Inhaled dsRNA and rhinovirus evoke neutrophilic exacerbation and lung expression of thymic stromal lymphopoietin in allergic mice with established experimental asthma.

BACKGROUND: Rhinovirus infection or dsRNA stimulation increased thymic stromal lymphopoietin (TSLP), an upstream pro-allergic cytokine, in asthmatic bronchial epithelial cells. We hypothesized that dsRNA challenges superimposed on established experimental allergic asthma constitute a useful exacerbation model. We further hypothesized that TSLP is induced at dsRNA- and rhinoviral infection-induced exacerbations. METHODS: Allergic mice were challenged with OVA followed by three daily intranasal challenges with dsRNA or saline. Bronchoalveolar lavage fluid (BALF) was analysed for total protein, lactate dehydrogenase (LDH), CXCL1/KC, CCL2/MCP-1 and differential cell counts. Lung tissue histology, neutrophils and TSLP, TNF-α, IFN-ß and IFN-λ mRNA were examined. Alternatively, allergen-challenged mice received intranasal rhinovirus-(RV)-1B followed by lung TSLP immunostaining. RESULTS: In mice with allergic airway inflammation, dsRNA challenges caused a significant exacerbation increasing lung tissue inflammation score and tissue neutrophilia. Bronchoalveolar lavage fluid neutrophils, total protein, LDH, CXCL1/KC and CCL2/MCP-1 were also increased (P < 0.01), and so were lung tissue expressions of TNF-α, IFN-λ and TSLP (P < 0.01), but IFN-ß was not increased. TSLP, IFN-λ and LDH were not increased by allergen or dsRNA challenges alone, but increased exclusively at exacerbations. RV1B infection-induced exacerbation also increased lung tissue TSLP (P < 0.05). CONCLUSIONS: dsRNA-induced exacerbation in mice with experimental asthma involved general inflammation, cytokines and interferons, in agreement with previous observations in exacerbating human asthma. Additionally, both dsRNA and RV1B infection increased lung TSLP exclusively at exacerbations. Our data suggest that dsRNA challenges superimposed on allergic inflammation are suited for pharmacological studies of asthma exacerbations including the regulation of lung tissue TSLP, TNF-α, IFN-ß and IFN-λ.

Prevalance and associations of food insecurity in children with diabetes mellitus.

OBJECTIVES: To examine the prevalence of food insecurity in households with a child with insulin-requiring diabetes mellitus (DM), investigate whether food insecurity is associated with poorer DM control, and describe the household characteristics and coping strategies of food-insecure families with a child with DM. STUDY DESIGN: Telephone interviews were conducted with consecutive consenting families over a 16-month period. Food insecurity was assessed through a validated questionnaire; additional questions elicited demographic information and DM management strategies. Charts were reviewed for hemoglobin A1c (HbA1c). Univariate and logistic regression analyses were performed. RESULTS: A total of 183 families were interviewed. Food insecurity was present in 21.9% (95% confidence interval, 15.87%-27.85%), significantly higher than the overall prevalences in Nova Scotia (14.6%) and Canada (9.2%). Food insecurity was associated with higher HbA1c level; however, in multivariate analysis, only child's age and parents' education were independent predictors of HbA1c. Children from food-insecure families had higher rates of hospitalization, for which food security status was the only independent predictor. Common characteristics and coping strategies of food-insecure families were identified. CONCLUSIONS: Food insecurity was more common in families with a child with DM, and the presence of food insecurity was predictive of the child's hospitalization. Risk factors identified in this study should be used to screen for this problem in families with a child with DM.

Food management behaviours in food-insecure, lone mother-led families.

PURPOSE: Little is known about how food is managed in households where food resources are scarce. In this study, the household food management behaviours utilized by food-insecure, lone mother-led families from Atlantic Canada were characterized, and relationships among these behaviours and diet quality were examined. METHODS: Thematic analysis of 24 in-depth interviews from a larger study of mother-led, low-income families was integrated with sociodemographic characteristics, food-insecurity status, and four weekly 24-hour dietary recalls for all household members to yield a family behaviour score (FBS) as a summative measure of food management behaviours, and a healthy plate score (HPS) as a measure of diet quality. RESULTS: Five distinct food management behaviours were identified: authoritative, healthism, sharing, structured, and planning behaviours. An increase in the FBS was associated with a proportional increase in the HPS. Authoritative, healthism, and planning food management behaviours were the strongest predictors of the HPS for all household members (p<0.05). The structured management behaviour was related to the degree of food insecurity. CONCLUSIONS: The FBS and HPS tools hold promise as a way to identify food-insecure families at risk of low diet quality. The next phase of this research will validate the use of these tools in the practice setting.

