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S Fujii

Publications and source records attributed to S Fujii.

At least 613 records · Page 34Linked to original sources
PubMed1989

Smooth muscle differentiation at endometrio-myometrial junction. An ultrastructural study.

To determine whether myometrial smooth muscle is newly produced at the endometrio-myometrial junction (EMJ) of the adult uterus, we examined the ultrastructure of mesenchymal components at this site during the menstrual cycle and during early pregnancy. Cells having some features of smooth muscle were found among the usual endometrial stromal cells in every specimen examined. In the follicular phase of the menstrual cycle, such cells resembled myofibroblasts, but in the luteal phase and during early pregnancy, they had more distinct cytoplasmic filaments with dense bodies and dense plaques, and other fairly well developed characteristics of smooth muscle. The identification of smooth muscle-like cells at the EMJ in the adult uterus and the finding that their morphology changes into cells having many of the characteristics of smooth muscle cells during the luteal phase and early pregnancy, suggests that smooth muscle differentiation possibly occurs from multi-potential mesenchymal cells in the endometrial stroma.

Adult↗
PubMed1989

Immunohistochemical localization and tissue levels of tumor-associated glycoproteins CA 125 and CA 19-9 in the decidua and fetal membranes at various gestational ages.

To investigate the sources and biologic significance of CA 125 and CA 19-9 in amniotic fluid, immunohistochemical and biochemical localization of these tumor-associated glycoproteins in the decidua and fetal membranes was studied. Immunohistochemically, CA 125 and CA 19-9 were localized in the cytoplasm of decidua cells and amnion epithelial cells but not in the chorion and placental tissue. Biochemically, the 12,000 X g supernatant fractions of decidua and amnion tissues contained relatively large amounts of CA 125 and CA 19-9, 73% to 96% of which was present in the cytosolic fractions of these tissues. The CA 125 levels in the amniotic fluid decreased, whereas those of CA 19-9 increased with gestation, which correlated well with the respective levels in amnion tissues. These findings suggest that amnion cells produce and secrete these glycoproteins into the amniotic cavity. However, it is possible that the decidua also secretes CA 125 into the amniotic cavity through the chorion and amnion such as in the case of prolactin.

Amniotic Fluid↗
PubMed1989

CA 125 in the epithelium closely related to the embryonic ectoderm: the periderm and the amnion.

The amnion is believed to be derived from either cytotrophoblastic cells or embryonic ectoderm. However, it produces and secretes CA 125, which is considered a differentiation antigen of fetal coelomic epithelium derived from the mesoderm of germ cells. To verify this, the immunohistochemical localization of CA 125 in human fetal tissues (between 7 and 23 weeks of gestation) derived from the ectoderm, endoderm, or mesoderm, and in the fetal membranes and placenta was studied. Among the mesoderm-derived tissues, only the fetal coelomic epithelium-related tissues were positive for anti-CA 125 from 15 weeks of gestation. The endoderm-derived tissues did not react with anti-CA 125. However, among the ectoderm-derived tissues, only the periderm reacted with anti-CA 125 from 7 weeks until it sloughed from the stratum intermedium by 23 weeks of gestation. Among the fetal membranes and placenta, only the amnion reacted with anti-CA 125 from 9 weeks to term. These findings indicate that the amnion and the periderm, both of which constitute the epithelia covering the amniotic cavity, in addition to the fetal coelomic epithelium-related tissues, produce CA 125.

Amnion↗
PubMed1989

Microsomal glutathione-dependent protection against lipid peroxidation acts through a factor other than glutathione peroxidase and glutathione S-transferase in rat liver.

