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PubMed2000

Mobility of antimony in soil and its availability to plants.

In a historical mining area residual material has been filled on land and these locations are used today as agricultural soils or house gardens. The antimony concentrations in these soils are up to 500 mg/kg. Antimony transfer into 19 vegetable and crop species was investigated. In grain and other storage organs up to 0.09 mg Sb/kg were found, whereas maximum antimony concentrations in shoots and leaves were determined to be 0.34 mg Sb/kg and 2.2 mg Sb/kg, respectively. Despite the high antimony contamination of the soils, concentrations in the investigated plants in general corresponded to concentrations only reported for uncontaminated soils. NH4NO3 extraction of some of the soils indicated that the mobile fraction of antimony present was only 0.06-0.59%. In contrast, in leaves of spinach grown under controlled conditions in soils with a high mobile antimony content an accumulation of the element could be observed: a maximum value of 399 mg Sb/kg was detected, and a correlation between the mobile fraction in the soils and antimony in leaves was found.

Antimony↗
PubMed1999

Antimony in municipal waste.

Antimony content in municipal waste was studied. Sampled municipal waste was dried, crushed and analyzed. Antimony determinations were performed by Kjeldahl decomposition--batch hydride generation spectrometry and neutron activation analysis. Overall content of antimony in waste was 40-50 g/t raw waste. It was estimated than 20% of the annual production of antimony was discarded as municipal waste in Japan. Leaching of antimony from antimony-added materials may occur, because "small tips" involved considerable amounts of antimony.

Antimony↗
PubMed1998

Suppression of arsenic-induced chromosome mutagenicity by antimony.

Arsenic and antimony are two semimetals sharing some chemical as well as toxicological properties. Both elements are clastogenic but not point mutagenic in their trivalent state of valency. Environmental exposure to arsenic was proven to be associated with increased rates of various types of cancers. Antimony is suspected to be carcinogenic to humans. Arsenic and antimony can be found as environmental co-contaminants resulting in co-exposure to man. However, in most regions where arsenic was found in elevated environmental amounts, it was not investigated whether an additional exposure to antimony was predominating. In this study, the chromosome mutagenicity induced by arsenic(III) was significantly suppressed by antimony(III) in the micronucleus test with V79 cells. The results demonstrate the necessity to identify putative environmental co-contaminations of antimony in the regions contaminated with arsenic and to determine the impact of antimony co-exposure on arsenic genotoxicity and carcinogenicity in man in vivo.

Animals↗
PubMed2004

Antimony concentrations in nodal tissue can confirm sentinel node identity.

The sentinel node biopsy procedure is a highly accurate method of staging patients with cutaneous melanoma and the tumor-harboring status of sentinel nodes is the most important prognostic factor. For the procedure to provide accurate prognostic information, however, it is essential that 'true' sentinel nodes are removed and examined thoroughly. A technique to confirm sentinel node identity may reduce the false-negative rate of the procedure. We have found that antimony (originating from the antimony sulfide colloid used for preoperative lymphoscintigraphy in our institution) can be measured in tissue sections of sentinel nodes using inductively coupled plasma mass spectrometry. The aims of this study were to determine whether antimony concentrations can be used to confirm that removed sentinel nodes are 'true' sentinel nodes and to differentiate sentinel nodes from nonsentinel nodes. In all, 24 patients who had both a tumor-positive sentinel node and a tumor-negative nonsentinel node removed from one regional node field during the same operation, were identified. Tissue sections (50 microm) thick were cut from archival paraffin blocks of each of the sentinel nodes and nonsentinel nodes. Antimony concentrations in the tissue sections were measured using inductively coupled plasma mass spectrometry. The median and mean concentrations of antimony in parts per billion were 0.526 and 1.198, respectively (range 0.020-7.596) in the sentinel nodes, and 0.043 and 0.123 (range 0-0.800) in the nonsentinel nodes (P = 0.004). In four of the 24 pairs, both the presumed sentinel nodes and the nonsentinel nodes had very low antimony levels (less than 0.18 parts per billion), suggesting that nodes designated as sentinel nodes may not have been 'true' sentinel nodes. It is concluded that determination of antimony concentrations within sentinel nodes using the highly sensitive method of inductively coupled plasma mass spectrometry can confirm the identity of sentinel nodes and validate the sentinel node technique.

Antimony↗
PubMed2000

Methodologies for determination of antimony in terrestrial environmental samples.