Developing an interview guide to evaluate practice-based evidence in nutrition: use of the delphi technique.

An interview guide was created for qualitative evaluation of the impact of Practice-based Evidence in Nutrition (PEN) on dietetic practice, and its success as a medium for knowledge translation and transfer (KTT). The Delphi technique was used to bring together a diverse group of experts (n=7) with extensive knowledge in KTT and evidence-based practice (EBP); these experts developed the interview guide content. The technique is an effective means of gathering expert input to inform evaluation tool development, particularly in the absence of accepted evaluation guidelines or pre-existing evaluation tools. Although challenges exist with the Delphi technique, it is an adaptable method that can be modified to meet a variety of needs. During this project, the technique was modified to meet specific needs, including participants' partial anonymity and starting material to reduce the number of required rounds. The resulting interview guide contained open-ended questions focused on respondents' understanding of EBP and PEN, use of PEN by dietitians in other disciplines, perceptions of the quality/usefulness of PEN, and barriers to and facilitators of PEN use.

Achieving healthy body weight in teenagers: evidence-based practice guidelines for community nutrition interventions.

An evidence-based review of research on obesity prevention and treatment in youth was conducted to identify successful elements of community nutrition interventions. Guidelines for dietetic practice appropriate to this age group were synthesized. Following a systematic review of English-language research papers published from 1996 to 2009, 63 interventions met inclusion criteria and were graded according to methodological quality, quantity, consistency, and reproducibility. They also were analyzed for common themes and used to develop guideline statements and a practice algorithm. A national panel of experts in community nutrition, public health, adolescent health, academia, and endocrinology assessed the guidelines and the practice algorithm for validity, acceptability, and applicability. Successful prevention strategies are comprehensive, address social and environmental influences, include nutrition education and physical activity, and use schools as a health promotion delivery venue. Computer- or technology-based and peer-modelling strategies are promising, developmentally appropriate approaches. Effective obesity treatment strategies utilize diet plans and behaviour modification techniques, and involve families in intensive, multidisciplinary interventions. Given the distinct needs of this age group, healthy body weight must be promoted through a comprehensive school-based approach. In summary, obesity prevention and treatment interventions should be comprehensive, multidisciplinary, and developmentally appropriate.

Trans fat information on food labels: consumer use and interpretation.

PURPOSE: Consumers' use and interpretation of trans fat information on food labels were explored. METHODS: Consumers completed an interviewer-administered questionnaire in one of three grocery stores selected purposively to represent geographical location. Data analysis involved examining the relationship of age, gender, grocery shopping habits, household size, and source of nutrition information with awareness, use, and interpretation of trans fat information. RESULTS: Ninety-eight percent (n=239) of participants were aware of trans fat, and most knew of the relationship between trans fat intake and cardiovascular disease. Although the majority of shoppers were aware of the "0 trans fat" nutrition claim on food packages (95%), they were more likely to use the Nutrition Facts panel (60%%) to reduce trans fat intake. Men and consumers under age 40 were least likely to be aware of food label information. While most consumers (75%) correctly interpreted the "0 trans fat" nutrition claim and thought foods with this claim could be healthy choices (64%), only 51% purchased these foods to reduce trans fat intake. CONCLUSIONS: Nutrition professionals should target messages to reduce trans fat intake at men and consumers under age 40. While general knowledge was good, further education is required to help consumers interpret trans fat information.

Beverage consumption in low income, "milk-friendly" families.

