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T Takeda

Publications and source records attributed to T Takeda.

At least 667 records · Page 37Linked to original sources
PubMed1993

The gene encoding the heat-stable enterotoxin of Vibrio cholerae is flanked by 123-base pair direct repeats.

The heat-stable enterotoxin (O1-ST) gene (sto) was cloned from chromosome of the strain GP156 of Vibrio cholerae O1 (Inaba, El Tor) in Escherichia coli K-12, and its nucleotide sequence was determined. The nucleotide sequence of sto was very similar to that of NAG-ST gene (stn) of V. cholerae non-O1. Both sto and stn were flanked by 123-base pair direct repeats which had at least 93% homology to one another and included some inverted repeats. All the strains of V. cholerae, V. mimicus, V. metschnikovii, V. hollisae and Yersinia enterocolitica examined by colony hybridization had the direct repeat sequence regardless of ST-gene possession.

Amino Acid Sequence↗
PubMed1993

Identification of heat-stable enterotoxin-producing strains of Yersinia enterocolitica and Vibrio cholerae non-O1 by a monoclonal antibody-based enzyme-linked immunosorbent assay.

Using a mouse monoclonal antibody (MAb) 2F raised against Vibrio cholerae non-O1 heat-stable enterotoxin (NAG-ST) which also recognizes a shared epitope of Yersinia enterocolitica heat-stable enterotoxin (Y-ST), a competitive enzyme-linked immunosorbent assay (ELISA) was developed for independent detection of NAG-ST and Y-ST. There was good concordance between the Y-ST ELISA and the suckling mouse assay (SMA) for detection of Y-ST from test strains of Y. enterocolitica, and the Y-ST ELISA can effectively replace the SMA for routine detection of Y-ST. On the contrary, evaluation of the NAG-ST ELISA and the SMA using 139 strains of V. cholerae non-O1 showed discordant results and this was attributed to the presence of the suckling mice active factor(s) such as El Tor hemolysin and to the production of low amounts of NAG-ST. Concentration of culture supernatants of V. cholerae non-O1 followed by heating at 100 C was essential to obtain reproducible results by both the NAG-ST ELISA and the SMA. The ELISA developed in this study can be used for the identification of biologically active strains. While recently genetic methods such as polymerase chain reaction became available and were very reliable and simple techniques, the ELISA in this study has an advantage in detecting biologically toxic gene products of the strains. The genetic methods cannot differentiate silent STa genes which we often encounter in the case of Y. enterocolitica.

Animals↗
PubMed1993

A cancer-reactive human monoclonal antibody derived from a colonic cancer patient treated with local immunotherapy.

A human monoclonal antibody, YJ-37 (IgM) was generated through the fusion of human B lymphoblastoid cell line HO-323 with the regional lymph node lymphocytes from a colonic cancer patient who was treated with a local immunotherapy. This antibody was purified and conjugated with biotin, after which direct immunohistochemical staining was performed. The results revealed that YJ-37 selectively reacted with colonic cancer (7/19), gastric cancer (3/6), endometrial cancer (1/2) and colonic adenoma (7/13), but not with normal epithelia. Membrane immunofluorescence and FACS analysis also showed that YJ-37 bound to tumor cell surfaces. Furthermore, the chemical structure of the antigen defined by YJ-37 was analyzed by means of thin-layer chromatography immunostaining and ELISA. The results indicated that YJ-37 reacted with sialylated lacto-series carbohydrate chains, which have been reported to accumulate in cancer cells.

Adenoma↗
PubMed1993

Spontaneous amyloidosis in senile NSY mice.

Senile Nagoya, Shibata, Yasuda (NSY) mice developed amyloidosis and died from renal failure as a result of amyloidosis. NSY mice were first reported as experimental congenital diabetic mice by Shibata et al. in 1980. This study questioned whether NSY mice died from diabetic nephropathy. The authors of the present study investigated the life span and cause of death in these mice. The life span of NSY mice was found to be 618.7 +/- 72.5 days. NSY mice that lived for more than 400 days showed rising blood urea nitrogen and large amounts of amyloid deposits in the glomerulus of the kidneys. NSY mice died of renal amyloidosis. Immunological methods revealed that AApoAII was evident in the amyloid deposits of NSY mice. Apart from the kidneys, amyloid deposition was also found in the tongue, esophagus, stomach, small intestine, large intestine, rectum, lung, heart and adrenal glands. Amyloid deposits were found to a slight degree in the liver and the spleen. The most dominant amyloid deposition in NSY mice was seen in the glomerulus of the kidneys. From the point of view of amyloid depositional distribution, NSY mice were unique compared with other spontaneous amyloid mice.

