Contact-allergy time

The most commonly used techniques for the in vivo evaluation of the cellular immune response include intracutaneous testing with microbial recall antigens or sensitization with neoantigens. The reliability of these tests for the individual patient usually is low due to the lack of standardization and quantification. Moreover only the efferent branch of the immune response can be judged. The dinitrochlorobenzene-contact allergy time (DNCB-CAT) is a quantitative approach for the assessment of the cellular immune response. 2% DNCBointment is applied on the upper arm in a 1 cm2 area. On the following days patch-testing with 0.05% DNCB-ointment is done on the homolateral forearm in alternating localizations till an allergic contact dermatitis reaction appears. As assessed in patients with malignant melanoma (MM, n=\\5) and with lymphoproliferative disorders (LD, η = 25), the DNCB-CAT correlates with the age of the patients and can be expressed by a formula given by the age (years) χ factor (MM = 0.16; LD = 0.17) + constant figure (MM = 5.5; LD = 4.3). There was no significant difference between the two groups or subgroups investigated. By DNCB-CAT quantitative analysis of the cellular immune response in vivo is possible. It is an appropriate model for further investigations of the cellular immunity under different clinical, histological, prognostic, and therapeutic aspects

Pollen grains induce a rapid and biphasic eczematous immune response in atopic eczema patients

Introduction: Eczematous reactions to type I allergy-inducing antigens are documented in a subgroup of patients with atopic eczema. Yet, the underlying immunological mechanisms are not well understood. Material and Methods: To delineate the effect of native pollen grains on human skin of healthy and atopic individuals we performed patch tests (atopy patch test with native pollen grains, PPT). Nickel patch tests (NPT) served as an established model of contact dermatitis. Skin site biopsies were taken 6 - 96 h after allergen application and investigated immunohistochemically. Results: Histology of positive patch tests showed an influx of mononuclear cells (predominantly CD4+, CD25+, CD45RO+). This influx was detected earlier in the PPT reaction than in the immune response to nickel. A biphasic cytokine response could be detected in the PPT: IL-5 dominated in the early, IFN-gamma in the late phase. The NPT was continuously dominated by IFN-gamma. Dendritic cell subpopulations imitated the earlier kinetics of the mononuclear infiltrate. Discussion: Thus, pollen grains induce eczematous reactions in susceptible individuals. This reaction appears clinically and immunohistochemically similar to the contact hypersensitivity reaction to nickel but follows a faster kinetic and a biphasic course: Th2 and IgE in the early (24 h) and Th1 predominance in the late (96 h) phase. Copyright (c) 2007 S. Karger AG, Basel

Oligocene emplacement of the Eclogite Zone of the central Tauern Window, Eastern Alps, Austria

The EZ is an approximately 20km long and 2–3km wide coherent unit of the Tauern Window in the Eastern Alps. It is sandwiched between the Venedigerand the Glockner Nappe. While rocks in the EZ experienced HP metamorphic conditions (24 kbar/650°C), rocks from the underlying Venediger Nappe and the overlying Glockner Nappe only record lower alpine metamorphic conditions with peak pressures not exceeding 10 and 8 kbar, respectively. While metamorphism in the EZ is well dated with an average age of 31.5±0.7Ma (Glodny et al. 2005) the final emplacement of these different nappes is still under debate. Our Rb-Sr-data indicate that top-N thrusting at the base and large-scale folding of the EZ was coeval with sinistral strike-slip faulting at its upper boundary and eclogite-facies metamorphism in the EZ. The data also indicate that today’s nappe architecture must have been established in less than 2Ma after the eclogite facies metamorphism in the EZ. Very fast exhumation of the EZ was accomplished in a transpressional setting, which might explain why the exposed EZ is such a small unit.conferenc

Between Scylla and Charybdis - on the place of economic methods and concepts within ecological economics

