Search PubMed⌕ Search

Biomedical subjects

T Iida

Publications and source records attributed to T Iida.

At least 127 records · Page 7Linked to original sources
PubMed1999

Degranulation of eosinophilic granular cells with possible involvement in neutrophil migration to site of inflammation in tilapia.

Observations were made on stretched preparations from the swim bladder and peritoneum obtained from tilapia (Oreochromis niloticus) after injection of formalin-killed Escherichia coli, proteose peptone, compound 48/80 or HBSS into the swim bladder. The eosinophilic granular cells (EGCs) in the swim bladder degranulated rapidly after inoculation. However, the peritoneal EGCs did not degranulate, indicating that degranulation occurs only at the injected site. There was also a correlation between the ratio of the degranulated EGCs and number of the exudate neutrophils. Killed E. coli (1 mg/fish) produced the greatest degranulation response of EGCs and migration of neutrophils into the inflammatory site. Additionally, the rate of the degranulation and number of the neutrophils were lowest when HBSS was injected. The results of this study verify that degranulation of EGCs is involved in the neutrophil migration and suggest that fish EGCs are analogous to mammalian mast cells.

Air Sacs↗
PubMed1999

Melatonin induces gamma-glutamylcysteine synthetase mediated by activator protein-1 in human vascular endothelial cells.

In the present study, we show that melatonin induces the expression of gamma-glutamylcysteine synthetase (gamma-GCS), the rate-limiting enzyme of glutathione (GSH) synthesis, in ECV304 human vascular endothelial cells. One micromolar melatonin induced the expression of gamma-GCS mRNA followed by an increase in the concentration of GSH with a peak at 24 h. An electrophoretic mobility shift assay showed that melatonin stimulates the DNA-binding activity of activator protein-1 (AP-1) as well as retinoid Z receptor/retinoid receptor-related orphan receptor alpha (RZR/RORalpha). ECV304 cells transiently transfected with a plasmid containing the gamma-GCS promoter-luciferase construct showed increased luciferase activity when treated with melatonin. The melatonin-dependent luciferase activity was found in the gamma-GCS promoter containing AP-1 site. The luciferase activity mediated by AP-1 was repressed in the promoter containing RZR/RORalpha site. In addition, cell cycle analysis showed that melatonin increases the number of cells in the G0/G1 phase; however, treatment of the cells with buthionine sulfoximine, a specific inhibitor of gamma-GCS, abolished the effect of melatonin on the cell cycle, suggesting induction of cell arrest by melatonin requires GSH. As conclusion, induction of GSH synthesis by melatonin protects cells against oxidative stress and regulates cell proliferation.

Buthionine Sulfoximine↗
PubMed1999

Nucleotide sequences and characterization of genes encoding naphthalene upper pathway of pseudomonas aeruginosa PaK1 and Pseudomonas putida OUS82.

A 12,808-nucleotide containing DNA fragment cloned from naphthalene-utilizing (Nah+) Pseudomonas aeruginosa PaK1 was analyzed and compared with the genes (pah(OUS)) of a 14,462-nucleotide DNA fragment from Pseudomonas putida OUS82. The DNA sequence analyses demonstrated that the naphthalene upper-pathway genes and their deduced enzymes were very similar between the two bacteria: nucleotide similarities, 83-93%; amino acid similarities, 79-95%. These genes were also similar to those of the nah operon of plasmid NAH7; in particular, the OUS82 genes were similar to the nah genes, whereas the PaK1 genes were almost identical to the dox genes of Pseudomonas sp. C18. A region homologous with the 84-bp repeated sequence that Eaton (J. Bacteriol., 176, 7757-7762, 1994) has found at a site upstream of he nah operon was found only in a region downstream of the pah(PaK) gene cluster in PaK1 and on both sides of the pah(OUS) gene cluster in OUS82. A PaK1 gene, corresponding to an unknown gene (nahQ) in the nah operon, is located between the 1,2-dihydroxynaphthalene dioxygenase gene and the trans-o-hydroxybenzylindenepyruvate (tHBP A) hydratase-aldolase gene (nahE), and was suggested to be involved in the conversion of naphthalene to salicylate. Just downstream of the pah(PaK) gene cluster, a portion of a region was identical to one-third of the transposase gene (tnpA) in a phenol-catabolic plasmid pEST1226.