Amyloidosis↗
PubMed1993

Cooperative studies on diarrheal diseases.

Enteric infection still causes the highest global morbidity and mortality in children under 5 years old. While there have been impressive developments in the early treatment of diarrhea, adequate diagnostic techniques are not yet available. An international collaboration was conducted with the National Institute of Cholera and Enteric Diseases, Calcutta on the rapid diagnosis and prevention of diarrheal diseases. Forty to fifty per cent of the 780-bed Infectious Diseases Hospital is occupied by cases of diarrhea. Vibrio cholerae O1 continues to occupy a prominent position, and the prevalence in children up to 2 years is 30.9%. Accordingly, immuno-enzymatic detection of cholera toxin in stool was achieved. Bead enzyme-linked immunosorbent assay (ELISA) could successfully detect 40 pg/mL toxin within 4 h, but the detection rate of culture, bead ELISA and polymerase chain reaction (PCR) method was 72.2, 71.1 and 95.9%, respectively, indicating that PCR provides the most sensitive and specific assay for diagnosis of cholera directly from the stool of patients. Heat-stable enterotoxin (STa) is another virulence factor of gastroenteritis. Various monoclonal antibodies were established against it, and developed a competitive ELISA for the detection of STa producing strains. A DNA probe was also prepared, and genus vibrio was monitored. V. mimicus were found to be the reservoirs of STa among clinical vibrios. Various monoclonal antibodies against STa were also useful for the epitope mapping, providing information on the topology of toxin-host interaction.

Cholera↗
PubMed1993

[Sporadic case of hemolytic uremic syndrome associated with verotoxin producing Escherichia coli O2:K1:H7].

Cases of enterohaemorrhagic Escherichia coli (EHEC) are being increasingly reported in Japan. Bacteriological isolation of EHEC has been a constant problem because the organism is shed for a short duration after onset on illness and generally during the prodromal stages. In order to ease the diagnosis of EHEC infections in this country, we have developed a LPS-based solid phase enzyme linked immunosorbent assay for serological diagnosis of the infection. Adequate knowledge on the prevalence of EHEC serogroups in Japan is mandatory for the success of such a diagnostic test. O157 is currently the prominent serogroup associated with EHEC infections in Japan followed by O111, O26 and O128 in that order of prevalence. In February 1992, a 1 year-old infant developed hemolytic uremic syndrome (HUS) 15 days later the prodrome of watery diarrhoea. Stool sample obtained on day 15 was cultured for detection of EHEC. Ten colonies of E. coli picked from MacConkey agar plate were examined by the polymerase chain reaction (PCR) using primers specific for both verotoxins (VT1 and VT2). Of the 10 colonies, only one was positive for the VT2 gene. The strain was confirmed to be cytotoxic on cultured Vero cells. The strain agglutinated with antisera of E. coli O2, K1 and with H7 serogroups. As of date, none of such strains of O2:K1:H7 EHEC has been reported in Japan. The patient's sera was found to be positive for antibodies against LPS from the homologous isolate as well as against VT2. The patient recovered uneventfully from HUS 40 days after the onset of the disease and was discharged from the hospital.

Antibodies, Bacterial↗
PubMed1993

[A healthy carrier of verotoxin-producing Escherichia coli, who was detected by periodic feces examinations].

Verotoxin-producing Escherichia coli (VTEC) was rapidly detected by the PCR method in one of the 9 feces samples. They were collected from the people who had been cooking meals for patients on a periodic feces examination on November 25, 1992. It was confirmed by PCR that the isolate had both VT1 and VT2vh toxic genes and showed cytotoxicity on Verocells. In this case, the isolate was highly susceptible to common antibiotic agents, it was removed by the administration of tosfulaxacin. Some isolates which had the same properties as those of the strain described in "VITEK GNI card" and the antimicrobial susceptibility and VT toxin types, were detected in 2 of the 3 members of her family, they were healthy carriers and did not have any subjective symptoms such as diarrhea or abdominal pain. In order to detect Verotoxic genes, the sample of feces preincubated for 3 h in trypticase broth was subjected to PCR. We recommend that this method is much more useful because of rapid detection and identification of VTEC compared with the classical culture method.

Adult↗
PubMed1993

Epitope mapping and characterization of antigenic determinants of heat-stable enterotoxin (STh) of enterotoxigenic Escherichia coli by using monoclonal antibodies.

