Analytical Differences Associated with Methodologies

Reagents for enzyme measurement are known not to be optimal for the different species (e.g., the substrate concentrations required for the measurement of plasma aspartate aminotransferase [AST/GOT] in rats, dogs, and monkeys differed from the concentrations used for these human plasma enzymes (Dooley 1979). However, there remains a lack of data on the optimal conditions—in terms of buffer, substrate concentration, reaction times, etc.— required for the different species. There are no nationally or internationally agreed-upon recommendations for laboratory animal samples, so most analysts use reagents formulated for human enzymes. Temperature 

Pyridoxal phosphate is a cofactor for both of the aspartate and alanine aminotransferases (AST ALT) and is often supplied as a separate component of reagent assay kits. The inclusion of pyridoxal phosphate can increase the measured activities of both aminotransferases activity by a small percentage (Stokol and Erb 1998), but this also can alter statistical differences observed between treatment groups in rat studies (Evans and Whitehorn 1995). 

Some other methodological issues relate to calibration and separation techniques. Very few specific proteins for the laboratory animals are available and of sufficient 

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A corollary of the last condition is that the theory should give results that are physically meaningful, such as non-negative spectra (DOSs), in both real and momentum space. It can be shown that negative spectra fail to satisfy causality and are sufficient to disqualify a certsdn formal construct as a viable theory of alloys. In addition, the methodology should yield results that are analytic in a mathematical sense and satisfy fundamental sum rules. For example, one set of such sum rules involves the integral over energy of the partial DOSs associated with different alloy species. 

An obvious factor for the inconsistent results of the effect of different intakes of dietary fiber on colorectal cancer is the variation in the analytical methodology used in different studies. There is also increasing evidence that total dietary complex carbohydrates may be as important as fiber. Analysis of stool weight from 20 populations in 12 countries showed that larger stools were correlated with a lower incidence of colon cancer. Intakes of starch and dietary fiber (rather than fiber alone) were the best dietary correlates with stool weight. A subsequent meta-analysis showed that greater consumption of starch (but not of NSPs) was associated with low risk of colorectal cancer in 12 populations. The examination also showed that fat and protein intakes correlated positively with risk. This meta-analysis is probably the first of its kind to... 

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