PURPOSE: Beverage consumption by poor, lone mother-led, "milk-friendly" families living in Atlantic Canada was characterized over a one-month income cycle. METHODS: Beverage intake and food security status were assessed weekly, using a 24-hour dietary recall and the Cornell-Radimer food insecurity questionnaire. Families were classified as "milk friendly" if total consumption of milk was 720 mL on a single day during the month. Beverage intake was assessed using t-tests, analysis of variance (ANOVA), repeated measures ANOVA with post hoc comparisons, and chi-square analysis. RESULTS: Milk consumption by milk-friendly families (76; total sample, 129) was highest at the time of the month when they had the most money to spend. During all time intervals, mothers consumed the least amount of milk and children aged one to three years consumed the most. Mothers consumed carbonated beverages disproportionately, while children of all ages consumed more fruit juice/drink. Mothers' coffee consumption was profoundly increased when either they or their children were hungry. CONCLUSIONS: The quality of beverage intake by members of low-income households fluctuates in accordance with financial resources available to purchase foods. Mothers' beverage intake is compromised by the degree of food insecurity the family experiences.

Effect of dairy and nondairy snacks on postprandial blood glucose regulation in 9-14-year-old children.

In adults, dairy consumption improves short-term blood glucose regulation. It is unknown if these short-term benefits extend to children of different weight statuses. The objective of this study was to investigate the effect of a dairy and nondairy snack in both normal-weight (NW) and overweight/obese (OW/OB) children on blood glucose regulation and food intake (FI). In a repeated-measures crossover design, 11 NW and 7 OW/OB children (age: 9-14 years), consumed, in random order, a dairy (Greek yogurt, 198.9 g, 171 kcal, 0 g fat, 17 g protein) or nondairy (mini sandwich-type cookies, 37.5 g, 175 kcal, 7.5 g fat, 1.3 g protein) snack containing 25 g of available carbohydrates. Ad libitum FI was measured 120 min after snack consumption. Blood glucose, insulin, C-peptide, and glucagon-like peptide-1 (GLP-1) were measured at 0 min (before the snack), and at 30, 60, 90, and 120 min after snack consumption. Insulin secretion was calculated from deconvolution of C-peptide. Hepatic insulin extraction was calculated as C-peptide divided by insulin. FI did not differ between snacks (P = 0.55). Mean blood glucose was lower (P < 0.001) and insulin higher (P < 0.0001) in the 120 min after consuming the dairy snack. C-Peptide concentrations (P = 0.75) and insulin secretion (P = 0.37) were not different between snacks. The increase in insulin was explained by reduced hepatic insulin extraction (P < 0.01). Consumption of the dairy snack also increased mean GLP-1 concentrations (P < 0.001). In conclusion, consumption of a dairy snack by NW and OW/OB children results in reduced postprandial blood glucose concentrations and elevated circulating insulin compared with a nondairy snack possibly because of delayed hepatic insulin extraction.

Unstable expression and amplification of a transfected oncogene in confluent and subconfluent cells.

NIH 3T3 cells were transfected with a plasmid containing the transforming gene, v-src, from Rous sarcoma virus. One of the transformed cell lines isolated reverted to a flat, nontransformed morphology after cloning through soft agar. This cell line did not express the src gene and could no longer grow in soft agar. When these cells were held at confluence, spontaneous foci appeared which eventually covered the dish. The appearance of foci correlated with an increase in v-src gene expression, ability to grow in soft agar, and tumorigenicity in mice. When these transformed cells were trypsinized and held at subconfluence, both v-src expression and the transformed phenotype were progressively lost. Whereas rearrangement of the transfected gene was not detected, the gene copy number in the transformed cells was markedly increased (greater than 50-fold). Confluence-dependent gene amplification and deamplification have been retained after several cycles of growth alternately at high and low density, in cells recloned through soft agar, and after cells had been maintained continuously at high or low density. The results suggest that, in this cell line, reversible gene amplification plays a central role in expression of the transfected gene.

Diet quality of Atlantic families headed by single mothers.

PURPOSE: As part of a larger study on food insecurity and dietary adequacy of low-income lone mothers and their children in Atlantic Canada, we examined diet quality among household members. METHODS: Network sampling for 'difficult to sample' populations was used to identify mothers living below the poverty line and alone with at least two children under age 14. Trained dietitians administered 24-hour dietary recalls weekly for one month to mothers on the dietary intake of themselves and their children. We calculated Healthy Eating Index category scores for eligible mothers (129) and children (303) using Canada's Food Guide to Healthy Eating and the Nutrition Recommendations for Canadians. RESULTS: Diet quality of low-income lone mothers was poor (35.5%) or in need of improvement (64.5%), with no mother having a good diet. The diet quality of children varied by age, with 22.7% of children aged one to three having a good diet or needing improvement (74.6%), 2.1% of children aged four to eight and no child aged nine to 14 having a good diet, while the diets of about 85% of older children in both age categories needed improvement. CONCLUSIONS: Younger children seem to be protected from poor quality diets in households with limited resources to acquire food.