A panel of monoclonal antibodies (MAbs) specific for the heat-stable enterotoxin (STh) of enterotoxigenic Escherichia coli was produced. All four MAbs (8G7, 53-4, 11C, and SH1) bound to native STh in an enzyme-linked immunosorbent assay to various degrees, with clone SH1 showing the best affinity. The MAbs were screened for neutralizing and guanylate cyclase-inhibiting activities by the suckling mouse assay and the cyclic GMP assay using T84 cells, respectively. The contact amino acid residues governing the reactivity of the four MAbs were precisely determined by using several chemically synthesized analogs of the various heat-stable enterotoxins (STa's). Three distinct antigenic sites of STh sufficiently removed from each other, one near the N terminus, another in the core functional region of the toxin, and the third in the C-terminal region, were recognized by the different MAbs. MAb SH1, which recognized Asn at position 4 and Tyr at position 5 from the N terminus was 100 times more potent in neutralizing the bioactivity of STh in the suckling mouse assay than was MAb 11C, which recognized Thr at position 16 and Tyr at position 19 from the N terminus of the STh molecule. The MAbs which recognized Leu at position 9 from the N terminus (MAb 53-4) and Tyr at position 19 from the N terminus (MAb 8G7) showed intermediate activities in the neutralization assay. The guanylate cyclase-inhibiting activities of SH1 and 11C essentially paralleled the results for the neutralization of bioactivity, while MAbs 53-4 and 8G7 exhibited reverse activity. These results indicate that MAbs that recognize the N-terminal residues which have been shown not to be essential for toxic activity have a potent protective capacity. None of the MAbs reacted with reduced and carboxy-methylated native STh. This suggests that all of the MAbs mediate their effect by reacting with conformation-dependent antigenic determinants.

Amino Acid Sequence↗
PubMed1993

Assessment of enterotoxin production by Yersinia enterocolitica and identification of a novel heat-stable enterotoxin produced by a noninvasive Y. enterocolitica strain isolated from clinical material.

Twenty-eight clinical isolates of Yersinia enterocolitica were investigated for their abilities to produce heat-stable enterotoxin (YST). All 21 invasive strains (serogroup O3 biotype 4) carried the previously described gene for YST (yst), with toxin detectable in culture supernatants from 20 strains. One of seven noninvasive, biotype 1A strains also had enterotoxic activity, despite failure to hybridize with a probe for yst. The toxin produced by this noninvasive (serogroup O6) strain resembled YST in terms of molecular size, heat stability, and solubility in methanol. It differed from YST, however, with respect to regulation of its production by temperature and its mechanism of action, which did not appear to involve cyclic GMP.

Animals↗
PubMed1993

Detection of cholera toxin gene in stool specimens by polymerase chain reaction: comparison with bead enzyme-linked immunosorbent assay and culture method for laboratory diagnosis of cholera.

Stool specimens obtained from 123 hospitalized patients with acute secretory diarrhea admitted to the Infectious Diseases Hospital, Calcutta, India, were examined for isolation of Vibrio cholerae O1 by direct or enrichment plating on selective media for cholera toxin (CT) by bead enzyme-linked immunosorbent assay (bead-ELISA) and for the CT gene by polymerase chain reaction (PCR). V. cholerae O1 was isolated either by direct culture or by enrichment culture from 70 stool specimens, all of which gave positive results by PCR. Eleven specimens which were culture negative and bead-ELISA positive also gave positive results by PCR. In addition, 13 more specimens which were negative by both the culture method and bead-ELISA, were positive by PCR. With the combined results of both the culture method and the CT bead-ELISA, a confirmed laboratory diagnosis of cholera could be made from 81 stool specimens, while the combined results of the three methods, including PCR, yielded a positive result for 94 specimens examined. From these data, we conclude that PCR provides a more sensitive and specific assay for rapid diagnosis of cholera than currently available methods.

Adult↗
PubMed1993

Identification of a novel interleukin-6 response element containing an Ets-binding site and a CRE-like site in the junB promoter.

