ISSN:0300-5526    

DOI:10.1159/000150178

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Lactococcal phages are classified according to morphology and DNA homology. Phages are differentiated into 12 phage species, and type phages of each species are proposed. Members and possible members of each species are named. Available data on type phages are tabulated including morphology, DNA characteristics and phage protein bands.

ISSN:0300-5526    

DOI:10.1159/000150179

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Investigation into the presence of human cytomegalovirus (HCMV) transforming mtrll and mtrlΠ sequences in peripheral blood lymphocyte (PBL) specimens of AIDS and high-risk patients was carried out by nucleic acid hybridization analyses. These probes were selected because they were viral-specific and lacked homology to normal cellular DNAs. In Southern blot hybridizations carried out under stringent conditions, we detected HCMV mtrll sequences associated with the high-molecular-weight DNAs of PBLs in 17 of 37 patients either with AIDS/Kaposi’s sarcoma or at high risk for AIDS. In comparison, only 2 of 17 DNA specimens from PBLs of healthy blood donors showed hybridization to mtrll sequences. The inability to detect hybridization to the mtrlΠ region in most mtrII-positive specimens suggested a specific retention of mtrll sequences. Our study suggests that the retention of mtrll sequences in high molecular weight DNA may constitute a risk factor for the development/ progression of AIDS. Alternatively, the retention of mtrll sequences may occur as a result of enhanced HCMVreplicationin patients with AIDS or at high risk for A

ISSN:0300-5526    

DOI:10.1159/000150180

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The relationship between maize streak virus and the geminivirus causing streak in sugarcane was investigated. The DNA of sugarcane streak virus does not cross-hybridize detectably with that of maize streak virus and vice versa. Restriction mapping of native replicative form viral DNA (genome size 2.7 kb) and of cloned viral DNA, combined with limited sequencing and estimated DNA sequence divergence, showed that sugarcane streak virus is as unrelated to maize streak virus and digitaria streak virus as these are different from each other. The virus is only distantly related to wheat dwarf virus and chloris striate mosaic virus. Based on these results, we propose that the agent causing sugarcane streak is a distinct geminivirus.

ISSN:0300-5526    

DOI:10.1159/000150181

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

Immune inhibition of release of the DNA viruses, herpes simplex virus types 1 and 2 and pseudorabies virus by anti-viral and anti-host cell sera occurred while two RNA viruses, influenza and encephalomyocarditis, were inhibited only by anti-viral sera (not anti-host cell sera). Simian virus 40 and surprisingly two herpes viruses, bovine mamillitis and equine abortion, were not inhibited by either anti-viral or anti-host sera. Using the herpes simplex virus model, inhibition of virus release was detected in different cells of human and nonhuman origin with cross-inhibition between cell lines of different origin; thus, this form of immunotherapy may not require antibody to be tissue or organ specific. Evidence of inhibition of virus release from neoplastic and leukemic cell lines suggests possible application of this approach to control of virus-mediated leukoproliferative pathology (e.g. Burkitt’s lymphoma or adult T cell leukemia

ISSN:0300-5526    

DOI:10.1159/000150182

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The effect of human serum with or without Epstein-Barr virus (EBV) antibodies was characterized on virus production in P3HR-1 cells. Cell culturing with EBV-seropositive sera reduced both production of infectious virus and amounts of virion DNA in the supernat-ants. EBV DNA was also reduced in the cells. Such reductions in cell-associated EBV DNA depended upon the concentration of seropositive serum and incubation time. Decreased frequencies of productive EBV DNA-replicating cells were observed in cell populations which had reduced levels of cell-associated EBV DNA. The inhibitory effect of seropositive serum was reversed upon switching the cells to medium with seronegative serum. In serial sera of an acute infectious mononucleosis patient the EBV DNA-reducing activity arose in parallel to antibodies against EBV membrane antigen and nuclear antigen. Possible mechanisms were discussed for antibody-mediated inhibition of EBV production.

ISSN:0300-5526    

DOI:10.1159/000150183

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

The specificity of serum antibodies from patients with subacute sclerosing panencephalitis (SSPE) and seropositive controls to measles virus proteins produced in acutely and persistently infected human cells was examined by western blot analysis. Sera from both SSPE patients and controls reacted to the H, N, and F1 virus proteins produced in acutely infected AV3 cells. However, while SSPE-derived sera reacted with the same proteins in persistently infected cells (AV3A1/MV), most control sera failed to react with the hemagglutinin protein produced in such cells (Hp). Most sera also reacted poorly with the M protein from either source, and the reactivity to the P protein was variable. Although the exact reason(s) for the different reactivities to the proteins were not determined, differences in antibody concentration did not appear to be responsible. The dramatic differences in the reactivity of SSPE and control sera to the Hp protein suggest that either the protein coevolves in persistent infections or multiple forms of the protein evolve in such infections and SSPE patients develop broad-spectrum humoral immunity as a consequence of exposure to them. Alternatively, over time there may be selective loss of some H-reactive antibody subsets by individuals who contract measles, but do not develop SSPE.

ISSN:0300-5526    

DOI:10.1159/000150184

出版商:S. Karger AG    

年代:1991

数据来源: Karger

摘要:

LDV/7, H9, and MOLT-4, three cell lines infectible by human immunodeficiency virus were incubated with dimethyl sulfoxide, an inducer of cell differentiation. It was shown that this is a powerful inhibitor of viral production, but its effect is transient: viral production resumes when the compound is removed from the culture medium. It does not inactivate the virus, and it fails to prevent viral infection or to inhibit expression of p24 on the surface of the infected cells.

ISSN:0300-5526    

DOI:10.1159/000150185

出版商:S. Karger AG    

年代:1991

数据来源: Karger