A Special Foster Care Program: Reimbursement for parents and consultants

The Special Foster Care Program represents a new community placement option for mentally retarded children. In contrast to traditional models of foster care, it involves a comprehensive five-step system designed to maximize effective care delivery. This article describes the method developed for determining fee schedules and reimbursement rates for participants in the program.This is one of a series of researches carried out in the Ecology of Human Development Program under a grant from the Foundation for Child Development. Robert B. Hampson is Assistant Professor of Psychology, Southern Methodist University. J. B. Tavormina is Assistant Professor of Psychology at the University of Virginia. Rubin Naiman is Director of the Desert Development Center, Las Vegas, Nevada. Jack Kriendler is Operations Manager, Mental Retardation Services, Charlottesville, Virginia.     

Infant exposure to chemicals in breast milk in the United States: what we need to learn from a breast milk monitoring program

The presence of environmental chemicals in breast milk has gained increased attention from regulatory agencies and groups advocating women's and children's health. As the published literature on chemicals in breast milk has grown, there remains a paucity of data on parameters related to infant exposure via breast-feeding, particularly those with a time-dependent nature. This information is necessary for performing exposure assessments without heavy reliance on default assumptions. Although most experts agree that, except in unusual situations, breast-feeding is the preferred nutrition, a better understanding of an infant's level of exposure to environmental chemicals is essential, particularly in the United States where information is sparse. In this paper, we review extant data on two parameters needed to conduct realistic exposure assessments for breast-fed infants: a) levels of chemicals in human milk in the United States (and trends for dioxins/furans); and b) elimination kinetics (depuration) of chemicals from the mother during breast-feeding. The limitations of the existing data restrict our ability to predict infant body burdens of these chemicals from breast-feeding. Although the data indicate a decrease in breast milk dioxin toxic equivalents over time for several countries, the results for the United States are ambiguous. Whereas available information supports the inclusion of depuration when estimating exposures from breast-feeding, the data do not support selection of a specific rate of depuration. A program of breast milk monitoring would serve to provide the information needed to assess infant exposures during breast-feeding and develop scientifically sound information on benefits and risks of breast-feeding in the United States.     

Protective Killed Leptospira borgpetersenii Vaccine Induces Potent Th1 Immunity Comprising Responses by CD4 and γδ T Lymphocytes

Leptospira borgpetersenii serovar hardjo is the most common cause of bovine leptospirosis and also causes zoonotic infections of humans. A protective killed vaccine against serovar hardjo was shown to induce strong antigen-specific proliferative responses by peripheral blood mononuclear cells (PBMC) from vaccinated cattle by 2 months after the first dose of vaccine. This response was absent from nonvaccinated control cattle. The mean response peaked by 2 months after completion of the two-dose vaccination regimen, and substantial proliferation was measured in in vitro cultures throughout the 7 months of the study period. Variations in magnitude of the response occurred among the vaccinated animals, but by 7 months postvaccination there was a substantial antigen-specific response with PBMC from all vaccinated animals. Up to one-third of the PBMC from vaccinated animals produced gamma interferon (IFN-gamma) after 7 days in culture with antigen, as ascertained by flow cytometric analysis, and significant levels of IFN-gamma were measured in culture supernatants by enzyme-linked immunosorbent assay. Two-color immunofluorescence revealed that one-third of the IFN-gamma-producing cells were gammadelta T cells, with the remaining cells being CD4(+) T cells. The significance of this study is the very potent Th1-type immune response induced and sustained following vaccination with a killed bacterial vaccine adjuvanted with aluminum hydroxide and the involvement of gammadelta T cells in the response. Moreover, induction of this Th1-type cellular immune response is associated with the protection afforded by the bovine leptospiral vaccine against L. borgpetersenii serovar hardjo.     

Critical and systematic evaluation of data for estimating human exposures to 2,4-dichlorophenoxyacetic acid (2,4-D) – quality and generalizability

The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been commercially available since the 1940’s. Despite decades of data on 2,4-D in food, air, soil, and water, as well as in humans, the quality the quality of these data has not been comprehensively evaluated. Using selected elements of the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument (temporal variability, avoidance of sample contamination, analyte stability, and urinary methods of matrix adjustment), the quality of 156 publications of environmental- and biomonitoring-based 2,4-D data was examined. Few publications documented steps were taken to avoid sample contamination. Similarly, most studies did not demonstrate the stability of the analyte from sample collection to analysis. Less than half of the biomonitoring publications reported both creatinine-adjusted and unadjusted urine concentrations. The scope and detail of data needed to assess temporal variability and sources of 2,4-D varied widely across the reviewed studies. Exposures to short-lived chemicals such as 2,4-D are impacted by numerous and changing external factors including application practices and formulations. At a minimum, greater transparency in reporting of quality control measures is needed. Perhaps the greatest challenge for the exposure community is the ability to reach consensus on how to address problems specific to short-lived chemical exposures in observational epidemiology investigations. More extensive conversations are needed to advance our understanding of human exposures and enable interpretation of these data to catch up to analytical capabilities. The problems defined in this review remain exquisitely difficult to address for chemicals like 2,4-D, with short and variable environmental and physiological half-lives and with exposures impacted by numerous and changing external factors.     