Interleukin-6 (IL-6) activation of the immediate-early gene junB has been shown to require both a tyrosine kinase and an unknown 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7)-sensitive pathway. Here we report the identification and characterization of an IL-6 immediate-early response element in the junB promoter (designated JRE-IL6) in HepG2 cells. The JRE-IL6 element, located at -149 to -124, contains two DNA motifs, an Ets-binding site (EBS) (CAGGAAGC) and a CRE-like site (TGACGCGA). Functional studies using variously mutated JRE-IL6 elements showed that both motifs were necessary and sufficient for IL-6 response of the promoter. The EBS of the JRE-IL6 element (JEBS) appears to bind a protein in the Ets family or a related protein which could also form a major complex with the EBSs of the murine sarcoma virus long terminal repeat or human T-cell leukemia virus type 1 long terminal repeat. The CRE-like site appears to weakly bind multiple CREB-ATF family proteins. Despite the similarity in the structure between the JRE-IL6 element and the polyomavirus enhancer PyPEA3, composed of an EBS and an AP1-binding site and known to be activated by a variety of oncogene signals, JRE-IL6 could not be activated by activated Ha-Ras, Raf-1, or 12-O-tetradecanoylphorbol-13-acetate. We show that IL-6 activates JRE-IL6 through an H7-sensitive pathway that does not involve protein kinase C, cyclic AMP-dependent kinase, Ca(2+)- or calmodulin-dependent kinases, Ras, Raf-1, or NF-IL6 (C/EBP beta). The combination of JEBS and the CRE-like site appears to form the basis for the selective and efficient response of JRE-IL6 to IL-6 signals, but not to signals generated by activated Ha-Ras, Raf-1, or protein kinase C.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Significance of enzyme linked immunosorbent assay (ELISA) for antibodies to double stranded and single stranded DNA in patients with lupus nephritis: correlation with severity of renal histology.

The correlation between renal histology and class specific (IgG and IgM) antibodies to double stranded DNA (dsDNA) and single stranded DNA (ssDNA) was studied by enzyme linked immunosorbent assay (ELISA) in 40 untreated patients with systemic lupus erythematosus (SLE). The levels of IgG antibodies to dsDNA were significantly higher in patients with World Health Organisation class IV nephritis than in those with class I, class II, or class III nephritis. IgG antibodies to ssDNA were higher in patients with class IV than in those with class II nephritis. IgG antibodies to dsDNA showed a close correlation with the histological activity score and the amount of electron dense deposit. IgG antibodies to ssDNA showed only a weak correlation with the renal histological activity score. IgM antibodies to dsDNA and IgM antibodies to ssDNA were not correlated with renal histological features. Patients with moderate to severe nephritis had a lower ratio of IgM antibodies to dsDNA to IgG antibodies to dsDNA than those with mild nephritis. These results indicate that the measurement of IgG antibodies to dsDNA is predictive in evaluating renal histological activity in patients with SLE.

Antibodies, Antinuclear↗
PubMed1993

Interaction of PDGF and natriuretic peptides on mesangial cell proliferation and endothelin secretion.

The present study examined the possible interaction of platelet-derived growth factor (PDGF) and atrial or brain natriuretic peptides (ANP and BNP, respectively) on cellular proliferation and secretion of endothelin-1 in cultured rat mesangial cells. PDGF increased cellular proliferation and endothelin-1 secretion. The protein kinase C (PKC) inhibitors, 1-(5-isoquinolinylsulfonyl)-2-methylpiperazine, staurosporine, and PKC inhibitor peptide, inhibited such stimulation. Rat ANP-(1-28) and rat BNP-45 exhibited clearly dose-related inhibition of PDGF-stimulated cellular proliferation and endothelin-1 secretion. This inhibition by ANP and BNP was paralleled by an increase in the cellular level of guanosine 3',5'-cyclic monophosphate (cGMP). Results indicate that PDGF stimulates cellular proliferation and endothelin-1 secretion in cultured rat mesangial cells by a mechanism probably involving activation of PKC and that ANP and BNP inhibit such stimulation through a cGMP-dependent process.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Interaction between a phorbol ester and dopamine DA1 receptors on vascular smooth muscle.

The interaction between dopamine DA1 receptors and a phorbol ester was studied to elucidate the role of protein kinase C in the response of this receptor. The in vitro binding of [3H]Sch 23390 to DA1 receptor sites on vascular smooth muscle cells was saturable. The extent of [3H]Sch 23390 binding to phorbol ester-treated cells was increased without any change in the dissociation constant. The production of adenosine 3',5'-cyclic monophosphate (cAMP) in response to DA1 receptor stimulation was enhanced by preincubation of vascular smooth muscle cells with the phorbol ester for 4 h. However, no enhancement was observed when the medium used for preincubation was supplemented with a protein kinase C inhibitor. Direct stimulation of stimulatory guanine nucleotide-binding regulatory protein with 5-guanylylimidodiphosphate and direct stimulation of adenylate cyclase with forskolin produced no significant differences in cyclase levels between phorbol ester-treated and untreated cells. These results suggest that activation of protein kinase C triggers an increase in the membrane expression of DA1 receptors, thereby enhancing receptor-coupled cAMP generation.