Compartmentation of phosphorylated precursors of phospholipid biosynthesis in cultured neuroblastoma cells.

The continuous turnover of membrane phospholipids requires a steady supply of biosynthetic precursors. We evaluated the effects of decreasing extracellular Na+ concentration on phospholipid metabolism in cultured neuroblastoma (N1E 115) cells. Incubating cultures with 145 to 0 mM NaCl caused a concentration-dependent inhibition of [32P]phosphate uptake into the water-soluble intracellular pool and incorporation into phospholipid. Phospholipid classes were differentially affected; [32P]phosphate incorporated into phosphati-dylethanolamine (PE) and phosphatidylcholine (PC) was consistently less than into phosphatidylinositol (PI) and phosphatidylserine (PS). This could not be attributed to decreased phospholipid synthesis since under identical conditions, there was no effect on arachidonic acid or ethanolamine incorporation, and choline utilization for PC synthesis was increased. The effect of Na+ was highly specific since reducing phosphate uptake to a similar extent by incubating cultures in a phosphate-deficient medium containing Na+ did not alter the relative distribution of [32P]phosphate in phospholipid. Of several cations tested only Li+ could partially (50%) replace Na+. Incubation in the presence of ouabain or amiloride had no effect on [32P]phosphate incorporation into phospholipid. The differential effects of low Na+ on [32P]phosphate incorporation into PI relative to PC and PE suggests preferential compartmentation of [32P]phosphate into ATP in pools used for phosphatidic acid synthesis and relatively less in ATP pools used for synthesis of phosphocholine and phosphoethanolamine, precursors of PC and PE, respectively. This suggestion of heterogeneous and distinct pools of ATP for phospholipid biosynthesis, and of potential modulation by Na+ ion, has important implications for understanding intracellular regulation of metabolism.

Differences in the metabolism of inositol and phosphoinositides by cultured cells of neuronal and glial origin.

Phosphoinositide and inositol metabolism was compared in glioma (C6), neuroblastoma (N1E-115) and neuroblastoma X glioma hybrid (NG 108-15) cells. All cell lines had similar proportions of phosphatidylinositol (PI), phosphatidylinositol 4-phosphate (PIP), and phosphatidylinositol 4,5-bisphosphate (PIP2). Neuroblastoma and hybrid cells had almost identical phospholipid and phosphoinositide compositions and similar activities for the enzymes metabolizing polyphosphoinositides (PI kinase, PIP phosphatase, PIP kinase, PIP2 phosphatase, PIP2 phosphodiesterase). Glioma cells differed by having greater proportions of ethanolamine plasmalogen and sphingomyelin, lower PIP kinase, 3-5-fold higher PIP phosphatase activity and 10-15-fold greater PIP2 phosphodiesterase activity. Higher PIP phosphatase and PIP2 diesterase activities appear to be characteristic of cells of glial origin, since similar activities were found in primary cultures of astroglia. Glioma cells also metabolize inositol differently. In pulse and pulse-chase experiments, glioma cells transported inositol into a much larger water-soluble intracellular pool and maintained a concentration gradient 30-times greater than neuroblastoma cells. Label in intracellular inositol was less than in phosphoinositides in neuroblastoma and exchanged rapidly with extracellular inositol. In glioma, labeling of intracellular inositol greatly exceeded that of phosphoinositides. As a consequence, radioactivity in prelabeled phosphoinositides could not be effectively chased from glioma cells by excess unlabeled inositol. Such differences between cells of neuronal and glial origin suggest different and possibly supportive roles for these two cell types in maintaining functions regulated through phosphoinositide-linked signalling systems in the central nervous system.

Dietary practices of women diagnosed with environmental sensitivity.

