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T Satoh

Publications and source records attributed to T Satoh.

At least 631 records · Page 35Linked to original sources
PubMed1994

Ligand (T3) dependent and independent effects of thyroid hormone receptors upon human TRH gene transcription in neuroblastoma cells.

Thyrotropin releasing hormone (TRH) gene is regulated negatively at the transcriptional level by thyroid hormone (T3) in rat anterior hypothalamus. The actions of T3 upon other target genes are known to be mediated through the thyroid hormone receptors (TR), TR alpha and TR beta. To explore whether the inhibitory regulation of human (h) TRH gene transcription by T3 is TR isoform specific and whether TRH gene transcription can be modulated as well by unliganded TR isoforms, transient gene expression studies have been carried out using hTRH-luciferase (TRH-Luc) chimeric constructs and TR expression constructs, co-transfected into a human neuroblastoma cell line (HTB-11). Data herein demonstrate T3-dependent inhibitory regulation of the hTRH gene promoter by TR-T3 complexes. Moreover, significant inhibition (39%-60%) could be achieved by T3 bound to either hTR alpha 1, hTR beta 1, or rTR beta 1, beta 2 and was comparable quantitatively, indicating an absence of TR isoform specificity for T3 inhibition. Conversely, basal promoter activity of the hTRH gene could be activated significantly by unliganded hTR alpha 1, beta 1, rTR beta 1, and beta 2 (150% to 334%), but not by hTR alpha 2. Thus, TRs appear to exert opposite effects on hTRH gene transcription, depending on the presence or absence of ligand (T3). These dual effects of TR suggest that the addition of the T3 ligand effects conformational changes that can abrogate the initiation of transcription.

Animals↗
PubMed1994

Identification of a liver preference enhancer element of the rat hemopexin gene and its interaction with nuclear factors.

Transcription of hemopexin (Hx) occurs predominantly in the liver. To investigate the contribution of the cis-acting enhancer element to the hepatocyte preferential expression, we performed chloramphenicol acetyl-transferase (CAT) assays in HepG2 cells. A strong enhancer element was identified by successive truncation to reside in the region -157/-104 from the cap site. The Hx region -145/-125 interacts with rat liver nuclear proteins, as shown by standard DNA-protein binding assays. The nucleotide sequence -141AGACTTTGACCT-130 includes, in reverse orientation, a direct repeat of the imperfect AGGTCA sequence, one of the recognition motifs of the steroid-thyroid hormone receptor superfamily. That this AGGTCA repeat is an enhancer core of the Hx element was affirmed by mutational analyses. In electrophoretic mobility shift assays, oligonucleotides, corresponding to binding regions of chicken ovalbumin upstream promoter transcription factor (COUP-TF) and apolipoprotein AI regulatory protein 1 (ARP-1) but not of hepatocyte nuclear factor-4 (HNF-4), competed with the Hx element for binding sites. Co-transfection analyses indicated that HNF-4 does not affect CAT expression whereas ARP-1 and COUP-TF repress it. Antibody supershift analyses suggested that HNF-4 and COUP-TF may not be major factors binding to the Hx element.

Animals↗
PubMed1994

Determination of tomatine in foods by liquid chromatography after derivatization.

A liquid chromatographic method for measuring tomatine levels in tomatoes and tomato products was developed. Tomatine was extracted with 1% acetic acid and purified on a C18 cartridge. Tomatine in the eluate was acetylated with acetic anhydride and isolated on a C18 cartridge. The solvent in the eluate was evaporated and the residue was dissolved in acetonitrile. An aliquot was injected into an Inertsil ODS-2 HPLC column and the acetylated tomatine was measured at 205 nm using a UV detector. The limit of determination was 1 microgram g-1. Tomatine was detected in the green portions of tomatoes and in tomato ketchups and juices at levels below 7 micrograms g-1.

Acetylation↗
PubMed1994

Stimulatory effect of a phorbol ester on expression of insulin-like growth factor (IGF) binding protein-2 and level of IGF-I receptors in mouse osteoblastic MC3T3-E1 cells.

