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N Furuya

Publications and source records attributed to N Furuya.

At least 37 records · Page 2Linked to original sources
PubMed2000

Initiation and termination of DNA transfer during conjugation of IncI1 plasmid R64: roles of two sets of inverted repeat sequences within oriT in termination of R64 transfer.

Intercellular transfer of plasmid DNA during bacterial conjugation initiates and terminates at a specific origin of transfer, oriT. We have investigated the oriT structure of conjugative plasmid R64 with regard to the initiation and termination of DNA transfer. Using recombinant plasmids containing two tandemly repeated R64 oriT sequences with or without mutations, the subregions required for initiation and termination were determined by examining conjugation-mediated deletion between the repeated oriTs. The oriT subregion required for initiation was found to be identical to the 44-bp oriT core sequence consisting of two units, the conserved nick region sequence and the 17-bp repeat A sequence, that are recognized by R64 relaxosome proteins NikB and NikA, respectively. In contrast, the nick region sequence and two sets of inverted repeat sequences within the 92-bp minimal oriT sequence were required for efficient termination. Mutant repeat A sequences lacking NikA-binding ability were found to be sufficient for termination, suggesting that the inverted repeat structures are involved in the termination process. A duplication of the DNA segment between the repeated oriTs was also found after mobilization of the plasmid carrying initiation-deficient but termination-proficient oriT and initiation-proficient but termination-deficient oriT, suggesting that the 3' terminus of the transferred strand is elongated by rolling-circle-DNA synthesis.

Bacterial Proteins↗
PubMed1999

Paradoxical synergistic effects of tumour necrosis factor and interleukin 1 in murine gut-derived sepsis with Pseudomonas aeruginosa.

The authors evaluated the synergistic effect of tumour necrosis factor (TNF) and interleukin 1 (IL-1) in gut-derived sepsis in mice. After colonization of Pseudomonas aeruginosa strain D4 in the gastrointestinal tract, cyclophosphamide was administered to induce bacterial translocation of the P. aeruginosa and thereby to cause gut-derived sepsis. In this model, treatment either with 8 microg/kg of recombinant human TNF-alpha (rhTNF-alpha) or 2 microg/kg of recombinant human interleukin 1alpha (rhIL-1alpha) solely did not affect the mortality, whereas combined administration of the same doses of rhTNF-alpha and rhIL-1alpha significantly increased the mortality rate in comparison with saline-treated mice. Bacterial counts in liver and blood were significantly higher in rhTNF-alpha and rhIL-1alpha treated mice than in saline-treated mice. Endogenous TNF-alpha and IL-1beta productions were stimulated after combined treatment with rhTNF-alpha and rhIL-1alpha. On the contrary to these adverse effects, combined treatment with 500 microg/kg of rhTNF-alpha and 50 microg/kg of rhIL-1alpha on the day before the administration of cyclophosphamide significantly reduced the mortality from septic infection. We conclude that TNF and IL-1 synergistically affect the mortality of mice after gut-derived sepsis due to P. aeruginosa in mice and the timing of treatment with these cytokines causes both extremes in their effects.

Animals↗
PubMed1999

Production of homo- and hetero-dimeric isozymes from two aldehyde oxidase genes of Arabidopsis thaliana.

Polyclonal antibodies were raised against synthetic peptides or recombinant polypeptides encoded by Arabidopsis atAO-1 and atAO-2 cDNAs, which have sequences similar to maize and animal aldehyde oxidase (AO) cDNAs. Anti-atAO-1 antibodies recognized AOalpha and AObeta among the three isoforms, AOalpha, AObeta, and AOgamma, detected in Arabidopsis seedlings after native PAGE, while anti-atAO-2 antibodies reacted with AObeta and AOgamma. The polypeptide specifically recognized by each antibody was collected as the Protein-A/IgG/antigen complex. The 150- and 145-kDa polypeptides were purified by SDS-PAGE and digested with Achromobacter Protease I. From the amino acid sequences and molecular masses of the derivative peptides, it was revealed that the 150- and 145-kDa polypeptides were the products of atAO-1 and atAO-2, respectively. Molecular masses of the native forms of AOalpha, AObeta, and AOgamma were estimated as approximately 290-300 kDa. These results suggest that AOalpha and AOgamma are homodimers consisting of atAO-1 and atAO-2 products, respectively, and that AObeta is a heterodimer of the atAO-1 and atAO-2 products.

Aldehyde Oxidase↗
PubMed1999

Fosfomycin alters lipopolysaccharide-induced inflammatory cytokine production in mice.

