Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Vanadium 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 541 records · Page 30Linked to original sources
PubMed2000

ENDOR studies of VO2+: probing protein-metal ion interactions in nephrocalcin.

Nephrocalcin inhibits the growth of calcium oxalate monohydrate crystals in the mammalian kidney. Isoforms A and B contain three equivalents of gamma-carboxyglutamic acid (Gla) residues implicated in Ca2+-binding and exhibit strong inhibitor properties and high Ca2+-binding affinity (Kd approximately 10(-8) M). Isoforms C and D lack these properties and exhibit low Ca2+-binding affinity (Kd approximately 10(-6) M). With VO2+ as a structural probe, electron paramagnetic resonance (EPR) studies of the Ca2+-binding sites of isoforms B and D showed that VO2+ binds competitively with a metal ion:protein stoichiometry of 4:1. EPR spectral parameters of the VO2+ ion were consistent with only equatorial oxygen-donor ligands. EPR and angle-selected electron nuclear double resonance (ENDOR) spectra showed two equatorially positioned, metal coordinating waters in isoform D while in isoform B no ligands undergoing hydrogen exchange were found. Since isoform D showed no evidence for axially coordinated water, similarly to isoform B, it is likely that the protein residues occupying the axial sites are identical in both proteins. ENDOR spectra of VO2+-complexes of isoforms B and D were compared to spectra of the VO2+-complex with alpha-ethylmalonic acid (EMA), a molecular mimic of Gla. Spectra of the VO2+-complex of EMA showed axial water located trans to the V=O bond and outer shell water hydrogen-bonded to the vanadyl oxygen, consistent with the X-ray structure of Ca(EMA)2. We, therefore, conclude that the spatial disposition of carboxylate groups of Gla residues coordinating Ca2+ in isoforms A and B must differ from that observed in the crystal structure of Ca(EMA)2.

Animals↗
PubMed2002

Effect of TiO2 surface properties on the SCR activity of NOx emission abatement catalyst.

NOx emission abatement catalysts V2O5 supported on various TiO2 including anatase, rutile and mixture of both were investigated with various physico-chemical measurements such as BET, NH3-TPD, NARP, XRD and so on, and the effect of TiO2 surface properties on the SCR (selective catalytic reduction) activity of V2O5/TiO2 catalysts was studied. It was found that the TiO2 surface properties had strong effect on the SCR activity of V2O5/TiO2 catalysts. The stronger acidic property resulted in the higher exposure of active sites as well as the higher SCR activity.

Air Pollutants↗
PubMed1992

Differential sensitivity of the brain ATP-dependent and GTP-dependent succinyl-CoA synthetase to vanadium ions. Developmental aspects.

We have recently found that both vanadate and vanadyl inhibit ATP-dependent succinyl-CoA synthetase (A-SCS) solubilized from the rat brain mitochondria. Aim of the present study was to estimate a proportion of A-SCS to G-SCS in adult and 5-day-old rat brain and their susceptibility to vanadium ions. The G-SCS to A-SCS ratio of 5-day-old brains was by 196% higher than that in adults. This is in accordance with previous observation that G-SCS is high in tissues metabolizing ketone bodies. Both G-SCS and A-SCS differ in their susceptibility towards vanadium ions. A-SCS of adult brain was more sensitive to vanadate (IC 50 1.6.10(-5) mol.l-1) than was G-SCS (IC 50 6.2.10(-5) mol.l-1). On the contrary G-SCS was more sensitive to vanadyl (IC 50 3.5.10(-4) mol.l-1) than was A-SCS (IC 50 9.0.10(-4) mol.l-1). Also autophosphorylation of G-SCS a-subunit was more resistant to vanadate than A-SCS. In contrast to the adult SCS forms, almost equal susceptibility of A-SCS and G-SCS to vanadyl and vanadate was observed in infant brains. The results suggest some structural (functional) differences between two SCS forms in adults and also between infant and adult G-SCS.

Aging↗
PubMed2002

[Calculation of spectroscopic properties of Tm:YVO4 crystals].

Sigma and pi polarized absorption spectra of Tm:YVO4 crystal have been measured at room temperature. Considering the difference of the sigma and pi polarized absorption spectra and the changing of the refractive index with different wavelengths, we calculate the intensity parameters of Tm3+ in crystal YVO4 which are omega 2 = 1.9416 x 10(-20) (cm2), omega 4 = 0.1568 x 10(-20) (cm2), omega 6 = 0.3963 x 10(-20) (cm2) by Judd-Ofelt theory. The spectra characteristic parameters, such as radiative transition rates, luminescence branching ratio, total radiative lifetime and integral cross-section are also calculated. The results show that the spontaneous rate of the transition 1D2-->3F4 is much higher than that of the transition 1D2 to other levels.

Chemical Phenomena↗
PubMed2001

[Raman spectra for YVO4 and Nd:YVO4 crystals].

