Search PubMed⌕ Search

Biomedical subjects

T Taniguchi

Publications and source records attributed to T Taniguchi.

At least 703 records · Page 39Linked to original sources
PubMed1989

[Thrombotic thrombocytopenic purpura (TTP) associated with chromosomal aberration and treated with plasma exchange].

We reported a case of 69-year-old female presenting with clinically typical TTP which was treated with Ticlopidine and plasma exchanges four times in total and resulted in successful improvement of her clinical state. The first chromosomal analysis of lymphocytes in the peripheral blood of the patient revealed abnormal patterns of 45, XO/46, XX/47, XXX, the second, 45, XO/46, XX/47, XXX/47.XX, + 21. Measurement of FITC-labelled fibrinogen antibody against the fibrinogen combined with platelet glycoprotein GP IIb/IIIa complex using flow cytometry showed an apparently increased positive rate 76.2% for the platelet of the patient, compared with that of 31.9% for the control. From the comparative study of the platelet agglutination of the platelet rich plasma (PRP) derived from the citrated-added complete blood taken from the patient to whom Ticlopidine was given, added with adenosine-5'-diphosphate (ADP), collagen or acetyl glyceryl ether phosphoryl choline (AGEPC) as the reagents and that of normal control, it was shown that for AGEPC increased. Thus, increased reaction specific to AGEPC in addition to activated platelet was demonstrated in the present study.

Aged↗
PubMed1988

Regulated expression of a gene encoding a nuclear factor, IRF-1, that specifically binds to IFN-beta gene regulatory elements.

Expression of the interferon-beta (IFN-beta) gene is induced by a variety of agents, including viruses. Evidence has been provided that a mouse nuclear factor, termed interferon regulatory factor-1 (IRF-1), specifically binds to the upstream regulatory region of the human IFN-beta gene and mediates virus-induced transcription of the gene. In this study, we describe the molecular cloning and characterization of the mouse and human cDNAs encoding IRF-1. Our results suggest that IRF-1 is also involved in the regulation of other genes such as IFN-alpha and MHC class I genes. Surprisingly, IRF-1 gene expression is dramatically induced by Newcastle disease virus in mouse L929 cells and by Concanavalin A in spleen cells. We show here that the IRF-1 gene possesses virus-inducible promoter.

Amino Acid Sequence↗
PubMed1988

Decrease in the level of poly(ADP-ribose) synthetase during nerve growth factor-promoted neurite outgrowth in rat pheochromocytoma PC12 cells.

We have studied the changes in the levels of the enzyme molecule and mRNA for poly(ADP-ribose) synthetase during nerve growth factor-promoted neurite outgrowth in rat pheochromocytoma PC12 cells. When the PC12 cells were cultured in the presence of nerve growth factor, the content of enzyme molecules decreased along with neurite outgrowth to 50% of the original amounts in 2 days and the content of mRNA for the enzyme also decreased to approximately 50% in 2 days. These results suggest that the decrease of the enzyme molecule may be due to depression of expression of the gene for synthetase during the process. Taken together with previous observations, the decrease of the synthetase seems to be required for some cellular differentiation.

Adrenal Gland Neoplasms↗
PubMed1988

Cloning and expression of the human interleukin-6 (BSF-2/IFN beta 2) receptor.

Interleukin-6 (IL-6/BSF-2/IFN beta 2) is a multifunctional cytokine that regulates the growth and differentiation of various tissues, and is known particularly for its role in the immune response and acute phase reactions. A complementary DNA encoding the human IL-6 receptor (IL-6-R) has now been isolated. The IL-6-R consists of 468 amino acids, including a signal peptide of approximately 19 amino acids and a domain of approximately 90 amino acids that is similar to a domain in the immunoglobulin (Ig) superfamily. The cytoplasmic domain of approximately 82 amino acids lacks a tyrosine/kinase domain, unlike other growth factor receptors.

Amino Acid Sequence↗
PubMed1988

Depression in gene expression for poly(ADP-ribose) synthetase during the interferon-gamma-induced activation process of murine macrophage tumor cells.

