Wyniki wyszukiwania - Biblioteka Nauki

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Insulinonaśladowcze i przeciwcukrzycowe właściwości związków wanadu

100%

Kupcewicz B. , Budzisz E.

Wiadomości Chemiczne

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2009

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tom [Z] 63, 1-2

85-106

EN

Vanadium is a trace element, which may be beneficial for human and developed as clinically useful metallopharmaceutical. Over the last 20 years a wide range of medicinal aspects of various compounds of vanadium have been investigated and documented [10-21]. Vanadium displays relevant biological actions such as insulin-mimicking or spermicidal [5-7] as well as it shows antitumor activity [3, 4]. This review has focused on vanadium inorganic compounds and organic complexes which have insulin-mimetic and anti-diabetic properties. Vanadium-based therapeutic agents belong to the class of compounds in which active is the metal ion and the ligand plays only an ancillary role - delivers active metal to target tissues what may have important implications for the bioavailability and pharmacokinetic properties of vanadium. Vanadium salts such as oxovanadium(IV) sulphate (vanadyl sulphate) VOSO4 or sodium orthovanadate(V) NaVO3 and some vanadium organic complexes are potent insulin-mimetic compounds for treating both type I and type II in animal model, cell culture systems and human diabetes. Many studies have demonstrated that the oral administration of vanadium compounds normalizes blood glucose levels, stimulates glucose intake into cells and causes inhibition of glikoneogenesis and lypolysis. Vanadyl sulphate and other simple salts are effective but unfortunately have poor uptake through gastrointestinal system and have some toxic effects. Complexation with organic ligands may improve vanadium efficacy and decrease toxic side effects. Since 1990 several vanadium compounds (vanadyl, vanadate and peroxovanadate) with organic ligands have been proposed for this purpose. This review describes vanadyl complexes with ligand such as maltol and its derivatives, picolinate ion, flavonoids, sulphur containing compounds and hypoglycemic drugs (metformine and thiazolidenodiones). In recent years some VO(IV) complexes with maltol - bis(maltolato)oxovanadium (BMOV) and ethylmaltol (BEOV) have been proposed for clinical use in humans. BEOV has in 2000 completed I-st phase of human clinical trials. To asses the insulinomimetic and anti-diabetic activities of vanadium(IV) complexes several in vitro- and in vivo systems have been performed. Hypoglycemic and glucose normalizing activity were investigated in vivo in both type I and II diabetic animal (mice and rats) models. In vitro insulinomimetic activity was examined in isolated rat adipocytes. Alternatively for improving bioavailability and anti-diabetic efficacy of vanadium several novel drug delivery systems such as chitosan-hydrogel or enteric-coated capluses containing vanadium [55, 56, 60] compounds have been tested.

2

Pentatlenek wanadu : metoda oznaczania

75%

Gawęda E.

Podstawy i Metody Oceny Środowiska Pracy

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2000

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tom Nr 3 (25)

130--133

PL

Pentatlenek wanadu (wanadu pięciotlenek), najpopularniejszy ze związków wanadu, jest to czerwono żółty lub czerwony proszek, który występuje w formie amorficznej lub krystalicznej. Temperatura topnienia tego związku wynosi 690 °C, temperatura wrzenia 1750 °C (z rozkładem), a gęstość 3,36 g/cm3. W wodzie rozpuszcza się niezbyt dobrze (0,8 g/1), dobrze rozpuszcza się w kwasach i zasadach, nic rozpuszcza się w alkoholu etylowym. Otrzymuje się go przez prażenie wanadanu amonowego w długotrwałym utrzymywaniu w strumieniu chlorowodoru w temperaturze 400 -s- 500 °C. Pentatlenek wanadu jest ważnym katalizatorem w produkcji kwasu siarkowego metodą kontaktową, utlenianiu naftalenu do bezwodnika ftalowego i innych procesach utleniania. W przemyśle szklarskim jest stosowany do produkcji szkła absorbującego promieniowanie nadfioletowe. Narażenie na działanie tego związku występuje również podczas oczyszczania pieców w elektrociepłowniach opalanych mazutem. Pentatlenek wanadu jest z toksykologicznego punktu widzenia najważniejszym związkiem wanadu, co wynika zarówno z jego najszerszego zastosowania, jak i najsilniejszego działania toksycznego. Wchłaniany głównie w drogach oddechowych wywołuje zarówno zatrucia ostre, jak i przewlekłe. Ostre zatrucia inhalacyjne prowadzą do stanów zapalnych gardła, oskrzeli i płuc objawiających się silnym kaszlem, który może doprowadzić do krwotoku. Zatrucia przewlekłe powodują poza wymienionymi objawami wiele innych, jak np.: bóle i zawroty głowy, podwyższenie ciśnienia krwi, bladość skóry i drżenie rąk. Ponadto obserwowano również zmiany we krwi - podwyższenie liczby erytrocytów i w moczu - pojawienie się krwinek czerwonych lub białka.

