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Characteristics of the skin and body connection to the environment (03/13/2010)
(...) Modern cosmetology has the task of interacting with physiology in maintaining its good condition. Macroscopic Characteristics The skin is the largest, most extensive organ of our body. In fact, the average adult has about 170-200 square cm of skin with a weight that varies between 15 kg and 17 kg (obviously varying according to the subject's height and dimensions). (...)

What is the epidermis and what is it made of (03/13/2010)
(...) This mechanism is defined as epidermal cell turnover and is the basis of the continuous and incessant renewal of the epidermis. Under the microscope the epidermis is an obvious superimposition of cell layers, each clearly different from the others, these being the maturing phases of the keratinocytes. The basal layer is composed of a single line of more or less cylindrical cells that are densely packed and adherent to the basal membrane. (...)

Differences between the structure of head hair and body hair (03/13/2010)
(...) Lanugo hair The lanugo is the thin and unpigmented hair present in the foetus before and just after birth, which is subsequently transformed into terminal hair (like that of an adult). Vellus hair is that present in women, adolescents, and also on the scalp of bald individuals. All three hair types have the same structure and even the same histological profile. (...)

Percentage of hairs found in the growth phases and our health (03/13/2010)
(...) Hair breakage alopecia Dysfunctional alopecias are the most frequent forms, with both common baldness (androgenic alopecia) and temporary hair loss (telogen effluvium) belonging to this category. The latter condition very often occurs after giving birth. Destructive alopecias are those conditions of the scalp that may be either congenital or acquired. (...)

Sweat glands functions and their importance for health (03/13/2010)
(...) Therefore, strictly speaking, they should not be classified as sweat glands. Eccrine Sweat Glands Eccrine sweat glands are merocrinous glands in that they produce an aqueous solution of low density that does not appreciably cause disintegration of the epithelial cells. Their principle function is that of thermoregulation: sweating to allow the body to rid itself of excessive heat. (...)

Keratin filaments and basic protein containing histidine (03/13/2010)
(...) Of these intermediate filaments the most important examples are vimentin, present in the mesenchymal cells, GFAP acidic protein, which composes the glial filaments of the glial cells, the neurofilaments present in the neurones, desmin of the muscle cells, and the proteins of and the nuclear matrix, nuclear laminins A,B,C. The polypeptide structures of all the intermediate filaments have a similar skeletal part composed of structural blocks of polypeptide subunits. The number of subunits varies between 1 and 30. (...)

The seven basic functions of human skin (03/13/2010)
(...) Finally, the skin plays the essential role of mechanical protection that we all appreciate every day when large or small mechanical traumas are cushioned by our skin. Immunological Function The first site of entry for foreign substances and bacteria is the skin. With the Langerhan cells the skin is able to identify these and to prepare a defence. (...)

Change in the extracellular portion of the receptor (12/19/2009)
(...) The rise in intracellular Ca culminates in the extrusion of GH-containing secretory granules. GH secretagogues bind to a separate G-protein-coupled receptor only recently identified. This receptor is linked through the heterotrimeric Gj protein to phospholipase C, resulting in phosphoinositol hydrolysis and stimulation of protein kinase C. (...)

Enhancement of hormone release (12/18/2009)
(...) By contrast, studies questioning GHS putative influence on SRIH neurons are far less conclusive. Indeed, no change in SRIH release into HPB has been observed in both studies performed in sheep. GHS receptor expression was either barely or not detectable in neurons of the periventricular nucleus, the major source of SRIH released into HPB and no increase in Fos immunoreactivity was detected in these neurons following GHRP-6 injection. (...)

Growth hormone secretion is pulsatile in mammals (12/18/2009)
(...) Bowers et al. observed a 2-foId rise in serum Cortisol and prolactin levels after i.v. (...)

Endocrine pathway controlling secretions (12/16/2009)
(...) For many years it was thought that the pulsatile secretion of GH by the pituitary somatotrophs was controlled by only two antagonistic hypothalamic peptides: somatostatin which inhibits GH release and GHRH which stimulates GH release. Both peptides had been purified and well characterized, while their specific receptors have been cloned. Both GHRH and somatostatin receptors belong to the family of seven transmembrane receptors coupled to a heterotrimeric GTP-binding protein. (...)

Synergistic actions of growth hormones (12/16/2009)
(...) These results forecast the important accomplishment of the cloning of the G protein 7 transmembrane coupled receptor of GHRP. Subsequently, direct in vitro evidence has been obtained by Adams and Wu that GHRP acts via the phospholipase-C pathway, however, crosstalk does occur between the GHRP and GHRH pathways. Results show more direct evidence for the existence of the putative GHRPlike hormone in porcine hypothalami. (...)

Effects on efficacy endpoints (12/16/2009)
(...) Given the persistence and thus long-lasting activity of this molecule it was always possible that this molecule may not have long lasting efficacy in humans. This possibiUty was recently confirmed when MK-677 failed to show a maintained acceleration of statural growth in children. A synergistic interaction between administered GRF and GHRP occurs in vivo, but apart from one study, such synergism has not been seen in vitro. (...)

Biochemical breakthrough in the cloning protocol (12/16/2009)
(...) MK-0677 responsiveness was dependent on the co-injection of the G family member Gi. Other G subunit tested failed to rescue MK-0677-induced bioluminescence. This observation provided a key biochemical breakthrough in our expression cloning protocol by enhancing assay sensitivity and reproducibility. (...)

Functional activation of cloned cells (12/16/2009)
(...) Binding is saturable, of high affinity, identifying two classes of binding sites when expressed in heterologous cells. The identification of two classes of binding sites is most likely due to an excess of uncoupled receptors over available G proteins, leading to the presence of high and low affinity state GHS-Rs, as often observed when cloned receptors are overexpressed. This assertion is supported by the observation that only -50% of the binding can be blocked by GTPyS. (...)

Significant species difference exists between sheep and rat (12/16/2009)
(...) Thus, in sheep cells at least, GHRP-2 activates adenylyl cyclase leading to an increase in cAMP levels and activation of cAMP-dependent protein kinase A (PKA). Thus, PKA could phosphorylate transmembrane Ca channels to modify their properties in the manner observed by electrophysiological means. A significant species difference appears to exist between sheep and rat somatotrophs in terms of GH release in response to GHRP-2. (...)