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Biomedical subjects

H Sakura

Publications and source records attributed to H Sakura.

At least 73 records · Page 4Linked to original sources
PubMed1985

Large glucagon-like immunoreactivity in a primary ovarian carcinoid.

A primary ovarian carcinoid composed of both trabecular and strumal types was studied by histochemical, immunocytochemical, and biochemical techniques. High contents of glucagon, secretin, and calcitonin were demonstrated in the tumor homogenate. All of the tumor cells, irrespective of histologic type, showed properties of argyrophilia and neurosecretory granules on electron microscopy. Glucagon-producing cells were positive in trabecular carcinoid by immunoperoxidase techniques. Bio-Gel P10 gel filtration showed that the molecular weight of major immunoreactive glucagon in tumor was 20,000. It migrated faster than true glucagon after polyacrylamide gel electrophoresis. No clinical symptoms of glucagonoma developed.

Adult↗
PubMed1985

Oxytocinase-like enzyme in an ovarian dysgerminoma: a placenta-specific protein.

Aminopeptidase from dysgerminoma was purified and characterized using L-leucine-beta-naphthylamide as substrate. The enzyme was resistant to puromycin, methionine, amastatin, bastatin, and EDTA, and it was heat labile at 60 degrees C. The enzyme showed the same electrophoretic mobility as pregnant-patient serum oxytocinase CAP1 on polyacrylamide gel electrophoresis. Km value against S-benzylcysteine-p-nitroanilide was 4.2 X 10(-4) M. Oxytocin and vasopressin competitively inhibited the enzyme activity. Molecular weight of the enzyme was estimated to be 80,000 by Sephadex G-200 column chromatography. These results suggest that aminopeptidase from dysgerminoma is an oxytocinase-like enzyme, a placenta-specific protein.

Adult↗
PubMed1985

[The significance of serum leucine aminopeptidase (P-LAP) determination in the gynecological malignancies].

We determined Placental-Leucine Aminopeptidase (P-LAP) activity, one of the oncodevelopmental antigens, in sera and in tissues of patients with gynecological cancers. The incidence of P-LAP activity and clinical usefulness of the determination of serum P-LAP activity were studied. The mean level in healthy non-pregnant sera used as controls was 6.0 +/- 2.4mg/dl/h. The mean level of P-LAP activity in patients with benign tumors such as myoma uteri and benign ovarian tumor did not increase in comparison with the controls. The mean level of P-LAP activity in patients with malignant tumor increased with advancing stages, and especially in advanced cervical and ovarian cancer, serum P-LAP levels were significantly higher than in the controls. Serum P-LAP activity correlated with the serum ferritin concentration (r=0.613), but not with the serum alpha-fetoprotein and serum carcinoembryonic antigen concentration. Serial measurements of serum P-LAP activities in patients with gynecological cancer showed that serum P-LAP activity might reflect the progress of cervical and ovarian cancer. Tissue P-LAP activities in 29 ovarian cancers were compared with those in normal tissues. Tissue P-LAP activities in 26 cases out of 29 increased to twice as high as the mean activities in 10 normal ovaries. Our present results suggest the possibility of using P-LAP activity as one of tumor markers for gynecological malignant tumors.

Adult↗
PubMed1983

Changes in plasma renin activity (PRA), angiotensin I and placental leucine aminopeptidase (P-LAP) activity during normal pregnancy.

Plasma renin activity (PRA) and relative changes in angiotensin I compared with non-pregnant women were determined by radioimmunoassay (RIA) at different stages of normal gestation. Their levels showed increases in the early and late stages, and decreases at the period of 25 to 28 weeks of pregnancy in the middle stage, although their levels were higher than those in non-pregnant women throughout pregnancy. The increase in angiotensin I was less striking than that of PRA. Placental leucine aminopeptidase (P-LAP) activity increased progressively with advancing gestation, reaching the highest value at the 38th week of pregnancy. Simultaneous estimations of changes in angiotensin I and placental leucine aminopeptidase (P-LAP) were performed longitudinally in 12 normal pregnant women. The significance of the increase in P-LAP activity and the relationships among PRA, angiotensin I and P-LAP during normal pregnancy are discussed.

