An evaluation of semen characteristics in men 45 years of age or older after daily dosing with tadalafil 20mg: results of a multicenter, randomized, double-blind, placebo-controlled, 9-month study.

Objectives: Assess the effects on spermatogenesis of daily tadalafil 20mg over three spermatogenesis cycles in men >or= 45 yr.

Methods: In this double-blind, placebo-controlled, noninferiority study, healthy men (or with mild erectile dysfunction) were randomized to receive tadalafil 20mg (n=125) or placebo (n=128) for 9 mo followed by a 6-mo, treatment-free period. Semen and serum samples were provided at baseline and every 10-12 wk.

Drotrecogin alfa (activated) in patients with severe sepsis presenting with purpura fulminans, meningitis, or meningococcal disease: a retrospective analysis of patients enrolled in recent clinical studies.

Introduction: We report data from adult and pediatric patients with severe sepsis from studies evaluating drotrecogin alfa (activated) (DrotAA) and presenting with purpura fulminans (PF), meningitis (MEN), or meningococcal disease (MD) (PF/MEN/MD). Such conditions may be associated with an increased bleeding risk but occur in a relatively small proportion of patients presenting with severe sepsis; pooling data across clinical trials provides an opportunity for improving the characterization of outcomes.

Methods: A retrospective analysis of placebo-controlled, open-label, and compassionate-use trials was conducted.

Wild squirrel monkey (Saimiri sciureus) "caregiver" calls: Contexts and acoustic structure.

A field study of the vocal behavior of 22 wild adult female squirrel monkeys (Saimiri sciureus) in Parque Nacional del Manu, Peru, found that 21% of vocalizations were "caregiver" calls. Caregiver calls are brief, low frequency calls, often with numerous harmonics, that are addressed by caregivers to their own infants in three contexts: 1) prenurse, signalling the caregiver's location and willingness to nurse; 2) nurse, while nursing; and 3) end nurse, indicating the end of the nursing bout. Three measures (start, end, and peak frequency) of the acoustic structure of the fundamental frequency of the caregiver calls significantly differed across the contexts.

Male residence and association patterns in Costa Rican squirrel monkeys (Saimiri oerstedi).

A model is developed to interpret the evolution of the unusual pattern of male residence and social structure in the Costa Rican squirrel monkey (Saimiri oerstedi). Observations of a wild population document that males 1) maintain close spatial and social associations with other males, especially other males in their birth cohort, but not females and infants; 2) exhibit negligible within-troop male-male aggression, high levels of antipredator vigilance, and frequent predator deterrence; 3) cooperate in aggressive olfactory investigation of females; and 4) maintain residence in their natal troop with their male birth cohort, eventually succeeding to reproductive positions in their natal troop. Less commonly, male age-cohorts leave the troop well past reproductive maturity and usurp the reproductive male cohort in another troop.