Discrimination Diseases

Fig. 8. Plot of data from patients having Hver diseases A or B or unknown X (a) on two blood enzymes (b) scores of points on the first two eigenvectors obtained from an eight-dimensional enzyme space and (c) eigenvector plot of the variance weighted data. Variance weights ranged from 3.5 to 1.2 for the eight blood enzymes measured. A weight of 1.0 indicates no discrimination information (22).

Solberg and co-workers have applied discriminate analysis of clinical laboratory tests combined with careful clinical and anatomic diagnoses of liver disease in order to determine which combinations of the many dozen liver diagnostic tests available are the bes t ( ). These authors found that the measurement of GPT, GMT, GOT, ALP and ceruloplasmin were the most useful enzymatic tests, when combined with other non-enzymatic tests such as the measurement of bilirubin, cholesterol, hepatitis-B associated Australian antigen, etc. Another group of highly useful enzymes, not discussed in this review, are those clotting factors and the enzyme cholinesterase which are synthesized by the liver cells. 

Diagnosis of liver diseases by laboratory results and discriminant analysis. Identification of best combinations of laboratory tests. Scand. J. Clin. Lab. Invest. 

D. Coomans, M. Jonckheer, D.L. Massait, I. Broeckaert and P. Blockx, The application of linear discriminant analysis in the diagnosis of thyroid diseases. Anal. Chim. Acta, 103 (1978) 409-415. 

Lione LA, Carter RJ, Hunt MJ, Bates GP, Morton AJ, Dunnett SB. Selective discrimination learning impairments in mice expressing the human Huntington s disease mutation. J Neurosci 1999 19 10428— 10437. 

Sawle, G. V., Playford, E. D., Burn, D. J. et al. Separating Parkinson s disease from normality. Discriminant function analysis of fluorodopa F-18 positron emission tomography data. Arch. Neurol. 51 237-243,1994. 

In a nationwide interview survey conducted in the fall of 2001 by Peter D. Hart Research Associates, Inc., respondents were asked whether genetic research will result in medical treatments and cures for diseases. Forty percent said that it will almost certainly happen, and 53% said that it will probably happen (Peter D. Hart, 2001). When asked whether many serious diseases will be eradicated as a result of genetic research, 20% said that it will almost certainly happen and 54% said that it will probably happen. The responses on genetic discrimination are particularly interesting. When asked whether health insurance companies will use genetic information to deny people coverage if they are predisposed to diseases, 32% said that it will... 

An interesting example of the above difference is l-DOPA 4, which is used in the treatment of Parkinson s disease. The active drug is the achiral compound dopamine formed from 4 via in vivo decarboxylation. As dopamine cannot cross the blood-brain barrier to reach the required site of action, the prodrug 4 is administered. Enzyme-catalyzed in vivo decarboxylation releases the drug in its active form (dopamine). The enzyme l-DOPA decarboxylase, however, discriminates the stereoisomers of DOPA specifically and only decarboxylates the L-enantiomer of 4. It is therefore essential to administer DOPA in its pure L-form. Otherwise, the accumulation of d-DOPA, which cannot be metabolized by enzymes in the human body, may be dangerous. Currently l-DOPA is prepared on an industrial scale via asymmetric catalytic hydrogenation. 

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