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T Taniguchi

Publications and source records attributed to T Taniguchi.

At least 73 records · Page 4Linked to original sources
PubMed2001

Respiratory and cardiovascular effects of WP-934 in guinea pigs.

WP-934 is a newly developed reversible thermo-setting in situ gelling ophthalmic solution containing timolol. We investigated the effects of WP-934 on the respiratory and cardiovascular systems in guinea pigs and compared them with those of the conventional ophthalmic solution of timolol. At 30 min after instillation of timolol 0.5%, the airway responsiveness to histamine was 4 times higher, and that to acetylcholine was 2.5 times higher, than that before instillation. At 30 min after instillation of WP-934 0.5%, in contrast, the increase in responsiveness to each drug was about half that seen with the conventional solution. Topical instillation of timolol 0.5% weakened the effects of salbutamol and aminophylline on bronchodilatation, while that of WP-934 0.5% had no effect on aminophylline-induced bronchodilatation and a weaker effect on salbutamol-induced bronchodilatation. Topical instillation of timolol 0.5% and WP-934 0.5% failed to show a significant effect on blood pressure but caused a 10 to 20% decrease in heart rate for at least 120 min after instillation. WP-934 appears to have less respiratory adverse effects than timolol, mainly due to its longer retention on the ocular surface and a consequent decrease in systemic absorption.

Acetylcholine↗
PubMed2001

Intraarterial infusion chemotherapy and radiotherapy with or without surgery for patients with locally advanced or recurrent breast cancer.

We analyzed response, side effects, and local control rates of a multimodal treatment consisting of intraarterial infusion chemotherapy (IAIC) and radiotherapy with or without surgery for patients with locally advanced or recurred breast cancer. Thirty-three patients, clinically diagnosed as stage IIB in 1, IIIA in 2, IIIB in 12, IV in 18, were treated from 1991 to 1998. Twenty-five were primary and eight were recurrent cases after surgery. IAIC started as initial treatment up to three times maximum. In most cases, doxorubicin 50 mg, cisplatin 50 mg, and mitomycin 10 mg were infused in the subclavian and/or internal mammary artery. After IAIC, patients in primary cases underwent radical mastectomy or breast conservation surgery, after radiotherapy at a total dose of 50 Gy/25 fractions/5 weeks with a boost of 10 Gy. In recurrent cases, a full dose of radiotherapy was delivered. Clinical objective and complete response rates were 78% and 9% after IAIC. Despite a high rate of residual positive margin (67%) or clinically residual carcinoma, local recurrence developed only in 2 patients (6%) and local control rates at 5 years were calculated as 89%. Bone marrow suppression was frequent, and skin vesiculation (15%) and ulceration (9%) were experienced after IAIC. Skin ulcer (6%), brachial plexus neuropathy (3%), and radiation pneumonitis (3%) occurred as late toxicity. IAIC was effective as an induction treatment and radiotherapy played a role of local control for patients with locally advanced or recurrent breast cancer.

Adult↗
PubMed2001

Ketamine inhibits endotoxin-induced shock in rats.

BACKGROUND: Cytokines and nitric oxide are believed to participate importantly in the pathogenesis of endotoxin-induced shock. Several investigators have documented that ketamine attenuates production of cytokines and nitric oxide in endotoxemia, but little is known concerning hemodynamic effects of the drug in this state. The objective of the current study was to assess the potential modifying effects of ketamine in endotoxemia. METHODS: The authors randomly assigned 40 rats to one of four equal groups: endotoxin alone, receiving Escherichia coli endotoxin (15 mg/kg, administered intravenously); saline control, receiving saline only; ketamine alone, receiving ketamine (10 mg x kg(-1) x h(-1), administered intravenously); pretreatment, with ketamine administration initiated before the endotoxin exposure; and posttreatment, with ketamine initiated 2 h after endotoxin. During the 5 h after endotoxin injection, hemodynamics, acid-base status, and plasma concentrations of tumor necrosis factor alpha and interleukin 6 were assessed in each group. RESULTS: Endotoxin injection produced progressive hypotension, metabolic acidosis, and a large increase in the plasma cytokine concentrations. This hemodynamic and cytokine responses to endotoxin were completely abolished in the pretreatment group and modestly suppressed in the posttreatment group. in the absence of endotoxin, ketamine did not modify these responses. CONCLUSION: Ketamine administration inhibited hypotension, metabolic acidosis, and cytokine responses in rats injected with endotoxin. The results suggest that judicious use of ketamine as an anesthetic agent may offer advantages in endotoxemia.