A 2.7-kb cDNA clone coding for bovine poly(ADP-ribose) synthetase was isolated from a lambda gt11 expression library by direct immunological screening with an antiserum to the enzyme. The cDNA hybridizes to an approximately 3.8-kb bovine thymus polyadenylated RNA, which translates an immunoprecipitable 120-kDa protein with the antibody to the enzyme. The partial DNA sequence of the cDNA was determined and portions of the predicted amino acid sequence matched the sequence of 26 amino acids at the N terminal of the 41-kDa alpha-chymotryptic fragment and two cyanogen-bromide-cleaved peptides of the enzyme. A subcloned fragment from the coding region of the cDNA was used as a probe to estimate the level of mRNA for the enzyme during the interferon-gamma-induced activation process of the murine macrophage tumor P388D1 cell line. The amount of mRNA for the enzyme decreased nearly completely within 24 h after incubation in a medium containing interferon-gamma, while mRNA of the Ia antigen, one of the major histocompatibility gene products, was increased in the macrophage tumor cells by interferon-gamma as confirmed by the I-A beta cDNA as a probe. These results suggest that the gene expression for poly(ADP-ribose) synthetase is depressed during the interferon-gamma-induced activation process of macrophage tumor cells.

Amino Acid Sequence↗
PubMed1988

Nicotinic acetylcholine receptors in the rat stomach: I. (-)-[3H]nicotine binding.

The nicotinic acetylcholine receptors in the rat stomach were characterized by means of a radioligand binding assay with (-)-[3H]nicotine as ligand. Saturation binding studies on the gastric fundus membranes revealed the presence of two binding sites with dissociation constant (KD) values of 3.1 and 289 nM, and maximum binding capacity (Bmax) values of 3.6 and 76 fmol/mg protein, respectively. The Bmax of the high affinity binding site was greatest in the cardia, followed by fundal mucosa, fundal muscle, and, finally antrum. The IC50 values of cholinergic drugs to inhibit (-)-[3H]nicotine binding in fundus membranes were as follows: (-)nicotine, 0.12 nM; cytosine, 9.3 nM; acetylcholine, 17.7 nM; carbachol, 700 nM; hexamethonium, 2270 nM. The IC50 values of alpha-bungarotoxin, d-tubocurarine and atropine were greater than 100 microM. The muscarinic acetylcholine receptors were also characterized with [3H]quinuclidinyl benzilate and the choline acetyltransferase activity was measured. These results suggest that nicotinic acetylcholine receptors as well as muscarinic acetylcholine receptors are present in the rat stomach and that the regional distribution of these receptors is uneven.

Animals↗
PubMed1988

Nicotinic acetylcholine receptors in the rat stomach: II. Alterations after vagotomy.

Nicotinic and muscarinic acetylcholine receptors were studied in the stomach of vagotomized rats, with ligand binding techniques, and with the concomitant measurement of choline acetyltransferase (ChAT). The maximum binding capacity (Bmax) of the high affinity sites of (-)-[3H]nicotine binding was significantly increased in all the regions of the stomach of subdiaphragmatically vagotomized animals while the values for the low affinity sites remained the same as those in sham-operated animals. On the other hand, [3H]quinuclidinyl benzilate binding to the stomach was unchanged after vagotomy. ChAT activity was significantly reduced in the vagotomized rats. These results suggest that surgical vagal denervation causes an increase in the density of nicotinic acetylcholine receptors presumably located on the parasympathetic ganglion cells. There is also a reduction of ChAT activity, probably due to a degenerative loss of preganglionic cholinergic neurons. Preganglionic denervation (decentralization) has little influence on the muscarinic receptors of postsynaptic effector organs.

Animals↗
PubMed1988

Changes in benzodiazepine receptors in Alzheimer-type dementia.

We studied benzodiazepine receptors in brains obtained at autopsy from 7 normal controls and 7 patients with Alzheimer-type dementia, using 3H-flunitrazepam as a ligand. Compared with controls, 3H-flunitrazepam binding sites were significantly reduced in number in frontal and temporal cortex and hippocampus in the Alzheimer-type dementia brains. These results suggest that there are significant changes in the number of benzodiazepine receptors in selected brain regions of patients with Alzheimer-type dementia.