Journal Article↗
PubMed1999

Late development of antidesmoglein 1 antibodies in pemphigus vulgaris: correlation with disease progression.

The coexistence of antidesmoglein 3 (Dsg3) and antidesmoglein 1 (Dsg1) autoantibodies is well described in patients with pemphigus vulgaris (PV); however, there is little evidence of sequential development of these two autoantibodies. Autoantibody responses to Dsg3 and Dsg1 were studied in seven PV patients over time by enzyme-linked immunosorbent assay, using baculovirus expressed recombinant fusion proteins. All patients had anti-Dsg3 IgG antibodies at presentation. Two patients developed anti-Dsg1 later in the course of the disease. The transition in autoantibody profile was associated with disease progression to generalized PV involving mucous membranes and skin in both patients; one patient initially presented with a predominantly mucosal phenotype, the other with herpetiform pemphigus-like features. These findings demonstrate that there is an extension of autoimmune response from anti-Dsg3 only to both anti-Dsg3 and anti-Dsg1 in some patients, which is associated with an alteration in clinical expression in PV.

Adult↗
PubMed1999

Physical and genetic map of the genome of Vibrio parahaemolyticus: presence of two chromosomes in Vibrio species.

We constructed a physical map of the genomic DNA (5.1 Mb) for Vibrio parahaemolyticus strain AQ4673 by combining 17 adjacent NotI fragments. This map shows two circular replicons of 3.2 and 1.9 Mb. Pulsed-field gel electrophoresis (PFGE) of undigested genomic DNA revealed two bands of corresponding sizes. Analysis both by NotI digestion and by Southern blot of the two isolated bands confirmed the existence of two replicons. The presence of genes for 16S rRNA on both the replicons indicates that the replicons are chromosomes rather than megaplasmids. The two bands were also seen after PFGE of undigested genomic DNA of V. parahaemolyticus strains other than AQ4673, and of strains belonging to other Vibrio species, such as V. vulnificus, V. fluvialis and various serovars and biovars of V. cholerae. It is noteworthy that V. cholerae O1 strain 569B, a classical biovar, was also shown to have two replicons of 2.9 and 1.2 Mb, which does not agree with a physical map proposed in a previous study. Our results suggest that a two-replicon structure is common throughout Vibrio species.

Chromosome Mapping↗
PubMed1999

An analysis of T cell antigen receptor variable beta genes during the clinical course of patients with chronic hepatitis B.

BACKGROUND: The degree of hepatocyte injury in patients with chronic hepatitis B appears consistent with the number of T cells that respond to hepatitis B virus-related antigens. METHODS: By using a polymerase chain reaction (PCR)-based approach, we monitored a ratio of the T cell antigen receptor (TcR) variable (V) beta gene families against a total TcR V beta gene expression in the peripheral T cells obtained from five patients and four healthy controls. RESULTS: In the healthy controls, there was no significant change in the ratios at an interval of four or eight weeks. In contrast, several TcR V beta families showed the significant changes in the ratios of their gene expression during the follow-up period in all patients. No common highly fluctuated TcR V beta, however, was found among the patients. Furthermore, there was no correlation between their changes and serum levels of alanine aminotransferase. CONCLUSIONS: These findings suggest that the skewing of the TcR family with multiclone is the result of T-cell responses to viral antigens in peripheral blood.

Adult↗
PubMed1999

Regulation of gamma-glutamylcysteine synthetase expression in response to oxidative stress.

Glutathione (GSH) is synthesized by the activity of two ATP-requiring GSH synthesizing enzymes. Gamma-glutamylcysteine synthetase (gamma-GCS) is the rate limiting enzyme for the GSH synthesis. Gamma-GCS is a heterodimer of heavy, catalytic subunit and light, regulatory subunit and responsive to many stresses, such as heat shock, oxidative stress or cytokines. To know the regulation of the expression of gamma-GCS gene, in the present study, we show evidences that gamma-GCS heavy subunit is upregulated by oxidative stress by ionizing radiation and TNF-alpha mediated by nuclear factor-kappaB (NF-kappaB), and impairment of the expression of gamma-GCS by TNF-alpha in diabetic condition. Furthermore we describe the importance of GSH in the regulation of NF-kappaB subunits.

