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Immunological Activation (immunological + activation)
Selected AbstractsRole of macrophage activation in the pathogenesis of Alzheimer's disease and human immunodeficiency virus type 1-associated dementiaEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2000Smits The structure and function of neurons are changed not only during development of the central nervous system but also in certain neurological disorders, such as Alzheimer's disease and human immunodeficiency virus type 1 (HIV-1) -associated dementia. Immunological activation and altered production of neurotoxins and neurotrophins by brain macrophages are thought to play an important role in neuronal structure and function. This review describes the clinical and pathological features of both Alzheimer's disease and HIV-1-associated dementia and tries to interpret the role of the macrophage and astrocytes therein. The consequences of activation of macrophages by amyloid-, in Alzheimer's disease and HIV infection of macrophages in HIV-1-associated dementia and the similarities between these diseases will be discussed. Although the neuropathology of Alzheimer's disease and HIV-1-associated dementia differs, Alzheimer's disease is a cortical dementia and HIV-1-associated dementia is a subcortical dementia, the process of macrophage activation and the resulting pathways leading to neurotoxicity seem very similar. In both Alzheimer's disease and HIV-1-associated dementia, interaction of macrophages and astrocytes appear to play an important role. [source] Infiltrating cells and related cytokines in lesional skin of patients with chronic idiopathic urticaria and positive autologous serum skin testEXPERIMENTAL DERMATOLOGY, Issue 5 2003M. Caproni Abstract:, In approximately one-third of patients with chronic idiopathic urticaria (CIU), autoantibodies against the high-affinity IgE receptor and/or against IgE can be detected and a wheal-and-flare response can be provoked by the intradermal injection of autologous serum (ASST). In this study we aimed to further characterize the inflammatory response observed in the subgroup of CIU patients with positive ASST and serum-evoked histamine-release in vitro from basophils in comparison with unaffected skin and healthy donors. An immunohistochemical analysis of infiltrating cells (CD4, MPO, EG1, EG2, tryptase), cytokines (IL-4, IL-5, IFN-,), chemokines and chemokine receptors (IL-8, CCR3, CXCR3), and adhesion molecules (ICAM-1, VCAM-1, ELAM-1) was performed on seven selected patients (four males and three females; median age: 45 years; range: 22,57) and five healthy donors. Cytokine evaluation was also performed in five psoriatic patients to obtain an additional control. In spontaneous wheals we observed an increased number of CD4+ T lymphocytes when compared with the controls, and an increased number of neutrophils and eosinophils, whereas mast cells did not show a significant variation. A significant expression for IL-4 and IL-5 could only be observed in lesional skin, while IFN-, showed a slight expression in the same site. Chemokine receptors CCR3 and CXCR3 did not show a defined polarized response in either lesional or unaffected skin. An increased expression of all cellular adhesion molecules (CAMs) studied was detected in spontaneous wheals. The lack of a significant difference in the expression of tryptase + mast cells, T lymphocytes, IL-8, CXCR3 and CCR3, a few CAMs between the lesional and unaffected skin of CIU patients suggests a wide immunological activation that involves not only lesional tissues, but possibly extends to the whole of the skin's immune system. [source] Soluble Interleukin-2 Receptors Increase During the Active Periods in Cluster HeadacheHEADACHE, Issue 1 2003M. Empl MD Objective.,To investigate whether cytokines are altered during the active period of cluster headache. Background.,Patients with cluster headache show activation of the hypothalamus in PET studies and via endocrinologic parameters. Data also suggest an inflammatory process occurs in cluster headache. A connection between the presumed inflammatory cause, an immunological activation, and the hypothalamus could be generated by certain cytokines. Design and Methods.,ELISA was used to determine the serum levels of soluble interleukin-2 receptors, interleukin-1, interleukin-6, and 2 soluble interleukin-6 receptors (sIL-6R and soluble gp130) in 18 patients with cluster headache (6 women and 12 men) during the cluster period and in 17 healthy controls who were headache-free (3 women and 14 men). Results.,Patients with cluster headache had significantly increased soluble interleukin-2 receptors (413.6±223 U/mL vs. 290.0±112 U/mL; P < .05) compared with controls. Serum levels of interleukin-1 (0.29±0.30 pg/mL vs. 0.13±0.13 pg/mL, n.s.), interleukin-6 (0.87±0.6 pg/mL vs. 0.91±0.7 pg/ml; n.s.), soluble interleukin-6 receptors (33,131±8,349 pg/mL vs. 35,063±7,606 pg/mL; n.s.), or soluble gp130 (289±59 pg/mL vs. 283±20 pg/mL; n.s.) did not differ between the 2 groups, although patients with cluster tended to have higher interleukin-1 values. Conclusions.,Because elevated soluble interleukin-2 receptors indicate T cell activation, our findings suggest immune activation during cluster headache. Because interleukin-2 can activate the hypothalamus and stimulate the release of Corticotropin-releasing Factor (CRF), interleukin-2 could link a putative immunological cause of cluster headache with the observed hypothalamic activation. Systemic changes of interleukin-1 or the interleukin-6 system do not seem to play a role in cluster headache, as no alterations of serum levels were observed. Even so, unchanged serum levels do not exclude limited local production. [source] Enhancement of natural killer (NK) cell cytotoxicity and induction of NK cell-derived interferon-gamma (IFN- ,) display different kinetics during experimental infection with Trypanosoma cruziCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2000C. Une Early immunological activation involves an initial phase of cytokine activity and involvement of cell types such as NK cells. Such early immune responses are often decisive in resolution of microbial infection. NK cells reduce parasitaemia and enhance survival in experimental Trypanosoma cruzi infection, although the nature of these protective effects is not well understood. In this study, a detailed analysis of innate cytokine induction in the absence and presence of NK cells during the first 8 days of infection was performed. Following intraperitoneal infection with a high dose of parasites, reverse transcriptase-polymerase chain reaction showed that splenic mRNA for IFN- , appeared as a peak 24 h after infection and then reappeared 2,3 days later. In NK-depleted animals the first peak of IFN- , was absent and the second wave was slightly delayed. mRNA for IL-12 and tumour necrosis factor-alpha (TNF- ,) as well as IFN- , protein in serum was only recorded 24 h after infection, at the same time as the IFN- , peak. NK depletion resulted in a small decrease of IL-12 mRNA levels, whereas TNF- , and IFN- , were not affected. NK cytotoxicity remained elevated throughout the 8 days and thus did not parallel the expression of IFN- , production by NK cells. We conclude that NK cell cytokine production and cytolytic activity play different roles in response to challenge with T. cruzi. [source] | ||||||||||