Biomedical subjects

E Isogai

Publications and source records attributed to E Isogai.

At least 91 records · Page 5Linked to original sources

PubMed1995

Changes in the nucleosomal structure of the Marek's disease virus genome in lymphoblastoid cell line MDCC-MSB1 induced by 5-azacytidine.

Marek's disease virus (MDV) DNA in latently infected lymphoblastoid cell lines is considerably methylated. Treatment of the MDV-derived lymphoblastoid cell lines MDCC-MSB1 (MSB1) and MDCC-RP1 (RP1) with 5-azacytidine (5-AzC) results in hypomethylation of MDV DNA. An increase in mRNA from certain portions of MDV DNA, including the BamHI-H region, was observed in 5-AzC-treated MSB1 cells, but not in the agent-treated RP1 cells. After the treatment of cells with 5-AzC, a site hypersensitive to digestion with DNaseI appeared in the BamHI-H region of MDV DNA in MSB1 but not in RP1. These results suggested that the enhancement of mRNA synthesis by 5-AzC is associated with changes in the nucleosomal structure of MDV DNA in lymphoblastoid cell line MSB1.

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

Involvement of antipain-sensitive protease activity in suppression of UV-mutagenicity by human interferon-alpha.

To study the relationship between the transient elevation of protease activity and hypomutability observed in hypermutable human RSa cells pretreated with human interferon (HuIFN)-alpha and then irradiated with far-ultraviolet light (UV), protease inhibitors capable of specifically inhibiting the activity were investigated. Of ten inhibitors tested, antipain showed the greatest inhibitory effect. Antipain also prevented the suppression of UV-mutagenicity by HuIFN-alpha in RSa and xeroderma pigmentosum-derived fibroblast cells, as shown by culturing cells in medium containing antipain immediately after UV exposure and evaluating the generation of clones resistant to ouabain- or 6-thioguanine-mediated cytotoxicity. Thus, an antipain-sensitive protease may be involved in the hypomutability induced by HuIFN-alpha.

Antipain↗

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↗

PubMed1994

Complement-mediated killing of Borrelia garinii--bactericidal activity of wild deer serum.

The susceptibility of Borrelia garinii to fresh wild deer sera was determined by incubating strain SIKA2 at 10% serum concentration for 1 hr at 37 C in an in vitro bactericidal assay. Each serum showed bactericidal effects at various levels. The effect was dependent on the concentration of antibody to the spirochetes. Complement was essential in the bactericidal assay because the inactivated deer serum showed greatly decreased activity. Our results suggest that B. garinii is sensitive to deer serum, in the presence of antibody and the bactericidal effect is important for preventing Lyme disease in wild sika deer.

Animals↗

PubMed1994

Fimbria-specific immune response in various inbred mice inoculated with Porphyromonas gingivalis 381.

We studied the genetic control of Porphyromonas gingivalis fimbriae response. Inbred mice with different H-2 haplotypes and/or different genetic backgrounds were inoculated with viable P. gingivalis 381 cells and tested for fimbria-specific T cell responses in vivo (delayed-type hypersensitivity). H-2d mice showed a strong footpad response, whereas H-2b mice showed a weak response to fimbriae from P. gingivalis. Similar evidence of genetic control was obtained with an enzyme-linked immunosorbent assay for the detection of IgG antibody in inbred mice (BALB/c, C3H/HeN and C57BL/6). Several immunoglobulin G (IgG) subclass responses were associated with H-2 in these B10 congenic mice. However, quantification of IgG antibody to fimbriae was not controlled by H-2 in B10 congenic mice. The results indicate that, in mice, the responsiveness to fimbriae of P. gingivalis can be controlled by several genes, including the H-2 complex. C3H/HeN mice were inoculated with the fimbriae intravenously, and the expression of surface antigens on spleen T cells was measured in a fluorescent antibody cell sorter. Stimulation by fimbriae resulted in a changed expression of surface antigens on T cells. Thus, the fimbriae can induce T cell activation.