In this paper, the measured Raman spectra of YVO4 and Nd: YVO4 crystals were reported. These results give a clear information on the phonon energy spectra, these are several discrete phonons in low energy region, then nothing shows up in a large space from 500-800 cm-1 and main portion of phonon spectra is distributed in the region of 800-900 cm-1. Based on the group theory, the symmetries for Raman lines can be deduced, and they are almost due to the vibration of VO(4)3- ion. The effect of uneven distribution for phonon spectra on the optical transition and laser performance are discussed. The restraint action of doped ion on the high energy phonon is found.

Crystallization↗
PubMed2003

[Research on optical property of phase transition VO2 films].

Optical transmission spectra of VO2 films on glass, fused silica, and sapphire were recorded and analyzed during heating process. Thermally induced phase transition of VO2 films occurred at a certain temperature, associated with abrupt changes in optical properties. The transition temperature and the contrast of the optical properties depended on the substrate and the deposit method used. The change in transmittance delta T at 5 microns of VO2 films deposited on sapphire by RF magnetron sputtering was 70%, and the corresponding relative change delta T/TRT was 94%. For the VO2 films deposited on glass by RF magnetron sputtering, delta T at 2.5 microns was 64.2%, and delta T/TRT was as high as 98%.

Aluminum Oxide↗
PubMed1992

[Respiratory disease morbidity in workers in ferrovanadium production].

Links between the occupational factors of iron-vanadium production and respiratory morbidity in workers are revealed in the article. The work conditions of such occupational groups as preparatory workers (preparing and splitting of a furnace charge, slag grinding), roast workers, hydro- and electric metallurgy employees are evaluated by hygienic methods. Structure, relative risk and the standardized risk of respiratory diseases formation were shown in different occupational and age groups.

Adult↗
PubMed1992

Administration of vanadyl sulfate by gavage does not normalize blood glucose levels in streptozotocin-induced diabetic rats.

Vanadyl sulfate trihydrate was given by gavage to streptozotocin-induced diabetic rats for 21 days at doses of 0, 25, 50, or 75 mg/kg/day. In marked contrast to the reduction in plasma glucose observed in diabetic animals given vanadyl sulfate via drinking water, diabetic rats given vanadyl by gavage were not characterized by normoglycemia. Similarly, in contrast to the normalizing effect of vanadyl in drinking water, vanadyl by gavage had only a minimal influence on diabetes associated hyperphagia and polydipsia. Despite the lack of marked effect of vanadyl by gavage on the above parameters, tissue vanadium accumulation in the gavaged rats was similar to that reported for rats given vanadium by drinking water. The present results (taken together with previous data) show that the administration of vanadium by gavage is not a viable alternative to the use of insulin in diabetes treatment.

Animals↗
PubMed2005

[Therapeutic potential of vanadium in treating diabetes mellitus].

The patients suffered from diabetes mellitus (DM) are increasing year by year through the world. DM is classified into two groups, insulin-dependent type 1 and non-insulin-dependent type 2. Recent research has demonstrated that vanadate (VO3-, oxidation state+5) and vanadyl (VO2+, oxidation state+4) both mimic various actions of insulin in cellular systems. In 1985, vanadate given orally as a drinking water to streptozotocin-induced hyperglycemic type 1 diabetic rats (STZ-rats) was found to reduce the high levels of blood glucose down to normal levels and ameliorated many of the aberrations induced by hyperglycemia. In 1990, we proposed first orally active vanadyl complexes such as vanadyl-cysteine methylester and vanadyl-oxalate complexes in STZ-rats. Since then, we have developed orally active vanadyl complexes with different coordination modes. Among them, vanadyl-picolinate complexes with VO(N2O2) coordination mode were found to be potent orally active insulin-mimetic agents, on the basis of the results on in vitro test using isolated rat adipocytes with respect to the inhibition of the release of free fatty acids (FFA) from the cells and in vivo evaluation (intraperitoneal injection and oral administration) in STZ-rats. Based on the results, the usefulness of vanadium complexes in treating and preventing DM has been revealed, proposing a possible action mechanism.

Adipocytes↗
PubMed2005

[Infrared spectra of polyoxometalates].

The infrared spectra of polyoxometalates are addressed. The vibration frequencies of some synthesized polyoxometalates in recent years are emphasized. It was found that the infrared spectra of polyoxometalates result from stretch vibration frequency of the metal-oxygen, and 1 100-400 cm(-1) is the region of the characteristic absorption peak. The infrared spectrum contains information about the symmetry of polyoxoanion as well. As an analytical means, the infrared spectrum can be used to distinguish heteropolyanion and provide information on structure.

Models, Chemical↗
PubMed2005

[Effect of vanadyl sulfate (VOSO4) on the production of flavonoids by the culture Ononis arvensis L. in vitro].

The study tested the effect of vanadyl (IV) sulfate (VOSO4) on the production of flavonoids in the callus and suspension culture of Ononis anrensis L. (Fabaceae). This substance proved to be a good abiotic elicitor for an increase in the production of secondary substances (flavonoids) in the culture of Ononis arvensis L. in vitro. The maximal increase in the formation of flavonoids took place in the callus culture after 24-hour elicitation with VOSO4 in a concentration of 1.227 .10-4 mol/l by 313% in comparison with the control and in the suspension culture in a concentration of 1.227 .10-6 mol/l after 48-hour action of the elicitor by 485% in comparison with the control.

