The determination of Al, Cr, Co, Fe, and Ni in whole blood by electrothermal atomic absorption spectrophotometry

Procedures for the determination of aluminum, chromium, cobalt, nickel, and iron in whole blood are presented and discussed. Chromium, cobalt, nickel, and iron were determined from one sample after decomposition of the blood with a mixture of nitric and perchloric acids. A graphite furnace was used for the determination of chromium, cobalt and nickel, and flame AAS was used for iron. The determination of Al was done from separate samples by GFAAS after dilution with 1% Triton TX-100. The normal concentration of these elements was measured in rabbit and dog blood.     

Release of metal ions from dental implant materials in vivo: determination of Al, Co, Cr, Mo, Ni, V, and Ti in organ tissue.

Little is known of the release of trace elements in vivo from dental implant materials. Conflicting data have been reported in the literature as to the levels of trace elements released and their potential consequences, mainly because of sampling and analytical methodological errors. In this study methods for average concentration levels of Al, Cr, Co, Mo, Ni, Ti, and V in organs were developed using rabbit tissue from an in vivo implantation study. At least 50% of the brain, liver, lung, kidney, and spleen were taken minimizing contamination. The tissue was homogenized by cryogenic milling at LN2 temperature and then freeze-dried. Samples were digested in nitric acid and hydrogen peroxide using microwave energy. Standard reference materials were utilized for quality control. One liver sample was analyzed 10 times to assess the method precision. Absorbance values in blanks, standards, and test samples were measured using a Varian GTA 95 graphite furnace and 875 spectrophotometer. Very satisfactory method precision and quality control were recorded. Low or very low levels of the trace elements were found in the various organs.     

The electrochemical behavior and surface analysis of Ti49.6Ni45.1Cu5Cr0.3 alloy for orthodontic usage

The aim of this study was to investigate the electrochemical behavior of Ti(49.6)Ni(45.1)Cu(5)Cr(0.3) (TiNiCuCr) alloy in artificial saliva solutions with a wide rage of pH values and to characterize the surface passive film after polarization tests. This article represents the ideal, static environment and associated electrochemical response and comparison values. The corrosion behavior of TiNiCuCr alloy was systematically studied by open circuit potential, potentiodynamic, potentiostatic, and electrochemical impedance techniques. Potentiodynamic and potentiostatic test results showed that the corrosion behavior of TiNiCuCr was similar to that of NiTi alloy. Both corrosion potential (E(corr)) and pitting corrosion potential (E(b)) showed a pH-dependent tendency that E(corr) and E(b) decreased with the increase of the pH value. X-ray photoelectron spectroscopy results revealed the composition of the passive film consisted mainly of TiO(2) with a little amount of Ni oxides (NiO/Ni(2)O(3)) that was identical with NiTi alloy. Besides Ni, a Cu enriched sub-layer was also found. The nickel ion release rate showed a typical time-related decrease as examined by ICP/OES. In conclusion, the addition of Cu and Cr had little effect on the corrosion behavior of NiTi or on the composition and the structure of the passive film.     

Copolymerization of styrene with Zn(II), Co(II), Ni(II) and Cu(II) acrylates

The radical copolymerization of styrene with Zn(II), Co(II), Ni(II) and Cu(II) acrylates in methanol at 60°C was studied and that of styrene with Cu(II) acrylate also in acetonitrile at 80°C. In a given period of time an increase of conversion was observed with increasing concentration of the first three metal acrylates in mixtures with styrene. With Cu(II) acrylate, however, a decrease of conversion was found. The monomer reactivity ratios were determined as follows: r_St = 1,10, r = 0,90; r_St = 1,74, r = 0,56; r_St = 1,83, r = 0,53; r_St = 5,94, r = 0,12 (in acetonitrile). The products of the reactivity ratios, almost equal to one, reflect an “ideal” copolymerization and therefore a very little alternating tendency in propagation reactions. The Alfrey-Price Q-e parameters for the metal acrylates were calculated and discussed.     