Methodologies for the environmental analysis of total antimony and aqueous chemical speciation are critically reviewed, including preparation techniques for aqueous and solid matrices and the determination of solid state partitioning and recommendations are given for future research directions. Concentrations of total antimony commonly present in aqueous and solid environmental samples are readily determined using present day analytical techniques. This has resulted primarily from technological advances in microwave digestion for solid matrices and the development of plasma based analyte detection systems. ICP-AES and ICP-MS techniques are both utilised for the environmental analysis of total antimony concentrations. However, ICP-MS is increasingly favoured as a result of reduced spectral interferences and the potential for analyte detection in the pg mL(-1) range. Determination of aqueous antimony speciation presents a number of complex analytical challenges and highly selective separation and identification techniques are required prior to detection. The majority of published techniques including common applications of hydride generation are insufficiently selective for the determination of intrinsic chemical speciation and often only oxidation state data are obtained. The recent in-line applications of HPLC-ICP-MS offer the potential for highly selective separations of aqueous antimony species and determination of detailed chemical speciation data. However, considerable development work is required to optimise chromatographic separations and identify uncharacterised species resident in environmental systems. Analytical techniques to aid the determination of antimony's associations with solid environmental matrices include the application of chemical extraction procedures and leaching experiments. To date, this area of analytical research has received little attention and further studies are required to elucidate this aspect of antimony's environmental chemistry.

Animals↗
PubMed2005

Investigation into antimony mobility in sewage sludge fermentation.

Antimony is distributed in the environment in inorganic and organic species with different solubility and mobility characters. Here we investigate the transformation of antimony in view of biomethylation during sewage sludge fermentation as a case study for an anaerobic environment. Our approach was to identify if antimony methylation follows the Challenger pathway by using isotopically enriched antimonite (123Sb(v)). The antimony source was subjected to methylation in sewage sludge, an anaerobic dominant methanogenic Archaea community. The antimony species were determined in the gas phase using cryotrapping (CT)-GC-ICP-MS, and in the medium (sewage slude) by hydride generation (HG) prior CT-GC-ICP-MS. The determined 123/121Sb isotope ratios in the volatile trimethylstibine and non-volatile methylantimony species indicated that the methylation follows the proposed methylation pathway. With this approach we were able to quantify 123Sb incorporation into monomethyl-, dimethyl- and trimethylantimony, respectively. The incorporation decreased with further methylation from 91% to 82% and 73%. Volatilisation as trimethystibine was generally lower than 0.1%, however, up to 0.8% of added antimony was found methylated to methylantimony species and mainly accumulated in the cell. Moreover, antimony biomethylation was enhanced by stimulation of the anaerobic communities of methanogenic Archaea and sulfate reducing bacteria (SRB), with the methanogens showing a higher activity.

Antimony↗
PubMedDate not supplied

Evaluation of a miniature antimony electrode for measurement of myocardial pH.

Myocardial pH reflects the metabolic status of the heart and pH monitoring is an invaluable way to monitor the efficacy of myocardial protection during cardiac surgery. We developed a miniature antimony electrode for pH measurement in the heart. We examined the sensitivity, accuracy and the effects of temperature and oxygen tension on pH readings with this electrode in standard buffers and in anaesthetized dogs. In buffers the antimony electrode exhibited a gradient of -50.3 +/- 1.8 mV pH-1 at 25 degrees C, close to the Nernstian slope and showed a high correlation with conventional glass electrode readings (mean difference 0.027 +/- 0.0035 pH, r2 = 0.97). With increasing temperature the antimony electrode pH readings increased by 0.03 +/- 0.002 pH degree C(-1). With increasing PO2 the pH reading decreased (-0.73 pH/log PO2 mm Hg, r2 = 0.96). In the dog heart the antimony electrode showed a decrease in myocardial pH with increasing PCO2, and an increase in pH when NaHCO3 was given intravenously. Coronary occlusion resulted in paradoxically higher pH readings with the antimony electrode due to the effect of lowered myocardial PO2 interfering with pH measurement. The dissolution of antimony from the electrode in blood plasma was tested and found to be low. These studies suggest that antimony electrodes have low toxicity and provide accurate pH determinations under conditions of constant PO2. For more widespread clinical application, the problem of oxygen interference needs to be solved.

Animals↗
PubMed1981

Inducible plasmid-determined resistance to arsenate, arsenite, and antimony (III) in escherichia coli and Staphylococcus aureus.

