Biken journal最新文献

One of the authors (Y.O.), who had previously been immunized with Japanese encephalitis (JE) vaccine, showed symptoms of typical dengue fever 6 days after accidental infection with a newly isolated dengue type 4 virus strain from a patient with dengue hemorrhagic fever (DHF) in Thailand. His sera were examined by hemagglutination inhibition (HI), complement fixation (CF) and neutralization (N) tests. The JE N antibody titers of his sera were high even on the first day of the illness and remained almost constant during the next year. Antibodies that reacted with dengue viruses were detected from a very early stage of the illness by all three serological tests. In addition, his convalescent phase sera showed high titers against all 4 types of dengue virus. These data suggest that the dengue infection caused secondary stimulation of antigens of flavivirus. Sedimentation analysis of antibodies in Y.O.'s serum (day 9) was carried out and IgM antibody that reacted only with dengue type 4 virus and homologous infecting virus was separated. These findings clearly demonstrated that the laboratory infection of Y.O. was primary dengue infection with dengue type 4 virus.

We have synthesized vial-specific transcripts in nuclei isolated from cells infected with the parvovirus Kilham rat virus. Radioactive vial-specific RNA synthesized in the nuclei was extracted, hybridized to viral DNA, incubated in glyoxal, and electrophoresed in an agarose gel. At least five viral-specific RNAs were detected containing 4.6 Kb (25-26S), 3.2 Kb (major species, 20-22S), 2.9 Kb, 1.3 Kb, and 1.0 Kb pairs. The 4.6 Kb RNA represents a transcript of 95-100% of the viral genome. The major 3.2 and 2.9 Kb RNAs represent a transcript of 50-60% of the viral genome. Over 65% of the viral-specific RNA in the isolated nuclei is polyadenylylated on the 3' terminus. The 5' terminus of the RNA is capped in vitro by the sequence m7G(5')ppp(5')A. Incorporation of [beta-32p]ATP into the 5' cap sequence suggests that initiation of viral RNA synthesis may occur in the infected isolated nuclei.

In order to identify the specific and cross-reactive antigens to Marek's disease virus (MDV) and herpesvirus of turkeys (HVT), we prepared hybridomas producing monoclonal antibodies against these viruses. These monoclonal antibodies were screened by the indirect immunofluorescence method. The purified virus-specific antigens appeared to be more effective immunogens than unpurified virus-infected cell homogenates. Totals of 50 and 14 hybridoma clones were found to produce antibodies specific to MDV and HVT, respectively. Of these, 14 MDV clones and 5 HVT clones produced antibodies that recognized antigenic sites common to both viruses.

The heterophile antibody levels in sera from patients with Kawasaki disease (49 sera from 39 cases) were measured by sheep erythrocytes (SRBC) agglutination and radioimmunoassay in microplates coated with Hanganutziu-Deicher (H-D) antigen-active glycosphingolipid, equine hematoside. The antibody levels were low in the first week of illness, increased rapidly in the 2nd week, and thereafter gradually decreased. The SRBC agglutination titers and H-D antibody titers of sera from patients with Kawasaki disease from week 2 to 8 of illness were significantly higher than those of healthy children (44 sera) and normal cord blood (13 sera).

A double-blind, controlled trial to ascertain the preventive effect of human interferon-alpha (Hu IFN-alpha) on upper respiratory viral infections was performed on children in a closed community. Drops of Hu IFN-alpha were instilled into the nasal cavity of 13 healthy children aged one to three years. Fourteen children were given placebos as controls. Administration of the interferon and clinical observations were carried out in the winter of 1980. Serological examination revealed that this was the period of outbreaks of influenza type A epidemics in the community. Clinical manifestations referable to influenza virus infection were milder in the interferon-treated group than in the controls. However, there was no significant difference in the serological responses of the two groups after infection with influenza virus type A.

Deoxythymidine kinase (TK) activity induced in varicella-zoster virus (VZV)-infected human embryonic fibroblast (HEF) cells was immunologically distinguishable from that in non infected HEF cells and also from that in herpes simplex virus type 1 (HSV-1) infected HEF cells. The TKs in VZV-biochemically transformed cells were immunologically the same as that induced in VZV-infected human cells and immunologically different from that in Ltk- cells or in HSV-biochemically transformed cells. One peak of TK activity with an Rm value of 0.8-0.9, corresponding to mitochondrial TK, was observed on polyacrylamide gel electrophoresis of Ltk- cell extracts. VZV infected Ltk- cells had two peaks of TK activity with Rm values of 0.45-0.5 (peak I) and 0.8-0.9 (peak II). Peak I and II were concluded to be virus-specific TK and mitochondrial TK, respectively. VZV-biochemically transformed cells had a peak of activity with an Rm value of 0.4-0.5, corresponding to peak I in VZV-infected Ltk- cells; that is VZV-specific TK activity. The present study indicates that VZV has a gene coding for its own TK.

