Dietary and physical activity behaviors of New York City children from different ethnic minority subgroups

OBJECTIVE

To examine racial/ethnic differences in diet and physical activity behaviors in ethnic minority New York City children.

METHODS

Cross-sectional data from a community-based study of 486 6- to 8-year-old children were used. Race/ethnicity was derived using a caregiver's report of child's race and Hispanic ancestry. Dietary intake was obtained by 24-hour diet recalls using the Nutrition Data System for Research. Physical activity was assessed with pedometers and caregiver interviews. We compared diet and activity measures across racial/ethnic subgroups using chi-square and analysis of variance tests. Multivariate analyses adjusted for age, gender, body mass index, and caregiver education (with breastfeeding history and total energy intake included in diet models).

RESULTS

Participants (N = 486) were categorized as Mexican (29.4%), Dominican (8.4%), Puerto Rican (20.6%), other/mixed Hispanic (14.0%), or non-Hispanic black (27.6%). Obesity rates were lower in non-Hispanic blacks (18%) than in Hispanics (31%). Mexicans had the lowest obesity rates among Hispanic subgroups (25%), and Dominicans had the highest (39%). There were differences in mean daily servings of food groups, with Mexicans having healthier diets and Puerto Ricans and non-Hispanic Blacks having less healthy diets. Sedentary time was lower in Mexicans than in other groups in adjusted models. Examination of additional models, including home language, did not show significant differences in the estimates.

CONCLUSION

Diet and activity behaviors varied across racial/ethnic subgroups. Specifically, Mexican children had healthier diets, the least amount of sedentary time, and the lowest rates of obesity among the Hispanic subgroups examined. Targeted interventions in ethnic subgroups may be warranted to address specific behaviors.

The association between parental perception of neighborhood safety and asthma diagnosis in ethnic minority urban children

Low-income populations, minorities, and children living in inner cities have high rates of asthma. Recent studies have emphasized the role of psychosocial stress in development of asthma. Residence in unsafe neighborhoods is one potential source of increased stress. The study objective was to examine the association between parental perception of neighborhood safety and asthma diagnosis among inner city, minority children. Cross-sectional data from a community-based study of 6-8-year-old New York City children were used. Asthma was defined as parental report of physician-diagnosed asthma and at least one asthma-related symptom. Parental perceptions of neighborhood safety were assessed with a questionnaire. Associations between perceived neighborhood safety and asthma were examined using chi-squared tests. Multivariate logistic regression analyses were then performed. Five hundred four children were included with 79% female, 26.5% non-Hispanic Black, and 73.5% Hispanic. Asthma was present in 23.8% of children. There was an inverse association between feeling safe walking in the neighborhood and asthma with 45.7% of parents of asthmatic children reporting they felt safe compared to 60.9% of parents of non-asthmatic children (p = 0.006). Fewer parents of asthmatic children than of non-asthmatic children reported that their neighborhood was safe from crime (21.7% versus 33.9%, p = 0.018). In multivariate analyses adjusting for race/ethnicity, age, gender, socioeconomic status, number of smokers in the home and breastfeeding history, parents reporting feeling unsafe walking in the neighborhood were more likely to have a child diagnosed with asthma (OR = 1.89, 95%CI 1.13-3.14). Psychosocial stressors such as living in unsafe neighborhoods may be associated with asthma diagnosis in urban ethnic minority children. Addressing the increased asthma burden in certain communities may require interventions to decrease urban stressors.

Processing of antibodies bound to B-cell lymphomas and lymphoblastoid cell lines

BACKGROUND

Previous experiments demonstrated that some human B-cell lymphoma cell lines were unusual in that antibodies bound to the cell surface dissociated at high levels. This did not occur with non-B-cell hematologic tumors or with carcinomas. In this study, additional B-cell lymphoma and lymphoblastoid (Epstein-Barr virus-transformed) cell lines were tested.

METHODS

The antibodies selected for most experiments, MA103 and anti-CD45, react with relatively high avidity to the cell surface. Antibodies to CD19, CD20, and CD22 also were tested on certain cell lines. The antibodies were labeled with 125I. After binding to the surface of viable cells, unbound antibody was washed away, and the fate of the bound antibody was investigated for 2-3 days.

RESULTS

Of the eight B-cell lymphomas tested, three had high levels of dissociation, two had low levels of dissociation, and three had intermediate levels of dissociation. The six lymphoblastoid cell lines had only slightly elevated levels of dissociation, relative to non-B cell lines. Sublines of Raji and Ramos cells were identified that varied greatly in the level of antibody dissociation. The level of dissociation from lymphomas was correlated with the tendency of the cell lines to cluster, with single cells displaying less dissociation than clustered cells. However, some exceptions to this correlation were noted. Cell lines such as Ramos, which showed little dissociation of anti-CD20, displayed relatively rapid catabolism of this antibody.

CONCLUSIONS

The level of antibody dissociation as well as the rate of antibody catabolism will affect the results of radioimmunotherapy strongly because these factors affect the time interval for which the cells are in contact with the radioisotope. Different B-cell lines display markedly different levels of dissociation. There is some evidence suggesting that antibody dissociation is high with fresh human tumor cells, but further investigation of this point is required.