Tissue systems

Two studies have used single cells to study the effect of phenolic acids on mineral absorption. In sterile cell cultures of Paul s Scarlet rose, 100 pM ferulic acid inhibited Rb+ absorption in about 10 min when the cells were 4-5 days old (37). Uptake from 0.2 mM RbCl was inhibited about 25% and absorption from 5.0 mM RbCl was inhibited 45%. Absorption by 10-day-old cells was affected little. Salicylic acid at 10 pM inhibited PO - absorption by Scenedesmus, a unicellular green alga (38). These studies show that allelochemicals inhibit mineral absorption in cellular systems as well as tissue systems (Table I). 

Immediate destruction of lung tissue Systemic blood poisoning... 

Insulin resistance (IR) was originally defined by Berson and Yalow (quoted in ) as a state (of a cell, tissue, system or body) in which greater than normal amounts of insulin are required to elicit a quantitatively normal response. It is said to be present when the ability of insulin to stimulate the uptake and disposal of glucose... 

However, it has been found in two hard tissue systems that protein-polysaccharide-rich regions are mineralized to a higher degree than collagen-rich regions493). 

Civiale, C., et al. 2004. Ocular permeability screening of dexamethasone esters through combined cellular and tissue systems. J Ocul Pharmacol Ther 20 75. 

There also have been clear indications that interactions of ethylene with auxins, cytokinins, gibberellins and ABA are involved in both ethylene production and action. Generally the effects of ethylene tend to antagonize those of auxins, cytokinins and gibberellins, and tend to reinforce those of ABA, depending, however, on tissue systems involved. Reinforcement of ethylene by ABA and vice versa occurs more frequently in senescence. 

The root apex is covered with a calyptra extending proximally up to about 600 pm from the tip. The apical meristem is of the closed type, with each of the three root tissue systems, i.e. the vascular cylinder, the cortex, and the calyptra/epidermis, arising from its own independent groups of initials.16 Cellular differentiation had already started at a distance of about 600 pm from the tip in the 16 h-control while very little differentiation could be seen in roots from treated seeds. 

Micelles and Pseudocells. The characteristics and properties of coacervate drops have suggested to us the possibility of using them as "pseudocells" to uniquely restructure foods. Our concept is that coacervate "pseudocells" may be built up into simulated tissue systems through interaction between coacervate drops. 

These simulated tissue-like structures might then be used to restructure macerated fruit or vegetable tissue. The use of proteins to form coacervates for restructuring macerated plant tissue would increase the total dietary protein intake from plant sources since protein would be added to plant tissue systems. 

Mature enamel is a cell-free tissue while cementum though minerahzed is avascular, similar to some bone tissues, and may have developed to serve the local needs, not a primitive, but a derived and modulated tissue system (Poole, 1967). The bulk of the mineralized tooth is dentine, also a vital tissue that contains passageways known as tubules that are intermineralized with apatite. The tubules reach from the pulp cavity with its supply of nerves and blood vessels that enter at the base of the root(s) and extend to the enamel. Dentine has the possibility to repair itself. 

Structurally and histologically, the liver can be divided into four tissue systems (i.) intrahepatic vascular system, (2.) stroma, (3.) sinusoidal cells, and (4.) hepatocytes. 

Figure 3A. The location and manufacture of wood cells in an oak tree cross section illustrating various tissue systems. (Reproduced from Ref 39. Copyri t 1982, American Chemical Society.)...

In general, the surfactant properties of these chemicals tend to make in vitro testing difficult both qualitatively and quantitatively. The physical characteristics of surfactants tend to keep the molecule at the water/oil, water/air interface thus making meaningful contact with the in vitro organ/tissue systems difficult. Both mechanistic-related effects and noneffects, can result from attempts to test these chemicals in in vitro aqueous systems hence caution is advised when attempting to conduct, evaluate, or interpret such information. 

Biomarkers of early biological effects and damage can be measured at several levels of biological organization, i.e. the molecular, cellular, tissue, systemic and individual levels. Biomarkers should be selected for their usefulness in evaluating the health of an individual and designed to permit preventive measures with respect to population status and maintenance of biodiversity. Indeed, they should... 

Connell DW, Braddock RD, Mani SV. 1993. Prediction ofthe partition coefficient of lipophilic compounds in the air-mammal tissue system. Sci Total Environ (Su) 1383-1396. 

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