Skin chemical

In a number of species, the active predator odors originate on the dorsal skin. Neonate pygmy rattlesnakes, Sistrurus miliarius, and timber rattlesnakes, C. horridus, respond to dorsal skin chemicals of the ophiophagous king snakes and indigo snakes, Drymarchon corais, but not to those from ventral skin or skin... 

Lizards that prey on snakes hut are also eaten hy larger snakes discriminate skin chemicals of snakes very well. Monitor lizards, Varanus albigularis, fall in this group. Hatchling monitors attacked harmless snakes but avoided venomous species. However, they accepted meat of all snakes if carefully skinned. The hatchlings tongue flicked to invertebrate prey covered with skin from venomous snakes and rejected these samples (Phillips and Alberts, 1992). 

Regarding the physical properties of acids, they taste sour and leave a burning sensation on one s skin. Chemically, they are corrosive and lose their physical properties when in contact with basic solutions. In solution, they produce an excess of hydrogen or hydronium ions. Regarding physical properties of bases, they taste bitter and feel slippery. Chemically, they react with acids to form salts and water. In solution, they produce an excess of hydroxide ion. The whiting compounds produce excess hydroxide ions in solution. 

The presumed simplicity of in vitro penetration assays has led to their universal acceptance for preclinical and other screening purposes. However, they do not mimic human exposure in some important areas. Excised skin must often be stored prior to us and thus retains only some enzymatic activity. In intact skin, chemical penetrating the epidermis would enter the circulation through vessels and lymphatics located just below the epidermis. In excised full-thickness skin, the dermis is also involved in absorptive process. Storage conditions and procedures for preparing the tissue may affect skin absorption and metabolism. This is no opportunity to qualify key aspects of penetration cell turnover and desquamation and rub off. 

If a cytotoxic chemical is capable of being absorbed across the stratum corneum barrier, it has the potential to cause toxicity to the skin. Chemical-induced damage... 

Hall, A.H., Blomet, J., Mathieu, L. (2002). Diphoterine for emergent eye/skin chemical splash decontamination a review. Vet. Hum. Toxicol. 44 228-31. 

Photoallergic responses to sunscreen products represent an area where chemical components not known to produce dermal allergic responses are activated by solar radiation to produce ACD. I45 46 It is hypothesized here that in these instances, electromagnetic radiation may activate the skin to adsorb and/or absorb species that do not so react without the incident radiation. Alternatively, the molecular species themselves are excited by the radiation to molecular states that make them more reactive to skin. Chemicals exhibiting photoallergic contact dermatitis include oxybenzone, butyl methoxy dibenzoylmethane, methoxycinnamate, and benzophenone—all molecules that are readily photoexcitedJ45 ... 

ETCA helps combat acne lesions by exfoliating the skin chemically and through use of the post-peel mask cream. Daily care helps maintain the results of dermatological or systemic acne treatments. No peel can change the genetic... 

Exposure to low concentrations may not produce immediate effects. However, the severity of poisoning is not related to the presentation or magnitude of immediate symptoms. Symptoms may include eye and airway irritation, tearing, shortness of breath, coughing, wheezing, chest tightness, and delayed pulmonary edema. If halogens have been released, there may be redness of the skin, chemical bums or even thermal burns. 

HUMAN HEALTH RISKS Acute Risks demiatitis burns coughing laryngitis headaches nausea destructive to mucous membranes, upper respiratory tract, eyes and skin chemical pneumonitis pulmonary edema Chronic Risks chronic bronchitis tumors cancer. 

Exposure Routes, Symptoms, Target Organs (see Table 5) ER Inh, Ing, Con SY Irrit eyes, nose, throat dizz, drow, head, nau dry cracked skin chemical pneu (aspir liquid) TO Eyes, skin, resp sys, CNS First Aid (see Table 6) Eye Irr immed Skin Soap wash prompt Breath Resp support Swallow Medical attention immed ... 

Agarwal, R. and Mukhtar, H., Oxidative stress in skin chemical carcinogenesis, in Oxidative Stress in Dermatology, Fuchs, J. and Packer, L., Eds., Marcel Dekker, New York, 1993, pp. 207-241. 

In this chapter, we introduce a novel system coefficient approach developed in our research center. The system coefficient approach uses a set of probe compoimds to measure the molecular interaction strengths of a skin/chemical mixture system. A linear free-energy relationship (LEER, a thermodynamic principle) is used to dissect the complicated molecular interactions in the absorption system into basic molecular interaction forces, which can be parameterized and used to predict a free-energy-related property of the system, such as partition coefficients or permeability. In the system coefficient approach, a chemical mixture is treated as a medium composed of the major components and other minor or trace components. A set of system coefficients represents the relative molecular interaction strengths of the chemical mixture, and a set of solute descriptors represents the molecular interaction strengths of a chemical. A free-energy-related specific property is interactively correlated to the system coefficients of the chemical mixture and the solute descriptors of the chemicals, which can be used to provide quantitative predictions... 

The Systran coefficient approach uses a set of probe compounds to detect the molecular intraaction strengths of the skin/chemical mixture system. The selection of the probe compounds is a critical step in developmrait of the system coefficient approach. 

Katayama, K., Takahashi, O., Matsui, R., Morigaki, S., Aiba, T., Kakemi, M., and Koizumi, T. (1992). Effect of 1-menthol on the permeation of indomethacin, mannitol and cortisone through excised hairless mouse skin. Chemical and Pharmaceutical Bulletin (Tokyo), 40 3097-3099. 

Electrolytic effects are related to DC, applied or rectified by nonlinear effects at the electrodes or in the tissue. Also with very low-frequency AC (e.g., <10 Hz), each half period may last so long as to cause considerable nonreversible electrolytic effects. With large quantities of electricity (Q = It) passed, the electrolytic effects may be systemic and dangerous (lightning and high-voltage accidents). The risk of skin chemical bums is greater under the cathode (alkali formation) than the anode (acid formation), the natural skin pH is on the acidic side (pH < 5.5). 

The rate of absorption is influenced by the status of the skin, chemical structure of the steroid and such other factors as formulation and formulation vehicle. Topical corticoids applied to diseased skin will be absorbed to some degree into the systemic circulation. When administration is chronic or when large areas of skin are involved, the absorption may be sufficient to cause systemic effects including cushinoid changes and adrenocortical suppression. 

Due to the wide diversity of the substances that might be involved, it is important to better understand the deep mechanisms of the chemical reactivity of irritants and corrosives on the skin. This helps to optimize the management of skin chemical splashes. Besides, we have learned, by experience, that the rapidity and efficiency of fhe emergency decontamination are decisive parameters in order to prevent the development of potentially severe lesions and aftereffects due to the chemical skin lesions. 

The different skin layers have been described in detail in Sect. 2.1. In this part, we will discuss the constituents of the skin layers in order to point out which are the biological and biochemical targets of aggressive chemicals. For us, everything is naturally molecular chemistry in an ultrastruc-tural scale. This mechanistic and materialistic approach might surprise. Nevertheless, not only this molecular organization of the living substance is real, but it even helps to understand the intimacy of the skin chemical hazard and the ultimate consequences of chemical injury. 

In an optimal way, an effective capture and a definitive neutralization of the corrosive within the 10 s following the contact guarantee the absence of lesions. By intervening within the first minute, the skin chemical injury shall be avoided or minimized. Beyond this first minnte, the lesions gradually and inexorably settle down. This does not mean that intervention is not worth trying and will give some benefit This is what is demonstrated in the study of a clinical case of chemical injuries with late care [5],... 

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