Exposure to estrogen reduces production of immune-related proteins in fish. This suggests that certain compounds, known as endocrine disruptors, may make fish more susceptible to disease.

More than five million people die every year from infectious diseases, despite the availability of numerous antibiotics and vaccines. The discovery of penicillin to treat bacterial infections, along with the development of vaccines for previously incurable virus diseases such as polio and smallpox, achieved great reductions in mortality during the mid-20th century.

Finding an immune system in the social amoeba (Dictyostelium discoideum) is not only surprising but it also may prove a clue as to what is necessary for an organism to become multicellular, said the Baylor College of Medicine researcher who led the research that appears today in the journal Science.

The Bush administration did not give any comment on the US Supreme Court decision, which rejected the contention of India and Mongolia that they are immune to paying taxes on their properties in the United States.