Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.5 (5'-nucleotidase)
 3,167 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We assessed, in 98 patients with cancer, the diagnostic value of measuring serum alkaline phosphatase, 5'-nucleotidase, gamma-glutamyltransferase, and glutamate dehydrogenase activities as an aid to detection of liver metastases. All four enzymes showed diagnostic value, but 5'-nucleotidase appeared to have the greatest. It showed the lowest false-positive results (7.4%) with the highest predictive value of a positive test (85.7%) and agreement (81.3%).. gamma-Glutamyltransferase showed the lowest proportion of false-negative results (2.8%), but was the least specific 35% false-positive results). Analysis of various test combinations showed that the best agreement (77.5%) was obtained when the patients were divided into those who had no or only one abnormal test result, and those who had two or more abnormal test results. However, this was not better than the agreement for 5' nucleotidase alone (81.3%). The agreement of 5'-nucleotidase and gamma-glutamyltransferase (i.e., both tests were positive or negative) was excellent (91.4%), but such agreement included only 67% of the patients with liver metastases.
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PMID:Value of alkaline phosphatase, 5'-nucleotidase, gamma-glutamyltransferase, and glutamate dehydrogenase activity measurements (single and combined) in serum in diagnosis of metastasis to the liver. 2 Oct 41

A study of the value of serum enzymes in 184 patients with colorectal cancer has been performed. The enzymes studied were gamma glutamyltransferase (gammaGT), alkaline phosphatase (AP), lactate dehydrogenase (LDH), 5'-nucleotidase (5'-NT), glutathione reductase (GR), alanine and aspartate transaminases. In patients without liver metastases, elevated enzyme levels were found in 11-55% preoperatively. 5'-NT showed the least number of elevated activities, while gammaGT activities were increased in 29% and LDH in 55%. The percentage of elevated enzyme levels rose significantly in the early postoperative period. Patients with liver metastases showed increased enzyme activities in 40-60% preoperatively: gammaGT was the most sensitive indicator. Increased enzyme activity was related to the degree of liver involvement with secondary tumor. With extensive liver metastases, gammaGT levels were increased in 82%. It is concluded that serum enzymes are of limited value in the preoperative detection of liver metastases, and particularly when tumor involvement of the liver is small.
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PMID:Serum enzymes in colorectal cancer. 3 19

The fluoropyrimidine deoxyribonucleotide 5-fluoro-2'-deoxyuridine 5'-monophosphate (FdUMP) was encapsulated in human erythrocytes by a procedure based on hypotonic hemolysis and isotonic resealing. Encapsulated FdUMP (up to 9 mumol/ml of packed erythrocytes) did not affect erythrocyte metabolism or morphology. Hemolysates were found to catalyze efficient dephosphorylation of FdUMP to yield nearly stoichiometric amounts of the corresponding deoxyribonucleoside 5-fluoro-2'-deoxyuridine (FdUrd), an antineoplastic drug showing selective cytotoxicity toward liver metastases from colorectal carcinomas. The dephosphorylation reaction had an apparent Km of 7.7 +/- 1.2 mM FdUMP at pH 7.4 and was remarkably slower at pH 8.2. ATP, GTP, and UTP inhibited both the disappearance of FdUMP and the formation of FdUrd in hemolysates. The enzyme responsible for the FdUMP-to-FdUrd conversion was identified with the deoxyribonucleotide-specific isozyme of erythrocyte pyrimidine 5'-nucleotidase (EC 3.1.3.5). Intracellular formation and subsequent release of FdUrd were observed in intact erythrocytes loaded with FdUMP. Inhibition of FdUrd release from these erythrocytes was obtained by raising the pH intracellularly and, alternatively, by coencapsulation of ATP. Autologous FdUMP-loaded erythrocytes might be used as endogenous bioreactors designed for time-programmed and liver-targeted delivery of FdUrd.
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PMID:Conversion of encapsulated 5-fluoro-2'-deoxyuridine 5'-monophosphate to the antineoplastic drug 5-fluoro-2'-deoxyuridine in human erythrocytes. 296 99

Liver metastases due to the more common neoplastic diseases such as colorectal, breast, or bronchogenic carcinoma are a frequent occurrence and are associated with an ominous prognosis. Earlier detection followed by appropriate therapeutic interventions might have a decided effect on the subsequent course of disease. Controversy exists over the selection of tests with the greatest sensitivity, specificity, and potential utility. Preliminary evidence suggest that gamma-glutamyl transpeptidase and 5'-nucleotidase may be of particular significance. Four enzymes--gamma-glutamyl transpeptidase, 5'-nucleotidase, leucine aminopeptidase, and alkaline phosphatase plus carcinoembryonic antigen--were compared in the same blood samples from selected patients with breast and small cell carcinoma of the lung. Gamma-Glutamyl transpeptidase was the most sensitive test with 28/29 (97%) patients with hepatic metastases having elevated enzymatic activity in their sera. For patients with small cell carcinoma of the lung followed serially, gamma-glutamyl transpeptidase activity was increased an average of 5 months before liver metastases were detected by clinical means. Two factors are important in the interpretation of the results of gamma-glutamyl transpeptidase analysis: (1) Hepatic dysfunction due to diseases other than metastatic tumor involvement can cause a rise in enzyme levels as can (2) medications or ethanol which activate the hepatic microsomal drug metabolizing system. Of particular importance, however, is the fact that antitumor chemotherapy, even intensive and multiple agent, did not appear to effect the enzyme activity in the sera of patients with breast or small cell carcinoma of the lung. Gamma-glutamyl transpeptidase in combination with carcinoembryonic antigen may be of particular value in detecting liver metastases and in assessing subsequent response to therapy.
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PMID:Biological markers as an aid in the clinical management of patients with liver metastases. 612 62