PURPOSE: Food avoidance is central to the treatment of environmental sensitivity (ES), a chronic, often debilitating, multisystem disorder characterized by adverse reactions to non-noxious levels of environmental substances. Because prolonged food avoidance could impact nutritional health, the purpose of this research was to assess adequacy and quality of diets consumed by women diagnosed with ES. METHODS: Twelve women aged 37 to 50 recruited from the Nova Scotia Environmental Health Clinic completed a four-day food record during the spring and summer of 1998. RESULTS: When adequacy of nutrient intake was assessed by comparison to the Estimated Average Requirement, the most limited nutrients in the diet were folate, vitamin B6, vitamin B12, and magnesium. Only one woman exceeded the Adequate Intake for calcium. When diet quality was assessed using the Healthy Eating Index, the majority of women (75%) scored in the "needs improvement" category; intake of milk and dietary variety scored the lowest. Women consumed very few servings from "other foods", defined in the food guide as foods containing mostly sugar and mostly fat. CONCLUSIONS: The results of this study suggest that women diagnosed with ES would benefit from counselling on ways to increase dietary variety, which would lead to improved nutrient intake, and ways to increase calcium intake.

The meaning of food to breast cancer survivors.

Although a definitive relationship between diet and breast cancer remains controversial, many women adopt dietary change after diagnosis. To understand factors motivating dietary change, we explored the meanings that breast cancer survivors attached to food during recovery. Six women who were breast cancer survivors for six to 19 years participated in semi-structured interviews exploring personal meanings attached to food, dietary changes after diagnosis, factors influencing dietary change, and experiences with food in relation to breast cancer. Two distinct phases emerged. These corresponded to active treatment, when women used food to gain control, to cope, for comfort, and for hope, and to post-treatment, when the meanings that women attached to food were shaped by the perception of food's role in breast cancer causation. Women who believed that diet prevents a first diagnosis adopted change to prevent recurrence, while those who did not believe in the relationship between diet and breast cancer adopted change to improve health. In women with breast cancer, food can be an important coping mechanism. Women may benefit from counselling grounded in the meanings they attach to food over the recovery continuum.

Brain mechanisms and the quantitative and qualitative aspects of food intake.

The brain receives a large number of signals from the ingestion of food. They provide the brain with information on both the adequacy of energy ingested and the macronutrient composition of the food. From this information brain feeding control systems are able to respond and direct the animal to make appropriate food choices so that both the quantitative (energy) needs as well as the qualitative (nutrient) needs are met. An understanding of brain mechanisms regulating feeding will only emerge if their dual purposes are recognized.

Food insecurity of low-income lone mothers and their children in Atlantic Canada.

OBJECTIVE: To examine the occurrence and predictors of hunger and food insecurity over the past year and month among low-income mother-led households in Atlantic Canada. METHOD: The Cornell-Radimer Questionnaire to Estimate the Prevalence of Hunger and Food Insecurity was administered weekly for a month, with modifications, to a community sample of 141 lone mothers who took part in a larger dietary intake study. Eligible women included those living alone with at least two children under the age of 14 years in the four Atlantic Provinces and having an annual income less than or equal to Statistics Canada's low-income cut-off. RESULTS: Food insecurity over the past year occurred in 96.5% of households. Child hunger was similar to maternal hunger over the one-month study period (23%), however, it was lower than maternal hunger over the past year. On multiple logistic regression analysis, maternal hunger over the past year was predicted by maternal age over 35 years (p < 0.0005), and Nova Scotia residence (p = 0.03). Child hunger over the past year was also predicted by maternal age over 35 years (p = 0.009). Families from New Brunswick experienced less food insecurity over the past month at both the household (p = 0.01) and maternal levels (p < 0.0005). DISCUSSION: Provincial policies that might contribute to the regular occurrence of food insecurity in these families should be investigated.

Diet and Environmental Illness: Barriers Encountered by Women Sufferers.