Analysis of metal ion-induced DNA damage, apoptosis, and necrosis in human (Jurkat) T-cells demonstrates Ni2+ and V3+ are more toxic than other metals: Al3+, Be2+, Co2+, Cr3+, Cu2+, Fe3+, Mo5+, Nb5+, Zr2+

It remains unclear how metal released from implants affects cells of the immune system and, in particular, cells of the adaptive immune system, that is, T-helper lymphocytes. In this study, we investigated the effects of aluminum, chromium, cobalt, copper, iron, molybdenum, nickel, niobium, vanadium, and zirconium ions at concentrations from 0.05 to 5.0 mM on human CD4+ T lymphocytes. The DNA damage, apoptosis, necrosis, and proliferation responses of a human T-helper lymphocyte (Jurkat) cell line were evaluated to test our hypothesis that some metals will preferentially induce genotoxicity (DNA damage). Our results demonstrated that metal ions did not preferentially induce Jurkat T-lymphocyte DNA damage prior to other forms of toxicity, that is, apoptosis and/or direct necrosis. Nickel and vanadium induced the most DNA damage and were the most apoptotic metals tested, inducing >50% caspase-9 positive T cells at 0.05 mM and 0.1 mM concentrations, respectively. Cobalt and niobium were the most toxic metals, inducing <50% viability at approximately 0.5 mM concentrations. Nickel and vanadium were the only metals to induce DNA damage at nearly the same concentrations that induced >50% apoptosis (i.e., <0.05 mM). All the metals tested induced T-cell apoptosis at a lower dose than that required to affect DNA damage or toxicity, implying that soluble metals released from implants may not be preferentially genotoxic to lymphocytes.     

Effects of Certain Cations (Fe, Zn, Mg, and Ca) on Bacterial Endotoxins

The natural occurrence of cations Fe, Zn, Mg, and Ca in the lipopolysaccharide (LPS) of both the S and R forms of Shigella dysenteriae 1 was studied. LPS preparations were obtained either by phenol-water extraction (according to the method of Westphal et al., Z. Naturforsch. 7b:148-155, 1952) or by extraction of cells with hypertonic sodium chloride-sodium citrate (according to the method of Raynaud and Digeon, C. R. Acad. Sci. (Paris) 229:564-566, 1949), with subsequent chromatographic purification on Sephadex G200 and Sepharose 4B columns. The cation in highest concentration in the Westphal extract was Mg(2+) (as much as 30 mug/mg), and the lowest one was Fe (ca. 0.10 mug/mg). In LPS of the Raynaud type, the cation in highest concentration was Ca(2+) (as much as 13 mug/mg), and the lowest one was Fe (ca. 0.10 mug/mg). The effects of increasing and decreasing the concentrations of cations (Fe, Zn, Mg, Ca) upon the biological activity of the endotoxins was evaluated by using toxicity in mice and the Limulus test. It appeared that increased concentrations of Fe (chiefly of Fe(3+)) decreased the toxicity of the R form of LPS, whereas Mg(2+) decreased the toxicity of the S form. After prolonged dialysis of LPS preparations against deionized water, there was no consistent relationship between toxicity as determined in white mice and with the Limulus test.     

Photodynamic action of Tri-meso (N-methyl-pyridyl), meso (N-tetradecyl-pyridyl) porphine on Staphylococcus epidermidis biofilms grown on Ti6Al4V alloy

Staphylococcus epidermidis is a leading cause of nosocomial infections, and its virulence is attributable to formation of biofilm, especially on implanted devices. Photodynamic treatment (PDT) has been actively investigated for the eradication of bacterial biofilm growing on dental plaques and oral implants. In this study, we used Tri-meso (N-methyl-pyridyl), meso (N-tetradecyl-pyridyl) porphine (C14) for inactivation of two structurally distinct S. epidermidis biofilms grown on Ti6Al4V alloy and compared its photosensitizing efficiency with that of the parent molecule, tetra-substituted N-methyl-pyridyl-porphine (C1). A more significant reduction in bacterial survival was observed when both bacterial biofilms were exposed to a lower dose of C14, and simultaneously to visible light in comparison with C1. The different responses of both staphylococcal biofilms to C1- or C14-treatment appeared to depend on photosensitizer endocellular concentration. C14 bound to both biofilms to a greater extent than C1. Moreover, C14 penetrates deeper into the bacterial membranes, as determined by fluorescence quenching experiments with methylviologen, allowing for better bacterial killing photoefficiency. Confocal laser scanning microscope (CLSM) analysis indicated damage to bacterial cell membranes in both photodynamically treated biofilms, while disruption of PDT-treated biofilm was confirmed by scanning electron microscopy (SEM). In summary, C14 may be a potential photosensitizer for the inactivation of staphylococcal biofilms for many device-related infections which are accessible to visible light.     

