This is a single-center study that will be conducted in two Parts (Part 1 and Part 2). Volunteers may participate in Part 1 or Part 2 of the study but not in both Part 1 and Part 2. Part 1 of the study will evaluate the safety and tolerability of single, oral (by mouth) escalating (increasing) doses of JNJ 28431754 (ranging from 10 mg to 600 mg) or placebo in healthy male volunteers. The pharmacokinetics (PK), how JNJ 28431754 is absorbed, distributed, and removed from the body over time and pharmacodynamics (PD), the effects JNJ-28431754 has on the body, will also be evaluated. Part 2 of the study is a randomized, 2 period crossover study where 8 eligible male volunteers will receive a single oral dose of JNJ 28431754 on 2 occasions (14 days apart) with and without food (ie, a standard meal) to assess the effect of co-administration with food on the PK and PD of JNJ-28431754. In Part 1, at least 48 healthy male volunteers who meet entry criteria will be randomized (assigned by chance) into 6 cohorts (dose groups) and receive a single oral dose of study drug (JNJ-28431754 or placebo); study drug will be assigned to volunteers double-blinded (neither the investigator or the volunteer will know the identity of the assigned treatment). One or more additional cohorts may be added to the study; the additional cohort may test a previously tested dose of JNJ 28431754 as 2 equally divided doses, to be administered 10 hours apart. Each volunteer will participate in one dose group only. Each dose group will evaluate a different dose strength of JNJ-28431754 (10 mg to 600 mg) starting at the lowest dose. Volunteers in each dose group will be required to stay overnight in the clinical research unit (CRU) for 6 nights to receive study drug and to have safety, tolerability, PK, and PD assessments performed. Patients will return to the CRU for a final safety follow-up visit 10 to 14 days after study drug administration. For each volunteer, the total duration of Part 1 of the study will be at least 5 weeks (includes a 3-week screening period). In Part 2 of the study, 8 eligible male volunteers will receive a single oral dose of JNJ 28431754 on 2 occasions (14 days apart) with and without food (ie, a standard meal); JNJ-28431754 will be administered to volunteers as "open-label" treatment (ie, volunteers will know that they are receiving active drug) . Part 2 will begin after sufficient data has been collected from Part 1 to select the dose of JNJ-28431754 for Part 2 of the study (the dose selected will be within the dose range evaluated in Part 1 of the study). Volunteers will be required to stay overnight in the CRU for 5 nights on 2 occasions to receive study drug and to have post dose safety, tolerability, PK, and PD assessments performed. Patients will return to the CRU for a final safety follow-up visit 10 to 14 days after the 2nd single-dose administration of JNJ-38431754. For each volunteer, the total duration of Part 2 of the study will be approximately 7 weeks (includes a 3-week screening period and about a 2-week interval between the 2 single-dose administrations of JNJ 38431754). Volunteers in Part 1 and Part 2 of the study will be monitored for safety during the study by evaluating adverse events reported and results from vital signs measurements, electrocardiograms, physical examinations performed and laboratory tests. Part 1: One dose of JNJ-28431754 (10mg to 600mg) or placebo will be administered after an overnight fast of at least 10 hours (for additional cohorts, previously tested doses will be administered as 2 equally divided doses taken 10 hours apart). Part 2: One dose of JNJ-28431754 will be administered on 2 occasions (14 days apart) after an overnight fast of at least 10 hours with and without a standard meal. All doses of study drug will be administered to patients orally using an oral dispenser.