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Journal Article 2006; 27(Suppl 2): 9-13 PubMed PMID: 17159769 Citation  Keywords:  Adolescent, Adult, Aged, Aniline Compounds:metabolism, Animals, Anisoles:pharmacokinetics, Carcinogens:pharmacokinetics, Child, Child, Preschool, Cytochrome P-450 Enzyme System:metabolism, Female, Humans, In Vitro Techniques, Male, Metabolic Detoxication,.   

OBJECTIVES: The detoxifying metabolism of a potent rodent carcinogen, 2-nitroanisole (2-NA) by human, rabbit and rat cytochromes P450 (P450) was investigated. Comparison between P450s of experimental animals and humans is essential for the extrapolation of animal carcinogenicity data to the human situation and to assess health risk.

METHODS: HPLC with UV detection was employed for the separation and characterization of 2-NA metabolites formed by hepatic microsomes, human recombinant P450s and purified rat and rabbit P450s.

RESULTS: An O-demethylated metabolite of 2-NA, 2-nitrophenol (2-NP), and two oxidation products of this metabolite [2,5-dihydroxynitrobenzene (2,5-DNB) and 2,6-dihydroxynitrobenzene (2,6-DNB)] were generated by microsomes and P450s from the species investigated, but at different levels. All the metabolites are detoxication products. 2-NP is the major metabolite generated by rabbit and rat microsomes, but 2,5-DNB is the predominant product in human microsomes. Using human recombinant P450s and purified rodent P450s, we found that human P450 2E1, 1A1 and 2B6 as well as orthologous animal P450s were the most efficient enzymes oxidizing 2-NA to 2-NP, while P450 2E1 and 1A1 were the most effective in the formation of 2,5-DNB and 2,6-DNB. In human hepatic microsomes, 2-NA was oxidized mainly by P4502E1. 2-NA and its reductive metabolite o-anisidine induced rat hepatic and renal P450 1A1/2 and NAD(P)H:quinone oxidoreductase (NQO1), thus modifying their own detoxication and/or activation pathways.

CONCLUSIONS: The data demonstrated the participation of orthologous P450s in 2-NA oxidation by all species and indicated that the rat and rabbit might serve as suitable models to mimic 2-NA oxidation in man....

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Journal Article 2006; 27(Suppl 1): 61-68 PubMed PMID: 16892010 Citation  Keywords:  Adult, Aged, Chronic Disease, Corrosion, Dental Alloys:adverse effects, Electron Probe Microanalysis, Female, Gingiva:drug effects, Humans, Hypersensitivity:etiology, Lymphocyte Activation, Male, Metals:adverse effects, Middle Aged, Mouth Mucosa:drug effe.   

OBJECTIVE: Corrosion products of different metallic alloys used in prosthetic dentistry often cause the development of a bluish-grey pigmentation of gingiva and oral mucosa. The aim of this study was to determine the content of metals in metallic pigmentations and evaluate the immune response to metals found in the oral cavity.

MATERIAL AND METHODS: The local tissue reactions were investigated clinically by electron microscopy and by energy dispersive x-ray microanalysis. An extensive anamnesis of the patients was recorded as well as earlier contacts with health care institutions. The immunological response to metallic components of dental alloys was evaluated in 34 patients by MELISA, a modified test for lymphocyte proliferation. In addition, cytokines in culture media were determined in 10 persons by the Human Inflammation Antibody Array.

RESULTS: Dense particles containing metals were found in the matrix among collagen fibrils and in close proximity of the lamina basalis of the gingival epithelium. Particles were also localized intracellularly in fibroblasts, macrophages, and endothelial cells. Metallic depositions consisted predominantly of silver accompanied by selenium and sulphur. Twenty five out of 34 patients revealed high lymphocyte reactivity (positive MELISA test) to one or more metal components of dental restorations. A correlation between the positivity in MELISA test and number of dental alloys in the oral cavity was also found. Twenty MELISA positive patients suffered from serious health problems (various allergies, autoimmune diseases, Parkinson's syndrome etc.). Nickel and inorganic mercury were the most common sensitizers in vitro. The cytokine assay revealed that mercury chloride activated predominantly TH2 lymphocytes, while nickel chloride activated mainly TH1 lymphocytes.