Animals↗
PubMed2001

Screening for mutations of Axenfeld-Rieger syndrome caused by FOXC1 gene in Japanese patients.

PURPOSE: Mutations in the forkhead transcription factor gene (FOXC1) have been recently shown to cause some cases of juvenile glaucoma associated with a variety of anterior-segment anomalies. The purpose of this study was to investigate the clinical features of Axenfeld-Rieger syndrome caused by FOXC1 mutations in Japanese patients. PATIENTS AND METHODS: After informed consent was obtained, genomic DNA was isolated from peripheral blood. The DNA-sequence changes were analyzed using single-strand conformation polymorphism analysis and automated sequencing in six Japanese probands with Axenfeld-Rieger syndrome. RESULTS: The authors identified four mutations: pedigree 1 (26-47ins22), 2 (Ile91Ser), 3 (286ins1), and 4 (Arg127His). Two pedigrees showed new mutations in FOXC1. In pedigrees 1,2, and 4, younger generations had iris hypoplasia with severe early-onset glaucoma, whereas their parents had posterior embryotoxon without glaucoma. Pedigree 3 had a single affected person with iris hypoplasia and posterior embryotoxon with a mild increase of intraocular pressure. CONCLUSION: Four different FOXC1 mutations were found in four of six Japanese pedigrees with Axenfeld-Rieger syndrome. This was a new mutation in two pedigrees that was not found in earlier generations. This study confirms that mutations in this gene cause maldevelopment of the anterior segment of the eye.

Adolescent↗
PubMed2001

Cytokine responses to recombinant cholera toxin B subunit produced by Bacillus brevis as a mucosal adjuvant.

We attempted to clarify the mechanism of the mucosal adjuvanticity of recombinant cholera toxin B subunit (rCTB), which is inherently uncontaminated with the holotoxin produced by Bacillus brevis and has a powerful mucosal adjuvant activity, on cytokine responses compared with that of cholera toxin (CT). rCTB had no ability to stimulate cyclic AMP formation in mouse peritoneal macrophages (Mphi). Cytokine production by non-immunized Mphi cultured with rCTB or CT and by the spleen cells of mice co-immunized intranasally with ovalbumin (OVA) and rCTB or CT was examined. rCTB alone did not induce interleukin (IL)-1alpha/beta or IL-6 production by Mphi, but combination of rCTB with lipopolysaccharide (LPS) enhanced both IL-1alpha/beta production. Conversely, CT plus LPS suppressed IL-1alpha/beta production more than LPS alone. Both rCTB and CT suppressed IL-12 secretion induced by interferon gamma (IFN gamma) plus LPS. IL-2, IL-4, IL-5, and IL-10 were secreted by mouse spleen cells restimulated with OVA after intranasal co-administration of OVA together with rCTB, and in response to CT, the same cytokines were secreted. The different effect of rCTB on Mphi from that of CT may mean a difference between the mechanisms of rCTB and CT during the early stage of an immune response.

Adjuvants, Immunologic↗
PubMed2001

Mechanism for maintenance of dominant T helper 1 immune responses in Lewis rats.

