Understanding Whole Grain Consumption among Low-Income Older Adults Using the Theory of Planned Behavior.

Older adults have low whole grain (WG) intake. This qualitative study used the Theory of Planned Behavior (TPB) to identify low-income older adults' WG beliefs. A convenience sample of 25 low-income adults 60 years and older were interviewed using questions developed based on TPB constructs: behavioral, normative, and control beliefs. Interviews were audio-recorded, transcribed verbatim, cross-checked for consistency, and analyzed using content analysis. Study results revealed that regarding behavioral beliefs, health benefits, taste, and nutrition were WG advantages and sensory qualities, higher cost, and longer cooking time were disadvantages. Regarding normative beliefs, healthcare professionals and family members approved WG intake and those less informed about WGs disapproved. Regarding control beliefs, availability/accessibility, knowledge of WG benefits, and WG cooking skills facilitated WG intake and age-related changes, WG cost, decreased motivation to cook, and low knowledge (label reading) were barriers. Results provide insights for developing programs to increase older adults' WG intake.

Systems analysis of the transcriptional response of human ileocecal epithelial cells to Clostridium difficile toxins and effects on cell cycle control.

BACKGROUND: Toxins A and B (TcdA and TcdB) are Clostridium difficile's principal virulence factors, yet the pathways by which they lead to inflammation and severe diarrhea remain unclear. Also, the relative role of either toxin during infection and the differences in their effects across cell lines is still poorly understood. To better understand their effects in a susceptible cell line, we analyzed the transciptome-wide gene expression response of human ileocecal epithelial cells (HCT-8) after 2, 6, and 24 hr of toxin exposure. RESULTS: We show that toxins elicit very similar changes in the gene expression of HCT-8 cells, with the TcdB response occurring sooner. The high similarity suggests differences between toxins are due to events beyond transcription of a single cell-type and that their relative potencies during infection may depend on differential effects across cell types within the intestine. We next performed an enrichment analysis to determine biological functions associated with changes in transcription. Differentially expressed genes were associated with response to external stimuli and apoptotic mechanisms and, at 24 hr, were predominately associated with cell-cycle control and DNA replication. To validate our systems approach, we subsequently verified a novel G1/S and known G2/M cell-cycle block and increased apoptosis as predicted from our enrichment analysis. CONCLUSIONS: This study shows a successful example of a workflow deriving novel biological insight from transcriptome-wide gene expression. Importantly, we do not find any significant difference between TcdA and TcdB besides potency or kinetics. The role of each toxin in the inhibition of cell growth and proliferation, an important function of cells in the intestinal epithelium, is characterized.