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T Satoh

Publications and source records attributed to T Satoh.

At least 901 records · Page 50Linked to original sources
PubMed1990

Mycoplasmas induce transcription and production of tumor necrosis factor in a monocytic cell line, THP-1, by a protein kinase C-independent pathway.

We demonstrated that mycoplasmas (MP), previously shown to augment the antitumor activity of murine peritoneal macrophages, also induce cytotoxic activity in a human monocytic cell line, THP-1. THP-1 cells were induced to produce cytotoxic activity by MP in a time- and dose-dependent manner. By using neutralization by antibody against tumor necrosis factor (TNF), the cytotoxic activity was shown to be due to TNF released from the MP-stimulated cells. Studies with inhibitors of second-messenger pathways and Northern RNA blot analysis indicated that a Ca2(+)-dependent, but not protein kinase C-dependent, biochemical pathway is involved in MP-induced TNF production by THP-1 cells and that MP induce TNF production in the cells at the level of transcription. MP, unlike other bacteria, lack cell walls and lipopolysaccharide. The possible involvement of a TNF production mechanism distinct from that triggered by lipopolysaccharide is discussed.

Animals↗
PubMed1990

Inhibitory effect of phorbol ester on sodium transport in frog urinary bladder.

To confirm the role of protein kinase C (PKC) on epithelial Na transport, we studied the effects of phorbol 12-myristate 13-acetate (PMA) and dioctanoylglycerol (DiC8), activators of PKC, on short-circuit current (Isc) in frog urinary bladder and further examined the influence of sphingosine, an inhibitor of PKC, on PMA- or DiC8-modulated Isc. PMA reduced basal Isc in a dose-dependent manner, and sphingosine (10 and 100 microM) partially restored PMA-reduced Isc. On the other hand, DiC8 (5 x 10(-5) M) also reduced basal Isc, and this action was completely prevented by 100 microM sphingosine. Both PMA (4 x 10(-5) M) and DiC8 inhibited vasopressin (50 mU/ml)- and forskolin (5 x 10(-5) M)-stimulated increases in Isc. PMA (4 x 10(-5) M) also inhibited 8-bromoadenosine 3',5'-cyclic monophosphate (8-BrcAMP)-stimulated increase in Isc. Furthermore, PMA (4 x 10(-5) M) and DiC8 (5 x 10(-5) M) inhibited vasopressin (50 mU/ml)-stimulated cAMP accumulation. DiC8 also inhibited forskolin-stimulated cAMP accumulation. These results indicate that PMA exerts inhibitory influence on Na transport mainly by its own potency of PKC activation. In addition, it is suggested that there is a cross talk in epithelial Na transport between PKC and cAMP-dependent pathway in frog urinary bladder.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1990

Synchronized discharge of taste neurons recorded simultaneously in rat parabrachial nucleus.

1. Cross-correlation analysis was made in the taste-sensitive neuron pairs recorded simultaneously from the parabrachial nucleus (PBN) of rats. Three indexes were adopted to evaluate the activities of the taste neurons; namely, 1) spike response density (RD value), which is the net spike density to stimulation with the four basic tastes; 2) the frequency of correlated discharges (FC value in spikes per second), which was determined by measuring the area of the peak appearing in the cross-correlogram (CC) during application of the test fluids; and 3) the weight of correlated discharge (WC = FC/RD), which shows the relative importance of correlated discharges in the taste signals delivered by a component neuron of a given pair. 2. In 11 of 23 pairs, the CCs exhibited peaks during stimulation with tastants. These 11 pairs, which were recorded in the pontine taste area, were composed of 18 NaCl-best (most sensitive to NaCl) and 4 HCl-best neurons. In eight pairs, the best-stimulus of both of the component neurons was NaCl, and it was HCl in one pair (homo-type pairs). The remaining two pairs were composed of an NaCl-best and an HCl-best neuron (hetero-type pairs). 3. In eight homo-type pairs (7 NaCl-best pairs and 1 HCl-best pair), each pair exhibited the maximal FC value during stimulation with the best-stimulus of the component neurons (2.3 less than or equal to maximal FC less than or equal to 26.6 Hz). In the remaining three pairs, the maximal FC values were low (0.8-1.9 Hz).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Recombinant interleukin-2-induced regression of pulmonary metastasis of renal cell carcinoma.