Adenylyl Cyclases↗
PubMed1993

Natriuretic peptides inhibit mesangial cell production of endothelin induced by arginine vasopressin.

The present study examined the effects of atrial, brain, and C-type natriuretic peptides (ANP, BNP, and CNP, respectively) on endothelin-1 (ET-1) secretion after stimulation with arginine vasopressin (AVP), using cultured rat glomerular mesangial cells. AVP stimulated immunoreactive (ir) ET-1 secretion in a concentration-dependent manner via a receptor-mediated process. Rat ANP-(1-28) and rat BNP-45 potently inhibited this stimulated secretion in a concentration-dependent manner. Inhibition by ANP and BNP of AVP-stimulated ET-1 secretion was paralleled by an increase in the medium level of guanosine 3',5'-cyclic monophosphate (cGMP). The addition of a cGMP analogue, 8-bromo-cGMP, reduced the stimulated ET-1 secretion. CNP was much less effective than rat ANP-(1-28) or rat BNP-45 with respect to inhibiting irET-1 secretion and increasing cGMP levels. High-performance liquid chromatography indicated that the major component of irET-1 in the culture medium corresponds to ET-1-(1-21). These findings indicate that AVP stimulates ET-1 secretion in cultured rat mesangial cells and that rat ANP and BNP inhibit this stimulated secretion, probably through a cGMP-dependent process.

Animals↗
PubMed1993

Angiographic-pathologic correlations after elective percutaneous transluminal coronary angioplasty.

BACKGROUND: The local effect of coronary angioplasty is evaluated on the basis of postangioplasty angiograms. Smooth-walled dilation is considered to represent minimal or no injury, whereas intraluminal haziness corresponds with wall laceration. This study correlates the preangioplasty and postangioplasty angiograms with the histopathology of the target sites. METHODS AND RESULTS: The study includes 12 patients, each undergoing an elective procedure, and covers 19 angioplasty sites. Smooth-walled dilation and intraluminal haziness were not mutually exclusive. The angiograms were interpreted as smooth-walled dilation (n = 3), smooth-walled dilation with intraluminal haziness (n = 4), intraluminal and extraluminal haziness (n = 5), extraluminal dissection (n = 5), spiraltype dissection (n = 1), and aneurysm (n = 1). The histology of the arterial segments revealed wall laceration in all. Smooth-walled dilation without intraluminal haziness correlated with laceration limited to the intima in two, but with medial injury in one. Smooth-walled dilation with intraluminal haziness correlated with laceration limited to the intima in two and with medial injury in two. Intraluminal and extraluminal haziness corresponded with extensive laceration with deep involvement of the media in each. Extraluminal dissection correlated with a dissection along the shoulder area of the plaque, creating a broad-based flap. The spiral-type dissection corresponded with a true dissection into the plaque-free media. The aneurysm correlated with partial washout of an atherosclerotic plaque. CONCLUSIONS: The angiographic image of intraluminal and extraluminal haziness indicates extensive medial laceration. Smooth-walled dilation, with or without intraluminal haziness, is not a reliable indicator. The study emphasizes the need to reconsider the interpretations of postangioplasty coronary angiograms.

Aged↗
PubMed1993

Heparin regulates endothelin production through endothelium-derived nitric oxide in human endothelial cells.

Heparin shows blood pressure lowering effect in hypertensive patients and animal models. The present study examined the effect of heparin on vasoconstrictor endothelin-1 (ET-1) production in cultured human umbilical vein endothelial cells (ECs) to elucidate the mechanism of antihypertensive effect of heparin. Heparin suppressed both basal and thrombin-stimulated ET-1 mRNA expression paralleled with a decrease in ET-1 peptide release in a dose-dependent manner. Heparin concomitantly enhanced nitric oxide (NO) formation measured by NO2/NO3 levels and cGMP production in ECs. These enhancements were more marked when ECs were stimulated by thrombin. However, these heparin's effects were blunted in the presence of endothelium-derived nitric oxide (EDNO) synthesizing inhibitor NG-monomethyl L-arginine. Therefore, these results suggest that suppression of ET-1 production by heparin is EDNO mediated.

Analysis of Variance↗