Urinary formiminoglutamic acid excretion in patients with neoplastic disease

Cobalamin-dependent metabolism in chronic myelogenous leukemia determined by deoxyuridine suppression test and the formiminoglutamic acid and methylmalonate excretion in urine

The cobalamin metabolism in chronic myelogenous leukemia (CML) was evaluated in 18 newly diagnosed and untreated patients by formiminoglutamic acid (FiGlu) and methyl malonic acid excretion (MMA) tests. A deoxyuridine (dU) suppression test of bone marrow cells was compared in patients with acute myelogenous leukemia (N = 5), myelodysplastic disease (N = 3), untreated pernicious anemia (N = 16), folate deficiency (N = 7), and a hospital reference group without signs of cobalamin or folate deficiency (N = 22). All had normal MMA excretion but 3 of 15 patients had increased FiGlu excretion. In vitro thymidine uptake in bone marrow cells of CML patients were lower (mean 40 fmol/106 cells) than pernicious anemia patients (115 fmol/106 cells). Methotrexate (MTX) increased the uptake in all cases. Addition of formyl-THF, methyltetrahydrofolate (methyl-THF), and pteroylglutamic acid (PGA) tended to normalize the effect of MTX. In pernicious anemia methyl-THF only decreased the uptake in combination with CN-Cbl. dU suppression values were significantly higher (6.3%) in CML than in the reference group (4.4%), but significantly lower than in pernicious anemia (41.6%) and folate deficiency (28.5%). The dU suppression values in bone marrow cells of CML patients correlated significantly with the transferrin saturation. In buffy coat cells dU suppression values were even higher (9.3%) than in bone marrow cells of the same CML patients. Addition of folate forms and CN-Cbl did not change the dU suppression values in CML, as it did in pernicious anemia. MTX increased dU suppression values significantly in all patients, but more in CML (64.5%) than in pernicious anemia (48.6%) and controls (49.8%). The MTX effect was to some extent neutralized by folate analogues with formyl-THF as the most effective followed by methyl-THF and lastly PGA. Methyl-THF also neutralized MTX in pernicious anemia, but its effect was certainly enhanced by addition of CN-Cbl. Thymidine uptake and dU suppression patterns were not significantly changed in CML after treatment with busulfan for 1 week or in accelerated phase. We concluded that signs of cobalamin or folate deficiency (apart from one patient) cannot be demonstrated in untreated CML. However, dU suppression was significantly increased and more so in circulating myeloid cells than in bone marrow. This indicates a deranged metabolism of deoxynucleotides which is independent of cobalamin and folates, and a difference between bone marrow cells and circulating cells. dU suppression is a valuable indicator of cobalamin deficiency.(ABSTRACT TRUNCATED AT 400 WORDS)

The role of folate deficiency in electrophysiological neuropathy of experimental hepatoma of the rats

Experimental hepatoma of the rats was induced by chronic administration of 3'-methyl-dimethylamino-azobenzene. The folate level of the hepatoma-bearing rats tended to be low as compared with that of normal controls, and the co-existence of folate deficiency and reduced motor nerve conduction velocity of the dorsal nerve trunks appeared not uncommon. The hepatoma-bearing rats revealed the disturbance of serine to glycine conversion in serum, and folate administration to them prevented electrophysiological neuropathy along with normalization of serine to glycine conversion. Therefore, the reduced motor nerve conduction velocity could be at least in part the result of a metabolic impairment due to folate deficiency.

Microangiopathic hemolytic anemia associated with radiation-induced hemangiosarcomas

A retrospective study of red blood cell parameters in 53 dogs with experimental radiation-induced hemangiosarcoma showed 24 had anemia. Morphologic alterations in red blood cells in peripheral blood films from anemic dogs included signs of regeneration (anisocytosis and polychromasia), hypochromasia, red cell fragmentation and acanthocytosis. The degree and type of red cell changes varied from dog to dog and generally correlated with the principal site of tumor involvement. Blood from dogs with tumors principally involving liver had red cell regeneration, fragmentation and acanthocytosis. Blood from dogs with tumors primarily involving the heart had only red cell fragmentation. Blood films from dogs with skeletal and pulmonary hemangiosarcomas were similar to blood films from dogs with hepatic hemangiosarcoma except that red cell alterations generally were less severe. Scanning and transmission electron micrographic evaluation of neoplastic tissue showed large amounts of fibrin within neoplastic vascular sinuses and disruption and distortion of red blood cells traversing these abnormal vascular beds. The red blood cell fragmentation syndrome associated with radiation-induced hemangiosarcomas therefore was considered to be a microangiopathic hemolytic anemia of localized origin.

