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Congenital hemolytic anemia associated with pyrimidine 5'-nucleotidase deficiency is reported in two siblings. Both have had moderate chronic hemolytic anemia, splenomegaly, and jaundice since early infancy. The peripheral blood smear is characterized by striking red cell basophilic stippling. As this feature has been found in all previously reported cases, it should be the clue to the diagnosis.
The paper reports the results of danazol action in vivo and in vitro on 5'-nucleotidase activity of mouse peritoneal macrophages. The results showed, that danazol at a concentration of 10 M (the pharmacologic level in women taking 600 mg/day) significantly stimulated the enzyme activity.
It is shown that immunomodulator of bacterial origin salmozan causes alternations of sensitivity to mouse toxin in mice CBA. A correlation exists between the sensitivity to mouse toxin and the level of 5-nucleotidase of peritoneal exudate macrophages.
In studying the effect of X-irradiation of rats with a dose of 4 Gy at different dose rates (96 and 4.6 cGy/min) the authors have revealed an increase in 5'-nucleotidase activity at a high dose rate (the first 24 h following irradiation) and a decrease in protein-kinase activity at a low dose rate (on days 3 and 7). The preinjection of alpha-tocopherol prevents the changes observed.
In the present contribution a comparative study of histochemical mapping of the distribution of adenosine triphosphatase and 5-nucleotidase in the hind brain of mouse has been made. There are many similarities and dissimilarities between the distribution of these two enzymes in various nuclei, tracts and fiber bundles. The noteworthy differences are as follows:--1. The AP, NDNV, NI, NNH, NOAD, NOAM, NOI NPC, TS and SG are very intensely positive for ATPase whereas, in 5-NUC study none of these nuclei demonstrates intensity of such degree. 2. Nucleus ambiguus is intensely positive for ATPase and is completely negative for 5-NUC. 3. The nucleus n. facialis is intensely positive for ATPase and is moderately positive for 5-NUC. 4. NC, GN, PN, PCI and TC are completely negative for 5-NUC. In ATPase preparations only GN is negative and the rest of the areas demonstrate intensity of various degrees. Along with these differences, similarities in the intensity of both enzymes in various nuclei, tracts and fibrous bundles also exist. An attempt has been made to correlate all the aforesaid differences and similarities in the distribution of these two enzymes with the functional nature of the various areas of hind brain of mouse.
We analyzed cytosolic 5'-(3')-nucleotidase (dNT-1) mRNA expression by quantitative polymerase chain reaction at diagnosis in leukemic blasts from 114 patients with acute myeloid leukemia (AML) treated with ara-C. Our results show that low dNT-1 mRNA expression in leukemic blasts at diagnosis is correlated with a worse clinical outcome and suggest that this enzyme may have a role in sensitivity to ara-C in AML patients.
Ecto-5'-nucleotidase (ecto-5'-NUC, EC 3.1.3.5., CD73) is a plasma membrane enzyme, which catalyzes the hydrolytic dephosphorylation of purine nucleotides to the corresponding nucleosides so that they can pass through the plasma membrane. The distribution of ecto-5'-NUC is heterogeneous, but all blood mononuclear cell (BMC) subpopulations investigated until now have had ecto-5'-NUC activity. Purified natural killer (NK) cells were prepared by fluorescence-activated cell sorting of CD16-positive cells (purity 94%). In purified NK cells the ecto-5'-NUC activity was less than 1 U/10(6) as estimated by a radioisotope method. Using a cytochemical assay, the proportion of cells with activity was less than 1%. The most likely explanation is that NK cells have no ecto-5'-NUC activity and that the very small ecto-5'-NUC activity observed in this study was caused by contaminating non-NK cells. NK cells thus constitute the only BMC subset known without ecto-5'-NUC activity.
OBJECTIVE: To determine the relationship between double-contrast manifestation and 5'-nucleotidase (5'-NT) of gastric carcinoma. METHODS: Serum specimens were taken from 41 cases with gastric carcinoma documented by double-contrast visualization and pathology. 5'-NT activity was determined by spectrophotometry. 40 healthy subjects were recruited and studied as normal controls. RESULTS: The serum level of 5'-NT(1.14 u/ml) in gastric carcinoma group was lower than that of control group (2.60 u/ml) (P < 0.05). Anatomically, it was found that the 5'-NT level of gastric carcinoma gradually increased as the sites of the tumor lined up from the orifice (0.98 u/ml) to the antrum (1.28 u/ml) via the body (1.20 u/ml). 5'-NT of the ulcerative type (0.96 u/ml) was lower than that of the fungating type (1.12 u/ml) or the infiltrating type (1.40 u/ml). 5'-NT(1.53 u/ml) of stage IV gastric carcinoma was higher than that of stage 1 (0.83 u/ml), stage I (0.98 u/ml) and stage III (1.03 u/ml) (P < 0.05). CONCLUSION: The change of 5'-NT from gastric carcinoma was correlated with the site, type or stage shown on the double-contrast images of the tumor.
