New complexes of nickel (II) have been synthesized in the reaction mixture of nickel (II) acetate and 4-hydroxy-2-oxo-2Hchromene-3-carboxamide. Bis(4-hydroxy-2-oxo-2H-chromene-3carboxamidato-O,O)nickel (II) and diaquabis(4-hydroxy-2-oxo-2Hchromene-3-carboxamidato-O,O)nickel (II) were characterized by elemental analysis, IR spectroscopy and ESI mass spectrometry. Elemental analysis and mass spec...

Twenty-nine samples of high-purity nickel metals, reagent salts and minerals, collected from worldwide sources, have been examined by high-precision isotope ratio mass spectrometry for their nickel isotopic composition. These materials were compared directly with SRM 986, certified isotopie standard for nickel, using identical measurement techniques and the same instrumentation. This survey sho...

Nickel and cobalt are often responsible for metal-induced allergic contact dermatitis. With the increasing use of cell phones, we observed an increase in cases reports on telephone-related allergic contact dermatitis. The present study evaluated nickel and cobalt release from mobile phones used in Brazil. We evaluated devices of 6 brands and 20 different models using nickel and cobalt allergy s...

Potential relationships between the development of nickel allergy and previous ear piercing or orthodontic treatment with nickel-containing appliances were studied in 294 patients. We found 77 (31.2%) of 247 patients with pierced ears were allergic to nickel compared to only three (6.4%) patients without pierced ears (p = 0.001), which confirms earlier suggestions that nickel allergy (as assess...

Keys are a significant source of exposure to metal allergens and can be a relevant problem for nickel-allergic individuals. This study aimed to perform nickel and cobalt spot testing among the 5 most common Brazilian brands of keys. Among the tested keys, 100% showed positive result to nickel spot test, 83,3% presented strong positive reaction. 50% exhibited cobalt release as well. Nickel relea...

A model of the self-discharge process of a nickel-hydrogen cell is presented. The model includes three electrochemical reactions on the nickel electrode (reduction of nickel oxyhydroxide, oxidation of hydrogen, and oxidation of hydroxyl ion to form oxygen) and two electrochemical reactions on the hydrogen electrode (reduction of oxygen and oxidation of hydrogen). The self-discharge pressure pro...

Nickel compounds are prime inducers of contact allergy reactions in humans. To identify the signal transduction pathways mediating the cellular responses to nickel and to elucidate their hierarchy, we performed Affymetrix gene profiling using human primary endothelial cells, which strongly respond to nickel stimulation. Overall, we found 258 significantly modulated transcripts, comprising 140 u...

Nickel is a metal of widespread distribution in the environment: there are almost 100 minerals of which it is an essential constituent and which have many industrial and commercial uses. Nickel and nickel compounds belong to the classic noxious agents encountered in industry but are also known to affect non-occupationally exposed individuals. The general population may be exposed to nickel in t...

Primary endothelial cells are fully resistant to TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. Here, we demonstrate that certain environmental conditions, such as exposure to the widespread allergen nickel, can dramatically increase the susceptibility of naturally resistant primary endothelial cells or keratinocytes to TRAIL-induced apoptosis. While nickel treatment increase...

The aim of this study was to investigate the role of nickel in orthodontic treatment-induced gingival hyperplasia. The nickel concentration in gingival tissues with and without overgrowth, histopathology of gingival overgrowth, and epithelial cell proliferation response to different nickel concentrations were analysed. Ten patients receiving orthodontic therapy (eight females and two males, mea...