Dermal cells

Dermal cells/organ systems Dermal irritation... 

In skin, both epidermal (keratinocytes) and dermal cells (fibroblasts) respond to mechanical loading by undergoing structural and biochemical changes. Wang and Stamenovic (2000) have shown that fibroblasts grown... 

There are three types of tissue that make up all of these plant parts. The dermal cells are the densely-packed outer layer, which varies in thickness in different plants. The cells in this layer may secrete a waxy coating or cuticle that helps reduce the amount of water lost through a plant s exposed surfaces. The ground tissue is the body of the plant. And vascular tissue is made up of the specialized cells that transport water, minerals, food, and hormones throughout the plant Vascular cells are divided into xylem, which transport water and minerals from roots to the upper plant, and phloem, which takes food (sugars) from the leaves to the rest of the plant. These two types of cells are usually arranged in parallel, concentric form, with the phloem on the outside. 

There are two main sensitization reactions-immedi-ate and delayed hypersensitivity. Immediate type hypersensitivity is the result of antibody-allergen interaction occurring in the skin the reaction that develops is known as allergic contact urticaria. Delayed type hypersensitivity is the result of cell-mediated immunity and is the most frequently reported side effect of topical drugs. Both epidermal and dermal cells play pivotal roles in irritation and sensitization. Keratinocytes... 

The cytotoxicity of acetaminophen has been demonstrated in cultures of HeLa cells, L929 and 3T3 murine fibroblasts, chick embryo neurons, rat embryonic and skeletal muscle, peripheral blood lymphocytes, and lung and dermal cells. In addition cytotoxicity of acetaminophen has been evaluated in BF-2 fish cell line (see section on Ecotoxicology ). 

In addition to the epidermal abnormalities noted above, there is an increase in the number of dermal cells which is probably of secondaiy importance. However, it should be noted that Weddell (W7, W8) using special histochemical techniques has reported an increased production and breakdown of Schwann cells in the psoriatic lesion, and he believes that these changes are of primary importance in stimulating the epidermal lesion. Along similar lines is the suggestion by Pinkus and Mehregan (P7) that the polymorphonuclear leukocytes are of prime importance in stimulating the epidermis and that the dilated capillary in the papilla squirts these leukocytes into the epidermis as an initial event. 

Wollina U, Knoll B, Peufee K, Baeth A, Muller D and Huschenbeck J (1996) Synthetic wound dressings - evaluation of interactions with epithelial and dermal cells in vitro. Skin Pharmacol 9 35-42. 

Nanofibrous composite Morphology, mechanical Isolated fibroblast dermal cells Fibroblasts were attached on all the The electrospun Duan et al. 

Many different cell types are currently being used for in vitro studies relating to nanoparticle toxicology. Some cells are obtained as donor cells which behave similar to normal cells when in culture. Other cells are derived from immortalized lines which have infinite growth capabilities in culture. Techniques have also been apphed to construct cell cultures that mimic a specific location within the body (e.g. dermal cell, epithelial lung cells). 

Contrast the expected optimal environments for hepatic cells compared to dermal cells. 

Han, I., et al., 2007. Effect of poly(3-hydroxybutyrate-co-3-hydroxy valerate) nanofiber matrices cocultured with hair follicular epithelial and dermal cells for biological wound dressing. Artificial Organs 31 (11), 801—808. 

Gene feerapy and cell therapy have been combined to result in murine stromal cells transduced to produce Bh4P-2. The cells were seeded on a PLGA-HA matrix and found to induce heterotopic bone regeneration (Laurencin et al., 2001). Likewise, rat dermal cells were infected with a retrovirus... 

SWCNTs Immune-competent hairless SKH-1 mice 40, 80, and 160 pg/animal 5 days Oxidative stress and increased number of dermal cells 115... 

Mouse dermal cells (] imaiy) Sulfate Retinyl acetate Shapiro and Poon (1978)... 

Skin substitutes currently available vary in complexity, ranging from temporary synthetic wound dressings to permanent skin replacements, either with or without incorporation of cultured skin cells (Table 47.1). Some of the acellular materials have components that incorporate into the wound bed and may become populated with dermal cells from the host. These dermal substitutes replace the dermal component of the... 

Sensitization and Irritation ISO 10993-10 are two more test that are required under ISO 10993-1. Sensitization or hypersensitivity reactions usually occur as a result of repeated or prolonged contact with a chemical substance that interacts with the body s immune system. Because most such reactions to biomaterials have been of the dermal cell-mediated type, rather than the humoral or antigen-antibody type, the skin of laboratory animals is used in sensitivity testing. Dermal sensitization reactions are marked by redness and swelling. The guinea pig, a species known to be nearly as responsive to dermal sensitizers as human beings are used in the sensitization test. 

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