Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Tin Compounds”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources
PubMed1989

Toxicity of chromium and tin to Anabaena doliolum. Interaction with sulphur-containing amino acids and thiols.

Toxicity of chromium and tin on growth, heterocyst differentiation, nitrogenase activity and 14CO2 uptake of Anabaena doliolum and its amelioration by sulphur-containing amino acids and thiols has been studied. The final growth yield was found to be approximately 51% and 58% of control at sublethal concentration of chromium and tin respectively. Among various amino acids tested, cysteine (0.05 mM) significantly restored growth, heterocyst differentiation, nitrogenase and 14CO2 uptake of test alga. Dithiothreitol (1 mM) restored all the parameters and processes better than monothiol, mercaptoethanol. It is obvious from present investigation that sulphur-containing amino acids and thiols, viz. cysteine, methionine, cystine, mercaptoethanol and dithiothreitol, may appreciably alleviate the toxicity of heavy metals in N2-fixing cyanobacteria if present in an aquatic ecosystem.

Amino Acids, Sulfur↗
PubMed2003

The function of the spleen in adults after ligation of the splenic artery of the traumatized spleen in childhood.

BACKGROUND: Ligation of the splenic artery (LSA) has been successfully used as a spleen-saving procedure in rare cases of splenic trauma in children in which management with splenorrhaphy or partial splenectomy alone was not possible. There are no data regarding the long-term effects of the procedure on the functional status of the spleen. The purpose of this study is to present and discuss our clinical and laboratory findings in adults who underwent LSA in childhood. METHODS: Our first 2 patients in whom LSA was done at ages 4 and 2 years in 1977 underwent the following examinations in the year 2000: 1, imaging of the spleen; 2, immunologic studies; and 3, peripheral blood tests. Their ages at reexamination were 27 and 25 years, respectively. RESULTS: Results were as follows: triplex ultrasound revealed normal size and echomorphology; Doppler techniques revealed normal vasculature; 99mTc-Tin colloid scanning revealed normal uptake. Immunoglobulins (IgG1 to IgG4, IgA, IgM, IgE), complement fraction (C3, C4), antibodies response to vaccinations, and peripheral blood tests all had normal results. No Howell-Jolly bodies were found. CONCLUSION: Laboratory investigations in adults with LSA during childhood disclosed undisturbed function of the spleen. LSA can be used as an adjunct to splenorrhaphy in children with rare splenic injuries involving major hilar vessels.

Adult↗
PubMed2006

Cytotoxic and genotoxic effects induced by stannous chloride associated to nuclear medicine kits.

At present, more than 75% of routine nuclear medicine diagnostic procedures use technetium-99m (99mTc). The binding between 99mTc and the drug to obtain the radiopharmaceutical needs a reducing agent, with stannous chloride (SnCl2) being one of the most used. There are controversies about the cytotoxic, genotoxic and mutagenic effects of SnCl2 in the literature. Thus, the approaches below were used to better understand the biological effects of this salt and its association in nuclear medicine kits [methylenediphosphonate (MDP) bone scintigraphy and diethylenetriaminepentaacetic acid (DTPA) kidney and brain scintigraphy]: (i) bacterial inactivation experiments; (ii) agarose gel electrophoresis of supercoiled and linear plasmid DNA and (iii) bacterial transformation assay. The Escherichia coli strains used here were AB1157 (wild type) and BW9091 (xthA mutant). Data obtained showed that both MDP and SnCl2 presented a high toxicity, but this was not observed when they were assayed together in the kit, thereby displaying a mutual protect effect. DTPA salt showed a moderate toxicity, and once more, the DTPA kit provided protection, compared to the SnCl2 effect alone. The results suggest a possible complex formation, either MDP-SnCl2 or DTPA-SnCl2, originating an atoxic compound. On the other hand, SnCl2-induced cell inactivation and the decrease in bacterial transformation generated by DTPA found in XthA mutant strain suggest that the lack of this enzyme could be responsible for the effects observed, being necessary to induce DNA damage repair.

