Christine A. Riedy

Central insulin enhances sensitivity to cholecystokinin

Insulin acts in the brain to reduce food intake and body weight. Cholecystokinin (CCK) reduces meal size when administered peripherally. The purpose of these experiments was to examine their interaction. In Experiment 1, Long-Evans rats were infused with vehicle or insulin at doses from 0.5 to 2.0 mU/day into the third cerebral ventricles. Doses of 1.0 mU/day and higher caused reduced body weight. A dose of 0.5 mU/day was therefore taken to be subthreshold. In Experiment 2, rats receiving 0.5 mU/day of insulin intracerebroventricularly had greater suppression of 30-min meal size in response to intraperitoneal CCK-8 at doses from 0.25 to 8 mg/kg than did rats receiving intracerebroventricular saline. By itself, the insulin had no effect on body weight or meal size. However, a change of sensitivity to CCK by control rats over the course of the experiment clouded the interpretation. A third experiment was therefore conducted in which rats received an acute intracerebroventricular injection of insulin (0.1 mU) or saline 1 h prior to a 30-min meal, and IP CCK-8 (4 mg/kg) or saline immediately prior to the meal. As in Experiment 2, insulin, itself, had no effect on meal size but enhanced the anorexic effect of CCK. These results are consistent with the hypothesis that central insulin acts by altering sensitivity to satiety agents.

The Microbiota of Young Children from Tooth and Tongue Samples

This study determined the frequency with which 38 microbial species were detected in 171 randomly selected children from 6 to 36 months of age. Children were sampled and dental caries measured. Oral samples were assayed by means of a checkerboard DNA probe assay. The detection frequencies from tongue samples in children under 18 mos were: S. mutans 70%, S. sobrinus 72%, P. gingivalis 23%, B. forsythus 11%, and A. actinomycetemcomitans 30%, with similar detection frequencies in children over 18 mos. Thus, S. mutans and the periodontal pathogens, P. gingivalis and B. forsythus, were detected even in the youngest subjects. Species associated with caries included S. mutans (children ages 18-36 mos) and A. israelii (children ages < 18 mos), the latter species possibly reflecting increased plaque in children with caries. Species detection from tooth and tongue samples was highly associated, with most species detected more frequently from tongue than from tooth samples in children under 18 mos, suggesting that the tongue was a potential microbial reservoir.

The evaluation of insulin as a metabolic signal influencing behavior via the brain.

The intent of this paper is to evaluate decreases of food intake and body weight that occur when a peptide is administered to an animal. Using the pancreatic hormone insulin as an example, the case is made that endogenous insulin is normally secreted in response to circulating nutrients as well as in proportion to the degree of adiposity. Hence, its levels in the blood are a reliable indicator of adiposity. A further case is then made demonstrating that insulin is transported through the blood-brain barrier into the brain, where it gains access to neurons containing specific insulin receptors that are important in the control of feeding and metabolism. Finally, experimentally-induced changes of insulin in the brain cause predictable changes of food intake and body weight. Given these observations, the question is then asked: since endogenous insulin, acting within the brain, appears to decrease food intake, can a decrease of food intake caused by exogenous insulin administered into the same area of the brain be ascribed to the same, naturally-occurring response system, or should it be attributed to malaise or a non-specific depression of behavior? Arguments are presented supporting the former position that exogenous insulin, when administered in small quantities directly into the brain, taps into the natural caloric/metabolic system and hence influences food intake and body weight.

Xylitol gummy bear snacks: a school-based randomized clinical trial

BackgroundHabitual consumption of xylitol reduces mutans streptococci (MS) levels but the effect on Lactobacillus spp. is less clear. Reduction is dependent on daily dose and frequency of consumption. For xylitol to be successfully used in prevention programs to reduce MS and prevent caries, effective xylitol delivery methods must be identified. This study examines the response of MS, specifically S. mutans/sobrinus and Lactobacillus spp., levels to xylitol delivered via gummy bears at optimal exposures.MethodsChildren, first to fifth grade (n = 154), from two elementary schools in rural Washington State, USA, were randomized to xylitol 15.6 g/day (X16, n = 53) or 11.7 g/day (X12, n = 49), or maltitol 44.7 g/day (M45, n = 52). Gummy bear snacks were pre-packaged in unit-doses, labeled with ID numbers, and distributed three times/day during school hours. No snacks were sent home. Plaque was sampled at baseline and six weeks and cultured on modified Mitis Salivarius agar for S. mutans/sobrinus and Rogosa SL agar for Lactobacillus spp. enumeration.ResultsThere were no differences in S. mutans/sobrinus and Lactobacillus spp. levels in plaque between the groups at baseline. At six weeks, log10S. mutans/sobrinus levels showed significant reductions for all groups (p = 0.0001): X16 = 1.13 (SD = 1.65); X12 = 0.89 (SD = 1.11); M45 = 0.91 (SD = 1.46). Reductions were not statistically different between groups. Results for Lactobacillus spp. were mixed. Group X16 and M45 showed 0.31 (SD = 2.35), and 0.52 (SD = 2.41) log10 reductions, respectively, while X12 showed a 0.11 (SD = 2.26) log10 increase. These changes were not significant. Post-study discussions with school staff indicated that it is feasible to implement an in-classroom gummy bear snack program. Parents are accepting and children willing to consume gummy bear snacks daily.ConclusionReductions in S. mutans/sobrinus levels were observed after six weeks of gummy bear snack consumption containing xylitol at 11.7 or 15.6 g/day or maltitol at 44.7 g/day divided in three exposures. Lactobacillus spp. levels were essentially unchanged in all groups. These results suggest that a xylitol gummy bear snack may be an alternative to xylitol chewing gum for dental caries prevention. Positive results with high dose maltitol limit the validity of xylitol findings. A larger clinical trial is needed to confirm the xylitol results.Trial registration[ISRCTN63160504]