Animals↗

PubMed1994

Experimental Borrelia garinii infection of Japanese quail.

Japanese quail inoculated subcutaneously with Borrelia garinii responded to infection. B. garinii was reisolated mainly from skin and randomly from several organs between 7 and 56 days postinoculation. Skin lesions were occasionally observed in association with spirochete recovery. All birds were positive for antibody at 53 to 56 days postinoculation. These results suggest that the Japanese quail is a model for experimental infection with B. garinii and that birds are reservoirs for Lyme disease spirochetes.

Animals↗

PubMed1994

Enhancement of mRNA synthesis from Marek's disease virus genome in the lymphoblastoid cell line, MDCC-MSB1, by 5-azacytidine.

Marek's disease virus (MDV) DNA in latently infected lymphoblastoid cell lines is considerably methylated. A treatment of the MDV-derived lymphoblastoid cell line, MDCC-MSB1 (MSB1), with 5-azacytidine (5-AzC) resulted in a hypomethylation of MDV DNA and an increase in mRNA from certain portions of the MDV DNA. These results suggest methylation of MDV DNA as being one of the factors associated with a repression of transcription of MDV DNA in the lymphoblastoid cell line, MSB1.

Animals↗

PubMed1994

Subgingival temperature in rats with natural gingivitis.

Elevated temperature, normally a characteristic of inflammation, is a potential indicator of periodontal disease. The present investigation examined the relationship of subgingival temperature and various indicators of gingivitis in rats with spontaneous gingivitis (SUS rat) and in control rats (RES rat). In 24 SUS rats with gingivitis, the subgingival temperature rose, but not in 6 SUS and 20 RES rats with healthy gingiva. Subjects with high mean subgingival temperatures had significantly higher mean percentages of Prevotella intermedia and Fusobacterium nucleatum than age-matched RES rats. The results show that dental plaque, including specific bacteria P. intermedia and F. nucleatum, can play some role in causing the elevated temperatures.

Age Factors↗

PubMed1994

Lyme disease spirochetes in a wild fox (Vulpes vulpes schrencki) and in ticks.

Lyme disease spirochetes were demonstrated in a wild female fox (Vulpes vulpes schrencki) and in Ixodes persulcatus ticks collected from the fox on Sapporo, Hokkaido, Japan. Spirochetes were detected in I. persulcatus, as well as skin lesions, brain, heart, kidney, and liver of the fox. Five of seven isolates reacted with a monoclonal antibody against Borrelia afzelii specific Osp B. Deoxyribonucleic acid (DNA) relatedness of a brain isolate was 89% to B. afzelii, and ranged from 50 to 67% to three other species. Immunoglobulin G antibodies to B. afzelii, B. garinii and B. burgdorferi sensulato, when tested in an enzyme-linked immunosorbent assay (ELISA), were negative in the fox. There were no antibodies against seven serovars of Leptospira interrogans.

Animals↗

PubMed1993

Neutrophil dysfunction in rats with natural gingivitis.

The functions of polymorphonuclear neutrophils (PMN) from SUS rats with naturally occurring gingivitis were examined by the luminol-dependent chemiluminescence (CL), adherence and bactericidal tests. SUS rats with pre-gingivitis showed lower CL responses of isolated PMNs and whole blood than control rats (RES rats). After plague formation and progression of gingivitis, the CL response gradually increased in SUS rats. RES rats had healthy gingiva and showed no increase in CL responses. Impaired PMN adherence was observed in SUS rats with pre-gingivitis but not in RES rats. PMNs from SUS rats with pre-gingivitis also showed lower bactericidal activity than those from RES rats. Dysfunction of PMNs might induce gingivitis as a result of decreased protection against periodontal pathogens and an elevated level of CL response can be recognized with progression of gingivitis.

