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H Isogai

Publications and source records attributed to H Isogai.

At least 37 records · Page 2Linked to original sources
PubMed1997

Role of platelet-activating-factor (PAF) on cellular responses after stimulation with leptospire lipopolysaccharide.

Leptospire lipopolysaccharide (LPS) stimulated the adherence of polymorphonuclear neutrophils (PMNs) to human umbilical vein endothelial cells (HUVEC). Enhanced PMN adherence in response to leptospire LPS can be mediated by platelet-activator-factor (PAF), because a PAF antagonist reduced adherence. Leptospire LPS also induced the adherence platelets or U937. The second experiment involved leptospire LPS elicited platelet aggregation in a PMN-platelet mixture, because leptospire LPS stimulated human PMN but not the human platelets. The platelet response was observed only in the mixture system and was inhibited by a PAF antagonist. PAF could be an important pathogenic factor in human leptospirosis.

Animals↗
PubMed1997

Experimental Helicobacter pylori infection in association with other bacteria.

We performed surgical treatment on normal ddY mice before Helicobacter pylori inoculation. The treatment was expected to obstruct bacterial flow out of the stomach and increase the chance of bacterial attachment to the gastric epithelium in mice. The bacterial challenge induced inflammation in the stomach. H. pylori was recovered from the stomach throughout the observation period. Lactobacilli and streptococci tended to relate to the increase in number of H. pylori recovered. Pretreatment with atropine was considered to confuse the gastric flora and affect the number of H. pylori recovered. These results suggested that a certain amount of time is necessary for H. pylori to contact with the gastric epithelium and that the composition of flora is important for the establishment of H. pylori infection.

Adjuvants, Anesthesia↗
PubMed1997

Levels of endogenous interleukin-1, interleukin-6, and tumor necrosis factor in congenic mice infected with Borrelia garinii.

This study describes the levels of interleukin-1 alpha (IL-1 alpha), tumor necrosis factor alpha (TNF alpha) and interleukin-6 (IL-6) in the sera and parenchymal organs of various congenic mouse strains infected with Borrelia garinii. A significant elevation of inflammatory cytokine levels was found in the organs of C3H/HeN (H-2k) and B10.BR (H-2k) mice but not in those of BALB/c mice (H-2d). Focally produced cytokines can contribute to antimicrobial defense against these organisms. High levels of IL-1 alpha were observed in the sera of C3H/HeN, B10.BR and B10 (H-2b) mice infected with B. garinii and they were associated with the presence of spirochetes in the skin. Thus, susceptible mice demonstrated a stronger cytokine response than resistant mice. This study presents in vivo evidence that B. garinii infection affects the immunopathogenesis of Lyme disease.

Animals↗
PubMed1996

Mosaic type of the nontoxic-nonhemaggulutinin component gene in Clostridium botulinum type A strain isolated from infant botulism in Japan.

The gene encoding the nontoxic-nonhemaggulutinin (NTNH) component was amplified by the PCR technique using two primer sets and the DNA template from Clostridium botulinum type A strain 7I03-H isolated from infant botulism in Japan. The nucleotide sequence revealed that the NTNH gene was composed of 1,193 amino acids with a molecular weight of 130868.08. Furthermore, the N-terminal half side and C-terminal half side of the NTNH component were similar to the NTNH component of type C and type A, respectively. These results indicate that the NTNH component gene codes the mosaic NTNH component composed of type A and type C. The hemaggulutinin gene, aha, and ORF-22 gene, orf-22a, were undetectable in the region upstream of the NTNH component gene, ant. Therefore, orf-22a is not thought to play a key role in the expression of botulinum type A progenitor toxin gene.

Amino Acid Sequence↗
PubMed1996

Characterization of component-I gene of botulinum C2 toxin and PCR detection of its gene in clostridial species.