Integrating Oral and General Health Care

Americans face serious challenges in oral health that result in lost work and school hours and impose heavy costs on the health care system and society. We may be able to address the problem by ending medicines separation between the mouth and the rest of the body.

Changing knowledge and beliefs through an oral health pregnancy message.

OBJECTIVES Pregnancy can be a critical and important period in which to intervene to improve oral health in both the mother and her child. This study examined an online approach for promoting awareness of oral health messages targeted at pregnant women, and whether this type of health messaging impacts oral health knowledge and beliefs. METHODS The study was conducted in three parts: production and pilot testing of a brief commercial, Web site/commercial launch and testing, and dissemination and monitoring of the commercial on a video-sharing site. The brief commercial and pre- and postsurveys were produced and pilot tested among a convenience sample of pregnant women (n = 13). The revised commercial and surveys were launched on a newly created Web site and monitored for activity. After 2 months, the commercial was uploaded to a popular video-sharing Web site. RESULTS Fifty-five individuals completed both the pre- and postsurveys after the Web site was launched. No one responded 100 percent correctly on the presurvey; 77.4 percent responded correctly about dental visits during pregnancy, 66.0 percent about cavity prevention, and 50.9 percent about transmission of bacteria by saliva. Most respondents recalled the correct information on the posttest; 100 percent or close to 100 percent accurately responded about visiting the dentist during pregnancy and preventing cavities, while 79.2 percent responded correctly to the transmission question. CONCLUSION Social media can effectively provide dental health messages during pregnancy. This approach can play an important role in increasing awareness and improving oral health of both mother and child.

An FQHC Research Network in Oral Health: Enhancing the Workforce and Reducing Disparities

Federally Qualified Health Centers (FQHCs) contribute greatly to reducing health disparities by providing care to underserved communities. Yet these safety-net clinics face chronic manpower shortages and turnover. Practice-Based Research Networks aid in translating medical science from bench to clinical practice. These networks have been used to understand and improve health-care delivery and reduce disparities. Initiatives to strengthen lagging translational research in dentistry have begun, but there is no FQHC research network that addresses oral health. This article reviews the potential for, and outlines a model of, an Oral Health FQHC Research Network. It characterizes the needs for an FQHC research network, describes a successful FQHC research-oriented program, and outlines an Oral Health FQHC Research Network conceptual model. It argues that strengthening FQHCs through involvement of their dental staff in clinical research may enhance their jobs, draw staff closer to the community, and strengthen their ability to reduce health disparities.

Treatment fidelity of brief motivational interviewing and health education in a randomized clinical trial to promote dental attendance of low-income mothers and children: Community-Based Intergenerational Oral Health Study “Baby Smiles”