Serial measurements of alkaline phosphatase and 5'-nucleotidase multiple forms in two patients undergoing surgical procedures to release biliary obstruction suggested an inverse relationship between high-M(r) isoforms and serum bile acids concentrations. Furthermore, the study of several groups of patients with cholestatic disorders confirmed this inverse correlation. Mechanisms responsible for these observations are discussed.
Four different gene mutations were identified in five unrelated Portuguese patients with pyrimidine 5'-nucleotidase type I (P5'N-I) deficient chronic hemolytic anemia. Mutations 502G-->C (168Gly-->Arg), 773T-->C (258Ile-->Thr) and the insertion of an Alu element in exon 9, leading to skipping of this exon in the mRNA transcript, are newly described mutations whereas mutation 425T-->C (142Leu-->Pro) has been previously reported.
The cerium-based method was used to demonstrate cytochemically the ultrastructural localization of alkaline phosphatase (ALPase), 5'-nucleotidase (5'-Nase) and magnesium-dependent adenosine triphosphatase (Mg-ATPase) on the transitional epithelium of the rat urinary bladder. The reaction product for ALPase was found on the plasma membrane of all epithelial cells, except the luminal surface of superficial cells. The activity of 5'-Nase appeared on the plasma membrane of all bladder transitional epithelial cells, including the free surface of superficial cells. The Mg-ATPase reaction product was seen on the plasma membrane of superficial, intermediate and basal cells, but never on the luminal surface of superficial cells and it was only occasionally seen on the basal surface. The possible functions of these phosphatases have been discussed, and it was emphasized that the 5'-Nase activity present on the luminal surface of superficial cells may play a special role in the membrane movement of these cells in the transitional epithelium.
Following peripheral nerve injury the proliferation of 5'-nucleotidase positive microglial cells has been noticed around projective motoneurons and autonomic preganglionic neurons of the central nervous system. Similar events were observed in the central arborization fields of the primary sensory fibers. Our results may suggest an important role of glial cells in the neuronal plasticity.
1. Activity of a 5'-nucleotidase which preferentially hydrolyses IMP and GMP was determined by immunotitration in various mammalian tissues. 2. Activity per g of rat tissue was high in testis and spleen and low in skeletal muscle. 3. In human cells, the activity was high in fibroblasts and low in erythrocytes.
Thirteen immunoglobulin-secreting mycoplasma-free human cell lines were treated with increasing concentrations of lymphoblastoid interferon-alpha (IFN-alpha) in order to study the activity of their CD73 ecto-5'-nucleotidase (5'N), their rate of growth and their immunoglobulin (Ig) production. Although IFN-alpha did not immediately affect the activity of the 5'N on the cell plasma membranes, the class of Ig secreted by the cell lines determined whether culturing the cells in the presence of IFN-alpha gave a small increase in the 5'N enzyme activity (IgM), or had no effect (IgE), or showed a marked decrease in activity (IgG). The 5'N activity of two IgG4-secreting clones was more suppressed by IFN-alpha than that of the four IgG1-secreting clones. The clone with the highest 5'N was killed by IFN-alpha. A high 5'N activity inhibited the growth rate of the cells, since the rate of growth of the three IgG-producing lines with high 5'N was increased when their 5'N was inhibited by increasing concentrations of IFN-alpha. The growth rate of three other Ig-producing lines was uninhibited by up to 10(5) U/ml IFN-alpha, whereas the rest were partially or strongly inhibited. Excluding the clone which died, 10/11 lines or cultures increased their Ig/cell by a mean of 25% at 100 U/ml IFN-alpha; their total Ig production also increased despite any growth inhibition. One IgG-secreting clone decreased its Ig production at 100 U/ml IFN-alpha by 11%. The Ig/cell of 4/5 of the cell lines increased with IFN-alpha concentrations up to at least 10(4) U/ml. The increase in Ig/cell was not related to the class of Ig, the growth rate of the cells or the amount of 5'N.
