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PubMed1993

In vitro cyanide release of four prussian blue salts used for the treatment of cesium contaminated persons.

Prussian blue salts are used in clinical practice as an antidote for the treatment of humans contaminated with radioactive cesium. A decomposition product of these Prussian blue salts may be the highly toxic cyanide. A method to simulate gastrointestinal cyanide-release was applied to four different Prussian blue salts: K3Fe[Fe(CN)6], Fe4[Fe(CN)6]3, NH4Fe[Fe(CN)6] (pur. and unpur.). Cyanide-release was higher in artificial gastric juice than in water and artificial intestinal juice. Under all conditions cyanide-release from Fe4[Fe(CN)6]3 was the lowest. Since Fe4[Fe(CN)6]3 also binds more cesium, it appears to be the most suitable Prussian blue salt for use as an antidote after radiocesium contamination in humans.

Antidotes↗
PubMedDate not supplied

Cesium ions influence cultured cell behavior by modifying specific subcellular components: the role of membranes and of the cytoskeleton.

The exposure of the epidermoid cell line A431 to different concentrations of CsCl was assessed using different methodological approaches. Two different effects were detected depending upon the concentration of the agent: at low concentrations, cell modification was represented mainly by a very pronounced cell flattening and an alteration of the cell-to-cell contacts, interpreted as an increase in cell adhesion. At higher concentrations, a clear pathogenic effect was observed that allowed the formulation of the hypothesis that specific mechanisms of toxicity at the subcellular level involving mitochondrial and cytoskeletal function can exist. In addition, membrane order parameters, as detected by electron paramagnetic resonance (EPR) spectroscopy, displayed a dose-dependent increase in membrane rigidity. Results reported here seem to suggest that cesium ions can enter the cell, modify plasma membrane integrity and alter some specific cytoplasmic components, e.g. the cytoskeleton. Considering that environmental contamination by cesium as a result of radioactive fallout is of major importance and that few data are available thus far on this matter, this study provides evidence for the possible mechanisms of action of the non-radioactive form of this ion in cells.

Cell Adhesion↗
PubMed1994

Attenuation effects on the kerma rates in air after cesium depositions on grasslands.

Since the reactor accident of Chernobyl, cesium depth profiles and nuclide-specific kerma rates in air have been determined for various grassland sites in south Bavaria and in Ukraine. The sites are described by soil characteristics, annual precipitation, distance from release point, mode of deposition, and activity per unit area. The effects of surface roughness and migration of cesium into the soil on the kerma rate in air over grasslands was determined by two methods. The kerma rates in air obtained by the evaluations of in situ gamma-ray spectrometry results and of measured activity distributions in the soil showed only negligible differences for the observation period of 6 years after deposition. For the sites in Ukraine the kerma rate in air per activity per unit area was found to be systematically 40% higher than in Bavaria. The results from Bavaria on the attenuation of the kerma rate and a data set, including experiences from the weapons test fallout, are analytically approximated as a function of time up to 25 years after deposition.

Air Pollutants, Radioactive↗
PubMedDate not supplied

On the mechanism of cesium-induced voltage and current tails in single ventricular myocytes.

The mechanisms by which different concentrations of cesium modify membrane potentials and currents were investigated in guinea pig single ventricular myocytes. In a dose-dependent manner, cesium reversibly decreases the resting potential and action potential amplitude and duration, and induces a diastolic decaying voltage tail (Vex), which increases at more negative and reverses at less negative potentials. In voltage-clamped myocytes, Cs+ increases the holding current, increases the outward current at plateau levels while decreasing it at potentials closer to resting potential, induces an inward tail current (Iex) on return to resting potential and causes a negative shift of the threshold for the inward current. During depolarizing ramps, Cs+ decreases the outward current negative to inward rectification range, whereas it increases the current past that range. During repolarizing ramps, Cs+ shifts the threshold for removal of inward rectification negative slope to less negative values. Cs+-induced voltage and current tails are increased by repetitive activity, caffeine (5 mM) and high [Ca2+]O (8.1 mM), and are reduced by low Ca2+ (0.45 mM), Cd2+ (0.2 mM) and Ni2+ (2 mM). Ni2+ also abolishes the tail current that follows steps more positive than ECa. We conclude that Cs+ (1) decreases the resting potential by decreasing the outward current at more negative potentials, (2) shortens the action potential by increasing the outward current at potentials positive to the negative slope of inward rectification, and (3) induces diastolic tails through a Ca2+-dependent mechanism, which apparently is an enhanced electrogenic Na-Ca exchange.