Ecological Economics inherently faces a challenge akin to sailing between Scylla and Charybdis. In Greek mythology these are two monsters located on opposite sides of a narrow strait, and falling victim to one or other of them is unavoidable. In the recurring process of establishing and refining its conceptual foundations, Ecological Economics runs the risk of, on the one hand, losing important insights by trying to be radically different from mainstream economics and, on the other hand, becoming a redundant appendix to mainstream environmental economics by routinely applying its concepts and methods. We argue that avoiding both fallacies is possible by using Ecological Economics’ orientation towards sustainability as a guiding principle. The scientist’s power of judgment supports her decision concerning which methods are suitable for tackling a given sustainability problem. The intersubjective quality of judgment prevents the resulting methodological pluralism from drifting toward arbitrariness

Petrochronology of polygenetic white micas (Naxos, Greece)

Naxos in the Greek Cyclades preserves a type example of polymetamorphism. The southern and northern parts of the island record different Tertiary P–T histories between Eocene and Miocene times, including a blueschist facies event, one or more amphibolite/greenschist facies overprint(s) and contact metamorphism. Age attributions for these events are inconsistent in the literature. Here, we propose a new approach that combines electron probe microanalyzer (EPMA) characterization of the white mica (WM) with $^{39}$Ar-$^{40}$Ar–Rb-Sr multichronometry. Textural–petrographic–compositional observations reveal that the polygenetic WM consists of five different generations: pre-Eocene relicts, paragonite, high-Si phengite, low-Si phengite and muscovite. EPMA mapping of four WM samples, previously analysed by Rb-Sr, reveals major element compositions heterogeneous down to the μm scale. Each WM consists of chemically distinct generations, documenting submicron-scale retrogression of high-pressure (HP) phengite grains to muscovite. Four WM samples from a N-S traverse across the island were analysed by $^{39}$Ar-$^{40}$Ar stepheating, comparing coarse and fine sieve size fractions to obtain overdetermined K-Ar systematics. Fine sieve fractions are richer in Cl than coarse ones. Linear arrays in Cl/K-age isotope correlation diagrams show two predominant WM generations (one Cl-poor at ca. 38 Ma and one Cl-rich at <20 Ma). A lower-grade sample from southern Naxos was less pervasively recrystallized, provides older ages and preserves at least three WM generations, including a relict WM with a pre-Palaeocene K-Ar age, consistent with the high Ar retentivity of WM in the absence of complete recrystallization. The age of the Cl-poor end-member WM approximates the age of the HP event, 38 Ma. Ar inheritance in Cretaceous mica relicts is heterogeneous at the single-grain scale. Comparing the degassing rates of the WM fractions rules out ‘multidomain’ diffusion. As no sample is monomineralic, the degassing rate of each polygenetic mica is instead controlled by the mass balanced sum of the unrelated rate constants of its constituent minerals. Given the commonness of zoned and composite micas, the approach detailed here is potentially useful for reconstructing polyphase metamorphic histories worldwide

Chloracne: From clinic to research

AbstractChloracne is the most sensitive and specific marker for a possible dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) intoxication. It is clinically characterized by multiple acneiform comedone-like cystic eruptions mainly involving face in the malar, temporal, mandibular, auricular/retroauricular regions, and the genitalia, often occurring in age groups not typical for acne vulgaris. Histopathology is essential for a definite diagnosis, which exhibits atrophy or absence of sebaceous glands as well as infundibular dilatation or cystic formation of hair follicles, hyperplasia of epidermis, and hyperpigmentation of stratum corneum. The appearance of chloracne and its clinical severity does not correlate with the blood levels of dioxins. Pathogenesis of chloracne remains largely unclear. An “aryl hydrocarbon receptor”-mediated signaling pathway affecting the multipotent stem cells in the pilosebaceous units is probably the major molecular mechanism inducing chloracne. Chloracne is resistant to all the available treatment modalities used to treat acne. The aim of treatment is to lower or to eliminate the accumulated dioxins in the body at the very beginning of intoxication, e.g., by using dioxin-chelating substances such as synthetic dietary fat substitutes. The problem of dioxin contamination and its potential health hazards should be taken seriously in the wave of industrial globalization in the twenty-first century. Clinicians, especially dermatologists, are in the forefront of early diagnosis of dioxin intoxication

