Spherical core-shell alumina support particles for model platinum catalysts.

γ- and δ-alumina are popular catalyst support materials. Using a hydrothermal synthesis method starting from aluminum nitrate and urea in diluted solution, spherical core-shell particles with a uniform particle size of about 1 μm were synthesized. Upon calcination at 1000 °C, the particles adopted a core-shell structure with a γ-alumina core and δ-alumina shell as evidenced by 2D and 3D electron microscopy and 27Al magic angle spinning nuclear magnetic resonance spectroscopy.

Utilization of flax fibers for biomedical applications.

Over the past decades, a large number of animal-derived materials have been introduced for several biomedical applications. Surprisingly, the use of plant-based materials has lagged behind. To study the feasibility of plant-derived biomedical materials, we chose flax (Linum usitatissimum).

Towards eradication of bovine tuberculosis in the European Union.

This paper reviews the developments and progress towards eradication of bovine tuberculosis in the European Union (EU). A historical view of the EU legislation aimed at mainly approximating provisions on intra-community in cattle trade explains the present EU policies. The variety of cattle breeding systems and environmental conditions in the EU leads to different epidemiological situations.

Pyridoxal 5'-phosphate inactivates DNA topoisomerase IB by modifying the lysine general acid.

The present results demonstrate that pyridoxal, pyridoxal 5'-phosphate (PLP) and pyridoxal 5'-diphospho-5'-adenosine (PLP-AMP) inhibit Candida guilliermondii and human DNA topoisomerases I in forming an aldimine with the epsilon-amino group of an active site lysine. PLP acts as a competitive inhibitor of C.guilliermondii topoisomerase I (K(i) = 40 microM) that blocks the cleavable complex formation.

Detection of polychlorinated biphenyls and dioxins in Belgian cattle and estimation of the maximal potential exposure in humans through diets of bovine origin.

The methodology used to detect a polychlorinated biphenyl (PCB)/dioxin contamination in a Belgian cattle population that was not exposed to the PCB/dioxin incident in 1999 is presented. This population is directly or indirectly destined for human consumption. The methodology consisted in the systematic sampling of all calf-fattening stations and groups of cattle destined for export, and in the random sampling of slaughter cattle.

Prevalence of paratuberculosis (Johne's disease) in the Belgian cattle population.

The national bovine paratuberculosis (PTB) seroprevalence (apparent prevalence) in the Belgian cattle population was determined by a serological survey that was conducted from December 1997 to March 1998. In a random sample of herds (N=556, 9.5%), all adult cattle of 24 months of age or older (N=13,317, 0.

Prevalence of bovine herpesvirus-1 in the Belgian cattle population.

The national bovine herpesvirus 1 (BHV-1) seroprevalence (apparent prevalence) in the Belgian cattle population was determined by a serological survey that was conducted from December 1997 to March 1998. In a random sample of herds (N=556), all cattle (N=28478) were tested for the presence of antibodies to glycoprotein B of BHV-1. No differentiation could be made between vaccinated and infected animals, because the exclusive use of marker vaccines was imposed by law only in 1997 by the Belgian Veterinary Authorities.

An experimental infection with a classical swine fever virus in weaner pigs. II. The use of serological data to estimate the day of virus introduction in natural outbreaks.

In a companion paper a logistic regression model of seroprevalence over time was developed on the basis of data obtained during an experimental infection of weaner pigs with classical swine fever (CSF) virus. The model was applied to seroprevalence data from three outbreaks of the 1993-1994 epizootic to test whether the model could predict correctly the day of virus introduction into the herd. It was concluded that the logistic regression model has potential as a tool to estimate in retrospect the day CSF virus was introduced into a pig herd, which in turn may assist in identification of risk factors implicated in the further spread of the disease.

Epidemiological characteristics of an outbreak of classical swine fever in an area of high pig density.

The objective of this study was to analyse an outbreak of classical swine fever under a policy of non-vaccination, intensive surveillance and eradication in an area of high pig density. The virus was found in 52 herds, where some 90,000 pigs were slaughtered. The clinical signs were vague and the reports of suspect herds generally coincided with increased mortality.

The role of T cells in rheumatoid arthritis.

The most striking arguments in favor of a T cell dependent nature of RA are the strong association of the disease with selected class II HLA haplotypes (the "shared epitope" hypothesis) and the fact that, in experimental animal models such as adjuvant arthritis, the disease can be transferred by isolated T cell lines. It is true that T cell activation at the site of inflammation is not excessive. However, there is now unequivocal evidence for focal synthesis of IL-2 and IFN-gamma in the RA synovial membrane and one may realise that a limited but specific T cell activation may be sufficient to induce or perpetuate the immune process.

T cell receptor V beta usage in rheumatoid nodules: marked oligoclonality among IL-2 expanded lymphocytes.

Rheumatoid arthritis is an autoimmune disease which is characterized by chronic polyarthritis and joint destruction as well as by extra-articular manifestations, typically including the appearance of rheumatoid nodules. Although the pathogenesis of the disease is unknown, substantial evidence suggests that it is T cell-mediated. In contrast to experimental models, the disease-mediating T cells in the human situation have never been isolated or identified.

