Substance cells

Cultured cells (from human peripheral blood lymphocytes or from Syrian hamster embryo (SHE)) or cell lines (CHO, V79, CHL/IU, L5178 Y) are exposed to the test substances both with and without an exogenous source of metabolic activation unless primary cells with metabolizing capability are used. After exposure to the test substance, cell cultures are grown for a sufficient period to... 

Pfeiffer, W., The distribution of fright reaction and alarm substance cells in fishes, Copeia, 1977, 653. 

Changes in particle surface structure by chemical modification provide increased selectivity in the interaction with certain biostructures and affinity to specific substances, cells or microorganisms, e.g. Proteus mirabilis (Figure 13). However, Silics particles affect the mobility of these microorganisms more... 

Space Measured Test Substance cells cells... 

CNS implants of encapsulated genetically engineered cells producing therapeutic substances Cells for facilitating crossing of the blood-brain barrier Gene transfer... 

But the different degradation processes, PHB catalyzed by enzymes and acid-base catalyst and PLA just by acid-base catalyst, determine to a considerable extent the degradation and/or resorption times of both materials and therefore the areas for human and veterinary medical use. These materials are used in human or veterinary medicine, or they are presently being tested in the in vitro phase, for example, as resorbable sutures, for blood vessel repair, drug-delivery systems, bandages, scaffolds for producing retard materials for coupling active substances, cells and... 

The relation of heparin to inflammation is discussed, as are its relation to ground substance, cells, pinocytosis, and biologic ion exchange. 

Chivers DP, Wisenden BD, Hindman CJ, Michalak TA, Kusch RC, Kaminskyj SGW, Jack KL, Ferrari MCO, Pollock RJ, Halbgewachs CF, Pollock MS, Alemadi S, James CT, Savaloja RK, Goater CP, Corwin A, Mirza RS, Kiesecker JM, Brown GE, Adrian JC Jr, Krone PH, Blaustein AR, Mathis A (2007) Epidermal alarm substance cells of fishes are maintained by non-alarm functions possible defence against pathogens, parasites and UVB radiation. Proc Biol Sci 274 2611-2620... 

Fig. 10.11 The uptake of benzoic acid (pi 4.2) by baker s yeast at various pH values. The uptake is inversely proportional to the percentage ionized. (A) Ratio of distribution of total substance (cell/fluid). (B) Percentage ionization. (Bosund, 1960.)...

Wisenden, B. D., and Smith, R. J. F., 1997, The effect of physical condition and shoalmate familiarity on proliferation of alarm substance cells in the epidermis of fathead minnows, J. Fish. Biol. 50 799-808. 

Pfeiffer, W., 1977, The distribution of flight reaction and alarm substance cells in fishes, Copeia 1977(4) 653. Schutz, F., 1956, Vergleichende Untersuchungen ilber die Schreckreaction bei Fischen und deren Verbreitung,... 

In most families of the Superorder Ostariophysi (e.g., minnows, suckers, catfish, characins and loaches), individuals show antipredator responses when they detect chemicals released from injured conspecifics. This response is absent in some armoured catfish, pencilfishes and ostariophysans with electric organs (Pfeiffer 1977). In ostariophysan fishes the alarm pheromone is contained in epidermal club cells, or alarm substance cells, that have no pores to the exterior, and have no proven function except the production and storage of the alarm substance that triggers antipredator behavior in conspecific receivers. 

Bernstein, J.W. Smith, R.J.F. 1983. Alarm substance cells in fathead minnows do not affect the feeding preference of rainbow trout. Env. Biol. Fish., 9, 307—311. 

Smith, R.J.F. 1973. Testosterone eliminates alarm substance cells in male fathead minnows (Pimephales promelas). Can. J. Zool, 51, 875-876. 

Two analogous chemical alarm systems have been described in fishes and there is evidence that other comparable systems exist. I will deal primarily with the best known of these systems, the alarm substance or Schreckstoff system found in the ostariophysan fishes (e.g. minnows, suckers, catfish), first described by von Frisch (1938) and recently reviewed by Pfeiffer (1977, 1982) and Smith (1977, 1982a). The terms "alarm substance" and "alarm substance cells" (ASCs) will be used only for the ostariophysan system. The second established alarm system is found in darters of the Family Percidae (Smith, 1979, 1982b). The darter system will be specifically designated when it is described. 

The skin of two groups of fish that show alarm responses to skin extract. (A) The skin of an ostariophysan fish, the bluehead chub (Nocomis leptocephalus), illustrating the alarm substance cells (ASCs) in the epidermis (b)... 

Legend ASC=alarm substance cell, D=dermis, E=epidermis, M-=muscle, Me=melanophores, Mu=mucus cells, Sa=sacciform cells. 

The evolution of alarm substance cells might not be driven exclusively... 

Smith, J. D., 1982, The control of alarm substance cells in some minnows, M.Sc. Thesis, Biology Dept., University of Saskatchewan,... 

Determination of [ H]-AA release. Aliquots (1 ml) of [ H]-AA-prelabelled U937 cells were placed in sterile 8 ml polystyrene tubes (Falcon) and test substances dissolved in cold serum-free RPMI were added at graduated concentrations. Control cells received an appropriate volume of RPMI without test substances. Cell cultures were kept for 1 hr at 4°C, after which the temperature was raised to 37°C. The cells were further incubated for 1 hr (dose-response relationship). After incubation, [ H]-AA was determined in the 200 g supernatants of cultures by liquid scintillation counting (liquid scintillation counter, Wallac 1410, Wallac Oy, Turku, Finland). Three experiments were carried out in every given series. All assays were performed in triplicate. 

The viability of the living cells in the model must be high enough to discriminate properly between the positive and negative control substances. Cell viability is measured by the amount of MTT reduction water-soluble yellow dye is converted to insoluble purple-coloured formazan within cells. This technique has been shown to give accurate and reproducible results in various laboratories. The skin disc, after treatment with the material test, is placed in an MTT solution of 0.3 mg/ml at 20-28 °C for 3 h. The precipitated blue formazan product is then extracted (solvent extraction) and the concentration of the formazan is measured with a wavelength of between 545 and 595 nm. 

A) Ratio of distribution of total substance (cell/fluid). (B) Percentage ionization. (Bosund, i960.)... 

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