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The development and sex differences of the catecholaminergic and serotoninergic systems were studied in rat caudate nucleus by measuring dopamine, serotonin and their metabolites in male and female pups from birth up to day 30 of life. Dopamine increased regularly during the entire period studied, while its metabolites, dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), increased sharply only after day 9 of life. At birth, serotonin levels were 50% of the juvenile value; its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), increased greatly after day 6 of life. No difference was observed in male and female neurotransmitter ontogenesis. The results indicated that dopaminergic and serotoninergic systems were not mature in the caudate nucleus at birth. A functional immaturity of enzyme systems involved in neurotransmitter synthesis and/or catabolism is suggested.

Research over the past three decades has shown that the mammalian immune system can be altered by the occupational exposure of asbestos. Early clinical studies generally focused on systemic observations of immune alteration such as the number and function of peripheral lymphocytes and monocytes. More recently as the regulatory influence of local immunity in health and disease becomes more defined, immunologic changes occurring in the lung, the primary target organ of asbestos, have been significant areas of investigation. This review will focus on recent studies that examine the influence of asbestos on pulmonary immunity as well as the role of host immune competence in asbestos-related disease. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Spinacine (4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid), the major reaction product of formaldehyde added to Grana Padano cheese, was administered to five groups of ten rats of each set at dietary concentrations that provided doses of O (control), 15, 30, 60 or 300 mg/kg body weight/day for 13 wk. There were no adverse effects upon survival, growth or food intake. No significant treatment-associated changes were found in haematological parameters, in serum chemistry or organ weights at the end of the study. At autopsy, neither gross nor histological modifications were attributable to treatment with spinacine. In this study the no-effect dose level for spinacine was considered to be 300 mg/kg body weight/day.

Tributyltin (TBT) salts are well known skin irritants in rodents and humans. TBT induced both the intracellular production of interleukin-1alpha (IL-1alpha) and its release into culture medium in a murine keratinocyte cell line (HEL30). Here, we report that mitochondria are important for TBT-induced IL-1alpha production. Confluent cells were treated with increasing concentrations of TBT (0--2.5 microM) or dimethylsulfoxide as vehicle control. At different times thereafter (0--24 h), nuclear extracts were analyzed for nuclear factor-(kappa)B (NF-(kappa)B) binding activity by electrophoretic mobility shift assay, and the released and cell-associated IL-1alpha was measured by enzyme-linked immunosorbent assay. TBT induced a direct and concentration-related activation of NF-(kappa)B, which peaked at 2 h and was blocked by pyrrolidinedithiocarbamate, a potent NF-(kappa)B inhibitor, and rotenone, an inhibitor of the electron entry from complex I to ubiquinone. Rotenone also induced a concentration-related inhibition of IL-1alpha synthesis induced by TBT, but rotenone did not completely abrogate TBT-induced IL-1alpha production, which suggests that other transcription factors may be involved in IL-1alpha production. Prolonged treatment with ethidium bromide, an inhibitor of mitochondrial DNA and RNA synthesis, was used to partially deplete cells of functional mitochondria. After 5 d of treatment, mitochondrial conversion of tetrazolium bromide to formazan was reduced by 50%, and IL-1alpha release was decreased by 65%, whereas no induction of intracellular IL-1alpha was observed. This effect was not due to inhibition of protein synthesis, because identical incorporation of [3H]leucine into protein in control and ethidium bromide-treated cells was identical. This impairment of mitochondrial metabolism inhibited NF-(kappa)B activation by TBT. These findings indicate that mitochondria may be the source of second messenger molecules important for TBT-induced IL-1alpha production.

Little information is available on the reaction products of formaldehyde (FA) with milk components. An isoelectric focusing (IEF) method was developed which detected a unique protein band with pi = 6.7 in defatted Grana Padano cheese samples prepared with FA. The quantity of FA (ppm) added to milk may be extrapolated by calculating the amount of protein associated with this band. The IEF method was rapid, simple, highly specifiC., sensitive, reproducible, inexpensive and easy to utilized in routine controls.

