Bright Start: Description and Main Outcomes From a Group‐Randomized Obesity Prevention Trial in American Indian Children

The aim of the Bright Start study was to develop and test the effectiveness of a school environment intervention, supplemented with family involvement, to reduce excessive weight gain by increasing physical activity and healthy eating practices among kindergarten and first‐grade American Indian children. Bright Start was a group‐randomized, school‐based trial involving 454 children attending 14 schools on the Pine Ridge Reservation in South Dakota. Children were followed from the beginning of their kindergarten year through the end of first grade. Main outcome variables were mean BMI, mean percent body fat, and prevalence of overweight/obese children. The goals of the intervention were to: increase physical activity at school to at least 60 min/day; modify school meals and snacks; and involve families in making behavioral and environmental changes at home. At baseline, 32% of boys and 25% of girls were overweight/obese. Although the intervention was not associated with statistically significant change in mean levels of BMI, BMI‐Z, skinfolds or percentage body fat, the intervention was associated with a statistically significant net decrease of 10% in the prevalence of overweight. Intervention children experienced a 13.4% incidence of overweight, whereas the control children experienced a corresponding incidence of 24.8%; a difference of ?11.4% (P = 0.033). The intervention significantly reduced parent‐reported mean child intakes of sugar‐sweetened beverages, whole milk, and chocolate milk. Changes in duration of school physical activity were not significant. Because obesity is the most daunting health challenge facing American Indian children today, more intervention research is needed to identify effective approaches.     

Effects of two locust control methods on wood-eating termites in arid Australia

Termites are ubiquitous detritivores and are a key influence on soil function and nutrient cycles, particularly in arid and semi-arid ecosystems. Locust control presents a unique hazard to termites and the effective functioning of ecosystems as a consequence of the overlap between pesticide applications and termite populations in grassland and desert landscapes. We monitored the effects of locust control methods using ultra-low-volume (ULV) barrier application of a chemical pesticide, fipronil, and a blanket application of a fungal biopesticide, Metarhizium acridum, on wood-eating termites in arid western New South Wales, Australia. We tested the hypothesis that spray applications decrease termite activity at wood baits using a BACI designed field experiment over 2 years. Our replicated control and treatment sites represented the spatial scale of Australian locust control activities. There was no detectable impact of either locust control treatment on termite activity, bait mass loss or termite community composition measures. Non-significant differences in termite survey measures among sites suggested that climate and environmental conditions were stronger drivers of our termite measures than the single, localized and unreplicated application of pesticides more commonly used in locust control operations in arid Australia. A lack of evidence for an impact of our fipronil or Metarhizium application methods supports their use as low hazard locust control options with minimal large scale and longer-term effects on termites in Australian arid rangelands. Future research would be necessary to determine the probable short-term impacts of treatments on individual termite colonies and the possible impacts on non-wood eating termite species in the arid-zone.     

Personal, behavioral, and environmental risk and protective factors for adolescent overweight

Objective: The objective was to examine a breadth of personal, behavioral, and socio‐environmental factors as potential risk and protective factors of overweight among male and female adolescents. Research Methods and Procedures: A longitudinal study was conducted with an ethnically and socio‐economically diverse sample of 2516 adolescents who completed surveys at both Time 1 (1998 to 1999) and Time 2 (2003 to 2004) of the Project Eating Among Teens (EAT) study. Results: In 1998 to 1999, 335 (25.7%) girls and 282 (26.4%) boys met the age‐adjusted criteria for overweight. During the 5‐year study period, 236 (70.5%) of the overweight girls and 185 (65.7%) of the overweight boys remained overweight and 115 (12.0%) girls and 77 (9.9%) boys originally not overweight became overweight. Although differences by sex were found, a number of personal, behavioral, and socio‐environmental factors were associated with overweight among both male and female adolescents. Body dissatisfaction and weight concerns at Time 1 predicted overweight at Time 2 for both male and female adolescents. Dieting and use of unhealthy weight control behaviors at Time 1 also predicted overweight at Time 2. Greater frequency of breakfast consumption at Time 1 was protective against overweight. Higher levels of weight‐related teasing and parental weight‐related concerns and behaviors at Time 1 were positively associated with Time 2 overweight. Discussion: Body dissatisfaction, weight concerns, use of unhealthy weight control behaviors, weight‐related stigmatization, and parental concern about the child's weight may increase risk for adolescent overweight. Interventions that enhance adolescents’ body satisfaction while providing them with skills to avoid dieting and to engage in more effective weight‐control behaviors should be developed and tested.     