Effect of heavy metals (Cu, Cd and Pb) on aspartate and alanine aminotransferase in Ruditapes philippinarum (Mollusca: Bivalvia)

The accumulation of cadmium, copper and lead and their effects on aspartate and alanine aminotransferases in digestive gland, gills, foot and soft body in the clam Ruditapes philippinarum were examined. The animals were exposed to different concentrations: Cd (200-600 micrograms.l-1), Pb (350-700 micrograms.l-1) and Cu (10-20 micrograms.l-1) for 7 days. The highest concentrations were found in digestive gland for cadmium and copper, and in gills for lead, and the lowest values were observed in the foot. Aspartate aminotransferase activity (AST), in general, was not inhibited by cadmium, lead or copper during the exposure. Only in clams exposed to cadmium (600 micrograms.l-1, 7 days) and copper (20 micrograms.l-1, 5 days) were observed significant differences (P < 0.05) in foot and gills, respectively, with respect to control. In the case of alanine aminotransferase activity (ALT), significant differences were observed for cadmium and lead in treated animals with respect to control. With regard to copper, a decrease in ALT was observed in gills and foot exposed to 20 micrograms.l-1. A significant correlation (P < 0.05) was observed between ALT and metal accumulation for cadmium, copper and lead in gills. In the case of soft body, only cadmium and lead showed a significant correlation. In summary, R. philippinarum can be considered a bioindicator species for cadmium and lead accumulation and ALT could be useful as biomarker of sublethal stress for these metals in soft tissues and gills can be considered an adequate target tissue for copper.     

Quantitative Investigation of the Electronic and Steric Influences on Ethylene Oligo/Polymerization by 2‐Azacyclyl‐6‐aryliminopyridylmetal (Fe,Co, and Cr) Complexes

The multiple linear regression analysis is performed to investigate both electronic and steric effects of ligands on the catalytic activities of the transition metal complexes in ethylene oligo/polymerization. The Hammett constants (F) and effective net charge (Q) are used to describe the electronic effect, meanwhile the steric effect is illustrated by open cone angle (θ) and bite angle (β). Four series of 2‐azacyclyl‐6‐aryliminopyridylmetal (Fe, Co, and Cr) analog complexes are calculated and the catalytic activity can be efficiently analyzed through taking both the electronic and steric effects into account. All of the obtained correlation coefficient R ² values are over 0.93. The electronic effect is dominant in determining the catalytic activities for Fe and Co complexes; however, the steric effect plays a major role in controlling activities of Cr complexes.

     

Microstructures and mechanical properties of metastable Ti-30Zr-(Cr, Mo) alloys with changeable Young's modulus for spinal fixation applications

In order to develop a novel alloy with a changeable Young's modulus for spinal fixation applications, we investigated the microstructures, Young's moduli, and tensile properties of metastable Ti-30Zr-(Cr, Mo) alloys subjected to solution treatment (ST) and cold rolling (CR). All the alloys comprise a β phase and small athermal ω phase, and they exhibit low Young's moduli after ST. During CR, deformation-induced phase transformation occurs in all the alloys. The change in Young's modulus after CR is highly dependent on the type of deformation-induced phase. The increase in Young's modulus after CR is attributed to the deformation-induced ω phase on {3 3 2} mechanical twinning. Ti-30Zr-3Cr-3Mo (3Cr3Mo), which exhibits excellent tensile properties and a changeable Young's modulus, shows a smaller springback than Ti-29Nb-13Ta-4.6Zr, a β-type titanium alloy expected to be useful in spinal fixation applications. Thus, 3Cr3Mo is a potential candidate for spinal fixation applications.     

