Search results for "PHOSPHATE"

Calorimetric investigation of the precipitation of calcium monohydrogen phosphate in water/AOT/n-heptane microemulsions

2000

Abstract The molar enthalpies of precipitation of calcium monohydrogen phosphate (CaHPO 4 ) in water/sodium bis(2-ethylhexyl) sulfosuccinate (AOT)/ n -heptane microemulsions were measured at 25°C by a calorimetric technique as a function of the molar ratio R ( R  = [water]/[AOT]) at a fixed AOT concentration. Calorimetric data indicate the formation of CaHPO 4 nanoparticles encapsulated in the aqueous core of the AOT reversed micelles displaying a slow growing process with time. Their energetic state is initially different from that in bulk water approaching the value in water at longer times. The observed growing process results to be completely inhibited by the presence of small amounts o…

6-Phosphofructokinase from frog skeletal muscle: purification and properties

1990

Osmotic conditions in rheologic properties of erytrocites

2001

Abstract The decreasing viability and in vivo survival of red blood cells, RBCs, observed in blood bank-storage are due to alterations in their rheologic properties and metabolic status. However, there is a lack of electrokinetic experiments with erythrocytes by the screening produced by the high concentration of buffer required to keep the isoosmotic conditions. Electrokinetic measurements in a wide range of sodium chloride and tetrasodium pyrophosphate are undertaken on liposomes as cell models, and in order to get an aqueous media suitable for maintaining osmotic conditions and allowing electrophoretic mobility measurements as well, advantage has been taken of dextrose properties. Measur…

Biomimetic routes to micro/nanofabrication

2020

Abstract The discovery of inorganic polyphosphate (polyP), an evolutionarily ancient biopolymer, and of its function in energy storage/supply and induction of cell differentiation through specific gene expression (“morphogenetic activity”) has opened new opportunities in regenerative medicine, including therapy of bone, cartilage, and vascular diseases. Inspired by nature, various procedures have been developed for the preparation of amorphous nano and microparticles of polyP with different counterions, which mimic the physiological polyP found in blood platelets/acidocalcisomes, as well as for the preparation of morphogenetically active polyP coacervate complexes. This chapter summarizes t…

Breakdown of high-energy phosphate compounds and lactate accumulation during short supramaximal exercise.

1987

Muscle ATP, creatine phosphate and lactate, and blood pH and lactate were measured in 7 male sprinters before and after running 40, 60, 80 and 100 m at maximal speed. The sprinters were divided into two groups, group 1 being sprinters who achieved a higher maximal speed (10.07 +/- 0.13 m X s-1) than group 2 (9.75 +/- 0.10 m X s-1), and who also maintained the speed for a longer time. The breakdown of high-energy phosphate stores was significantly greater for group 1 than for group 2 for all distances other than 100 m; the breakdown of creatine phosphate for group 1 was almost the same for 40 m as for 100 m. Muscle and blood lactate began to accumulate during the 40 m exercise. The accumulat…

Autophagy, cathepsin L transport, and acidification in cultured rat fibroblasts.

1992

The mechanisms of enzyme delivery to and acidification of early autophagic vacuoles in cultured fibroblasts were elucidated by cryoimmunoelectron microscopic methods. The cation-independent mannose-6-phosphate receptor (MPR) was used as a marker of the pre-lysosomal compartment, and cathepsin L and an acidotropic amine (3-(2,4-dinitroanilino)-3'-amino-N-methyl-dipropylamine (DAMP), a cytochemical probe for low-pH organelles) as markers of both pre-lysosomal and lysosomal compartments. In addition, cationized ferritin was used as an endocytic marker. In ultrastructural double labeling experiments, the bulk of all the antigens was found in vesicles containing tightly packed membrane material…

A cytochemical study on the effects of energy deprivation on autophagocytosis in Ehrlich ascites tumor cells

1988

The effect of energy deprivation on autophagocytosis in Ehrlich ascites tumor cells was studied using cytochemical techniques. Autophagocytosis was induced with vinblastine incubation (0.1 mM) and the cellular ATP-level was lowered with 2-deoxy-D-glucose (0.35 mM). Acid phosphatase was used as a marker for lysosomal enzymes and imidazole-buffered osmium tetroxide impregnation in order to study the effects of energy deprivation on the maturation of autophagic vacuole (AV) membranes. Control and vinblastine treated cells maintained their ATP-levels throughout the incubation period tested (120 min). 2-Deoxy-D-glucose alone and with vinblastine decreased the intracellular ATP-level significantl…

In vivo detection of cytokeratin filament network breakdown in cells treated with the phosphatase inhibitor okadaic acid.

2001

We have previously described vulva carcinoma-derived A-431 subclone AK13-1, which stably expresses fluorescently labeled cytokeratin filaments (CKFs). Time-lapse fluorescence microscopy of these cells permits the continuous monitoring of the dynamics of the CKF cytoskeleton in vivo. To study mechanisms and principles of CKF disassembly as it occurs, e.g., during mitosis and liver disease, we have treated cells with the phosphatase inhibitor okadaic acid (OA), which induces complete CKF network breakdown within 3–5 h without significantly affecting the organization of the actin- and tubulin-based cytofilaments. In time-lapse movies, we find that the network breakdown starts at the cell perip…

Effect of cooking and legume species upon calcium, iron and zinc uptake by Caco-2 cells

2006

Abstract An in vitro system, consisting of simulated gastrointestinal digestion and Caco-2 cell culture, was used to estimate the uptake of calcium, iron and zinc from white beans, chickpeas and lentils, and the effect of cooking upon uptake, with the ultimate aim of evaluating legumes as a dietary source of the aforementioned minerals. In raw products, differences were observed in the uptake percentages by Caco-2 cells of a same mineral from different legumes, although these were not related to the total mineral content. In the three elements studied, the highest uptake values corresponded to chickpeas. Traditional cooking significantly ( p 0.05 ) increased the uptake (%) of calcium, iron …

Combined study of anion recognition by a carbazole-based neutral tripodal receptor in a competitive environment

2012

Anion recognition studies have been carried out on a series of neutral synthetic receptors in which carbazole-2-carboxamide has been used as building block. Different ligands which include one to three carbazole units in their structure have been prepared. Binding experiments have been performed under competitive conditions in DMSO and DMSO-water solutions. The tripodal receptor offered a better host-guest association due to the synergistic effect of a well arranged set of hydrogen bonds. A selective response towards the biologically important pyrophosphate anion has been achieved. This selectivity is enhanced when studies are carried out with an increasing water content, which gets as high…