Alkaline phosphatase

About: Alkaline phosphatase is a research topic. Over the lifetime, 20218 publications have been published within this topic receiving 540547 citations. The topic is also known as: Alkaline_phosphatase & IPR001952.

Role of alkaline phosphatase in colitis in man and rats

Abstract: Background & Aims: Crohn9s disease (CD) and ulcerative colitis (UC) are chronic multifactorial inflammatory bowel diseases with unknown etiology, but a deregulated mucosal immune response to gut-derived bacterial antigens is thought to be involved. Toll-like receptor ligands, especially lipopolysaccharide (LPS), contribute to the maintenance of the disease. We have previously shown that the enzyme alkaline phosphatase (AP) is able to detoxify LPS and the aim of this study was to examine a possible role in inflammatory bowel diseases. Methods: Intestinal AP (iAP) mRNA expression and LPS-dephosphorylation in intestinal biopsies of control persons and IBD patients were examined, and we subsequently studied the effect of orally administered iAP-tablets on the progression of dextran sodium sulphate-induced colitis in rats. Results: In healthy persons, iAP mRNA and enzyme activity was high in the ileum relative to the colon. In UC and Crohn9s patients iAP mRNA expression was found markedly reduced when inflamed tissue was compared to non-inflamed tissue. Oral administration of iAP-tablets to colitic rats resulted in a significant attenuation of colonic inflammation as reflected by reduced mRNA levels for TNFα, IL-1β, IL-6 and iNOS, a reduced iNOS-staining and inflammatory cell influx, and a significantly improved morphology of the intestinal wall. Conclusions: The present study shows that epithelial iAP mRNA expression is reduced in both UC and Crohn9s patients. The rat model demonstrates that oral administration of active iAP-enzymes in the intestinal tract, results in a significant reduction of inflammation. This provides new insight on IBD pathology and a novel treatment approach to this severe inflammatory disease.

Effects of an injectable platelet-rich fibrin on osteoblast behavior and bone tissue formation in comparison to platelet-rich plasma

Abstract: Platelet-rich plasma (PRP) has been utilized for many years as a regenerative agent capable of inducing vascularization of various tissues using blood-derived growth factors. Despite this, drawbacks mostly related to the additional use of anti-coagulants found in PRP have been shown to inhibit the wound healing process. For these reasons, a novel platelet concentrate has recently been developed with no additives by utilizing lower centrifugation speeds. The purpose of this study was therefore to investigate osteoblast behavior of this novel therapy (injectable-platelet-rich fibrin; i-PRF, 100% natural with no additives) when compared to traditional PRP. Human primary osteoblasts were cultured with either i-PRF or PRP and compared to control tissue culture plastic. A live/dead assay, migration assay as well as a cell adhesion/proliferation assay were investigated. Furthermore, osteoblast differentiation was assessed by alkaline phosphatase (ALP), alizarin red and osteocalcin staining, as well as re...

Ontogeny of enzymatic activities in fed and fasting turbot, Scophthalmus maximus L.

Abstract: The presence and localization of acid and alkaline phosphatase, non-specific proteases, aminopeptidase, amylase, non-specific esterase and lipase was investigated by histoenzymologic methods in fed and fasting turbot from day 1 to day 40 post-hatching and compared with published data. Alkaline phosphatase and aminopeptidase activities were delected at day 1 in the distal region of the developing digestive tube. At day 3 (opening of the mouth) aminopeptidase and alkaline phosphatase activities were found all along the intestine. Sites of non-specific esterase and protease activities became apparent in the digestive tract at days 2 and 3 respectively. Amylase was present in the exocrine pancreas at day 3 and in the lumen of the intestine at day 4. Acid phosphatase was active in the cellular structure surrounding the yolk stores and in the lipid droplets at day 1 and in the intestinal epithelium at day 3. Lipase was found at day 15 when the larvae metamorphose into juveniles. All the investigated enzymes were detected in fasting animals, except for lipase. However, the intensities of the enzymatic activities were weaker in the fasting specimens relative to the fed specimens between days 7 and 10.

Expression of a human placental alkaline phosphatase gene in transfected cells: use as a reporter for studies of gene expression

Abstract: The human placental alkaline phosphatase gene has been cloned and reintroduced into mammalian cells. When a plasmid carrying the gene under control of the simian virus 40 early promoter (pSV2Apap) is transfected into a variety of different cell types, placental alkaline phosphatase activity can readily be detected by using whole cell suspensions or cell lysates. Alkaline phosphatase activity can also be visualized directly in individual transfected cells by histochemical staining. The gene is appropriate for use as a reporter in studies of gene regulation since its expression is dependent on the presence of exogenous transcription control elements. The overall assay to detect the expression of the gene is quantitative, very rapid, and inexpensive. Cotransfections of cells with pSV2Apap and a related plasmid carrying the bacterial chloramphenicol acetyltransferase gene (pSV2Acat) indicate that transcription of these two genes is detected with roughly the same sensitivity.

Granulocytic leukaemia in childhood.

Abstract: GRANULOCYTIC leukaemia is uncommon in childhood. Eisenberg and Wallerstein found 3 0 cases in the literature up to 1934, and reports of about another IOO cases have appeared since then. Most of those authors who have reported on the relative incidence of the condition have found it to lie between 2 and 5 per cent of all cases of childhood leukaemia (e.g. Cooke, 1953 ; Barrett, Conrad and Crosby, 1960; Lightwood, Barrie and Butler, 1960; Bernard, Seligman and Acar, 1962; Reisman and Trujillo, 1963). Several authors have noted that the disease seen in infants and young children differs in certain respects from that of older children, in whom it usually closely resembles chronic granulocytic leukaemia of adults. Thus Cooke (1953) drew attention to the frequency of thrombocytopenia and the shorter course in infants, while Vahlquist and Vuille (1960) also noted their increased susceptibility to infections and their relatively high lymphocyte counts. Bernard et al. (1962) classify the form seen in young children as myelomonocytic leukaemia, and regard it as a separate entity from the chronic myeloid leukaemia of older children and adults ; they stress the early onset of thrombocytopenia and lymph node enlargement as features particularly characteristic of the myelomonocytic type of leukaemia, which is usually characterized by a lower total leucocyte count, with fewer myelocytes, but a higher proportion of monocytes than is commonly found in adults. This concept of the juvenile and adult types as two distinct forms of leukaemia has recently received strong support from the work of Reisman and Trujillo (1963), who found the Philadelphia (Phl) chromosome in bone-marrow cells of five children whose disease resembled chronic myeloid leukaemia of adults, but in none of four young children with the juvenile type, all of whom had marked lymph node enlargement and thrombocytopenia at the onset of their disease. Our object here is to present four cases of each of these types of granulocytic leukaemia in children, and to compare and contrast their clinical, haematological and cytogenetic features.