We examined the relationship between signal transduction and the expression of insulin-like growth factor I (IGF-I), IGF-I receptor level, and IGF binding proteins (IGFBPs) in murine clonal osteoblastic MC3T3-E1 cells. 12-O-Tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C, decreased the secretion of immunoreactive IGF-I into the medium, whereas dibutyryl cAMP (Bt2cAMP) augmented the secretion. In contrast, TPA increased the level of type I IGF receptor on the cells. Furthermore, MC3T3-E1 cells produced and secreted at least three different IGFBPs with molecular masses of 24, 30, and 34 kDa, and the 24-kDa IGFBP was predominant under normal conditions. However, TPA specifically increased the secretion of the 34-kDa IGFBP. The N-terminal amino acid sequence of the purified 34-kDa IGFBP was nearly identical with that of rat IGFBP-2. Furthermore, the 34-kDa IGFBP was immunoreactive to anti-IGFBP-2 antiserum. The level of IGFBP-2 mRNA in the cells was increased by TPA, indicating that the increase in IGFBP-2 secretion results from the stimulation of IGFBP-2 production. In contrast, Bt2cAMP affected neither IGF-I receptor number nor the IGFBP secretion. These results indicate that the production of IGF-I and the expression of IGF-I receptors and IGFBP-2 are up-regulated by the activation of adenylate cyclase and protein kinase C, respectively, in osteoblastic MC3T3-E1 cells.

Adenylyl Cyclases↗
PubMed1994

An acute effect of triazolam on muscarinic cholinergic receptor binding in the human brain measured by positron emission tomography.

An acute effect of triazolam, a potent benzodiazepine agonist, on cholinergic receptor binding in the human brain was measured by PET (positron emission tomography) using [11C]N-methyl-4-piperidylbenzilate ([11C]NMPB), a potent muscarinic cholinergic receptor antagonist. Two PET scans were performed in each subject: (1) control scan; (2) after oral administration of 0.5 mg triazolam or placebo. The previously discussed amnestic effect of triazolam was measured by immediate and delayed recall of meaningful and meaningless syllables. A compartment model employing the radioactivity in the cerebellum as an input function was used for the quantification of receptor binding. The binding parameter, k3, was decreased after triazolam administration in all measured regions, whereas no change was observed after placebo treatment. The reduction compared to the control study varied from 8.6 +/- 3.7% in the temporal cortex to 16.3 +/- 6.3% in the thalamus. Triazolam administration impaired both immediate and delayed recall of syllables, whereas placebo administration had no effects. Benzodiazepine agonists are reported to decrease the cortical acetylcholine release. The decrease of acetylcholine release in the synaptic cleft might be the explanation for the decreased binding of [11C]NMPB.

Adolescent↗
PubMed1994

A case of metastatic chondrosarcoma of the stomach.

A case of metastatic chondrosarcoma of the stomach in a 34-year-old female is reported. This patient had been diagnosed as having chondrosarcoma of the right knee and was operated on in 1984. Thereafter, there was repeated local recurrence and operations were performed on multiple metastases, including those of the lung, brain, ovary and spleen. In September, 1990, the patient was readmitted because of advanced anemia. Gastroendoscopy disclosed a firm elevated lesion with central irregular erosion. Histologically, there was cellular atypical cartilage with pleomorphic chondrocytes, which showed the same staining reactions as those in the primary lesion. Therefore this case was diagnosed as metastatic chondrosarcoma. This may be the first documentation of a case of gastric metastasis of chondrosarcoma.

Adult↗
PubMed1994

Evaluation of transvaginal color Doppler sonography, transvaginal sonography and CA 125 for prediction of ovarian malignancy.

OBJECTIVES: To evaluate the efficacy of color Doppler ultrasonography as the predictor of malignant ovarian tumors and to compare the results with CA 125 levels and ultrasonographic morphological patterns. METHODS: We compared color Doppler ultrasound with sonographic findings and serum CA 125 levels for predicting ovarian malignancy in 16 patients with malignant and 12 patients with benign ovarian tumors. RESULTS: There was a significant difference in pulsatility index (PI) value of ovarian vessel between benign and malignant tumors (2.42 +/- 0.67 for benign and 1.35 +/- 0.78 for malignant, respectively, P < 0.01). The specificity of morphological findings and CA 125 was lower than that of PI measurements, but sensitivity was not different between the three methods. In addition, the combination of color Doppler and CA 125 or morphological assessments resulted in a sensitivity of 100% and a negative predictive value of 100%, respectively. CONCLUSION: PI measurements by transvaginal color Doppler ultrasound combined with CA 125 levels or morphological findings could be an accurate and appropriate screening method for ovarian tumors.

Adult↗
PubMed1994

Mechanism of inhibitory actions of minocycline and doxycycline on ascitic fluid production induced by mouse fibrosarcoma cells.