A patient having renal cell carcinoma with multiple pulmonary metastasis was treated with recombinant interleukin-2. Pulmonary metastatic nodes were markedly diminished. The response was maintained for 4 months. At Autopsy, many fibrotic areas in which metastatic carcinoma was thought to have previously existed and then healed were observed in the bilateral pulmonary lobes, although a few microscopically tiny metastatic lesions still remained.

Carcinoma, Renal Cell↗
PubMed1990

In vivo viscoelastic behavior in the human aorta.

To characterize the viscoelastic properties of the human aorta in vivo, the pressure-diameter relation was determined in the abdominal aorta in 15 subjects. Diameter was measured noninvasively with a highly sensitive ultrasonic displacement meter, while intra-aortic pressure was measured with a catheter tip micromanometer inserted from the femoral artery. The frequency-dependent changes in the pressure-strain modulus (Ep) of the aorta and the phase lag of diameter to pressure were calculated by frequency analysis of these wave forms at the mean blood pressure of 109 mm Hg. The Ep and the phase lag at the fundamental frequency component (1.2 +/- 0.3 Hz, mean +/- SD) were (1.52 +/- 0.57) x 10(6) dyne/cm2 and -6.7 degrees +/- 2.1 degrees, respectively. Although the phase lag at the fundamental frequency was in good agreement with the published in vitro data, the calculated phase lags above the second harmonic were inconsistent, which was probably due to the nonlinearity in the pressure-diameter relation. To separate the effect of this nonlinearity, analysis was conducted with a model consisting of a static nonlinear component representing the elasticity and a dynamic linear component representing the viscosity. This method of analysis revealed that the phase lag due to the viscous component provided relatively flat frequency response to the 10th harmonic. It was confirmed that the aortic wall viscosity showed no apparent difference between the in vivo and the in vitro experimental conditions.

Adult↗
PubMed1990

Inhibition of 125I organification and thyroid hormone release by interleukin-1, tumor necrosis factor-alpha, and interferon-gamma in human thyrocytes in suspension culture.

To elucidate the mechanism of decreased 131I uptake by the thyroid gland in patients with subacute thyroiditis and painless thyroiditis, human thyroid follicles were cultured with interleukin-1 (IL-1), tumor necrosis factor-alpha (TNF alpha), and/or interferon-gamma (IFN gamma), and the effects of these cytokines on thyroid function were studied in vitro. When human thyrocytes were cultured in RPMI-1640 medium containing 0.5% fetal calf serum and TSH for 5-8 days, the cells incorporated 125I, synthesized de novo [125I]iodotyrosines and [125I]iodothyronines, and secreted [125I]T4 and [125I]T3 into the medium. IL-1 alpha and IL-1 beta inhibited 125I incorporation and [125I]iodothyronine release in a concentration-dependent manner. The minimal inhibitory effect was detected at 10 pg/ml. Electron microscopic examination revealed a marked decrease in lysosome formation in IL-1-treated thyrocytes. TNF alpha and IFN gamma also inhibited thyroid function in a concentration-dependent manner. Furthermore, when thyrocytes were cultured with IL-1, TNF alpha and IFN gamma, these cytokines more than additively inhibited thyroid function. Although the main mechanism of 131I uptake suppression in the thyroid gland in subacute thyroiditis is due to cellular damage and suppression of TSH release, our present findings suggest that IL-1, TNF alpha, and IFN gamma produced in the inflammatory process within the thyroid gland further inhibit iodine incorporation and at least partly account for the decreased 131I uptake by the thyroid gland in destruction-induced hyperthyroidism.

Cells, Cultured↗
PubMed1990

A possible direct precursor of thyrotropin-releasing hormone, pGlu-His-Pro-Gly, stimulates prolactin secretion in anorexia nervosa.

