Hepatitis non-A,non-B.

Evidence for the existence of hepatitis non-A, non-B includes epidemiologic data and results of transmission studies indicating the presence of hepatitis that could not be explained by known causative agents. The diagnosis is suggested in patients who have multiple episodes of acute hepatitis or who contract hepatitis after transfusion, hemodialysis or drug abuse. Sporadic cases are common. Three such cases are described to illustrate that the disease is clinically indistinguishable from hepatitis A or B. The diagnosis is based on the absence of serologic markers of hepatitis A and B and of infection by Epstein-Barr virus and cytomegalovirus, or on serologic evidence of previous infection with hepatitis A and B.     

The epidemiological patterns of hepatitis non-A, non-B

The etiological structure of viral hepatitides in three cities of the Volga region was studied. The proportion of hepatitis non A, non B was established: it varied from 3.6% to 18.1% at different territories and depended on the total morbidity level, on the season, as well as on the age of patients. A suggestion was made concerning the role of the parenteral mechanism of the transfer of hepatitis non A, non B at the territory under study.     

Association of human hepatocellular membrane fusions with non-A, non-B hepatitis

Liver biopsies from patients with alcoholic hepatitis, chemical hepatitis, or viral hepatitis types A, B, or non-A, non-B were examined by electron microscopy. Circular, fused, cytoplasmic membranes were observed in hepatocytes of 17% of patients with hepatitis type B and 92% of patients with hepatitis type non-A, non-B. The membrane alterations were not observed in hepatocytes of patients with the other types of hepatitis. The greater frequency of altered cytoplasmic membranes in hepatocytes of patients with non-A, non-B hepatitis was shown to be statistically significant (p less than 0.05) when compared to that in patients with viral hepatitis type B.     

Inhibition of fertility in rabbits by monoclonal antibodies against sperm

Monoclonal antibodies were prepared against rabbit sperm antigens by fusing P3-X63-Ag8-653 mouse myeloma cells with lymphocytes from Balb/c mice immunized with Tergitol NP-40 detergent-solubilized rabbit epididymal sperm. Ascites fluid from mice injected with two of these hybridomas (8C4.1 and 8C10.5) was negative in immobilization and agglutination methods, however, acrosome positive on methanol fixed sperm and plasma membrane positive on unfixed sperm in indirect immunofluorescence. Insemination of female rabbits with the sperm treated with either of these monoclonal antibodies resulted in significant reduction in fertility as seen by the percentage of 9-day implants/corpora lutea ratio (8C4.1, 25.7%; 8C10.5, 1.9%; and control, 64.7%). Though the antibodies inhibited in vitro binding of the rabbit sperm with zonae pellucidae of rat ova, fertilization in vivo was not affected significantly. The antibodies did not demonstrate antiblastocyst activity by immunofluorescence. Both of these monoclonal antibodies appeared to recognize the same antigen by the SDS-PAGE/Protein Blot enzyme immunobinding procedure. The antigen was of testicular origin and had a molecular weight of approximately 63,000 daltons. It is concluded that these monoclonal antibodies which were organ specific, block post-fertilization fertility by inhibiting some step necessary for viable embryo formation.     

A cDNA clone closely associated with non-A, non-B hepatitis.

A lambda gt11 cDNA library was constructed from RNA purified from hepatitis B viral surface antigen-negative human plasma with high alanine aminotransferase activity. A cDNA clone, designated as C8-2, was isolated by immunoscreening with mixed sera from non-A, non-B hepatitis (NANBH) carrier and convalescent chimpanzees. The recombinant protein produced by C8-2 reacted specifically with sera of patients in the chronic phase of NANBH. The sequence of C8-2, 269 bp, did not hybridized with any human or chimpanzee genomic DNA, and had no homology with those of primates and viruses. The existence of this sequence in RNA of possibly infectious plasma was shown by RNA blot hybridization and by Southern blot analysis of products amplified by the polymerase chain reaction. These results strongly suggest that C8-2 is derived from the agent of this viral hepatitis.     

Characterization of Shigella flexneri-specific murine monoclonal antibodies by chemically defined glycoconjugates

Chemically defined glycoconjugates are demonstrated to have considerable potential for selecting hybridoma antibodies directed toward O-antigenic determinants, especially when used in combination with a panel of well-characterized LPS molecules. Monoclonal antibodies specific for the Shigella flexneri O-antigens of serogroup 5b, variants X and Y, were generated after immunization of BALB/c mice with killed bacterial cells, and active hybrids were selected on the basis of ELISA performed with the purified serotype-specific LPS antigen. Subsequent screening with a variety of glycoconjugates, derived from synthetic oligosaccharides and larger structures obtained by phage Sf6/endo-rhamnosidase hydrolysis of purified LPS established a detailed profile of binding characteristics for Shigella flexneri variant Y-specific antibodies. Together with the results of precipitin analysis and heavy chain isotyping experiments, a limited number of antibodies were selected as candidates for detailed studies of the antibody combining site.     

Cloning and expression of cDNAs from enterically-transmitted non-A, non-B hepatitis virus.

The fragment gene of enterically-transmitted non-A, non-B hepatitis virus (ET-NANBHV) was cloned as a cDNA and inserted into an expression vector pUEX2. The recombinant protein was expressed in Escherichia coli HB101 as a fusion protein with beta-galactosidase (beta-Gal). The fusion protein reacted with the sera of infected cynomolgus monkeys and of patients from Myanmar. This reaction was highly related with ET-NANBHV infection, and obviously demonstrates in that the recombinant protein can be used for the detection of ET-NANBHV infection.