Semisynthetic tetracyclines (TCNs) are used for the management of malignant pleural effusions as sclerosing agents. However, their precise mechanism of actions are uncertain. In the present study, the mechanism of inhibitory effects of minocycline (MINO) and doxycycline (DOXY), on the accumulation of ascitic fluid induced by mouse fibrosarcoma (Meth-A) cells were investigated using male mice. Meth-A cells inoculated intraperitoneally elicited 2.5-4 ml of bloody ascites 10 days after implantation. The production of ascitic fluid was suppressed in a dose-related manner by daily intraperitoneal injections of MINO or DOXY, whereas vehicle (normal saline with 0.01N HCl) did not exert a significant effect. The inhibitory activity of these two substances was quite similar; one mg/mouse of MINO or DOXY inhibited the accumulation of fluid by 87% and 84%, respectively. The survival rate of Meth-A-bearing mice treated with MINO or DOXY was higher than that of the controls. Macroscopic examination of the peritoneal cavity did not reveal any obvious effects, such as adhesions, in mice treated with either MINO or DOXY. In vitro studies showed that MINO and DOXY suppressed Meth-A cell growth with IC50s of 5 microM and 8 microM, respectively. Maximal suppression (95%) was achieved at MINO and DOXY concentrations of 25 microM. The above observations suggest that MINO and DOXY inhibit the accumulation of ascites by a direct effect on Meth-A cell growth. Therefore, it appears that TCNs injected into the pleural cavity to manage malignant effusions in man exert their activity, at least in part, by suppressing malignant cell growth.

Animals↗
PubMed1994

Identification of thyrotropin-releasing hormone receptor in the rat testis.

We have recently documented the expression of preprothyrotropin-releasing hormone (TRH) gene in murine, human and rat testis. Moreover, we have localized TRH to rat Leydig cells immunohistochemically, and found that both prepro TRH mRNA and TRH levels are developmentally regulated in the rat testis. To investigate the potential roles of TRH in testicular function, characterization of TRH receptors (TRH-R) in this tissue was undertaken. Recently, a cDNA encoding murine TRH-R has been isolated, making possible cloning of a rat TRH-R cDNA from the anterior pituitary gland. This cDNA was used for detection of TRH-R gene expression in the rat testis by Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR). TRH receptor assays were also performed with (3H)MeHisTRH as the radioactive ligand. In Northern blot analysis, a single and specific hybridization band, approximately 3.8 kb in size, was identified in whole testis RNA, identical in size with that found in the anterior pituitary gland. The concentration of TRH-R mRNA in the testis was approximately 10% of that in the pituitary. TRH-R mRNA was also detected by RT-PCR in Metrizamide gradient-purified Leydig cells. TRH receptor binding assays revealed the presence of specific, high affinity binding sites with a Kd of 1.6 x 10(-8) M in the testis. Such TRH binding was inhibited by chlordiazepoxide, a specific antagonist of TRH receptor binding. We conclude that TRH may exert local, probably autocrine, actions in the testis via a transmembrane receptor very similar or identical to that in pituitary.

Animals↗
PubMed1994

Work environment of plants manufacturing asbestos-containing products in Japan.

In 1985, a comprehensive study of asbestos-containing product plants (A/C, friction, textile) was performed. The data presented were based not on personal but on area sampling. A conversion equation from area sampling data to personal exposure values was developed. Exposure concentrations were 0.07-0.66 f ml-1. In workplaces which belonged to member companies of the Japan Asbestos Association, the percentage of workplaces whose exposure concentrations was less than 0.3 f ml-1 was 70% in 1985 (N = 510), but 98% in 1992 (N = 430). Concentrations in a new, well-controlled A/C plant were less than 0.1 f ml-1.

Asbestos↗
PubMed1994

Urine concentrating ability after prolonged sevoflurane anaesthesia.

Few studies have used the vasopressin test to evaluate urine concentrating ability after sevoflurane anaesthesia. We performed a vasopressin test on the first day after operation to compare the effect of prolonged sevoflurane anaesthesia for orthopaedic procedures (n = 11) with that of isoflurane (n = 10). Mean doses of sevoflurane and isoflurane were 10.6 (SE 0.9) and 8.5 (1.5) MAC-h, respectively. Mean peak serum fluoride concentration in patients anaesthetized with sevoflurane was 41.9 (2.5 mumol litre-1 and exceeded 20 mumol litre-1 for approximately 20 h. Each group showed similar responses to vasopressin. There was no evidence of subclinical nephrotoxicity in patients given prolonged sevoflurane anaesthesia.