Ascorbate-Fe3+-induced and NADPH-induced lipid peroxidation of rat liver microsomes were inhibited by glutathione (GSH). This inhibition was due to microsomal GSH-dependent factor. This factor was heat labile, and storage of microsomes at 4 degrees C for 1 week diminished the activity. GSH could not be substituted by other sulfhydryl compounds tested. Deoxycholate (1 mM) and bromosulfophthalein (0.1 mM) inhibited GSH-dependent protection but did not inhibit microsomal GSH peroxidase activity. Iodoacetate (10 mM) inhibited GSH-dependent protection but did not inhibit microsomal GSH S-transferase. N-Ethylmaleimide (0.1 mM) and oxidized glutathione (10 mM) inhibited GSH-dependent protection but activated microsomal GSH S-transferase activity. These results indicate the existence of a heat-labile, microsomal GSH-dependent protective factor against lipid peroxidation that acts through a factor other than GSH-peroxidase and GSH S-transferase.

Animals↗
PubMed1989

Closed and continuous algae cultivation system for food production and gas exchange in CELSS.

In CELSS (Controlled Ecological Life Support System), utilization of photosynthetic algae is an effective means for obtaining food and oxygen at the same time. We have chosen Spirulina, a blue-green alga, and have studied possibilities of algae utilization. We have developed an advanced algae cultivation system, which is able to produce algae continuously in a closed condition. Major features of the new system are as follows. (1) In order to maintain homogeneous culture conditions, the cultivator was designed so as to cause a swirl on medium circulation. (2) Oxygen gas separation and carbon dioxide supply are conducted by a newly designed membrane module. (3) Algae mass and medium are separated by a specially designed harvester. (4) Cultivation conditions, such as pH, temperature, algae growth rate, light intensity and quantity of generated oxygen gas are controlled by a computer system and the data are automatically recorded. This equipment is a primary model for ground experiments in order to obtain some design data for space use. A feasibility of algae cultivation in a closed condition is discussed on the basis of data obtained by use of this new system.

Biomass↗
PubMed1989

Mechanism and clinical significance of elevated CA 125 levels in the sera of pregnant women.

To clarify the mechanism of CA 125 elevation in maternal sera, serum levels of CA 125 and CA 19-9 were measured in 122 apparently healthy pregnant women (fifth to fortieth week of gestation) and 50 postpartum women (26 term deliveries and 24 second-trimester induced abortions). Serum levels of CA 125 showed an initial increase by the tenth week and then decreased to less than 35 U/ml, remaining below this level until delivery. However, within 1 hour after term delivery or second-trimester induced abortion, the CA 125 levels showed a second increase and decreased rapidly thereafter. In contrast, serum levels of CA 19-9 did not change significantly during these periods. Combined with our previous finding that the decidua contains abundant CA 125 but little CA 19-9, these results indicate that the elevated CA 125 levels in maternal sera originate from the decidual cells affected by chorionic invasion or the placental separation.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1989

Mitotic activity in uterine leiomyomas during the menstrual cycle.

To investigate the role of the menstrual cycle in the growth of uterine leiomyomas, the mitotic count per 100 high-power fields and the relation of this to the patient's age (30 to 54 years) were examined in tissue sections of leiomyomas from 181 surgically removed myomatous uteri. The mean mitotic count in the secretory phase (12.7 per 100 high-power fields) was significantly higher than that of the proliferative phase (3.8 per 100 high-power fields) (p less than 0.01) or menses (8.3 per 100 high-power fields) (p less than 0.05). We found the highest mitotic count (54 per 100 high-power fields) in a leiomyoma at the early secretory phase. In the secretory phase, the younger age group exhibited a significantly higher mitotic count than the older group. Increased mitotic activity in leiomyomas under the hormonal milieu of the secretory phase of the menstrual cycle suggests that the growth of these tumors is affected by progesterone level. In addition, this study defined the range of mitotic counts occurring in the tissue sections of typical leiomyomas during the menstrual cycle.

Adult↗
PubMed1989

Role of Ca2+ in the substrate binding and catalytic functions of snake venom phospholipases A2.

