Skin inflammation structure

Some of the most important physiological steroids are the adrenocortical hormones, synthesized by the adrenal cortex. Most of these hormones have either a carbonyl group or a hydroxyl group at Cl 1 of the steroid skeleton. The principal adrenocortical hormone is cortisol, used for the treatment of inflammatory diseases of the skin (psoriasis), the joints (rheumatoid arthritis), and the lungs (asthma). Figure 25-10 compares the structure of natural cortisol with two synthetic corticoids fluocinolone acetonide, a fluori-nated synthetic hormone that is more potent than cortisol for treating skin inflammation and beclomethasone, a chlorinated synthetic hormone that is more potent than cortisol for treating asthma. 

Abnormalities in lipid lamellar structure or corneodesmolysis are apparent in scaling disorders like X-linked Ichthyosis, atopic dry skin, or in winter xerosis.2,10 Susceptibility to dry skin also shows a tendency to increase with age.3 Exposure to dry environment or extreme shifts in external humidity produces important alterations in underlying skin. Dry environment stimulates epidermal hyperplasia and early markers of inflammation. Shift in external humidity induces a profound defect in... 

Chronic inflammation causes premature aging of the skin, as observed in patients with atopic dermatitis. The constant inflammatory process leads to decreased function of the skin barrier, accompanied by loss of skin moisture. Presumably, the skin of such patients contains decreased levels of HA. Alternatively, the HA may reflect that found in chronological aging, with a change in the ability to take on water of hydration with enhanced association with tissue structures and loss of extractabil-ity. Demonstration of such changes and the precise histolocalization of this decreased HA deposition would be of intrinsic interest, a study that has not been performed yet. 

After a deep peel, the body takes 4-6 weeks" to regenerate a structurally normal skin. During these 6 weeks, the skin appears very red, as the many newly formed blood vessels are showing through an incomplete, thinned and pale epidermis. Six weeks is usually the minimum time that erythema lasts after a phenol peel. After this time, inflammation may persist and the skin can still appear red for several more months. 

In many cases of eczema, the use of emollients or astringents may not be sufficient to relieve the symptoms. Topical corticosteroids may then be required to reduce the inflammation. Corticosteroids come in different potencies and the potency of the preparation chosen should be appropriate to the severity of the condition. One percent hydrocortisone cream or ointment, which is available as a pharmacy medicine is usually effective. Long-term application of topical steroids can cause damage to the skin. The aim is to use the lowest effective concentration of corticosteroid for the shortest period. However, it is preferable to use a high potency steroid for a short period rather than a low potency steroid for a longer period. This minimizes the damage to the skin structure and reduces the possibility of systemic adverse effects. (See Chapter 7 page 119 and Table 7.1 for adverse effects of corticosteroids.)... 

A comparatively small group of structurally unique guaianolide type STLs known from Thapisa species (Apiaceae/Umbelliferae) are known to inhibit with high specificity and very high affinity (low nanomolar concentrations) intracellular calcium-pumps termed sarco-endoplasmatic reticulum Ca2+ ATPases (SERCA). Thapsigargin (TG) was identified as the active principle in the roots of T. garganica [124-127] which cause severe inflammation of the skin after contact and which had been used in traditional medicine as a counter-irritant for centuries [128, 129]. 

The toxicity of nanomaterials is not well understood, and many commentators have expressed concern that the unique properties of nanomaterials maybe associated with unknown risks. Some of the concern is because of the ability of small particles to penetrate Hving tissue. There are conflicting study conclusions on whether inhaled nanoparticles may mimic the action of asbestos in the lungs. Some studies conclude that they do cause inflammation because they can reach the lung structures that exchange oxygen and carbon dioxide from the blood. However, other studies conclude that the results are equivocal. Similarly, titanium dioxide nanoparticles have been the subject of several studies to determine whether or not they can penetrate human skin when they are used in sunscreen formulations. While studies have shown that they do not penetrate beyond the outer layer of skin, the studies have been criticized because they were aU on intact, unabraded healthy adult skin, and so the risks in actual use may not be the same as indicated by those studies. In addition, many formulations contain moisturizers that are designed to penetrate skin, and the effects of these moisturizers on the skin penetration of titanium dioxide nanoparticles are unknown. ... 

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