Animals↗
PubMed1999

Overexpression of glutathione S-transferase pi enhances the adduct formation of cisplatin with glutathione in human cancer cells.

In this paper, we provide direct evidence that glutathione S-transferase pi (GSTpi) detoxifies cisplatin (CDDP). We used human colonic cancer HCT8 cells sensitive and resistant to CDDP, the level of cisplatin-glutathione adduct (DDP-GSH) being higher in the resistant cells. There was an overexpression of GSTpi mRNA in these CDDP-resistant cells. Incubation of the cells with CDDP resulted in the formation of DDP-GSH dependent on the CDDP concentration and the incubation time. The formation of DDP-GSH was abolished when the cells were pre-treated with ethacrynic acid or ketoprofen, inhibitors of GSTpi. Purified GSTpi also catalyzed the formation of DDP-GSH in vitro, with an apparent Km of 0.23 mM for CDDP and an apparent Vmax of 4.9 nmol/min/mg protein. The increase in DDP-GSH produced by GSTpi was linear with incubation time up to 3 h and optimal of pH 7.4. A GSTpi transfectant cell line was constructed in HCT8 cells using a pcDNA3.1 (-)/Myc-His B with an expression vector containing cDNA for GSTpi. Transfection of GSTpi cDNA into HCT8 cells resulted in an increase in the expression of GSTpi by 1.4-fold in parallel with an augmentation of the formation of DDP-GSH. These results suggest that GSTpi plays a role in the formation of DDP-GSH and the acquisition of resistance to CDDP in cancer cells.

Cisplatin↗
PubMed1999

Kinetics of cytokine production in the cornea and trigeminal ganglion of C57BL/6 mice after corneal HSV-1 infection.

To investigate the role of cytokines in the pathogenesis of acute herpetic keratitis (HK), we examined the kinetics of cytokine expression in the corneas and the trigeminal ganglia (TG) of C57BL/6Cr (B6) mice after herpes simplex virus type 1 (HSV-1) infection and observed the influence of the targeted disruption of interferon-gamma (IFN-gamma) gene on the clinical course of HK and/or viral clearance. Following corneal infection with HSV-1 Amakata strain, all corneas developed a typical dendritic keratitis. Quantitative analysis using enzyme-linked immunosorbent assay (ELISA) revealed that the expression of interleukin-1alpha (IL-1alpha), IL-5, IL-6, and IFN-gamma in corneas and TGs significantly elevated immediately after infection, peaked between days 2 and 7 postinfection (p.i.), and then diminished. One exception was IFN-gamma, whose expression significantly persisted in the TGs until day 30 p.i. An additional experiment using IFN-gamma-/- (gko) mice revealed that there was no significant difference in the peak level of viral replication in corneas and TGs between gko and B6 mice, although gko mice showed a significant delay of virus clearance in both corneas and TGs (p < 0.005) and higher mortality rate than B6 mice after HSV-1 infection (p < 0.01). These data suggest that the production of proinflammatory cytokines closely correlates with the pathogenesis of HK, and that IFN-gamma plays an important role in enhancing viral clearance from the cornea and TG.

Animals↗
PubMed1999

Cytokine expression and induction of acinar cell apoptosis after pancreatic duct ligation in mice.

To clarify the role of cytokines and acinar cell apoptosis in the pathogenesis of acute pancreatitis, we investigated the expression of intrapancreatic cytokines and apoptosis-related molecules in mice after pancreatic duct ligation (PDL). From day 1 or 3 after PDL, the expression of interleukin-1alpha (IL-1alpha), IL-1beta, IL-1 receptor antagonist, IL-6, IL-10, and tumor necrosis factor (TNF-alpha) mRNA were up-regulated in the pancreas, suggesting that these cytokines may be involved in the development of pancreatitis after PDL. Acinar cell apoptosis was observed in the pancreas at rates of 0.13 +/- 0.03, 1.32 +/- 0.38, and 0.86 +/- 0.23% on days 1, 3, and 7 after PDL, respectively. Significant increases in intrapancreatic mRNA levels of TNF-alpha, Fas ligand (FasL), and IL-1beta-converting enzyme (ICE) were observed from day 3 after PDL with the appearance of acinar cell apoptosis. The serum amylase activity peaked on day 1 after PDL and gradually decreased on days 3 and 7 after PDL. These results suggest that acinar cell apoptosis induced after PDL may modulate the progression of acute pancreatitis by reducing the release of digestive enzymes and may therefore be a host defense mechanism, and that acinar cell apoptosis after PDL may be mediated by the TNF-alpha and/or Fas/FasL and ICE system.

