Methodological considerations

Atkinson, S.A. 1985 Characterization of the non-protein nitrogen fraction of human milk methodological considerations. In Jensen, R.G. and Neville, M.C., eds.. Human Lactation. Milk Components and Methodologies. New York, Plenum Press 39-43. 

There are important methodologic considerations which apply to the use of cultured amniotic fluid cells for the detection of biochemical disorders. The first is that the enzymes which can be sampled are those which are usually present in fibroblasts or fibroblast-like cells. Therefore, conditions such as phenylketonuria and glycogen storage disease type I, which are associated with deficiencies of enzymes present only in liver and kidney, are not amenable to this approach. The same also pertains to enzyme deficiencies affecting other specific tissues. 

The second methodologic consideration relates to the type of cells which are used as controls for the biochemical determinations. While less a problem now, there was a tendency in some early investigations to use cultured skin fibroblasts or similar cells as controls for the cultured amniotic fluid cells. 

The measurement of potential Hg methylation and MeHg demethylation is significantly more complex than the measurement of HgT and MeHg concentrations in ambient samples. Methodological considerations include the maintenance of redox and temperature condition of samples during measurement, an understanding of the time course of both processes, and an understanding of the impact of spike level on the methylation and demethylation rate constants. Measurement of methylation and demethylation also requires the use of a tracer, and the abiUty to measure that trace analytically. 

Both the development and application of bioindicators present a number of methodological considerations. One key requirement is to relate dose/effects studies in the laboratory, and residne levels/efifects studies in the field. For many years, these stndies were condncted by different groups of scientists, and the cotmections were not made (Eisler 1987). Ideally, we should use bioindicators where there are clear links between exposnre levels, tissue levels, and effects (Burger and Gochfeld 2003). The most nseful bioindicators of those we suggest are those where the cotmections have been clearly made. 

T. van Vliet, F. van Schaik, W. H. Schreurs, and H. van den Berg, In vitro measurement of beta-carotene cleavage activity Methodological considerations and the effect of other carotenoids on beta-carotene cleavage, Int. J. Vitam. Nutr. Res. 66 (1996) 77-85. 

Stone, V., Johnston, H. and Schins, R.P.F. (2009) Development of in vitro systems for nanotoxicology methodological considerations. Critical Reviews in Toxicology, 39 (7), 613-626. 

Mullins, C.D., "Pharmacogenomics Methodological Considerations for Evaluating Outcomes and Cost-Effectiveness." Presented at the Ninth Annual Invitational Conference on Pharmacoeconomics. University of Arizona College of Pharmacy, Tucson, AZ, January 24, 2001. 

Organisation of Economic Cooperation and Development, Skin Sensitisation Testing Methodological Considerations, Tech. Rep. No. 78, Paris, 1999. 

Kuleff, I. and Pernicka, E. (1995). Instrumental neutron activation analysis of native copper - some methodological considerations. Journal of Radioanalytical and Nuclear... 

Rusted JM, Graupner L, Greenwood K. (1996). Methodological considerations in nicotine research the use of "denicotinised" cigarettes as the control condition in smoking studies. Psychopharmacology (Berlin). 125(2) 176-78. 

Frolich L, Dirr A, Gotz ME, GseU W, Reichmann H, et al. 1998. Acetylcholine in human CSF methodological considerations and levels in dementia of Alzheimer type. J Neural Transm 105 961... 

Wimo, A,. (2004) Cost effectiveness of chohnesterase inhibitors in the treatment of Alzheimer s disease a review with methodological considerations. Drug Aging, 21, 279-295. 

EPIDEMIOLOGICAL, RESEARCH, AND METHODOLOGICAL CONSIDERATION TABLE 53.1 Steps in Designing and Conducting a Clinical Trial (continued)... 

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