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

The identification of atypical testicular germ cells is often difficult by by routine histologic examination. By immunohistochemical detection of placental alkaline phosphatase (PLAP) and by periodic acid Schiff staining of glycogen, atypical germ cells were easily identified in testicular samples. Forty-one fetal and adult testes were used for a preliminary study, and 121 testes from infants and adults with either cryptorchidism or germ cell tumors were studied for the presence of atypical germ cells. Two types of clear germ cells were differentiated histochemically, and one with PLAP-positive cell surfaces and glycogen-rich cytoplasm was considered to be atypical. The alkaline phosphatase of atypical germ cells appeared to be similar to that found in a few germ cells of early fetal testes. The atypical germ cells seemed to be multi-potential malignant cells capable of developing not only into seminoma but also into other germ cell tumors. Only in yolk sac tumor of infants were the atypical germ cells absent from tumor-adjacent seminiferous tubules.
 ...
PMID:Identification of testicular atypical germ cells by an immunohistochemical technique for placental alkaline phosphatase. 362 Nov 15

Specific assays for human intestinal and liver alkaline phosphatases were developed by use of isozyme specific monoclonal antibodies bound to paper discs. The assays are fast, specific and convenient to use as demonstrated by determinations of alkaline phosphatase isozymes in sera and tissues. In sera from forty healthy individuals the activity of the tissue unspecific alkaline phosphatase was determined to 32 +/- 12 IU/l (mean +/- SD). The activity of the intestinal alkaline phosphatase was found to be ten-fold lower, 3.5 +/- 6.3 IU/l (mean +/- SD), and of the placental alkaline phosphatase another ten-fold lower, 0.3 +/- 0.2 IU/l (mean +/- SD), than that of the tissue unspecific alkaline phosphatase. Several normal tissues contained all three isozymes, the intestinal mucosa, for example, which besides intestinal alkaline phosphatase also expresses trace amounts of placental and liver-bone-kidney alkaline phosphatase. Seminomas, known to express eutopically placental-like alkaline phosphatase were demonstrated to contain increased levels of both intestinal and liver-bone-kidney alkaline phosphatases as compared to the normal testis.
 ...
PMID:Specific assays for human alkaline phosphatase isozymes. 362 3

The three human isozymes of alkaline phosphatases were quantitatively determined in normal testis and seminoma tissues. The highly selective assays were based on isozyme specific monoclonal antibodies. In the normal testis approximately 90% of the catalytic activity originates from the tissue unspecific alkaline phosphatase, and the remaining activity was due to trace expression of both intestinal (approximately 5%) and placental alkaline phosphatase (PLAP) or PLAP-like isozyme (approximately 5%). In homogenates of seminoma tissues, highly increased levels of all three isozymes were identified. Both the tissue unspecific alkaline phosphatase and PLAP-like enzymes displayed relative increases of 10- to 100-fold and intestinal alkaline phosphatase 2- to 10-fold compared with normal testis. This finding indicates that the entire genome coding for alkaline phosphatases may be activated in seminomas. The PLAP-like enzyme from seminoma cells comprises a heterogenous population of molecules demonstrating partial heat sensitivity and microheterogeneity upon starch gel electrophoresis in contrast to the pregnancy related PLAP. These findings have implications for the different PLAP assays used in the clinical monitoring of seminoma patients.
 ...
PMID:Levels of alkaline phosphatase isozymes in human seminoma tissue. 364 91

