Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.3.1 (alkaline phosphatase)
 47,916 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A putative reservoir of functional plasma membrane proteins, the secretory vesicle identified by latent alkaline phosphatase and tetranectin, has previously been demonstrated based on indirect evidence (Borregaard, N., Miller, L. J., and Springer, T. A. (1987) Science 237, 1204-1206; Borregaard, N., Christensen, L., Bjerrum, O. W., Birgens, H. S., and Clemmesen, I. (1990) J. Clin. Invest. 85, 408-416). Difficulties in separating plasma membranes from this entity by density gradient centrifugation has prohibited discriminative dynamic and quantitative studies of secretory vesicles and plasma membranes. By combining density centrifugation with free flow electrophoresis we overcame this obstacle. Freshly prepared unperturbed human neutrophils were subjected to nitrogen cavitation followed by density centrifugation on Percoll gradients. Light membrane fractions containing plasma membranes and secretory vesicles were applied to high voltage free flow electrophoresis on an Elphor VaP 22. Plasma membrane vesicles, identified by HLA class I antigen mixed enzyme-linked immunosorbent assay (Bjerrum, O. W., and Borregaard, N. (1990) Scand. J. Immunol. 31, 305-313) and 125I applied to cells before cavitation, were clearly separated from secretory vesicles. Electron microscopy revealed a morphology typical of plasma membranes in the former fraction and a population of vesicles with markedly different appearance in the latter. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles demonstrated distinct differences in protein patterns between the two fractions. Superoxide generating capacity induced by sodium dodecyl sulfate and cytosol, an entity traditionally ascribed to the plasma membrane, was largely confined to fractions containing secretory vesicles. Thus, the majority of membrane-bound NADPH oxidase components of light membranes of human neutrophils colocalize with secretory vesicles.
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PMID:Separation of human neutrophil plasma membrane from intracellular vesicles containing alkaline phosphatase and NADPH oxidase activity by free flow electrophoresis. 163 31

This study introduces a simple, reproducible assay for HLA class I antigen using antibodies against beta 2-microglobulin and the heavy chain on HLA. The sandwich technique was named mixed enzyme-linked immunosorbent assay (MELISA), and was designed for identification of plasma membranes in neutrophil subcellular fractions. The subcellular localization of HLA was identical to that of other plasma membrane markers, [3H]concanavalin A and detergent-independent alkaline phosphatase, and was unchanged by stimulation of cells by weak and strong secretagogues. In addition to the presence as part of the HLA complex in the plasma membrane uncomplexed beta 2-microglobulin is present in the specific granules of neutrophils. However, the release of beta 2-microglobulin from intact neutrophils stimulated with formyl-methionylleucylphenylalanine was much higher than could be explained by exocytosis of specific granules. Subcellular fractionation studies demonstrated that beta 2-microglobulin is localized in fractions characterized by latent alkaline phosphatase and released from this novel secretory compartment in response to stimulation with formyl-methionylleucylphenylalanine.
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PMID:Mixed enzyme-linked immunosorbent assay (MELISA) for HLA class I antigen: a plasma membrane marker. 218 25

The aim of this study was to analyse the change in tissue distribution of HLA class I and class II molecules in patients during the course of liver transplantation. Sixty-one liver biopsies were analysed in 24 patients with or without rejection (acute or chronic) episode. In 93% of cases with chronic rejection and in 48% of cases with acute rejection episodes, HLA class I antigens are expressed in the membrane and/or the cytoplasm of hepatocytes. The expression of these molecules was significantly correlated with the ASP (aspartate amino transferase), AP (alkaline phosphatase), the bile duct damage and the centrolobular lesions. In contrast, the expression of HLA class II molecules is not correlated with either the type of rejection, the biological or histological findings. A strong expression of HLA class I antigen on hepatocytes after day 60 may be one of the best signs of chronic rejection.
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PMID:Distribution of the MHC antigens after liver transplantation: relationship with biochemical and histological parameters. 237 88

HLA class I and II antigen expression was studied in normal mucosa, adenoma and colon carcinoma. Alkaline phosphatase anti-alkaline phosphatase (APAAP) staining techniques were used in cryostatic sections with anti-HLA-ABC and DR,DP,DQ monoclonal antibodies. All normal mucosa were intensely positive for HLA class I antigen expression, while failing to express class II molecules, except in mucosa adjacent to tumors (15/19 cases). All adenomatous polyps expressed HLA class I antigen, while the intensity of class II expression (DR greater than DQ greater than DP) was paralleled by the degree of dysplasia. In colon carcinoma, the loss of class I expression was seen in 4 out of 32 cases, and class II expression was found to be heterogeneous in 16 of these 32 cases (DR greater than DP greater than DQ). No relationship was noted between class II expression and degree of differentiation. However a correlation was seen between HLA-DR antigen expression and degree of invasiveness, mononuclear infiltrate and prognosis, according to Jass's criteria.
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PMID:Class I and II HLA antigen distribution in normal mucosa, adenoma and colon carcinoma: relation with malignancy and invasiveness. 285 3

