Seasonal changes in suppressive capacity of CD4+ CD25+ T cells from patients with hayfever are allergen-specific and may result in part from expansion of effector T cells among the CD25+ population.

BACKGROUND: Suppression of allergen-stimulated peripheral blood CD4(+) CD25(-) effector T cells by CD4(+) CD25(+) regulatory T cells obtained from subjects with allergic rhinoconjunctivitis is reduced during the pollen season when compared with out of season. OBJECTIVE: We examined possible explanations for this effect of seasonal pollen exposure on suppression of allergen responses. METHODS: CD4(+) CD25(-) and CD4(+) CD25(+) T cells were isolated from blood obtained from 44 volunteers with allergic rhinoconjunctivitis during and out of the UK grass pollen season. Co-cultures were performed with grass pollen extract and house dust mite (HDM) to examine allergen specificity. The frequency of IL-5 and IL-10 producing cells was determined by ELISPOT and the expression of T cell activation markers and the CD25(+) regulatory T cell-associated transcription factor Foxp3 were examined. Lactic acid stripping of IgE was used to determine IgE dependence of T cell responses. RESULTS: The seasonal reduction in suppression by CD4(+) CD25(+) T cells was confirmed and was shown to be allergen specific because suppression of HDM-stimulated cultures was not affected significantly. The CD4(+) CD25(+) population contained IL-5 and IL-10 producing cells but increases in their frequencies with seasonal pollen exposure were not significant. Both activation marker and Foxp3 expression increased during the pollen season. IgE stripping reduced CD4(+) and CD4(+) CD25(-) T cell responses to allergen, but had no effect on suppression by CD4(+) CD25(+) T cells. CONCLUSION: The seasonal reduction in suppression of grass pollen-stimulated effector T cells by CD4(+) CD25(+) T cells is allergen specific and cannot be explained by increased IgE-facilitated allergen presentation. We suggest that changes in the proportion of effector to regulatory T cells among the CD25(+) population isolated may partially explain these findings, and that trafficking to the site of allergic disease may reduce allergen-specific regulatory T cell numbers in peripheral blood.

Organ transplantation and European Community law: the case of non-residents.

OBJECTIVES: The role of the European Union in influencing health care policies in member states is of increasing importance. The Eurotransplant Foundation is an organization which provides donor organs to the most suitable transplant recipients. It covers a region of five countries (Austria, Belgium, Germany, Luxembourg, The Netherlands). As there is a severe shortage of donor organs within its region, registration of so-called non-resident patients on the waiting lists aggravates this shortage. Could European Community law, especially rules on competition, limit Eurotransplant's freedom to introduce a restrictive policy on non-residents? If so, could participating transplant centres or patients initiate legal action against Eurotransplant to stop the execution of such a policy? METHODS: Quantitative descriptive data on organ donation and use by the Eurotransplant Foundation during 1994 and 1995, by residents and non-residents. Analysis on basis of economic and legal framework. RESULTS: Solidarity between potential donors and potential recipients is organized in a different manner in an organization such as Eurotransplant as compared to a national organization under national law. National regulations may introduce a restrictive policy for the acceptance of non-resident patients. Eurotransplant--as a matter of its own policy--has to consider international solidarity. The scope of the non-resident issue is dealt with, and it is explained why it is considered to be a problem. On the basis of a discussion of the economic and the legal framework for a non-resident policy, an answer to the question is suggested. CONCLUSION: It might be possible for Eurotransplant to introduce a restrictive policy on the admission of non-residents without violating the European Community Treaty.

Transboundary effects on health care services in the European Community.

This article deals with the rights that community law gives to the medical and allied professions to exercise their professional activities in a member state other than their state of origin. Firstly, the scope of the general economic provisions of the European Community (EC) Treaty is broadly described. Secondly, the specific rules of the EC secondary legislation concerning the harmonization of the national legislations on professional qualifications in the health care sector are reviewed. Lastly, an example is given of the application of these rules in the health care sector by the Court of Justice of the European Community. It is submitted that the exercise of these rights can contribute to transboundary cooperation within the EC in the rendering of health care services to patients in the member states. This is specially relevant in frontier areas.

[Nephrotoxicity of mitomycin C (apropos of 25 case reports). Results of a multicenter survey organized by the Society of Nephrology]. / La néphrotoxicité de la mitomycine C (à propos de 25 observations). Résultats d'une enquête multicentrique organisée par la Société de néphrologie.

We have studied 25 cases of hemolytic and uremic syndrome (H.U.S.) induced by mitomycin C, collected from 1976 to 1982 in 12 Nephrology Centers. Mitomycin C was administered in successive cures at a cumulative dose higher than 50 mg/m2. This H.U.S. is characterized by its slow and late occurrence, by extra-renal, mainly respiratory, manifestations that may reveal the disease, and finally by its pathological aspects. Mesangiolysis and endothelial or mesangial enlarged and atypical nuclei are observed in addition to the usual lesions of thrombotic micro-angiopathy. The prognosis was very poor in the first cases reported. It was better, however, in the patients studied more recently, because the cumulative dose was lower. In severe cases, plasma exchange might improve long-term prognosis. The disease might be due to a direct toxic effect of mitomycin C on the vascular endothelium.

Closed cycle cryogenic refrigerators as integrated cold sources for infrared detectors.

Many ir detectors can only operate when cooled to low temperatures. A short description is given of an integrated refrigerator-detector combination in airborne use. Experimental results are presented for developmental refrigerators in which weight and power input have been reduced to a point where satellite- borne operation becomes feasible.

Effective thickness of bulk materials and of thin films for internal reflection spectroscopy.

In internal reflection spectroscopy effective thickness is defined as the thickness of material required to give a spectrum of the same contrast in a transmission measurement as that obtained via internal reflection. Simple expressions for effective thickness are given for bulk materials and for thin films which are useful as guide lines in determining the optimum conditions required to record internal reflection spectra. Depending on angle of incidence and index of refraction, the effective thickness for bulk materials may be much greater or much less than the wavelength of light. Similarly for thin films the effective thickness may be much greater or much less than the actual thickness.