Cell Survival↗
PubMed1990

[Teratogenic studies on stannous chloride in rats].

This paper describes teratogenic studies of stannous chloride in rats. The compound was administered to pregnant rats on gestational days 7 through 12 orally by a stomach tube at dose levels of 0 mg, 20 mg, 100 mg, 500 mg/kg of stannous chloride and fish liver oil for the positive control group. The experimental results showed that the placenta not only retains some stannous chloride but also diverts parts of the stannous chloride is the fetus. Stannous chloride showed teratogenic effects on the early growing embryos and protruding tongue of fetus.

Abnormalities, Drug-Induced↗
PubMedDate not supplied

Polylactones. 59. Biodegradable networks via ring-expansion polymerization of lactones and lactides with a spirocyclic tin initiator.

Spirocyclic tin initiators were prepared by condensation of commercial hydroxyethylated pentaerythritol with Bu(2)Sn(OMe)(2). These tin-containing spirocycles served as initiators for the ring-expansion polymerization of epsilon-caprolactone, beta-D,L-butyrolactone or D,L-lactide. The in situ polycondensation of these expanded spirocycles with terephthaloyl chloride or sebacoyl chloride yielded the desired biodegradable networks with elimination of the Bu(2)Sn group. The segment length (pore size) could be controlled via the monomer-initiator ratio (M/I) of the ring-expansion polymerization. Biodegradable networks were also obtained when Sn-containing spirocyclic polylactones were polycondensed with diphenyl dichlorosilane, benzene phosphonic dichloride, and phenyl phosphoric dichloride.

Drug Delivery Systems↗
PubMed2000

Spectrophotometric flow injection determination of total phosphorus in beer using on-line UV/thermal induced digestion.

A flow injection system for the automatic determination of total phosphorus in beer is described. The developed manifold uses a two-stage photooxidation/thermal digestion procedure together with oxidizing and hydrolyzing reagents to convert all forms of phosphorus compounds to orthophosphate. Polyphosphates are hydrolyzed by acid and heat, and organo-phosphates are digested by UV-catalyzed peroxodisulfate oxidation. The orthophosphate formed is then spectrophotometrically determined by the phosphomolybdenum blue reaction, using stannous chloride as reducing agent. The results obtained for a set of 19 beer samples (with concentrations from 120 to 735 mg P/L) were in good agreement with the reference method, the maximum relative deviation found being 4.7%. Relative standard deviations for ten consecutive determinations were lower than 1.5%, and a detection limit of 1 mg P/L was achieved.

Beer↗
PubMed1982

On the mechanism of the involvement of monoamine oxidase in catecholamine-stimulated prostaglandin biosynthesis in particulate fraction of rat brain homogenates: role of hydrogen peroxide.

The mechanism of involvement of monoamine oxidase (MAO) in catecholamine-stimulated prostaglandin (PG) biosynthesis was studied in the particulate fraction of rat brain homogenates. High concentrations of either noradrenaline (NA) or dopamine (DA) stimulated effectively PGF2 alpha formation. The same amount of 2-phenylethylamine (PEA) acted similarly, provided that it was administered together with a catecholamine analogue or metabolite possessing the 3,4-dihydroxyphenyl nucleus--3,4-dihydroxyphenylalanine (DOPA), 3,4-dihydroxyphenylacetic acid (DOPAC), 3,4-dihydroxyphenylglycol (DOPEG), 3,4-dihydroxyphenylacetaldehyde (DOPAL), or alpha-methylnoradrenaline (alpha-met-NA)--or with SnCl2. In the absence of PEA, these compounds were ineffective with regard to stimulation of PGF2 alpha formation. Catalase, pargyline, or indomethacin abolished completely PGF2 alpha formation elicited either by catecholamines or by PEA plus a 3,4-dihydroxyphenyl compound or SnCl2. With regard to the stimulation of PGF2 alpha formation in the presence of alpha-met-NA, PEA could be replaced by H2O2 generated by the glucose oxidase(GOD)-glucose system. The effect of H2O2 was inhibited by indomethacin or catalase, but pargyline was ineffective. It is assumed that catecholamines play a dual role in the activation of PG biosynthesis in brain tissue. During the enzymatic decomposition of catecholamines MAO produces H2O2, which stimulates endoperoxide synthesis. Simultaneously, catecholamines as hydrogen donors promote the nonenzymatic transformation of endoperoxides into PGF2 alpha. The possible physiological importance of these findings is discussed.