EN

The method is based on stopping vanadium pentaoxide on membranę filter and extraction of the compound dust with 0,01 NaOH. Yanadium pentaoxide in the solution is determinated as vanadium by flame atomic absorption spectrophotometry. The detection limit of the method is 0,009 mg/m3.

3

Effects of thermal treatment on magnetic properties of Ni2FeV3O11-.delta compound

63%

Guskos N. , Typek J. , Żołnierkiewicz G. , Błońska-Tabero A. , Los S. , Kempiński W.

Materials Science Poland

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2006

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tom Vol. 24, No. 4

983--990

EN

Ni2FeV3O11-.delat samples have been synthesized by the solid-state reaction method using two different heat treatment processes (samples of the type A and B). The XRD measurements have shown the same diffraction patterns for both types of samples. The temperature dependences of the electron paramagnetic resonance (EPR) spectra have been recorded for the two types of thermal annealing processes of Ni 2FeV3O11-.delta. Strong differences have been observed in the EPR spectra of both types of Ni2FeV3O 11-.delta. An intense EPR line has been recorded at high temperatures; it is suggested that the line is associated with oxygen-vanadium clusters (ferromagnetic ordering). The linewidth, resonance field and integrated intensity of the EPR spectra have shown a strong temperature dependence down to 200 K. Additionally, in one sample a very broad EPR line of Fe3+ ions appeared at low temperatures while at high temperatures this line was overlapped by the other line. The temperature dependence of the integrated intensity of this broad line has shown the Curie-Weiss behaviour. In the vanadate oxide materials with two strong magnetic ions in the structure (iron(III) and nickel(II)), the spectrum of the Fe3+ ions is not observed. Different oxygen deficiency processes could explain the differences in the EPR spectra of both types of Ni2FeV3O 11-.delta compounds.

4

Związki wanadu i chromu jako potencjalne insulino-mime tyki wykorzystywane w leczeniu cukrzycy

63%

Drzeżdżon J. , Malinowski J. , Zych D. , Jacewicz D.

Wiadomości Chemiczne

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2019

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tom [Z] 73, 11-12

753--775

EN

The report focuses on the antidiabetic, also termed insulin-like, effect of various vanadium and chromium derivatives, proposed mechanisms of their activity, their use in in vivo and in vitro studies, as well as in diabetic patients, their toxicity and effectiveness in controlling clinical signs of diabetes. Studies indicate that compounds of vanadium and chromium is necessary for regulation of carbohydrate and lipid metabolism mainly due to increasing the number of insulin receptors and its activation by phosphorylation. Some authors believe that compounds of chromium(III) deficiency can lead to glucose intolerance and symptoms of type 2 diabetes. However, due to methodological limitations of many clinical studies, the statements of major diabetes associations concerning recommendation of various vanadium and chromium derivatives supplementation in individuals with diabetes and obesity still remains negative. Additional studies are urgently needed to elucidate the mechanism of action of chromium and vanadium compounds and its role in the prevention and control of diabetes.