Environmental illness is characterized by an ill-defined constellation of signs and symptoms of unknown etiology. It is assumed that exposure to low dose irritants in the environment initiates a chronic and relapsing disorder in susceptible individuals. Although diet is central in the treatment of environmental illness, there is little research to describe how those living with environmental illness view diet and the barriers they encounter. The objective of this work was to look at the perceptions of food and nutrition in a small group of women with a confirmed diagnosis of environmental illness so as to identify common barriers to meeting food needs and to suggest roles for dietitians/nutritionists in assisting those with environmental illness. Eight subjects recruited from a government sponsored Environmental Illness Clinic participated in focus group discussions. Following each session, transcripts were coded and used to generate categories and crosslinks. The most significant barrier encountered by all subjects was the financial cost, be it for treatment, purchasing special foods and nutrient supplements, or misdiagnosis. The next most important variable was time required to complete activities of daily living. Although all participants followed a special diet, this alone was not perceived to be an intrusion. All subjects commented on the social isolation and the way the diagnosis of environmental illness had altered all aspects of their life. Participants identified education and advocacy as the most important areas where dietitians/nutritionists could make a contribution to the health and well-being of this nutritionally vulnerable group.

Adherence to a Very Low Fat Diet for Cardiac Rehabilitation Patients.

Diets encouraging 10% or less fat energy intake have been advocated to prevent progression of coronary artery disease. In this study, a randomized, controlled, repeated measures experimental design was used to determine if reducing fat intake incrementally to an eventual goal of 10% of total energy intake would result in better dietary adherence than would an immediate reduction to 10%. After completing a lifestyle education program and receiving personal dietary counselling, volunteers recruited from a cardiac rehabilitation program (treatment group, n = 4; control group, n = 3) completed a 24-hour recall at two, four, and seven months post-intervention. At these intervals, subjects also spoke with the dietitian to set dietary targets for the incremental reduction group or reinforce them for the immediate reduction group. Neither group achieved the goal of reducing fat intake to 10% of total energy intake, a finding that suggests this may be an unrealistic target. Because both groups consumed about the same percentage of fat energy, there appeared to be no benefit from incremental reduction of fat intake as a strategy to improve dietary adherence.

γδT cells suppress inflammation and disease during rhinovirus-induced asthma exacerbations.

Most asthma exacerbations are triggered by virus infections, the majority being caused by human rhinoviruses (RV). In mouse models, γδT cells have been previously demonstrated to influence allergen-driven airways hyper-reactivity (AHR) and can have antiviral activity, implicating them as prime candidates in the pathogenesis of asthma exacerbations. To explore this, we have used human and mouse models of experimental RV-induced asthma exacerbations to examine γδT-cell responses and determine their role in the immune response and associated airways disease. In humans, airway γδT-cell numbers were increased in asthmatic vs. healthy control subjects during experimental infection. Airway and blood γδT-cell numbers were associated with increased airways obstruction and AHR. Airway γδT-cell number was also positively correlated with bronchoalveolar lavage (BAL) virus load and BAL eosinophils and lymphocytes during RV infection. Consistent with our observations of RV-induced asthma exacerbations in humans, infection of mice with allergic airways inflammation increased lung γδT-cell number and activation. Inhibiting γδT-cell responses using anti-γδTCR (anti-γδT-cell receptor) antibody treatment in the mouse asthma exacerbation model increased AHR and airway T helper type 2 cell recruitment and eosinophilia, providing evidence that γδT cells are negative regulators of airways inflammation and disease in RV-induced asthma exacerbations.

Learning from "Knocks in Life": Food Insecurity among Low-Income Lone Senior Women.

Building on earlier quantitative work where we showed that lone senior households reliant on public pensions in Nova Scotia (NS), Canada lacked the necessary funds for a basic nutritious diet, here we present findings from a qualitative study involving in-depth interviews with eight low-income lone senior women living in an urban area of NS. Using a phenomenological inquiry approach, in-depth interviews were used to explore lone senior women's experiences accessing food with limited financial resources. Drawing upon Bronfenbrenner's Ecological Systems Theory, we explored their perceived ability to access a nutritionally adequate and personally acceptable diet, and the barriers and enablers to do so; as well in light of our previous quantitative research, we explored their perceptions related to adequacy of income, essential expenses, and their strategies to manage personal finances. Seven key themes emerged: world view, income adequacy, transportation, health/health problems, community program use, availability of family and friends, and personal food management strategies. World view exerted the largest influence on seniors' personal perception of food security status. The implications of the findings and policy recommendations to reduce the nutritional health inequities among this vulnerable subset of the senior population are considered.