Ecto 5' nucleotidase (5'NT) is an integral plasma membrane enzyme located on most mammalian cells, and it is zinc dependent. We assayed 5'NT activity in the lymphocytes of two groups of subjects. The first group of six subjects had a mild state of zinc deficiency, as measured on the basis of zinc levels in lymphocytes, granulocytes, and platelets, but were otherwise healthy. They received 50 mg zinc as acetate orally for 12 weeks. The second six subjects were normal human volunteers in whom a mild state of zinc deficiency was induced experimentally by dietary techniques (4.2 to 5.6 mg daily zinc intake). For the assay of 5'NT, intact lymphocytes were incubated with 8-14C-labeled inosine monophosphate as substrate. Product and substrate were separated by thin-layer chromatography. Zinc level in cells was measured by flameless atomic absorption technique. In the first group of subjects with zinc deficiency, the decreased activity of 5'NT was corrected and the cellular zinc levels were normalized by oral zinc supplementation (p less than 0.01). In the second group of subjects, the baseline data were compared with those in early zinc depletion (4 to 8 weeks) and late depletion periods (greater than 20 weeks). A decrease in the activity of 5'NT was observed during the early zinc depletion phase. Zinc levels in lymphocytes, granulocytes, and platelets decreased significantly only during the late zinc depletion phase (p less than 0.01). Plasma zinc level did not change even during the late zinc depletion phase. Our studies show that 5'NT activity may be a sensitive and useful indicator of mild deficiency of zinc in human subjects.(ABSTRACT TRUNCATED AT 250 WORDS)
Interaction of the glycosyl phosphatidylinositol-linked differentiation Ag CD73 (ecto-5'-nucleotidase) with the CD73-specific mAb 1E9 generates agonistic signals that strongly synergize with T cell activation induced by CD3 and CD2 mAb. This synergy is observed only when 1E9 is immobilized on plastic and occurs in the absence of accessory cells or exogenous lymphokines. 1E9 induces a rapid (though transient) increase in [Ca2+]i in a minor proportion (20 to 30%) of unfractionated T lymphocytes (presumably CD73+ cells). However, this [Ca2+]i mobilization is not sufficient to fully activate CD73+ T cells, as shown by the requirement of additional signals such as CD3 or CD2 stimulation to initiate T cell proliferation. These signals cannot be substituted by the exogenous lymphokines, rIL-1, rIL-2, or rIL-4, or PMA (when T cells are rigorously depleted of monocytes). These data indicate that CD73 may behave as an accessory molecule regulating interactions between T cells and antigens or APC. A comparison was carried out with mAb 9.3 to the differentiation Ag CD28, another agonistic molecule with activating properties similar to CD73. Despite their lower percentage, the ability of CD73+ T cells to amplify the proliferation induced by CD3 or CD2 mAb was equivalent or even greater than that of CD28+ T cells. Once activated, CD73+ cells may recruit the remaining (CD73-) cells primed by CD3 or CD2 stimulation. Based on these data, we suggest that CD73+ T lymphocytes may be a specialized subset to amplify immune responses originated by the CD3 and CD2 activation pathways. Finally, the functional association between CD73 and integral membrane molecules like CD3 and CD2 suggests that GPI-anchored molecules may play a role in transmembrane signaling mediated by conventional second messenger systems.
One of the earlier effects of poliovirus was the maintaining of a high level of Hela cells 5'-nucleotidase activity (maximal efficiency for a virus/cell ratio = 500 ID 50/cell) (ID50:50% Infections Dose). The activity decreased when cells were suspended in the presence of EDTA(EDTA:Ethylene Diamine Tetracetic Acid) and was partially restored by adding 10 mM Mg++ interactions are discussed.
Ecto-5'nucleotidase (5'NT; CD73) expression was studied with a monoclonal antibody (7G2) and a radiochemical assay and compared with the expression of other antigens in B-cell-lineage leukemias on cells from 100 leukemic patients and two cell lines. A B-cell origin was confirmed by the expression of CD19 and HLA-DR. Four stages of B-cell leukemias were defined: stage I (pro-B) as CD10-, cytoplasmic mu- (c mu-), surface Ig- (sIg-); stage II (cALL) as CD10+/c mu-/sIg-; stage III (pre-B) as CD10+ or -/c mu+/sIg-; and stage IV (B) as CD10-/c mu-/sIg+. A linear correlation was found between immunohistochemical and radiochemical determination of 5'NT (r = .86). 5'NT expression was low in T-cell leukemias and stage I, high in stages II and III, and low again in stage IV of B-cell leukemias. 5'NT expression was not related to c mu, CD20, CD21, CD22, CD34, and terminal deoxynucleotidyl transferase (TdT) expression, but was significantly related to CD10 and inversely related to kappa/lambda expression. However, the 5'NT activity in CD10+ leukemias (stages II and III) shows a very wide range. Within the group of CD10+ leukemias no differences were detected between 5'NT+ and 5'NT- cells in their expression of other B-cell antigens. We conclude that the place of 5'NT in leukemias corresponding to early stages of B-cell development has been characterized. 5'NT is expressed in CD10+ stages and decreases before the expression of sIgs. Future studies should make clear whether a high expression of this enzyme in CD10+ stages is a normal maturation phenomenon or a malignant phenomenon.