Oligosaccharides from human milk block binding and activity of the Escherichia coli heat-stable enterotoxin (STa) in T84 intestinal cells

Enterotoxin-producing Escherichia coli are major causes of pediatric diarrhea in developing countries. The heat-stable enterotoxin of Escherichia coli (STa) causes diarrhea by virtue of its ability to bind to and stimulate intestinal membrane-bound guanylate cyclase, generating cyclic GMP (cGMP). Previous work showed that a fucosylated oligosaccharide fraction of human milk was able to protect suckling mice from the secretory effects of STa, but the mechanism of the protection could not be determined. Oligosaccharide fractions from human milk were tested for their ability to block the biochemical effects of STa in T84 cells, a human colon carcinoma line responsive to the toxin. Total and fucosylated oligosaccharide fractions were found to inhibit STa-stimulated guanylate cyclase activity in T84 cell membranes and cGMP production in intact T84 cells by 60-80%. In addition, the total oligosaccharide fraction and the fucosylated oligosaccharide fraction inhibited 125I-STa binding significantly (17% and 27% inhibition, respectively). These findings demonstrate the protective activity of human milk oligosaccharides against STa in a human-derived cell line and show that the biochemical step blocked by oligosaccharides is STa-mediated stimulation of guanylate cyclase. This represents a novel mechanism by which human milk oligosaccharides protect against diarrhea.     

Family size, infections, and asthma prevalence in New Zealand children.

We conducted a prevalence case-control study to investigate the relation between family composition, infection, and development of asthma at age 7-9 years. Potential cases (399) and controls (398) were selected from the Wellington, NZ, arm of the International Study of Asthma and Allergies in Childhood, a population-based prevalence study. Further screening questions restricted cases to children with a diagnosis of asthma and current medication use (N = 233) and restricted controls to children without a history of wheezing and no diagnosis of asthma (N = 241). After controlling for confounders (including infections, atopy, and socioeconomic status), family size was strongly related to asthma. Having no siblings [prevalence odds ratio (POR) = 2.51; 95% confidence interval (CI) = 1.05-6.01] or one sibling (POR = 1.86; 95% CI = 1.14-3.03) was associated with an increased risk of asthma compared with having more than one sibling. Parent-reported rubeola infection (and possibly other similar viral exanthems) was independently associated with a decreased risk of asthma (POR = 0.48; 95% CI = 0.27-0.83), but reported pertussis infection (POR = 1.57; 95% CI = 0.58-4.24) and day care attendance in the first year of life (POR = 1.81; 95% CI = 0.93-3.51) were not strongly associated with increased risks of asthma.     

Estimated folate intakes: data updated to reflect food fortification, increased bioavailability, and dietary supplement use.

BACKGROUND: There is a critical need to estimate dietary folate intakes for nutrition monitoring and food safety evaluations, but available intake data are seriously limited by several factors. OBJECTIVE: Our objective was to update 2 national food consumption surveys to reflect folate intakes as a result of the recently initiated food fortification program and to correct folate intakes for the apparently higher bioavailability of synthetic folic acid (SFA; ie, folate added to foods or from dietary supplements) than of naturally occurring folate so as to express intakes as dietary folate equivalents. DESIGN: It was not possible to chemically analyze foods, so adjustments were made to food-composition data by using information about food ingredients and characteristics. Total folate intakes were estimated for several sex and age groups by using the modified data coupled with dietary supplement use. RESULTS: Within the limitations of the data, our findings suggested that 67-95% of the population met or surpassed the new estimated average requirement, depending on the sex and age group and survey. Nonetheless, some subgroups had estimated intakes below these standards. Estimated SFA intakes suggested that approximately 15-25% of children aged 1-8 y, depending on the survey, had intakes above the newly established tolerable upper intake level. We estimated that 68-87% of females of childbearing age had SFA intakes below the recommended intake of 400 microgram/d, depending on the age group and survey. CONCLUSION: There is a need to explore ways to improve folate intakes in targeted subgroups, including females of childbearing age, while not putting other population groups at risk of excessive intakes.     