Adult↗
PubMed1994

Purification and properties of six aldo-keto reductases from rat adrenal gland.

Six aldo-keto reductases from rat adrenal gland have been highly purified to apparent homogeneity. These enzymes were identified as carbonyl reductases (CR-K1, CR-K2, CR-A, and CR-B), aldehyde reductase (AR-H), and aldose reductase (AR-L) in terms of substrate specificity, molecular weight (33,000-39,000), inhibitor susceptibility, cofactor requirement, and immunochemical properties. Both CR-K1 and CR-K2 were characterized as possessing high affinity towards 13,14-dihydro-15-ketoprostaglandin F2 alpha and were localized immunohistochemically in the zona glomerulosa and the zona reticularis of adrenal cortex, and in the ganglion cell of adrenal medulla. Immunoreactive proteins to anti-CR-K2 antibody were observed in male and female reproductive tissues of rats. Positive immunoreactive protein to anti-CR-A antibody was found in mouse, hamster, and rabbit adrenal gland, whereas that to anti-CR-K2 antibody was present only in rat adrenal gland. AR-H and AR-L mainly reduced aromatic and aliphatic aldehydes. All the aldo-keto reductases from rat adrenal gland were completely inhibited by p-chloromercuribenzoate. Barbiturate and 3,3'-tetramethylene glutarate potently inhibited AR-H, and quercitrin significantly decreased the activity of CR-K1, CR-K2, and AR-L. We propose that these aldo-keto reductases may play important roles in the rat adrenal functions.

Adrenal Cortex↗
PubMed1994

Tissue inhibitor of metalloproteinases (TIMP-1) produced by granulosa and oviduct cells enhances in vitro development of bovine embryo.

Embryogenesis-stimulating activity (ESA) was found in serum-free conditioned media (CM) of bovine cumulus/granulosa cells (BGC) and bovine oviductal epithelial cells (BOEC). The CM of BGC (BGC-CM) contained two molecular species of ESA, one with a low molecular weight (M(r) 30,000) and another with a high molecular weight (M(r) 80,000); but only the activity with low molecular weight was detected in CM of BOEC by gel-permeation chromatography. The smaller ESA (embryogenin-1) in BGC-CM was purified to homogeneity, as a common activity in both CM by a combination of gel-permeation chromatography, ion-exchange chromatography, and reverse-phase HPLC. Embryogenin-1 has a molecular weight of 31,100 (reduced) and has been identified as a bovine tissue inhibitor of metalloproteinase-1 by NH2-terminal amino acid sequence analysis. Western blot analysis, anti-proteinase activities against metalloproteinases, and the nucleotide sequence of cDNA isolated from a lambda gt11 cDNA library of the bovine ovary by a polyclonal antibody against embryogenin-1. These data suggest that the tissue inhibitor of metalloproteinase-1 produced by BGC and BOEC is a major ESA for in vitro development of bovine embryos.

Amino Acid Sequence↗
PubMed1994

Purification and molecular cloning of bovine oviduct-specific glycoprotein.

A specific 85-97-kDa (95-kDa) glycoprotein was found in bovine oviductal tissue and fluid during the follicular phase. In this study, a 95-kDa bovine oviductal glycoprotein (95-kDa BOGP) was purified by wheat germ agglutinin affinity and Mono-Q ion-exchange column chromatography. The first 29 NH2-terminal amino acid residues were determined by gas-phase microsequencing. A cDNA expression library prepared from poly(A)+ RNA isolated from bovine oviducts was screened with a monoclonal antibody to 95-kDa BOGP. A single positive clone containing a approximately 2-kb cDNA insert was isolated. The coding region contained 1612 bp translating to 537 amino acids. The derived amino acid sequence contained a partial signal sequence of 18 amino acids followed by 29 amino acids that were identical to the NH2-terminal amino acids determined by protein sequencing of purified 95-kDa BOGP. The amino acid sequence predicted a mature protein of 519 amino acids (57,684 daltons) containing one potential N-linked glycosylation site and five cysteines. Northern blot hybridization with a digoxigenin-labeled probe indicated that a single message of approximately 2.5 kb was present in oviductal RNA, and this message was detected in significantly greater amounts in oviductal RNA during the follicular phase than during the luteal phase. The amino acid sequence of a portion of 95-kDa BOGP was highly homologous (71% identity) to that of a baboon oviduct-specific glycoprotein.

Amino Acid Sequence↗
PubMed1994

A rapid colorimetric assay for determination of leukocyte-mediated inhibition of mycelial growth of Candida albicans.