Action Potentials↗
PubMed1980

Proteoglycan complex and proteoglycan subunit polydispersity. Study by isopycnic centrifugation in cesium sulfate density gradients.

A true isopycnic centrifugation method for the study of the bovine nasal cartilage proteoglycan polydispersity is presented. The use of cesium sulfate as gradient forming salt instead of cesium chloride allowed proteoglycan banding without any sedimentation at the bottom of the centrifuge tube. Apparent buoyant densities of proteoglycan monomer and proteoglycan aggregate were different. The present method provides a useful tool for the study of proteoglycan polydispersity and also allows us to follow the distribution of the link proteins in different proteoglycan extracts.

Amino Acids↗
PubMed1984

Nutrients and cancer: an introduction to cesium therapy.

A brief overview on the relevance in dietary factors in both development and prevention of cancer is presented. The pharmacologic properties of various food ingredients are discussed. Establishing of a special diet for the cancer patient is suggested. In addition, avoidance of certain foods is recommended to counteract mucus production of cancer cells. Evaluation of the nutrient content of certain diets in regions with low incidence of cancer has advanced the use of certain alkali metals, i.e., rubidium and cesium, as chemotherapeutic agents. The rationale for this approach termed the "high pH" therapy resides in changing the acidic pH range of the cancer cell by cesium towards weak alkalinity in which the survival of the cancer cell is endangered, and the formation of acidic and toxic materials, normally formed in cancer cells, is neutralized and eliminated.

Cesium↗
PubMed1984

Pharmacological and toxicological investigations of cesium.

Cesium, a mineral resource abundantly present in Manitoba with important existing and potential industrial applications was investigated to study its effects on biological systems. Several rodent models of pharmacological activities were utilized. The profile that emerged indicated that cesium is only moderately toxic and exerts salubrious effects which could be gainfully investigated for application in the treatment of certain psychological disorders and some tumors. Its conjunction with existing pharmacological agents for these two types of disorders could yield a pharmacologically active yet less toxic therapeutic combination.

Animals↗
PubMed1990

Clastogenic effects of cesium chloride on mouse bone marrow cells in vivo.

Clastogenic effects of cesium chloride (CsCl) on mouse bone marrow cells in vivo following oral administration were studied after 24 h. The incidence of chromosome aberrations increased linearly with increasing concentrations of the chemical from 1/20th to 1/5th of the LD50. The frequency of cell division was also enhanced by the lower doses but higher doses were mitostatic. This report is the first on the clastogenicity of cesium on animals.

Administration, Oral↗
PubMed1985

The estimation of virus density in isopycnic cesium chloride gradients.

Methods for estimating the density of virus particles after isopycnic centrifugation in cesium chloride gradients were examined. If solutions were prepared in different buffers, the standard tables relating refractive index and density, based on solutions prepared in water, did not give consistent estimates even if corrections were made for the greater refractive indices of the buffers. Depending on the method and buffer used, estimates of the density of cricket paralysis virus, an insect picornavirus, differed by as much as 0.05 g/ml. However, consistent estimates were obtained if separate regression equations were derived to relate refractive index and density for each different buffer solution of cesium chloride. This has wider implications and could account for density differences or variations in estimates reported for many other viruses.

Centrifugation, Isopycnic↗
PubMed1990

Prostaglandin modulation of early afterdepolarizations and ventricular tachyarrhythmias induced by cesium chloride combined with efferent cardiac sympathetic stimulation in dogs.