School Lunch Timing and Children's Physical Activity During Recess: An Exploratory Study

ObjectiveTo examine the relationship between school lunch timing (before vs after recess) on physical activity (PA) during recess and energy balance and food intake at lunch.MethodsA cross-sectional study design was used to examine lunch intake and PA during recess among fourth- and fifth-graders (n = 103) over 5 school days. Lunch and PA were measured using a weighted plate waste technique and accelerometry, respectively.ResultsChildren who received lunch before recess accumulated lower residual energy (ie, energy intake at lunch minus energy expenditure during recess) and consumed a greater proportion of milk servings. No timing effects were observed for other lunch and PA variables.Conclusions and ImplicationsLunch intake and activity during recess are related to lunch timing policy. Findings warrant further examination using experimental and quasi-experimental studies to better understand the impact of timing on health behaviors.     

活体生物萤光成像技术新进展

活体生物萤光成像技术(in vivo biolumines- cence imaging)是近年来发展起来的一项崭新的分子、基因表达的分析检测系统．与传统的检测方法相比具有巨大的优越性,堪称是分子基因检测领域的革命性技术．随着萤光成像设备的进一步完善以及转基因动物的构建开发,在欧美等发达国家活体生物萤光成像技术已被广泛地应用于感染、肿瘤免疫及治疗、自身免疫性疾病、器官移植、基因治疗、药物开发等实验领域．本文就活体生物萤光成像技术的发展和应用作如下综述．     

Developing a broader scientific foundation for river restoration: Columbia River food webs

Well-functioning food webs are fundamental for sustaining rivers as ecosystems and maintaining associated aquatic and terrestrial communities. The current emphasis on restoring habitat structure—without explicitly considering food webs—has been less successful than hoped in terms of enhancing the status of targeted species and often overlooks important constraints on ecologically effective restoration. We identify three priority food web-related issues that potentially impede successful river restoration: uncertainty about habitat carrying capacity, proliferation of chemicals and contaminants, and emergence of hybrid food webs containing a mixture of native and invasive species. Additionally, there is the need to place these food web considerations in a broad temporal and spatial framework by understanding the consequences of altered nutrient, organic matter (energy), water, and thermal sources and flows, reconnecting critical habitats and their food webs, and restoring for changing environments. As an illustration, we discuss how the Columbia River Basin, site of one of the largest aquatic/riparian restoration programs in the United States, would benefit from implementing a food web perspective. A food web perspective for the Columbia River would complement ongoing approaches and enhance the ability to meet the vision and legal obligations of the US Endangered Species Act, the Northwest Power Act (Fish and Wildlife Program), and federal treaties with Northwest Indian Tribes while meeting fundamental needs for improved river management.Recent years have seen substantial expenditures and sustained efforts by government agencies, indigenous people, and nongovernmental organizations to restore rivers and their declining fish stocks. These activities are under increased scrutiny to show that goals and objectives are being met (1, 2). In general, past river restoration has focused on recreating structural attributes (e.g., channel width, complexity) based on the assumption that associated ecological functions will follow (3–6). However, contemporary evidence suggests that ecosystem structure alone does not necessarily reflect how it functions in supporting life. For example, field experiments in the US Pacific Northwest have shown that trophic manipulations (e.g., nutrient additions or salmon carcass introductions) that boost the abundance of potential prey organisms also boost subsequent fish growth (7–10). In contrast, restoration of physical habitats by creating pools or adding structures yields ambiguous evidence that such efforts increase subsequent fish abundance and biomass (11–17). Although it may be premature to conclude from these studies that food availability and species interactions are more limiting to fish than the quality or quantity of the physical habitat, evidence is mounting that many habitat restoration activities are not always as effective in meeting stated goals and objectives as originally anticipated.Nationwide, river restoration practices tend to target the effects of dams, flow manipulation, and channel structure. More than $1 billion/y has been spent since 1990 on river restoration in the United States, with limited evidence of success (1). It has been argued that successful restoration should focus on restoring processes that support ecosystem services and monitoring how processes respond within an adaptive management framework (3, 18, 19). We suggest here that a balance between physical habitat restoration and an understanding of trophic processes supporting biotic communities would improve restoration effectiveness.