Plasmids in both Escherichia coli and Staphylococcus aureus contain an "operon" that confers resistance to arsenate, arsenite, and antimony(III) salts. The systems were always inducible. All three salts, arsenate, arsenite, and antimony(III), were inducers. Mutants and a cloned deoxyribonucleic acid fragment from plasmid pI258 in S. aureus have lost arsenate resistance but retained resistances to arsenite and antimony, demonstrating that separate genes are involved. Arsenate-resistant arsenite-sensitive S. aureus plasmid mutants were also isolated. In E. coli, plasmid-determined arsenate resistance and reduced uptake were additive to that found with chromosomal arsenate resistance mutants. Arsenate resistance was due to reduced uptake of arsenate by the induced plasmid-containing cells. Under conditions of high arsenate, when some uptake could be demonstrated with the induced resistant cells, the arsenate was rapidly lost by the cells in the absence of extracellular phosphate. Sensitive cells retained arsenate under these conditions. When phosphate was added, phosphate-arsenate exchange occurred. High phosphate in the growth medium protected cells from arsenate, but not from arsenite or antimony(III) toxicity. We do not know the mechanisms of arsenite or antimony resistance. However, arsenite was not oxidized to less toxic arsenate. Since cell-free medium "conditioned" by prior growth to induced resistant cells with toxic levels of arsenite or antimony(III) retained the ability to inhibit the growth of sensitive cells, the mechanism of arsenite and antimony resistance does not involve conversion of AsO2- or SbO+ to less toxic forms or binding by soluble thiols excreted by resistant cells.

Antimony↗
PubMed1990

Simultaneous comparison of 24-hour intragastric pH recording using glass and antimony electrodes in man.

Based upon the results of in vitro studies, antimony electrodes are generally considered to have inferior electrochemical properties when compared with glass electrodes. Since a direct comparison in man is lacking, a 24-hour ambulatory intragastric pH recording was performed in 10 healthy male subjects simultaneously using glass and antimony electrodes. In the first set of experiments (when both electrodes were calibrated in buffers of pH 7 and 1 at 37 degrees C: beaker calibration) significantly lower pH recordings during fasting periods were registered with the antimony electrode. This difference could be corrected by a modified calibration, using the external skin reference electrode of the antimony electrode (finger calibration). In the second series of experiments (performed after finger calibration) comparable recordings of 24-hour intragastric pH could be obtained with antimony and glass electrodes in the same subjects. The reason for statistically insignificant differences of pH recordings with both electrodes in the early hours of the morning remains uncertain. The drift of glass and antimony electrodes did not differ. It is concluded from these data that, after adequate calibration, inferior electrochemical properties of antimony electrodes do not influence intragastric pH recordings in man.

Adult↗
PubMed1995

Cross-resistance between cisplatin, antimony potassium tartrate, and arsenite in human tumor cells.

Cross-resistance between cisplatin (DDP) and metalloid salts in human cells was sought on the basis that mechanisms that mediate metalloid salt cross-resistance in prokaryotes are evolutionarily conserved. Two ovarian and two head and neck carcinoma cell lines selected for DDP resistance were found to be cross-resistant to antimony potassium tartrate, which contains trivalent antimony. The DDP-resistant variant 2008/A was also cross-resistant to arsenite but not to stibogluconate, which contains pentavalent antimony. A variant selected for resistance to antimony potassium tartrate was cross-resistant to DDP and arsenite. Resistance to antimony potassium tartrate and arsenite was of a similar magnitude (3-7-fold), whereas the level of resistance to DDP was greater (17-fold), irrespective of whether the cells were selected by exposure to DDP or to antimony potassium tartrate. In the resistant sublines, uptake of [3H]-dichloro(ethylenediamine) platinum(II) was reduced to 41-52% of control, and a similar deficit was observed in the accumulation of arsenite. We conclude that DDP, antimony potassium tartrate, and arsenite all share a common mechanism of resistance in human cells and that this is due in part to an accumulation defect.

Anions↗
PubMed1998

Human biomonitoring of arsenic and antimony in case of an elevated geogenic exposure.

