Despite a significant increase in major obstetric hemorrhage cases, we found improved outcomes and fewer maternal deaths after implementing systemic approaches to improve patient safety. Attention to improving the hospital systems necessary for the care of women at risk for major obstetric hemorrhage is important in the effort to decrease maternal mortality from hemorrhage.

Evidence from various systems suggests that thymus-derived lymphocytes can affect the quality of antibody responses by recognizing various portions of the immunoglobulin receptor of bone-marrow-derived thymus-independent lymphocytes. A model for this process is proposed involving two antigen-specific mature T helper cells, one of which also is specific for immunoglobulin determinants. These two cells act synergistically. Evidence from adoptive secondary antibody responses demonstrates that both cells are antigen-specific T cells and that the immunoglobulin-recognizing T helper cell is absent from experimentally agammaglobulinemic mice. This cell is termed an "immunoglobulin-dependent T cell" because its activation requires the presence of immunoglobulin.

The aim of the project was to determine whether the rate of contaminant blood cultures could be reduced by using a team of dedicated phlebotomists. Comparisons were made between adult patients requiring blood cultures for suspected bacteremia on medical and surgical units before and after the introduction and withdrawal of a dedicated blood culture team. The results showed that a significant reduction in the contaminant blood culture rate was achieved by the blood culture team (P < 0.001; chi(2) test). Therefore, in our experience, the rate of contaminant blood cultures can be reduced in a teaching hospital by using a team of dedicated phlebotomists. Calculations made with our data and those published by others suggest that cost savings from reducing false-positive blood cultures are greater than the cost of the blood culture team.

Antigen preparations derived from Plasmodium falciparum-infected erythrocytes (but not from uninfected erythrocytes) can stimulate the in vitro proliferation of peripheral blood lymphocytes from malaria-sensitized as well as nonsensitized donors. The possibility that the nonspecific responses might be due to a parasite-derived B-cell mitogen has been previously suggested since polyclonal hypergammaglobulinemia is a frequent accompaniment of malaria infection. To test this hypothesis, we investigated the in vitro proliferative responses of purified T-and B-cell populations to malaria antigens. T but not B cells responded to the antigens. The addition of small numbers of T cells restored the ability of purified B cells to respond to lectin mitogens but not to malaria antigens. Falciparum malaria infection was associated with an increase in T-cell but not in B-cell proliferation in vivo, as assessed by the spontaneous tritiated thymidine incorporation of lymphocytes during a brief incubation in vitro. Our observations suggest that extracts of malaria parasites do not contain a B-cell mitogen but are antigenic as well as mitogenic for T cells.

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