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S Ichii

Publications and source records attributed to S Ichii.

At least 55 records · Page 3Linked to original sources
PubMed1991

Isolation and characterization of cDNA clones for castration-induced mRNAs in the rat ventral prostate.

To identify gene products involved in castration-induced involution of the rat ventral prostate, we constructed a subtraction cDNA library of the ventral prostate from rats castrated for 48 h. The library was screened with subtracted cDNA probes enriched for sequences with a low copy number expressed in intact or castrated rats. As a result of differential screening, 48 cDNA clones representing 10 different induced mRNAs were isolated. The time course of these mRNA inductions after castration was examined. Within the first 24 h after castration, the level of mRNAs for these cDNA clones was significantly increased and it reached its peak by 48-72 h after castration. Although mRNAs for these cDNA clones were expressed in various tissues from intact rats, an increase in mRNA as a response to castration was observed only in the ventral prostate. Partial sequence analyses of the 10 cDNA clones indicate that three cDNA clones represent rat glutathione S-transferase Yb-1, Yb-2 and Yb-3 subunit mRNA sequences, but for others respective homologues could not be found in a search of the GenBank database (release 67).

Animals↗
PubMed1990

Epidermal growth factor receptor mRNA in livers from newborn, adult and partially hepatectomized rats.

Epidermal growth factor (EGF) receptor mRNA expression in livers of newborn, adult control and partially hepatectomized rats 1 and 3 days post-operation was examined by Northern blot analysis. A human EGF receptor cDNA (P 64-1, Ullrich et al., 1984) was hybridized to RNA species of 10, 6 and 3 kb. These mRNAs were profoundly decreased in livers from newborn rats and relatively decreased in regenerating rat livers. beta-Actin mRNA in these tissues showed a tendency to increase over that of the adult controls.

Animals↗
PubMed1990

Growth and fecundity of Schistosoma japonicum in mice maintained at different environmental temperatures.

On weeks 7 and 9 post infection (PI), the number of Schistosoma japonicum in mice maintained at low (5 degrees C) and high (32 degrees C and 35 degrees C) temperatures did not differ from those in controls (25 degrees C), but shorter males were observed in hosts at 5 degrees C. Further, both male and female worms recovered on week 7 PI from mice kept at 35 degrees C were shorter than those recovered from controls. Staining analysis revealed that worm maturation was not affected in mice kept at 5 degrees C and 32 degrees C. However, some female worms from mice kept at 35 degrees C had no eggs in the uterus. The day of patency of worms in the temperature-stressed mice did not differ from that in controls. EPG in mice kept at 32 degrees C rose to a high level on weeks 7-8 PI which was about 10 times as many as those in control mice, while EPG in mice kept at 5 degrees C appeared to be lower than in controls. The 7-week tissue egg count revealed that the hot- and cold-stressed mice supported significantly less egg productivity per female worm than control mice. The environmental temperature could not alter the migration pattern of schistosomula from the skin to lungs in mice.

Animals↗
PubMed1990

[Acute myeloblastic leukemia associated with 46, XY, del(5)(q22)].

A 38-year-old male admitted to the Internal Medicine of Surugadai Nihon University Hospital, complaining of general fatigue and throat pain. The laboratory examinations revealed leukocytosis (83, 900/microliters) and an appearance of myeloblasts (90.2%) in the peripheral blood. The nucleated cell count was 56 x 10(4)/microliters with 85.5% myeloblasts in bone marrow. He was diagnosed as acute myeloblastic leukemia (AML). Though he received two courses of combination chemotherapy with daunorubicin, BH-AC, 6 MP and prednisone, one course of combination with mitoxantrone, etoposide and cytosine arabinoside and one course of combination with aclarubicin cytosine arabinoside and prednisone, he could not achieved remission. A chromosome analysis revealed 46, XY del(5)(q22). The amount of DNA fragments hybridized to 4.5 Kb v-fms probe in blastoid cells was approximately a half amount of normal persons. It is not defined the relationship between the decrease of fms and leukemia in this case. He was diagnosed de novo AML, since he had not been received the therapy with potential mutagenic and carcinogenic agents and had not been exposed the irradiation on his works.