Botulinum C2 toxin is composed of two nonlinked protein components, component-I (light chain) and component-II (heavy chain). It is produced by Clostridium botulinum types C and D, and is thought to play a lethal pathogenic role. These biological activities of C2 toxin may be due to the ADP-ribosylation of non-muscle actin by component-I of the toxin. We were able to isolate two overlapping gene fragments encoding component-I from the chromosomal DNA of Clostridium botulinum type C strain (C)-203U28, and determine the complete nucleotide sequence of component-I gene. The gene for component-I, bc21, consists of one open reading frame (ORF) encoding 431 amino acid residues (1293 nucleotides) without signaling peptide sequence. The molecular mass calculated from the deduced amino acid sequence was 49400.37 Da. Mono-ADP-ribosyltransferase activity was demonstrated in the lysate from E. coli transformed by the recombinant plasmid, pGEM-C2 encompassing whole component-I gene with its own promoter.

Amino Acid Sequence↗
PubMed1996

Quantitative detection of secretory immunoglobulin A to Helicobacter pylori in gastric juice: antibody capture enzyme-linked immunosorbent assay.

Helicobacter pylori is a major etiologic agent in gastroduodenal disorders. In this study, immunoglobulin A (IgA) antibodies to H. pylori were estimated in serum and gastric juice specimens from patients with gastritis and peptic ulcers using antibody capture enzyme-linked immunosorbent assays (ACELISAs). The antibody titers of the ACELISAs are independent of the antibody concentration and reflect the ratio of H. pylori-specific IgA to total IgA. The ratio is stable, although the antibody concentration fluctuates in gastric juice. Using the ACELISAs it was possible to evaluate quantitatively not only serum IgA (SR-IgA) antibodies but also secretory IgA (SC-IgA) antibodies in gastric juice. There were significant differences between the patients and control group in the SR-IgA and SC-IgA ACELISAs. Furthermore, the ACELISAs made it possible to compare between SR-IgA antibodies in serum and SC-IgA antibodies in gastric juice. In all patients, the ratios of H. pylori-specific IgA were higher in gastric juice than in serum. These results suggest that H. pylori SC-IgA antibodies are mainly produced by the local immune response in the gastric mucosa. Our studies indicate that ACELISA is well suited for the analysis of local immune response in mucosa.

Adult↗
PubMed1996

Cytokines in the serum and brain in mice infected with distinct species of Lyme disease Borrelia.

This study describes the detection of cytokines, interleukin-1 alpha (IL-1 alpha), tumor necrosis-factor alpha (TNF alpha) and interleukin-6 (IL-6) in the serum and brain homogenates of susceptible and resistant strains of mice infected with distinct species/strains of Borrelia. Significant elevation of inflammatory cytokines was found in the sera of susceptible C3H/ HeN mice but not in the sera of resistant BALB/c mice on days 7 and 45 after inoculation. Brain cytokines were observed in C3H/HeN mice infected with B. garinii and B. afzelii and the production was associated with the presence of spirochetes. B. japonica was the only exception in disease-susceptibility and cytokine production of mice. These results suggest that there are differences in pathogenic potential amongst Borrelia strains, and that the susceptible mice demonstrate a stronger cytokine response and greater frequency of recovery of Borrelia from the brain than do the resistant mice.

Animals↗
PubMed1996

Detection of antibodies to Borrelia species among patients with confirmed sarcoidosis in a region where Lyme disease is nonendemic.

BACKGROUND: Lyme disease is a multisystemic disorder caused by the spirochete Borrelia burgdorferi, while sarcoidosis is a multisystemic granulomatous disease of unknown etiology. The purpose of this study was to evaluate the relationship between Lyme disease and sarcoidosis. METHODS: We examined the seroprevalence of antibody to Borellia species in patients with sarcoidosis. We performed the enzyme-linked immunosorbent assay, using three Japanese Borrelia species in addition to B. burgdorferi, and dotblot analysis using purified Borrelia-specific proteins in 38 patients with histopathologically confirmed sarcoidosis and 80 healthy controls. RESULTS: Two patients (5.3%) were positive for antibodies to Borrelia species according to one or both assays, and one (1.2%) healthy control was positive. In both patients it was suspected that Borrelia infection had developed prior to the development of sarcoidosis. CONCLUSION: Borrelia species were thought not to be responsible for the development of sarcoidosis in a nonendemic region in Japan. Since clinical manifestations of Lyme disease share certain similarities with those seen in sarcoidosis, ophthalmologists should be aware of the need to differentiate between the two diseases and the need for prompt treatment in each case.

