Immunogenicity of the hepatitis A vaccine 20 years after infant immunization.

To determine the duration of immunity provided by the Hepatitis A vaccination (HepA), we evaluated a cohort of participants in Alaska 20 years after being immunized as infants. At recruitment, participants received two doses of inactivated HepA vaccine on one of three schedules. We conducted hepatitis A antibody (anti-HAV) testing for participants at the 20-year time-point. Seventy-five of the original 183 participants (41%) were available for follow-up. The overall anti-HAV geometric mean concentration was 29.9 mIU/mL (95% CI 22.4 mIU/mL, 39.7 mIU/mL) and 50 participants (68%) remained seropositive (titer ≥ 20 mIU/mL). Using a fractional polynomial model, the predicted percent seropositive at 25 years was 55.3%, 49.8% at 30 years and 45.7% at 35 years, suggesting that the percent sero-positive could drop below 50% earlier than previously expected. Further research is necessary to understand if protection continues after seropositivity diminishes or if a HepA booster dose may become necessary.

Tuberculosis makes a comeback.

Tuberculosis (TB) has plagued mankind for many centuries. In the past, the number of people affected with this potentially deadly disease declined, but there has been a recent dramatic increase in TB incidence. This increase is attributed largely to people who are coinfected with TB and HIV and to the development of resistant strains of Mycobacterium tuberculosis during the last decade. The US social infrastructure also has contributed to a rapid rise in TB cases due to adverse socioeconomic factors and an increase in the number of immigrants and people infected with HIV. This article gives a historical overview of TB; discusses its diagnosis, transmission and prevention modalities; and provides a case study about a TB-infected patient who required emergent surgical intervention.

The effect of trans-[Rh(4-ethylpyridine)4Cl2]Cl x 2H2O on nucleic acid and protein syntheses in Escherichia coli.

The effect of the transition metal compound trans-[Rh(4-ethylpyridine)4Cl2]Cl x 2H2O on the syntheses of DNA, RNA, and protein has been investigated for an auxotrophic bacterial strain, Escherichia coli JS-1, incapable of thymidine, uridine, and histidine syntheses. At low concentration (7.4 x 10(-6) M), this rhodium complex interferes with normal cell division and induces the formation of filaments comparable to those observed in the presence of the cis-(NH3)2PtClx antitumour agents. Once the suppressed growth rate of the filamenting cells has been taken into account, the rhodium compound is found not to alter macromolecular synthesis. Again this is consistent with similar observations made for the platinum compounds.