Effect of human serum on alkaline phosphatase induction in cultured human tumor cells

The continuous cell lines T 24 and HT-29, derived from human bladder and colon carcinomas, produce term-placental and intestinal alkaline phosphatase, respectively. Growth in hyperosmolar medium or exposure to prednisolone or sodium butyrate induces increased enzyme levels, and combinations of inducers elicit synergistic activity increases. The effect of the inducing agents is strikingly diminished when cells are grown in the presence of high concentrations of human serum, and the synergistic increases are essentially abolished. Major human serum protein fractions do not affect alkaline phosphatase induction.     

Effect of human serum on alkaline phosphatase induction in cultured human tumor cells

Summary The continuous cell lines T 24 and HT-29, derived from human bladder and colon carcinomas, produce term-placental and intestinal alkaline phosphatase, respectively. Growth in hyperosmolar medium or exposure to prednisolone or sodium butyrate induces increased enzyme levels, and combinations of inducers elicit synergistic activity increases. The effect of the inducing agents is strikingly diminished when cells are grown in the presence, of high concentrations of human serum, and the synergistic increases are essentially abolished. Major human serum protein fractions do not affect alkaline phosphatase induction.     

Serum cholesterol levels in a Nigerian population sample

Serum cholesterol was determined in 104 healthy Nigerians (57 males and 47 females). The average cholesterol concentration was 187 +/- 72.8 mg/100 ml (mean +/- SD) with a range of 60-480 mg/100 ml. Cholesterol levels were higher in males than in females and increased with age. Distribution of cholesterol level was generally skew to the left.     

Serum cholesterol levels in a nigerian population sample

Summary Serum cholesterol was determined in 104 healthy Nigerians (57 males and 47 females). The average cholesterol concentration was 187±72.8 mg/100 ml (mean±SD) with a range of 60–480 mg/100 ml. Cholesterol levels were higher in males than in females and increased with age. Distribution of cholesterol level was generally skew to the left.Acknowledgment. I am grateful to Mr S. O. Oguike an Mr O. Uzoechi for technical assistance. I also thank Dr. E. O. Anosike for his help in arranging for the subjects of study.     

Activation and specificity of alkaline phosphatase of a mineralizing collagen-rich system

Summary Alkaline phosphatase from tibia tendon ofMeleagris gallopavo L. was highly purified. The enzyme activation by different ions was measured. Mg²⁺ showed a high activation with a broader spectrum of phosphomonoester hydrolization. The in vivo Mg²⁺ concentration was an optimum for in vitro activation.Dedicated to Prof. Dr. G. Pfefferkorn on the occasion of his 65^th birthday.We thank Deutsche Forschungsgemeinschaft for support.     

Activation and specificity of alkaline phosphatase of a mineralizing collagen-rich system

Alkaline phosphatase from tibia tendon of Meleagris gallopavo L. was highly purified. The enzyme activation by different ions was measured. Mg2+ showed a high activation with a broader spectrum of phosphomonoester hydrolization. The in vivo Mg2+ concentration was an optimum for in vitro activation.     

Histochemical response of alkaline phosphatase activity during the healing of cutaneous wounds in a cat-fish

Summary The activity of alkaline phosphatase in the various tissue components of the regenerating skin of a cat-fish has been studied. A marked increase in alkaline phosphatase activity in the cells of migrating epithelium has been correlated with their highly active state. High alkaline phosphatase in the basal cells after 2 days has been found to have played an important role in cell multiplication and differention. The functional significance of this enzyme is discussed in relation to the granulation tissue formation.     

Localisation of alkaline phosphatase in the development of the vertebral column in chick

Zusammenfassung Zu Beginn der Entwicklung der Wirbelsäure im Hühnerembryo findet sich die alkalische Phosphatase intrazellulär. Mit der späteren Verkalkung und Entwicklung des Knochenmarks ist die Reaktion extrazellulär nachweisbar.     

