Postpartum Teenagers' Views on Providing Contraception in School-Based Health Clinics.

BACKGROUND: To determine characteristics of teen pregnancies in southeast Texas and the opinions of postpartum teenagers with regard to having contraceptive services available in high school clinics. METHODS: A cross-sectional study of postpartum teenagers interviewed during their hospital stay. RESULTS: Of 404 postpartum teenagers interviewed, 86% had unplanned pregnancies. Approximately 53% of respondents first had intercourse at less than 16 years of age. Of the 130 teenagers who had used contraception prior to pregnancy, 85% became pregnant because they were unable to visit the clinic to obtain a contraceptive refill or replacement. In multivariate modeling, factors associated with using contraceptives prior to pregnancy included black race (p < .001) and more than 1 previous pregnancy (p < .001). Variables associated with having an unplanned pregnancy included having discussed contraceptives at home or school (p = 0.049). Of the 404 postpartum teenagers surveyed, 223 (82%) were in favor of having contraceptive services offered in high school clinics. CONCLUSIONS: Contraceptive education is not sufficient to prevent teenage pregnancy. Increase in access is critical as teenagers with previous pregnancies were more likely to use contraception, likely due to their interaction with the medical community during the antecedent pregnancy. One possible solution is to bring contraceptive services to the teenagers, by offering them at school based health systems. A majority of teenagers surveyed in this study supported this proposal.

Single turnover kinetics of tryptophan hydroxylase: evidence for a new intermediate in the reaction of the aromatic amino acid hydroxylases.

Tryptophan hydroxylase (TrpH) uses a non-heme mononuclear iron center to catalyze the tetrahydropterin-dependent hydroxylation of tryptophan to 5-hydroxytryptophan. The reactions of the TrpH.Fe(II), TrpH.Fe(II).tryptophan, TrpH.Fe(II).6MePH(4).tryptophan, and TrpH.Fe(II).6MePH(4).phenylalanine complexes with O(2) were monitored by stopped-flow absorbance spectroscopy and rapid quench methods. The second-order rate constant for the oxidation of TrpH.Fe(II) has a value of 104 M(-1) s(-1) irrespective of the presence of tryptophan. Stopped-flow absorbance analyses of the reaction of the TrpH.Fe(II).6MePH(4).tryptophan complex with oxygen are consistent with the initial step being reversible binding of oxygen, followed by the formation with a rate constant of 65 s(-1) of an intermediate I that has maximal absorbance at 420 nm. The rate constant for decay of I, 4.4 s(-1), matches that for formation of the 4a-hydroxypterin product monitored at 248 nm. Chemical-quench analyses show that 5-hydroxytryptophan forms with a rate constant of 1.3 s(-1) and that overall turnover is limited by a subsequent slow step, presumably product release, with a rate constant of 0.2 s(-1). All of the data with tryptophan as substrate can be described by a five-step mechanism. In contrast, with phenylalanine as substrate, the reaction can be described by three steps: a second-order reaction with oxygen to form I, decay of I as tyrosine forms, and slow product release.