Animals↗

PubMed1993

Demonstration of antigen-specific immune response against Streptococcus sanguis.

The genetic control of Streptococcus sanguis antigen response was studied. Mice sensitized with inactivated S. sanguis organisms antigen-injected at the base of the tail developed footpad swelling. Those with an I-Ak,q,r region of H-2 showed a strong footpad response, whereas those with an I-Ab,d,s region showed a weak response to S. sanguis cell wall antigen. Footpad response was mediated by CD4+,8- T cells by using in vitro monoclonal antibody treatment. Similar evidence of genetic control was obtained with an in vitro T cell proliferation assay. However, quantitation of antibodies against S. sanguis showed that antibody production was not controlled by H-2. These results indicated that both in vivo footpad swelling and in vitro T cell proliferation responses were functions of helper (CD3+,4+,8-) T cells and controlled by the I-A region of H-2.

Animals↗

PubMed1993

Neurologic abnormalities in two dogs suspected Lyme disease.

A 2-year-old mongrel dog developed neurological signs following tick bite. These included astasia, persistent tonic convulsions and hyper-reflexia. Both serum IgG and IgM antibody titers against Borrelia burgdorferi were positive in enzyme-linked immunosorbent assay (ELISA). The neurological signs subsided after high-dose penicillin and streptomycin treatment. A strain of spirochetes (P427a) was isolated from the midgut of Ixodes persulcatus feeding on the dog. Morphological characteristic, immunological property and protein profile revealed that the isolate was B. burgdorferi. Similarly, a 2-year-old Labrador retriever dog developed neurological signs after tick bite and showed a positive IgG antibody titer against B. burgdorferi. Antibiotic treatment was effective also in this case. These findings suggest that neurological symptoms shown in both dogs were caused by infection with B. burgdorferi.

Animals↗

PubMed1993

Similarity in nucleotide sequence of the gene encoding nontoxic component of botulinum toxin produced by toxigenic Clostridium butyricum strain BL6340 and Clostridium botulinum type E strain Mashike.

The complete nucleotide and deduced amino acid sequence of the nontoxic component of botulinum type E progenitor toxin is determined in recombinant plasmid pU9BUH containing about 6.0 kb HindIII fragment obtained from chromosomal DNA of Clostridium butyricum strain BL6340. The open reading frame (ORF) of this nontoxic component gene is composed of 3,486 nucleotide bases (1,162 amino acid residues). The molecular weight calculated from deduced amino acid residues is estimated 13,6810.1. The present study revealed that 33 nucleotide bases of 3,486 are different in the nontoxic component gene between C. butyricum strain BL6340 and C. botulinum type E strain Mashike. This corresponds to the difference of 17 amino acid residues in these nontoxic component.

Amino Acid Sequence↗

PubMed1993

Close association between Streptococcus sobrinus in the saliva of young children and smooth-surface caries increment.

Three hundred and thirty-eight children (age range 3-5 years) were examined for the presence of mutans streptococci in their saliva. They were divided into four groups according to the prevalent species that were isolated: (1) Streptococcus mutans and Streptococcus sobrinus group (S. mutans > or = 10(3) CFU/ml and S. sobrinus > or = 10(3) CFU/ml); (2) S. mutans group (S. mutans > or = 10(3) CFU/ml but S. sobrinus < 10(3) CFU/ml); (3) S. sobrinus group (S. sobrinus > or = 10(3) CFU/ml but S. mutans < 10(3) CFU/ml), and (4) children with mutants streptococci absent or barely detectable (mutants streptococci < 10(3) CFU/ml). The previous caries experience was compared among the groups, as was the caries increment during a 6-month period after the bacterial examination. The subjects in the S. sobrinus group had both higher caries and higher decayed teeth and surface increments than the S. mutans group. The mean decayed smooth-surface increment (delta d-surface) for the S. sobrinus group was 2.6 and was significantly higher than 0.8 for the S. mutans group. For the subjects with delta d-surface > or = 4, the mean number of S. sobrinus in the saliva was 4.29 x 10(5) CFU/ml and was significantly higher than 0.32 x 10(5) CFU/ml for the subjects without delta d-surface. There was no significant difference in the mean number of S. mutants in saliva between the subjects with and without delta d-surface. The prevalence of S. sobrinus in saliva was more closely associated with future caries activity, especially with smooth-surface caries increment, than the prevalence of S. mutants.