The indigogenic reaction for histochemical demonstration of alkaline and acid phosphatase

Résumé Le principe indigogénique à la détection histochimique des phosphates alcalins et acides a été appliqué. Ces substrates ont l'avantage de permettre une localisation précise de l'enzyme, sans ou avec minime diffusion. C'est aussi une méthode simple et directe pour la mise en évidence de ces enzymes sans passer par une réaction couplée. Un bisindigo très insoluble a lieu apparaît aux points d'activité enzymatique. Le 5-bromo-4-chlorocomposé donne un indigo bleu-vert tandis que le 5-bromo-6-chloro-composé donne un indigo magenta.     

An improved procedure for purification of alkaline phosphatase from rat kidney

Riassunto Viene descitto un nuovo metodo per la purificazione della fosfatasi alcalina da rene di ratto. La metodica comprende 4 tappe: (1) isolamento della frazione microsomiale; (2) solubilizzazione dell'enzima dalle strutture microsomiali per mezzo del desossicolato e della lipasi; (3) frazionamento cromatografico su DEAE-Sephadex A-25 ed eluzione con gradiente di concentrazione; (4) ricromatografia delle frazioni attive sullo stesso scambiatore anionico. All'elettroforesi su gel d'amido l'enzima ottenuto si comporta come una proteina omogenea.

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This work was supported by a grant from the Italian Consiglio Nazionale delle Ricerche, Impresa Enzimologia.     

The tyrosine phosphatase SHP-1 negatively regulates cytotrophoblast proliferation in first-trimester human placenta by modulating EGFR activation

Insulin-like growth factors (IGFs) influence placental cell (cytotrophoblast) kinetics. We recently reported that the protein tyrosine phosphatase (PTP) SHP-2 positively regulates IGF actions in the placenta. In other systems, the closely related PTP, SHP-1, functions as a negative regulator of signaling events but its role in the placenta is still unknown. We examined the hypothesis that SHP-1 negatively regulates IGF actions in the human placenta. Immunohistochemical (IHC) analysis demonstrated that SHP-1 is abundant in cytotrophoblast. SHP-1 expression was decreased in first-trimester placental explants using siRNA; knockdown did not alter IGF-induced proliferation but it significantly enhanced proliferation in serum-free conditions, revealing that placental growth is endogenously regulated. Candidate regulators were determined by using antibody arrays, Western blotting, and IHC to examine the activation status of multiple receptor tyrosine kinases (RTKs) in SHP-1-depleted explants; amongst the alterations observed was enhanced activation of EGFR, suggesting that SHP-1 may interact with EGFR to inhibit proliferation. The EGFR tyrosine kinase inhibitor PD153035 reversed the elevated proliferation seen in the absence of SHP-1. This study demonstrates a role for SHP-1 in human trophoblast turnover and establishes SHP-1 as a negative regulator of EGFR activation. Targeting placental SHP-1 expression may provide therapeutic benefits in common pregnancy conditions with abnormal trophoblast proliferation.     

The localization and functional significance of alkaline phosphatase in the vertebrate ovary

Zusammenfassung Es zeigt sich, dass die Wirkung der alkalischen Phosphatase in der Theca interna, im interstitiellen glandulären Gewebe und im Corpora lutea liegt und eine bedeutende Transportfunktion bei den ovariellen Zellmembranen der Wirbeltiere hat.     

Possible role of intestinal alkaline phosphatase activity in thiamine transport

Summary Thiamine deficiency caused a marked decrease of intestinal alkaline phosphatase (al-Pase) activity, but had no effect on the Ca⁺⁺-ATPase activity and Ca⁺⁺-absorption in rats. The al-Pase activity was significantly decreased 1 h after oral administration of ethanol at 0.5 and 2.5 g/kg. In contrast, Mg⁺⁺-, Ca⁺⁺- and (Na⁺+K⁺)-ATPase activities did not change after the administration of ethanol. These findings show that the al-Pase activity, unlike the Ca⁺⁺-ATPase activity, is not related to Ca⁺⁺-absorption. A possible role of al-Pase activity in the active transport of thiamine in the intestine was discussed.     

Localized areas of high alkaline phosphatase activity in the endothelium of arteries in the axolotl

Zusammenfassung Es werden lokalisierte Regionen von grosser alkalischer Phosphataseaktivität im Endothelium der Arterien beim Axolotl beschrieben.