A case of polymicrobial endocarditis caused by anaerobic organisms in an injection drug user.

Endocarditis is a serious complication of injection drug use most commonly caused by Staphylococcus aureus. We report a case of tricuspid valve polymicrobial bacterial endocarditis in an injection drug user from 3 oral anaerobes: Actinomyces odontolytica, Veillonella species, and Prevotella melaninogenica. The patient was believed to have acquired these organisms from his habit of licking the needle in order to gauge the strength of the cocaine prior to injection.

Interactions between cellular respiration and thermoregulation in the paramecium.

An important adaptation to hypoxia is a regulated reduction in body temperature because it lowers metabolic rate when oxygen supply is limited. Although this beneficial response occurs in organisms ranging from protozoans to mammals, little is known of the cellular mechanisms responsible for the hypoxia-induced reduction in temperature. Using the unicellular protozoan, Paramecium caudatum, we showed that inhibition of oxidative phosphorylation with sodium azide (NaN3) under normoxic conditions mimics the thermoregulatory effects of hypoxia, causing this species to select a lower temperature in a thermal gradient (P < 0.