Adult↗
PubMed1989

Epidermal growth factor (EGF) binding, EGF-dependent autophosphorylation and activity of tyrosine-specific protein kinase in hepatic membrane fractions from fetal, newborn, adult and partially hepatectomized rats.

The binding of 125I-epidermal growth factor (EGF) and activities of EGF-receptor autophosphorylation and of tyrosine-specific protein kinases were determined in hepatic membrane fraction from newborn, fetal and hepatectomized adult rats and compared with those of adult control rats. Although the EGF binding was decreased, there was a tendency for the activity of autophosphorylation to be higher and ligand-dependency to be lower in the membranes from growing hepatic tissues. The activity of tyrosine kinases did not differ among animal groups but a supplement of (NH4)2SO4 to the incubation mixture revealed a difference in the EGF-dependency of the activity; the salt inhibited the activity in the control more profoundly than in the newborn and fetus but the activity was partially restored in the presence of EGF, while in the newborn and fetus the activity did not respond to the added EGF. The results suggest that the higher activity with less responsiveness to the ligand of EGF-receptor autophosphorylation and protein-tyrosine kinase is one of the characteristics of growing rat hepatic tissues.

Aging↗
PubMed1988

The effects of sodium valproate on plasma somatostatin and insulin in humans.

To determine the role of gamma-aminobutyric acid (GABA) in islet tissue, sodium valproate (1600 mg/day) was administered for 6 days to 10 normal subjects and 1 patient with a somatostatinoma. Plasma valproate concentrations reached a steady state by the third day accompanied by elevation of plasma GABA concentrations. Sodium valproate administration resulted in a 40% decrease in plasma somatostatin concentrations in the normal subjects and a 63% decrease in the somatostatinoma patient, respectively, compared to the response to placebo. Plasma C-peptide concentrations did not change in any subject. Fasting blood glucose levels decreased in the somatostatinoma patient during sodium valproate administration. These results suggest that endogenous GABA may play some role in the release of somatostatin, but not in the release of insulin.

Adult↗
PubMed1988

Cloning of glucocorticoid-responsive mRNA in the rat thymus.

To elucidate the molecular mechanism of rat thymus involution induced by administration of glucocorticoid, we screened a cDNA library for polysomal poly(A)+RNA from adrenalectomized rat thymi by a differential colony hybridization method. Labeled cDNAs for mRNAs isolated from thymi of adrenalectomized rats and rats receiving dexamethasone (Dex) treatment were used as probes. Eight cDNA clones for mRNAs which had a diminished response to administration of Dex were isolated. The relative concentration of cloned mRNAs in the thymic polysomal RNA was significantly decreased 3 h after hormone administration, while changes in the nuclear RNA were not significant after Dex administration. One of the selected cDNA clones designated pRTGR-8 corresponded to mRNA of about 3,000 nucleotides, and a nuclear run-off transcription assay indicated that the rate of transcription of pRTGR-8 RNA was repressed by Dex administration. The cloned cDNAs obtained in this experiment may provide useful probes for studying the negative regulation mechanism of gene expression by glucocorticoids.

Animals↗
PubMed1988

Binding sites for epidermal growth factor in nuclear fraction from rat liver.

Binding sites for mouse epidermal growth factor (EGF) were observed in purified nuclear fraction from rat liver. The binding data yielded a curvilinear Scatchard plot which was decomposed into two binding components with different binding affinities. The binding component with higher affinity (Kd approximately 10(-10) M) represented approximately 15% of the total binding, while the high affinity binding sites were less than 5% of the total in the microsomes. The ligand-dependent autophosphorylation, one of the characteristic features of EGF receptor in the plasma membrane, was not observed at the site of the receptor (170 KDa) in the nuclear fraction. The binding characteristics for EGF fluctuated during the course of liver regeneration after partial hepatectomy; the binding capacity in the nuclear fraction increased in contrast to the decrease in the microsomes. However, the binding sites in the nuclear fraction obtained in the early period after partial hepatectomy consisted only of low affinity ones.

Animals↗
PubMed1986

Receptor binding in the rat liver nuclear matrix.

