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Cell Peptides (cell + peptide)
Selected AbstractsImportant roles for epithelial cell peptides in hydra developmentBIOESSAYS, Issue 6 2009Toshio Takahashi Abstract It has been convincingly shown that peptides play important roles in the regulation and maintenance of a variety of tissues and organs in living animals. However, little is known concerning the potential role of peptides as signaling molecules in developmental processes. In Hydra, there is circumstantial evidence that small diffusible molecules act as morphogens in the regulation of patterning processes. In order to view the entire spectrum of peptide signaling molecules, we initiated a project aiming at the systematic identification of peptide signaling molecules in Hydra. In this review, we describe three peptide signaling molecules and one family of peptides that function as signaling molecules in the processes of axial pattern formation and neuron differentiation in Hydra. These peptides are produced by epithelial cells and are therefore termed "epitheliopeptides". We discuss the importance of epitheliopeptides in developmental processes within a subset of hydrozoans. [source] Developments in allergen-specific immunotherapy: from allergen extracts to allergy vaccines bypassing allergen-specific immunoglobulin E and T cell reactivityCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2010M. Focke Summary Allergen-specific immunotherapy (SIT) is the only specific and disease-modifying approach for the treatment of allergy but several disadvantages have limited its broad applicability. We argue that the majority of the possible disadvantages of SIT such as unwanted effects, poor efficacy and specificity as well as inconvenient application are related to the poor quality of natural allergen extracts, which are the active ingredients of all currently available allergy vaccines. Because of the progress made in the field of molecular allergen characterization, new allergy vaccines based on recombinant allergens, recombinant hypoallergenic allergen derivatives and allergen-derived T cell peptides have entered clinical testing and hold promise to reduce the side-effects and to increase the specificity as well as the efficacy of SIT. Here, we present a refined immunotherapy concept, which is based on the use of peptides derived from allergen surfaces that exhibit reduced, allergen-specific IgE as well as T cell reactivity. These peptides when fused to non-allergenic carriers give rise to allergen-specific protective IgG responses with T cell help from a non-allergenic carrier molecule. We summarize the experimental data demonstrating that such peptide vaccines can bypass allergen-specific IgE as well as T cell activation and may be administered at high doses without IgE- and T cell-mediated side-effects. Should these peptide vaccines prove efficacious and safe in clinical trials, it may become possible to develop convenient, safe and broadly applicable forms of SIT as true alternatives to symptomatic, drug-based allergy treatment. Cite this as: M. Focke, I. Swoboda, K. Marth and R. Valenta, Clinical & Experimental Allergy, 2010 (40) 385,397. [source] The effects of T cell peptides in patients sensitive to catsCLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 2004Mark Larché Summary Synthetic peptides representing T cell epitopes of the major cat allergen Fel d 1 were administered by intradermal injection or inhalation to cat allergic asthmatic volunteers. Both routes of administration were associated with the induction of IgE-independent, MHC-restricted isolated late asthmatic reactions (LAR; prolonged bronchoconstriction initiating 2,4 hours after peptide challenge) in a proportion of individuals. Administration via the intradermal, but not the inhaled route, was associated with the induction of antigen-specific hyporesponsiveness or "tolerance", both in vivo and in vitro. Following intradermal peptide administration, the magnitude of both the early- and late-phase skin reaction to intradermal challenge with whole allergen extract were significantly reduced. In vitro, proliferative responses of peripheral blood mononuclear cells (PBMC) were reduced together with both Th1 and Th2 cytokines. Production of IL-10 was increased. LAR were not a pre-requisite for the induction of tolerance. Hyporesponsiveness was transient but several months were required to return to basal reactivity. [source] Clinical features and morphological characterization of 10 patients with noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS)CLINICAL ENDOCRINOLOGY, Issue 5 2006Justin G. S. Won Summary Objective, Noninsulinoma pancreatogenous hypoglycaemia syndrome (NIPHS), characterized by postprandial neuroglycopaenia, negative prolonged fasts and negative perioperative localization studies for insulinoma, but positive selective arterial calcium stimulation tests and nesidioblastosis in the gradient-guided resected pancreas, is a rare hypoglycaemic disorder of undetermined aetiology. We analysed the clinical, morphological and immunohistological features to further clarify the aetiology and pathogenesis of this rare disease. Patients, Ten consecutive patients with NIPHS (nine men and one woman, aged 29,78 years) were included in the study. Six of the 10 received a gradient-guided subtotal (70%) or distal (50%) pancreatectomy. In the remaining four patients, diazoxide treatment was initiated and the precise mechanism of its action was assessed by meal tests. Results, All of the patients showed a combination of postprandial neuroglycopaenia, negative prolonged fasts (except one patient) and negative localization studies for insulinoma, but positive calcium stimulation tests and nesidioblastosis in the gradient-guided resected pancreas. Immunohistological studies of the resected pancreatic tissues revealed neither an increased rate of proliferation of ,-cells nor an abnormal synthesis and/or processing of either proinsulin or amylin. Evidence of overexpression of the two pancreatic differentiation factors, PDX-1 and Nkx-6·1, as well as the calcium sensing receptor (CaSR) was absent. Nevertheless, abnormal expression of islet neogenesis-associated protein (INGAP), a human cytokine expressed only in the presence of islet neogenesis, in ducts and/or islets, was identified in three of the five patients studied. All of the six patients who received a surgical operation were relieved of further neuroglycopaenic attacks, but one patient who received a subtotal pancreatectomy developed diabetes. In the remaining four patients who received diazoxide treatment, hypoglycaemic episodes were satisfactorily controlled with an attenuated response of ,-cell peptides to meal stimulation. Conclusions, Our results strengthen the existence of this unique clinical hypoglycaemic syndrome from ,-cell hyperfunction as well as the value of the selective arterial calcium stimulation test in its correct diagnosis and localization. The mechanisms underlying ,-cell hyperfunction and release of insulin to calcium, however, remain poorly characterized. Nevertheless, in a subset of patients with NIPHS, there exists some, as yet undefined, pancreatic humoral/paracrine factor(s) other than proinsulin, amylin, PDX-1, Nkx-6·1 and possibly glucagon-like peptide-1 (GLP-1) that are capable of inducing the INGAP gene and, if activated, will initiate ductal proliferation and islet neogenesis. As for the treatment, we recommend that diazoxide be tried first in each patient and, should it fail, a gradient-guided subtotal or distal pancreatectomy be attempted. [source] | ||||||||||