PubMed Health⌕ Search

Biomedical subjects

L J Anghileri

Publications and source records attributed to L J Anghileri.

At least 19 recordsLinked to original sources
PubMed2005

Radiofrequency-induced carcinogenesis: cellular calcium homeostasis changes as a triggering factor.

The aim was to study the effects of radiofrequency (Rf) in a mice strain characterized by age-determined carcinogenesis of lymphatic tissues. Mice were treated with a 1?h/week Rf exposure for 4 months. A group submitted to sham exposure was used as control animals. The evolution of carcinogenesis was followed up to 18 months. The maximal life span of control mice was about 24 months. All dead animals were clinically and histologically examined to give an age-determined comparative quantification of the evolving carcinogenesis. A radiocalcium tracer method permitted the evaluation of Rf effects on transmembrane transport of extracellular calcium at 1 and 24 h after exposure. The determination of induced lipid peroxidation completed this second study. The findings show that Rf provoked an earlier general lymphocyte cell infiltration, formation of lymphoblastic ascites and extranodal tumours of different histological types, as well as an increased early mortality. The results suggest that in Rf-exposed mice, carcinogenesis may be induced earlier and with different pathological forms than in control animals. The modifications in cellular calcium homeostasis and the age-determined thymus involution appear to be important factors involved in this carcinogenesis process.

Animals↗
PubMed2000

Natural polyphenols-iron interaction: its biological importance.

The iron-binding capacity of different fractions of natural polyphenols extracts was determined by chromatographic and electrophoretic methods. Their effects on iron-induced calcium homeostasis changes in liver tissue suspension showed that mate tea and green tea extracts provoke a very significant inhibition of the iron effects, whereas it is much less significant with red wine extract. The biological importance of this phenomenon is discussed.

Adenosine Triphosphate↗
PubMed1998

Effects of low-molecular-weight aluminum complexes on brain tissue calcium homeostasis.

The in vitro effects of low-molecular-weight aluminum complexes (citrate, lactate, and ATP complex) on the Ca2+ uptake and aluminum-induced lipid peroxidation of brain tissue show that the modification of the calcium homeostasis is determined by the nature of the ligand and that there is no correlation between the aluminum-induced lipid peroxidation and the Ca2+ uptake. The same characteristics have been shown by a similar study performed with Ehrlich carcinoma cells. The electrophoretic analyses of the aluminum lactate-albumin and aluminum lactate-ATP interactions indicate an aluminum transfer from the lactate to the albumin and ATP ligands. The increased Ca2+ uptake when ATP is present in the incubation medium with aluminum citrate and aluminum lactate corroborates the suggested mediator role of ATP in cellular calcium homeostasis modification induced by iron.

Aluminum Compounds↗
PubMed1998

ATP in iron overload-induced intracellular calcium changes.

The cellular iron uptake from low molecular weight iron complexes (ferric citrate, ferric lactate and ferric ATP complex) is concentration-dependent, and only a small part of the iron penetrates the cell as shown by deferoxamine treatment. A threshold of iron concentration in the cell must be reached for the iron complex-induced increase of cellular Ca2+-uptake. ATP seems to play a key role in an iron translocation that enhances the effects of the iron complexes. A non-specific and competitive iron-binding by proteins seems to act as a buffer system that reduces the iron overload effects. Calcium channel blockers have no effects on the iron complex-cell interaction or iron-induced Ca2+-uptake modification. An iron complex concentration-dependent inhibition of the CaATPase activity, and its consequent Ca2+-extrusion impairment appear as the likely cause of calcium overload. The relevance of these findings in iron overload-induced pathologies is discussed.

Adenosine Triphosphate↗
PubMed1996

Role of lipid peroxidation in iron-induced cellular calcium overload.

Calcium overload is the common pathway leading to cell injury. The role of iron-induced lipid peroxidation in the modification of Ehrlich carcinoma cells calcium homeostasis has been studied. There is a lack of correlation between that modification and the value of lipid peroxidation. The stability characteristics of low-mol-weight iron complexes affect lipid peroxidation and, to a lesser extent, cellular calcium uptake. Lipid peroxidation appears not as a triggering factor of cellular calcium homeostasis modification, but as a concomitant phenomenon.

Adenosine Triphosphate↗
PubMed1995

Cardiotoxicity of parenterally administered iron complexes.