CONCLUSIONS: Metallic pigmentations in the oral cavity demonstrate a corrosion process and may pose a risk in immunologically susceptible patients....

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Clinical Trial 2006; 27(Suppl 1): 69-72 PubMed PMID: 16892009 Citation  Keywords:  Dental Implantation, Endosseous, Dental Implants:adverse effects, Humans, Hypersensitivity:prevention & control, Materials Testing, Treatment Outcome, Zirconium,.   

: Titanium dental implants have been used successfully in implantology for more than 40 years. Recent research, however, suggests that titanium might have more side effects than previously believed. Zirconia ceramics have been employed in orthopaedic surgery for approximately 30 years and were recently introduced into dentistry as a metal replacement for crown and bridge work as well as implant abutments. Zirconium dioxide has been shown in both in vitro and in vivo studies to have desirable osseointegrative properties. This clinical study shows that dental implants made from zirconia are a feasible alternative to titanium dental implants. In addition to excellent cosmetic results, zirconia implants allow a degree of osseointegration and soft tissue response that is superior to titanium dental implants....

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Clinical Trial 2006; 27(6): 822-827 PubMed PMID: 16892007 Citation  Keywords:  Adult, Copper:blood, Exercise:physiology, Humans, Male, Oxygen Consumption:physiology, Reference Values, Running:physiology, Zinc:blood,.   

: This study was carried out to investigate the effects of 6-week aerobic exercise program upon blood Zn and Cu levels. There were 12 male university students with an average age of 21.67+/-0.89 years and no regular training habits participated in the study. The participants were subjected three days a week 1 hour a day continuous running program on treadmill with an intensity of 60-70% for a period of six weeks. They were fed with zinc and copper free diet throughout the study and it was made sure that they were not using copper or zinc containing vitamin tablets. The difference between the pre and post study period were found to be statistically significant as regards to both resting and maximal loading conditions (p<0.01). The pre and post training maxVO2 values were also found to be positively correlated with the copper and zinc levels in blood. Both the copper and zinc blood levels were found decreased after the training period p<0.05....

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Journal Article 2006; 27(Suppl 1): 41-45 PubMed PMID: 16804516 Citation  Keywords:  Adult, Antibodies, Bacterial:analysis, Case-Control Studies, Female, Helicobacter Infections:complications, Helicobacter pylori:immunology, Humans, Immunoglobulin A:analysis, Male, Middle Aged, Thyroiditis, Autoimmune:immunology,.   

OBJECTIVES: In this study we examined the anti-Helicobacter pylori (anti-H. pylori) antibodies in patients with autoimmune thyroiditis, with and without different polyglandular involvement, and in healthy controls.

MATERIAL & METHODS: Patients with autoimmune thyroiditis (AT) were divided into three groups: Group A: 23 patients with isolated AT, Group B: 30 patients with AT as a part of polyglandular activation of autoimmunity, and Group C: 7 patients with AT as a part of autoimmune polyglandular syndrome type II. Thirty healthy individuals served as controls (Group D). Anti-H. pylori antibodies were determined first by ELISA for classes IgG, IgA, and IgM, and subsequently by immunoblot for classes IgG and IgA.

RESULTS: ELISA: The number of patients with IgA antibodies in Group A (39%) and Group B (30%) differed significantly from controls (7%, p<0.05). Immunoblot: Anti-CagA antibodies were found in 13% of patients in Group A, 7% of Group B, 0% of Group C, and 20% of Group D. A higher seroprevalence, as compared to controls, was found for IgG to the VacA (p=0.01), 30 kDa (p=0.001), and 17 kDa (p=0.008) antigens in Group A and for IgG to the 30 kDa antigen in Group C (p=0.037). A significantly higher seroprevalence, as compared to controls, was likewise found for IgA to the 17 kDa antigen in Group A (p=0.015).

CONCLUSIONS: A different distribution of antibodies to H. pylori antigens was found in patients with isolated AT compared to patients with AT coupled with a polyglandular syndrome....

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Journal Article 2006; 27(Suppl 1): 36-39 PubMed PMID: 16804515 Citation  Keywords:  Biopsy, Breast Neoplasms:chemistry, Case-Control Studies, Female, Humans, Metals:pharmacokinetics,.   