Prostaglandins inhibit efferent cardiac sympathetic nerve effects by acting at presynaptic sites and may act to suppress some arrhythmias. In the present study, the effects of intravenous administration of prostacyclin (PGI2) and prostaglandin E2 (PGE2) on early afterdepolarizations and ventricular tachycardia induced by cesium chloride (0.5 mmol/liter per kg body weight intravenously) combined with stimulation of bilateral ansae subclaviae in anesthetized dogs were examined. The right atrium was paced at a constant cycle length of 600 ms. A left ventricular endocardial monophasic action potential catheter was used to detect early afterdepolarizations. Prostacyclin (0.2 microgram/kg per min) reduced the amplitude of the early afterdepolarizations (39.2 +/- 8.4% of the monophasic action potential amplitude during control study to 28.7 +/- 5.5%, n = 10; p less than 0.001) as well as the prevalence of ventricular tachycardia (11 of 14 dogs during control study to 5 of 14 dogs; p = 0.031). Prostaglandin E2 (0.2 to 0.6 microgram/kg per min) did not significantly reduce the early afterdepolarization amplitude (34.7 +/- 8.9% to 25.1 +/- 10.7%, n = 8; p = 0.085) or the prevalence of ventricular tachycardia (8 of 10 versus 6 of 10 dogs; p = 0.50). Alpha- and beta-adrenoceptor blockade with combined intravenous administration of propranolol (0.5 mg/kg) and phentolamine (0.3 mg/kg) decreased the amplitude of the early afterdepolarizations induced by cesium chloride and bilateral ansae subclaviae stimulation from 38.6 +/- 11.2% to 18.8 +/- 3.3% (n = 6; p = 0.005). Additional administration of PGI2 further reduced the early afterdepolarization amplitude from 18.8 +/- 3.3% to 9.8 +/- 4.8% (n = 6; p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2006

Biosorption of cesium-137 and strontium-90 by mucilaginous seeds of Ocimum basilicum.

Mucilaginous seeds of Ocimum basilicum were used in uptake studies with cesium-137 and strontium-90. Results showed that uptake was dependent on the structural integrity of the mucilage fibrils. Water imbibed seeds showed higher adsorption of both 137Cs and 90Sr in comparison to seeds pretreated with NaOH, HCl and Na-periodate solution. The uptake was pH dependent and while some divalent metal ions had no or little detrimental effect, the alkali metal ions Li+, Na+ and K+ decreased the uptake. The maximum adsorption capacity was 160 mg cesium g(-1) and 247 mg strontium g(-1) seed dry weight.

Cesium Radioisotopes↗
PubMed1992

Purification of mucin glycoproteins by density gradient centrifugation in cesium trifluoroacetate.

A procedure for the rapid isolation of mucin glycoprotein by density gradient centrifugation in cesium trifluoroacetate (CsTFA) is described. The separation of mixtures of rat tracheobronchial mucin, DNA, hyaluronic acid, and bovine serum albumin in CsTFA gradients was superior to that in cesium bromide gradients. Inclusion of guanidinium chloride or urea in the gradient had no influence on the separation obtained. The mucins isolated from sputum samples of cystic fibrosis patients by this procedure are largely free of nucleic acid, nonglycosylated proteins, and glycosaminoglycans. The results of the use of CsTFA gradient centrifugation for the isolation of mucin from extracts of bovine submaxillary gland are also presented. The CsTFA method is particularly suitable for the high-yield isolation of mucin from individual samples which are available in limited quantities.

Animals↗
PubMed2002

Cesium cholate: determination of X-ray crystal structure indicates participation of the ring hydroxyl groups in metal binding.

The crystal structure of cesium cholate, C(24)H(36)(OH)(3) COOCs has been determined with three-dimensional X-ray diffractometer data. It crystallized in the monoclinic space group P2(1) with unit-cell dimensions a = 11.543(5) A, b = 8.614(3) A, and c = 12.662(5) A, beta(deg) = 107.95(2), V = 1197.7 A(3) and Z = 2. The atomic parameters were refined to a final r = 0.0269 and R(omega) = 0.0280 for 2342 observed reflections. Each Cs(+) is coordinated to 7 oxygen atoms from 5 different cholate anions with Cs-O distances ranging from 2.957(4) A to 3.678(5) A. In this crystal, 5 cholates are coordinated with 1 Cs(+), and 5 Cs(+) are coordinated with 1 cholate anion. Carboxyl and all the 3 ring hydroxyl groups of cholate anion participate in binding to Cs(+) simultaneously, and there is no water molecule coordinated with the Cs(+). The pattern of successive rows arranged with polar (p) and non-polar (n) faces in apposition leads to the formation of a sandwich sheet structure with polar and non-polar channels. The Cs ions lie within the polar interior of the sandwich. The H-bond network is reorganized in forming cesium cholate from cholic acid. All the oxygen atoms in cholate anion are involved in H-bonding reciprocally or with water molecules to form an extensive 3-dimensional network of H-bonds. Compared with cholic acid and other similar type of steroids, the coordination structure and H-bonding of Cs cholate crystal are distinct.