TRH is produced from its possible direct precursor, pGlu-His-Pro-Gly (TRH-Gly), by alpha-amidating enzyme. The quantitative response of TRH-Gly-stimulated PRL, TSH, and GH was evaluated in nine patients with anorexia nervosa, six age-matched normal women, eight patients with uremia, five patients with acromegaly, and two patients with prolactinoma. Intravenous injection (500 micrograms) of TRH-Gly caused a 2.6-fold increase in PRL secretion in patients with anorexia nervosa (basal level, 10.0 +/- 1.4 vs. 25.9 +/- 2.5 micrograms/L 15 min after injection; P less than 0.01). In contrast, no significant change was observed in TRH-Gly-stimulated PRL secretion in normal women (basal level, 13.5 +/- 2.3 vs. 15.3 +/- 2.5 micrograms/L 15 min after injection; P greater than 0.05). TRH-Gly did not alter PRL levels in patients with uremia, acromegaly, or prolactinoma. Secretion of TSH, but not GH, was slightly increased by TRH-Gly injection in patients with anorexia nervosa (basal level, 1.41 +/- 0.13 vs. 2.86 +/- 0.22 min/L 30 min after injection; P less than 0.01), whereas no significant secretory response was observed in normal women. These data provide evidence that PRL secretion in anorectic patients is quantitatively different from that in normal persons.

Adult↗
PubMed1990

Pharmacological studies of lappaconitine. Analgesia produced by intracerebroventricular, intracisternal and intrathecal injections.

The antinociceptive effects of lappaconitine (LA) and morphine (MOR) when injected intracerebroventricularly (i.c.v.), intracisternally (i.cist.) or intrathecally (i.t.) were investigated in mice by use of the tail pinch, hot plate and acetic acid-induced writhing tests. In addition, the effects of naloxone (NLX) administered subcutaneously on the antinociceptive action of LA and MOR were studied. LA and MOR after i.c.v., i.cist. and i.t. injection produced dose-dependent antinociception. MOR was more potent in the tail pinch and acetic acid-induced writhing tests by i.t. injection than by i.c.v. or i.cist. injection, but the potency in the hot plate test was independent of the injection site. On the other hand, like MOR, LA was more potent after i.t. injection than after i.c.v. or i.cist. injection in the tail pinch and acetic acid-induced writhing test. Its antinociceptive action was less potent than that of MOR. The antinociceptive actions of MOR were antagonized by NLX (1 mg/kg, s.c.) in every test and injection site, whereas the antinociceptive actions of LA were not inhibited, except for the antinociception on the tail pinch test, which was partially antagonized by NLX. It is suggested that LA mainly produced an NLX-resistant antinociceptive effect at the spinal site.

Aconitine↗
PubMed1990

[Effects of lamprey oil prepared under different deodorization conditions on serum lipids, reticuloendothelial system and antibody production in mice].

Fresh lamprey oil (F-La) is known to contain a large amount of eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids. When F-La was deodorized with steam at 280 degrees C and 1 mmHg for 1 h, the contents of EPA and DHA were reduced and unidentified peaks were detected by gas-liquid chromatography. In male ddY mice, one week feeding of the lamprey oil deodorized at 280 degrees C (H-La) remarkably decreased the serum triglyceride level and increased the liver weight 2.0-fold. H-La also lowered the corrected phagocytic index (alpha), which is an indicator of activities of reticuloendothelial system, but suppressed relatively little the antibody production against sheep red blood cells. It is suggested that H-La contains biologically active substances, which have potent hepatotoxic and serum triglyceride-reducing effects. This biologically active substances appear to be derived from long-chain polyunsaturated fatty acids under thermal deodorization conditions.

Animals↗
PubMed1990

[Studies on collagenase inhibitors. II. Inhibitory effects of anthraquinones on bacterial collagenase].

