IMMUNE RESPONSES IN VITRO : VI. GENETIC CONTROL OF THE IN VIVO-IN VITRO DISCREPANCIES IN 19S ANTIBODY SYNTHESIS

The finding that the relationship of the in vitro and in vivo responses of different strains of mice is under genetic control indicates that at least two mechanisms must operate under in vivo conditions to control 19S antibody synthesis. One is involved in the termination of 19S antibody synthesis; the other has a regulatory role on the magnitude of the response. In light of these findings, various concepts based on other genetically controlled immune responses and on the limiting dilution technique should be reassessed. Furthermore, the suppressive in vivo mechanism may be an important type of control in the resistance or susceptibility to the establishment or maintainance of neoplasms

Aseptic Meningitis Epidemic during a West Nile Virus Avian Epizootic

While enteroviruses have been the most commonly identified cause of aseptic meningitis in the United States, the role of the emerging, neurotropic West Nile virus (WNV) is not clear. In summer 2001, an aseptic meningitis epidemic occurring in an area of a WNV epizootic in Baltimore, Maryland, was investigated to determine the relative contributions of WNV and enteroviruses. A total of 113 aseptic meningitis cases with onsets from June 1 to September 30, 2001, were identified at six hospitals. WNV immunoglobulin M tests were negative for 69 patients with available specimens; however, 43 (61%) of 70 patients tested enterovirus-positive by viral culture or polymerase chain reaction. Most (76%) of the serotyped enteroviruses were echoviruses 13 and 18. Enteroviruses, including previously rarely detected echoviruses, likely caused most aseptic meningitis cases in this epidemic. No WNV meningitis cases were identified. Even in areas of WNV epizootics, enteroviruses continue to be important causative agents of aseptic meningitis