To determine the mechanisms of immunomodulating action of fosfomycin (FOF), we examined its effect on the production of inflammatory cytokines in mice injected with lipopolysaccharide (LPS). Treatment with FOF significantly lowered the peak serum levels of tumor necrosis factor alpha and interleukin-1 beta, indicating that FOF alters inflammatory cytokine production after LPS stimulation.

Animals↗
PubMed1999

Effect of antiflagellar human monoclonal antibody on gut-derived Pseudomonas aeruginosa sepsis in mice.

We evaluated the effect of antiflagellar human monoclonal antibody on gut-derived Pseudomonas aeruginosa sepsis. Mice were given a suspension of P. aeruginosa SP10052 in their drinking water and were simultaneously treated with ampicillin (200 mg/kg of body weight) to disrupt the normal bacterial flora. Cyclophosphamide was then administered to induce leukopenia and translocation of the P. aeruginosa that had colonized the gastrointestinal tract, thereby producing gut-derived generalized sepsis. In this model, intraperitoneal injection of 100 microg of antiflagellar human monoclonal antibody (SC-1225) per mouse for 5 consecutive days significantly (P < 0.01) increased the survival rate compared with that for mice treated with bovine serum albumin (BSA). Treatment with SC-1225 significantly reduced the average number of viable bacteria in portal blood, liver, and heart blood compared with the average number after treatment with BSA. Furthermore, the presence in serum of the inflammatory cytokines tumor necrosis factor alpha and interleukin 6 were evaluated as markers of severity of infection, and the results showed that the levels of these cytokines in mice treated with SC-1225 were significantly decreased in comparison with those in BSA-treated control mice. Although there was no significant difference in the number of bacteria that colonized the intestine, SC-1225 treatment significantly increased bacterial opsonophagocytosis by cultured peritoneal macrophages from mice with or without cyclophosphamide pretreatment. Our results indicate that antiflagellar human monoclonal antibody SC-1225 protects mice against gut-derived sepsis caused by P. aeruginosa and suggest that such an effect is due to its opsonophagocytic activity and the reduced motility of the translocated bacteria once the bacteria move from the intestine into the bloodstream.

Animals↗
PubMed1999

Molecular epidemiological investigation using a randomly amplified polymorphic DNA assay of Burkholderia cepacia isolates from nosocomial outbreaks.

We experienced two Burkholderia cepacia outbreaks over a 1-year period. During this period, 28 B. cepacia isolates were obtained from clinical specimens, and 2 were obtained from environmental specimens (i.e., from a nebulizer solution and a nebulizer tube). These 30 isolates were subjected to the PCR-based randomly amplified polymorphic DNA (RAPD) assay as well as to pulsed-field gel electrophoresis (PFGE). In the first outbreak, in which eight patients hospitalized in the Trauma and Critical Care Center were involved, the RAPD assay revealed that all 20 isolates obtained from clinical specimens and the 2 isolates from environmental specimens had identical DNA profiles. These RAPD data enabled us to pinpoint a possible source and to take countermeasures to prevent further spread of the epidemic-causing strain. In the second outbreak, two consecutive B. cepacia infection/colonization cases were seen in the surgery ward. The RAPD profiles of four isolates obtained were again identical, but they were distinct from those seen in the first outbreak, clearly indicating that the second outbreak was not related to the first. Thus, our experience demonstrated that the RAPD assay is a useful and reliable tool for epidemiological studies of B. cepacia isolates from nosocomial outbreaks. Since the RAPD assay could provide discriminatory potential and reproducibility comparable to those of the widely used PFGE assay with less complexity and in a shorter time, the introduction of the RAPD assay into hospital microbiology laboratories as a routine technique may help prevent nosocomial outbreaks.

Bacterial Typing Techniques↗
PubMed1999

Primary Shewanella alga septicemia in a patient on hemodialysis.

We report the first Japanese case of primary septicemia with Shewanella alga and also describe the bacteriological characteristics of and results of antibiotic susceptibility tests of the isolate. S. alga was repeatedly isolated, at times simultaneously with Escherichia coli, from the blood of a 64-year-old female undergoing hemodialysis. The isolated organism was determined to be S. alga based on recently published identification criteria, such as hemolysis on sheep blood agar, no acid production from carbohydrates, and growth on agar containing 6. 5% NaCl. Results of antibiotic susceptibility tests demonstrated that the isolate was sensitive to levofloxacin and cefpirome (MICs, </=0.063) but resistant to cefazolin, ceftizoxime, and imipenem (MICs, >128, 64, and 8 microg/ml, respectively). Although the role of S. alga as a human pathogen has not been fully determined, accumulating data suggest that this organism may be a potential pathogen, especially in compromised hosts.