The action of phosphotriose,phospho-enolpyruvic acid and the preparation ZSC (zymostimulator cordis) on cardiac muscle

Summary Preparations of the sodium salt of triose phosphate, obtained by biochemical means, as well as those of the sodium salt of phospho-enolpyruvic acid (PEP) obtained both biochemically and by chemical synthesis were studied in respect to their action upon the fatigued frog's heart (by Straub's method). Synthetic PEP was found to be inactive, while triose phosphate and biochemically obtained PEP exercise a stimulating effect on the heart similar by its character and its effective dose to the action of the sodium salt of fructose-1,6-diphosphate (DPF).Treatment of triose phosphate preparations (obtained biochemically) and those of PEP with charcoal at various pH, and their subsequent examination along with that of the eluted fluid (wash off) were investigated. It was demonstrated that the action of the preparations on the fatigued heart is, at least in its main part, associated with the presence of the low quantities of zymostimulator cordis (ZSC) as admixture. ZSC is a uridine derivative close or identical to uridinediphosphate (UDP) formerly isolated by the authors from yeast and sodium-DPF preparations.Presented by Active Member AMN SSSR S. E. Severin     

Mechanism of action of alloxan on pancreatic B-cells with special regard to the alloxan-metal-complex theory. II. Actions of alloxan, alloxanic acid, Zn2+ and ethyleneglycol-bis-(beta-aminoethylether)-N,N'tetraacetic acid (EGTA) on the assembly of microtubule proteins (MTP) into microtubules or MPT sheets in vitro

Analyses of the cell structures in the islets of Langerhans revealed the presence of 2 predominant cations, calcium (beta-granules and saccules, mitochondria, sac membranes, and cell membranes) and zinc (secretory granules, encasing membraneous sacs) in association with organelles which involve directional secretion. Both elements are known to interact with microtubules influencing their structural and functional properties, e.g. movement of secretory granules. Influences of Zn2+ on microtubules are investigated with a view to interactions in vitro with and without diabetogenic substances. Turbidimetry and electron microscopic investigations showed that under the conditions mentioned above, alloxan of a concentration of 2 x 10(-5) mol/l (alloxan/tubulin 1:1) inhibits the formation of microtubules and increases the portion of microtubules stabilized of 4 degrees C. The Zn2(+)-induced formation of MTP sheets is not influenced by alloxan and the metal complex forming agent EGTA, if the molar concentrations of the substance and Zn2+ are equally high. With a molar proportion of 2:1 (EGTA:Zn2+), the formation of sheets does not longer occur and only microtubules are formed, whereas neither sheets nor microtubules were assembled by alloxan with this molar proportion. However, neither the assembly of microtubules nor the formation of Zn2(+)-induced sheets are influenced by alloxanic acid in both molar proportions. It is shown that the diabetogenic alloxan influences the formation of microtubules and that performed microtubules are destroyed. This result of alloxan corresponds to its antimitotic activity analogously to the wellknown effect of colchicine (s. Schmidt et al. 1990).(ABSTRACT TRUNCATED AT 250 WORDS)     

The role of cyclic adenosine 3',5'-monophosphate (cAMP) in the mechanism of action of tricyclic antiderpressants.

In the course of investigations on experimental arterial hypertension in rats, it has been stated, that imipramine prevents the development of hypertension and that is simultaneously causes an accumulation of cAMP in the vessel walls. The relationship between the two phenomena has been discussed.     

Functional metal-porphyrazine derivatives and their polymers, 4. Synthesis of poly(styrene) bonded Fe(III)- as well as Co(II)-4,4′,4″,4″′-tetracarboxyphthalocyanine and their catalase-like activity

Metal-4,4′,4″,4″′-tetracarboxyphthalocyanine [Metal = Fe(III), Co(II), Mt-taPc] were synthesized by the hydrolysis of metal-4,4′,4″,4″′-tetracarboxamidephthalocyanine (Mt-tamPc). These metal-taPc are soluble in water and in aprotic polar solvents such as N,N′-dimethylformamide. Poly(styrene) bonded Mt-taPc was synthesized by Friedel-Crafts reaction of poly(styrene) with Mt-taPc tetraacid chloride. The polymers contain about 4 mole-% Mt-Pc rings which are covalently bonded to poly(styrene). The decomposition reaction of hydrogen peroxide by catalysis with polystyrene containing Mt-Pc rings was carried out in heterogeneous aqueous media at pH 7,0. The polymer catalysts show a catalase-like activity. The activation energies with the polymer bonded Mt-Pc were found to be about half of those with Mt-taPc. From continuous flow experiments in a column, the polymer attached catalyst was found to be very stable, compared with free Mt-taPc.     