Analysis of Variance↗

PubMed1993

Serological survey for Borrelia burgdorferi infection in cattle in southern Hokkaido.

By means of the enzyme-linked immunosorbent assay (ELISA), antibodies to Borrelia burgdorferi were examined in 970 cattle from southern Hokkaido, Japan. The seropositivity rate in the cattle less than 2 years old differed significantly from that in those 3 years old or more. A seasonal variation was also observed in the rate of seropositivity to B. burgdorferi. High levels of anti-B. burgdorferi antibody were detected even in sera from a healthy group of cattle, indicating that there are likely to be many inapparent cases of B. burgdorferi infection. This article discusses the syndromes associated with Lyme borreliosis and addresses the issues of diagnosis and treatment in animals.

Animals↗

PubMed1993

[Experimental animal models in Mongolian gerbils and mice].

Helicobacter pylori is an emerging candidate agent for the genesis of chronic gastritis and peptic ulcer. There have been many challenges to establish an experimental infection with H. pylori in animals. In recent, several studies reported for animal infection with this organism. One of them was the study using urinary system. The study indicated the ability of H. pylori to induce inflammation without significant low pH condition. Experimental infection in Mongolian gerbils showed that H. pylori could colonize on the surface of the gastric mucosa in animals without human. The study of nude mice by Karita et al. showed several valuable facts concerning the relation between bacterial pathogenicity and potential of bacterial colonization in stomach. The study in which remaining of bacteria was extended showed that colonization of H. pylori was affected by bacterial flora in the stomach.

Animals↗

PubMed1992

Dipyridamole enhances an anti-proliferative effect of interferon in various types of human tumor cells.

The anti-proliferative activity of human interferon (HuIFN) was enhanced by dipyridamole, 2,6-bis-(diethanolamino)-4,8-dipiperidinopyrimido-[5,4-d]-py rimidine, when tested against various human tumor cell lines, including KT (breast carcinoma), PLC/PRF/5 (hepatoma), MGC-I, U251-SP and T98 (glioma), HAC-2 and SHIN-3 (ovarian carcinoma), and MM-ICB (melanoma). The enhancement occurred irrespective of the kind of HuIFN used (alpha, beta or gamma) and the original degree of susceptibility of the cells to HuIFN. Even low doses down to 0.01 microM of dipyridamole that had no intrinsic anti-proliferative activity could enhance the effect of HuIFN. The enhancement of HuIFN effects seems not to be caused by induction of HuIFN production, because neither anti-viral activity nor HuIFN antigens were detected in culture medium in cells treated with dipyridamole. Mopidamole, a derivative of dipyridamole lacking one piperidine residue, produced little enhancement of the effects of HuIFN. Among ovarian cancer cell lines tested, the enhancement of the activity of HuIFN by dipyridamole for HAC-2 and SHIN-3 cells was equivalent to or greater than that for 3 chemotherapy agents (adriamycin, vincristine, and a camptothecin derivative). However, neither HOC-21 ovarian cancer cells nor HEC-1 endometrial adenocarcinoma cells were susceptible to any combinations. When MGC-1, U251-SP, and HAC-2 cells were injected into nude mice, the growth of tumors was more markedly inhibited by the subcutaneous administration of HuIFN in combination with oral administration of dipyridamole than by the HuIFN alone. Thus, this combination therapy seems to be worth trying for human cancer, although the enhancement of the effects of HuIFN by dipyridamole varied among the cell lines examined.

Animals↗