Environmental risk assessment of genetically engineered herbicide-tolerant Zoysia japonica.

Herbicide-tolerant Zoysia grass (Zoysia japonica Steud.) has been generated previously through Agrobacterium tumefaciens-mediated transformation. The genetically modified (GM) Zoysia grass survived Basta spraying and grew to maturity normally while the wild-type (WT) grass stopped growing and died. GM Zoysia grass will permit more efficient weed control for various turf grass plantings such as home lawns, golf courses, and parks. We examined the environmental/biodiversity risks of herbicide-tolerant GM Zoysia before applying to regulatory agencies for approval for commercial release. The GM and WT Zoysia grass' substantial trait equivalence, ability to cross-pollinate, and gene flow in confined and unconfined test fields were selectively analyzed for environmental/biodiversity effects. No difference between GM and WT Zoysia grass in substantial traits was found. To assess the potential for cross-pollination and gene flow, a non-selective herbicide, Basta, was used. Results showed that unintended cross-pollination with and gene flow from GM Zoysia grass were not detected in neighboring weed species examined, but were observed in WT Zoysia grass (on average, 6% at proximity, 1.2% at a distance of 0.5 m and 0.12% at a radius of 3 m, and 0% at distances over 3 m). On the basis of these initial studies, we conclude that the GM Zoysia grass generated in our laboratory and tested in the Nam Jeju County field does not appear to pose a significant risk when cultivated outside of test fields.

Dynamics of the nucleated polymerization model of prion replication.

The disease process for transmissible spongiform encephalopathies (TSEs), in one way or another, involves the conversion of a predominantly alpha-helical normal host-coded prion protein (PrP(C)) to an abnormally folded (predominantly beta sheet) protease resistant isoform (PrP(Sc)). Several alternative mechanisms have been proposed for this auto-catalytic process. Here the dynamical behavior of one of these models, the nucleated polymerization model, is studied by Monte Carlo discrete-event simulation of the explicit conversion reactions. These simulations demonstrate the characteristic dynamical behavior of this model for prion replication. Using estimates for the reaction rates and concentrations, time courses are estimated for concentration of PrP(Sc), PrP(Sc) aggregates, and PrP(C) as well as size distributions for the aggregates. The implications of these dynamics on protein misfolding cyclic amplification (PMCA) is discussed.

Physical phantom of typical Korean male for radiation protection purpose.

Dose distribution within a human body can be measured using physical anthropomorphic phantoms. In an effort to establish reference Korean physical model, the first Korean physical phantom of average Korean adult male was constructed using computed tomography (CT) images of a healthy volunteer. The body dimension of the subject was close to that of average Korean male. The source images were obtained using fusion positron emission tomography machine at Radiation Health Research Institute in Korea, and ported into rapid prototyping process. The physical phantom was composed of three tissue-equivalent materials: epoxy resin, urethane foam and polyurethane representing bone, lungs and soft tissues, respectively. The densities of the tissue-equivalent materials were close to those recommended by the International Commission on Radiation Units and measurements. To facilitate dose mapping, the phantom was sliced into 2 cm sections. Hole grids for thermoluminescence (TL) dosemeter chips were drilled. To verify the appropriateness of the physical phantom, organ doses of selected organs were measured for reference photon beam, and compared with those computed by tomographic model constructed from the same CT images. Absorbed doses converted from TL relative response showed good agreement within 7% with those calculated.

A new measure of the impact of managed care on healthcare markets.

BACKGROUND: Most studies of managed care impact have used health maintenance organization (HMO) penetration or index of competition as the marker of managed care impact. However, little empirical evidence has been found to support the validity of these or other measures in current use. In addition, as managed care evolves to forms other than HMOs and managed care penetration in large metropolitan areas approaches 100% of commercially insured patients, the utility of the most commonly used measure, HMO penetration, will decrease still further. OBJECTIVES: To provide a preliminary analysis of the use of premiums as a measure of market impact of managed care. STUDY DESIGN: Retrospective analysis (quartile, correlation, multiple-variable linear regression) of publicly available datasets. METHODS: Labor market-adjusted HMO premiums from 3 publicly available sources, for the 56 largest metropolitan areas in the United States, were compared with penetration and index of competition as predictors of the dependent market variable, hospital bed-days per 1000 population. RESULTS: Health maintenance organization premiums in the Federal Employees Health Benefits Program emerged as the best predictor of HMO market impact. Average HMO premiums reported in the Interstudy database and for the Medicare+Choice program also outperformed penetration or index of competition in relating to several commonly available markers of competition such as bed-days per 1000. CONCLUSIONS: Premiums charged by HMOs are a useful measure of the impact of managed care on healthcare markets in large metropolitan areas.

Continence efficacy intervention program for community residing women with stress urinary incontinence in Japan.

Many women in Japan have lived with urinary incontinence (UI). These women are not willing to visit the hospital with their problem of incontinence. Even if the women consent to a hospital visit, continence education is often very limited and patients may immediately stop looking for further treatment. Programs of effective education are needed. The Continence Efficacy Intervention Program (CEIP) was developed for patients and was designed to circumvent many of the obstacles common to stopping exercise. In this study, a randomized trial was conducted to compare the effectiveness of this program to conventional intervention on exercise continuity. This report describes the study design, intervention program, and outcomes. Subjects were 48 women with stress urinary incontinence (SUI): the mean age was 53.5, the mean weight was 56.6 kg, and the average prevalent year was 6.5 years. The CEIP phone interviews improved exercise continuity and urine loss symptom. Findings suggest that this intervention program is effective and readily available to the community-residing women with SUI.