Amylases↗
PubMed1999

Redox regulation of the glucocorticoid receptor.

Redox regulation is currently considered as a mode of signal transduction for coordinated regulation of a variety of cellular processes. The transcriptional regulation of gene expression is also influenced by cellular redox state, most possibly through the oxido-reductive modification of transcription factors. The glucocorticoid receptor belongs to a nuclear receptor superfamily and acts as a ligand-dependent transcription factor. We demonstrate that the glucocorticoid receptor function is regulated via redox-dependent mechanisms at multiple levels. Moreover, it is suggested that redox regulation of the receptor function is one of dynamic cellular responses to environmental stimuli and plays an important role in orchestrated crosstalk between central and peripheral stress responses.

Amino Acid Sequence↗
PubMed1999

Chlorella accelerates dioxin excretion in rats.

We investigated the effects of Chlorella on fecal excretion of polychlorinated dibenzo-p-dioxin (PCDD) congeners and polychlorinated dibenzofuran (PCDF) congeners in Wistar rats administered the rice oil that caused Yusho disease, as a substitute for purified dioxin. The rats were fed 4 g of a control diet or a 10% Chlorella diet containing 0.2 mL of the rice oil once during the 5-d experimental period. The amounts of PCDD and PCDF congeners excreted in feces from d 1 to 5 in the group fed 10% Chlorella were 0.2-11.3 and 0.3-12.8 times greater (P < 0.05), respectively, than those of the control group. We then investigated the fecal excretion of PCDD and PCDF congeners from d 8 to 35 in rats administered 0.5 mL of the rice oil. Rats consumed the basal diet for 1 wk. After 1 wk, they consumed either the basal diet or the 10% Chorella diet. The fecal excretions of PCDD and PCDF congeners in the group fed 10% Chlorella were 0.3-3.4 and 0.5-2.5 times greater (most, P < 0.05), respectively, than those of the control group. Thus, the fecal excretions of PCDD and PCDF congeners were greater in rats fed Chlorella. These findings suggest that the administration of Chlorella may be useful in preventing gastrointestinal absorption and for promoting the excretion of dioxin already absorbed into tissues. Moreover, these findings suggest that Chlorella might be useful in the treatment of humans exposed to dioxin.

Animals↗
PubMed1999

An instrument for measuring equilibrium-equivalent 222Rn and 220Rn concentrations with etched track detectors.

To simultaneously measure both 222Rn and 220Rn progeny concentrations, a new type of portable integrating monitor with allyl diglycol carbonate (CR-39) plastic detectors was developed. The monitor gives the average equilibrium-equivalent 222Rn and 220Rn concentrations (EEC(RN) and EEC(Tn)) during sampling intervals. The detection efficiencies of the alpha particles were calculated by Monte Carlo method. The lower limits of detection for EEC(Rn) and EEC(Tn) are estimated to be 0.57 Bq m(-3) and 0.07 Bq m(-3) for 24 h continuously sampling at a flow rate of 0.8 L min(-1). The measuring results with the new type monitors were confirmed through intercomparison experiments. In a small survey, a rather high 220Rn progeny concentration with an average of 1.73 Bq m(-3) was observed in traditional Japanese dwellings with soil/mud plastered walls. On the other hand, a very high 232Th concentration in soil was reported in China. They suggested that there is a possibility of high 220Rn progeny concentration in both Japan and China.

Air Pollution, Indoor↗
PubMed1999

Persistent and bilateral choroidal vascular abnormalities in central serous chorioretinopathy.

