Assessing Barriers to use of the Specific Carbohydrate Diet in Pediatric Inflammatory Bowel Disease: A Qualitative Study.

Because of the high cost and associated toxicities of pharmacotherapy treatment for inflammatory bowel disease (IBD), there has been growing interest in dietary therapy. The objective of this study is to assess barriers to initiating or maintaining the specific carbohydrate diet (SCD) to inform strategies for improving access and adherence to the diet. Methods: We conducted semistructured interviews with parents of 10 children with IBD receiving care at a single academic treatment center. Parents were eligible if their child with IBD was either currently on the SCD, previously on the SCD, or opted not to initiate the SCD. Core questions were developed in conjunction with IBD clinical experts. Interviews were transcribed and analyzed using an inductive approach. Results: Parents of children diagnosed with IBD primarily chose to try the SCD because of concerns about medication safety. Three major barriers to utilizing the SCD emerged: cost, time commitment, and psychosocial impact. Many parents also expressed that following the SCD got easier over time and some parents experienced spillover effects of improved personal health and understanding of nutrition. All parents were strong proponents of the importance of diet in managing IBD and expressed desire for more research into the SCD and other forms of dietary therapy. Conclusions: These findings provide important insight into factors affecting utilization of the SCD in pediatric IBD. Further research is needed to develop interventions or strategies to diminish these barriers and enable more patients to benefit from the SCD.

Arabidopsis PIRL6 Is Essential for Male and Female Gametogenesis and Is Regulated by Alternative Splicing.

Plant intracellular Ras-group leucine-rich repeat (LRR) proteins (PIRLs) are related to Ras-interacting animal LRR proteins that participate in developmental cell signaling. Systematic knockout analysis has implicated some members of the Arabidopsis (Arabidopsis thaliana) PIRL family in pollen development. However, for PIRL6, no bona fide knockout alleles have been recovered, suggesting that it may have an essential function in both male and female gametophytes. To test this hypothesis, we investigated PIRL6 expression and induced knockdown by RNA interference. Knockdown triggered defects in gametogenesis, resulting in abnormal pollen and early developmental arrest in the embryo sac. Consistent with this, PIRL6 was expressed in gametophytes: functional transcripts were detected in wild-type flowers but not in sporocyteless (spl) mutant flowers, which do not produce gametophytes. A genomic PIRL6-GFP fusion construct confirmed expression in both pollen and the embryo sac. Interestingly, PIRL6 is part of a convergent overlapping gene pair, a scenario associated with an increased likelihood of alternative splicing. We detected multiple alternative PIRL6 mRNAs in vegetative organs and spl mutant flowers, tissues that lacked the functionally spliced transcript. cDNA sequencing revealed that all contained intron sequences and premature termination codons. These alternative mRNAs accumulated in the nonsense-mediated decay mutant upf3, indicating that they are normally subjected to degradation. Together, these results demonstrate that PIRL6 is required in both male and female gametogenesis and suggest that sporophytic expression is negatively regulated by unproductive alternative splicing. This posttranscriptional mechanism may function to minimize PIRL6 protein expression in sporophyte tissues while allowing the overlapping adjacent gene to remain widely transcribed.