Application of biological monitoring to the quantitative exposure assessment for neuropsychological effect by chronic exposure to organic solvents.

OBJECTIVE: Quantitative exposure assessment became more common as a result of attempts to reduce nondifferential exposure misclassification and to observe a steeper exposure-response relationship. Several exposure variables were compared in a demonstration of the exposure-response relationship between neuropsychological abnormality and long-term exposure to organic solvents in workers at one shipyard. METHOD: Environmental monitoring and biological monitoring were performed to evaluate the exposure of the workers to organic solvents. Cumulative exposure (CE) and lifetime-weighted average exposure variables were developed with both environmental and biological monitoring data. A neuropsychological questionnaire and a function test for confirmation of a disorder or dysfunction in attention, executive function, visuospatial, and constructional abilities, learning and memory, and psychomotor function were performed. RESULTS: The abnormal rate in neuropsychological diagnosis was 9.3% in the exposed group, which was much higher than the 2.1% rate obtained in the nonexposed group (P<0.01). The neuropsychological abnormal rate showed a significant dose-response association with CE created with biological monitoring data. The results also suggest that biological monitoring can provide impressive and effective information for quantitative exposure assessment, even in epidemiology studies.

Direct assessment of the role of NK cells in autoimmune diabetes.

Considerable indirect evidence implicates participation of natural killer cells (NK) in the pathogenesis of diabetes in BB rats. The most convincing evidence derives from studies showing that anti-CD8 antibody effectively prevents both primary disease onset and autoimmune damage to transplanted islets. However, anti-CD8 treatment depletes both NK and cytotoxic T cells (CTL) since both cell types express the CD8 marker. To study directly the role of NK in diabetic BB rats we used MCA 3.2.3, a monoclonal antibody which selectively depletes normal Lewis rats of NK cells but not CTL. A regimen of ip injected antibody achieved rapid reduction of NK cells in diabetic and nondiabetic BB rats by FACS analysis. NK cell activity remained low in rats treated weekly as evidenced by YAC tumor cell killing. We next studied the effect of NK depletion on disease incidence in diabetes-prone BB rats of which about one half are expected to develop diabetes. Onset and incidence of diabetes in 3.2.3-treated and control antibody-treated aged matched litter mates were equal. These studies suggest that NK cells are not necessary for autoimmune islet destruction in spontaneously diabetic BB rats and support a role for CTL in pathogenesis of the disease.

Rethinking population communication.

PIP: This article examines the current renewal of interest in population communication and discusses some major problems in this regard. Population communication here includes both IEC and population information center and clearing-house services (IS). IEC and IS developed independently of each other. The 1st significant rise in interest in population communication occurred during the late 1960s and early 1970s, when the main goal was to create awareness of the availability of contraceptive delivery services. By the mid-1970s, some developing countries experienced a plateauing of contraceptive acceptance, which caused, in turn, integration of population programs with other development programs and emphasis on contraceptive availability. The current renewal of attention in population communication may be attributed to: 1) shifts in the nature, scope, and emphasis of national population programs to include a broader scope and larger emphasis on communication; 2) shifts in the concepts and theories guiding population communication in general, from communication as the linear transfer of messages to communication as a dynamic process of sharing information, from information as a physical entity to information as relative concept, and from the modernization and economic growth perspective of development thinking to the "multiplicity" paradigm; 3) possible signs of convergence between information science and communication science; and 4) the recent development of communication technologies. Some major problems that exist include 1) compartmentalized approaches to population information and communication, 2) a lack of institutional and political support, 3) lower status for information and communication personnel, and 4) a lack of research and evaluation of population communication. These problems must be solved and a more comprehensive perspective of population communication developed to ensure the success of national population programs. An efficient system should be developed to provide the crucial linkages between knowledge-generation and knowledge-utilization systems. Thus, it is necessary to move from a fragmentary approach to a holistic approach in developing a communication system for national population programs. The time is appropriate for linking the components of national population programs for efficiency and success.^ieng

Personal networks and the adoption of family planning in rural Korea.

PIP: This study uses network analysis to assess the effects of community level variables on individual level demographic behavior, isolating communication relationships between individuals and their effects, the justification being abundant documentation of opinion leadership on family planning (FP) adoption. The data employed was part of a pilot project to study effects of total contraceptive availability, instituted in a remote area of Korea. Baseline knowledge/attitude/practice information was included in the data. The final analysis included 5 sets of variables: the 1st were FP adoption indicators, inquiring about knowledge or use of methods and abortion experience. The 2nd variable set contained 6 sociodemographic items, e.g. age, education, marital age, found previously to be most relevant to FP adoption. The 3rd set dealt with sources of FP information, the 4th with FP communication and attitudes on an individual level. The 5th set dealt with numbers of information links with other individuals, direction of the links, and respondents' integrativeness. 6 additional network measures studied division into groups according to constructions of the NEGOPY computer program. A multiple regression analysis then examined variable groups to determine to what extent network measures contributed to the explanation of variance (relative to the other 6 sets of variables) in 6 indicators of family planning adoption. The net contribution of 13 network measures was substantial, with 5 showing the better part of the contribution; the most explanatory are personal network based. Despite a difficulty in isolating causal direction (do women seek adoptors or vice versa) this study does show that close contacts are important in family planning decisions.^ieng