Retrospective review of intrauterine device in adolescent and young women.

STUDY OBJECTIVE: To examine our experience with intrauterine device (IUD) use in adolescents and young women. DESIGN: Retrospective descriptive study evaluating outcomes after IUD insertion for patients 21 years or less over an 8-year period. SETTING: Three sites including a Pediatric and Adolescent gynecology private practice, a Title X clinic, and community based, grant funded clinic serving a high risk teen population. PARTICIPANTS: Females from menarche to age 21. MAIN OUTCOMES MEASURED: The probability of IUD retention, differences in IUD retention probabilities between two age groups, and risk factors for IUD removal, expulsion, and infection were evaluated. RESULTS: 233 records showed 50% of the <18-year-old age group and 71.5% of the 18-21-year-old group had their IUD in place at 5 years. Age was found to be a significant factor for removal (P < 0.001), with under 18-year-olds at greater risk of removal/expulsion (hazard ratio (HR) = 2.85). Parity (RR = 5.6 for nulliparous vs multiparous patients, P < 0.001) and prior STI (RR = 5.5, P < 0.001) were significant risk factors for infection. Nulliparous patients were at higher risk of expulsion (P = 0.045), though age was not a statistically significant risk factor. CONCLUSIONS: The rate of continuation was lower in adolescents under 18 compared to 18-21-year-olds, but was still higher than for other hormonal contraceptives. Despite this groups' high risk for STI the IUD did not increase the risk of infection and may offer some degree of protection. IUDs appear to be a safe option in young adolescents (<18 years old) and nulliparous women.

Evolution of altruists and cheaters in near-isogenic populations of Escherichia coli.

Emergence of antibiotic-resistant bacteria threatens the continued efficacy of many critical drugs used to treat serious infections. What if such resistant organisms could also act as altruists and "share" their resistance with sensitive cohorts without any actual genetic exchange? We competed resistant strains that differ solely in their ability to secrete a plasmid-encoded beta-lactamase. Sensitive strains were otherwise isogenic with their resistant counterparts and were either plasmid-free or contained a "Dummy" plasmid of roughly the same size as that of the resistance plasmids. Absent antibiotic selection, plasmid-free sensitive strains outperformed the plasmid-bearing strains. In the presence of ampicillin, the outcome depended on whether the resistant strain secreted its beta-lactamase (Altruist) or retained it (Selfish). In the latter case, only resistant cells survived. When beta-lactamase was secreted, some sensitive cohorts were also provided protection, with the largest fitness increase provided to plasmid-free cells. However, some Altruist strains appeared to be at a disadvantage, as a great deal of their enzyme broke off cells. Thus, additional variables must be considered when designing microbial competition experiments.