Lewis rats are prone to T helper (Th) 1 immune responses, whereas Brown Norway (BN) rats are susceptible to Th2 immune responses. Yet, the precise mechanism of induction of the different outcome between these two strains remained elusive. We investigated the expression levels of some cytokines, their receptors and accessory molecules responsible for the polarization of antigen-specific immune response into a predominant Th1 or Th2 profile in Lewis and BN rats. Lymph node (LN) cells collected from rats immunized with short ragweed (RW) were used directly or after stimulation in vitro with RW for 3 days. Expression of cytokines, their receptors and accessory molecules in these LN cells were tested by reverse transcriptase-PCR. Culture supernatant was used for ELISA to detect IL-12 protein. We observed clear differences between these strains in the expression of IL-12p40, which was high in LN cells of Lewis rats even before stimulation in vitro. In addition, a higher amount of IL-12 was present in the culture supernatant in Lewis rats. Upregulation of the expression of IL-12 receptor beta1, beta2, IFN-gamma receptor alpha and beta genes were more prominent in Lewis rats rather than BN rats. Furthermore, attenuated expression of CD40 and CD40 ligand by stimulation in vitro was noted only in BN rats. Changes in expression of these molecules by stimulation as well as higher basal level of IL-12p40 might have led to the activation of Th1 cells in Lewis rats.

Animals↗
PubMed2001

Gene cluster for assembly of pilus colonization factor antigen III of enterotoxigenic Escherichia coli.

The assembly of pilus colonization factor antigen III (CFA/III) of enterotoxigenic Escherichia coli (ETEC) requires the processing of CFA/III major pilin (CofA) by a prepilin peptidase (CofP), similar to other type IV pilus formation systems. CofA is produced initially as a 26.5-kDa preform pilin (prepilin) and then processed to a 20.5-kDa mature pilin by CofP which is predicted to be localized in the inner membrane. In the present experiment, we determined the nucleotide sequence of the whole region for CFA/III formation and identified a cluster of 14 genes, including cofA and cofP. Several proteins encoded by cof genes were similar to previously described proteins, such as the toxin-coregulated pili of Vibrio cholerae and the bundle-forming pili of enteropathogenic E. coli. The G+C content of the cof gene cluster was 37%, which was significantly lower than the average for the E. coli genome (50%). The introduction of a recombinant plasmid containing the cof gene cluster into the E. coli K-12 strain conferred CFA/III biogenesis and the ability of adhesion to the human colon carcinoma cell line Caco-2. This is the first report of a complete nucleotide sequence of the type IV pili found in human ETEC, and our results provide a useful model for studying the molecular mechanism of CFA/III biogenesis and the role of CFA/III in ETEC infection.

Amino Acid Sequence↗
PubMed2001

Pulsed-field gel electrophoresis in differentiation of erysipelothrix species strains.

We report here the first analysis of Erysipelothrix spp. using pulsed-field gel electrophoresis (PFGE). Seventy strains of Erysipelothrix spp. were analyzed. SmaI, AscI, and NotI were tested for the ability to cleave the DNA extracted from those strains, and among them, SmaI was the most reliable enzyme. Sixty-three distinct PFGE patterns were produced, and no DNA degradation was observed, allowing the identification of all of the strains. Based on these results and on those of a previous analysis using randomly amplified polymorphic DNA and ribotyping, PFGE with SmaI might be considered to be more sensitive than those methods and to be the best method for epidemiological studies of strains of this genus.

Animals↗
PubMed2001

Requirement of interaction of nectin-1alpha/HveC with afadin for efficient cell-cell spread of herpes simplex virus type 1.

We recently found a novel cell-cell adhesion system at cadherin-based adherens junctions (AJs), consisting at least of nectin, a Ca(2+)-independent homophilic immunoglobulin-like adhesion molecule, and afadin, an actin filament-binding protein that connects nectin to the actin cytoskeleton. Nectin is associated with cadherin through afadin and alpha-catenin. The cadherin-catenin system increases the concentration of nectin at AJs in an afadin-dependent manner. Nectin constitutes a family consisting of three members: nectin-1, -2, and -3. Nectin-1 serves as an entry and cell-cell spread mediator of herpes simplex virus type 1 (HSV-1). We studied here a role of the interaction of nectin-1alpha with afadin in entry and/or cell-cell spread of HSV-1. By the use of cadherin-deficient L cells overexpressing the full length of nectin-1alpha capable of interacting with afadin and L cells overexpressing a truncated form of nectin-1alpha incapable of interacting with afadin, we found that the interaction of nectin-1alpha with afadin increased the efficiency of cell-cell spread, but not entry, of HSV-1. This interaction did not affect the binding to nectin-1alpha of glycoprotein D, a viral component mediating entry of HSV-1 into host cells. Furthermore, the cadherin-catenin system increased the efficiency of cell-cell spread of HSV-1, although it also increased the efficiency of entry of HSV-1. It is likely that efficient cell-cell spread of HSV-1 is caused by afadin-dependent concentrated localization of nectin-1alpha at cadherin-based AJs.