Animals↗
PubMed2004

Full automation of derivatization--solid-phase microextraction-gas chromatography-mass spectrometry with a dual-arm system for the determination of organometallic compounds in aqueous samples.

The determination of organometallic compounds in aqueous samples by in-vial derivatization and headspace solid-phase microextraction (SPME)-gas chromatography (GC)-mass spectrometry (MS) has been fully automated using a Twin PAL dual-arm robotic system. Linearity, accuracy, sensitivity for a series of n-methyl, n-ethyl, and n-phenyl metal substituted chloride compounds of tin, lead, and mercury were investigated. The automated method was compared to similar manual methods and improved precision, speed and throughput was achieved. By originally programming the Twin PAL dual-arm system with the supplier's software (Cycle Composer, Version 1.5.0) the arms on the robot were only able to work in sequence. However, in order to have a flexible system and exploit time efficiently the robotic arms must work simultaneously. This was accomplished by programming the robot with the new software package called Cruise Control 4-2 for Twin PALs. Compared to Cycle Composer, Cruise Control 4-2 enhanced the speed and throughput of the automated system further. In addition, with a built-in crash prevention protocol and an improved user interface a more user-friendly system was obtained.

Automation↗
PubMed1996

How does trimethyltin affect the brain: facts and hypotheses.

Trimethyltin, an organic compound of tin, is a potent neurotoxicant of a mechanism of action yet to be uncovered. The neuropathological findings that trimethyltin causes selective hippocampal damage with several unique features, highly reminiscent of Ammon's horn sclerosis as a final result, have raised the possibility that there is a link between trimethyltin neurotoxicity and other degenerative events for which an imbalance between neuronal inhibition/excitation has been proposed. However, there still exists a whole catalog of issues which await clarification. One of the greatest importance is how does trimethyltin reach the critical sites within the brain and what are they? Available data concerning the long-term consequences related to trimethyltin neurotoxicity are also far from being completed. This review summarizes current data from in vitro and in vivo studies on neurotoxic effects of trimethyltin. Several hypotheses on mechanisms that may lead to neuronal death induced by the toxin are presented.

Animals↗
PubMed2001

Products of metabolic activation of the antitumor drug ledakrin (nitracrine) in vitro.

The aim of this work was to characterize the products of metabolic activation of the antitumor drug ledakrin (Nitracrine) in model metabolic systems, where formation of drug-DNA adducts was previously discovered. The metabolic products obtained in different biological systems were compared with those obtained in experiments where chemical reducing agents were applied. Therefore, activation products were obtained in the presence of the microsomal fraction of rat liver and in the experiments with the reducing agents dithiothreitol, hydrazine hydrate, and SnCl(2). Furthermore, transformations of the drug with oxidoreductase enzymes DT-diaphorase and xanthine oxidase were observed. The ledakrin transformation products were separated and analyzed by HPLC with diode array detection. Structural studies of the products were performed by means of ESI-MS and NMR. Proton, carbon, and nitrogen assignments were made based upon DQF-COSY, ROESY, TOCSY, HSQC, and HMBC experiments. It was demonstrated during the reduction of ledakrin that a key metabolite, a compound with an additional five-membered ring attached to positions 1 and 9 of the acridine core and with the retained 9-aminoalkyl side chain, was formed in all the systems that were studied. It was determined that the reactive nitrogen atoms of this additional ring underwent further transformations resulting in the formation of a six-membered ring produced by the addition of a carbon atom to the dihydropyrazoloacridine ring. Furthermore, it was observed that positions 2 and 4 of ledakrin's acridine ring are susceptible to nucleophilic substitution as revealed by the studies with dithiothreitol. Additionally, although most products from the reduction of ledakrin were extremely unstable, 1-aminoacridinone, produced enzymatically and with dithiothreitol, exhibited persistent stability under the studied conditions.

