Ga localizing in

ACS Symposium Series American Chemical Society Washington, DC, 1980. 

A similar approach to tumor uptake mechanism has been presented (5iL) In this case, the gallium-67 is assumed to accumulate in tumor cells in an unknown manner because of Increased deposition of the radionuclide at the tumor site in an inflammatory response. Because acute inflammation is associated with increased capillary blood flow and permeability ( ) as well as capillary sprouting (86), these changes allow more Ga to be delivered to the tumor site. This simple mechanism offers the advantage of explaining why gallium accumulates only in viable (not necrotic) neoplasms (53.) and that it may operate 

The similarity between gallium and the alkaline earth elements has been developed in a different explanation for gallium tumor uptake (87.88.8bl, Because the lack of tumor specificity in uptake suggests that a simple mechanism is 

Using cultured mammalian sarcoma cells, it has been found that transferrin is necessary in the growth medium for galllum-67 uptake to occur (95,96.97). A transferrin receptor on EMT-6 sarcoma cells for 25i iabeled transferrin was characterized by Scatchard analysis to have an average association constant K = 4.54 X 10 1/mole and approximately (with variation) 500,000 receptors per cell ( ). It was proposed that tumor accumulation of galllum-67 can occur only if the metal is complexed with transferrin so that it can interact with the receptors of tumor, as well as non-mallgnant cells (.33). The complex then enters the cell via an adsorptive endocytosis process (95.96.97.98.99) similar to the manner in which iron is taken up by reticulocytes and bone marrow cells (100.101). These transferrin receptors are saturable (that is, a plot of 125i transferrin uptake versus extracellular transferrin concentration reaches a peak ( at about 200 u g/ml) as more carrier transferrin is added to the medium) (95). Since uptake is also proportional to the fraction of 

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Because of the small transition frequencies, the SSE system is very delicate. Great care has to be taken to provide a cold environment. Since the Boltzmann constant, expressed in frequency, is given by ks = 21 GHz/K, the energy gap to the continuum is bridged easily at a temperature on the order of 10 K. This means that a quasi-two-dimensional electron gas localized in fpi x) can exist only at liquid helium temperatiures. This is one of the reasons why liquid helium is a preferred dielectric for SSE experiments. 

Figure 5. An example of Ga localizing in a tumor. This is a patient with lymphoma. As observed, there are multiple areas of increased activity in the...

A system can be removed from a condition of thermodynamic equilibrium by external influence. For example, one can inject another gas into a certain point of the predominant gas and, due to thermal (chaotic) molecular movement the concentration of the second component will tend to spread over the whole volume. Sooner or later it will be equal. One can heat gas locally in one area of the volume and the gas temperature will also start to equalize over the whole volume due to molecular chaotic movement. 

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