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Biomedical subjects

Y Minamishima

Publications and source records attributed to Y Minamishima.

At least 73 records · Page 4Linked to original sources
PubMed1989

Immunological and molecular comparison of simian cytomegaloviruses isolated from African green monkey (Cercopithecus aethiops) and Japanese macaque (Macaca fuscata).

Simian cytomegaloviruses (CMV) isolated from African green monkeys and Japanese macaques were compared serologically and genetically. Twenty-three out of 31 sera from Japanese, Taiwan and rhesus macaques were positive for neutralizing antibodies to simian CMVs isolated from both African green monkeys and a Japanese macaque. The neutralizing antibody titers of those sera were slightly higher to the isolates of African green monkeys origin than to that of Japanese macaque origin. Studies with antisera prepared in guinea pigs revealed a partial antigenic cross-reaction between Japanese macaque CMV (JaM-CMV) and African green monkey CMV (AGM-CMV): the antiserum to JaM-CMV neutralized both homologous JaM-CMV and heterologous AGM-CMV, but the antisera to AGM-CMV neutralized only homologous AGM-CMV. DNAs of both AGM-CMV and JaM-CMV were compared by restriction endonuclease cleavage analysis. The individual simian CMV isolates showed unique restriction patterns when cleaved with EcoRI, BamHI, or HindIII. In addition, DNA of JaM-CMV was distinguishable from that of AGM-CMV when cleaved with EcoRI or BamHI.

Animals↗
PubMed1989

Induction of resistance in mice against murine cytomegalovirus by cellular components of Lactobacillus casei.

Recently, we reported that heat-killed Lactobacillus casei (LC) protected mice from murine cytomegalovirus (MCMV) infection by augmentation of natural killer (NK) cell activity. In the present study, we examined which components of LC cell induce the nonspecific resistance most effectively. Whole cell preparation of original LC, susceptible to bacteriophages SG-T and J1, was more effective than its mutants resistant to either bacteriophage. Although the activity of LC cells decreased upon fractionation, cell wall fractions were more active than cytoplasmic fractions. Glycoprotein (GP), a cell wall constituent, was a potent inducer of the resistance. The relative activity of cellular components to induce the resistance was evaluated by a protection index, a ratio of plaque-forming units (PFU) per 50% lethal dose (LD50) for treated mice to that for untreated mice. The protection indices of LC cells and GP were approximately 80 and 28, respectively. The protective effect of GP was evidenced by a decrease in titers of infectious viruses replicated in the target organs. Not only LC cells but also GP, although to a lesser degree, enhanced NK cell activity both in uninfected mice and MCMV-infected mice. The activity of LC cells and GP to augment NK cell activity correlated with the protection index. GP treatment did not modify interferon (IFN) production during MCMV infection. Thus, GP of LC cells seems to be the active principle to endow mice with resistance to MCMV.

Animals↗
PubMed1989

Prevalence of cytomegalovirus antibodies in Brazilian and Japanese populations in the north-east of Brazil.

The serological status to cytomegalovirus (CMV) was examined for 616 Brazilians and 399 Japanese immigrants living in the North-East of Brazil. The sera were screened for IgG antibodies to CMV by enzyme-linked immunosorbent assay (ELISA). The overall prevalence of CMV antibodies was higher in the Japanese population (83.7%) than in the Brazilian population (69.8%). The seropositivity was analyzed by factors of age, sex, ethnic background, and socioeconomic status. Mother-baby contact seems to be a factor of significance in the seroepidemiology of CMV infection.

Adolescent↗
PubMed1989

[Antigenic types of Rickettsia tsutsugamushi isolated from patients with tsutsugamushi fever and their distribution in Miyazaki Prefecture].

