Vaccines and autism: a tale of shifting hypotheses.

Although child vaccination rates remain high, some parental concern persists that vaccines might cause autism. Three specific hypotheses have been proposed: (1) the combination measles-mumps-rubella vaccine causes autism by damaging the intestinal lining, which allows the entrance of encephalopathic proteins; (2) thimerosal, an ethylmercury-containing preservative in some vaccines, is toxic to the central nervous system; and (3) the simultaneous administration of multiple vaccines overwhelms or weakens the immune system. We will discuss the genesis of each of these theories and review the relevant epidemiological evidence.

Methicillin-resistant Staphylococcus aureus as a cause of extensive retropharyngeal abscess in two infants.

We report 2 cases of extensive methicillin-resistant Staphylococcus aureus (MRSA) retropharyngeal abscesses in young infants. In 1 case, the abscess was associated with a reactive thrombosis of the jugular vein. Based on the existing literature and the rapid emergence of MRSA skin and soft tissue infections, it is possible that similar severe infections will occur with increasing frequency in young infants.

Streptococcus bovis Infection in young Infants.

Background: Sporadic cases of invasive Streptococcus bovis disease have been reported in young infants. However, little is known about the clinical manifestations or the conditions that predispose to S. bovis infection in this population.

Modulating macrophage function with IgG immune complexes.

Macrophages respond to bacterial products by releasing a large array of inflammatory mediators. We demonstrate that, in the presence of IgG immune complexes, macrophages produce high levels of IL-10 and virtually no IL-12, when they are exposed to bacterial products. The production of IL-10 by these cells can dampen innate inflammatory responses to microbial products, such as LPS.