Amino Acid Sequence↗
PubMed2001

IRF family of transcription factors as regulators of host defense.

Interferon regulatory factors (IRFs) constitute a family of transcription factors that commonly possess a novel helix-turn-helix DNA-binding motif. Following the initial identification of two structurally related members, IRF-1 and IRF-2, seven additional members have now been reported. In addition, virally encoded IRFs, which may interfere with cellular IRFs, have also been identified. Thus far, intensive functional analyses have been done on IRF-1, revealing a remarkable functional diversity of this transcription factor in the regulation of cellular response in host defense. Indeed, IRF-1 selectively modulates different sets of genes, depending on the cell type and/or the nature of cellular stimuli, in order to evoke appropriate responses in each. More recently, much attention has also been focused on other IRF family members. Their functional roles, through interactions with their own or other members of the family of transcription factors, are becoming clearer in the regulation of host defense, such as innate and adaptive immune responses and oncogenesis.

Animals↗
PubMed2001

[Rapid acid extrusion response triggered by alpha-1a adrenoceptor in CHO cells].

Using a microphysiometer with synchronized valve switching, we investigated real-time acid extrusion from CHO cells, in which human alpha-1a adrenoceptor (AR) is stably expressed, in response to noradrenaline (NA). The time course of the extracellular acidification rate after stimulation had two phases: in the first phase, it transiently reached a rate several times greater than the base rate with a peak at around 10 s, and in the second, it reached to 2 times the base rate and reached a plateau in 2 min. Both phases showed concentration-dependent increase of acidification rates in response to NA, but had distinct pEC50 values: 5.6 for the transient phase and 7.2 for the steady phase. HOE642, an inhibitor of Na(+)-H+ exchanger (NHE) 1, inhibited the acid extrusion response in a concentration-dependent manner. HOE642 had high pIC50 values (7.3) for inhibition of the transient phase response. In contrast, it revealed the presence of two components in the steady phase response: one had high pIC50 values (8.2) and the other had low pIC50 values (6.0). As Ca2+ was depleted, the transient phase disappeared, while the steady phase was not affected. These results suggest that alpha-1a AR drives two acid extrusion systems in CHO cells upon stimulation: one elicits the transient response that is largely mediated by a HOE642-sensitive and Ca(2+)-dependent NHE, presumably NHE1, and the other induces the steady acid extrusion that is mediated by NHE1 and another NHE that has low sensitivity to HOE642.

Acids↗
PubMed2001

Affinity of serotonin receptor antagonists and agonists to recombinant and native alpha1-adrenoceptor subtypes.

Binding affinities of serotonin (5-HT)-receptor antagonists and agonists at human recombinant alpha1-adrenoceptor subtypes (alpha1a-, alpha1b- and alpha1d-subtypes) were examined and compared with the functional affinities obtained in rat caudal artery (alpha1A-subtype), dog carotid artery (alpha1B-subtype) and rat thoracic aorta (alpha1D-subtype). Most of the 5-HT-receptor antagonists and agonists tested showed relatively high affinity to three alpha1-adrenoceptor subtypes. The highest affinity close to 1 nM was seen for NAN-190 (5-HT1A antagonist) in binding and functional studies. 5-Methylurapidil (5-HT1A agonist) and BMY7378 (5-HT1A agonist) showed, respectively, alpha1a(alpha1A)- or alpha1d(alpha1D)-subtype selectivity in both binding and functional affinities, but spiperone (5-HT2A antagonist) showed alpha1b-selectivity only in binding affinity. Functional affinity of ritanserin (5-HT2A antagonist) to the alpha1B-subtype was approximately 500-fold lower than that of affinity to the alpha1b-subtype. The present results show that many 5-HT-receptor antagonists and agonists have high affinity to alpha1-adrenoceptors, but suggest that there is deviation between their functional affinities and binding affinities for some drugs.

