Discrepancies in body image perception among fourth-grade public school children from urban, suburban, and rural Maryland

OBJECTIVE: The objective of this study was to determine whether there is an association between body image perception and weight status as measured by the body mass index among a group of fourth graders in Maryland. DESIGN: Cross-sectional data on height, weight, and body image were collected in the classroom. At risk for being overweight and being overweight designations were assigned to participants with body mass index (BMI) percentile values for age and sex of >/=85 to <95 and BMI >/=95, respectively. Students selected a figure (range 1 to 7) to represent their current and ideal images. SUBJECTS: The subjects of this study were 524 fourth-grade public school students (54% girls; 61% white; mean age, 9.2 years) from three geographically distinct regions in Maryland (38.6% urban, 30.7% suburban, 30.7% rural).Statistical analyses chi(2) tests were used to compare weight status with sex, race, geographic location, and body image discrepancy categories. One-way analysis of variance was used to compare BMI and body image scores with sex and race/ethnicity to geographic location. RESULTS: Thirteen percent of students were overweight, and 15% were at risk of overweight. There was no association between weight status and race, body image perception, or geographic location. African Americans chose larger figures than whites and other races to represent their current and ideal images and were most satisfied with their body size. CONCLUSIONS: Perceptions of body image are formed early in life. Dietitians can provide guidance on appropriate weight and body size to children, parents, and school professionals. Dietitians can also use their influence to secure funding for nutrition education programs.     

Linearity of canal-otolith interaction during eccentric rotation in humans

During natural behavior, the head may simultaneously undergo rotation, transduced by the semicircular canals, and translation, transduced by the otolith organs. It has been demonstrated in monkey that the vestibulo-ocular reflexes (VORs) elicited by both endorgans (i.e., the angular and linear VORs, or AVOR and LVOR) sum linearly during combined rotation and translation, but this finding has proven more elusive in humans. To investigate the combined AVOR/LVOR response, six human subjects underwent yaw eccentric rotation at 3 Hz in darkness while displaced from the axis of rotation. Responses to on-center yaw rotation (AVOR alone) and interaural translation (LVOR alone) were also recorded. During eccentric rotation with the subject facing away from the axis of rotation (i.e., nose out), in which a yaw to the right occurs simultaneously with a translation to the right (i.e., translation in phase with rotation), the AVOR and LVOR acted synergistically. Responses were always out of phase with rotation, and became larger in magnitude as vergence increased. For nose-in eccentric rotation, during which translation is out of phase with rotation, the LVOR acted antagonistically to the AVOR. During near viewing, the LVOR often dominated the overall response when eccentricity was sufficiently large, producing eye movements that were in phase with the rotational stimuli. As vergence decreased, the LVOR influence diminished, eventually resulting in responses that were out of phase with rotation at lowest vergence. When the response to pure yaw rotation was vectorially removed from the responses to eccentric rotation, the results proved statistically indistinguishable from the LVOR recorded during interaural translation, suggesting that the ocular response to combined angular and linear motion reflects the linear combination of the AVOR and LVOR.     

Regulation of Osteoclasts by Calcitonin and Amphiphilic Calcitonin Conjugates: Role of Cytosolic Calcium

The peptide hormone calcitonin is a potent inhibitor of osteoclastic resorption, but it is unstable and poorly absorbed following oral administration. Conjugates of salmon calcitonin covalently linked to low-molecular-weight amphiphilic polymers show improved stability and absorption. The purpose of this study was to investigate the biological activity of these conjugates in vitro using rat osteoclasts and HEK-293 cells transfected with the C1a isoform of the calcitonin receptor. Salmon calcitonin or its conjugates (10 pM–10 nM) caused rapid arrest of osteoclast membrane ruffling and subsequent retraction. The same amphiphilic polymer attached to an unrelated protein had no effect on osteoclast morphology or motility. Since calcitonin-induced retraction of osteoclasts is thought to be mediated by Ca²⁺ signaling, we investigated the effects of calcitonin and its conjugates on cytosolic free Ca²⁺ concentration ([Ca²⁺]_i). In HEK-293 cells transfected with the calcitonin receptor, these agents induced transient elevations of [Ca²⁺]_i. However, the rise of [Ca²⁺]_i in HEK-293 cells occurred at concentrations 100–1000-fold higher than those required to elicit osteoclast retraction. To investigate the role of Ca²⁺ in osteoclast retraction, we preloaded cells with BAPTA to buffer changes in [Ca²⁺]_i. BAPTA decreased the initial rate of calcitonin-induced osteoclast retraction, but it did not affect the degree of retraction 2–3 hours following calcitonin, indicating that retraction is mediated primarily by Ca²⁺-independent processes. We conclude that calcitonin conjugates cause osteoclast retraction and [Ca²⁺]_i signaling in a manner similar to that elicited by calcitonin. Thus, orally bioavailable calcitonin conjugates show potential for use as antiresorptive agents.     

