Diffusion tumors

T4 Locally advanced, technically unresectable tumor (each ipsilateral pleural surface) At ieast one of the following (a) diffuse tumor extension or multiple tumor foci in the chest wall with or without associated rib destruction, (b) direct transdiaphragmatic extension to the peritoneum, (c) direct extension to the mediastinal organs, (e) direct extension to the spine, or (f) extension to the internal surface of the pericardium with or without pericardial effusion or involvement of the myocardium... 

Robert Langer, Polymer Systems for Controlled Release of Macromolecules, Immobilized Enzyme Medical Bioreactors, and Tissue Engineering J. J. Linderman, P. A. Mahama, K. E. Forsten, and D, A. Lauffenburger, Diffusion and Probability in Receptor Binding and Signaling Rakesh K. Jain, Transport Phenomena in Tumors... 

B2 Diffuse involvement of whole gland, T2 (Tumor confined within the prostatec)... 

There are certain histologic subtypes of diffuse, aggressive NHL that respond less well to treatment with conventional regimens such as CHOP. Burkitt s lymphoma, lymphoblastic lymphoma, mantel cell lymphoma, and primary CNS lymphoma are examples of disease that benefit from more intensive therapy. Regimens such as hyper-CVAD, which alternate cycles of hyperfractionated cyclophosphamide, doxorubicin, vincristine, and dexamethasone with high-dose cytarabine and methotrexate, often are substituted for CHOP. Intrathecal therapy with methotrexate is indicated with documented CNS infiltration of tumor or involvement of the sinuses. The recent appreciation of the etiology of Helicobacter pylori in the etiology of peptic ulcer disease and the association between colonization and mucosal-associated lymphoma (MALT) has spurred... 

The convective diffusion equations presented above have been used to model tablet dissolution in flowing fluids and the penetration of targeted macro-molecular drugs into solid tumors [5], In comparison with the nonequilibrium thermodynamics approach described below, the convective diffusion equations have the advantage of theoretical rigor. However, their mathematical complexity dictates a numerical solution in all but the simplest cases. 

Analysis of drug transport in a solid tumor compartment could be represented in spherical coordinates as well as cylindrical [19] as depicted in Eq. (56). In this case, and assuming that drug diffusion occurs only in the radial direction, Eq. (53) can be written as... 

Various optical detection methods have been used to measure pH in vivo. Fluorescence ratio imaging microscopy using an inverted microscope was used to determine intracellular pH in tumor cells [5], NMR spectroscopy was used to continuously monitor temperature-induced pH changes in fish to study the role of intracellular pH in the maintenance of protein function [27], Additionally, NMR spectroscopy was used to map in-vivo extracellular pH in rat brain gliomas [3], Electron spin resonance (ESR), which is operated at a lower resonance, has been adapted for in-vivo pH measurements because it provides a sufficient RF penetration for deep body organs [28], The non-destructive determination of tissue pH using near-infrared diffuse reflectance spectroscopy (NIRS) has been employed for pH measurements in the muscle during... 

Fig. 18. (a) Representation of the tumor hypoxic state (diagram adapted from Ref. (83a). Arrow direction indicates decrease in pC>2 (< 1 mmHg), achieved for tumor depths larger than 100 pm (b) proposed mechanism for redox-mediated retention of [Cu(ATSM)] in hypoxic cells (101-105). Note Contrary to common belief cell membrane crossing solely by direct diffusion is unlikely for compounds of this family is unlikely, as indicated by fluorescence imaging work on aromatic Zn(II) analogs (vide infra). Endocytosis is the more likely uptake mechanism (112-113). 

In this situation, the tumor cells (or a group of cells viz. microtumor) are the immobile phase and the electroosmotic flow causes the water to move as a plug, the entire velocity gradient being concentrated at the cell surface in a layer of the same order of thickness as the diffuse double layer (Figure 5). In concentrated solutions, the thickness of the diffuse double is quite small (< 10 A) whereas in very dilute solutions (as are indeed... 

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