HeLa S3 cells produce an alkaline phosphatase indistinguishable from the enzyme from human term placenta. The phosphatase activity in these cells was induced by both prednisolone and sodium butyrate. Both agents stimulated de novo synthesis of the enzyme. The increase in phosphatase activity paralleled the increase in immunoactivity and biosynthesis of placental alkaline phosphatase. The fully processed phosphatase monomer in control, prednisolone-treated or butyrate-treated cells was a 64.5 K polypeptide, measured by both incorporation of L-[35S]methionine into enzyme protein and active-site labeling. The 64.5 K polypeptide was formed by the incorporation of additional N-acetylneuraminic acid moieties to a precursor polypeptide of 61.5 K. However, this biosynthetic pathway was identified only in butyrate-treated cells. In prednisolone-treated cells, the processing of 61.5 K to the 64.5 K monomer was accelerated, and the presence of the 61.5 K precursor could only be detected by either neuraminidase or monensin treatment. Phosphatase mRNA which comigrated with the term placental alkaline phosphatase mRNA of 2.7 kilobases was induced in the presence of either prednisolone or butyrate. Alkaline phosphatase mRNA in untreated HeLa S3 cells migrated slightly faster than the term placental alkaline phosphatase mRNA. Butyrate also induced a second still faster migrating alkaline phosphatase mRNA. Both prednisolone and butyrate increased the steady-state levels of placental alkaline phosphatase mRNA. Our data indicate that the increase in phosphatase mRNA by prednisolone and butyrate resulted in the induction of alkaline phosphatase activity and biosynthesis in HeLa S3 cells. Furthermore, both agents induced the expression of different alkaline phosphatase gene transcripts without altering its protein product.
 ...
PMID:Control of placental alkaline phosphatase gene expression in HeLa cells: induction of synthesis by prednisolone and sodium butyrate. 365 99

Alkaline phosphatase activity in the liver and intestine increases after bile duct ligation, reportedly by increased enzyme synthesis. To ascertain the mechanism of this increased synthesis in the absence of a cDNA clone encoding the enzyme, we have estimated the concentration of liver and intestinal alkaline phosphatase mRNA by translational analysis. Monospecific antiserum to rat placental alkaline phosphatase was raised. The resulting antiserum precipitated two peptides of 53 and 56 kd after translation of liver poly(A) + RNA. The precipitation of both peptides was blocked by the single 64 kd placental alkaline phosphatase. Processing of the cell-free products by microsomal membranes produced peptides of 62 and 64 kd. Antiserum to rat intestinal alkaline phosphatase also identified two peptides as products of intestinal RNA translation. After bile duct ligation, we confirmed a transient 2-fold increase in alkaline phosphatase activity in the intestine and a more constant 7-fold increase in the liver. However, the alkaline phosphatase mRNA concentration remained unchanged in both organs. We conclude that increased alkaline phosphatase synthesis after bile duct ligation results from an enhanced rate of translation of mRNA.
 ...
PMID:The mechanism of elevated alkaline phosphatase activity after bile duct ligation in the rat. 371 Apr 26

Germinal neoplasms originating in the thalamus and basal ganglia were histologically verified by stereotactic biopsies in five cases and by other methods in three cases. Immunoperoxidase staining was performed on the tumors using antibodies against human chorionic gonadotropin and placental alkaline phosphatase. The presence of human chorionic gonadotropin was demonstrated in one germinoma and two mixed tumors, but not in three germinomas. Placental alkaline phosphatase was demonstrated to be present in four germinomas and one mixed tumor. Stereotactic biopsy specimens can be studied immunohistochemically, and the placental isoenzyme of alkaline phosphatase appears to be a new tumor marker for germinoma.
 ...
PMID:Diagnosis of germinal neoplasm in the thalamus and basal ganglia. 371 96

In the presence of methotrexate, cultured human choriocarcinoma (BeWo) cells undergo a differentiative response that resembles normal trophoblastic development. In the current study, the effects of cell number and population density on drug-induced conversion of BeWo cells from the cytotrophoblastlike to the syncytiotrophoblastlike phenotype were investigated using as markers of differentiation formation of "giant" cells, a process shown to require exogenous purines, and expression of placental (heat-stable) alkaline phosphatase. Giant cell formation, assessed by determination of cell volumes, was reduced in crowded cultures, and addition of hypoxanthine to growth media partially restored methotrexate-induced cell enlargement. Cellular uptake of methotrexate, assessed by following the loss of methotrexate from cell culture fluids during drug exposures, was two-threefold greater in sparsely populated than in densely populated cultures. Although the concentration of methotrexate in culture fluids of crowded cultures declined during exposures of 48 hr, the amount of extracellular drug remaining at 48 hr was well above the threshold for induction of the differentiative response. When culture population was held constant and population density was manipulated by varying the substratum available to cells, methotrexate-induced cell enlargement was inversely related to population density. Expression of placental alkaline phosphatase, salvage of exogenous hypoxanthine, and synthesis of RNA were also reduced at high population densities. These results indicate that expression of markers of methotrexate-induced differentiation of BeWo cells was inhibited in a density-dependent manner that may have been related to reduced cellular uptake of the inducing agent and of exogenous nutrients (purines) from culture fluids.
 ...
PMID:Density-dependent inhibition of expression of syncytiotrophoblastic markers by cultured human choriocarcinoma (BeWo) cells. 374 81