Rickettsia tsutsugamushi (Rt) isolated from patients with tsutsugamushi fever were examined for their antigenicity. This was done by indirect immunofluorescence (IIF) with guinea pig antisera against three standard strains (Karp, Kato and Gilliam) and two local strains (Kawasaki and Kuroki) isolated in 1981, and with mouse monoclonal antibodies against the three standard strains. In the meantime, antibodies in sera from 317 out of 442 patients registered during 1985 to 1988 were titrated by IIF with those five Rt strains. 1) Local isolates, Kawasaki and Kuroki strains, reacted most effectively with the homologous antiserum, respectively, showing four fold lower IIF titers against the heterologous antisera. 2) Kawasaki strain reacted with none of the monoclonal antibodies, whereas Kuroki strain showed a slight reaction with anti-Karp and anti-Kato, but not anti-Gilliam, monoclonal antibodies. 3) Seventeen out of 27 strains isolated in 1985 resembled the Kawasaki strain in their reaction patterns with the antisera and monoclonal antibodies, and the other 10 strains showed reactivity similar to the Kuroki strain. 4) Sera of 233 (74%) out of 317 patients showed the highest antibody titers against the Kawasaki strain and 69 (22%) of 317 against the Kuroki strain. It is thus evident that Kawasaki and Kuroki strains are antigenically different from the standard strains, and Kawasaki and Kuroki strains also differ from each other. It is suggested that two antigenic types (Kawasaki and Kuroki) of Rt were distributed in Miyazaki Prefecture, Rt of the Kawasaki type slightly dominates Rt of the Kuroki type, and recent tsutsugamushi fever has been caused by either one or the other type of Rt.

Antigens, Bacterial↗
PubMed1989

[Efficacy of ganciclovir against cytomegalovirus nephropathy after kidney transplantation].

A 32-year-old man who had received a kidney transplant from a living related donor, contracted cytomegalovirus (CMV) pneumonitis in the 8th month. He was treated with human interferon-beta and cured of the pneumonitis. After that, his serum creatinine value increased gradually. Renal biopsy revealed the cells with intranuclear inclusion bodies in the renal tubulus and the cells were positive for CMV antigens by direct immunofluorescence test using FITC-labeled mouse monoclonal antibody against an early antigen. He was hospitalized with persistent CMV viruria and treated with ganciclovir. Ganciclovir was administered daily in doses of 3 mg per kg per day for 32 days by intravenous drip infusion and thereafter the same dose was given 3 times weekly for 8 weeks. His urine was positive for CMV before the ganciclovir treatment and became negative on the 31st day after the treatment. The anti-CMV effect of ganciclovir was evidenced by gradual decrease in titer (PFU) of infectious CMV in the urine samples. His serum creatinine value decreased from 3.2 mg/dl to 2.8 mg/dl, and no adverse effect was noticed. Thus, ganciclovir is considered to be efficacious against CMV infections in kidney transplant recipients.

Adult↗
PubMed1988

Effect of natural human interferon-beta on the replication of human cytomegalovirus.

The antiviral effect of natural human interferon-beta (HuIFN-beta) against human cytomegalovirus (CMV) was evaluated in human embryonic lung fibroblasts (HEL). Natural HuIFN-beta, like other HuIFNs, inhibited the replication of CMV. Pretreatment of the cells with natural HuIFN-beta inhibited the appearance of immediate-early antigen (IEA) or pre-early nuclear antigen (PENA) as well as the production of infectious CMV. After a single treatment with natural HuIFN-beta, intracellular 2', 5'-oligoadenylate (2-5A) synthetase activity was induced and maintained at a high level for several days. The anti-CMV effect of natural HuIFN-beta correlated with the intracellular 2-5A synthetase activity.

2',5'-Oligoadenylate Synthetase↗
PubMed1988

Susceptibility of W/WV mice to murine cytomegalovirus infection.