Anti-Bacterial Agents↗
PubMed1998

Novel hydrogen peroxide metabolism in suspension cells of Scutellaria baicalensis Georgi.

We identified a rapid and novel system to effectively metabolize a large amount of H2O2 in the suspension cells of Scutellaria baicalensis Georgi. In response to an elicitor, the cells immediately initiate the hydrolysis of baicalein 7-O-beta-D-glucuronide by beta-glucuronidase, and the released baicalein is then quickly oxidized to 6,7-dehydrobaicalein by peroxidases. Hydrogen peroxide is effectively consumed during the peroxidase reaction. The beta-glucuronidase inhibitor, saccharic acid 1,4-lactone, significantly reduced the H2O2-metabolizing ability of the Scutellaria cells, indicating that beta-glucuronidase, which does not catalyze the H2O2 degradation, plays an important role in the H2O2 metabolism. As H2O2-metabolizing enzymes, we purified two peroxidases using ammonium sulfate precipitation followed by sequential chromatography on CM-cellulose and hydroxylapatite. Both peroxidases show high H2O2-metabolizing activity using baicalein, whereas other endogenous flavones are not substrates of the peroxidase reaction. Therefore, baicalein predominantly contributed to H2O2 metabolism. Because beta-glucuronidase, cell wall peroxidases, and baicalein pre-exist in Scutellaria cells, their constitutive presence enables the cells to rapidly induce the H2O2-metabolizing system.

Cell Wall↗
PubMed1998

Mucoepidermoid carcinoma arising in Warthin's tumour of the parotid gland: report of two cases with histopathological, ultrastructural and immunohistochemical studies.

AIMS: Malignant transformation of Warthin's tumour (WT) is a rare event. We present two cases of mucoepidermoid carcinoma (MEC) arising in WT in the parotid gland. METHODS AND RESULTS: Two cases of MEC arising in WT, which were found in 185 cases of WT of the parotid gland, were investigated by light and electron microscopy, and immunohistochemistry. Both cases had largely similar macroscopic and histological features with some differences. Histologically, the tumours consisted mainly of WT with multilayered hyperplastic arrangements of oncocytic cells and focal squamous and goblet cell metaplasia. In the same tumour mass, however, the features of MEC were observed with invasion to adjacent adipose tissue. A transitional zone between WT and MEC was evident. Both patients were alive and well without evidence of recurrence 30 and 34 months after surgery, respectively. Electron microscopy revealed that cyst lining epithelial cells in WTs had abundant mitochondria whereas some of the MEC cells contained numerous tonofilaments and mucinous granules. Immunohistochemically, oncocytic cells of WTs were strongly positive for mitochondria and SalylTn was extensively stained in MECs. The labelling index for Ki67 was obviously higher in the carcinoma cells than the epithelial cells of WT. CONCLUSIONS: Our cases confirmed the possibility of malignant transformation of the epithelial component in WT to MEC.

Adenolymphoma↗
PubMed1998

Neurotransmitters of vestibular commissural inhibition in the cat.

The present study examined transmitters that regulate commissural inhibition. Extracellular spikes of a single vestibular neuron were recorded in decerebrated cats. Multibarreled electrodes were filled with transmitter candidates (GABA and glycine), their specific antagonists (bicuculline, strychnine) and 2 M NaCl for extracellular recording. After isolation of a type I neuron, chemicals were iontophoretically applied to examine their effects on the activity of the neuron. The results were as follows. Commissural inhibition caused by electrical stimulation of the contralateral labyrinth was not abolished by the application of strychnine (a glycine antagonist), but was abolished by bicuculline (a GABA antagonist). Commissural inhibition was not abolished by phaclofen. Some bicuculline-sensitive neurons, with a short-latency commissural inhibition (presumably disynaptic inhibition), showed spacial summation when the conditioning stimulation (contralateral vestibular nerve stimulation) was applied with the test stimulation (vestibular nucleus stimulation). It was concluded that commissural inhibition was activated by the GABAA receptor, but not by the GABAB receptor, that the inhibitory type I neurons located in the contralateral vestibular nucleus were GABAergic, and that inhibitory type II neurons were also GABAergic neurons.

