43 research outputs found
Mechanism of Dinitrochlorobenzene-Induced Dermatitis in Mice: Role of Specific Antibodies in Pathogenesis
Dinitrochlorobenzene-induced contact hypersensitivity is widely considered as a cell-mediated rather than antibody-mediated immune response. At present, very little is known about the role of antigen-specific antibodies and B cells in the development of dinitrochlorobenzene-induced hypersensitivity reactions, and this is the subject of the present investigation.Data obtained from multiple lines of experiments unequivocally showed that the formation of dinitrochlorobenzene-specific Abs played an important role in the development of dinitrochlorobenzene-induced contact hypersensitivity. The appearance of dinitrochlorobenzene-induced skin dermatitis matched in timing the appearance of the circulating dinitrochlorobenzene-specific antibodies. Adoptive transfer of sera containing dinitrochlorobenzene-specific antibodies from dinitrochlorobenzene-treated mice elicited a much stronger hypersensitivity reaction than the adoptive transfer of lymphocytes from the same donors. Moreover, dinitrochlorobenzene-induced contact hypersensitivity was strongly suppressed in B cell-deficient mice with no DNCB-specific antibodies. It was also observed that treatment of animals with dinitrochlorobenzene polarized Th cells into Th2 differentiation by increasing the production of Th2 cytokines while decreasing the production of Th1 cytokines.In striking contrast to the long-held belief that dinitrochlorobenzene-induced contact hypersensitivity is a cell-mediated immune response, the results of our present study demonstrated that the production of dinitrochlorobenzene-specific antibodies by activated B cells played an indispensible role in the pathogenesis of dinitrochlorobenzene-induced CHS. These findings may provide new possibilities in the treatment of human contact hypersensitivity conditions
Single scan parameterization of space-variant point spread functions in image space via a printed array: the impact for two PET/CT scanners
Oral Probiotic Control Skin Inflammation by Acting on Both Effector and Regulatory T Cells
Probiotics are believed to alleviate allergic and inflammatory skin disorders, but their impact on pathogenic effector T cells remains poorly documented. Here we show that oral treatment with the probiotic bacteria L. casei (DN-114 001) alone alleviates antigen-specific skin inflammation mediated by either protein-specific CD4+ T cells or hapten-specific CD8+ T cells. In the model of CD8+ T cell-mediated skin inflammation, which reproduces allergic contact dermatitis in human, inhibition of skin inflammation by L. casei is not due to impaired priming of hapten-specific IFNγ-producing cytolytic CD8+ effector T cells. Alternatively, L. casei treatment reduces the recruitment of CD8+ effector T cells into the skin during the elicitation (i.e. symptomatic) phase of CHS. Inhibition of skin inflammation by L. casei requires MHC class II-restricted CD4+ T cells but not CD1d-restricted NK-T cells. L casei treatment enhanced the frequency of FoxP3+ Treg in the skin and increased the production of IL-10 by CD4+CD25+ regulatory T cells in skin draining lymph nodes of hapten-sensitized mice. These data demonstrate that orally administered L. casei (DN-114 001) efficiently alleviate T cell-mediated skin inflammation without causing immune suppression, via mechanisms that include control of CD8+ effector T cells and involve regulatory CD4+ T cells. L. casei (DN-114 001) may thus represent a probiotic of potential interest for immunomodulation of T cell-mediated allergic skin diseases in human
Women, common property resources and livestock husbandry in Thai villages
In many Asian countries, women play a significant but varying role in the management of livestock and the use of common resources plays an important role in animal husbandry, and can affect the health of some types of livestock. This paper concentrates on village livestock in Thailand and makes use of survey data as well as national statistics. It first of all outlines the nature and development of livestock industries in Thailand. It then considers the role which women play in the village livestock economy in relation to cattle and buffalo, particularly dairying, and in the keeping of poultry and pigs. The extent to which women are involved in maintaining the health of livestock is considered. Both village bovines and poultry utilise common property resources to a considerable extent in Thailand. This has implications for the economics and productivity of keeping village livestock, the healthiness of such livestock and the spread of livestock diseases
Its economic evolution and problems raised by land rights and cattle diseases
Changes in the economic, demographic and political characteristics of Thailand have had a strong impact on the traditional nature of Thailand's agriculture and livestock industries over the past few decades. This paper outlines the development of the Thai dairy industry and discusses economic factors, including government policies, influencing its development. Land rights have affected its development, e.g. the availability of credit to dairy farmers. In addition, the small size of Thai farms and lack of a ready market in land have resulted in small herd sizes. Furthermore, the extensive use of common property resources has implications for resource management and sustainable agricultural development in Thailand. A number of environmental issues are considered, associated with raising dairy cattle and other livestock in Thailand. The growth of the Thai industry highlights the urgency of cattle disease control, especially the control or eradication of particular diseases. The policy implications of this are discussed. However, in view of the fact that Thailand lacks a competitive economic advantage in dairy production, doubts are raised about the desirability of protecting and developing this industry in Thailand
Characteristics of Thailand's commercial pig and poultry industries, with international comparisons
Asia contains a heavy concentration of the world's pigs and poultry. It accounts for the major proportion of the world's pig population and that of ducks and geese. It is soon likely to account for the major part of the world's chicken population. Based on FAO statistics, Asia in 1996 possessed 58 percent of the world's pigs, 49 percent of its chicken population and 86 to 88 percent of its ducks and geese. With growing human populations and increased incomes in Asia, populations of these small animals are on the rise. However, conditions and circumstances vary considerably between Asian countries. The situation considered here is in Thailand, a small country by Asian standards but a globally significant exporter of poultry
The influence of firing parameters on the formation of nitride phases in nitride bonded silicon carbides
In this study the influence of parameters like heating rate and dwell time on the kinetics of the nitridation process and microstructural development of nitride bonded silicon carbides was investigated. A combination of in situ and ex situ methods was used with special focus on the spatial formation of nitride phases.The nitridation of SiC–Si green bodies was carried out at heating rates of 1, 3 and 5 K/min and different multi-stage firing profiles were used. All samples were analysed by Raman spectroscopy and SEM. It was observed that with higher heating rates the number of α-Si3N4 whiskers in the matrix was reduced. An effect that was achieved with the direct firing to a temperature above the silicon melting point at 1409 °C as well. However, high heating rates have the disadvantage of a higher amount of residual silicon in the matrix after cooling
Architecture Patterns for Safe Design
The design, prototyping and analysis of complex systems architectures are often very difficult because of their important size. Our modelling experience of several aircraft systems in AltaRica allowed us to exhibit component assemblies whose aim is to ensure the safety of the architectures. The reuse of these assemblies, made generic, that we call Safety Architecture Patterns, simplifies these different tasks. In this paper, we report how SAP allow to obtain a more synthetic view of a system and to exhibit its satisfied properties on an A320like electrical system case study