Animals↗
PubMed2001

Newly established assay method for 25-hydroxyvitamin D3 24-hydroxylase revealed much lower Km for 25-hydroxyvitamin D3 than for 1alpha,25-dihydroxyvitamin D3.

An accurate assay method of 25-hydroxyvitamin D3 24-hydroxylase (24-hydroxylase) was established. Kidney mitochondria prepared from vitamin D-replete rats were treated with polyoxyethylenesorbitan monolaurate. The solubilized suspension was ultracentrifuged at 100,000g for 60 minutes and an aliquot of the supernatant was incubated under the saturating concentrations of substrate NADPH and the mitochondrial-type electron transferring proteins, adrenodoxin and NADPH-adrenodoxin reductase. Products were analyzed by high-performance liquid chromatography (HPLC) monitoring effluents at a wavelength of 265 nm. The maximal velocity of the enzyme in vitamin D-replete rats was 400 pmol/minute per mg of protein, which was considerably higher than those reported by previous authors who used intact kidney mitochondria as the enzyme source. In applying the new assay method, an interesting property was found; Michaelis constant of 24-hydroxylase for 25-hydroxyvitamin D3 [25(OH)D3] was 0.6 microM, which was 35-fold lower than that for 1alpha,25-dihydroxyvitamin D3 [1alpha,25(OH)2D3] which was 20.9 microM. This fact indicates that affinity of the enzyme to 25(OH)D3 is 35-fold higher than that to 1alpha,25(OH)2D3. These data suggest that 25(OH)D3 is the preferred substrate to 1alpha,25(OH)2D3.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed2001

Clinicopathological characteristics of left ventricular myocardium with transient asynergy: report of three cases.

The aim of the present retrospective study was to clarify the histopathologic substrates of left ventricular myocardium with transient asynergy due to acute ischemic insult in man. Three patients who had had prolonged chest pain, new abnormal Q waves and new ST segment elevation were studied. There was no significant elevation of serum creatine phosphokinase activity in two of the three patients. Echocardiograms on admission or the next day showed severe hypokinetic or akinetic motion and thinning of the anteroseptal and apical portions of the left ventricle and regional dilatation of the same portions. Disappearance of the abnormal Q waves, ST segment elevation resolution, and early T wave inversion were observed later. Complete improvement of the echocardiographic abnormalities was confirmed after a few weeks in all patients. Manifest ischemic lesions of subendocardial scars of the anteroseptal region of the left ventricle were detected in only one of the three cases by gross examination. However, on microscopic examination, islands of necrotic myocytes were interspersed with islands of viable cells throughout the jeopardized region in one case, although the scattered necrotic foci were restricted to the subendocardium and the trabeculae. Normal myocardium and subendocardial scars were observed in the other two cases. In conclusion, left ventricular myocardium with transient asynergy. detected clinically during acute ischemic attack, consists of normal myocardium or small ischemic lesions primarily in the subendocardium.

Aged↗
PubMed2001

Leptin stimulates rat aortic smooth muscle cell proliferation and migration.

Leptin, a peptide secreted from adipose tissue, plays an important role in the regulation of food intake and energy expenditure. In obese patients, plasma leptin levels are elevated and obesity is one of the major risk factors for cardiovascular diseases. Therefore, in this study, we investigated the effect of leptin on vascular smooth muscle cell (VSMC) functions. Cultured rat aortic VSMC expressed 130-kDa short form of leptin receptor. Leptin stimulated both proliferation and migration of VSMC. Leptin stimulated phosphorylation and activation of mitogen-activated protein (MAP) kinases, and also increased phosphatidylinositol (PI) 3-kinase activity. Further, two distinct PI 3-kinase inhibitors, wortmannin and LY294002 inhibited the migratory effect of leptin. These results demonstrate that leptin is a proliferative and migratory factor for VSMC, implying that leptin may play a role in the formation and development of vascular lesions.

Androstadienes↗