The microheterogeneity of Kasahara isozyme was investigated by affinity electrophoresis with Con A as the affinity ligand in combination with polyacrylamide gradient gel electrophoresis. On two-dimensional Con A-containing agarose gel electrophoresis, the Kasahara isozyme was separated into three molecular species. Kasahara isozyme electrophoresed as two distinct bands with enzyme activity on polyacrylamide gradient gel, but liver, intestinal or placental alkaline phosphatase showed only one distinct spot or band on both electrophoreses. One of the three molecular species of Kasahara isozyme separated by Con A-containing agarose gel electrophoresis was extracted from the gel and applied to the polyacrylamide gradient gel electrophoresis again, resulting in the same electrophoretic pattern as that of the original Kasahara isozyme. These findings indicated that the Kasahara isozyme consists of at least four molecular species. The same analysis was conducted with alkaline phosphatase of the HuH-6 cl-5 cell line, which has been reported to release an alkaline phosphatase closely resembling the Kasahara isozyme, and the results were compared with those obtained with the Kasahara isozyme.
 ...
PMID:Microheterogeneity of Kasahara isozyme. 375 65

A method for quantitating the liver, bone, intestinal and placental alkaline phosphatase activity of serum, using an algorithm for converting selective inactivation by guanidine hydrochloride, L-phenylalanine, and heat into equivalent isoenzyme activity is described. The method can individually quantify mixtures of isoenzymes to within a margin of 3%; it has acceptable reproducibility and has been used to develop both age and sex related reference ranges. Analysis time is about 30 minutes. The clinical reliability of this method has been shown in a study of 101 patients, in 79% of whom isoenzyme results were compatible with the final clinical diagnosis; in 10% a clinical diagnosis resulted from isoenzyme analysis, and in a further 11% the source of the increased alkaline phosphatase activity was identified and supported by electrophoresis, with a definite clinical diagnosis yet to be made.
 ...
PMID:Quantitative method for determining serum alkaline phosphatase isoenzyme activity II. Development and clinical application of method for measuring four serum alkaline phosphatase isoenzymes. 376 Feb 34

We have examined the effects of the "differentiating agent," sodium butyrate, on the induction of alkaline phosphatase in human colonic tumor cell line LS174T. Culture of these cells in the presence of 2 mM butyrate caused this activity to increase from less than 0.0001 unit/mg of protein to greater than 0.7 unit/mg of protein over an 8-day period. This induction proceeded in a nonlinear fashion with a lag time of 2-3 days occurring before enzymatic activity began to rise. These increases in activity were accompanied by elevations in the content of a placental-like isozyme of alkaline phosphatase as demonstrated by "Western" immunoblots. Dome formation, indicative of differentiation in cultured cells, also required 3 days treatment with butyrate before becoming evident. The rate of biosynthesis of the enzyme, examined using metabolic labeling with L-[35S]methionine and immunoprecipitation, was found to increase continuously between days 2 and 6 of butyrate treatment. "Northern" blot analysis indicated that treatment of these cells with butyrate caused greater than 20-fold induction of a 2700-base mRNA that hybridized to a cDNA probe for placental alkaline phosphatase. The mRNA for alkaline phosphatase produced by these cells upon butyrate treatment was approximately 300-400 bases smaller than the mRNA for alkaline phosphatase found in placenta. Human small intestine also contained two mRNAs that hybridized relatively weakly with the placental alkaline phosphatase probe. These results indicate that a placental alkaline phosphatase-like protein and mRNA are induced by butyrate in LS174T cells with a time course consistent with cellular differentiation preceding induction.
 ...
PMID:Effects of sodium butyrate on human colonic adenocarcinoma cells. Induction of placental-like alkaline phosphatase. 380 14


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>