Deoxycytidylate deaminase in the diagnosis of acute myocardial infarction.

The diagnostic value of deoxycytidylate deaminase (dCMP) in the diagnosis of acute myocardial infarction (AMI) was examined in 31 healthy controls and 32 patients with proven AMI. Its specificity in normal controls was 93.5%. Its highest levels were measured on the 3rd to 5th post-infarct day, when its sensitivity reached 97.5%. Its diagnostic performance was similar to that of SGOT, total LDH1/LDH2 ratio greater than 1, total CPK and CPK-MB. Its peak levels showed a highly significant correlation (p less than 0.001) with those of the above enzymes. The measurement of dCMP may be a valuable complement in the diagnosis of AMI since this enzyme is not affected by lung infarction or hemolysis. Moreover, since it expresses tissue regeneration rather than destruction it may aid in the assessment of various interventions designed for the promotion of myocardial healing process.

Serum deoxycytidylate deaminase as an index of high-risk pregnancy.

Serum deoxycytidylate deaminase (EC 3.5.4.12, dCMP deaminase) activity was routinely estimated over 7 years in 2460 pregnancies. The results confirm that elevated dCMP deaminase activity (greater than 4.8 units) is associated with the development of pre-eclampsia but not with essential hypertension in pregnancy; a high rising level can precede eclampsia. Elevated enzyme activity was also found in women who developed jaundice in pregnancy and in some with apparently normal pregnancies. An unexpected finding was that these so called 'false positive' high levels were associated with all the unexplained intrauterine fetal deaths that occurred later in pregnancy. Although elevated dCMP deaminase levels may be associated with a normal outcome, persisting high levels indicate the need for careful monitoring of fetal well being and, in the presence of any other sign of placental insufficiency, delivery should be expedited.

Activity of serum cytidine deaminase during pregnancy.

A simple and reliable method for the estimation of cytidine deaminase (cytidine aminohydrolase; EC 3.5.4.5) activity in pregnancy serum is described. This enzyme does not require magnesium for activation and is also more stable than deoxycytidylate deaminase (dCMP deaminase, dCMP aminohydrolase; EC 3.5.4.12). There was excellent correlation between the two enzymes (r = 0.92). Both enzymes showed increased activity in abnormal pregnancy. Both enzymes activities were found to be similar in 1305 maternal serum samples and therefore due to the simplicity of cytidine deaminase estimation it is recommended for the screening of large numbers of antenatal sera for abnormal pregnancies.

Serum deoxycytidylate deaminase activity after myocardial infarction.

The activity of serum deoxycytidylate deaminase, not hitherto reported to increase after myocardial infarction, has been investigated and the results have been related to other cardiac enzymes, including the MB fraction of creatine phosphokinase. Deoxycytidylate deaminase was found to increase to maximum activity on the third day after infarction. It may therefore be added to the list of 'cardiac enzymes.

Plasma urate and serum deoxycytidylate deaminase measurements for the early diagnosis of pre-eclampsia.

The value of measuring plasma urate and serum deoxycytidylate deaminase (dCMP deaminase) for the early diagnosis of pre-eclampsia has been investigated in 45 patients. A combination of increased blood pressure and increased plasma urate identified 19 patients with a high incidence of fetal and maternal morbidity ascribable to pre-eclampsia. Seventeen of the 19 patients also had an increased serum dCMP deaminase. Serial antenatal observations for a mean period of 104 days (36-179 days) on 33 of the patients demonstrated that plasma urate and serum dCMP deaminase increased together as early changes in the development of pre-eclampsia. In six patients, blood pressure, plasma urate and serum dCMP deaminase all increased but in only one was the rise in blood pressure the first change. Elevations of plasma urate and serum dCMP deaminase are therefore both early features of pre-eclampsia. Serial measurements can give warning of the disorder before the appearance of other clinical features. The change in dCMP deaminase is probably another reflection of early renal involvement in the pre-eclamptic process.

A rapid method for the determination of deoxycytidylate deaminase activity in pregnancy serum.

A method is described for determining the activity of deoxycytidylate deaminase in serum. The ammonia liberated from deoxycytidine monophosphate has been specifically determined by enzymatic amination of alpha-ketoglutarate using glutamate dehydrogenase. The concurrent oxidation of NADH2 at 340 nm was proportional to the ammonia liberated from deoxycytidine monophosphate. Using the technique described, a result would be available to the clinician in under 4.5 h. The "normal activity" for deoxycytidine deaminase in normal male, female and pregnancy sera has been determined.