668 research outputs found

    Probiotics: immunomodulation and evaluation of safety and efficacy.

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    The intake of probiotics has been associated with beneficial effects on the immune system, such as improved disease resistance and diminished risk of allergies. This review gives an overview of the immunomodulatory effects of probiotics investigated with in vitro assays, experimental animal models, and clinical trials, and explores possible mechanisms underlying the immunomodulatory effects. Immunomodulation, however, is not always beneficial and might induce detrimental effects; therefore, a scheme is proposed for benefit-risk assessment of immunomodulation by probiotics. Within this scheme, expert judgment based on data derived from a panel of in vitro assays, animal models, and clinical trials should lead to conclusions on efficacy and safety aspects of probiotics

    VßGene Family Usage in Spontaneous Lymphomas of AKR Mice: Evidence for Defective Clonal Deletion

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    T-cell receptor (TCR) ß-chain usage and expression of the CD3, CD4, and CD8 differentiation antigens were analyzed in 14 spontaneous AKR lymphomas. Lymphoma cells massively infiltrated and/or proliferated in the organs analyzed (thymus, spleen, and mesenteric lymph nodes), giving rise to a loss of organ structure. One lymphoma occurred only in the thymus, and failed to express CD3, CD4, and CD8. All other lymphomas expressed the CD3/TCR complex. With respect to CD4 and CD8 expression, the lymphomas were either double-negative (DN), double-positive (DP), or single-positive (SP). The frequency of DP (CD4+8+) lymphomas was low compared to the frequency of DP thymocytes in a normal AKR thymus. A substantial heterogeneity was seen in the intensity of CD4 and CD8 expression among various lymphomas, which was independent of the level of CD3 expression. Considering TCR V ß gene family usage, 2 out of 14 lymphomas expressed V ß6. Normally, V ß6+ thymocytes are deleted from the thymocyte pool at the immature DP stage of T-cell development in AKR mice. These data support the hypothesis that the lymphocytes in the immature DP stage of T-cell development are susceptible to the induction of AKR lymphomagenesis. The presence of V ß6+ lymphoma cells indicates that the lymphomagenesis is accompanied by a defective clonal deletion of cells expressing a possible autoreactive TCR

    Immunotoxic effects of chemicals: A matrix for occupational and environmental epidemiological studies.

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    BACKGROUND: Many biological and chemical agents have the capacity to alter the way the immune system functions in human and animals. This study evaluates the immunotoxicity of 20 substances used widely in work environments. METHODS: A systematic literature search on the immunotoxicity of 20 chemicals was performed. The first step was to review literature on immunotoxicity testing and testing schemes adopted for establishing immunotoxicity in humans. The second step consisted of providing a documentation on immunotoxicity of substances that are widely used in work environment, by building tables for each chemical of interest (benzene, trichloroethylene, PAHs, crystalline silica, diesel exhausts, welding fumes, asbestos, styrene, formaldehyde, toluene, vinyl chloride monomer, tetrachloroethylene, chlorophenols, 1,3-butadiene, mineral oils, P-dichlorobenzene, dichloromethane, xylene, 1,1,1-trichloroethane, ethylene oxide). The third step was the classification of substances; an index (strong, intermediate, weak, nil) was assigned on the basis of the evidence of toxicity and type of immunotoxic effects (immunosuppression, autoimmunity, hypersensitivity) on the basis of the immune responses. Finally substances were assigned a score of immunotoxic power. RESULTS: Tables have been produced that include information for the 20 substances of interest, based on 227 animal studies and 94 human studies. Each substance was assigned an index of immunotoxic evidence, a score of immunotoxic power and type of immunotoxic effect. CONCLUSIONS: This matrix can represent a tool to identify chemicals with similar properties concerning the toxicity for the immune system, and to interpret epidemiological studies on immune-related diseases

    Мінливість дуже сильних дощів і сильних злив в Україні

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    Розглянуто міжрічну мінливість кількості випадків стихійних гідрометеорологічних явищ (СГЯ), а саме: дуже сильних дощів і сильних злив – в Україні та її регіонах у другій половині ХХ – на початку ХХІ ст. Використавши методи сезонної декомпозиції, встановлено тенденцію динаміки цих рядів протягом досліджуваного періоду. Шляхом автокореляційного та спектрального аналізів визначено циклічні компоненти у структурі рядів річної кількості випадків СГЯ та їх особливості в періоди, коли спостерігали тенденцію до зменшення і збільшення інтенсивності цих явищ.Рассмотрена межгодовая изменчивость количества случаев очень сильных дождей и сильных ливней в Украине и ее регионах во второй половине ХХ - в начале ХХІ в. Установлена тенденция динамики этих рядов на протяжении исследуемого периода. Определены циклические компоненты в структуре рядов годового количества случаев стихийных осадков (СГЯ) и их особенности в периоды, когда наблюдали тенденцию к уменьшению и увеличению интенсивности этих явлений

    Ultraviolet Radiation-Induced Impairment of the Early Initiating and the Late Effector Phases of Contact Hypersensitivity to Picrylcholoride: Regulation by Different Mechanisms

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    Two types of antigen-specific T cells are needed for the elicitation of contact hypersensitivity reactions. They act in an obligate sequence to mediate the early initiating and late effector phases of contact hypersensitivity, which are accompanied by skin-swelling responses at 2 and 24h after challenge, respectively. The magnitude of the late ear swelling depends on that of the early swelling.We studied the influence of ultraviolet radiation on both phases of contact hypersensitivity to picrylchloride. Mice were exposed to subedemal doses of ultraviolet radiation on the shaved backs for four consecutive days. Four days later mice were sensitized on non-irradiated skin. Four days after sensitization mice were challenged on the ears, and swelling was measured 2, 4, and 24h after challenge. The early and late phases of contact hypersensitivity were largely suppressed in ultraviolet-irradiated, actively sensitized mice. Transfer of immune lymphoid cells from donor mice that were sensitized 4 d earlier induced early and late components of contact hypersensitivity in naive recipients after challenge. Transfer of immune lymphoid cells from donors that were sensitized 1 d earlier only induced the early component of contact hypersensitivity. Ultraviolet irradiation of donor mice significantly reduced the capacity of the immune lymphoid cells to induce contact hypersensitivity. We show that lymphoid cells responsible for the early and late components of contact hypersensitivity are both affected

    Repeated Doses of UVR Cause Minor Alteration in Cytokine Serum Levels in Humans

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    The aim of our study was to compare serum concentration of IL-1β, IL-6, IL-8, IL-10, and TNF-α in 105 healthy volunteers before and after exposure to UVR: 25 subjects (10 days of UVB), 55 (10 days of UVB or solar-simulated radiation, followed by acute UVB dose), and 25 (local high dose of UVB). In all the individuals blood samples were analyzed before and after final irradiation by chemiluminescence assay. After 10 days of UVB irradiation a statistically significant increase in serum concentration only in IL-8 (P < .05) and strong tendency in TNF-α (P = .05) were observed. The applied schedules of irradiation have minor impact on serum cytokine level and still a threshold dose of UVR causing systemic immune impairment is unknown

    Адаптація в українській термінології іншомовних лексем на позначення засобів розміщення туристів

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    Розглянуто шляхи та причини запозичення іншомовної лексики на позначення засобів розміщення туристів, подано значення окремих запозичених лексем.The article studies the ways and reasons for lexical units denoting tourist accommodation borrowing. The meanings of some borrowed terms are given
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