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Research notes
64 Infectious Diseases Newsletter
rapidly over the first few months of life in sick premature infants than would be expected in term infants. Five infants had undetectable antibody titers when CMV excretion began. Loss of passive acquired antibody and early excretion of virus appear to be associated with symptomatic CMV infection in premature infants born to seropositive mothers. J Pediatr 102:918, 1983 RESEARCH NOTES Measles and Lymphocytes: Greenstein and McFarland examined the in Vitro lymphoproliferative responses to a variety of viruses. They demonstrated that only 5% of individuals responded well to measles virus with a stimulation index greater than 5. Possible explanations include the lack of sensitization, active suppression, or failure in long term stimulation. In order to distinguish among these possibilities, they studied responses of measles virus in 22 immunocompetent individuals during early convalescence from natural measles virus infection. Substantial responses occurred with the stimulation index averaging 7.03, particularly in a small group including individuals with milder cases of the disease. They did find that the level of responsiveness declined over a period of several weeks. Their studies appear to indicate that low responses to measles virus-found in late convalescence represent a lack of prolonged stimulation of lymphocytes which, if measured earlier, will be found to be positive. Infect Immun 40:198, 1983 Chlamydia and Enteric Bacteria: Nurminen and colleagues from Helsinki indicate that there is a strong immunologic cross-reaction between chlamydia and enteric bacteria. The responsible chlamydia antigen appears to be a glycolipid and the cross-reacting antigen of the bacterium is the innermost core of the lipopolysaccharide. They demonstrated this cross-reactivity by use of mutants which were able to elaborate the inner core structure. Interestingly, the chlamydia antigen also had entotoxic properties and was thought to be functionally equivalent to the lipopolysaccharide. The authors suggest that this chlamydial antigen may have a role in the pathogenesis of infections. Science 220:1279, 1983 Antiviral R• of RSV: Hall and her colleagues at Rochester have continued their studies of ribavirin as an antiviral agent. In a randomized double-blind study, infants with lower respiratory
tract disease caused by respiratory synctial virus were given either ribavirin or placebo. Both medications were administered by continuous aerosol for 3 to 6 days. Ribavirin treated infants had significantly greater improvement in clinical symptomatology as measured by a standardized score. They also had better arterial oxygen saturation than the control group. Of interest, viral shedding was decreased in the ribavirin group when compared to the placebo group. There were no significant side effects or toxicity associated with the ribavirin treatment and RSV did not change in sensitivity to the agent despite this continuous exposure. The authors point out the value of effective chemotherapy for RSV in the light of inability to develop an effective vaccine. N Engl J Med 308:1443, 1983 Tetanus Toxoid Skin Testing: Delafuente and colleagues from St. Louis studied the usefulness of tetanus toxoid as a skin test antigen in adults. Tetanus toxoid has been touted as an effective measure of delayed hypersensitivity or cell mediated immunity and, in this study, was contrasted with Candida, mumps, and tuberculin test results. The authors found that Candida and mumps antigens resulted in significantly more positive responses than did tetanus toxoid or tuberculin. They also noticed a decline in tetanus toxoid reactivity as patients aged, suggesting that adequate immunization may wane. They also showed that an immunizing dose of tetanus toxoid could convert a negative skin test to positive in some instances. They question the value of tetanus toxoid in the routine assessment of delayed hypersensitivity but do point out that it may be useful when searching for anergy. With negative responses they suggest that tetanus toxoid immunization can be a prospective test to determine whether an individual is capable of developing delayed hypersensitivity. JAMA 249:3209, 1983 Transfer of Plasmids: Dylan and coworkers in Canada identified a strain of Neisseria meningiditis which was characterized by harboring a 8-1actamase producing plasmid associated with the transfer plasmid previously isolated in penicillinase-producing N. gonorrheae strains. Their data suggests that the acquisition of 8-1actamase production by the meningococcus can occur from antibiotic resistant plasmids of the gonococcus in the genitourinary tract. They cite prior isolation of meningococci from genitourinary sites and the occurrence of double infections with both organisms as circumstantial evidence that plasmid transfer may occur. Lancet i:779, 1983
9 1983 by Elsevier Science Publlghing Co., Inc.