The inhibitory activities of 44 anthraquinones against bacterial collagenase were assayed in vitro. Emodin (1,6,8-trihydroxy-3-methylanthraquinone, 41) was the most potent active inhibitor among them (IC50; 4.0 X 10(-5) M). The type of inhibition by 41 was found to be a mixture type by use of Lineweaver-Burk plots. Since the inhibitory activities of anthraquinones were not affected by the concentration of Ca2+ in the assay medium, it is considered that the inhibitory mechanism is not a chelate effect on Ca2+. In mono-substituted anthraquinones, the compounds which have a substituent (OH or SO3Na) at 2-position show more potent inhibitory activity than the corresponding 1-substituted compound.

Anthraquinones↗
PubMed1990

Effects of heptaminol AMP amidate (HAA) on cyclic AMP level and mitogen-induced proliferation of murine spleen cells.

Heptaminol AMP amidate (HAA), a nucleotide derivative, was found to elevate the intracellular cyclic AMP (cAMP) level of cultured mice spleen cells in a time- and dose-dependent manner. Theophylline and imidazole, when added to the spleen cell culture simultaneously with HAA, respectively caused a further rise and a fall of the cAMP level increased by HAA alone. When comparatively higher doses of the T cell mitogen concanavalin A (Con A) were used in the culture, Con A-induced cell proliferation was mildly inhibited in the culture of spleen cells pooled from HAA administered mice in comparison to the culture of spleen cells pooled from saline treated mice. On the other hand, when another T cell mitogen phytohemagglutinin P (PHA) was used in different concentrations in the culture, there was a trend of enhanced cell proliferation in the culture of spleen cells pooled from HAA administered mice in comparison to the responses in the culture of spleen cells pooled from saline treated mice. The present results supported the previous findings that HAA-mediated immunopotentiation was closely related with a cAMP level elevating property of HAA, and the compound also enhanced the function of helper T cells.

Adenosine Monophosphate↗
PubMed1990

Immunohistochemical localization and physiological regulation of carbonyl reductase in immature rat ovary.

The present study was performed to clarify the role of the ovarian carbonyl reductase (OCR) in ovarian function in immature rats. The OCR activities towards three specific substrates, 13,14-dihydro-PGF2 alpha, 4-benzoylpyridine and menadione, were photometrically and radiochemically determined in the 9,000 x g supernatants of ovaries, and OCR content was measured by Western-blot-peroxidase anti-peroxidase (PAP) analysis. Immunohistochemical localization of the enzyme in the ovary was performed by the avidin-biotin-complex (ABC) method for paraffin sections. Positive immunoreactivity with OCR antibody was observed for the theca cells and interstitial gland cells at 72 hr after pregnant mare serum gonadotropin (PMSG) treatment when ovulation was confirmed, and the granulosa cells were consistently negatively stained. The OCR activity was significantly increased by PMSG, human chorionic gonadotropin (hCG) and PMSG-hCG treatments, but estradiol and tamoxifen overcame the effect of PMSG on the enzyme activity. Moreover, estradiol enhanced the effect of hCG, but tamoxifen did not. Changes in the OCR activity well-correlated with those in the OCR content. These findings indicate that the OCR is regulated by gonadotropin and estrogen and that metabolites formed by the enzyme could be closely involved in ovarian cell function.

Alcohol Oxidoreductases↗
PubMed1990

Coronary artery disease associated with aortitis syndrome in older patients.

Coronary artery disease associated with aortitis syndrome was studied in relation to the coronary artery lesions and age. Four (21%) of 19 patients with aortitis syndrome had coronary artery disease and the mean age of the 4 patients was 53 +/- 14 years. The coronary artery lesions included ostial stenosis in 2 patients and main branch stenosis in 2, but both types of lesion were isolated. The latter patients were older and had coronary lesions like arteriosclerosis on angiogram. Myocardial infarction and congestive heart failure were not present, but a severe coarctation of the aorta was observed in the latter. It was suggested that coronary artery disease might not be rare past middle age, and might include coronary ostial stenosis caused by aortitis and coronary main branch stenosis probably based on secondary arteriosclerosis whose onset was past middle age.