A staining method with crystal violet (CV) was demonstrated to be useful for a simple, quick and objective assessment of in vitro growth inhibitory activity of leukocytes against Candida albicans cells. Candida cells incubated with murine neutrophils or macrophages for 14 hr in microwells were stained with CV and, after washing with 0.25% sodium dodecyl sulfate (SDS), treated with isopropanol containing HCl (0.04 N) to extract Candida cell-bound CV. Then the absorbance at 590 nm of the isopropanol extract was photometrically measured. The results showed that the photometrical absorbance was proportional to the amount of 3H-glucose taken up by C. albicans cells, which reflected the number of viable Candida cells.

Animals↗
PubMed1994

[Investigation of Chlamydia trachomatis-specific IgA, IgG antibody with EIA method].

Recently, two new kits, HITAZYME (Hitachi Chemical Co., Ltd.) and SERO IPALISA (Savyon Diagnostics, Ltd.), for the assay of anti-C. trachomatis antibodies by the enzyme immunoassay (EIA) method have been developed and put into clinical application. In the study reported here, the authors investigated the clinical usefulness of these assay kits, together with the IPAzyme and micro-IF test, in the diagnosis of cases of urogenital tract C. trachomatis infections. 1. The positive rates for IgA antibodies, which are considered to be an indicator of active infection, obtained with the HITAZYME and SERO IPALISA kits in the 82 antigen-positive cases were significantly (p < 0.005) higher than the rates obtained with the IPAzyme and micro-IF test. These results showed the usefulness of the HITAZYME and SERO IPALISA kits for detecting C. trachomatis infections. 2. A comparison was made of the assay results obtained with the HITAZYME and SERO IPALISA kits, and it was found that there was a large number of cases (142) that tested negative for IgA antibodies with the HITAZYME but positive with the SERO IPALISA kit. We carried out a confirmatory test on the specimens of cases for which the results obtained with the HITAZYME and SERO IPALISA kits were not in agreement. This test employed the Western blotting method using COMC (the antigen extracted from EB of C. trachomatis strain L2 and used in the HITAZYME kit) and whole EB of C. trachomatis strain L2 (the antigen used in the SERO IPALISA kit). The results showed a significantly higher degree of agreement between the HITAZYME kit data and the Western blotting data than between the SERO IPALISA kit data and the Western blotting data. 3. In addition, with the objective of investigating the existence of cross reactivity with anti-C. pneumoniae antibodies, we performed Western blotting using as the antigen crude whole EB of C. pneumoniae strain TW-183. The results showed that anti-C. pneumoniae antibodies were detected in 25 of 35 (71.4%) cases that were negative with C. trachomatis antigen and the HITAZYME kit and positive with the SERO IPALISA kit. These findings indicate a strong possibility that these cases positive with the SERO IPALISA kit are due to a cross reaction with anti-C. pneumoniae antibodies.(ABSTRACT TRUNCATED AT 400 WORDS)

Antibodies, Bacterial↗
PubMed1994

[Studies on local immune response in mouse model of experimental Escherichia coli intrauterine infections].

Studies were conducted to elucidate the immune cell response at infection sites by performing immunostaining of immune cells with a monoclonal antibody in an experimental Escherichia coli (E. coli) mouse uterine infection model. 1. The incidence of uterine infection by E. coli decreased with the passage of time: 4/4 on Day 1, 4/6 on Day 3, 2/6 on Day 7, and 1/6 on each of Days 14 and 21. It was surmised that clearance of the bacteria from the infection sites was being carried out by immune cells. 2. Beginning from infection Day 1, the infected uterine tissue was observed to undergo a moderate degree of invasion by neutrophils, macrophages, CD4+ T cells, CD8+ T cells and IgA+ B cells. Then, beginning from infection Day 3, there was a mild degree of invasion of the infected uterine tissue by IgM+ B cells and IgG+ B cells. The number of neutrophils in the tissue decreased beginning from infection Day 14, but the degree of invasion of the infected tissue by the other kinds of immune cells remained almost constant through infection Day 21. 3. A comparison was made of the immune responses to local infection by E. coli, and Chlamydia trachomatis (C. trachomatis), an intracellular parasite. It was found that the invasion of the infection site by immune cells occurred earlier in the case of E. coli infection than C. trachomatis infection. In addition, the C. trachomatis infection site was observed to contain greater numbers of macrophages and CD8+ T cells play important roles in the immune defense at sites of infection by C. trachomatis.

Animals↗