Since the lack of transplacental antibody to GBBHS appears to constitute a major determinant of susceptibility to neonatal infection and presently available methods for detecting antibody are cumbersome and time-consuming. a rapid test for antibody would be advantageous for screening populations at risk. Accordingly, we have adapted the streptococcal "long chain reaction" to measure antibody to GBBHS type la in human sera and correlated the results with those previously obtained by mouse protection and bactericidal assays (Clin. Res.. 24:578A. 1976). A mid-log phase inoculum of GBBHS-Ia in Todd-Hewitt broth is incubated with the serum sample for three hours. Smears are made, and the length of 100 streptococcal chains is evaluated microucopically. Hyperimmune anti-GBBHS-Ia rabbit sera and six human sera which protected mice against a LDgo challenge with GBBHS-Ia and opsonized GBBHS-Ia in the in vitro bactericidal assay produced significantly (p<0.001) longer streptococcal chains than heterologous rabbit antisera and 18 human sera which were neither mouse protective nor opsonically active. The "long chain reaction" was demonstrable with a 1:1000 dilution of hyperimmune sera and with 1:32 dilutions of human sera. This simple, sensitive, and rapid method provides a semiquantitative test for antibody to GBBHS.
Newborn infants with "early-onset" disease due to group B beta hemolytic streptococcus were studied over a 40-month period. Clinical presentations included asymptomatic bacteremia, mild transient illness, respiratory distress, meningitis, and overwhelming sepsis. Chronologically, 18 were ill at birth; 10 became ill after a symptom-free period; and four were asymptomatic. Sixty-six percent of the cases weighted less than 2500 grams, and 56% were born to mothers whose amniotic membranes were ruptured for over 20 hours. All 15 of the deaths occurred in low birth weight infants who were criticially ill from birth. A review of 128 consecutive deliveries of infants weighing under 2000 grams revealed 28 cases with prolonged ruptured membranes, and three of these 28 infants developed group B streptococcal infection. The infant of the colonized gravid woman in premature labor or with prolonged ruptured membranes is clearly at risk, and these results suggest that the management of "early-onset" disease should begin prior to delivery.
Rabbit antisera to autologous T and R lvmphohlast cell lines HSB-2 and SR, after reciprocal absorption, were found to detect human T and R lymphocyte antigens (HTLA .'nd HBLA antigens). When tested by indirect imnunofluorescence and C' dependent cytotoxicity, the anti-T cell line serum reacted with T cells but not B cells whereas the anti-B cell line serum reacted with B cells but not T cells. These two antisera also reacted with peripheral blood null cells prepared hy nylon column filtration and E rosette depletion. The sum of the percentages of null cells reacting with each antiserum approximated 100%. Null cell suspensions depleted of cells reacting with one antiserum showed a reciprocal increase in cells reacting with the opposite antiserum.These The suppression of CMI during some acute viral infections, including CMV infections, has been postulated to account for the persistence of these viruses in humans and experimental animals. We have developed an experimental animal model in C3H mice to study CHI during this viral infection. The response of splenic lymphocytes from murine CMV(MCMV) infected mice to phytohemagglutinin(PHA) and lipopolysaccharide(LPS) was suppressed during the acute phase of the infection with maximal suppression on day 4 (25% of control for PHA and 28% of control for LPS) and returned to normal by day 15 The mixed lymphocyte reaction(MLR) of splenic lymphocytes from infected animals was suppressed to 38% of control on day 2, to 9% on day 4, and returned to normal by day 15In contrast, lymphocytes responded to MCMV-infected ayngeneic mo se fibroblasts(MEF) by day 2 incorporating 52.183? Y 9866 CPM of H-thymidine compared to 23.58723909 CPM with uninfected MEF. The response to infected MEF increased to 132,560t 22.739 CPM by day LO These data show that lymphocytes responsive to MCMV antigen are generated at the same time that suppression of the response to mitogens and the MLR is observed. These data suggest that the use of non-specific lymphocyte reactions as an index of CMI may provide misleading information and that the suppressions of such reactions may be a result of the regulation of the specific immune response of the host to the viral infection rather than to direct imnunosuppressive effects of the virus itself. NEONATAL ANDROGEN LEVELS AND ANTIBODY PRODUCTION.705 Jean F. Kenny and Pamela C. Pangburn. Univ. of Pittsburgh Sch. of Med., Dept. of Ped., Pittsburgh. Pa. While data suggest that the effects of sex hormones mainly estrogen(E). may be the basis for sex differences in immunity in later 1ife.the reason for the differences in infancy are obscure. Though serum levels of E in male and female babies arelowand not significant,recent data show marked sex differences in serum concentrations(C)of testosterone(T)with levels in males of 0-3months ranging from 350pg/ml to 2000pg/ml and those in females from 50-100pg/ml. To determine what effects these C of T might have on numbers of anti-bacterial antibody producing cells (APC)spleen cells from outbred mcle Swiss mice injected with 3xl...
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