3H-Dexamethasone (Dex)-receptor complexes prepared from the rat liver cytosol efficiently bound to the nuclear matrix from the same tissue. The binding was increased with the concentration of the 3H-Dex-receptor complex added and reached a maximum plateau. However, when the partially purified 3H-Dex-receptor complex was used, saturation of the binding sites in the nuclear matrix was not observed in the range of concentration of 3H-Dex-receptor complex used. Therefore, it was considered that the apparent saturability observed in the binding of the unpurified receptor complexes is caused by the translocation inhibitor(s) in the cytosol. When the binding capacity was expressed on the basis of unit weight of DNA, the nuclear matrix exhibited 20 times more of that of the unfractionated nuclei. However, no line of evidence of enrichment of the binding sites in the DNA isolated from the nuclear matrix was observed. These observations show that the role of the nuclear matrix in the action of glucocorticoid is quite uncertain.

Animals↗
PubMed1986

The killing effect of subclasses of mouse IgG antibodies on schistosomula of Schistosoma japonicum.

The killing effect of IgG antibodies in sera from S. japonicum infected mice on schistosomula of S. japonicum was studied in vitro in the presence of complement. Immune mouse sera were fractionated over Protein A-Sepharose and IgG1, IgG2a, IgG2b and IgG3 were purified by affinity chromatography. The killing activity of each subclass of IgG antibodies against schistosomula was observed only in the presence of complement. The activity of IgG1 was higher than that of the other subclasses of IgG. In combination of the two or three subclasses of IgG, the additive mortality rate was given in all combinations of each subclass of IgG. These results support the view that the combination of various subclasses of IgG antibodies potentiates the resultant lethal effect on schistosomula.

Animals↗
PubMed1985

Effect of colchicine on the depletion and replenishment of cytoplasmic glucocorticoid receptor in rat liver after administration of glucocorticoid.

Pretreatment of rats with colchicine (3 mg/kg body weight) modified the time course of depletion of the cytoplasmic binding sites for 3H-dexamethasone after administration of prednisolone (0.5 or 1.5 mg/kg body weight). Colchicine also decreased the rate of the cytoplasmic receptor replenishment which was confirmed by application of this drug after completion of the cytoplasmic receptor translocation to nuclei (30 min after prednisolone injection). Addition of colchicine to the incubation mixture for in vitro binding of 3H-dexamethasone-labelled liver cytosol to isolated liver nuclei suspended in TKMS buffer (50 mM Tris-HCl, pH 7.5, 50 mM KCl, 5 mM MgCl2 and 250 mM sucrose) evoked no measurable changes in the rate of the nuclear binding.

Animals↗
PubMed1985

Properties of binding of partially purified glucocorticoid receptor from rat liver with glucocorticoids of different biopotencies.

To elucidate the relationship between binding parameters and biopotencies of glucocorticoids, we partially purified the receptor from the liver cytosol of rats in a dexamethasone-bound and unactivated form by precipitation with protamine sulfate, gel filtration and DEAE-cellulose chromatography (approximately 100-fold) and examined the interaction of the preparation with 3 glucocorticoids of different biopotencies (dexamethasone; Dex, corticosterone; Cort and prednisolone; Pred). The partially purified receptor (PPR) was stable at -20 degrees C for at least 2 months in the presence of bovine serum albumin, glycerol, molybdate and dithiothreitol. Treatment of the PPR with p-hydroxymercuribenzoate liberated the ligands and the treated PPR reassociated 3H-glucocorticoids efficiently following the addition of dithiothreitol. The reassociated PPR was bound to the DNA-cellulose after a brief heating. Metabolic activity on ligands and inactivation of the binding sites in the PPR were insignificant under the conditions used. Kd's were approximately 0.9, approximately 3 and approximately 6 nM for Dex, Cort and Pred, respectively (at 0 degree C). Relative binding affinity of ligands to the PPR which was estimated by competitions was higher in the order of triamcinolone acetonide greater than Dex greater than Cort greater than Pred greater than progesterone greater than cortexolone. Association of Dex and Cort was relatively rapid and significantly accelerated by raising the incubation temperature, while the association of Pred was slower and effects of the temperature was moderate. The rate of dissociations was also varied with ligands. The rate of dissociation of Dex was the lowest among the 3 ligands and was elevated by raising the temperature. Because the effect of temperature was more pronounced in the dissociation than in the association, apparent Ka's decreased at higher temperature. Thermodynamic examinations of glucocorticoid binding in the PPR revealed that the binding reaction proceeds at a higher rate in the order of Dex greater than Cort greater than Pred. Because the relative biopotencies of these 3 glucocorticoids in vivo is higher in the order of Dex greater than Pred greater than Cort, from the results obtained in the present study, it appears that biopotency of glucocorticoids in vivo does not correlate with the affinity of the binding to the receptor estimated in vitro.