Animals↗
PubMed2002

Biological effects of rutin on the survival of Escherichia coli AB1157 and on the electrophoretic mobility of plasmid PUC 9.1 DNA.

The use of natural products as medicines is growing in the world. The rutin, a compound isolated from Ruta graveolens, is a flavonoid, which has been suggested to have antioxidant properties and to reduce the triacylglycerol levels. In this study, plasmid desoxyribonucleic acid (DNA) was exposed to rutin (0.33, 10, 20, 30 microg/ml) in presence of stannous chloride (SnCl2), a reducing agent widely used to obtain radiopharmaceuticals labeled with technetium-99m. Samples of the plasmid DNA were analyzed through agarose gel electrophoresis. E. coli AB1157 culture was also incubated with rutin (3, 30, 50, 100 microg/ml) and the survival fractions were calculated. The results show that the rutin, in these concentrations, is not capable of: i/ damaging the DNA, ii/ protecting the DNA from the SnCl2 redox action, and iii/ inactivating the E. coli AB1157 culture. The analysis of our data indicates that rutin do not present toxic activity in the evaluated systems.

Antioxidants↗
PubMed1999

Development of a lyophilized kit formulation for labeling of DNA probes with 99mTc.

DNA fragments such as oligodeoxynucleotides (ODNs) are under investigation for a possible utilization in nuclear medicine. Until now, experiments on 99mTc-labeled ODNs in vitro or in vivo have required the application of time-consuming procedures to obtain and control the purity of the radiolabeled compound. A lyophilized labeling kit would ease and improve the reproducibility in further investigations with this class of promising biomolecules; therefore a study was initiated to evaluate the suitability of conjugates of ODNs and a bifunctional chelating agent to be part of lyophilized kit formulations. We report here the development of the first kit for one-step labeling of oligonucleotides with 99mTc. The formulation comprises 250-500 pmol S-benzoyl-mercaptoacetyldiglycine (MAG2)-ODN phosphorothioate conjugate, 5 mg potassium sodium tartrate tetrahydrate and 100 microg stannous chloride dihydrate in a lyophilized kit. Labeling yields above 90% were reproducibly achieved after addition of 0.1-1 GBq pertechnetate and subsequent heating in a boiling water bath. Once formed, the 99mTc-MAG2-ODN complexes were stable for at least 24 h. The shelf life of the kits is at least 10 weeks when stored protected from light at room temperature, but even kits stored at 40 degrees C gave labeling yields above 90% after 10 weeks.

Chromatography, High Pressure Liquid↗
PubMed1997

Heme oxygenase induction with attenuation of experimentally induced corneal inflammation.

Heme oxygenase (HO), by catabolizing heme to bile pigments, down-regulates cellular levels of heme and hemeproteins; certain of the latter, i.e. cytochrome P450s, generate pro-inflammatory products from endogenous substrates. Two HO isozymes, the products of distinct genes, have been described; HO-1 is the inducible one, whereas HO-2 is believed to be constitutively expressed. We studied the inducing effects of several metal compounds [CoCl2, SnCl2, ZnCl2, heme, and cobalt protoporphyrin (CoPP)] on HO-1 mRNA content and enzyme activity in cultures of rabbit corneal epithelial (RCE) cells; these metal compounds are known to induce HO in other tissues. Additionally, we studied HO-1 expression in an experimental model of ocular inflammation produced in rabbit corneas by extended contact lens wear, and the relation of HO expression to the induced inflammatory process. SnCl2 added to RCE cells in vitro produced marked time- and concentration-dependent increases in HO-1 mRNA and HO-1 enzyme activity; CoCl2, ZnCl2, and CoPP were inducers of HO as well, though to a lesser degree than SnCl2. Corneas treated for 6 days with contact lenses impregnated with SnCl2 displayed substantially less corneal inflammation, swelling, and new vessel invasion than did controls; attenuation of ocular inflammation was paralleled by SnCl2-induced increases in HO mRNA and HO activity in corneal epithelial cells from treated eyes. It is suggested that amelioration of the inflammatory response produced by extended contact lens wear is due, in part, to the induction of high levels of HO-1 activity by SnCl2, which results in diminished production of pro-inflammatory mediators generated through heme-dependent metabolic processes. Regulation of HO activity in this manner may have clinical applications.