Part of the northern Palatinate region in Germany is characterized by elevated levels of arsenic and antimony in the soil due to the presence of ore sources and former mining activities. In a biomonitoring study, 218 residents were investigated for a putative increased intake of these elements. Seventy-six nonexposed subjects in a rural region in south lower Saxony were chosen as the reference group. Urine and scalp hair samples were obtained as surrogates to determine the internal exposures to arsenic and antimony. The analyses were performed using graphite furnace atomic absorption spectrometry except for arsenic in urine, which was determined by the hydride technique. This method does not detect organoarsenicals from seafood, which are not toxicologically relevant. In the northern Palatinate subjects, slightly elevated arsenic contents in urine and scalp hair (presumably not hazardous) could be correlated with an increased arsenic content in the soil. On the other hand, the results did not show a correlation between the antimony contents in the soil of the housing area and those in urine and hair. Except for antimony in scalp hair, age tended to be associated with internal exposures to arsenic and antimony in both study groups. Consumption of seafood had a slight impact on the level of urinary arsenic, which is indicative of the presence of low quantities of inorganic arsenicals and dimethylarsinic acid in seafood. The arsenic and antimony contents in scalp hair were positively correlated with the 24-hr arsenic excretion in urine. However, antimony in scalp hair was not correlated with seafood consumption as was arsenic in scalp hair and in urine. This indicated the existence of unidentified common pathways of exposure contributing to the alimentary body burden. Short time peaks in the 24-hr excretion of arsenic in urine, which could not be assigned to a high consumption of seafood, were detected for six study participants. This suggests that additional factors relevant in the exposure to arsenic are still unidentified.

Adolescent↗
PubMed2000

Novel methods for the encapsulation of meglumine antimoniate into liposomes.

The antimonial drug, meglumine antimoniate, was successfully encapsulated in dehydration-rehydration vesicles and in freeze-dried empty liposomes (FDELs). High encapsulation efficiencies (from 28 to 58%) and low weight ratios of lipids to encapsulated antimony (from 1:0.15 to 1:0.3) were achieved. These formulations, contrary to those obtained by conventional methods, can be stored as intermediate lyophilized forms and reconstituted just before use. The efficacy of FDEL-encapsulated meglumine antimoniate was evaluated in hamsters experimentally infected with Leishmania chagasi. A significant reduction of liver parasite burdens was observed in animals treated with this preparation, when compared to control animals treated with empty liposomes. In contrast, free meglumine antimoniate was found to be inefficient when administered at a comparable dose of antimony. This novel liposome-based meglumine antimoniate formulation appears to be promising as a pharmaceutical product for the treatment of visceral leishmaniasis.

Analysis of Variance↗
PubMed1992

Alkaline oesophageal reflux--an artefact due to oxygen corrosion of antimony pH electrodes.

Antimony electrodes are widely used for gastro-oesophageal pH monitoring. They are also sensitive to oxygen, however, especially at low PO2 levels, which are known to shift recorded values in the alkaline direction. This study, which compares antimony and glass electrodes for oesophageal pH monitoring in six adults, shows that values recorded by antimony electrodes are 2.1 +/- 0.8 pH units (mean +/- SD) higher than by glass electrodes (p < 0.001; n = 7642). A further 52 patients with suspected gastro-oesophageal reflux were investigated by 24-h pH monitoring by means of antimony electrodes. In these patients the oesophageal pH was higher than 8.0 for 7% of the time (range, 0-60%). The alkaline periods recorded with antimony electrodes were all protracted in time, smoothly increasing from a neutral pH, and did not correspond to a sudden increase in pH, which would be expected if alkaline reflux had occurred. It is concluded that high pH values obtained by antimony electrodes are due to the oxygen sensitivity of the electrodes. The diagnosis of alkaline reflux seems to be valid only when pH monitoring is performed with glass electrodes or when values obtained with antimony electrodes are adjusted for the influence of the oxygen tension in the oesophagus.

Adult↗
PubMed1982

Antimony in lung, liver and kidney tissue from deceased smelter workers.

Tissue concentrations of antimony in lung, liver, and kidney tissue from a group of deceased smelter workers from northern Sweden have been compared with those of a group of persons without occupational exposure from a nearby area. Neutron activation analysis was used to determine the antimony concentration of lung tissue from exposed workers; these concentrations were 12-fold higher than those of referents (p less than 0.001). For lung tissue there was no tendency towards decreased antimony concentrations with time (up to 20 a) after the cessation of exposure, and this result indicates a long biological half-time. The highest values were found for workers who had worked for many years at the roasters and in the arsenic and selenium departments. There was no significant difference between the antimony concentration of the lung tissue from workers who had died of lung cancer and those of persons who died of other malignancies, cardiovascular disease, or other causes. This finding does not however rule out the possibility of a role for antimony in the etiology of lung cancer among smelter workers since multiple factors may have been operating. The antimony concentration of the liver tissue and the kidney cortex did not differ from the corresponding values of the reference group; this finding indicates either a short biological half-time or insignificance for the systemic distribution of antimony.

Adult↗
PubMed1983

Continuous pH monitoring with monocrystalline antimony electrodes: toxicity considerations from studies on heparinized human plasma.