A longitudinal perspective on dating violence among adolescent and college-age women

OBJECTIVES: We investigated physical assault in dating relationships and its co-occurrence with sexual assault from high school through college. METHODS: Two classes of university women (n = 1569) completed 5 surveys during their 4 years in college. RESULTS: Women who were physically assaulted as adolescents were at greater risk for revictimization during their freshman year (relative risk = 2.96); each subsequent year, women who have experienced violence remained at greater risk for revictimization than those who have not. Across all years, women who were physically assaulted in any year were significantly more likely to be sexually assaulted that same year. Adolescent victimization was a better predictor of college victimization than was childhood victimization. CONCLUSIONS: There is a need for dating violence prevention/intervention programs in high school and college and for research on factors that reduce revictimization.     

Examining the relationship between impaired host resistance and altered immune function in mice treated with TCDD

Exposure to TCDD suppresses the immune response to numerous antigens, including bacterial and viral pathogens. Although we administer a non-lethal infection with influenza A virus, we often observe significant mortality in TCDD-treated animals. With the goal of identifying which TCDD-induced defects impair host resistance, we conducted a dose response study to examine whether alteration of particular immunological endpoints could be correlated with mortality. C57Bl/6 mice were treated with vehicle control, or 1, 2.5, 5, 7.5 or 10 microg/kg TCDD 1 day prior to intranasal (i.n.) infection with influenza virus. Survival was monitored for 9 days, when remaining mice were sacrificed and multiple endpoints evaluated. Lymphocyte migration to the lung and the production of virus-specific IgG2a, IgG1, and IgG2b antibodies were significantly diminished, even at the lower doses. IgA was enhanced in all groups treated with TCDD. In contrast, T cell expansion in the lymph node, and the production of IFNgamma and IL-12 were relatively resistant to suppression. Treatment with TCDD also enhanced pulmonary neutrophilia in infected mice. These results suggest that decreased antibody production and hyperinflammation may contribute to the death of TCDD-treated mice, and underscore the importance of evaluating numerous endpoints before concluding that a chemical is or is not immunotoxic.     

Impact of socioeconomic deprivation and primary pathology on rate of reversal of Hartmann's procedure

BACKGROUND: Hartmann's procedure is an operation for left-sided colonic pathology where primary anastomosis is considered unsafe. The aim of this study was to assess the impact of socioeconomic deprivation and primary pathology on the rate of reanastomosis. METHODS: All patients who underwent Hartmann's procedure between 1992 and 2000 in our unit were included. The deprivation category (DEPCAT) scores from 1 (affluent) to 7 (most deprived) were calculated. RESULTS: An emergency procedure was performed in 118 of 124 patients. Primary pathology was malignant in 40 and benign in 84 patients. The DEPCAT scores were high (6,7) in 76 and intermediate (3 to 5) in 42 patients. Of the 102 patients surviving the postoperative period, only 23 underwent reversal. The reversal rate was lower in patients with malignancy (P = 0.005) and higher DEPCAT scores. CONCLUSIONS: Primary diagnosis and socioeconomic deprivation adversely influence the rate of reversal of Hartmann's procedure.     

The role of homotypic interactions in the differentiation of B cell precursors

Numerous studies have demonstrated that B lymphopoiesis is dependent upon a stromal cell microenvironment. Many of the stromal cell-derived factors and cell surface interactions that regulate B cell development have been identified; however, little consideration has been paid to the intimate interactions known to occur among B cell precursors themselves in both the fetal liver and marrow microenvironments. In this study we show that homotypic interactions between B cell precursors play an important role in promoting the development of mature B cells. We used an in vitro assay system to demonstrate that the function of stromal cells can be replaced by culturing B cell precursors in proximity. B cell precursors isolated from bcl-2 transgenic mice were used to rule out the possibility that improved survival, hypothesized to result from culturing precursors in proximity, solely accounted for the observed increase in B cell maturation. The putative maturation signal(s) were shown to be dependent upon direct contact between precursors rather than the release of soluble factors from nearby cells. Upon examination of the potential role of several known cell surface proteins, we found that blocking mu heavy chains with monovalent Fab antibody fragments dramatically inhibited maturation, in a stage-specific manner. Together these results suggest that a major function of stromal cells in vivo may be to act as a docking site to promote critical preB-preB homotypic interactions and ensuing signals. Further, the antibody blocking experiments raise the interesting possibility that interactions between B cell precursors themselves may promote and/or regulate preB cell receptor-driven signals.