Animals↗
PubMed1991

Technetium-99m labeled monoclonal antibodies: evaluation of reducing agents.

We have evaluated five compounds, stannous chloride (SnCl2), 2-mercaptoethanol (2-ME), dithiothreitol (DTT), dithioerythritol (DTE), and ascorbic acid (AA) to reduce monoclonal antibody MoAb (disulfide groups and compared their efficacy for labeling MoAbs with 99mTc. The reduction of 99mTc with dithionite at pH 11 was nearly quantitative. The use of AA, at a molar ratio of 3500:1, for three IgG and three IgM antibodies examined, gave a labeling efficiency greater than 95%. Hence no purification was needed. The immunospecificity of AA preparations determined by specific antigen assay was 84 +/- 1% for an IgM and 82.6 +/- 1.1% for an IgG, highest among all agents tested. The stability of the tracer was evaluated by challenging the product with such 99mTc avid agents as cysteine, DTPA, and human serum albumin. By HPLC analysis, no 99mTc was transchelated using chelating agent to protein molar ratios as high as 500:1. In two separate groups of five mice each, the liver uptake at 4 h post injection averaged 6.8 +/- 2.9% per gram for 125I-TNT-1 (IgG) and 6 +/- 5.1% per gram for the same MoAb labeled with 99mTc using AA. The AA technique promises to label antibodies with 99mTc and perhaps with 186Re, by a simple "kit" procedure.

Antibodies, Monoclonal↗
PubMed2003

Trace determination of organotin compounds in water, sediment and mussel samples by low-pressure gas chromatography coupled to tandem mass spectrometry.

A fast method for the determination of eight organotin compounds (OTs), monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), tetrabutyltin (TeBT), monophenyltin (MPhT), diphenyltin (DPhT), triphenyltin (TPhT) and tetraphenyltin (TePhT), in water, sediments and mussels, was developed using low-pressure gas chromatography/tandem mass spectrometry (LPGC/MS/MS). The method is based on sodium diethyldithiocarbamate (DDTC) complexation of the ionic organotins, followed by extraction of the target matrices and derivatization by a Grignard reagent, as described in a previously published method for water samples. Solid-phase extraction was selected as extraction method from water samples after comparison with liquid-liquid extraction, but extraction of the OTs from sediment and mussel samples was performed using toluene. Matrix-matched calibration standards were used to minimize matrix effects. The analytical process was validated by the analysis of spiked blank samples. Performance characteristics such as linearity, detection limit (LOD), quantitation limit (LOQ), precision, and recovery were determined. Recoveries of OTs in spiked matrices ranged from 86-108% in water and from 78-110% in sediments and mussels, with precision values lower than 18%. Detection limits ranged from 0.1-9.6 ng L(-1) in water, and 0.03-6.10 microg kg(-1) in the other matrices. The present implementation of LPGC rather than conventional capillary GC permitted use of large-volume injection and reduced analysis time by a factor of two. The proposed methodology was applied to the determination of OTs in real samples of water, marine sediments and mussels from the west coast of the Mediterranean Sea (Spain).

Animals↗
PubMed2005

[Effect of Hypericum perforatum extract on in vitro labelling of blood elements with technetium-99m and on biodisponibility of sodium pertechnetate in Wistar rats].