Adult↗
PubMed1996

Comparison of OspA serotypes for Borrelia burgdorferi sensu lato from Japan, Europe and North America.

UNLABELLED: Sixty-one Borrelia burgdorferi sensu lato strains from various sources (ticks, human, and wild animals) in Japan and two strains from ticks in Far Eastern Russia were classified on the basis of reactivity with 16 monoclonal antibodies (mAb) to outer surface protein A (OspA) and by DNA-DNA hybridization assay. Eleven OspA serotypes (J1 to J11) were recognized among the Japanese and the Far East Russian isolates (serotypes J1 to J9 were identified as B. garinii, serotype J10 was identified as B. afzelii, and serotype J11 corresponded to B. japonica), whereas 7 OspA serotypes for North American and European isolates previously reported (Bettina Wilske et al, J. Clin. Microbiol. 31:340-350,1993) were not observed except for OspA serotype 2 which showed identical reactivity with OspA serotype J10. This finding provides helpful information for understanding the geographical distribution of Lyme disease borrelia and the development of vaccine and diagnostic tests. IN CONCLUSION: 1.B. burgdorferi sensu stricto has not been observed in Japan, 2. Japanese B. afzelii isolates are closely related to those from Europe, 3. B. garinii isolates from Japan are highly heterogeneous and apparently different from European B. garinii isolates.

Animals↗
PubMed1996

Borrelia burgdorferi sensu lato in an endemic environment: wild sika deer (Cervus nippon yesoensis) with infected ticks and antibodies.

Ticks and blood samples were collected from wild sika deer (Cervus nippon yesoensis) during a hunting season (August to October) of 1991 at a selected location in Hokkaido, Japan. Ixodes persulcatus (adult and nymph) and I. ovatus (adult) were the common ticks on sika deer. Spirochetes were detected in the midgut of the ticks by the indirect peroxidase-conjugated antibody staining method and by dark-field microscopy after cultivation. By the reactive pattern of monoclonal antibodies, isolates were considered to belong to Borrelia garinii or B. japonica. In an antibody test, the percentage of seropositive deer was 69.0%. Most of the adult sika deer were positive for antibodies to the spirochetes. There are significant age-dependency in antibody level and seropositive rate. The surveillance of deer should be valuable in monitoring the transmission risk of B. burgdorferi sensu lato in nature.

Age Factors↗
PubMed1996

Immunological studies on venereal spirochetosis of rabbits (rabbit syphilis).

White rabbits in a family, which were clinically diagnosed as moderately or severely diseased with spirochetosis, were bacteriologically and immunologically examined. The specimens from the diseased rabbits, including affected prepuces, scrotum, or skins with an occasional presence of the spirochetes, did not, however, result in growth in six conventional culture media. Serological tests, including quantitative complement fixation test, rapid plasma reagin card test, Treponema pallidum hemagglutination test, and microscopic agglutination test for leptospires using sera from diseased rabbits showed no differences when compared with those of pooled normal rabbit sera. Immunoblot analysis of the polypeptides from three human oral treponemes and three non-oral spirochetes demonstrated that antibodies against several treponemal polypeptides were detected.

Animals↗
PubMed1996

Platelet-activating-factor-mediated pathogenesis in Lyme disease.

This study describes a role of platelet-activating factor (PAF) as a potential inducer of inflammation in infection with Borrelia burgdorferi. Two approaches were taken. The first involved the use of a PAF antagonist to show the lack of an inflammatory response in skin lesions. The second was to show that the PAF antagonist reduced platelet aggregation when the spirochetes were incubated with polymorphonuclear leukocytes.

Animals↗
PubMed1995

T cell response to Borrelia garinii, Borrelia afzelii, and Borrelia japonica in various congenic mouse strains.

