Invasive techniques

Griffiths-Johnson, D.A. and Karol, M.H., Validation of a non-invasive technique to assess development of airway hyperreactivity in an animal model of immunologic pulmonary hypersensitivity, Toxicology, 65, 283, 1991. 

In summary, chemiluminescence is a sensitive, non-invasive technique that can measure reactive oxidant production by small numbers of neutrophils indeed, neutrophil-derived chemiluminescence can be detected in as little as 5 fA of unfractionated human blood. The assay is suitable for automation using either multichannel luminometers or luminescence microtitre plate readers. Many researchers, however, have questioned the usefulness of this technique because of the uncertainty of the nature of the oxidant(s) that are detected. Nevertheless, in view of the recent developments made towards the identification of the oxidants measured and the assay s ability to detect intracellular oxidant production, it is has an important place in the phagocyte research laboratory. 

Disulfoton induced the liver MFO system in animals (Stevens et al. 1973). In the same study, exposure to disulfoton orally for 3 days also increased ethylmorphine N-demethylase and NADPH oxidase activities, but had no effect on NADPH cytochrome c reductase. Thus, the induction of the MFO system required repeated dosing with relatively high doses. Furthermore, these changes are not specific for disulfoton exposure, and these subtle liver effects require invasive techniques in humans to obtain liver tissue for performance of these enzyme assays. 

Spectrometer can measure the amount of glycogen from the content of C-labelled glucose in glycogen in Uver or muscle of a volunteer (for description of isotopes, see Appendix 2.2). This is a non-invasive technique, but it gives similar results to the biopsy method (Chapter 16) (Appendix 2.3). 

Applicable to invasive (for example when the patient is already catheterized) or non-invasive techniques. 

Detailed description of a porous microstructure is an essential prerequisite for unveiling the influence of pore morphology on the underlying two-phase behavior. This can be achieved either by 3-D volume imaging or by constructing a digital microstructure based on stochastic reconstruction models. Non-invasive techniques, such as X-ray micro-tomography, are the popular methods for 3-D... 

In order to reduce the technical expenditure of processing, the use of pumps for the transport of process fluids should be avoided, and such transport should be simply based on peristalsis or gravity feed, hence eliminating moving parts. For product analysis, sophisticated non-invasive techniques are proposed. 

Serup, J. A double-blind comparison of two creams containing urea as the active ingredient. Assessment of efficacy and side-effects by non-invasive techniques and a clinical scoring scheme. Acta Derm. Venereol. (Stockh.) 1992 177 (Suppl.) 34-43. 

---