Monocrystalline antimony electrodes can be used as pH sensors for continuous monitoring in vivo. The electric potential of the electrodes stems from a corrosion reaction in which antimony metal dissolution constitutes the anodic reaction. In this study the amount of antimony which leaves a monocrystalline antimony sensor, when monitoring pH in thermostatically controlled sterile human heparinized plasma, was determined by neutron activation analyses. From these results the toxicity hazard of using such electrodes in vivo is assessed. It is concluded that the amount of antimony released from a monocrystalline pH sensor, when used in a biological medium, is small compared with the amount of antimony accepted for administration as a medical therapeutic. Thus it should be safe from the toxicological point of view to use monocrystalline antimony electrodes for in vivo pH monitoring.

Antimony↗
PubMed1999

Stage-specific activity of pentavalent antimony against Leishmania donovani axenic amastigotes.

The standard treatment of human visceral leishmaniasis involves the use of pentavalent antimony (SbV) compounds. In recent years increasing numbers of clinical failures of treatment with SbV have been reported, probably due to the development of parasite resistance to this compound. The mode of action and mechanisms of resistance to SbV have not been fully elucidated. In the present study an axenic amastigote culture was used to study the in vitro responses of Leishmania donovani to SbV. Susceptibility to both sodium stibogluconate and meglumine antimoniate was found to be stage specific. Amastigotes were 73 to 271 times more susceptible to SbV than were promastigotes. As opposed to SbV, trivalent antimony (SbIII) was similarly toxic to both developmental stages. When promastigotes were transformed to amastigotes, susceptibility to meglumine antimoniate developed after 4 to 5 days, upon the completion of differentiation. In contrast, with transformation from amastigotes to promastigotes, resistance to meglumine antimoniate was acquired rapidly, within 24 h, before the completion of differentiation. The culture of promastigotes at an acidic pH (5.5) or at an elevated temperature (37 degrees C) alone did not lead to the appearance of SbV susceptibility, emphasizing the requirement of both these environmental factors for the development of SbV susceptibility. A previously isolated sodium stibogluconate (Pentostam)-resistant L. donovani mutant (Ld1S.20) is also resistant to meglumine antimoniate, indicating cross-resistance to SbV-containing compounds. In contrast, no cross-resistance was found with SbIII, suggesting a mechanism of SbV resistance different from that described in Leishmania tarentolae. These data show that L. donovani susceptibility to SbV is parasite intrinsic, stage specific, and macrophage independent.

Animals↗
PubMed1995

Antimony oxidation states in antileishmanial drugs.

Chemical methods specific for the determination of the levels of trivalent antimony (Sb+3) and pentavalent antimony (Sb+5) were used to investigate proprietary formulas used to treat leishmaniasis. Trivalent antimony was determined by differential pulse polarography, whereas Sb+5 was determined by iodine titration. Proprietary formulas based on N-meglumine antimoniate (Glucantime) were analyzed in detail. The results showed Sb+3 in all ampules of Glucantime. In formulations said to contain either 85 or 100 mg of Sb+5/ml, we found both forms of antimony. The amount of Sb+3 ranged from 10.5 to 15.8% (10.06-18.96 mg of Sb/ml). These findings raise issues on product stability and standardization and may help to clarify resistance to antimonial drugs and the reducing effect of tissue on Sb+5.

Antimony↗
PubMed2004

Determination of the antimony valence state in Eu10Mn6Sb13.

The antimony-121 Mössbauer spectra of Eu10Mn6Sb13 have been measured between 2 and 295 K. Although the Zintl formalism indicates that the nine crystallographically distinct antimony sites in Eu10Mn6Sb13 should have formal valence states of -2, -1, 0, and +1, the Mössbauer spectral isomer shifts reveal that the valence states of the different sites are all quite similar and correspond to an average electronic configuration for antimony of 5s(1.7)5p(4.0). This configuration corresponds to an excess of negative charge on the antimony of 0.7 or an average valence of -0.7, a valence which is rather consistent with the average antimony valence of -0.61 obtained from the Zintl formalism for the nine antimony sites in Eu10Mn6Sb13. The spectra obtained between 90 and 295 K are more consistent with the absence rather than the presence of any transferred magnetic hyperfine field at the antimony. In contrast, the spectra obtained at 2 and 5 K reveal the presence of an average transferred magnetic hyperfine field of ca. 8 T, a field that arises from the ferromagnetic ordering of the near-neighbor manganese(II) ions.

Journal Article↗