Phospholipases A2 are classified into two groups, I and II, according to differences in the polypeptide-chain length and the intramolecular-disulfide bondings. The effects of Ca2+ on the kinetic parameters for the hydrolysis of monodispersed and micellar phosphatidylcholines, catalyzed by a cobra (Naja naja atra) enzyme (Group I) and by mamushi (Agkistrodon halys blomhoffii) and habu (Trimeresurus flavoviridis) enzymes (Group II), were studied by the pH-statassay method at 25 degrees C, pH 8.0-8.2, and ionic strength 0.1-0.2. The results were compared with those reported for the other Group I and II enzymes. The Ca2+ binding was clearly shown to be essential for the catalysis of all the phospholipases A2. However, the substrate binding to Group I enzymes was found to be independent of the Ca2+ binding. On the other hand, the substrate binding to Group II enzymes was facilitated more than 10 times by the binding of Ca2+ to the enzymes. This was interpreted in terms of conformation changes of the peptide loop of residues 26 to 44 accompanying the Ca2+ binding. The latter result, but not the former, seems compatible with the hypothesis for interpreting the catalytic mechanism of phospholipases A2 that an intermediate complex should be stabilized by the coordination of the bound Ca2+ ion with the phosphoryl group and the carbonyl oxygen atom of the ester bond at the sn-2 position of the bound substrate molecule [Verheij et al. (1980) Biochemistry 19, 743-750 and (1981) Rev. Physiol. Biochem. Pharmacol. 91, 91-203]. According to the similarity in the primary and tertiary structures of the active sites of both types of enzymes [Renetseder et al. (1985) J. Biol. Chem. 260, 11627-11634], it is supposed that similar intermediate complexes may occur even for Group I enzymes, at least in the transition state of the productive complexes.

Animals↗
PubMed1989

Microsomal phosphatidate phosphatase in maturing safflower seeds.

An assay system comprising sodium phosphatidate, phosphatidylcholine, and bovine serum albumin has been developed for the reproducible determination of phosphatidate phosphatase activity in maturing seeds of safflower (Carthamus tinctorius L.). The activity was detected in both membrane and soluble fractions, and the microsomal phosphatidate phosphatase was characterized. The optimum pH for Pi release was 6.7, and the activity depended on the concentration of Mg(2+). Phosphatidylcholine and bovine serum albumin stimulated the phosphatase reaction. This phosphatase was highly specific for phosphatidate; lysophosphatidate, and water-soluble phosphate esters did not serve as substrate. The specific activity was approximately 20 nanomoles per minute per milligram of protein, which was close to that of glycerol-phosphate acyltransferase and higher than that of diacylglycerol acyltransferase. Furthermore, the activity per seed was enough to account for the rate of triacylglycerol accumulation in vivo. The step of diacylglycerol formation by phosphatidate phosphatase does not appear to be rate-limiting for triacylglycerol synthesis during seed maturation.

Journal Article↗
PubMed1989

Pharmacokinetic modulation of plasma 5-fluorouracil concentrations to potentiate the antitumor activity of continuous venous infusion of 5-fluorouracil.

Methods for pharmacokinetic modulation of the plasma 5-fluorouracil (5-FU) level to increase antitumor activity during continuous venous infusion (CVI) of low doses of 5-FU were examined in Yoshida sarcoma-bearing rats. These methods were additional infusion of 5-FU for a short period (4 h) or oral administration of UFT or Tegafur during long-term CVI of 5-FU that alone gave a plasma 5-FU level of about 50 ng/ml. The antitumor effect on Yoshida sarcoma was markedly potentiated when an additive dose of 5-FU combined with 3-cyano-2,6-dihydroxypyridine (CNDP), a potent inhibitor of 5-FU degradation, giving a plasma level of about 500 ng/ml, was infused for 4 h. A similar increase in the antitumor effect was observed with oral administration of a conventional dose of UFT during CVI of 5-FU without CNDP, giving a plasma level of 30 to 60 ng/ml. These results suggest that the antitumor effect of CVI of 5-FU can be potentiated by pharmacokinetic modulation of the 5-FU concentration in the blood.

Animals↗
PubMed1989

Effects of the plasma concentration of 5-fluorouracil and the duration of continuous venous infusion of 5-fluorouracil with an inhibitor of 5-fluorouracil degradation on Yoshida sarcomas in rats.