The infectivity and T cell response to Borrelia garinii SIKA2, Borrelia afzelii BFOX, and Borrelia japonica 0612, the organisms that cause Lyme disease in Japan, were examined in various inbred and congenic strains of mice. Infectivity differed among the species: B. garinii SIKA2 and B. afzelii BFOX were each able to infect 90% to 100% of C3H/He mice; B. japonica 0612 was able to infect only 20% of C3H/He mice. The pattern of infectivity to various inbred and congenic strains of mice may influence the pathogenicity of the organism and the clinical signs of Lyme disease. Cross-reactivity between Borrelia antigens was observed, but there was no cross-reactivity between Borrelia antigens and Leptospira antigens. We evaluated the genetic control of the delayed-type hypersensitivity (DTH) reaction in the form of footpad swelling produced by Borrelia antigens using viable or sonicated bacteria as sensitization. Differences in strains of mice infected by viable antigen were observed. However, all strains of mice showed a strong DTH reaction using sonicated antigens without genetic background. A DTH reaction in the form of footpad swelling did not appear to be associated with genetic background. The footpad reaction was mediated by CD4+8- and Ia- T cells, as revealed by in vitro monoclonal antibody treatment. However, CD8+ T cells did not suppress footpad swelling. These results indicate that many antigenic epitopes of the Borrelia spirochete can stimulate the DTH reaction.

Animals↗
PubMed1995

Prevalence of antibodies against Borrelia species in patients with unclassified uveitis in regions in which Lyme disease is endemic and nonendemic.

We studied 93 patients with unclassified uveitis from two regions in Japan (Hokkaido and Kanagawa) to assess the contribution of Borrelia species to this condition. The seroprevalence of antibody to Borrelia species was higher in patients from Hokkaido than in those from Kanagawa. The unclassified uveitis of seropositive patients was probably a complication of Lyme borreliosis since (i) the antibody titers were as high as those in clinically diagnosed Lyme disease patients, (ii) healthy controls from Hokkaido showed low seroprevalence in contrast with unclassified uveitis patients from Hokkaido, and (iii) the reaction pattern of antibodies in sera from patients with unclassified uveitis was the same as that in patients with Lyme disease. This is the first report to reveal the high risk of Lyme borreliosis in patients with unclassified uveitis in regions endemic for Lyme disease. In case of unclassified uveitis as well as in cases of inflammatory disease of unknown origin, Lyme disease should be taken into consideration, especially in regions in which Lyme diseases is endemic, even if it is reported only in animals.

Animals↗
PubMed1994

Canine Lyme disease: clinical and serological evaluations in 21 dogs in Japan.

Of 21 dogs from Sapporo, Hokkaido that had been recognised as having been bitten by ticks, 16 were seropositive to Borrelia burgdorferi by ELISA. Thirteen of the seropositive dogs showed signs such as fever, astasia, convulsions, anorexia, fatigue, abnormal gait, nervous signs, diarrhoea, corneal opacity and conjunctivitis. These signs subsided as a result of antibiotic treatment within five days. The plasma concentrations of creatinine in the 21 dogs were higher than in control dogs. Seven ticks that were removed from seven of the dogs were Ixodes persulcatus, and B burgdorferi was isolated from the midgut of two of the ticks.

Animals↗
PubMed1994

Helicobacter pylori induces inflammation in mouse urinary bladder and pelvis.

Helicobacter pylori was transurethrally inoculated into the mouse urinary tract. The organism established infection and induced inflammation in the urinary bladder and pelvis. During the infection, urinary pH was elevated, probably due to the production of NH3 by bacterial urease. H. pylori was recovered from the urinary bladder, kidney and urine of the infected mice. Histopathologically, severe neutrophil infiltration was observed in the mucosal layer of both organs. H. pylori was detected on the surface of the epithelial cells. These results indicate that low pH and bacterial flora were not essential factors in establishing the mucosal infection with H. pylori. This experimental system is useful to investigate the pathogenicity of H. pylori in mucosal organs.

Animals↗