Positive changes in perceptions and selections of healthful foods by college students after a short-term point-of-selection intervention at a dining hall.

OBJECTIVE: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students' perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. PARTICIPANTS: 104 college students, (age 18-23) completed pre-I and post-I surveys. METHODS: Pre-survey collected at dining hall in April 2007, followed by 3-week intervention then post-survey collected via email. Healthy choice indicators, large signs, table tents, flyers and colorful photographs with "benefit-based messages" promoted targeted foods. Response rate to both surveys was 38%. RESULTS: Significantly more participants reported that healthful choices were clearly identified in the dining hall after the intervention. Over 20% of participants reported becoming more aware of healthful food choices in the dining hall after the intervention. Significant increases in self-reported intake were reported for cottage cheese and low-fat salad dressing, with a trend toward increased consumption of fresh fruit. Seven of the 14 assessed eating behaviors had significant changes in the desired direction. Increased awareness of healthful foods was the top reason for self-reported changes in overall eating behaviors. CONCLUSION: Short-term, multi-faceted, point-of-selection marketing of healthful foods in university dining halls may be beneficial for improving college students' perceptions and selections of targeted healthful foods in the dining hall and may improve overall eating behaviors of college students.

Noninvasive screening for risk factors of type 2 diabetes in young, rural, caucasian children.

School nurses play an important role in identifying students who are at risk for Type 2 diabetes mellitus (T2DM). Few studies have screened Caucasian students, and none have targeted rural, low-income, elementary children. The five noninvasive risk factors used for this study were family history, high body mass index (BMI) for age/sex, racial/ethnic background, hypertension, and acanthosis nigricans. Two thirds of those screened (n = 299) had at least one of the five risk factors for T2DM. Seventeen students (5.6% of those screened) had three or more of the five risk factors and were considered at risk for T2DM. Fifteen percent (n = 43) had hypertension or prehypertension, and 18% (n = 53) were morbidly obese. Hypertension and acanthosis nigricans were significantly associated with being at risk in morbidly obese students. School nurses play an important role as frontline health professionals who are aware that risk factors for T2DM exist in all schools, regardless of students' age, size of community, or ethnic background.

Acetylation of H4 suppresses the repressive effects of the N-termini of histones H3/H4 and facilitates the formation of positively coiled DNA.

We have studied the role of the N-termini of histones H3/H4 in the regulation of the conformational changes that occur in H3/H4 during their deposition on DNA by NAP1 (nucleosome assembly protein 1). Removal of the N-termini extensively increased the right-handed conformation of H3/H4 as assayed by the increased levels of positive coils that were formed on DNA. The osmolytes, TMAO, betaine, sarcosine, alanine, glycine, and proline to varying degrees, facilitated the formation of positive coils. The denaturant, urea (0.6 M), blocked the osmolyte effects, causing a preference of H3/H4 to form negative coils (the left-handed conformation). Acetylated H3/H4 also formed high levels of positive coils, and it is proposed that both the osmolytes and acetylation promote the formation of an alpha-helix in the N-termini. This structural change may ultimately explain a unique feature of transcription through nucleosomes, i.e., that H2A/H2B tends to be more mobile than H3/H4. By using combinations of H3 and H4 that were either acetylated or the N-termini removed, it was also determined that the N-terminus of H4 is primarily responsible for repressing the formation of positive coils. Additional gradient analyses indicate that NAP1 establishes an equilibrium with the H3/H4-DNA complexes. This equilibrium facilitates a histone saturation of the DNA, a unique state that promotes the right-handed conformation. NAP1 persists in the binding of the complexes through interaction with the N-terminus of H3, which may be a mechanism for subsequent remodeling of the nucleosome during transcription and replication.

NAP1 catalyzes the formation of either positive or negative supercoils on DNA on basis of the dimer-tetramer equilibrium of histones H3/H4.

We have studied the tetramer-dimer equilibrium of histones H3/H4 and its effect on DNA supercoiling. Two approaches were found to shift the equilibrium toward dimer. In both instances, when deposited on DNA, the dimers formed positively coiled DNA. The first approach was to modify cysteine 110 of H3 with 5,5'-dithio-bis(2-nitrobenzoic acid (DTNB) and to directly add the histones to DNA at physiological ionic strength. The second approach involved adding an excess of the histone chaperone, nucleosome assembly protein 1 (NAP1) to the H3/H4 prior to deposition on the DNA. It was also observed that when H3/H4 were deposited in the tetrameric state, negatively coiled DNA was formed. The topological state of the DNA prior to deposition was also found to influence the final conformational state of H3/H4. It is proposed that in the tetrameric state, the H3-H3 interface has a left-handed pitch prior to binding DNA. In the dimeric state, the H3-H3 interface is not established until bound to DNA, at which point either the left or right-handed pitch will form on the basis of the initial topology of the DNA. Formaldehyde cross-linking and reversal were applied to identify the histone-histone interactions that facilitate the formation of positive stress. Higher-order interactions between multiple H3/H4 dimers were required to propagate this specific conformation. Changes in the conformational state of H3/H4 were also observed when the histones were bound to DNA prior to treatment with NAP1. It is proposed that these conformational changes in H3/H4 are involved in promoter activation and transcription elongation through nucleosomes.