The role of cell calcium overload in the cardiotoxicity of low molecular weight iron complexes has been studied using 45Ca(2+)-uptake determinations in mice intraperitoneally injected with ferric lactate and ferric-ATP complex. Heart tissue shows a very high increase of 45Ca(2+)-uptake which appears to corroborate the hypothesis of cardiotoxicity by calcium overload. ATP seems to play a role in the degree of iron complex efficiency as cell calcium homeostasis modifier.

Adenosine Triphosphate↗
PubMed1994

Effects of albumin and adenosine phosphates on iron transfer from ferric lactate.

Ferric lactate is known to modify Ca2+ uptake by the cells. To enlighten the role of protein and ATP in this phenomenon, iron transfer from ferric lactate to albumin and adenosine polyphosphates was determined by electrophoresis. The order of iron affinity was ATP > ADP > AMP for the polyphosphates, and albumin does not compete for iron binding with the polyphosphates. The iron transfer to ATP was also observed in vivo by adsorption chromatography of the adenosine polyphosphates fraction from blood plasma of mice injected with ferric lactate plus ATP. In vitro iron and calcium uptake by Ehrlich ascites tumor cells showed that albumin and ATP decreased iron uptake, whereas calcium incorporation is diminished by albumin but augmented by ATP. This difference might be explained by albumin binding of ferric lactate that is inhibited from reaching cell structures, whereas ATP, known to be an inhibitor of iron polymerization, facilitates it.

Adenine Nucleotides↗
PubMed1994

Liver calcium homeostasis modification by iron: a probable factor in its carcinogenesis.

Low molecular weight iron complexes, ferric lactate and ferric-ATP complex, induce an important increase of Ca(2+)-uptake by liver. The activity of ferric lactate increased by the presence of sodium ATP, and the steady high effect of ferric-ATP complex appear to indicate that ATP might play an important role in the in vivo formation of low molecular weight iron complexes that can induce the modification of the hepatocytes calcium homeostasis, the event that might be one of the factors triggering the malignant transformation.

Adenosine Triphosphate↗
PubMed1993

On the mechanism of soft tissue calcification induced by complexed iron.

The interaction of ferric lactate with Ehrlich carcinoma ascites cells induces a modification of Ca(2+)-uptake which is in direct relationship with the iron mass bound to the cells. Competitive binding of iron by deferoxamine indicates that only a part of the bound iron penetrates the cell, and that to trigger a Ca(2+)-influx this intracellular iron must be over a threshold concentration. The experimental finding that ferric lactate transfers its iron to albumin and to ATP suggests that in the Ca(2+)-uptake modification it works through its iron transfer which provokes the inhibition of the cell calcium homeostasis regulatory systems (Ca(2+)-channels, intracellular Ca(2+)-binding sites and Ca(2+)-pump ATPase). The involvement of ATP in the action of ferric lactate seems related to a higher stability of the complex, and to a larger availability of active iron able to perform the inhibitory process.

Animals↗
PubMed1992

Changes in calcium uptake by liver induced by ferric lactate.

In vitro and in vivo Ca(2+)-uptake by the liver is increased by ferric lactate. In vitro albumin and deferoxamine inhibit ferric lactate effects. Electrophoresis demonstrates the binding of ferric lactate to albumin. In vivo, ferric lactate induces a significant increase of Ca(2+)-uptake by liver, with a maximum of 2.9 nmol/g against 0.66 nmol/g for control livers (P less than 0.005) between 5 and 24 h after administration. This uptake modification is reversible, while the amount of iron (measured as 59Fe taken up) remains constant throughout the experiment. The affinity of ferric lactate for protein and the iron mass-dependence of Ca(2+)-uptake increase support for the hypothesis of a ferric lactate-cell membrane interaction rather than an iron-catalyzed cell injury by lipid peroxidation as the major event leading to an increased Ca(2+)-uptake.

Animals↗
PubMed1992

Soft tissue calcification induced by iron complexes.

Complexed iron (III) induces a local calcification of soft tissues in mice that is strongly dependent upon the nature of the complexing molecule. Ferric lactate is much more effective in inducing calcification than iron dextran.

Animals↗
PubMed1992

Ehrlich tumour cells: Ca(2+)-uptake modification by aluminium lactate.

