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Biomedical subjects

H Isogai

Publications and source records attributed to H Isogai.

At least 73 records · Page 4Linked to original sources
PubMed1991

Platelet aggregation induced by uncommon serotypes of Streptococcus sanguis isolated from patients with Behçet's disease.

Uncommon serotypes were tested for their ability to induce aggregation in platelet-rich plasma. Both uncommon and common serotypes induced platelet aggregation in rabbit platelet-rich plasma, but serotonin release was higher with the uncommon serotypes. Aggregation at ATP release varied between uncommon and common serotypes. With human platelet-rich plasma, only uncommon serotypes showed aggregation. Differences in serotype selectivity and the rate of aggregation were noted among platelet donors. About half of the patients with Behçet's disease and 30% of health controls showed platelet aggregation. Plasma from non-responder patients with Behçet's disease inhibited aggregation of healthy responder platelets within 20 min. Thus selective binding of uncommon serotypes of Strep. sanguis to platelets might cause the vasculitis in Behçet's disease.

Adenosine Triphosphate↗
PubMed1991

Colonization of Helicobacter pylori in the gastric mucosa of Mongolian gerbils.

Helicobacter pylori was orally inoculated into Mongolian gerbils. The organisms were able to colonize in the gastro-mucosal layer of the gerbils, especially in those gerbils which had mucosal lesions caused by indomethacin treatment. The pathological changes developed by H. pylori infection were restricted to the stomachs, and only slightly inflammatory cells were observed.

Animals↗
PubMed1991

Serological survey for Lyme disease in sika deer (Cervus nippon yesoensis) by enzyme-linked immunosorbent assay (ELISA).

Seventy-six wild sika deer (Cervus nippon yesoensis) from areas endemic for Borrelia burgdorferi during 1988 to 1989 had the IgG antibody to the bacteria in enzyme-linked immunosorbent assay. The percentage of seropositive deer was 25.0% to strain HO14 and 22.4% to strain HP3, respectively. Specific IgG antibody titers were high in summer but low in winter. In summer, seropositive deer were 75.0%. Similar results were obtained in serum specimens obtained monthly from 4 farmed deer. It was suggested that the sika deer could be one of the wild reservoirs for B. burgdorferi in Hokkaido, Japan. The transmission risk of B. burgdorferi is considered to be greatest during late spring to early summer.

Animals↗
PubMed1990

Chemiluminescence of neutrophils from patients with Behçet's disease and its correlation with an increased proportion of uncommon serotypes of Streptococcus sanguis in the oral flora.

Zymosan-induced chemiluminescence was investigated in whole blood and in neutrophils: in both, the peak count was frequently elevated in Behçet's disease, and was significantly higher than in healthy controls; similarly the peak time was shorter. There were more uncommon serotypes of Streptococcus sanguis in the oral flora of patients with Behçet's disease. Common serotypes were present in the flora of healthy controls, but not in patients with the disease. The percentage of Strep. sanguis in the oral flora was significantly correlated with the level of chemiluminescence response. Thus infection with uncommon serotypes of Strep. sanguis may play a role in the aetiology of Behçet's disease.

Behcet Syndrome↗
PubMed1990

Macrophage activation by leptospiral lipopolysaccharide.

Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovars copenhageni and hebdomadis were tested for the ability to induce macrophage activation. In-vitro analysis showed that each leptospiral LPS was a potent activator to macrophages. After stimulation with the LPSs, interleukin-1 (IL-1) secretion, interferon (IFN) production and chemiluminescence (CL) response were induced. Intravenous high-dose injection of the leptospiral LPSs induced various lesions such as necrosis of the liver, and the LPSs were detected in macrophages in the liver, spleen and lymphnodes by immunohistochemical examination. Enhancement of macrophage activity in mice inoculated with low doses of leptospiral LPS was recognized. The macrophages of the LPS-treated mice showed a significantly higher bactericidal action than those of control mice. The beta-galactosidase and nitroblue tetrazolium (NBT) positive cells in macrophages of the LPS-treated mice increased significantly. In the NBT reduction test after phagocytosis of latex beads or Salmonella typhimurium, the macrophages of the LPS-treated mice showed a significantly higher activity than those of control mice.

Animals↗
PubMed1990

Antibodies to Borrelia burgdorferi in dogs in Hokkaido.

During 1985 to 1990, serum samples were obtained from 229 healthy dogs. The dogs lived in Hokkaido, known to be infested with ticks. An enzyme-linked immunosorbent assay (ELISA) was used to detect IgG and IgM antibodies against Borrelia burgdorferi HO14 and HP3, which were isolated from Ixodes ovatus and I. persulcatus in the area. IgG antibody to B. burgdorferi HO14 was detected in 8.8% (1985), 16.4% (1987) and 18.5% (1990). IgM antibody to the bacteria was detected in 1.8% (1987) and 2.5% (1990). Antibodies to the strain HP3 of B. burgdorferi were also detected in the serum samples of dogs, but the percentage of seropositive sample to the strain HP3 was lower than that to the strain HO14. Statistical differences were not noticed between pet and street dogs. No antibody to B. burgdorferi was observed in 13 beagle dogs as experimental animal.

