In the literature several works are available showing the chemical and physical effect of pentosan addition but it is still matter of discussion of their effect on the mechanical properties of dough. Therefore, the main objective is to further study this point, evaluating the effect of pentosans on the rheological properties of dough, using fundamental measurements and theological modelling. Small amplitude oscillations at different temperatures were performed to evaluate material
properties and stress relaxation tests, either within or out of the linear range, were used to investigate the effect of large deformations on material structure. Results showed that the effect of the addition is variable, depending on the amount, type of pentosans and deformation amplitude. The obtained https://www.selleckchem.com/products/bb-94.html results, together with rheological modelling, allow either to design dough having controlled properties during critical manufacturing steps (e.g. leavening or baking) or to reduce mechanical properties variability as effect of natural variation in flour characteristics. (C) 2010 Elsevier Ltd. All
rights reserved.”
“Background: Both neurotrophins and chemorepellents H 89 are involved in the elongation and sprouting of itch-associated C-fibers in the skin. Nerve growth factor (NGF) and semaphorin 3A (Sema3A) are representatives of these two types of axon-guidance factors, respectively.
Objective: We investigated the effects of calcium concentration and histamine on the expression of NGF and Sema3A in normal human epidermal keratinocytes (NHEK) and normal human fibroblasts (NHFb).
Methods: NHEK and NHFb were cultured under different calcium concentrations (0.15-0.9 mM) with or without histamine, and the expression of mRNA for NGF and SEMA3A was assessed by real-time PCR analysis. An immunohistochemical study was performed for Sema3A using normal skin and skin cancer specimens.
Results: In NHEK, SEMA3A expression
was elevated by high calcium concentration and reduced by low calcium condition, while NGF expression was not dependent on calcium. Their expressions were unchanged by calcium in NHFb. Immunohistochemically, keratinocytes in the prickle selleck compound layer of normal epidermis and squamous cell carcinoma cells were positive for Sema3A, sparing basal cells and suprabasal cells. The addition of histamine to NHEK at 10 mu g/ml enhanced SEMA3A expression but depressed NGF expression. In NHFb, however, histamine decreased both NGF and SEMA3A levels.
Conclusions: Sema3A inhibits C-fiber elongation/sprouting in the upper layers of the epidermis, where calcium concentration is high, thereby determining the nerve endings. Histamine reduces Sema3A production by fibroblasts, allowing C-fibers to elongate in the dermis. In contrast, the histamine-augmented keratinocyte production of Sema3A might suppress C-fiber elongation and exaggerated pruritus. (C) 2010 Japanese Society for Investigative Dermatology.