Neutrophil granulocytes are the most important white blood cells in the combat of non-viral infections. Circumstantial evidence indicates that neutrophils in addition modulate the inflammatory process. Production of neutrophils takes place in the bone marrow, and mature cells egress to the circulation. Neutrophils emigrate following activation from the vessels into the tissues (chemotaxis). During this process neutrophils generate reactive oxygen species (respiratory burst) and mobilize intracellular compartments (degranulation). By degranulation, neutrophils exercise influence on nearby cells or bacteria by extracellular release of intragranular proteins (exocytosis), and intensify plasma membrane-related processes, such as chemotaxis and respiratory burst, by translocation of membrane-bound proteins to the surface (upregulation). Ultimately, microorganisms may be killed intracellularly following engulfment (phagocytosis). The thesis presents results of protein-chemical analysis of human neutrophils, based on studies of intact cells and subcellular structures (subcellular fractionation). By fractionation, azurophil granules and specific granules can be disunited from each other and from plasma membrane and secretory vesicles. Only partial separation of plasma membrane and secretory vesicles can be obtained. Subcellular structures are identified by markers, e.g. vitamin B12 binding protein for specific granules, and latent alkaline phosphatase for secretory vesicles. The studies demonstrated tetranectin in neutrophils, localized exclusively in the secretory vesicles. Tetranectin was released by incubation of neutrophils in the presence of weak, inflammatory stimuli and paralleled the upregulation of alkaline phosphatase, but preceded degranulation of specific granules. Alkaline phosphatase has previously been employed as a plasma membrane marker. A novel ELISA for HLA class I antigen was introduced as a new plasma membrane marker. Results obtained by this assay showed upregulation of alkaline phosphatase occurring without a concurrent redistribution of HLA antigen. This indicates that the two proteins are localized in separate compartments. Upregulation of alkaline phosphatase induced by weak stimuli, however, paralleled the translocation of cytochrome b559, anticipated to be the terminal component in the respiratory burst, and known to be localized primarily in the specific granules. The present studies indicate that 15% of cytochrome b is localized in the secretory vesicles. An ELISA was established for quantitation of beta 2-microglobulin, the light chain of HLA class I antigens. The concentration of beta 2-microglobulin in plasma from patients with chronic myeloid leukaemia was found to correlate with the concentration of vitamin B12 binding protein.4+ Measurements in neutrophils demonstrated 65% of the total content of beta 2-microglobulin to be localized in the specific granules, and 20% to be present in secretory vesicles.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Human neutrophil structure and function with special reference to cytochrome b559 and beta 2-microglobulin. 849 95

In search of factors governing the accumulation of tumor infiltrating lymphocytes (TIL), frozen sections from fresh surgical specimens of laryngeal carcinoma (n = 36) were tested by alkaline phosphatase-anti-alkaline phosphatase (APAAP) immunohistochemistry for monomorphic determinants of HLA class I and class II expression on tumor cells and for the distribution of lymphoid cells bearing CD differentiation antigens. Cell subsets were quantitated in two tumor compartments, tumor mass and tumor stroma, by computer-assisted image analysis. In a portion of examined samples lymphoid cell suspension was isolated from cancerous tissues and assessed by flow cytometry. It has been found that T cells, localized mostly in tumor stroma, were predominant cell population in the tumor microenvironment. Their ability to penetrate tumor mass but not tumor stroma, by CD8+ T cells in particular, but also by natural killer (NK) cells, was associated with HLA class I antigen expression on tumor cells. In flow cytometric analysis activated T lymphocytes (CD3+DR+) were abundant in HLA+ tumors as compared to HLA- ones. In 4 year follow up of 20 patients the mortality was higher in HLA- group but the data were not statistically significant. These results show that HLA class I expression on tumor cells favor penetration of cytotoxic lymphoid cells into tumor mass, at least in the laryngeal cancer.
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PMID:Tumor infiltrating lymphocytes in HLA+ and HLA- laryngeal cancer--quantitative approach. 1047 Apr 43