BackgroundFidelity assessments are integral to intervention research but few published trials report these processes in detail. We included plans for fidelity monitoring in the design of a community-based intervention trial.MethodsThe study design was a randomized clinical trial of an intervention provided to low-income women to increase utilization of dental care during pregnancy (mother) or the postpartum (child) period. Group assignment followed a 2 × 2 factorial design in which participants were randomly assigned to receive either brief Motivational Interviewing (MI) or Health Education (HE) during pregnancy (prenatal) and then randomly reassigned to one of these groups for the postpartum intervention. The study setting was four county health departments in rural Oregon State, USA. Counseling was standardized using a step-by-step manual. Counselors were trained to criteria prior to delivering the intervention and fidelity monitoring continued throughout the implementation period based on audio recordings of counselor-participant sessions. The Yale Adherence and Competence Scale (YACS), modified for this study, was used to code the audio recordings of the counselors’ delivery of both the MI and HE interventions. Using Interclass Correlation Coefficients totaling the occurrences of specific MI counseling behaviors, ICC for prenatal was .93, for postpartum the ICC was .75. Participants provided a second source of fidelity data. As a second source of fidelity data, the participants completed the Feedback Questionnaire that included ratings of their satisfaction with the counselors at the completion of the prenatal and post-partum interventions.ResultsCoding indicated counselor adherence to MI protocol and variation among counselors in the use of MI skills in the MI condition. Almost no MI behaviors were found in the HE condition. Differences in the length of time to deliver intervention were found; as expected, the HE intervention took less time. There were no differences between the overall participants’ satisfaction ratings of the HE and MI sessions by individual counselor or overall (p > .05).ConclusionsTrial design, protocol specification, training, and continuous supervision led to a high degree of treatment fidelity for the counseling interventions in this randomized clinical trial and will increase confidence in the interpretation of the trial findings.Trial registrationClinicalTrials.gov: NCT01120041

A surrogate method for comparison analysis of salivary concentrations of Xylitol-containing products

BackgroundXylitol chewing gum has been shown to reduce Streptococcus mutans levels and decay. Two studies examined the presence and time course of salivary xylitol concentrations delivered via xylitol-containing pellet gum and compared them to other xylitol-containing products.MethodsA within-subjects design was used for both studies. Study 1, adults (N = 15) received three xylitol-containing products (pellet gum (2.6 g), gummy bears (2.6 g), and commercially available stick gum (Koolerz, 3.0 g)); Study 2, a second group of adults (N = 15) received three xylitol-containing products (pellet gum, gummy bears, and a 33% xylitol syrup (2.67 g). For both studies subjects consumed one xylitol product per visit with a 7-day washout between each product. A standardized protocol was followed for each product visit. Product order was randomly determined at the initial visit. Saliva samples (0.5 mL to 1.0 mL) were collected at baseline and up to 10 time points (~16 min in length) after product consumption initiated. Concentration of xylitol in saliva samples was analyzed using high-performance liquid chromatography. Area under the curve (AUC) for determining the average xylitol concentration in saliva over the total sampling period was calculated for each product.ResultsIn both studies all three xylitol products (Study 1: pellet gum, gummy bears, and stick gum; Study 2: pellet gum, gummy bears, and syrup) had similar time curves with two xylitol concentration peaks during the sampling period. Study 1 had its highest mean peaks at the 4 min sampling point while Study 2 had its highest mean peaks between 13 to 16 minutes. Salivary xylitol levels returned to baseline at about 18 minutes for all forms tested. Additionally, for both studies the total AUC for the xylitol products were similar compared to the pellet gum (Study 1: pellet gum – 51.3 μg.min/mL, gummy bears – 59.6 μg.min/mL, and stick gum – 46.4 μg.min/mL; Study 2: pellet gum – 63.0 μg.min/mL, gummy bears – 55.9 μg.min/mL, and syrup – 59.0 μg.min/mL).ConclusionThe comparison method demonstrated high reliability and validity. In both studies other xylitol-containing products had time curves and mean xylitol concentration peaks similar to xylitol pellet gum suggesting this test may be a surrogate for longer studies comparing various products.

Recruiting rural dentally-avoidant adolescents into an intervention study.

AIM: To carry out a study designed to test an intervention to increase dental attendance in rural dentally-avoidant adolescents, to identify and recruit eligible adolescents. STUDY DESISN AND METHODS: This study used a cross-sectional design to identify eligible adolescents. A total of 2,762 adolescents (60% of the enrolled students) from junior high and senior high schools in a rural county in Washington State (USA) were given a dental examination with a light and mirror by calibrated dental examiners using WHO criteria. Parents of children with serious dental needs were urged to seek dental care for their adolescent children. They were offered the chance to enrol their child in a study comparing two programs designed to help the adolescent decide whether to seek out dental care. A second group of emancipated adolescents and young adults (aged < 26 years) receiving services at the local college and health department was also screened, and eligible individuals were also offered the chance to enrol. RESULTS AND STSTISTICS: Only 23 (6%) of 357 eligible junior and senior high school adolescents enrolled, compared with 24 (67%) of the 36 eligible emancipated adolescents and young adults. A second follow-up letter was sent to the 85 parents of un-enrolled adolescents with the most severe caries, offering direct assistance in obtaining dental care for their children; only 3 families responded. CONCLUSIONS: This study illustrates the difficulty in engaging adolescents in their oral health and utilization of oral health interventions. The results also suggest that slightly older rural individuals are more interested in and/or able to overcome barriers to seeking out dental care. Alternative strategies are suggested for recruiting avoidant adolescents.