BACKGROUND: To clarify the role of choroidal vascular abnormalities in central serous chorioretinopathy (CSC) in active stage, remission, and recurrence. METHODS: Indocyanine green angiography and fluorescein angiography were performed in 105 eyes (104 patients) with active CSC. Forty-six patients were followed up for 6 to 48 months (mean +/- standard deviation, 22.5 +/- 8.9 months) with repeated angiography (mean +/- standard deviation, 3.5 +/- 1.5 times). Indocyanine green angiography and fluorescein angiography also were performed during remission in all 46 eyes with CSC and during recurrent CSC in 6 eyes. Unaffected fellow eyes underwent angiographic examinations in all patients. RESULTS: In active CSC, indocyanine green angiography showed a choroidal filling delay (71%), venous dilation (61%), and focal choroidal hyperfluorescence (96%) surrounding leakage from the retinal pigment epithelium. Focal choroidal hyperfluorescence was present in unaffected areas of affected eyes (55%). The choroidal venous dilation (36%) and choroidal hyperfluorescence (62%) were noted even in unaffected fellow eyes. These choroidal abnormalities persisted during remission after leakage ceased throughout the follow-up period. In the six patients with recurrent CSC, new leakage developed in the areas of persistent choroidal hyperfluorescence. Central serous chorioretinopathy developed in the unaffected fellow eye in one of these six patients. CONCLUSION: Choroidal vascular abnormalities persist in both eyes even after leakage from the retinal pigment epithelium ceases. Central serous chorioretinopathy may recur in areas of choroidal vascular abnormalities.

Adult↗
PubMed1999

Pemphigus vulgaris preceded by herpetiform-like skin lesions with negative immunofluorescence findings.

We report a case of pemphigus vulgaris in a 63-year-old woman. At the first onset, she developed herpetiform-like skin lesions. Their histology showed eosinophilic spongiosis and intraepidermal blister formation with an infiltrate of eosinophils. Both direct and indirect immunofluorescence studies were negative. She remained in remission for 6 years. At the second onset, she developed bullous skin lesions; histological examination disclosed suprabasal acantholysis and infiltration of eosinophils. Direct immunofluorescence revealed IgG and C3 deposits at the cell surface, predominantly in the lower epidermis. Indirect immunofluorescence using normal human skin as a substrate demonstrated anti-cell surface IgG antibodies at a titer of 1:160. Immunoblot analysis showed that the patient's serum reacted only with a 130 kD protein. This case indicates that pemphigus vulgaris can follow herpetiform-like skin lesions with negative immunofluorescence findings after a long remission time.

Blotting, Western↗
PubMed1999

Increased sensitivity of cholera toxin detection by enzyme-linked immunosorbent assay with chemical immobilization of antibody onto nylon surface providing hydrophobicity.

We developed an improved method to chemically immobilize antibodies on a nylon surface using a styrene maleic anhydride copolymer having an aryl group, which provides hydrophobicity to the nylon surface. We applied it to a modified enzyme-linked immunosorbent assay (slip-ELISA) for the detection of cholera toxin (CT). The sensitivity of slip-ELISA for CT detection was 1,000 times higher than that of conventional methods of physical adsorption using polystyrene plates, and 10 times higher than that of the method of chemical immobilization using maleic anhydride methylvinyl ether copolymer.

Antibodies, Monoclonal↗
PubMed1999

Differentiation of a cell line of human cervical argyrophil small cell carcinoma to macrophage lineage cells.

To investigate the origin of argyrophil small cell carcinoma (ASCC) of the uterine cervix, we examined the influence of dibutyryl cyclic adenosine 3',5'-monophosphate (dB-cAMP), a known differentiation inducer, on the characteristics of an ASCC cell line, TC-YIK, which has been shown to be a useful in vitro experimental model of ASCC. In TC-YIK cells after treatment with dB-cAMP, two specific antigenic markers of macrophages, CD14 and human leukocyte antigen-DR, were detected by flow cytometric analysis. In addition, interferon-gamma mRNA was detected by reverse transcription-polymerase chain reaction and interferon-gamma protein was detected by ELISA. More than 90% of the cells stained positive for alpha-naphthyl butyrate esterase, 1% of the cells showed phagocytotic activity against Micrococcus lysodeikticus, and 22% of the cells had M. lysodeikticus adsorbed on their surface. Furthermore, granulocyte-macrophage colony stimulating factor accelerated the proliferation of TC-YIK cells. These results indicate that dB-cAMP promotes differentiation of ASCC cells to macrophages. In contrast, less than 10% of the cells showed stellate morphology, suggesting differentiation to neuronal cells after treatment with dB-cAMP, as reported previously. Thus, TC-YIK cells have been shown to differentiate both into macrophage lineage cells and neuronal cells, suggesting that ASCC originates from undifferentiated stem cells.

Adult↗