Angiotensin I↗
PubMed1983

Kinetic properties of placental aminopeptidase A: N-terminal degradation of angiotensin II.

Purified placental aminopeptidase A cleaved N-terminal aspartic acid of Angiotensin II, and it was inhibited by amastatin. Amastatin and various angiotensin analogs having N-terminal dicarboxylic acid were potent inhibitors of the enzyme. Kinetic analysis indicated that amastatin, angiotensin II, the N-terminal tripeptide of angiotensin II, and aspartic acid were competitive inhibitors, with Ki values 1.25 X 10(-7) M, 2.40 X 10(-5) M, 2.67 X 10(-4) M, and 1.2 X 10(-3)M respectively. The enzyme was also inhibited by transition metals, such as Zn2+, Cu2+, Cd2+ and Ni2+. Serum aminopeptidase A activity progressively increased during the course of normal pregnancy.

Amino Acids↗
PubMed1983

[Gynecological cancer and ferritin--a study on the carcinofetoplacental ferritin].

Serum and tissue ferritins were quantitated by a radioimmunoassay kit (SPAC KIT, Daiichi Radioisotope Lab.) and a diagnostic implication of serum ferritins in patients with gynecological diseases was evaluated. In order to investigate the potential use of tumor marker as a feto-placental antigen (protein), ferritin from ovarian cancer was compared with ferritins from normal adult and feto-placental organs. Serum ferritin levels were significantly higher (p less than 0.01) in patients with ovarian adenocarcinoma, Krukenberg's tumor, cervical squamous cell carcinoma and other malignant diseases than in normal women. Among adult organs the kidney and spleen showed the highest and the heart the lowest ferritin content. The ferritin contents of the kidney and spleen were 78.4 micrograms and 76.2 micrograms/g wet weight, respectively and that of the heart was 5.7 micrograms/g wet weight. The ferritin contents of other adult organs ranged from 10 to 25 micrograms/g wet weight. On the other hand the placenta showed the highest and the heart and stomach the lowest ferritin content among feto-placental organs. The ferritin content of the placenta was 7 micrograms/g wet weight. The ferritin contents of other fetal organs were only half as in the placenta. The ferritin contents of ovarian cancers ranged 6 to 8 micrograms/g wet weight and was almost identical to that of the placenta.

Adenocarcinoma↗
PubMed1982

Simultaneous determinations of plasma oxytocin and serum placental leucine aminopeptidase (P-LAP) during late pregnancy.

1. Plasma oxytocin concentrations were measured by radioimmunoassay in 231 normal pregnant patients. The mean level of the maternal plasma oxytocin increases gradually with advancing pregnancy, culminating in a marked increase during the last two months. 2. Serum placental leucine aminopeptidase (P-LAP) activities and oxytocinase were measured serially in 78 obstetrically normal pregnant patients during late pregnancy. The daily mean P-LAP activity rises progressively during late pregnancy, reaching a relatively high level at 11 days prior to the onset of labor, then fluctuates slightly until the onset of labor. 3. Simultaneous serial measurements of plasma oxytocin levels and serum P-LAP activities in 9 normal pregnant women during late pregnancy show that the onset of labor is preceded by either an increase in the oxytocin level or a decrease in the P-LAP activity.

Adult↗
PubMed1982

Simultaneous determinations of total cortisol and progesterone by radioimmunoassay during late pregnancy.

Total cortisol and progesterone in the maternal peripheral sera were determined by radioimmunoassay. Total cortisol was measured in 196 sera, and progesterone in 203 sera obtained randomly throughout pregnancy. And serial estimations of both steroid hormone levels were also made simultaneously in 6 normal pregnant women during late pregnancy, labour and puerperium. Total cortisol and progesterone increased with the advance of gestation. During the last few weeks preceding labour total cortisol increased further, whereas progesterone decreased. After the onset of labour a rising tendency in total cortisol levels and a falling tendency in those of progesterone were also observed, but at puerperium both hormones decreased rapidly to non-pregnant level in the 6 pregnant women.