Mg2+, Asp-, and Glu--effects in the processive and distributive DNA relaxation catalyzed by a eukaryotic topoisomerase.

The salt requirement for the catalysis of DNA relaxation carried out by a eukaryotic DNA topoisomerase I from Candida was reexamined with plasmid pBR322 DNA. Two levels of analysis were considered: the initial velocity of the overall reaction and the mode of this reaction (processivity vs distributivity). When looking at the monovalent salts from the first level, the replacement of Cl- by Glu- or Asp- greatly enhanced the salt range over which the enzyme was active.

Lysine degradation in Candida. Characterization and probable role of L-norleucine-leucine, 4-aminobutyrate and delta-aminovalerate:2-oxoglutarate aminotransferases.

Three enzymes partially purified that catalyze respectively the transamination of L-norleucine, 4-aminobutyrate and delta-aminovalerate with alpha-ketoglutarate as aminoacceptor were characterized and isolated from L-lysine adapted cell of Candida guilliermondii var. membranaefaciens. The transaminases have a maximum activity in the pH range of 7.

Candida L-norleucine,leucine:2-oxoglutarate aminotransferase. Purification and properties.

A new enzyme which catalyzes the transamination of L-norleucine (2-aminohexanoic acid) and L-leucine with 2-oxoglutarate was purified to homogeneity from cells of Candida guilliermondii var. membranaefaciens. The relative molecular mass determined by gel filtration was estimated to be close to 100,000.

4-Aminobutyrate:2-oxoglutarate aminotransferase from Candida. Purification and properties.

An enzyme which catalyzes the transamination of 4-aminobutyrate with 2-oxoglutarate was purified 588-fold to homogeneity from Candida guilliermondii var. membranaefaciens, grown with 4-aminobutyrate as sole source of nitrogen. An apparent relative molecular mass of 107,000 was estimated by gel filtration.

DNA topoisomerase activities in concanavalin A-stimulated lymphocytes.

Topoisomerase activities have been measured in nuclear extracts of concanavalin A-stimulated lymphocytes. In parallel with the wave of DNA synthesis, type II topoisomerase activity was considerably increased. After 72 h treatment, this activity was stimulated approx.

The National Evaluation of School Nutrition Programs: program impact on anthropometric measures.

This report describes the anthropometric analysis component of the National Evaluation of School Nutrition Programs. It addresses two research questions: First, is there a relationship between participation in the school nutrition programs and students' height, weight, and triceps fatfold, and, second, are the impacts of program participation on height, weight, and triceps fatfold different for students with different characteristics? The anthropometric analyses suggest that long-term participation in the School Lunch Program has no relationship to height but does have a small relationship to the weight of school-aged children. This is at least partly due to an increase in body fat.

The National Evaluation of School Nutrition Programs: program impact on dietary intake.

This article describes the dietary analysis component of the National Evaluation of School Nutrition Programs. It addresses two research questions: 1) do participants and nonparticipants in the school nutrition programs have different calorie and nutrient intakes for 24 h, breakfast, and/or lunch and 2) if there are differences in the nutritional quality or total quantity of food consumed? Students who participate in the School Lunch Program get more than nonparticipants of almost all nutrients that were examined, both at lunch and during 24 h. The superior lunch and 24-h intakes of Lunch Program participants are due to the higher nutritional quality of the School Lunch compared with lunches that nonparticipants eat.

Quality assurance in ambulatory nutritional care. II. Field testing of criteria.

Quality assurance criteria developed for six target populations of pregnant women and obese infants, children, and adolescents were field tested in 102 ambulatory care settings to determine whether they were relevant, understandable, measurable, behavioral, and achievable. Field testing identified specific problems in ambulatory nutritional care settings related to documentation and feasibility of using patient care records to provide data to assess quality of care and to determine how statements were formulated. Field test results were used to rewrite the criteria.

Quality assurance in ambulatory nutritional care. I. Past, present, and future.

Public health nutritionists have begun to coordinate efforts toward development of national standards for ambulatory nutritional care by writing and field testing criteria for selected target populations of pregnant women, infants, and children. These efforts have identified problems related to the "state of the art" in both quality assurance and nutrition science. This article reviews the literature on quality assurance in nutritional care and summarizes the current efforts culminating in publication of a preliminary guide on quality assurance in ambulatory nutrition care by the U.

Health status and school achievement of children from Head Start and Free School Lunch Programs.

School health records of 332 children through the eighth grade were examined in a retrospective comparative analysis of physical health status and school achievement of children from Head Start and Free School Lunch Programs. The objective was to determine if nutrition early in the lives of children as a part of a comprehensive health and education program such as Head Start produces greater or different benefits for disadvantaged children than nutrition intervention later through free lunches when the child enters school. Cross-sectional longitudinal, and case-study approaches were used in the analysis.