THE DISTRIBUTION OF SPINDLE MICROTUBULES DURING MITOSIS IN CULTURED HUMAN CELLS

WI-38 and HeLa cells in mitosis have been selected from fixed monolayer cultures and serially sectioned for electron microscopy. Sections perpendicular to the spindle axis permit counting of the number of microtubules at each position on the spindle axis and hence the preparation of tubule distribution profiles. Errors intrinsic to this method are discussed. The changes in the tubule distributions from one mitotic stage to another provide evidence concerning the behavior of the spindle tubules during mitosis. The ratio of the number of tubules passing the chromosomes on the metaphase plate to the maximum number in each half spindle is about 1/2. This ratio changes little in early anaphase, and then decreases in late anaphase at about the same time that a zone of increased tubule number develops at the middle of the interzone. The region where the stem bodies form contains about 3/2 the number of tubules seen elsewhere in the interzone. This ratio is almost constant as the mid-body forms in telophase and then increases to 2/1 in early interphase before the final stages of cytokinesis occur.     

Membrane properties of cultured rat sympathetic neurons: Morphological studies of adrenergic and cholinergic differentiation

Dissociated neurons from the newborn rat superior cervical ganglion were grown under conditions which lead to either adrenergic or cholinergic differentiation. Lectins and toxins were used to detect differences in the cell membrane associated with transmitter status, age of the neurons, or location on the neurons. These ligands were made visible in the light or electron microscope by coupling to rhodamine or colloidal gold. The density of binding sites for concanavalin A (Con A), ricin (RCA₆₀), and wheat germ agglutinin (WGA) increased with age in culture on both adrenergic and cholinergic cells. Soybean agglutinin (SBA) binding increased about threefold on adrenergic axons, but failed to increase on neurons induced to become cholinergic by medium conditioned by rat heart cells (CM). The effect of CM on SBA binding paralleled previously described effects of CM on transmitter production; the CM binding pattern developed slowly and was not readily reversible. Mature adrenergic neurons also appeared to bind more WGA than neurons in CM cultures. Tetanus toxin gold binding was uniform, but low, on axons of adrenergic and cholinergic neurons at all ages. In contrast, cholera toxin binding decreased with age on adrenergic axons. Binding sites for SBA and tetanus toxin were found to be less numerous on the cell body surface than on the axonal surface. Thus growth in CM induces fundamental changes in the phenotype of developing sympathetic neurons involving the cell membrane as well as transmitter choice. Differences also appear with maturation and between axonal and somatic cell surface membranes.     

Relative potencies of four reference endotoxin standards as measured by the Limulus amoebocyte lysate and USP rabbit pyrogen tests.

Four commonly used reference endotoxin standards, Escherichia coli O113:H10:K0, E. coli O55:B5, Salmonella abortusequi, and Shigella dysenteriae were compared by the USP rabbit pyrogen and the Limulus amoebocyte lysate tests. By the rabbit pyrogen test, S. abortus equi was identified as the most potent endotoxin, followed closely by E. coli O113:H10:K0 and E. coli O55:B5.     

Coordinate Regulation of Choline Acetyltransferase, Tyrosine Hydroxylase, and Neuropeptide mRNAs by Ciliary Neurotrophic Factor and Leukemia Inhibitory Factor in Cultured Sympathetic Neurons

Abstract: The neurotransmitter phenotype switch that occurs in cultures of rat superior cervical ganglion neurons after treatment with leukemia inhibitory factor or ciliary neurotrophic factor is a useful model permitting investigation of the mechanisms of cytokine-mediated differentiation. Recently the actions of leukemia inhibitory factor and ciliary neurotrophic factor have been linked through their interactions with related receptor complexes. Here we compare the effects of these two cytokines on gene expression in sympathetic neuronal cultures and begin to investigate their mechanisms. We report that, as has been shown for leukemia inhibitory factor, ciliary neurotrophic factor regulates peptides and classical transmitters in these cultures at the mRNA level. In addition, we find that the induction of substance P mRNA by these cytokines is rapid, dependent on protein synthesis, and occurs in 40–50% of superior cervical ganglion neurons in dissociated culture.