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Biomedical subjects

R S Rosen

Publications and source records attributed to R S Rosen.

9 recordsLinked to original sources
PubMed1993

Defective expression of the CD40 ligand in X chromosome-linked immunoglobulin deficiency with normal or elevated IgM.

B lymphocytes from patients with X chromosome-linked immunoglobulin deficiency with normal or elevated serum IgM are unable to switch from the synthesis of IgM/IgD to that of other immunoglobulin isotypes. Isotype switch recombination was evaluated in three affected males by examining interleukin 4-driven IgE synthesis. T-cell-dependent IgE synthesis was completely absent in the B lymphocytes of the patients. In contrast, CD40 mAb plus interleukin 4 induced the patients' B cells to synthesize IgE and to undergo deletional switch recombination. Because interaction between CD40 and its ligand on activated T cells is critical for T-cell-driven isotype switching, we examined CD40 ligand expression. In contrast to normal T cells, lymphocytes from the patients expressed no detectable CD40 ligand on their surface after stimulation with phorbol 12-myristate 13-acetate and ionomycin, although the mRNA of the ligand was expressed normally. These results suggest that defective expression of the CD40 ligand underlies the failure of isotype switching in this disease.

Adolescent↗
PubMed1991

Hydrops fetalis in the McKusick-Kaufman syndrome: a case report.

McKusick-Kaufman syndrome is an autosomal recessive multiple malformation syndrome characterized by hydrometrocolpos and polydactyly. We report on a patient with McKusick-Kaufman syndrome and severe hydrops. This case illustrates the necessity of genetic evaluations for all patients with unexplained hydrops.

Abnormalities, Multiple↗
PubMed1977

Complement activation in semisolid media: insolubilization of alternative pathway convertases in agar gels with C3 nephritic factor-containing sera.

It was previously shown that when normal human serum and purified properdin or serum containing nephritic factor were allowed to diffuse toward each other in agar, a stainable precipitin line formed only in the presence of an intact alternative pathway. In the present study we have shown that when guinea pig erythrocytes were incorporated in agar and normal human serum was allowed to diffuse toward C3 nephritic factor-containing serum, a line of hemolysis appeared that coincided with the stainable line. The line of hemolysis only formed in the presence of C3, factor B and Mg++, as does the properdin or C3 nephritic factor-induced stainable line. When C2-deficient serum was incorporated in agar with guinea pig erythrocytes and serum samples containing nephritic factor were applied in wells, rings of lysis developed, the areas of which correlated significantly with nephritic factor activity. When partially purified nephritic factor (contaminated only with IgG) or serum containing nephritic factor was subjected to electrophoresis in agar-guinea pig erythrocyte gels and overlaid with normal human serum, bands of lysis developed that required factor B and C3. Lysis of guinea pig erythrocytes in this system appears to be due to insolubilization of alternative pathway convertases with activation of the membrane attack unit C5-C9.

Complement C3↗
PubMed1975

Restoration by purified C3b inactivator of complement-mediated function in vivo in a patient with C3b inactivator deficiency.

In a patient with lifelong increased susceptibility to infection and multiple abnormalities in complement-mediated functions, the infusion of normal plasma had been seen to produce a prolonged partial correction of serum abnormalities. It was subsequently shown that the patient was genetically deficient in the C3b inactivator and that immunochemical depletion of C3b inactivator from normal serum resulted in abnormalities similar to those found in the patient's serum, including alternative pathway C3 activation. Highly purified C3b inactivator was obtained from the euglobulin fraction of normal human serum, sterilized by filtration, and infused intravenously. Partial or complete correction of almost all the known serum abnormalities was obtained. C3b almost disappeared from the serum within 4-5 h, as did Factor C activity. Native C3, C5, and serum hemolytic activity rose to normal or near-normal levels over 4 days and were sustained for another week. Factor B, properdin, opsonic activity, and bactericidal activity reached a level at least two-five times that found before the infusion within 24 h and fell over the next 5 days. These observations prove the primary role of C3b inactivator deficiency in the patient's disease and demonstrate clearly the curcial role in vivo of C3b inactivator in modulating alternative pathway activity.

Blood Proteins↗