Adult↗
PubMed1990

Metabolic fate of loxistatin in rat.

1. The urinary and plasma metabolites of 14C-loxistatin, a new thiol protease inhibitor, were studied after oral administration to rats. 2. The major metabolites in urine were identified as loxistatin acid (M-1), a pharmacologically active form, and its hydroxy metabolites (M-4a and M-4b). These metabolites were also shown to be the major metabolites in plasma. 3. The inhibitory activity of the synthetic metabolite, M-4b, on papain was almost the same as that of loxistatin acid.

Administration, Oral↗
PubMed1990

Immunohistochemical demonstration of DNA polymerase alpha in human brain-tumor cells.

The proliferative capacity of brain-tumor cells was analyzed in vitro and in situ using monoclonal antibody (MAb) against deoxyribonucleic acid (DNA) polymerase alpha. For the in vitro studies, two cultured human glioma cell lines were investigated using MAb against DNA polymerase alpha, the MAb Ki-67, a serum against proliferating cell nuclear antigen (PCNA/cyclin), bromodeoxyuridine (BUdR), and an anti-BUdR MAb. During exponential growth of the cells, the percentage of polymerase alpha-positive cells (the "polymerase alpha score") ranged from 72.0% to 77.1%, the Ki-67-positive cells (the "Ki-67 score") ranged from 43.4% to 59.4%, the PCNA/cyclin-positive cells from 30.9% to 41.4%, and the BUdR labeling index from 28.6% to 39.3%. For the in situ studies, tissue from 60 human brain tumors and from two normal human brains was investigated and the polymerase alpha scores and Ki-67 scores were compared. In normal brain tissue, no immunostaining was found by either method. In brain tumors, both the polymerase alpha scores and the Ki-67 scores correlated with the histological grade of malignancy. Polymerase alpha scores were generally higher than Ki-67 scores in the same specimen, especially in malignant brain tumors. These findings suggest that immunostaining of DNA polymerase alpha is a convenient and important new method by which to estimate the cellular proliferation rate of brain tumors. Polymerase alpha scores may be closer to the growth fraction of the individual tumor than the MAb Ki-67 or other scores.

Antibodies, Monoclonal↗
PubMed1990

Abnormal hepatobiliary clearance of 99mTc-N-(2,6-diethylphenylcarbamoylmethyl)iminodiacetic acid in the altered state of thyroid--by an analysis of deconvolution method.

Hepatobiliary clearance of 99mTc-EHIDA was investigated in cases with altered thyroid function by deconvolution method. The results indicated that mean hepatic transit time of all control subjects revealed less than 10 minutes. On the other hand, mean hepatic transit time of cases with altered thyroid function revealed prolonged more than 13 minutes. Cases especially showing an elevated serum concentration of TSH compared with normal range (4.6 microU/ml) had a tendency of a high incidence of markedly prolonged mean hepatic transit time. These results suggest that thyroid hormone may influence on the hepatic metabolism of hepatobiliary radiopharmaceuticals. This phenomenon also could partly explain the cause of liver dysfunction seen in subjects with altered states.

Adult↗
PubMed1990

Severe hypersensitivity to mosquito bites associated with natural killer cell lymphocytosis.

A 2-year-old girl showed exaggerated skin reactions to mosquito bites and associated general symptoms, including a high temperature, lymphadenopathy, and hepatosplenomegaly. Peripheral blood lymphocytes contained a high percentage of CD2+, CD3-, CD4-, CD8-, CD11b+, CD16+, CD38+, CD56+, CD57-, and HLA-DR+ large granular lymphocytes that exhibited a marked natural killer cell activity. Immunohistochemically, biopsy specimens taken from the lesional skin demonstrated an infiltrate of the cells bearing the natural killer cell phenotype, indicating a role of these cells in the development of the abnormal skin reactions to mosquito bites and other systemic manifestations. Our case suggests that natural killer cell lymphocytosis may show severe hypersensitivity to mosquito bites as the most outstanding manifestation.

Animals↗