The correlations of the 5-fluorouracil (5-FU) level in the plasma and the duration of continuous 5-FU infusion with the antitumor activity of 5-FU on Yoshida sarcomas in rats were examined. The circadian variation in the plasma level of 5-FU during continuous infusion was prevented by treatment with 3-cyano-2,6-dihydroxypyridine (CNDP), which strongly inhibits 5-FU degradation. On continuous venous infusion of 2 to 30 mg/kg of 5-FU over 24 h with CNDP at a molar ratio of 1:10 into normal rats, the 5-FU level in the blood was linearly proportional to the dose of 5-FU. The optimum schedule for antitumor activity on Yoshida sarcomas in rats was found to be infusion of 5-FU at 5 mg/kg over 24 h for 6 consecutive days, which gave a plasma 5-FU level of 176 ng/ml. Continuous infusion of 5-FU to give a plasma level of 300 ng/ml for 6 consecutive days from day 5 after implantation of tumor cells, when the tumors weighed about 1.0 g, resulted in complete regression of the tumors in all rats.

Animals↗
PubMed1989

Antitumor activity of BOF-A2, a new 5-fluorouracil derivative.

A compound containing both CNDP (3-cyano-2,6-dihydroxypyridine), an inhibitor of 5-fluorouracil (5-FU) degradation, and EM-FU (1-ethoxymethyl-5-fluorouracil), a masked form of 5-FU, was synthesized and named BOF-A2 (3-[3-(6-benzoyloxy-3-cyano-2-pyridyloxycarbonyl)benzoyl]-1-ethoxy methyl-5- fluorouracil). The antitumor activity of BOF-A2 was investigated in sarcoma-180-bearing mice and Yoshida sarcoma-bearing rats. The ED50 (the dose for 50% inhibition) values of BOF-A2 were 25 mg/kg against sarcoma-180 and 15 mg/kg against Yoshida sarcoma. In vitro studies showed that BOF-A2 was rapidly degraded to EM-FU and CNDP in homogenates of the liver and small intestine of mice and rats, and in sera of mice, rats and human, and the conversion of EM-FU to 5-FU occurred only in the microsomal fraction of rat liver in the presence of NADPH. After oral administration of BOF-A2 at 15 mg/kg to Yoshida sarcoma-bearing rats, BOF-A2 was hydrolyzed to EM-FU, CNDP and 5-FU, and their maximum concentrations in the blood were 2000 ng/ml, 300 ng/ml and 40 ng/ml, respectively. Moreover when BOF-A2 was given at the same dose to tumor-bearing mice and rats, the 5-FU levels in the tumor tissue increased much more than those in the blood and persisted for more than 8 h, whereas those in the blood decreased more rapidly. This accumulation and maintenance of a high level of 5-FU in the tumor tissue are concluded to be related to the high antitumor activity of BOF-A2.

Administration, Oral↗
PubMed1989

Stimulation of cyclic AMP production in FRTL-5 thyroid cells by crude immunoglobulin fractions of serum from pregnant women.

In an assay for thyroid-stimulating antibodies, in which FRTL-5 thyroid cells were incubated with crude immunoglobulin (Ig) fractions precipitated from serum with 15% polyethylene glycol, significant increase in cAMP production was elicited by the samples from 25 (35.7%) out of 70 pregnant women. The highest value was 529.5%. There was a close correlation between thyroid stimulating activities and serum hCG concentrations (r = 0.708, P less than 0.001). When 125I-hCG was added to serum from pregnant women, about 20% of the radioactivity was incorporated into the Ig fractions. hCG preparations within a range of concentrations of 30-300 IU/m elicited 2.3-16.5 times increase in cAMP in a dose-dependent manner. Nine pregnant women with serum TSH concentrations less than the lower limit of the normal range (less than 0.25 mU/l) displayed significantly higher values for both thyroid stimulating activities and serum hCG concentrations (P less than 0.001, respectively) compared with those who had normal TSH levels in serum. These data suggest that hCG or its variant may stimulate the thyroid sufficiently to suppress secretion of TSH from the pituitary in some pregnant women.

Adult↗
PubMed1989

Radioimmunoassay for erythrocyte acidic GSH S-transferase.