Age Factors↗
PubMed1990

[Comparison of three methods for detecting Campylobacter pylori and measurement of human antibody titers against the whole organisms].

In order to detect Campylobacter pylori in the gastric mucosa, three different methods as 1) culture of the organisms, 2) immunostaining by monoclonal antibody against the cells, and 3) urease test were compared. In the disease group, positive % of each methods was 64, 75 and 74. However, positive % common to the three methods was only 48. The corresponding rate of culture and urease tests, and that of culture and staining methods was 81% and 60%, respectively. Therefore, it was concluded that urease test was a useful method, and that the three methods were necessary to confirm the existence of the organisms in the gastric mucosa. Total positive % of culture and staining methods in disease and control groups was 77 and 31, respectively, indicating that positive % of the disease group was much higher than that of the control group. Anti C. pylori titer was compared between culture-positive and culture-negative patients by ELISA. The titer of the former was significantly higher than that of the latter.

Antibodies, Bacterial↗
PubMed1990

Biological effects of leptospiral lipopolysaccharide to mouse B, T and NK cells.

Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovars copenhageni and hebdomadis were tested for the biological effect to mouse B, T and NK cells. Each leptospiral LPS was a potent mitogen for spleen B cells. Activation of the cells was also expressed by polyclonal B cell activation. In contrast, mitogenicity for T cells, induction of interleukin-2 (IL-2) secretion in T cells and increase of tumor-killing activity and chemiluminescence in NK cells were not observed after stimulation with leptospiral LPS. After intravenous injection of leptospiral LPS in mice, the spleen and lymphnodes were examined by histocytochemical technique. Increase of Ig-bearing lymphocytes was recognized while decrease of T cells was observed in the lymphoid organs. Mitogenic response to PHA, Con A and PWM decreased with relation to the T cell depletion. In conclusion, it is apparent that leptospiral LPS possess marked immunological potencies on B cells but not T and NK cells. The biological effects of leptospiral LPS were common ones as LPS but the level was considered to be different from classical LPS such as Escherichia coli LPS.

Animals↗
PubMed1989

Effects of leptospiral lipopolysaccharide on rabbit platelets.

Leptospiral lipopolysaccharides (LPSs) extracted from Leptospira interrogans serovar copenhageni virulent strain Shibaura, serovar canicola virulent strain Moulton, and serovar hebdomadis strain Hebdomadis, were tested for their ability to induce platelet aggregation and/or lysis in rabbit platelet-rich plasma (PRP). All showed positive reactions with a release of adenosine triphosphate (ATP) and serotonin. The values, however, were different from each other. The ability of leptospiral LPS extracted from serovar copenhageni virulent strain Shibaura (I-LPS) to induce platelet aggregation was the highest of all. After treatment of I-LPS, the platelets developed a ruffled surface with appearance of pseudopodia as observed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). I-LPS also showed cytotoxicity for the platelets. Degenerative or lytic changes were recognized in 44.5% of the platelets which were observed 60 min after I-LPS treatment.

Adenosine Triphosphate↗
PubMed1989

Chemiluminescence and phagocytic responses of rat polymorphonuclear neutrophils to leptospires.

The interaction of leptospires with polymorphonuclear neutrophils (PMN) was examined by the luminol-dependent chemiluminescence (CL) test. Whole blood CL changed in relation to the stage of leptospiral infection both in susceptible (SUS) and resistant (RES) rats. The intensity of CL grew with an increasing number of leptospires in the blood. CL responses were observed in isolated PMN upon exposure to living leptospires. In contrast, the same bacteria, having been inactivated by formalin, did not stimulate PMN. A variation was found in the CL response by different living strains of Leptospira. The CL intensity was arranged as follows: L. illini greater than L. biflexa greater than L. interrogans avirulent strains greater than L. interrogans virulent strains. The CL response was markedly enhanced by an opsonization of leptospires. Specific opsonization was shown to increase the rate of phagocytosis of leptospires with relation to the CL response.

Animals↗
PubMed1989

Biological effects of lipopolysaccharide from Achromobacter stenohalis on lymphocytes and macrophages.

The immunopotentiating activities of lipopolysaccharide from Achromobacter stenohalis (A-LPS) were examined. A-LPS was structurally atypical and gave no endotoxin shock in A-LPS-inoculated mice. Analysis in vitro showed that A-LPS was a potent activator of both macrophages and B-lymphocytes. After macrophage stimulation with A-LPS, interleukin-1 (IL-1) secretion, interferon (IFN) production and chemiluminescence (CL) response were induced. A-LPS was a potent mitogen for spleen lymphocytes. However, induction of interleukin-2 (IL-2) secretion in T lymphocytes was not observed. These activities of A-LPS were similar to or higher than that of enterobacterial LPS.