Binding Sites↗
PubMed2000

Cesium-137 source strength verification.

Over the years, the protocol for Cesium-137 source calibration has undergone a number of revisions based on updated data. The 3M Corporation issued product alerts and a revision of the calibration protocol in the early 1980s. We verified the activity of clinically used cesium tubes and found the difference with the activity stated by 3M in the range of 6-13%, which exceeds the recommended by 3M adjustment of 5% for all sources issued before 1979. Therefore, the verification and adjustment of activity should be recommended for each affected tube individually.

Cesium Radioisotopes↗
PubMedDate not supplied

Synthesis and characterization of immunogens based on calix[4]arene-crown-6 for the generation of antibodies directed towards cesium ions.

With the aim of generating antibodies directed towards cesium, a calix[4]arene-crown-6 in the 1,3-alternate conformation bearing an N-hydroxysuccinimide function was synthesized. The calixarene was coupled to bovine serum albumin using different calixarene/protein ratios, and cesium was loaded. Conjugates were characterized using trinitrobenzenesulfonic acid derivatization, matrix assisted laser desorption ionisation-mass spectrometry (MALDI-TOF-MS), and inductively coupled plasma-mass spectrometry (ICP-MS). Targeted lysines were determined after enzymatic cleavage followed by MALDI-TOF-MS, and a progressive targeting related to lysines accessibility was observed.

Animals↗
PubMed2002

Cesium adsorption on clay minerals: an EXAFS spectroscopic investigation.

Cesium adsorption on the clay minerals vermiculite and montmorillonite is described as a function of surface coverage using extended X-ray adsorption fine structure spectroscopy (EXAFS). Cesium (Cs) possessed a variable coordination environment consisting of Cs-O distances between 3.2 and 4.3 A; however, disorder typical of the Cs coordination environments prevented the resolution of all oxygen shells. On the basis of the influence of Cs loading and exchangeability on this structural arrangement, we could recognize both inner-sphere and outer-sphere adsorption complexes. The shorter Cs-O bond distance belongs to outer-sphere complexes typical of hydrated ions. In inner-sphere complexes, partially or fully dehydrated Cs coordinates directly to siloxane groups of the clay minerals forming longer Cs-O bonds. The inner-sphere adsorption complexes may have occurred within the interlayer or at frayed edge sites and were less extractable than the outer-sphere complexed Cs. Both coordination number ratios and linear combination fitting of EXAFS spectra were useful in estimating the fractions of inner-sphere and outer-sphere adsorption complexes. Our results show that X-ray absorption spectroscopy (XAS), and particularly EXAFS, is a valuable technique for exploring the type of Cs binding in environmental samples.

Adsorption↗
PubMed2005

Cesium desorption from illite as affected by exudates from rhizosphere bacteria.

Biogeochemical processes in the rhizosphere can significantly alter interactions between contaminants and soil minerals. In this study, several strains of bacteria that exude aluminum (Al)-chelating compounds were isolated from the rhizosphere of crested wheatgrass (Agropyron desertorum) collected from the Idaho National Laboratory (INL). We examined the effects of exudates from bacteria in the genera Bacillus, Ralstonia, and Enterobacter on cesium (Cs) desorption from illite. Exudates from these strains of bacteria significantly enhanced Cs desorption from illite. In addition, Cs desorption increased with increasing Bacillus exudate concentrations. Cesium desorption from illite as a function of both exudate type and concentration was positively correlated with Al dissolution, suggesting that the Al-complexing ability of the exudates played an important role in enhancing Cs desorption. The density of frayed edge sites (FES) on illite increased as a result of treatment with bacterial exudates, while the Cs/K selectivity of FES decreased. These results suggestthat exudates from bacteria isolated from the rhizosphere can enhance Cs desorption from frayed edges of illite and, therefore, can alter Cs availability in micaceous soils.

Agropyron↗
PubMed2002

Cesium effect: high chemoselectivity in direct N-alkylation of amines.

A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondary amines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondary amines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated this methodology was highly chemoselective to favor mono-N-alkylation over dialkylation. In particular, use of either sterically demanding substrates or amino acid derivatives afforded the secondary amines exclusively, offering wide applications in peptidomimetic syntheses.

Alkylation↗