We have developed a RIA for erythrocyte acid glutathione S-transferase (GST), which is immunologically identical to major GSTs from other blood cell components, and measured its serum concentrations in various hematological disorders. In some patients with paroxysmal nocturnal hemoglobinuria, chronic myelomonocytic leukemia, chronic myelocytic leukemia, polycythemia vera and myelofibrosis, the concentrations were high. Very high levels were found in 2 of 3 patients with acute lymphocytic leukemia, while acute myelocytic leukemia exhibited a modest increment. No or little increase was seen in aplastic anemia and myelodysplastic syndrome except chronic myelomonocytic leukemia. It is suggested that the measurement of serum acidic GST may be of use as a clinical marker of increased destruction and/or overproduction of blood cells.

Erythrocytes↗
PubMed1989

Dependence of fibrinolytic activity on the concentration of free rather than total tissue-type plasminogen activator in plasma after pharmacologic administration.

To identify factors responsible for the decline of plasma tissue-type plasminogen activator (t-PA)-specific activity that we have observed after infusions of the activator and to define the potential usefulness of selected variants of t-PA in obviating them in patients with infarction, serial plasma samples from patients (n = 4) and rabbits (n = 15) given t-PA were assayed for total t-PA antigen, t-PA activity, and free as opposed to type-1 plasminogen activator inhibitor (PAI-1)--complexed t-PA. In patients, attenuation of t-PA specific activity after infusions was evident with concentrations of total t-PA antigen that were as much as sevenfold greater than pretreatment values (62 compared with 9 ng/ml). Attenuation of t-PA activity corresponded with the disappearance of free t-PA from plasma and was associated with persistence of complexes of t-PA with PAI-1. In normal rabbits (n = 4) given wild-type t-PA by bolus injection, PAI-1 activity was 4 +/- 1 arbitrary units/ml. Attenuation of t-PA activity was not evident until 60 minutes after injection at a time when total plasma t-PA antigen concentration was as low as 13 +/- 8 ng/ml. Under these conditions, plasma t-PA was composed predominantly of free t-PA. In rabbits (n = 5) given lipopolysaccharide to increase plasma PAI-1 activity to 193 +/- 84 arbitrary units/ml, the specific activity of t-PA was attenuated as early as 15 minutes after injection at a time when total t-PA antigen concentration was as high as 164 +/- 79 ng/ml. As was the case with samples from patients, attenuation was associated with the disappearance of free t-PA and the persistence of complexes of t-PA with PAI-1. A genetically engineered variant of t-PA with comparable specific activity and a comparable rate constant of association with PAI-1 but designed to persist in the circulation manifested prolonged clearance from plasma of normal rabbits (n = 3) (t1/2 = 24.6 +/- 1.6 minutes compared with an alpha phase t1/2 of 1.9 minutes for wild-type t-PA). The variant lacked the epidermal growth factor and kringle one domains and contained a duplicated kringle two domain.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1989

[Deoxyribonucleic acid sequence effects on molecular structure].

The deoxyribonucleic acid (DNA) duplex shows polymorphism depending on the base sequence and the environment. The base sequence dependent variations in conformational properties of the synthesized oligonucleotides are studied by X-ray analysis and several physico-chemical techniques. The possible structures in solution were proposed by molecular dynamics (MD) simulation. 1) The several oligonucleotides which include the adenine or adenine-thiamine tract, have unique conformational characteristics with the base sequence dependent property. The junction-model structure for DNA bending was proposed by the combined method of nuclear magnetic resonance (NMR) observations and MD calculation. 2) The two different hydrogen bonding schemes of inosine-adenine base-pairing, anti/anti and anti/syn forms, are adopted in B-DNA structure. The preference of these forms depends on the base sequence. The MD calculation could offer the models consistent with NMR evidence. 3) Oligonucleotides containing cyclonucleosides with a high-anti (intermediate between anti and syn) glycosidic conformation adopt left-handed double-helical structures. A suitable model of this left-handed duplex was proposed by calculation with energy minimization.

Adenine↗