PubMed Health⌕ Search

Biomedical subjects

F Mudawwar

Publications and source records attributed to F Mudawwar.

7 recordsLinked to original sources
PubMed1983

Immunologic patterns in hemodialysis patients with and without HBV infection.

66 patients from 5 dialysis centers were surveyed for the prevalence of HBV markers. Their immune status was evaluated by studying parameters of cellular and humoral immunity. Results showed that all patients had depressed T cell numbers while B cell counts, IgG, IgA, IgM, IgD and C3 levels were normal. However, the group of patients who had persistent HBs antigenemia also had persistence of HBeAg, negative responsiveness to skin testing and high IgE levels. The group with HBsAb had negative reactions for skin testing, and the group with no HBV markers had no further abnormalities. These results suggest that the presence and type of HBV marker influences the immune pattern in the hemodialyzed patient.

Adolescent↗
PubMed1982

Autoanti-idiotypic lymphocytes in man.

Cells with anti-idiotypic properties were detected 4-6 months following immunization with tetanus toxoid (TT), and were undetectable 10 days following a booster injection. The presence of these cells concomitantly with the normal drop of anti-TT serum titers, and their specific binding to autologous IgG--F(ab')2 anti-TT, suggests a negative feedback at the idiotypic network level.

Antilymphocyte Serum↗
PubMed1980

Regulation of monoclonal immunoglobulin G synthesis by antiidiotypic antibody in a patient with hypogammaglobulinemia.

The regulation of in vitro antibody synthesis by antiidiotypic antibodies was studied in a child with hypogammaglobulinemia and a serum immunoglobulin (Ig)G1 kappa M component. A rabbit antiserum was raised against the purified M component and was rendered idiotype specific by extensive absorption with Cohn fraction II and with IgG derived from the patient's parents. Hemagglutination-inhibition studies demonstrated that less than 1 in 300,000 molecules of pooled human IgG carried M component-related idiotypic determinants. 12% of the patient's B cells, but none of her T cells, expressed idiotypic determinants on their surface. Spontaneous de novo synthesis of the M component by the patient's peripheral blood lymphocytes was demonstrated in vitro and was shown to proceed independently of the polyclonal activator pokeweed mitogen. Antiidiotypic rabbit IgG, but not its F(ab')2, fragments, profoundly inhibited the synthesis of M component by the patient's peripheral blood lymphocytes. We concluded that antiidiotypic antibodies may play a role in the regulation of antibody synthesis in man.

Agammaglobulinemia↗
PubMed1977

The specificity of T-cell helper factor in man.

Supernates of human T cells stimulated with TT antigen contain a factor that induces mitogenesis and immunoglobulin synthesis in autologous as well as allogeneic B cells. A fraction of the IgG produced has specificity against TT. The T-cell-derived LMF-TT eluted after albumin on Sephadex G 200 and did not contain immunoglobulin heavy chain determinants. LMF-TT was active on B cells from TT immune as well as TT- nonimmune individuals but in the latter instance the IgG secreted had no specificity against TT. B cells incubated with LMF-TT in the presence of a second antigen (DT) made IgG with specifity to that antigen provided the B-cell donor was immune to that second antigen. LMF-TT-containing supernates were depleted of TT antigen by Sephadex G 200 chromatography followed by passage over anti-TT immunosorbent columns. The antigen-free supernates were able to induce mitogenesis and IgG synthesis in B cells but the IgG produced failed to exhibit specificity against TT unless the TT antigen was readded to the B-cell cultures. The optimal concentration of LMF-TT (50 percent) inducing B-cell mitogenesis was different from the optimal concentration (20 percent) causing IgG synthesis by B cells. At low LMF concentrations (less than or equal 10 percent) addition of a second antigen to which the cell donor was immune caused an increase in the degree of B-cell mitogenesis. Submitogenic concentrations of LMF-TT (less than or equal to 5 percent) were still capable of inducingimmunoglobulin synthesis in B cells At these low concentrations of LMF-TT the proportion of anti-TT IgG over total IgG increased sharply. B cells from TT immune donors were separated on TT immunosorbent columns. Cells that bound to the column were more sensitive to the mitogenic and IgG synthetic effects of LMF-TT than unfractionated B cells. Thus, LMF is a nonspecific human T-cell helper factor which behaves like a polyclonal B-cell activator. However, in the presence of specific antigen (TT) the antigen-specific B cell is preferentially triggered by LMF. The experimental design of the present study does not rule out the additional presence of an antigen-specific helper factor in the supernates of TT-stimulated human T cells.

Antibody Formation↗