Copper toxicity, oxidative stress, and antioxidant nutrients.

Review of the biological properties and toxicity of bee propolis (propolis)

Copper (Cu) is a vital mineral essential for many biological processes. The vast majority of all Cu in healthy humans is associated with enzyme prosthetic groups or bound to proteins. Cu homeostasis is tightly regulated through a complex system of Cu transporters and chaperone proteins. Excess or toxicity of Cu, which is associated with the pathogenesis of hepatic disorder, neurodegenerative changes and other disease conditions, can occur when Cu homeostasis is disrupted. The capacity to initiate oxidative damage is most commonly attributed to Cu-induced cellular toxicity. Recently, altered cellular events, including lipid metabolism, gene expression, alpha-synuclein aggregation, activation of acidic sphingomyelinase and release of ceramide, and temporal and spatial distribution of Cu in hepatocytes, as well as Cu-protein interaction in the nerve system, have been suggested to play a role in Cu toxicity. However, whether these changes are independent of, or secondary to, an altered cellular redox state of Cu remain to be elucidated.

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Copper: toxicological relevance and mechanisms

Palladium--a Review of Exposure and Effects to Human Health

Background: In dentistry, allergic reactions to Ti implants have not been studied, nor considered by professionals. Placing permanent metal dental implants in allergic patients can provoke type IV or I reactions. Several symptoms have been described, from skin rashes and implant failure, to non-specific immune suppression. Objective: Our objective was to evaluate the presence of titanium allergy by the anamnesis and examination of patients, together with the selective use of cutaneous and epicutaneous testing, in patients treated with or intending to receive dental implants of such material. Material and methods: Thirty-five subjects out of 1500 implant patients treated and/or examined (2002‐2004) were selected for Ti allergy analysis. Sixteen presented allergic symptoms after implant placement or unexplained implant failures [allergy compatible response group (ACRG)], while 19 had a history of other allergies, or were heavily Ti exposed during implant surgeries or had explained implant failures [predisposing factors group (PFG)]. Thirty-five controls were randomly selected (CG) in the Allergy Centre. Cutaneous and epicutaneous tests were carried out. Results: Nine out of the 1500 patients displayed positive ( þ) reactions to Ti allergy tests (0.6%): eight in the ACRG (50%), one in the PFG (5.3%)(P ¼0.009) and zero in the control group. Five positives were unexplained implant failures (five out of eight). Conclusions: Ti allergy can be detected in dental implant patients, even though its estimated prevalence is low (0.6%). A significantly higher risk of positive allergic reaction was found in patients showing post-op allergy compatible response (ACRG), in which cases allergy tests could be recommended.

Titanium allergy in dental implant patients: a clinical study on 1500 consecutive patients.

The authors show the results obtained during the 5-year period 1973–1977 in 4600 patch tested patients in the Allergy Department of Barcelona University. The results obtained with the most common allergens (nickel sulfate, potassium dichromate, para compounds, cobalt and rubber) are studied separately. The results of testing with the allergens with a low incidence of positives are also shown. The results are compared with those published by the NACDG on 1200 patients and by Brun in Geneva on 1000 patients; 5.02 % of the tested patients showed sensitization to benzidine.

Statistical and comparative study of 4600 patients tested in Barcelona (1973-1977).

Patch tests with allergens related to cosmetics

Patch tests with the GEIDC standard series of allergens, and with 8 washers made of copper, nickel, nickel-palladium, palladium, brass, bronze, gold and iron, were carried out in 964 consecutive patients who complained of intolerance to metals and in 200 controls who did not. All subjects were also questioned as to personal and family history of atopy, occupational contact and intolerance to gold. The results provide support for the substitution of nickel in imitation jewelry with metals such as palladium or bronze.

F. Grimalt

Papers

Statistical and comparative study of 4600 patients tested in Barcelona (1973-1977).

Patch tests with allergens related to cosmetics

Contact dermatitis from nickel: an investigation of its sources

Dermatitis de contacto

Contact dermatitis by Timolol