The susceptibility of congenitally anemic W/WV mice to infection with murine cytomegalovirus (MCMV) was examined. W/WV mice showed a higher mortality rate and shorter survival time after MCMV infection than did their +/+ littermate mice. In addition, W/WV mice showed a lower plaque-forming unit (PFU) per 50% lethal dose (LD50) and produced higher titers of infectious virus in various organs. The mortality rate and survival time of W/WV mice which received a bone marrow graft 4 weeks before infection was completely restored to the level for +/+ mice, suggesting the importance of the cells of myeloid origin. Although natural killer (NK) activity of W/WV mice was comparable to that of +/+ mice before infection, marked reduction was observed after MCMV infection. Furthermore, OK-432 treatment failed to enhance NK activity of W/WV mice. Impaired NK response was also completely restored by bone marrow grafting 4 weeks before infection. The level of serum interferon (IFN) of infected or uninfected W/WV mice was comparable to that of +/+ mice. Therefore, impaired NK inducibility seems to be responsible, at least in part, for the high susceptibility of W/WV mice to MCMV infection.

Animals↗
PubMed1988

Host-mediated antiviral activity of Lactobacillus casei against cytomegalovirus infection in mice.

The protective effect of heat-killed Lactobacillus casei (LC) against murine cytomegalovirus (MCMV) infection was examined. ICR mice treated once with LC 1 day or 2 days before challenge survived lethal infection, but untreated or Lactobacillus fermentum (LF)-treated mice did not. The protective effect was evidenced by an increase in plaque-forming units (PFU) per 50% lethal dose (LD50) and a decrease in titers of infectious viruses replicated in the target organs. This was further confirmed by severity of histopathological damage to the target organs, especially the liver. LC neither inactivated MCMV nor inhibited its replication in mouse embryonic fibroblasts (MEF). The spleen cells from LC-treated mice inhibited its replication in MEF on co-cultivation. Augmentation by LC of splenic natural killer (NK) cell activity correlated with survival of mice from otherwise lethal MCMV infection. Cytotoxic activity of peritoneal cells and level of serum interferon (IFN) were elevated after MCMV infection, but they were not associated with survival of mice nor with treatment of LC. The protective effect of LC was not clear in NK-deficient beige mutant (bgJ/bgJ) mice, when compared with that in their littermate (bgJ/+) mice. Poor protection of bgJ/bgJ mice by LC treatment correlated with failure to induce NK cell activity by LC treatment in the mutant mice. Thus, it is likely that LC protects mice from MCMV infection by augmentation of NK cell activity.

2',5'-Oligoadenylate Synthetase↗
PubMed1988

Establishment and characterization of rat pancreatic beta cell lines transformed by simian virus 40.

Rat pancreatic beta cells were transformed by simian virus 40 (SV40). The established beta cell lines expressed tumor antigen specific to SV40 and retained the ability to produce immunoreactive insulin (IRI) even at a high passage level. One of 12 transformed beta cell lines, SV-PB1205, was further investigated in vitro and in vivo. Firstly, effects of drugs on replication of the pancreatic beta cells were examined in in vitro experiments. Various drugs increased the uptake of 3H-thymidine into the cells. Those included D-glucose, tetragastrin and secretin. However, such effect was not observed for glucagon and growth hormone. Secondly, the SV40-transformed pancreatic beta cells were transplanted into diabetic rats. This produced such improvement of plasma glucose level at least for 2 weeks. The Significance of those experiments was discussed.

Animals↗
PubMed1988

"Transformation" of human endothelial cells by SV40 virions.

Human endothelial cells derived from the umbilical vein were transformed with SV40 virions. A cell line subcultured for over 60 serial passages was characterized in comparison with its untransformed counterpart which was culturable for less than five passages. The SV40-transformed human endothelial cells, designated SV-HUVEC, were positive not only for tumor (T) antigen specific to the SV40-transformed cell, but also for two markers of endothelial cells, Factor VIII-related antigen and a receptor for Ulex europaeus agglutinin I. By transformation the growth potential of the human endothelial cells was increased and their serum requirement was decreased. The SV40-transformed endothelial cells were, however, unable to form colonies in soft agar or to form tumors in athymic nude mice, although a small nodule was produced at the site of inoculation. Subcultivation of these cells up to the 62nd passage eventually resulted in crisis and loss of further cell division. Thus, the human endothelial cells were transformed by SV40 while retaining certain normal functions but without showing tumorigenicity.

Animals↗
PubMed1988

Effect of recombinant murine interferon-beta on the replication of murine cytomegalovirus.