rapidly over the first few months of life in sick premature infants than would be expected in term infants. Five infants had undetectable antibody titers when CMV excretion began. Loss of passive acquired antibody and early excretion of virus appear to be associated with symptomatic CMV infection in premature infants born to seropositive mothers. J Pediatr 102:918, 1983 RESEARCH NOTES Measles and Lymphocytes: Greenstein and McFarland examined the in Vitro lymphoproliferative responses to a variety of viruses. They demonstrated that only 5% of individuals responded well to measles virus with a stimulation index greater than 5. Possible explanations include the lack of sensitization, active suppression, or failure in long term stimulation. In order to distinguish among these possibilities, they studied responses of measles virus in 22 immunocompetent individuals during early convalescence from natural measles virus infection. Substantial responses occurred with the stimulation index averaging 7.03, particularly in a small group including individuals with milder cases of the disease. They did find that the level of responsiveness declined over a period of several weeks. Their studies appear to indicate that low responses to measles virus-found in late convalescence represent a lack of prolonged stimulation of lymphocytes which, if measured earlier, will be found to be positive. Infect Immun 40:198, 1983 Chlamydia and Enteric Bacteria: Nurminen and colleagues from Helsinki indicate that there is a strong immunologic cross-reaction between chlamydia and enteric bacteria. The responsible chlamydia antigen appears to be a glycolipid and the cross-reacting antigen of the bacterium is the innermost core of the lipopolysaccharide. They demonstrated this cross-reactivity by use of mutants which were able to elaborate the inner core structure. Interestingly, the chlamydia antigen also had entotoxic properties and was thought to be functionally equivalent to the lipopolysaccharide. The authors suggest that this chlamydial antigen may have a role in the pathogenesis of infections. Science 220:1279, 1983 Antiviral R• of RSV: Hall and her colleagues at Rochester have continued their studies of ribavirin as an antiviral agent. In a randomized double-blind study, infants with lower respiratory
tract disease caused by respiratory synctial virus were given either ribavirin or placebo. Both medications were administered by continuous aerosol for 3 to 6 days. Ribavirin treated infants had significantly greater improvement in clinical symptomatology as measured by a standardized score. They also had better arterial oxygen saturation than the control group. Of interest, viral shedding was decreased in the ribavirin group when compared to the placebo group. There were no significant side effects or toxicity associated with the ribavirin treatment and RSV did not change in sensitivity to the agent despite this continuous exposure. The authors point out the value of effective chemotherapy for RSV in the light of inability to develop an effective vaccine. N Engl J Med 308:1443, 1983 Tetanus Toxoid Skin Testing: Delafuente and colleagues from St. Louis studied the usefulness of tetanus toxoid as a skin test antigen in adults. Tetanus toxoid has been touted as an effective measure of delayed hypersensitivity or cell mediated immunity and, in this study, was contrasted with Candida, mumps, and tuberculin test results. The authors found that Candida and mumps antigens resulted in significantly more positive responses than did tetanus toxoid or tuberculin. They also noticed a decline in tetanus toxoid reactivity as patients aged, suggesting that adequate immunization may wane. They also showed that an immunizing dose of tetanus toxoid could convert a negative skin test to positive in some instances. They question the value of tetanus toxoid in the routine assessment of delayed hypersensitivity but do point out that it may be useful when searching for anergy. With negative responses they suggest that tetanus toxoid immunization can be a prospective test to determine whether an individual is capable of developing delayed hypersensitivity. JAMA 249:3209, 1983 Transfer of Plasmids: Dylan and coworkers in Canada identified a strain of Neisseria meningiditis which was characterized by harboring a 8-1actamase producing plasmid associated with the transfer plasmid previously isolated in penicillinase-producing N. gonorrheae strains. Their data suggests that the acquisition of 8-1actamase production by the meningococcus can occur from antibiotic resistant plasmids of the gonococcus in the genitourinary tract. They cite prior isolation of meningococci from genitourinary sites and the occurrence of double infections with both organisms as circumstantial evidence that plasmid transfer may occur. Lancet i:779, 1983
9 1983 by Elsevier Science Publlghing Co., Inc.