Alcaligenes↗
PubMed1989

Oral flora of mongrel and beagle dogs with periodontal disease.

The plaque flora was studied in adult mongrel and beagle dogs with periodontal disease. Gingival plaque from maxillary premolars was removed and cultured on various growth media. The flora in all dogs was composed of mostly anaerobic gram negative rods. Bacteroides asaccharolyticus was found in the highest proportion of plaque samples from mongrel dogs, and decomposed hydrogen peroxide suggesting catalase activity. Fusobacterium nucleatum was found in higher proportion in the plaque of beagle dogs as compared to B. asaccharolyticus. With the increasing numbers of obligative anaerobic gram negative organisms such as B. asaccharolyticus, the proportions of Streptococcus, Enterococcus and Staphylococcus decreased in the dogs with periodontal disease. The salivary flora was different from the plaque flora of the dogs with periodontal disease. It was constant regardless with the disease. The salivary flora of beagle dogs with the healthy gingiva was different from that of mongrel dogs. Enterococcus, Lactobacillus, Eubacterium and black-pigmented Bacteroides (BPB, mainly B. asaccharolyticus) were higher proportion in the flora of beagle dogs as compared to mongrel dogs, while Fusobacterium, Enterobacteriaceae, yeast and molds were lower in the flora. The results reveal that B. asaccharolyticus and F. nucleatum are common pathogens and uniquely contribute to the development of gingival inflammation in dog.

Animals↗
PubMed1989

Epidemiological study on periodontal diseases and some other dental disorders in dogs.

The prevalence of dental disorders in dogs was studied by applying index systems for human with some modifications. A total of 251 mongrel dogs including 143 stray dogs kept in the Animal Protection Offices in Tokyo and Hokkaido and 108 pet dogs visiting veterinary clinicians in Chiba Prefecture and Hokkaido were used. Periodontitis was prevalent among these dogs regardless of their sources and its incidence was increased with age. The lesion was more severe and more frequent in the premolar and molar regions than in the maxillary and mandibular incisor regions. Missing of teeth was observed at a high and increasing incidence with age. The tooth most commonly lost was the first premolar, followed by the other premolars and molars, where severe periodontitis was frequently found. Calculus was seen on many teeth, and aging agravated its prevalence and severity. Dental caries was observed in stray dogs, but neither to a serious degree nor at a significant level. These findings emphasize the necessity of dental hygiene, proper dental care and continuous periodical survey for dogs.

Age Factors↗
PubMed1989

Escherichia coli associated endotoxemia in dogs with parvovirus infection.

Escherichia coli bacteremia and endotoxemia were observed in 3 adult mongrel dogs which had been prediagnosed as canine parvoviral disease. The endotoxin level was 46.5 pg/ml in the plasma of clinical cases, while 2.3 pg/ml in healthy controls. The microflora of the feces was confused in the clinical cases. The percentage of E. coli was major in the feces. Serologically similar strains were isolated from the blood. These strains did not produce enterotoxins such as heat-stable enterotoxin (ST) and heat-labile enterotoxin (LT). Histopathologically, the lesions in the small intestine consisted of epithelial degeneration and necrosis. Viral inclusion bodies were frequently observed in the epithelial cells. Disseminated intravascular coagulation was observed in various tissues including the liver and small intestinal submucosa. After experimental infection with CPV, all dogs showed various clinical signs. CPV was positive in the feces. Endotoxin level in the plasma gradually increased and high level continued for long period from 10 to 30 days. Mean maximum level of endotoxin in the experimental dogs was 73.6 pg/ml. These results indicate that intestinal flora plays a important role in the pathogenesis of CPV infection and that endotoxin is one of the factors which predispose to severe disease after the infection.

Animals↗
PubMed1988

Specific inhibition of adherence of an oral strain of Bacteroides gingivalis 381 to epithelial cells by monoclonal antibodies against the bacterial fimbriae.

Monoclonal antibodies against purified fimbriae from this organism blocked its adherence to buccal epithelial cells. Three clones of monoclonal antibodies against these fimbriae were selected for use. The isotype of the three was IgG1 kappa chain. The antibodies reacted with fimbriae or their partially dissociated oligomers, but not with their constituent monomers (43 K protein, fimbrilin) or with other B. gingivalis 381 components, in an enzyme-linked immunosorbent assay or by immuno-blotting. The antibodies agglutinated only B. gingivalis 381 cells and no other species of Bacteroides. The purified immunoglobulin G (IgG) antibodies inhibited bacterial adherence to the human buccal epithelial cells, but had no effect on bacterial haemagglutination to various animal and human erythrocytes. The papain-cleaved Fab fragment, which did not allow cell to cell cross-linking, also inhibited adherence of B. gingivalis 381 but did not interfere with haemagglutination. Thus the fimbriae of B. gingivalis 381 may be responsible for adherence to epithelial cells, which supports the notion that a different type of fimbria or a lectin-like protein may be acting as haemagglutinin in this bacterium.

Antibodies, Monoclonal↗