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System Homeostasis (system + homeostasi)
Kinds of System Homeostasis Selected AbstractsNeurotrophins and the immune systemJOURNAL OF ANATOMY, Issue 1 2003José A. Vega Abstract The neurotrophins are a family of polypeptide growth factors that are essential for the development and maintenance of the vertebrate nervous system. In recent years, data have emerged indicating that neurotrophins could have a broader role than their name might suggest. In particular, the putative role of NGF and its receptor TrkA in immune system homeostasis has become a much studied topic, whereas information on the other neurotrophins is scarce in this regard. This paper reviews what is known about the expression and possible functions of neurotrophins and their receptors in different immune tissues and cells, as well as recent data obtained from studies of transgenic mice in our laboratory. Results from studies to date support the idea that neurotrophins may regulate some immune functions. They also play an important role in the development of the thymus and in the survival of thymocytes. [source] Apoptosis, airway inflammation and anti-asthma therapy: From immunobiology to clinical applicationPEDIATRIC ALLERGY AND IMMUNOLOGY, Issue 4 2008Fabrizio Spinozzi T lymphocyte apoptosis is essential for maintaining immune system homeostasis. Experimental evidence suggests apoptosis control mechanisms may be impaired in inflammatory conditions, particularly airway Th2-type allergic diseases. This review briefly examines the mucosal immune system homeostasis and common apoptotic pathways and discusses impaired apoptosis, allergy, airway inflammation, remodelling and fibrosis. Finally, the paper presents an update on pharmacological targeting of apoptosis to control airway inflammation in patients with allergic asthma. [source] The Fas system in the seminiferous epithelium and its possible extra-testicular roleANDROLOGIA, Issue 1 2003A. Riccioli Summary. The Fas system is involved in the control of immune system homeostasis and nonfunctional Fas system leads to autoimmune disease in mice and humans. The Fas system is a mechanism through which cells expressing Fas ligand (FasL) induce apoptosis of Fas expressing cells. In mouse and rat, the testis represents the main source of constitutive FasL in the body. The roles so far proposed for this molecule in the testis, such as maintenance of immunoprivilege and regulation of physiological germ cell apoptosis, need to be reconsidered as both hypotheses are based on an erroneous cellular location of FasL in the seminiferous epithelium. Recently, we demonstrated that in rodents FasL mRNA is present in germ cells and not in Sertoli cells, and that FasL protein is displayed on the surface of spermatozoa. Here we propose that, for the mouse spermatozoa, the FasL may represent a self-defence mechanism against lymphocytes present in the female genital tract. To verify this hypothesis, we performed crossings between males gld, with nonfunctional FasL, and syngenic or nonsyngenic females. We observed a significant decrease of litter size in outbred crossings with gld males compared with wild-type males, suggesting a possible role of FasL in immunoprotection of the sperm in the female genital tract. The possibility that in humans, by analogy with mouse, FasL plays a self-protective role for the spermatozoon cannot be excluded, and awaits experimental information on the expression of FasL on human sperm cells. [source] Clinical evidence of benefits of a dietary supplement containing probiotic and carotenoids on ultraviolet-induced skin damageBRITISH JOURNAL OF DERMATOLOGY, Issue 3 2010D. Bouilly-Gauthier Summary Background,Lactobacillus johnsonii (La1) has been reported to protect skin immune system homeostasis following ultraviolet (UV) exposure. Objectives, To assess the effects of a dietary supplement (DS) combining La1 and nutritional doses of carotenoids on early UV-induced skin damage. Methods, Three clinical trials (CT1, CT2, CT3) were performed using different UV sources: nonextreme UV with a high UVA irradiance (UV-DL, CT1), extreme simulated solar radiation (UV-SSR, CT2) and natural sunlight (CT3). All three clinical trials were carried out in healthy women over 18 years of age with skin type II,IV. In CT1, early markers of UV-induced skin damage were assessed using histology and immunohistochemistry. In CT2, the minimal erythemal dose (MED) was determined by clinical evaluation and by chromametry. Chromametry was also used to evaluate skin colour. Dermatologists' and subjects' assessments were compiled in CT3. Results, A 10-week DS intake prevented the UV-DL-induced decrease in Langerhans cell density and the increase in factor XIIIa+ type I dermal dendrocytes while it reduced dermal inflammatory cells. Clinical and instrumental MED rose by 20% and 19%, respectively, and skin colour was intensified, as shown by the increase in the ,E* parameter. The efficacy of DS was confirmed by dermatologists and subjects under real conditions of use. Conclusions, Nutritional supplementation combining a specific probiotic (La1) and nutritional doses of carotenoids reduced early UV-induced skin damage caused by simulated or natural sun exposure in a large panel of subjects (n = 139). This latter result might suggest that DS intake could have a beneficial influence on the long-term effects of UV exposure and more specifically on skin photoageing. [source] |