This is a 2-part, single center, double-blind study (neither physician nor participant knows the treatment that the participant receives). Part 1 is designed to evaluate the safety, tolerability, and pharmacokinetics (level of drug in the blood) of a dosing regimen of an investigational drug (JNJ-26528398) prior to its use in Part 2. In Part 1, participants will be assigned by chance to receive either 3 mg/day JNJ-26528398 (6 participants) or placebo (3 participants) for 7 consecutive days while staying in the clinic for 10 days. Placebo is an inactive substance that is compared with a drug to test whether the drug has a real effect. Part 2 is designed to evaluate the anti-inflammatory properties of JNJ-26528398 by measuring markers of inflammation in the blood after intravenous (IV) administration of a substance (endotoxin) which activates the immune system and temporarily causes flu-like symptoms. In Part 2, participants will be assigned by chance to receive up to 3 mg/day JNJ-26528398 (6 participants) or placebo (4 participants) for up to 7 consecutive days while staying in the clinic for 10 days. Endotoxin will be given on the last day of study drug administration. Participants will remain in bed for at least 6 hours after endotoxin administration and will be closely monitored by study personnel.