Animals↗
PubMed1998

Effect of immunisation with Pseudomonas aeruginosa on gut-derived sepsis in mice.

The protective efficacy of immunisation with heat-killed Pseudomonas aeruginosa on murine gut-derived sepsis was evaluated. Mice were immunised intraperitoneally six times with heat-killed bacteria. This induced mean (SEM) serum IgG and IgM antibodies of 1792 (374.7) and 37.3 (8.9) ELISA units, respectively. Specific pathogen-free mice given P. aeruginosa strain D4 orally died of bacteraemia after administration of cyclophosphamide. Immunisation with heat-killed bacteria significantly increased the survival rate compared with that of control mice immunised with bovine serum albumin. Macroscopic observation revealed marked production of liver abscesses in mice immunised with bovine serum albumin but not in those immunised with heat-killed bacteria. Only low titres of antibody against the exoenzymes alkaline protease, elastase and exotoxin A were observed, and no significant difference between antibody titres to boiled and unboiled suspensions of sonicated P. aeruginosa was detected. This suggests that the main protective antibodies might be those specific to the heat stable antigen (lipopolysaccharide). Immunisation with heat-killed bacteria provided complete protection against death from gut-derived P. aeruginosa sepsis.

ADP Ribose Transferases↗
PubMed1998

Efficacies of alkaline protease, elastase and exotoxin A toxoid vaccines against gut-derived Pseudomonas aeruginosa sepsis in mice.

The protective efficacies of vaccines prepared from Pseudomonas aeruginosa alkaline protease, elastase and exotoxin A toxoids against gut-derived P. aeruginosa sepsis in mice were evaluated. Specific pathogen-free mice given P. aeruginosa strain D4 orally followed by cyclophosphamide (to promote translocation across the gut wall) died of bacteraemia. Mice immunised with one of the three individual toxoid vaccines were not significantly protected when compared to control mice immunised with bovine serum albumin. Combined immunisation with alkaline protease and elastase toxoids likewise showed no significant protective activity. However, combined immunisation with alkaline protease and exotoxin A toxoids significantly increased the survival rate, which reached 60% (compared with a 7.1% survival rate in the control group). These results show that alkaline protease and exotoxin A play important roles as pathogenic factors in gut-derived sepsis and that a combination of the two exoenzyme toxoids represents a logical candidate for vaccination against P. aeruginosa sepsis.

ADP Ribose Transferases↗
PubMed1998

Evaluation of clinical usefulness of the microplate agglutination test for serological diagnosis of legionella pneumonia.

Recently, a microplate agglutination test (MPAT) was established for the serological diagnosis of legionella pneumonia. To evaluate its usefulness, this study examined antibody titres in 121 serum samples serially obtained from 40 patients with pneumonia, including 17 cases of confirmed legionella pneumonia. Six of the 17 proven cases became serologically positive within 4 weeks of the onset of pneumonia as assayed by MPAT (cut-off value: four-fold rise to > or = 128 in paired sera or > or = 256 in a single serum specimen), whereas the remaining 11 cases were serologically negative despite serial examination. Four proven cases who were treated with corticosteroids in the acute phase had antibody titres <8 during the first 4 weeks of infection, after which one case showed an elevation in antibody titre for the first time, 13 weeks after the onset of disease. In contrast, all non-proven cases had antibody titres of < or = 64, and only one case developed a four-fold or greater rise in titre. These results indicate that MPAT is a useful method for the laboratory diagnosis of suspected legionella pneumonia, although several false-negative cases were observed. This suggests that the previously established MPAT criteria may require modification, possibly to slightly lower values. These data also indicate that serial examination over the first month of infection may be necessary for serodiagnosis of legionella pneumonia, especially in patients treated with corticosteroids.

Agglutination Tests↗
PubMed1998

Characteristic pancreatic duct appearance in autoimmune chronic pancreatitis: a case report and review of the Japanese literature.

We report a case demonstrating the progressive narrowing of the pancreatic duct, which is presumed to be characteristic of autoimmune pancreatitis, and we review the 37 cases of chronic pancreatitis in which autoimmunity was suggested as an etiological factor in the Japanese literature. A 55-year-old man presented with abdominal discomfort, jaundice, and diffuse swelling of the pancreas on ultrasonography. Serial endoscopic retrograde pancreatography demonstrated the progression of an irregular narrowing of the main pancreatic duct forming diffusely over the course of 2 months. Because the patient had hyperglobulinemia and tested positive for autoantibodies, he was diagnosed as a case of autoimmune chronic pancreatitis. Steroid therapy was carried out with excellent success.

