content in the pancreas increased from the 9th day after birth and reached the adult level on the 28th day, its content in the parotid gland increased rapidly from the 16th to the 28th day after birth and then rose more gradually to the adult level. Injection of dexamethasone into rats 6--8 days after birth induced increase in the amylase of the pancreas but not the parotid gland. However, injection of dexamethasone into weanling rats 21--23 days after birth resulted in precocious induction of amylase in both tissues. Specific glucocorticoid receptors were detectable in the parotid gland of rats from 6 days after birth but were almost undetectable in the pancreas until adolescence.

Aging↗
PubMed1976

Aging and hydroxproline content in human heart muscle.

Hydroxproline content was chemically determined in 45 human hearts obtained at autopsy, in order to know possible correlations between aging and hydroxyproline content in the heart muscle. There were no significant differences in the mean total hydroxyproline content between the epicardium and the endocardium, between left and right ventricles, nor between young, middle and old age groups. The hydroxyproline content in NaCl-soluble fraction decreased, and that in TCA-soluble fraction and in residue fraction increased with age. There were significant differences in the mean hydroxyproline content in NaCl-soluble fraction between middle and old age groups, and in residue fraction between young and old age groups in the endocardium of the left ventricle. Accordingly, the ratio of the content in NaCl-soluble fraction to that in TCA-soluble fraction decreases with age. This tendency was more evident in the epicardium than in the endocardium on the left ventricle. These results indicate that total hydroxyproline content per 1 mg of lyophilized material does not show any quantitative changes, but does show qualitative changes with age.

Adolescent↗
PubMed1976

Ischemic colitis.

Although several hundred cases of ischemic colitis have been reported from western countries, no case has been reported in our country. Ischemic colitis is a well established entity. Clinicopathological manifestations, disgnosis, treatment and prognosis of the disease are well known. A majority of reported cases were not particularly unusual. Two cases, of which one showed an unusually long lasting acute episode but good prognosis, and the other presented a diagnostic problem and was found to have a fibrous stricture due to ischemic colitis in the sigmoid colon at surgery, were described and discussed in relation to their symptoms, diagnosis and prognosis.

Aged↗
PubMed1975

Comparative studies on electrophoretic mobility and immunogenicity of pancreatic and parotid amylases of rat.

1. The alpha-amylases (1,4-alpha-D-glucan glucanohydrolase, EC 3.2.1.1) of rat serum, urine, pancreas, parotid gland and liver were separated by electrophoresis on a cellulose acetate membrane. They were found to be of three different types: a parotid gland type, a pancreatic type and a liver type. Rat serum and urine contained parotid type amylase only. 2. Antisera were prepared in rabbits against purified rat pancreatic amylase and parotid amylase. In addition to strong reactions between pancreatic amylase and its antiserum and between parotid amylase and its antiserum, a weak cross-reaction was observed between parotid amylase and anti-pancreatic amylaseserum. Anti-parotid-amylase serum gave an immunoprecipitation line with rat serum and urine, but anti-pancreatic-amylase serum did not, indicating that the amylases in serum and urine originate from parotid amylase.

Amylases↗
PubMed1975

Purification of bisphosphoglyceromutase, 2,3-bisphosphoglycerate phosphatase and phosphoglyceromutase from human erthrocytes. Three enzyme activities in one protein.

Bisphosphoglyceromutase, 2,3-bisphosphoglycerate phosphatase and phosphoglyceromutase have been purified from human red cells. Three enzymes were co-purified throughout all purification steps. Three fractions (peaks I, II and III) which were chromatographically separable and had three activities in different ratios were obtained. Peak III which contained the main bisphosphoglyceromutase and 2,3-bisphosphoglycerate phosphatase activities was purified to homogeneity by electrophoretic and ultracentrifugal analyses. The homogeneous preparation had the phosphoglyceromutase activity. The three activities were lost at the same rate during thermal inactivation. Thus, bisphosphoglyceromutase and 2,3-bisphosphoglycerate phosphatase activities, which are responsible for 2,3-bisphosphoglycerate metabolism in red cells, are displayed by the same enzyme protein which has phosphoglyceromutase activity. Peaks I and II were rich in the phosphoglyceromutase activity. Both peaks showed bisphosphoglyceromutase and 2,3-bisphosphoglycerate phosphatase activities, although these two activities were much smaller than those of peak III. Some of the enzymic properties of peak III are described. Comparative studies on three peaks showed that the phosphoglyceromutase of peak III differed from that of peaks I and II in the kinetic property and thermostability.

Chromatography↗
PubMed1975

Histometrical estimation of scar tissue in hypertrophied human heart muscle.

Histometrical estimation of scar tissue was made on 28 hypertrophied human hearts obtained at autopsy in order to know the significance of scar tissue in the process of cardiac hypertrophy and in the development of cardiac failure. Estimation was made on histological specimens of the anterior wall of the left ventricle and the posteromedial papillary muscle, according to Chalkley's point counting method, and the amount of scar tissue was expressed by percentages. The mean percentages were 4.6, 8.5 and 18.3 in the epicardial, endocardial part of the left ventricle, and the papillary muscle. There were very significant differences between these 3 mean percentages. There was a very significant correlation between the percentages of scar tissue in the endocardial part of the left ventricle and heart weight. There were no definite correlations between the percentages of scar tissue in the epicardial part or in the papillary muscle and heart weight. From these results, possible causes of scar formation and significance of scar tissue to the development of cardiac failure were discussed.

Adult↗
PubMed1975

Aging and scar tissue in human heart muscle.

Histometrical estimation of scar tissue was made on 30 human hearts obtained at autopsy in order to know possible correlations between aging and scar tissue in the heart muscle. Estimation was made on histological specimens of the anterior wall of the left ventricle and the posteromedial papillary muscle, according to Chalkley's point counting method, and the amount of scar tissue was expressed in percentage. The mean percentages were 3.11, 5.26 and 9.24 in the epicardial, endocardial parts of the left ventricle and the papillary muscle, respectively. There were very significant differences between these 3 mean percentages. There were very significant correlations between the percentages of scar tissue in these 3 parts and ages. From these results, it is concluded that the scar formation increases in the heart muscle with aging.

Adolescent↗