The action of polyether ionophorous antibiotics (monensin,salinomycin, lasalocid) on developmental stages ofEimeria tenella (Coccidia,Sporozoa) in vivo and in vitro: Study by light and electron microscopy

The effect of three polyether antibiotics (monensin, salinomycin, lasalocid) on developmental stages ofEimeria tenella (Coccidia, Sporozoa) was studied in vivo and in vitro by means of light and electron microscopy. It was found that these three drugs act against free merozoites, which are destroyed by bursting of the cell border (i.e. pellicle), endoplasmic reticulum and internal organelles even after very short exposure times (20 min) in media containing 1 ppm, 10 ppm or 100 ppm of these drugs. Sporozoites, however, survived these drug concentrations during an exposure time of 30 min (this would be sufficient to penetrate host cells and start development). Intracellular stages, which were situated in a parasitophorous vacuole within an intact host cell, were not attacked, apparently because these drugs are almost incapable of penetrating host cells. On the other hand, parasites (such as differentiated schizonts, gamonts) located within degenerating host cells showed slight disintegration, which did not necessarily led to their death. From these results it becomes clear why these polyether antibiotics have to be fed daily. Doses of 70 ppm salinomycin, 125 ppm monensin and 125 ppm lasalocid were found to bring about an equivalent protective effect against an infection with 40,000Eimeria tenella oocysts.     

The protective action of fluocortin butylester (FCB) in the nasal antigen provocation test: a controlled double-blind, crossover study

Fluocortin butylester (FCB), a locally active corticosteroid, was inhaled as a fine powder mixed with lactose using the rhinolator in a comparative double-blind, crossover study against placebo. Fifty patients of both sexes and aged from 16 to 46 years with an established seasonal allergic rhinitis, but free of symptoms, took part in this trial. The determination of the protective action after allergen provocation was performed after seven days treatment with 4 mg FCB or placebo. Measurements of the nasal resistance and the temperature were taken after provocation. The symptoms of nose and eyes were recorded. The protective effect of FCB against nasal provocation with grass pollen extracts was statistically proved.     

The mechanism of action of a synthetic immunomodulator, 3,6-bis(2-piperidinoethoxy)acridine trihydrochloride (CL 246,738), in natural killer cell activation in animals.

CL 246,738 is a low molecular weight, synthetic immunomodulator. The present study was done to determine the interaction among interferon (IFN), macrophages, and natural killer (NK) cells in mice following oral administration of CL 246,738. Splenic NK activity as evidenced by lysis of YAC-1 lymphoma cells in vitro was found to be augmented by the compound not only in normal mice, but also in immunodeficient beige and nude mice. Lytic activity remained elevated from one to seven days after a single treatment and the peak activation varied depending on the source of NK cells. NK cell activity associated with the peritoneal exudate cell population peaked at day 1 and returned to normal by day 2, whereas NK cell activity of peripheral blood lymphocytes peaked at day 3 and remained significantly elevated until day 7. Liver associated NK activity peaked at day 4 and remained significantly elevated at day 7 after treatment with CL 246,738. Lung associated NK activity was elevated by day 1 after treatment, peaked at day 4 and returned to normal by day 7 after drug administration. The drug was also effective in inducing IFN in all mouse strains tested. When these drug-treated mice were given antibody to IFN-(alpha + beta) but not to IFN-(beta), both IFN levels and NK cell activity decreased, suggesting the importance of IFN-(alpha) in this system. Furthermore, mice that had received carrageenan prior to, but not after CL 246,738 administration showed reduced serum IFN titers as well as decreased NK cell activity, indicating that macrophages played an intermediate role in immune enhancement by the drug.(ABSTRACT TRUNCATED AT 250 WORDS)