Aged↗
PubMed1988

Evidence for a nuclear factor(s), IRF-1, mediating induction and silencing properties to human IFN-beta gene regulatory elements.

Transcription of the human interferon-beta (IFN-beta) gene is induced by a variety of agents such as viruses, dsRNA and some cytokines. In this study, we describe a nuclear factor, termed interferon regulatory factor-1 (IRF-1), that is involved in the transcription of IFN-beta and possibly other genes. We demonstrate that IRF-1 functions in virus-induced transcription by interacting with previously identified, IFN-beta regulatory DNA elements. Our data suggest that IRF-1 participates in the transient formation of an induction-specific complex(es) with the regulatory elements. IRF-1 may also be involved in silencing the function of the SV40 enhancer juxtaposed to the regulatory elements in uninduced cells.

Animals↗
PubMed1988

Effects of hypoxia on contractile responses of rabbit aortic strips to transmural electrical stimulation.

To clarify the effects of hypoxia on adrenergic transmission, we examined the contractile responses of isolated rabbit aortic strips to electrical stimulation, the concentration-response relationships for noradrenaline and KCl, and the electrical stimulation-evoked overflows of total [3H] and [3H]noradrenaline from strips preloaded with [3H]noradrenaline in media equilibrated with gas mixtures containing various concentrations of O2. Contractile responses to electrical stimulation were completely inhibited by tetrodotoxin and alpha-adrenoceptor antagonists such as phentolamine and phenoxybenzamine, but were not affected by indomethacin. When the concentration of O2 in the gas mixture was decreased from 95% to 20%, the contractile responses to electrical stimulation remained unchanged, but as the concentration of O2 was further decreased, the responses were inhibited concentration-dependently. At 0% O2, the response was inhibited by about 80% when compared with control values obtained at 95% O2, and the electrical stimulation-evoked overflows of total [3H] and [3H]noradrenaline into the superfusates were decreased by about 55%. At 0% O2, the concentration-response curve for exogenous noradrenaline was shifted to the right about 50-fold and the maximum response was decreased by 25%. The maximum contractile responses of aortic strips from animals pretreated with reserpine or 6-hydroxydopamine to high KCl were decreased slightly (about 15%). These results suggest that inhibition of adrenergic transmission under hypoxic conditions is mainly the result of a decrease in the stimulus-evoked release of noradrenaline and of a decrease in the affinity of alpha-adrenoceptor for noradrenaline and/or inhibition of signal transduction mechanisms, although hypoxia also causes a slight decrease in the contractility of vascular smooth muscle.

Animals↗
PubMed1988

A case of ruptured duodenal varices and review of the literature.

The incidence of duodenal varices is exceedingly rare. A case of bleeding duodenal varices located in the third portion of the duodenum, secondary to idiopathic portal hypertension, which was successfully treated by surgery, is presented herein. Diagnosis was suspected at superior mesenteric angiography and was subsequently confirmed by endoscopy. A review of the literature reveals only 105 such cases in the world. While the duodenal bulb is the most common site of duodenal varices, the second portion of the duodenum appears to be the next most common site but duodenal varices in the other portions are extremely rare. From all of the possible causes of duodenal varices, liver cirrhosis remains the predominant etiological factor in 31 cases.

Duodenum↗
PubMed1988

Mesenteric arteriovenous shunt associated with thrombosis of the portal venous system: case report.

We report a rare case of mesenteric arteriovenous shunt associated with thrombosis of the portal venous system. The angiographic features consisted of new vessel formation, thrombosis of the main portal vein, superior mesenteric vein and branches, and early filling of distal mesenteric veins with hepatopetal collateral flow. This phenomenon may be due to new vessel formation within the portal vein thrombosis and active lysis of the thrombus exposing the organizing vessels to the distal superior mesenteric veins.

Arteriovenous Fistula↗
PubMed1988

The bindings of 3H-prazosin and 3H-yohimbine to alpha adrenoceptors in the guinea-pig stomach.