The requirements for nusA and nusB gene products for the effective transcription of E. coli genes, including the trp operon, were demonstrated by analysis of RNA transcripts produced in nusA, nusB and nusAnusB mutants. In the nusA1 mutant, the levels of overall synthesis of both bulk RNA and trp mRNA were reduced more at 37 C than at 30 C, consistent with the idea of temperature-sensitive nus protein function (Friedman et al., 1973). In the nusB27 and nusA1nusB27 mutants (Friedman et al., 1976), decrease in the overall rates of these RNA synthesis was notable even at 30 C. In nus mutants harboring trp delta LD1412, in which the trp operon attenuator site is deleted, the reduction in the trp mRNA level was less severe. Thus, the effect of nus mutations seems to result in part from more frequent transcription termination at the attenuator site. Also in nusA1nusB27 mutants, in which the distal portion of the trp operon is deleted, the trp mRNA level was not reduced much. Thus, transcription in the nus- mutants seems to be frequently and prematurely arrested at sites along the trp operon.

One of the authors (Y.O.) of this paper was accidentally infected in the laboratory with dengue type 4 virus, isolated in Thailand in 1978 using the C6/36 clone of Singh's Aedes albopictus cells (SA). Two strains of the virus were isolated from Y.O.'s serum on the first day of illness using SA and suckling mouse brain (SMB). The SA-isolate and the infecting virus were neutralized with high efficiency by Y.O.'s convalescent sera, but the SMB-isolate was neutralized much less efficiently by the same sera. When the hosts of the isolates were exchanged (SA to SMB, and vice versa), the neutralization efficiencies were reversed. For analysis of this phenomenon, prototype dengue type 4 virus exclusively passed in SMB and the same type of virus passaged 10 times in SA were compared with the initial SA- and SMB-isolates in neutralization tests with sera from patients with dengue hemorrhagic fever (DHF) obtained in Thailand. The two strains of the prototype virus and the SA-isolate had similar high reactivities, but the SMB-isolate had low reactivity with sera of the DHF patients.

A specific heteroantiserum was prepared against the leukemic cells from a patient with T-derived chronic lymphocytic leukemia (T-CLL). The anti-serum was absorbed with cells of a morphologically different type from another patient with T-CLL. Both the immunizing cells and absorbing cells had Fc receptor for IgG (Fc gamma R), so the former case was named T gamma-CLL type 1, and the latter T gamma-CLL type 2. This antiserum, termed anti-T gamma-1, reacted with 19% of normal peripheral blood T lymphocytes, but not with non-T lymphocytes or monocytes. The T lymphocytes in the blood that reacted to anti-T gamma-1 were 72% of the T gamma cells. Anti-T gamma-1 also reacted to 60-78% of the thymocytes. Except for T gamma-CLL type 1 cells, anti-T gamma-1 did not react with various types of leukemia cells from lymphoid malignancies, myelogenous leukemias and monocytic leukemias. Studies on the relation between anti-T gamma-1 and OKT8 monoclonal antibody revealed that anti-T gamma-1 reactive (anti-T gamma-1+) cells and OKT8+ cells largely overlapped, but they were different in part. More interestingly, OKT8 inhibited Fc gamma R binding, but anti-T gamma-1 did not. These results indicate that anti-T gamma-1 is useful for detecting a certain subset of T cells and for classifying lymphoproliferative disorders.

Various combinations of four substrains of Staphylococcus aureus L-form (strain STA-EMT-1), each of which was resistant to one of the following four drugs, streptomycin (SM), tetracycline (TC), chloramphenicol (CP) and erythromycin (EM), were submitted to polyethylene glycol (PEG)-induced cell fusion. PEG-induced cell fusion followed by enrichment culture in the liquid basal medium supplemented with penicillin G resulted in development of recombinants that were doubly drug-resistant to SM and TC, SM and CP, and TC and CP, but no recombinant doubly resistant to EM and TC, was obtained by treatment of a EM-resistant and TC-resistant substrains with PEG. No recombinants resistant to SM, CP and TC could be obtained by treatment of substrains resistant to SM, CP and TC, respectively, with PEG. But recombinants triply resistant to these three drugs were produced by two-step cell fusion; that is by fusion of a recombinant doubly resistant to two of the three drugs with a substrain resistant to the third drug.