Experiments with highly uptake

It should be kept in mind that high lipid concentrations and/or long incubation times may be toxic for cells and mimic results seen with reduced uptake. Therefore, all experiments need to be accompanied by viability assays, for... 

A realistic boundary condition must account for the solubility of the gas in the mucus layer. Because ambient and most experimental concentrations of pollutant gases are very low, Henry s law (y Hx) can be used to relate the gas- and liquid-phase concentrations of the pollutant gas at equilibrium. Here y is the partial pressure of the pollutant in the gas phase expressed as a mole fraction at a total pressure of 1 atm x is the mole fraction of absorbed gas in the liquid and H is the Henry s law constant. Gases with high solubilities have low H value. When experimental data for solubility in lung fluid are unavailable, the Henry s law constant for the gas in water at 37 C can be used (see Table 7-1). Gas-absorption experiments in airway models lined with water-saturated filter paper gave results for the general sites of uptake of sulfur dioxide... 

The utility of [TcOCU] in Tc chemistry is demonstrated by the first synthesis of 8-hydroxy-quinoline (8-Hox, (126)) complexes of technetium in 1984. Ligand (126) is usually one of the first choices to explore the coordination chemistry of an element, but it was as late as 1984 when the first complex with Tc was prepared. It was known that the reaction of [ Tc04] with 8-Hox leads to complexes with high brain uptake, and it was therefore important to define the structure of the active species. This sequence of events is very typical for technetium chemistry. Nuclear medicinal experiments indentify a Tc species with useful biological behavior, which prompts investigations into the basic coordination chemistry to identify the structure of the Tc... 

This is a procedure increasingly used to introduce DNA into cells and various methods are available. I have experience with the calcium phosphate technique which is described below but other techniques are described by Gorman (1985) and Spandidos and Wilkie (1984). For example, Bethesda Research Ltd. supply liposomes which will mediate the uptake of nucleic acids at high efficiency (Feigner and Ringold, 1989) and with practice and the appropriate apparatus material may be injected directly into cells (Ansorge and Pepperkok, 1988). Electroporation is particularly useful for introducing DNA into plant spheroplasts. 

The influx of vanadate is a rapid (t1/2 = 57 s at 0°C), monophasic process85, but the rate of vanadate influx approaches a saturation limit at high concentrations of exogenous vanadate. Influx experiments with added EDTA (ethylenediamminetetraacetic acid) were carried out to eliminate exchange or adhesion of vanadate to the cell surface to account for the reduction of radiovanadium in the extracellular medium. The amount of vanadium accumulated in a typical influx experiment was independent of added EDTA, and raised the intracellular concentration by 2.5 mM. Therefore, there is a net uptake of vanadium into the intracellular volume of the vanadocytes in these experiments. 

The uptake of some brominated benzenes and polybrominated biphenyls in fish (Atlantic salmon) was investigated in 1976 for the first time in a static test by Zitko and Hutzinger [250]. After 96 hours, they found no uptake of hexabro-mobenzene (HBB) from water or food in Salmo salar. The fish contained 2.3% hexane-extractable fat. The polybrominated biphenyls were accumulated to a lower extent than the polychlorinated biphenyls. Zitko and Hutzinger [250] suggested that HBB with a high molecular weight of 552 can not be taken up by fish. They concluded also that it is possible that HBB can be taken up by fish but that this compound may be converted into a non-extractable form in fish. Experiments with C-labeled HBB are required to determine its fate. But as far as we know, no bio concentration experiments with C-labeled HBB and fish were conducted. 

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