Hair chemically induced

S. Heshmati and H.l. Maibach Chemically Induced Hair Loss... 

Fig.8.4 a,b. Idear candidate for deep chemical peeling middle-aged fair-skinned woman with blue eyes and blond hair and photodamage-induced wrinkling before (a) and after (b) deep chemical peel... 

An in vitro method using hair follicle cells to investigate unscheduled DNA synthesis (UDS) has been developed. Plucked follicles were exposed to tritiated thymidine and the UDS activities were determined autoradiographically (the number of dark grains in the outer root sheath of nonperipheral cells were used to estimate UDS). Many, but not all chemicals that have been shown to induce UDS in rat liver cells also stimulated UDS in hair follicles. 

Photosensitizers are chemicals that induce photoallergic responses. These can be drugs, industrial chemicals, agricultural chemicals, and cosmetics. They include artificial sweeteners, petroleum products, deodorants, hair sprays, makeup, antibiotics, antihistamines, antifungals, cardiovascu-lars, diuretics, nonsteroidal anti-inflammatory drugs (e.g., ibuprofen), sunscreens (e.g., p-aminobenzoic acid, PABA), and various fragrances)9 ... 

Percutaneous penetration can be in excess of 50% of applied dose. In theory, percutaneous penetration of occupational chemicals could lead to sufficient body burden to lead to hair loss. Similar kinetics are possible from inhalation. Future work in the field of occupation induced hair loss will benefit by including dermatopharmecokinetic data (Bronaugh and Maibach 1991). 

C46H78N4O24S 1103.201 Prod, by Rhizobium meliloti. Active against gram-positive bacteria. Believed to be a chemical trigger involved with N fixation in legumes. Induces root hair deformations and nodule organogenesis specifically on alfalfa. Pale brown-yellow powder (as Na salt). Md -1.2 (c, 0.1 in H2O). 

Hair relaxer products can disrupt disulfide bridges from cysteine chains inducing a smoothed hair structure (See Sect. 3.3.3). There are two main kinds of chemical hair relaxers smoothing with thiol or alkaline (base) (Table 4.1). 

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