OBJECTIVES: High levels of transition metals such as iron, nickel, chromium, copper, and lead are closely related to free radical generation, lipid peroxidation, formation of DNA strand breaks, and tumor growth in cellular systems. In order to determine the correlation to malignant growth in humans, we investigated the accumulation of heavy metals in 20 breast cancer biopsies and compared the findings to the levels found in 8 healthy biopsies.

METHODS: The concentration of transition metals in breast cancer and control biopsies was assessed by a standardized Atomic Absorption Spectrofotometry technique with acidic hydrolysis for sample preparation. Additionally, heavy metal analysis in control biopsies was also performed with an Inductive Coupled Plasma--Mass Spectroscopy technique. For statistical analysis of the results, the Mann-Whitney U Test was applied.

RESULTS: A highly significant accumulation of iron (p<0.0001), nickel (p<0.00005), chromium (p<0.00005), zinc (p<0.00001), cadmium (p<0.005), mercury (p<0.005), and lead (p< 0.05) was found in the cancer samples when compared to the control group. Copper and silver showed no significant differences to the control group, whereas tin, gold, and palladium were not detectable in any biopsies.

CONCLUSIONS: The data suggest that pathological accumulation of transition metals in breast tissue may be closely related to the malignant growth process....

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Clinical Trial 2006; 27(Suppl 1): 53-58 PubMed PMID: 16804514 Citation  Keywords:  Dental Amalgam:adverse effects, Electrodiagnosis:methods, Electrogalvanism, Intraoral, Female, Humans, Hypersensitivity:complications, Male, Metals:adverse effects, Middle Aged, Pain:etiology, Saliva:chemistry,.   

OBJECTIVE OF THE STUDY: The occurrence of galvanism with its heterogeneous symptomatology is often the source of considerable problems. Abrasion and corrosion not only damage dental alloys but also burden the organism by release of metallic particles. The objective of this study is to evaluate the hypothesis that measurement of galvanic currents could be a useful diagnostic method. PATIENT GROUPS AND METHODOLOGY: Three hundred fifty-seven persons with dental metal restorations were divided into groups according to abnormal values of galvanic currents and by oral discomfort. In all persons a detailed examination of the oral cavity was performed, and galvanic currents were measured. In one hundred fifty-nine patients abnormal galvanic currents were found. Measurement of metallic elements in saliva was performed in these patients and in a group of 21 healthy volunteers without any metals in the oral cavity. Thirty-three patients agreed to treatment which involved removal of the causative alloys and their replacement by non-metallic restorations.

RESULTS: No correlation was found between the values of measured currents and the number of teeth treated by metal restorations. However, patients with metal restorations had significantly higher contents not only of mercury, but also of tin, silver, copper, and gold in the saliva than patients without metallic restorations. After removal of the electro-active restorations, both the contents of metals in saliva and galvanic currents decreased in comparison with the levels before the treatment.

CONCLUSIONS: Galvanic effects as well as metal particles may induce a series of local or systemic pathological phenomena in sensitive individuals. The occurrence of pathologically acting galvanic effects is influenced not only by the composition and combination of different dental alloys, but to a significant degree also by the quality of used materials and processing....

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Case Reports 2006; 27(Suppl 1): 49-52 PubMed PMID: 16804513 Citation  Keywords:  Dental Restoration, Permanent:adverse effects, Female, Humans, Hypersensitivity:diagnosis, Metals:adverse effects, Middle Aged, Nickel:adverse effects, Patch Tests,.   

: In dentistry, a variety of potentially allergenic metals are used, such as mercury, palladium, nickel, gold, chromium, cobalt and other metals. This paper describes a diagnostic approach from a dentist's point of view, which enables analysis of metals in a patient's oral cavity. If metal allergy is suspected, a micro analysis can be used to determine which metals are present in the restorations. When the exact composition of the dental materials is known, the patient can be tested in vivo (patch test) and/or in vitro (lymphocyte proliferation test) to reveal sensitization. Two patients with nickel allergy are described where removal of nickel-containing materials (bridge and orthodontic wire) resulted in the marked alleviation of symptoms and improvement of health. Finally, if allergy to specific metals has been established, the restorations containing the implicated metals should be removed to discontinue the exposure and thus facilitate the patient's health....

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