Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An immunoenzyme assay for detection of platelet antibodies and suitable for routine use is described. Purified rabbit IgG anti-human IgG antibodies are conjugated to beta-galactosidase with meta-maleimidobenzoyl-hydroxysuccinimide ester as a bifunctional reagent and o-nitrophenyl-beta-galactopyranoside as a substrate to evaluate the enzymatic activity of the labeled antiglobulin. The sera of 26 patients suffering from various diseases (acute leukemia, aplastic anemia and systemic lupus erythematosus) and 40 control subjects were assayed with the enzyme-labeled reagent and, for comparison, with an indirect immunofluorescence technique. Half of these patients had never been transfused. Platelet antibodies were detected by both assays in all the transfused patients except one, and in 3 out of 13 non-transfused patients. The sera of all the control subjects were negative. Quantitation of platelet antibodies was obtained by a sensitive antiglobulin absorption technique. A method for standardization of the reagents allowing comparison of results obtained in the same patient at different times and suitable for long-term follow-up studies is also described.
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PMID:An immunoenzymatic assay for the detection and quantitation of platelet antibodies: the platelet beta-galactosidase test (PGT). 679 85

Neutral glycosphingolipids were isolated from the malignant cells of several patients with different types of acute leukemia. Analyses were performed by high performance liquid chromatography combined with enzymatic hydrolysis of glycosphingolipids using glycosidases (Escherichia freundii endo-beta-galactosidase, jack bean beta-galactosidase, and beef kidney beta-hexosaminidase). We found that acute leukemia cells contain very little or none of the more complex neutral glycosphingolipids that are found in normal leukocytes or chronic leukemia cells. Lymphoblasts, in particular, are rich in neutral glycosphingolipids with only 1 or 2 carbohydrate units. The most significant finding of our study was that, in contrast to normal leukocytes and chronic leukemia cells which have a single predominant tetraosylceramide species, acute leukemia cells (9 out of 10 patients analyzed) were found to have significant amounts of both globo (GalNAc beta 1 leads to 3Gal alpha 1 leads to 4Gal beta 1 leads to 4Glc beta 1 leads to 1ceramide) and neolactotetraosylceramide (Gal beta 1 leads to 4GlcNAc beta 1 leads to 3Gal beta 1 leads to 4Glc beta 1 leads to 1ceramide). These results indicate that the composition of neutral glycosphingolipids in acute leukemia cells differs significantly from that found in normal or chronic leukemia cells.
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PMID:Neutral glycosphingolipids of human acute leukemias. 695 4

The majority of immunotherapy-based gene therapy protocols consist of ex vivo gene transfer in tumor cells. To prevent further in vivo growth, modified cells must be irradiated before reinjection into patients. The present study examines the effects of gamma-irradiation on transgene expression in transduced leukemic cells. Human and murine leukemic cells were transfected with retroviral vectors or plasmids carrying beta-galactosidase, GM-CSF or CD80 genes. Fresh leukemic cells from patients with acute myeloid leukemia (AML) were transfected with AdZ.F(pK7) adenoviral vector. gamma-irradiation at various lethal doses enhanced transgene expression in leukemic cell lines and fresh AML cells when the gene of interest was under CMV promoter but not when SV40 promoter was used. Oxidative stress also enhanced transgene expression and both irradiation and oxidative stress effects were inhibited by addition of N-acetyl-L-cysteine, a thiol anti-oxidant, indicating the involvement of reactive oxygen species. Transgene expression was also enhanced in vivo 48 and 120 h after subcutaneous injection of irradiated leukemic cells in syngeneic mice. These results show that a cell vaccine protocol using ex vivo gene transfer of transduced cells might be feasible in acute leukemia even if leukemic cells must be irradiated at lethal doses prior to reinjection to patients.
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PMID:Gamma-irradiation enhances transgene expression in leukemic cells. 1257 30