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M Margalith

Publications and source records attributed to M Margalith.

59 records · Page 4Linked to original sources
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Prevalence of specific IgA and IgM anti-HBc antibodies compared with HBV DNA in the sera of HBsAg chronic carriers.

OBJECTIVE: We evaluated the significance of IgA antibodies directed against the hepatitis B virus core antigen (IgA anti-HBc) as a marker for viral replication. STUDY DESIGN/METHODS: Serum samples of 143 hepatitis B surface antigen (HBsAg) carriers and 189 HBsAg-negative subjects were studied. Hepatitis B virus (HBV) DNA was detected by polymerase chain reaction. IgA anti-HBc was determined by a capture enzyme-linked immunosorbent assay developed in our laboratory. The results were compared with those for IgM anti-HBc, which were determined by a commercially available method. RESULTS: IgA anti-HBc was detected in 57 (40%) and HBV DNA in 38 (27%) of the HBsAg carriers. Among the HBsAg-negative subjects, IgA anti-HBc and HBV DNA were detected simultaneously in four samples. All 42 HBV DNA-positive samples were IgA anti-HBc positive. IgM anti-HBc was detected in 27 (64%) of them. CONCLUSIONS: IgA anti-HBc is a sensitive marker for HBV replication, and its absence may exclude HBV replication. The role of IgA anti-HBc in monitoring response to therapy and predicting clinical course is being evaluated.

Biomarkers↗
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HIV-1 IgA specific serum antibodies and disease progression during HIV-1 infection.

OBJECTIVE: To evaluate the role of serum human immunodeficiency virus type 1 immunoglobulin A (HIV-1 IgA) antibodies in the progression of HIV-1 infection in relation to viral load and CD4 cell counts. METHODS: Sequential serum specimens were obtained from 218 homosexual men: 123 HIV-1 seropositives, 24 HIV-1 seroconverters, and 71 HIV-1 seronegatives. HIV-1 IgA antibodies were tested blindly by enzyme-linked immunosorbent assay and Western blot. T-lymphocyte subsets were measured by flow cytometry. Viral plasma load was determined by a sensitive branched DNA assay. RESULTS: HIV-1 IgA antibodies with a titer greater than or equal to 50 were detected among 50% of the seroconverters, 27% of the HIV-1-seropositive asymptomatic subjects, 25% of lymphadenopathy, and 23% of HIV-1-related symptomatic subjects. Among patients with the acquired immune deficiency syndrome, the prevalence of virus-specific IgA antibodies (55%) was significantly higher (p < 0.03) as compared with the HIV-1-seropositive asymptomatic subjects, lymphadenopathy and HIV-1-related symptomatic patients, but not versus the seroconverters (p = 0.8). IgA antibodies to HIV-1 gP160 were the most prevalent among all subjects tested. A significant decrease in CD4 cell counts was observed after HIV-1 seroconversion. Viral load was slightly higher among the seroconverters who demonstrated higher (> or =50) HIV-1 IgA levels. CONCLUSIONS: HIV-1 IgA serum antibodies did not predict the progression of the disease. Correlation between HIV-1 IgA antibodies titer, viral load, and CD4 cell counts was not detected.

Adult↗
PubMedDate not supplied

Plasmid DNA gene therapy: studies with the human interleukin-2 gene in tumor cells in vitro and in the murine B16 melanoma model in vivo.

The plasmid DNA vector pVCL-1102 containing the coding sequence for the human IL-2 gene was evaluated for expression in tumor cells in vitro and in vivo. In vitro transfection of murine B16 tumor cells with pVCL-1102 resulted in the expression of 36,000 IU (5.7 micrograms) of biologically active IL-2/10(6) cells/48 h. In vitro transfection of human tumor lines and primary cultures from human biopsies with pVCL-1102 resulted in the expression of 1,289 to 9345 IU of IL-2/10(6) cells/48 h and 30 to 794 IU of IL-2/10(6) cells/48 h, respectively. In vivo, direct intratumor injection of pVCL-1102 resulted in retention of intact plasmid DNA in the tumor tissue and IL-2 secretion by cell cultures derived from the injected tumors. Formulation of pVCL-1102 with the cationic lipid DMRIE/DOPE inhibited DNA degradation and enhanced in vivo transfection efficiency over plasmid DNA alone. Antitumor activity of the pVCL-1102/DMRIE/DOPE complex was evaluated in a B16 melanoma model in mice. An IL-2-specific effect could not be demonstrated in a subcutaneous model because the intratumor injection of plasmid DNA lacking the IL-2 coding sequence also resulted in a significant reduction in tumor volume. However, an IL-2-specific effect was observed when B16 cells were transfected in vitro prior to implantation into the mouse. Transient transfection of B16 cells with pVCL-1102 rendered the cells less tumorigenic in vivo and produced a significant reduction in tumor volume. These data demonstrate that a plasmid DNA expression vector can be used to deliver the IL-2 gene to tumor cells in vitro and in vivo, resulting in the expression of significant levels of IL-2 protein. These data also illustrate the need for the use of appropriate controls when evaluating the in vivo biological activity of plasmid DNA in murine tumor models.

Animals↗