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S L Newman

Publications and source records attributed to S L Newman.

82 records · Page 5Linked to original sources
PubMed1979

Recurrent meningococcal meningitis with absence of the sixth component of complement: an evaluation of underlying immunologic mechanisms.

A 51/2-year-old black girl with recurrent meningococcal meningitis and absence of the sixth component of complement (C6) is reported. To explore the pathogenesis of recurrent neisserial infections in C6 deficiency, a detailed analysis of her immune competence was conducted. Her serum had normal chemotactic, opsonic, alternative complement pathway, and specific antibody activity, but lacked complement-mediated bacteriolytic activity. In addition, her C6-deficient serum was indistinguishable from normal serum in a complement-dependent assay of phagocyte bactericidal activity. Absent bacteriolysis remains the only consistent defect associated with recurrent neisserial infections and absence of one of the late-acting complement components.

Blood Bactericidal Activity↗
PubMed1978

Kinetic assessment of alternative complement pathway activity in a hemolytic system. II. Influence of antibody on alternative pathway activation.

By using a kinetic assay, we have examined the role of antibody in the lysis of rabbit erythrocytes (RaRBC) through the alternative complement (C) pathway. Sera from some hypogammaglobulinemic (Hgamma) humans and all agammaglobulinemic chickens tested had subnormal activity in the assay. Heated normal human or chicken sera, but not heated Hgamma sera, restored activity to deficient Hgamma serum and initiated hemolysis in the presence of rabbit serum as C source. Absorption of heated normal human serum with RaRBC, but not with sheep erythrocytes or zymosan, removed its ability to reconstitute deficient Hgamma serum. Normal hemolytic activity could be resotred to Hgamma serum with human IgM, IgG, or colostral IgA, with goat anti-RaRBC IgG, or with an eluate from serum-sensitized RaRBC, but not with myeloma IgA. Restoration of hemolytic activity to Hgamma serum could be achieved in a dose-dependent fashion with the F(ab')2 fragment of IgG. These results suggest that antibody exerts a significant rate-limiting effect on alternative pathway activity in the RaRBC lytic system. This raises the possibility that antibody may be required for efficient alternative pathway activity in vivo and that the pyogenic infections that occur in Hgamma individuals are due to inefficient activation and fixation of C3 through either the classical or alternative pathway.

Agammaglobulinemia↗
PubMed1975

Increased susceptibility to infection in sickle cell disease: defects of opsonization and of splenic function.

Patients with sickle cell disease (SCD) have an increased susceptibility to bacterial infections and die more frequently from infection than any other cause. Their sera do not promote the phagocytosis of pneumococci normally, apparently because of an inability to utilize the alternate pathway for C3 fixation as a means of opsonization. The splenic dysfunction which exists in SCD may result in depressed synthesis of alternate pathway factor(s), as well as in decreased phagocytic clearance of bacteria.

Anemia, Sickle Cell↗