Interrelationships between Vitamin B12 and folic acid in myelomatosis: cobalamin coenzyme and tetrahydrofolic acid function

Cobalamin and folate metabolism was investigated in 43 patients with myelomatosis, in 8 control subjects of similar age and 22 younger controls. Plasma total cobalamin was lower in myeloma patients than in either of the control groups and methylcobalamin (Me-Cbl) was disproportionately reduced. Erythrocyte levels of total cobalamin were very similar in patients and elderly controls but were half the levels in younger controls. Erythrocyte levels of Me-Cbl were slightly higher in patients than in the dlderly controls. FIGLU excretion after L-histidine was elevated in 53% of the patients but values did not correlate with serum or erythrocyte folate or with plasma total cobalamin. FIGLU excretion decreased after DL-methionine or Me-Cbl only in patients whose FIGLU excretion was initially high. The results are discussed in the light of the 'methylfolate trap hypothesis' and suggest that some patients with myelomatosis have insufficient activity of methionine synthetase to meet the additional metabolic demand for one carbon compounds.

Relative importance of formiminoglutamic and urocanic acid excretion after a histidine load

A thin-layer chromatographic method for the simultaneous assessment of formimino-glutamic (Figlu) and urocanic acid excretion after loading with 15 g. histidine has been applied to 15 control subjects and to 49 selected patients. Upper limits of normal excretion were determined for urocanic acid and Figlu alone (15 mg. and 30 mg/8 hr. respectively), and for the combined metabolites (40 mg./8 hr.). Of the 49 patients studied, 27 excreted total metabolites above 40 mg./8 hr.; of these 19 would have been revealed by their abnormal excretion of Figlu and 22 by their abnormal excretion of urocanic acid. Of 74 tests in the 64 subjects, urocanic acid was present in all but 27% of the tests, and in 29.8% of the tests urocanic acid was in excess of the amount of Figlu excreted. In six normal and six abnormal tests urocanic acid was the sole metabolite present. These results re-emphasize the value of estimating both histidine metabolites in tests for folate deficiency in man, and underline the greater relative importance of urocanic acid.

Folate Activity in Malignant Blood Diseases

Basal serum folate activity, serum folate clearance and folate output in the urine after folic acid loading, urocanic acid and formiminoglutamic acid output in the urine after histidine loading were determined on 27 patients with malignant blood diseases in therapeutic remission. The mean values for basal serum folate activity and for serum folate activity and urinary folate output after folic acid loading were significantly lower than normal, both in chronic myeloid leukemia and in Hodgkin's disease. On the contrary, in chronic lymphatic leukemia only after folic acid loading urinary folate output was significantly lower than normal. The median values for urinary excretion of histidine derivatives after histidine loading was higher than normal in Hodgkin's disease and in chronic lymphatic leukemia. Folate deficiency was observed in 16 out of the 27 patients under study. Comparative analysis of multiple test results showed different response patterns which can be attributed to different types of deficiency, namely tetrahydrofolate deficiency from primary folate deficiency and possibly tetrahydrofolate deficiency from folate metabolic abnormalities. Folate deficiency appeared to correlate with the activity of disease when expressed by such parameters as performance status and erythrocyte sedimentation rate. This applies to all patients as a group, and, as far as performance status is concerned, to the chronic lymphatic leukemia patients as a subgroup. Folate deficiency did not appear to correlate with other parameters of disease nor to induce, in the majority of patients, the typical hematologic features. Folate deficiency in malignant blood diseases is likely to be somehow related to the abnormal cell proliferation, through several possible mechanisms which are analysed and discussed.