Alpha adrenoceptor subtypes have been investigated by radioligand binding study in guinea-pig stomach using 3H-prazosin and 3H-yohimbine. The specific 3H-prazosin binding to guinea-pig stomach was saturable and of high affinity (KD = 1.4 nM) with a Bmax of 33 fmol/mg protein. Specific 3H-yohimbine binding to the tissue was also saturable and of high affinity (KD = 25.5 nM) with a Bmax of 150 fmol/mg protein. Adrenergic drugs competed for 3H-prazosin binding in order of prazosin greater than phentolamine greater than methoxamine greater than norepinephrine greater than clonidine greater than epinephrine greater than yohimbine. These drugs competed for 3H-yohimbine binding in order of yohimbine greater than phentolamine greater than clonidine greater than epinephrine greater than norepinephrine greater than prazosin greater than greater than prazosin greater than methoxamine. We also examined whether dopamine receptors exist in guinea-pig stomach, using radioligand binding study. Specific binding of 3H-spiperone, 3H-apomorphine, 3H-dopamine and 3H-domperidone was not detectable in the stomach. Dopaminergic drugs such as dopamine, haloperidol, domperidone and sulpiride competed for 3H-prazosin binding in order of haloperidol greater than domperidone greater than dopamine greater than sulpiride. Metoclopramide, sulpiride and dopamine competed for 3H-yohimbine binding in order of metoclopramide greater than sulpiride greater than dopamine. These results suggest that guinea-pig stomach has alpha 1 and alpha 2 adrenoceptors and has no specific dopamine receptors. It is also suggested that some dopamine receptor antagonists such as domperidone, haloperidol, sulpiride and metoclopramide have antagonistic actions on alpha adrenoceptors.

Animals↗
PubMed1988

Cellular and genetic analyses of IL-2 production and IL-2 receptor expression in a patient with familial T-cell-dominant immunodeficiency.

Cellular and genetic analyses of interleukin-2 (IL-2) production and IL-2 receptor (IL-2R) expression were examined in a immunodeficient patient and his family members. Mononuclear cells (MNC) of the patient showed no proliferative response (stimulation index, less than 2) to T-cell mitogens (PHA and Con A) and were defective in IL-2 production and IL-2R expression (less than 1%), whereas productions of other lymphokines (B-cell differentiation factor and IFN-gamma) were not impaired significantly. His brother died of the same disease and his father also lacked in proliferative response and IL-2 production by PHA stimulation. In Southern blot analyses using DNA probes of IL-2 and IL-2R, patterns of the patient were the same as those of healthy volunteers, whereas the transcription of DNA coding for IL-2R to mRNA was lacking in the patient. These results suggest that inheritant defects of IL-2 production and IL-2R expression reside in this family and the defects are not linked to DNAs coding for IL-2 and IL-2R but to a transcriptional deficiency.

Concanavalin A↗
PubMed1988

Increased binding of [3H]muscimol and [3H]flunitrazepam in the rat brain under hypoxia.

We examined the effects of in vivo hypoxia (10% O2/90% N2) on the gamma-aminobutyric acid (GABA)/benzodiazepine receptors and on glutamic acid decarboxylase (GAD) activity in the rat brain. Male Wistar rats were exposed to a mixture of 10% O2 and 90% N2 in a chamber for various periods (3, 6, 12, and 24 h). The control rats were exposed to room air. The brain regions examined were the cerebral cortex, striatum, hippocampus, and cerebellum. GABA and benzodiazepine receptors were assessed using [3H]muscimol and [3H]flunitrazepam, respectively. Compared with control values, GAD activity was decreased significantly following a 6-h exposure to hypoxia in all four regions studied. On the other hand, the numbers of both [3H]muscimol and [3H]flunitrazepam binding sites were increased significantly. The increase in receptor number tended to return to control values after 24 h. Treatment of the membrane preparations with 0.05% Triton X-100 eliminated the increase in the binding capacity. These results may represent an up-regulation of postsynaptically located GABA/benzodiazepine receptors corresponding to the impaired presynaptic activity under hypoxia.

Animals↗