Perceptions of transitional care needs and experiences in pediatric heart transplant recipients.

Survival following pediatric heart transplantation (HTx) continues to improve. The transition from pediatric to adult care is becoming a pivotal stage in the ongoing medical management of this population. Published data support enhanced outcomes for adolescent patients with increased attention to transitional care. The purpose of this study was to explore the 'transition experience' of adolescent HTx recipients and families. All teens (12-18 years) and parents at a single-center HTx program were invited to participate in semistructured interviews. Qualitative, phenomenological methodology was used to build theoretical knowledge and guided the data collection and analysis. The study population included 14 patients (7 males) with a mean age of 15.7 +/- 1.8 years (11.7-17.8 years) and at a mean of 4.1 +/- 3.3 years post-HTx (0.3-9.2 years) at the time of study participation. Major themes identified included: (i) adolescent disinterest and apathy regarding transition to adult care versus parental anxiety about their child's eventual departure from the pediatric transplant center, (ii) perceived differences in pediatric versus adult care and (iii) identification of strategies described as helpful in facilitating the transition. Understanding the experiences and perceptions of adolescent HTx recipients and their parents is crucial to planning effective transitional care and necessary for evidenced-based practice.

Effect of a triplex-binding ligand on triple helix formation at a site within a natural DNA fragment.

We have used DNase I footprinting to examine the effect of a triplex-binding ligand on the formation of parallel intermolecular DNA triple helices at a mixed sequence target site contained within a natural DNA fragment (tyrT). In the presence of 10 microM ligand (N-[2-(dimethylamino)ethyl]-2-(naphthyl)quinolin-4-ylamine), the binding of CTCTTTTTGCTT (12G) to the sequence GAGAAAAATGAA (generating a complex containing 8 x T x AT, 1 x G x TA and 3 x C+ x GC triplets) was enhanced 3-fold at pH 5.5. When the oligonucleotide CTCTTTTTTCTT (12T) was substituted for 12G (replacing G x TA with T x TA) there was a large reduction in affinity for the target sequence. However, this was stabilized by about 300-fold in the presence of the ligand, requiring a similar concentration to produce a footprint as 12G in the absence of the ligand. When the sequence of the target site was altered to GAGAAAAAAGAA, generating an uninterrupted run of purines [tyrT(46A)], the binding of 12T (generating a complex containing 9 x T x AT, and 3 x C+ x GC triplets) was enhanced 3-fold by 10 microM of the triplex-binding ligand. However, although the binding of 12G to this sequence generating a complex containing a G x AT triplet, was much weaker, this too was stabilized by about 30-fold by the ligand, requiring a similar concentration as the perfect matched oligonucleotide (12T) in the absence of the ligand. A secondary, less stable footprint was also observed in these fragments when using either 12T or 12G, which was evident only in the presence of the triplex-binding ligand. This site, which contained a number of triplet mismatches, appears to be realated to the formation of four or five central T x AT triplets. This reduction in the stringency of oligonucleotide binding by the triplex-binding ligand promotes the formation of complexes at non-targeted regions but may also have the potential for enabling recognition at sites that contain regions where there are no specific triplet matches.