Female↗
PubMed1979

A comparison of angiotensinase and placental leucine aminopeptidase during normal pregnancy.

1. Serum leucine aminopeptidase activity measured by its action on hydrolysis of L-leucyl-beta-naphthylamide was increased progressively as pregnancy advanced. Angiotensinase activity determined by bioasaay showed parallel increase during normal pregnancy. 2. The effects of heat treatment and L-methionine on the activity of angiotensinase were compared with those on leucine aminopeptidase activity in pregnancy serum.

Endopeptidases↗
PubMed1978

Formation and characterization of antibody against 2'-(5"-phosphoribosyl)-5' AMP, the monomer form of poly(adenosine diphosphate ribose).

Specific antibody against 2'-(5"-phosphoribosyl)-5'AMP (PR-AMP), a monomer of poly(adenosine diphosphate ribose) (poly(ADP-Rib)), was produced by immunizing a rabbit with PR-AMP coupled to bovine serum albumin (BSA). Antibody against PR-AMP was purified 53-fold from serum by (NH4) 2SO4 precipitation, and BSA-Sepharose 4B, DEAE-cellulose and (PR-AMP)-BSA-Sepharose 4B column chromatographies. Inhibition experiments show that the adenine ring, 5'-phosphate residue and ribose-ribose bond of PR-AMP were essential for the antigenic determinant of PR-AMP. Anti PR-AMP antibody bound, not only with PR-AMP, but also with poly(ADP-Rib) of various chain lengths, while anti poly(ADP-Rib) antibody bound with poly(ADP-Rib) but not with PR-AMP.

Adenosine Monophosphate↗
PubMed1978

Demonstration of high molecular weight poly (adenosine diphosphate ribose).

An electrophoretic system was established that resolves poly(adenosine diphosphate ribose), enzymatically synthesized polymer from NAD+, by size difference of one residue on polyacrylamide gel. The existence of a polymer of at least 65 residues was demonstrated by band counting in this system. The polymer showed a heterogeneous size distribution on the electrophoregram, and the molecular weight of the largest polymer was deduced to be more than 4.5 X 10(5) daltons. The discrepancy between the size, estimated by electrophoresis, and the chain length, determined by the ratio of total radioactivity to that derived from the terminus, suggests that the polymer has a branched structure.

Animals↗
PubMed1977

A 13C NMR study of poly(adenosine diphosphate ribose) and its monomers: evidence of alpha-(1'' leads to 2') ribofuranosy1 ribofuranoside risidue.

The 13C NMR spectra of poly(adenosine diphosphate ribose), ribosyl adenosine 5', 5''-bis(phosphate) and related compounds were analyzed. The structure of the ribose-ribose linkage was determined as alpha-(1'' leads to 2')ribofuranosyl ribofuranoside, from the 13C chemical shifts of methyl-alpha- and methyl-beta-D-ribofuranosides, and from the downfield displacements of 13C NMR signals by glycosidic bond formation.

Adenosine Diphosphate Sugars↗
PubMed1977

Natural occurence of a biopolymer, poly (adenosine diphosphate ribose).

Evidence for the natural occurrence of poly(adenosine diphosphate ribose) in vivo was obtained using a sensitive radioimmunoassay and poly(adenosine diphosphate ribose) glycohydrolase, which specifically hydrolyzes poly(adenosine diphosphate ribose). Calf thymus, liver, kidney, brain, pancreas and spleen contained poly(adenosine diphosphate ribose). Naturally occurring poly(adenosine diphosphate ribose) in calf thymus is composed of molecules of various chain lengths, like that synthesized by an in vitro system. Calf thymus was estimated to contain about 0.02 microgram/mg DNA of poly(adenosine diphosphate ribose).

Animals↗