Alterations of Glucosylceramide-β-Glucosidase Levels in the Skin of Patients with Psoriasis Vulgaris

Hydrolysis of glucosylceramides by the enzyme glucosylceramide-β-glucosidase (GlcCer'ase) results in ceramide, a critical component of the intercellular lamellae that mediates the epidermal permeability barrier. A disturbance of ceramide formation is supposed to influence the transepidermal water loss in common skin diseases like atopic eczema or psoriasis. The aim of this study was to investigate whether GlcCer'ase levels were altered in the skin of subjects with psoriasis vulgaris. Skin punch biopsies were taken from lesional and non-lesional psoriatic skin and GlcCer'ase was evaluated both at the RNA and at the protein level. Normal skin from surgical patients provided the baseline GlcCer'ase expression in healthy subjects. Our results show that GlcCer'ase mRNA expression was decreased in psoriatic non-lesional skin compared to normal controls in all cases. Interestingly, in lesional psoriatic skin the level of GlcCer'ase was increased compared to non-lesional skin in all cases. For the immunohistochemical analysis, we used a newly synthesized monoclonal antibody anti-human GBC (GlcCer'ase-GST fusion protein). The results confirmed that GlcCer'ase, mainly present in the upper epidermis, was decreased in psoriatic skin compared to normal control and was increased in lesional compared to non-lesional psoriatic skin. Our findings support the concept that alteration in water permeability barrier in lesional psoriatic skin can serve as a trigger for the upregulation of the expression of enzymes like GlcCer'ase with consequent stimulation of ceramide generation

Pollen allergens do not come alone: pollen associated lipid mediators (PALMS) shift the human immue systems towards a TH2-dominated response

Pollen allergy is characterized by a TH2-biased immune response to pollen-derived allergens. However, pollen-exposed epithelia do not encounter pure allergen but rather a plethora of protein and non-protein substances. We demonstrated that pollen liberate lipids with chemical and functional similarities to leukotriens and prostaglandins - the pollen associated lipid mediators (PALMs). To date, two main groups of PALMs have been characterized: The immunostimulatory PALMs activating innate immune cells such as neutrophils and eosinophils, and the immunomodulatory E1-phytoprostanes blocking IL-12 production of dendritic cells, resulting in the preferential induction of TH2 responses. This article reviews our work in the field of PALMs and their effects on cells of the innate and adoptive immune system. From recent results a general picture starts to emerge in which PALMs (and possibly other pollen-associated substances) may - independently from protein allergens - propagate an overall TH2 favoring micromilieu in pollen exposed tissue of predisposed individuals

Pollen-associated phytoprostanes inhibit dendritic cell interleukin-12 production and augment T helper type 2 cell polarization

Pollen grains induce allergies in susceptible individuals by release of allergens upon contact with mucosal membranes of the upper respiratory tract. We recently demonstrated that pollen not only function as allergen carriers but also as rich sources of bioactive lipids that attract cells involved in allergic inflammation such as neutrophils and eosinophils. Here we demonstrate that soluble factors from birch (Betula alba L.) pollen activate human dendritic cells (DCs) as documented by phenotypical and functional maturation and altered cytokine production. Betula alba L. aqueous pollen extracts (Bet.-APE) selectively inhibited interleukin (IL)-12 p70 production of lipopolysaccharide (LPS)- or CD40L-activated DC, whereas IL-6, IL-10, and TNFα remained unchanged. Presence of Bet.-APE during DC activation resulted in DC with increased T helper type 2 (Th2) cell and reduced Th1 cell polarizing capacity. Chemical analysis of Bet.-APE revealed the presence of phytoprostanes (dinor isoprostanes) with prostaglandin E1-, F1-, A1-, or B1-ring systems of which only E1-phytoprostanes dose dependently inhibited the LPS-induced IL-12 p70 release and augmented the Th2 cell polarizing capacity of DC. These results suggest that pollen-derived E1-phytoprostanes not only resemble endogenous prostaglandin E2 structurally but also functionally in that they act as regulators that modulate human DC function in a fashion that favors Th2 cell polarization