Objective: The purpose of this study was to evaluate the performances of the RHE/IL-18 assay using the SkinEthic™ RHE model for the identification of contact sensitizers. Methods: A set of 18 substances and mixtures was tested on this epidermal model, following the RHE/IL-18 protocol. The final results of the assay were obtained following 5 interpretation schemes, to determine the optimal prediction model for this assay with this specific test system. The data were analysed with a special focus on the basal level of IL-18 release and on the performance obtained with respect to three different gold standards: LLNA, HRIPT and an integrated reference, constructed from all available results. Results: No important differences were found in the performance levels depending on the three gold standards. The performances obtained with the SkinEthic™ RHE model support that this model may be considered as an alternative to different reconstructed epidermis models (EpiDERM™, EpiCS™ and VUMC-EE) for the performance of RHE/IL-18 assays. Conclusion: The prediction model to be used was refined, and more substances have to be tested in order to gather enough data for this evaluation and to determine the right criteria applicable for this assay using the SkinEthic™ RHE test system.

Background Several proteins have been identified as peanut allergens; among them, Ara h 1 (7S globulin) and Ara h 2 (2S globulin) are usually considered the major allergens. Objective To identify the major allergens in a group of children selected for their specific pattern of immunoreactivity. Methods We identified the dominant allergen by using (1) amino acid sequencing of the bands that show the strongest IgE immunoreactivity in 1-dimensional electrophoresis and immunoblotting and (2) specific animal IgGs raised against the dominant immunoreactive band to pinpoint the allergen(s) in peanut proteins separated by 2-dimensional electrophoresis and immunoblotting. To confirm these data, we further examined the peanut proteome using serum samples from the children with the unusual immunoreactivity. Results We found a group of children with marked peanut allergy who are specifically sensitized to the basic subunit of Ara h 3 (11S globulin family). Conclusion That the dominant immunoreactivity in these patients is in a basic subunit of Ara h 3 was unexpected, because previous studies had indicated that Ara h 3 was only a minor peanut allergen and that the identified allergenic epitopes occurred mainly in the acidic Ara h 3 subunit.

Background Over the past fifteen years, we have demonstrated that cortisol and dehydroepiandrosterone (DHEA) have opposite effects on the regulation of protein kinase C (PKC) activity in the context of the immune system. The anti-glucocorticoid effect of DHEA is also related to the regulation of splicing of the glucocorticoid receptor (GR), promoting the expression of GRβ isoform, which acts as a negative dominant form on GRα activity. Moreover, it is very well known that DHEA can be metabolized to androgens like testosterone, dihydrotestosterone (DHT), and its metabolites 3α-diol and 3β-diol, which exert their function through the binding of the androgen receptor (AR). Based on this knowledge, and on early observation that castrated animals show results similar to those observed in old animals, the purpose of this study is to investigate the role of androgens and the androgen receptor (AR) in DHEA-induced expression of the PKC signaling molecule RACK1 (Receptor for Activated C Kinase 1) and cytokine production in monocytes. Results Here we demonstrated the ability of the anti-androgen molecule, flutamide, to counteract the stimulatory effects of DHEA on RACK1 and GRβ expression, and cytokine production. In both THP-1 cells and human peripheral blood mononuclear cells (PBMC), flutamide blocked the effects of DHEA, suggesting a role of the AR in these effects. As DHEA is not considered a direct AR agonist, we investigated the metabolism of DHEA in THP-1 cells. We evaluated the ability of testosterone, DHT, and androstenedione to induce RACK1 expression and cytokine production. In analogy to DHEA, an increase in RACK1 expression and in LPS-induced IL–8 and TNF–α production was observed after treatment with these selected androgens. Finally, the silencing of AR with siRNA completely prevented DHEA-induced RACK1 mRNA expression, supporting the idea that AR is involved in DHEA effects. Conclusions We demonstrated that the conversion of DHEA to active androgens, which act via AR, is a key mechanism in the effect of DHEA on RACK1 expression and monocyte activation. This data supports the existence of a complex hormonal balance in the control of immune modulation, which can be further studied in the context of immunosenescence and endocrinosenescence.