Fabaceae↗
PubMed2005

Particle size and composition related to adverse health effects in aged, sensitive rats.

Small increases in concentrations of ambient particulate matter (PM*) have been linked to adverse health effects, especially in older people and people with preexisting respiratory disease. Some epidemiologic studies have shown the association to be stronger with PM less than 2.5 microm in aerodynamic diameter (PM2.5) than with PM less than 10 microm in aerodynamic diameter (PM10). Some scientists and regulators suggest that 2.5 microm might be an arbitrary cutoff and that the effects might be more pronounced for PM less than 0.1 microm in aerodynamic diameter (ultrafine PM). Our first aim was to determine the relation between size of respirable particles and particle toxicity, as well as the health effects of short-term increases (spikes) in particle concentration against backgrounds of relatively low or high baseline exposures. Our second aim was to determine the effect of spikes in concentration of fine particles (0.7 microm in mass median aerodynamic diameter [MMAD]) and ultrafine particles (35 nm in count median diameter [CMD]) of disparate composition: vanadium pentoxide (V2O5) and carbon black. The relative toxicity of these particles was determined in aged rats with mild pulmonary inflammation induced by instilled endotoxin. Our third aim was to determine the influence of age (aged vs young adult) on particle-induced toxicity in these rats.

Age Factors↗
PubMed2006

[Influence of treatment of vanadium electrophoresis on certainbio-chemical and immunological indicators in patients with prolonged cases of pneumonia].

Inflammatory process in bronchial and lung tissues during the prolonged cases of pneumonia causes failure of immunological system and depression of glucocorticoid and androgenic functions of cortex of kidneys. That's why it's important to find new, more effective anti-inflammation means causing reduction and even disappearance of inflammatory process in bronchi and lungs, influencing immunological system positively and normalizing its condition and cortex of kidneys. 65 patients of age from 25 till 64 were examined, from which 31 had nidal prolonged pneumonia and 39 had interstitial prolonged pneumonia. It was stated that treatment with vanadium electrophoresis causes reduction and even disappearance of the inflammatory process in bronchi and lungs in the patients with prolonged pneumonia, leading to the strengthening of cellular chain of the immunity, nonspecific resistance of the organism, has a desensitisation influence, strengthens glucorticoid and androgenic functions of cortex of kidneys, normalises interchange of proteins and humoral immunity, increased substance (contents) of vanadium in the whole blood. Indicated positive results were more significant in the cases of nidal prolonged pneumonia.

Adult↗
PubMed1991

[Transplacental passage of vanadium after treatment with vanadium pentoxide in Wistar rat].

The passage of vanadium pentoxide across the placenta into the embryo/fetus was investigated by analyzing the vanadium content in embryo/fetus at various intervals between 1 h and 48 h after treatment of pregnant Wistar rats with single dose of the V2O5 (5mg/kg) on days 16-18 of gestation, at 4h after treatment of pregnant rats with single dose of V2O5 (5mg/kg) on day 12, and at 120 h after treatment of pregnant rats with dose of V2O5 0.33, 1.0, 3.0 mg/kg on days 6 through 15. The V concentration was determined by catalytic polarography. At after treatment on day 12, the V concentrations in maternal blood, placenta and embryos were elevated in comparison with those of the untreated group. At 4-48 h after treatment on days 16-18, the V concentrations in placenta and fetuses were elevated in comparison with those of the untreated group. The V concentration at 4 h after treatment in various tissues is the highest one among different time points. On days 16-18, 4 h after treatment, the V concentration in placenta was elevated in comparison with that on day 12 of gestation, but the V concentration in embryo/fetus was decreased. At 120 h after treatment on days 6-15, the V concentration in fetus is still high in comparison with that of the untreated group. The V content of fetus varied according to doses, suggesting that embryo/fetus accumulates vanadium. The results showed that vanadium can pass through the placental barrier and enter the embryo/fetus during the embryonal organogenesis in rat, but placenta accumulates vanadium, and the barrier action increases with placental maturity.

Animals↗
PubMed1991

[A study on developmental toxicity of vanadium pentoxide in NIH mice].

There is no general agreement yet about the teratogenic effects or developmental toxicity of vanadium in animal studies. This is a report on developmental toxicity in NIH mice following injection of vanadium pentoxide (V2O5, 5 mg/kg body weight, i.p.) at different times of gestation (on days 1-5, 6-15, 7, 8, 9, 10, 11, 14-17 of gestation). No adverse effects of V2O5 on pre-implantation and implantation were noted, and neither were teratogenicity and premature birth. However, there was toxic effect on embryofetus. Increased frequency of resorption or fetal death on days 6-15, 7, 14-17 of gestation were observed. Delayed ossification of bones was noted on days 6-15, 8, 10, 14-17 of gestation. These results suggest that V2O5 may be a weak developmental toxicant but not a teratogen in NIH mice. In addition, this paper reports the developmental toxicity, especially teratogenicity of N, N'-methylene-bis (2-amino-1, 3, 4-thiadiazole) which was used as the positive control in NIH mice.

Animals↗