Aluminium lactate provokes the same modification of 45Ca(2+)-uptake by Ehrlich ascites tumour cells as does ferric lactate. The increase of uptake is metal-complex concentration-dependent, and in contrast to ferric lactate, is only partially inhibited by albumin. Under the same experimental conditions, chromic lactate provoked no modification of that uptake. A plasma membrane rigidity increase provoked by coordination binding of aluminium to phospholipids is likely to be the main cause of Ca(2+)-uptake modification by aluminium lactate.

Animals↗
PubMed1992

Effects of complexed iron and aluminium on brain calcium.

Ferric lactate increases Ca(2+)-uptake by Ehrlich carcinoma ascites cells as well as in vitro and in vivo Ca(2+)-uptake by the liver. Iron and aluminium are increased in the substantia nigra of patients with Parkinson's disease and aluminium is suspected to be involved in the pathophysiology of Alzheimer's disease. This study was conducted to determine if there is any relationship between iron and aluminium uptake and a possible calcium influx into brain tissue. Groups of Swiss mice were injected in the tail vein with 100 microliters of 0.05 M ferric lactate plus 2 microCi45CaCl2, or 100 microliters of 0.05 M aluminium lactate plus 2 microCi45CaCl2, or 100 microliters of saline plus 2 microCi45CaCl2. Twenty-four hr later they were sacrificed by decapitation. Samples of blood and the total brain were weighed and ashed. The ashes were dissolved and the solution transferred to counting vials evaporated to dryness. A scintillation solution was added to the vials and the radioactivity was counted. To accurately assess brain uptake in each animal the value of brain specific activity was related to blood specific activity. When compared to those of control animals, these values gave the 24 hr increase of 45Ca-uptake by brain of ferric lactate or aluminium lactate-treated animals. A significant increase of 45Ca-uptake was observed for ferric lactate (136% of control value, p less than 0.005), which is more important for aluminium lactate (163% of control value, p less than 0.001). The nature of the complexed metal-brain tissue interaction is not known, several mechanisms are discussed.

Animals↗
PubMed1992

Iron-tumor cell interaction and regulation of Ca2+ homeostasis: their implication in tumor growth.

Using [59Fe] ferric lactate, a direct relationship between iron concentration and [59Fe] uptake by Ehrlich ascites tumor cells was found. Deferoxamine and albumin inhibited this uptake. Electrophoresis showed that both molecules complexed iron from ferric lactate. [45Ca] uptake in the presence of ferric lactate showed the same inhibition, and an iron mass-dependence, these findings suggest an iron--cell membrane interaction as the cause of this phenomenon. The implication of iron--tumor cell membrane interaction in tumor growth regulation is discussed.

Animals↗
PubMed1991

Effects of Fe(3+)-tumor cell interaction on Ca(2+)-uptake by Ehrlich ascites tumor cells.

Fe3+ ions complexed by various ligands induce an increased Ca2+ uptake by Ehrlich carcinoma ascites cells that is proportional to the thermodynamic stability constant of the complex, and the greatest increase is observed with ferric lactate. The absence of ATPase inhibition showed by this ferric complex, suggests that an increased passive diffusion of Ca2+ due to structural modifications of the cell membrane is the most probable cause of this phenomenon.

Animals↗
PubMed1991

Cell labelling with 67Ga-citrate.

A method of cell labelling with carrier-free 67Ga-citrate, based on a co-binding with iron from ferric lactate has been developed. 67Ga-binding has a direct relationship with the iron incorporation by the cell. Using this method Ehrlich ascites tumor cells increase their uptake from 5% (no ferric lactate) to 89% (5 mumol of ferric lactate). Erythrocytes have shown the same pattern of 67Ga-binding. In vivo cytotoxic assays (ascites formation and animal survival) have demonstrated the lack of cytotoxicity of ferric lactate under these experimental conditions. Electrophoretic analyses of 67Ga-labelled tumor cells and erythrocytes have shown the absence of free 67Ga-citrate.

Adult↗
PubMed1991

The role of the interaction between Fe(III) and cell surface in the accumulation of 67Ga by tumor cells.

The study of the interaction between complexed iron and tumor cells in the presence of 67Ga-citrate indicates that a phenomenon of iron-binding related to the thermodynamic constant of stability of the iron complex, and a hydrolysis (or anion penetration) of the interaction product determine the uptake of 67Ga. The effects of various parameters such as ionic composition of the medium, nature of the iron complex, time of incubation and number of cells are discussed.

Animals↗