Pretreatment of mouse embryo fibroblasts (MEF) with recombinant murine interferon-beta (rMuIFN-beta) induced a high level of intracellular 2',5'-oligoadenylate (2-5A) synthetase activity. However, murine cytomegalovirus (MCMV) replicated under such condition, indicating that MCMV is relatively insensitive in vitro to rMuIFN-beta. Thus, there was a dissociation of 2-5A synthetase activity and antiviral activity against MCMV. In contrast to MCMV, the two parameters were closely associated in the case of vesicular stomatitis virus (VSV).

2',5'-Oligoadenylate Synthetase↗
PubMed1988

Interaction of herpes simplex virus type 2 with a rat glioma cell line.

The interaction between herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) and two neural cell lines, mouse neuroblastoma (N1E-115) and rat glioma (C6-BU-1), was investigated. N1E-115 cells were permissive to both types of HSV. In C6-BU-1 cells, on the other hand, all the HSV-1 strains tested so far showed persistent infection, and the infectious virus of HSV-2 strains disappeared spontaneously. The HSV-2-infected C6-BU-1 cells were positive for HSV-2-specific DNA sequences, virus-specific RNA, HSV-2-specific antigens and thymidine kinase activity, when no infectious virus was detected. The HSV-2 was reactivated from those C6-BU-1 cells by superinfection with murine cytomegalovirus (MCMV), but not with UV-irradiated MCMV or human cytomegalovirus. The reactivated HSV-2 was identical to the parental virus, when examined by restriction endonuclease cleavage analysis.

Animals↗
PubMed1988

Evaluation of immunoglobulin G preparations for anti-cytomegalovirus antibodies with reference to neutralizing antibody in the presence of complement.

Eighteen commercially available immunoglobulin G (IgG) preparations were evaluated by various methods for anti-cytomegalovirus (CMV) antibodies. The modifications of immunoglobulin G molecules, such as sulfonation, alkylation, and enzyme treatments, resulted in profound reductions in anti-CMV antibody titers. However, after reversion in vitro, sulfonated IgG preparations which have been shown to be reverted in vivo (Y. Masuho, K. Tomibe, K. Matsuzawa, T. Watanabe, S. Ishimoto, S. Tsunoda, and T. Noguchi, J. Biochem. 79:1377-1379, 1976) restored the anti-CMV antibody titers to levels comparable with those of nonsulfonated IgG preparations. There is no good correlation among the titers tested by different methods. As a method which reflects the biological activities in vivo, the neutralization test in the presence of complement is suitable for the evaluation of IgG preparations.

Antibodies, Viral↗
PubMed1988

Induction of Fc (IgG) receptor(s) by simian cytomegaloviruses in human embryonic lung fibroblasts.

Human embryonic lung (HEL) fibroblasts infected with simian cytomegalovirus (SCMV) were found to bind nonspecifically to the Fc portion of human immunoglobulin (Ig) G (IgG). Binding of IgG to SCMV-infected HEL fibroblasts, but not to uninfected HEL cells, was visualized as cytoplasmic fluorescence by the indirect immunofluorescence test, regardless of the presence of anti-CMV antibodies. The receptor(s) reacted with the IgG class of different species, but not with IgM and IgA. The purified Fc fragment reacted with the receptor(s), but the Fab fragment reacted poorly. The reaction was blocked by pretreatment of infected cells with the Fc fragment, but was not blocked with the Fab fragment. The appearance of the Fc receptor(s) required RNA and protein synthesis, whereas a requirement for DNA synthesis remains to be answered by a more sensitive assay. The development of the Fc receptor(s) was inhibited by 2-deoxy-D-glucose, thus indicating that the Fc receptor(s) may be a glycoprotein(s). The Fc receptor(s) was induced by all strains of SCMV tested so far. These included one laboratory strain (GR2757), four fresh isolates from primary kidney cell cultures of African green monkeys, and four fresh isolates from the salivary glands of the Macaca monkeys captured from the wild in Japan.

Antigens, Differentiation↗