Growth of tissues

InsuUn-like growth factors IGE-I IGF-II ICF-I is secreted by the Uver and is stimulated by growth hormone. ICF-II is most active in the foetus. They stimulate growth of tissue throughout body. 

The growth of tissue (or, more precisely, the number of cells) is actually regulated by apoptosis. In addition, apoptosis allows the elimination of unwanted or superfluous cells—e.g., during embryonic development or in the immune system. The contraction of the uterus after birth is also based on apoptosis. Diseased cells are also eliminated by apoptosis—e.g., tumor cells, virus-infected cells, and cells with irreparably damaged DNA. An everyday example of this is the peeling of the skin after sunburn. 

Tumor (neoplasm) A growth of tissue forming an abnonnal mass. Cells of a benign tumor will not spread and cause cancer. Cells of a malignant tumor can spread through the body and cause... 

In addition to classical hormones, other chemical messengers called growth factors serve to coordinate growth of tissues during development. 

Biological Roles of Zinc and Copper. Zinc and copper are essential cofactors at the active site of a number of enzymes. Zinc is a component of more than 200 proteins and enzymes (Table II). Copper, sim-lleT to iron, participates both in redox reactions and as a proton doner (Table III). The normal human adult body contains approximately 50-100 mg of copper and 2.0 g of zinc. The vast majority of tissue copper is found in the liver, kidney, heart and brain. In the blood, copper exists within the red blood cell as superoxide dlsmutase and in the serum as ceruloplasmin. Copper is a component of aerobic metabolism, bone synthesis, and erythrocyte development. Zinc is found primarily in the liver, kidney, bone and prostate. Zinc is essential for normal growth of tissues, wound repair, skin structure, reproduction, taste perception, and the prevention of dwarfism. 

Tissue culture The maintenance or growth of tissues, in vitro, in a way that may allow differentiation and preservation of their architecture and/or function. 

Mathematical models that correlate neovascularization with growth of tissue are limited in number. Liotta et al. (1977) developed a mathematical model which describes the spatial and temporal growth of vessels and cancer cells in a transplanted tumor by two coupled partial differential equations with nonlinear birth and death rate terms. While these authors made no attempt to fit their data quantitatively, their model simulates the density of tumor cells and endothelial cells qualitatively and predicts the onset of necrosis in tumors. 

The specialty field of membrane ion transport studies is growing rapidly. It is, however, not the intent of this brief discussion to do more than touch on the subject of mechanisms by which electric fields control membrane transport. Rather, emphasis has been placed on describing the effects of electric fields on cells. At present, much of the research in this experimental field is Edisonian. However, the large body of experimental data that has accumulated strongly supports the hypothesis that ionic gradients are critically involved in the control of cell processes. That this is true can best be illustrated by the practical medical uses of electric fields to control or inhibit growth of tissue and bone. 

Lateral growth of tissue many aligned cells in parallel... 

Myelopoiesis—formation of cells in the bone marrow Myocardial—pertaining to the muscular tissue of the heart Neoplasm—new growth of tissue serving no physiological function benign, potentially malignant, or malignant Nephritis—inflammation of the kidney... 

The reduction of polymer viscosity also facilitates the mixing of the polymer with an active component [156], The ability of CO2 to foam polymers provides a convenient method to prepare scaffolds for the application of tissue engineering, providing an environment able to promote the differentiation and growth of tissue. Particle formation [157] provides a route to prepare formulations with controlled release characteristics via encapsulation. The use of CO2 also provides a convenient method to deliver coatings to pharmaceutical formulations [158], A detailed discussion of polymer processing for various pharmaceutical apphca-tions has recently been published [159],... 

Bioreactor—a cell culture device developed at NASA-Johnson Space Center that brings a new scientific tool to cancer and virus testing without risking harm to patients. The rotating bioreactor wall allows three-dimensional growth of tissues without limiting pressure points. It has been successful in culturing over 35 cell types. 

The interaction of vesicles with molecules in the surrounding solution is a particularly fascinating topic. Small and large molecules can bind to the bilayer membrane and mediate the interactions between vesicles. In this respect, synthetic vesicles are versatile model systems for the protein- and carbohydrate-mediated recognition, adhesion, and fusion of membranes that occur during endocytosis, viral infection, cell adhesion, and the growth of tissue from individual cells. 

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