Animals↗
PubMed1984

[Morphometric analysis of diameter and density of myelinated and unmyelinated fibers of normal human sural nerves].

Diameter and density of both myelinated and unmyelinated fibers were morphometrically analyzed in 8 sural nerves obtained from 8 normal volunteers by utilizing a TGA-10 particle analyzer (Carl Zeiss Co., West Germany). The density of total myelinated fibers was (7.4 +/- 1.3) X 10(3) (mean +/- standard deviation) per square millimeter. The border diameter between small and large myelinated fibers was 5.4 +/- 0.5 micron. The densities of small and large myelinated fibers in cross sectional areas were (4.5 +/- 0.9) X 10(3) and (2.9 +/- 0.7) X 10(3) per square millimeter, respectively. The density of unmyelinated fibers was (27.9 +/- 5.8) X 10(3) per square millimeter. The peak and the median diameters in the size distribution of unmyelinated fiber diameters were 0.88 +/- 0.15 and 0.86 +/- 0.12 micron, respectively. The mean distribution histograms of the sizes of both myelinated and unmyelinated fibers of 8 sural nerves were also established. The morphometric findings obtained in this study serve as control in histopathologic analysis of the sural nerves from the patients with various peripheral neuropathies.

Adult↗
PubMed1984

Cytoplasmic inhibiting factors for 3H-dexamethasone binding to glucocorticoid receptors in rat tissues.

Factors which specifically inhibit 3H-dexamethasone binding to unoccupied glucocorticoid receptors were examined in cytosols of the seminal vesicle and ventral prostate of rats. The inhibiting factors are mostly precipitated at 40-50% saturation of (NH4)2SO4 and eluted from a Sephacryl S-200 column immediately after the elution volume of bovine serum albumin. The inhibitory activity was relatively heat-stable and decreased to approximately 35% of the initial activity by trypsin digestion. These results suggest that the inhibiting factors are of a polypeptide-like nature. The inhibitory activity of the factors seems to be blocked by treatment with dithiothreitol and molybdate. The inhibiting factors act to decrease the binding affinity of glucocorticoid receptors to 3H-dexamethasone without altering the number of the available binding sites in cytosols. These results indicate that the binding of glucocorticoid receptors to ligands in vitro is influenced by a number of factors.

Adrenalectomy↗
PubMed1984

Glucocorticoid receptor in the rat uterus.

3H-Dexamethasone binding sites with a Kd of approximately 0.7 nM and a maximum number of binding sites of approximately 0.3 pmoles/mg protein were demonstrated in the uterine cytosol of adrenalectomized rats only if dithiothreitol was present in the incubation mixture and the simultaneous presence of molybdate further enhanced the binding in the cytosol. The binding sites exhibited a high specificity for glucocorticoids and were depleted in a dose-dependent manner from cytosol after administration of dexamethasone to animals. The depletion was not due to the occupation of the binding sites by the dexamethasone administered and the rate of depletion was correlated with the inhibition of uterine growth induced by estrogen administration. The cytosol labeled with 3H-dexamethasone in the presence of dithiothreitol bound to DNA-cellulose efficiently after heating at 25 degrees C for 30 min and the binding was inhibited by pyridoxal 5'-phosphate added to the reaction mixture. The effect of heating on the DNA-cellulose binding was abolished by molybdate in the incubation mixture. From these observations, it was concluded that 3H-dexamethasone binding sites in the rat uterus were physiologically active glucocorticoid receptors.

Adrenalectomy↗