Autoimmune Diseases↗
PubMed1998

[Analysis of transmission of Burkholderia cepacia isolates in an intrahospital by randomly amplified polymorphic DNA-PCR method].

Strains of Burkholderia cepacia isolated in our hospital from November 1995 to September 1996 were classified with randomly amplified polymorphic DNA-PCR (RAPD-PCR) and conventional biochemical tests (ID test.NF-18, API20NE, and Neg Combo 4J kit), and intrahospital isolates of B. cepacia were analysed. During the period 28 strains from inpatients and 2 from medical apparatus were isolated. Twenty four of 28 (85.7%) were from sputum. In 1996 from January to February, 20 strains were detected from 8 inpatients, and two strains were from the nebulizers at the Trauma and Critical Care Center (TCC). With typing of B. cepacia by conventional methods no epidemiological relations among isolates were found. However, DNA patterns of original isolates from the nebulizers at TCC by RAPD-PCR were identical with those of isolates in sputa from patients in other wards who had stayed at TCC, indicating that TCC was an initial source of transmission and the strain was transmitted with the patients to the wards. These results suggest that RAPD-PCR method might be a useful tool to analyse an epidemiological survey for intrahospital transmission of isolate.

Burkholderia Infections↗
PubMed1998

Effect of interleukin-10 on gut-derived sepsis caused by Pseudomonas aeruginosa in mice.

We evaluated the protective effect of interleukin-10 (IL-10) against murine gut-derived sepsis caused by Pseudomonas aeruginosa. Gut-derived sepsis was induced by administering cyclophosphamide and ampicillin while feeding P. aeruginosa to specific-pathogen-free mice. Treating mice with recombinant human IL-10 (rhIL-10) at 1.0 or 5.0 microg/mouse twice a day following the second cyclophosphamide administration significantly increased the survival rate compared to that of control mice treated with saline; however, treatment with rhIL-10 at 0.1 microg/mouse did not result in significant protection. Bacterial counts in the liver, spleen, and blood were all significantly lower in mice treated with rhIL-10 than in saline-treated control mice. Treatment with rhIL-10 significantly suppressed tumor necrosis factor alpha, interleukin-1beta, interleukin-6, and gamma interferon levels in the serum of mice following induction of gut-derived sepsis. We also studied the effect of IL-10 on leukocyte recovery after cyclophosphamide treatment of mice. Administration of rhIL-10 intraperitoneally at 1. 0 microg/mouse significantly accelerated the recovery of leukocytes in comparison with that of the group of saline-treated controls. These results indicate that IL-10 shows a protective effect against gut-derived P. aeruginosa sepsis. We suspect that the mechanism of this effect is that IL-10 regulates in vivo production of inflammatory cytokines. Furthermore, acceleration of leukocyte recovery by IL-10 after cyclophosphamide-induced depression may also play an important role in this protection.

Animals↗
PubMed1998

In vitro and in vivo antibacterial activities of CS-834, a new oral carbapenem.

CS-834 is a prodrug of the carbapenem R-95867, developed by Sankyo Co., Ltd., Tokyo, Japan. To investigate the possibility that CS-834 may be the first carbapenem usable in an oral dosage form, its in vitro antibacterial activity (as R-95867) and in vivo antibacterial activity were compared with those of cefpodoxime proxetil, cefditoren pivoxil, cefdinir, ofloxacin, imipenem, and amoxicillin. R-95867 had high levels of activity against methicillin-susceptible staphylococci and streptococci, including penicillin-resistant Streptococcus pneumoniae, as well as Neisseria gonorrhoeae, Moraxella catarrhalis, the members of the family Enterobacteriaceae (with the exception of Serratia marcescens), Haemophilus influenzae, and Bordetella pertussis; for all these strains, the MICs at which 90% of tested strains are inhibited (MIC90s) were 1.0 microg/ml or less. Against methicillin-resistant staphylococci, enterococci, Serratia marcescens, Burkholderia cepacia, Stenotrophomonas maltophilia, and Acinetobacter calcoaceticus, R-95867 showed activity comparable to or slightly less than that of imipenem, with MIC90s ranging from 2 to >128 microg/ml. The in vivo efficacy of oral CS-834 against experimental mouse septicemia caused by gram-positive and gram-negative bacteria was better than that of comparative drugs. In murine respiratory infection models, the efficacy of CS-834 reflected not only its potent in vitro activity but also the high levels present in the lungs.

Animals↗