PURPOSE: To evaluate the effect of a hiperico extract (Hypericum perforatum) on the labeling of blood elements with technetium-99m (99mTc) and in the bioavailability of the radiopharmaceutical sodium pertechnetate in Wistar rats. METHODS: Blood (heparinized) withdrawn from Wistar rats is incubated with a hiperico extract, with a stannous cloride and with 99mTc, as sodium pertechnetate (99mTcONa). Plasma (P) and cells (C) are isolated by centrifugation. Samples of P and C are also precipitated with trichloroacetic acid (TCA 5%) and soluble (FS-P; FS-C) and isoluble (FI-P; FI-C) fractions are separated. In the bioavailability analysis, the extract or NaCl 0.9% solution is administrated into Wistar rats (gavage) during 15 days. Sodium pertechnetate was administered and after 10 min, the animals are sacrificed, the organs were isolated, the radioactivity determined in a well counter, and the percentages of radioactivity per gram (%ATI/g) in the organs are calculated. RESULTS: The hiperico extract decreasedsignificantly (P < 0.05) the %ATI in the cells, cellular insoluble fraction and plasma insoluble fraction. The biodistribution was significantly (P < 0.01) decreased in bone, muscle and thyroid and significantly (P < 0.05) increased in pancreas. CONCLUSION: The analysis of the results indicates that in studied extract should have substances that should oxidize the stannous ion, reducing the fixation of the 99mTc on the erythrocytes and plasma and cellular proteins. Moreover, it could produce metabolic alterations with influence in the uptake of the radiopharmaceutical 99mTcO4Na in bone, muscle, pancreas and thyroid.

Animals↗
PubMed2000

Splenic function in sickle cell anemia patients in Qatif, Saudi Arabia.

A prospective study was conducted to study the splenic function among sickle cell anemia (SCA) patients in Qatif (Eastern Province of Saudi Arabia). Seventy-seven patients (30 children and 47 adults aged 2-57 years) were included. (99m)Tc stannous colloid liver-spleen scan was done for each patient during steady state. The splenic function was graded from 0 to 4 in relation to liver uptake. Seventy percent of our patients showed evidence of splenic hypofunction, and most of them (83%) had severe hyposplenism. Up to the age of 4 years, only 17% of the children showed evidence of functional hyposplenism, but by the age of 10 years >50% were hyposplenic. Most of the hyposplenic children had functional hyposplenism, whereas only one-third of hyposplenic adults had autosplenectomy. There was no effect of level of HbF on the frequency of hyposplenism, but on the other hand low MCV seems to be protective against hyposplenism. A significant number of adult SCA patients have clinically enlarged spleens, and almost a third have normally functioning spleens. Because of the low prevalence of hyposplenism in children younger than 4 years of age, routine penicillin prophylaxis is probably not indicated in this population, an issue which needs further evaluation.

Adolescent↗
PubMed2002

Kinetics of heterogeneous hybridization on indium tin oxide surfaces with and without an applied potential.

The rate of hybridization of oligonucleotide target sequences to chemically immobilized oligonucleotide probes has been studied both with and without an electrical field. The probe size was 20-24 nucleotides (nt) while the target size ranged from 157 to 864 nt. In agreement with previous studies, complete hybridization under normal conditions required 10-30 hours, depending on target size. The kinetics were characterized by a characteristic lag time followed by an asymptotic rise to the final value. In contrast, with an applied electrical field, all but the largest target hybridized in about 10 min while the longest hybridized within 1 h. Deleterious electrode reactions were avoided by close spacing of the anode and cathode and application of very small voltages. Our results suggest that probes and targets orient flat on the surface. A model is suggested to explain the kinetics observed that involves a series of surface states between initial target arrival and final hybridized state. Our results show that the electric field accelerated hybrid capture of solution-phase targets by surface-bound probes. This approach may have implications for enhancing array-based hybrid capture for mutation detection, copy number determination and/or gene expression profiling.

DNA↗