Smokers hospitalized in an urban, public hospital: addiction, stages of change, and self-efficacy.

BACKGROUND: This study characterizes adult smokers on the medicine service of an urban, public hospital, including stage of change, self-efficacy to quit, and nicotine dependence, and explores relationships between perceived and actual smoking-related illness and these three predictive variables. METHODS: Adult patients (n = 154) admitted to the Medicine service of Denver Health Medical Center in October and November 1996 were surveyed using a written questionnaire. RESULTS: The proportion of smokers in this population was 45.7% (95% CI = 42.0%, 49.4%). Adjusted for age and sex, the proportion of smokers in this population was significantly greater than in Colorado (28.8% vs 21.8%, P < 0.001). About half (54.2%) were willing to try free nicotine patches during hospitalization. Among smokers with diseases recognized as smoking-related, 30.4% believed their reason for admission was related to smoking, compared to 20.4% among those with no smoking-related diseases (P = 0.18). Patients who believed their hospitalization was due to smoking had greater intentions (P = 0.001) and self-efficacy (P < 0.001) to quit. CONCLUSIONS: Targeting smokers who perceive that their illness is smoking-related may optimize inpatient smoking interventions.     

Education and training module for a specialist registrar: a move forward in specialist registrar education.

A new post was created in Portsmouth. This produced the opportunity, for a new and innovative approach to the education and training module for the specialist registrar (SpR) training programme. The GP tutor with supervision from the university, designed, implemented and evaluated the module. It took place during the first five months of the SpR contract. The method used was a case study in which the SpR was encouraged to reflect on practice. The learning outcomes were documented initially by the GP tutor and,finally, by the SpR using a logbook based on the dental professional development log. Reflecting on practice enabled the SpR to produce the evidence of her own learning and plan her future learning needs. The project highlights the advantages and problems of reflecting on practice. These issues must be addressed if the conflict between the need to produce the competent doctor and the demands of an educationally sound programme are to be resolved, to create critical thinking and autonomous lifelong, self-directed learners.     

Rapid repeat pregnancy and experiences of interpersonal violence among low-income adolescents

CONTEXT: Rapid repeat pregnancy (RRP) among adolescents, usually defined as pregnancy onset within 12-24 months of the previous pregnancy outcome, has frequently been the target of public health interventions, due to the exacerbation of negative consequences associated with recurrent adolescent pregnancy (and more specifically with childbearing). OBJECTIVE: To examine what, if any, relationship exists between RRP and the experience of interpersonal violence and abuse among low-income adolescents at one semi-urban health center. DESIGN: Case-control study using retrospective chart review. PARTICIPANTS AND SETTING: 100 women aged 13-21 who received prenatal care at one independent nonprofit health center that serves adolescents and their children from June 1994 through June 1996. MAIN OUTCOME MEASURES: Number and timing of pregnancies, occurrence of physical or sexual abuse; other psychosocial risk factors were evaluated. RESULTS: In this population, the experience of any form of physical or sexual violence during the study interval was associated with RRP within 12 months (p = 0.01, OR = 3.46) and 18 months (p = 0.013, OR = 4.29). Other previously reported predictors of RRP, including family stress, financial stress, and other environmental stressors did not reach statistical significance at either 12 months or 18 months in this sample. Of additional note, young women who experienced any form of abuse during the 12-month study interval were substantially more likely to miscarry than were their nonabused peers, and spontaneous abortion was also very strongly associated with RRP (p < 0.00001; OR = 22.6). CONCLUSIONS: The experience of interpersonal violence is correlated with rapid repeat pregnancy among low-income adolescents. This study strongly suggests a need for both extensive screening for partner and family violence among pregnant and postpartum adolescents, and follow-up safety planning support in combination with family planning interventions.