metallothionein and Foreign-Body-Reaction

Despite studies concerning toxic reactions related to amalgam components in the literature, few studies have been devoted to evaluate local noxious effects of amalgam tattoos (AT) on biological tissues. In addition, little is known about activation of inflammatory cells by mucosa-implanted amalgam debris. Tissue reaction to AT depends on the particle size. Human leukocyte antigen DR (HLA-DR) is an activation marker of inflammatory cells associated with antigen presentation. Metallothioneins (MT) are proteins involved with metal detoxication, including mercury and silver. The purpose of the present study was to investigate the immunolocalization of HLA-DR and MT in AT with large or powdered particles. Paraffin-embedded AT tissue blocks were sectioned and subjected to immunohistochemistry for HLA-DR and MT localization. The results demonstrated a dense mononuclear inflammatory infiltrate associated with large and powdered debris and positivity for HLA-DR and MT in inflammatory cells. While blood vessel walls and connective fibers impregnated with powdered particles were negative for HLA-DR, they were positive for MT. In addition, wherever epithelial basement membrane impregnation by powdered amalgam particles was observed, a strong positivity for MT was detected. These findings demonstrate that residual elements of AT still have noxious local effects over tissues.

Topics: Argyria; Dental Amalgam; Foreign-Body Reaction; HLA-DR Antigens; Humans; Immunoenzyme Techniques; Leukocytes, Mononuclear; Metallothionein; Mouth Mucosa; Particle Size; Pigmentation Disorders

We examined the distribution of metallothionein (MT), a stress-inducible protein, and the cardiomyocyte diameter in human hearts after left-ventricular assist device (LVAD) support.. Remodeling in end-stage heart failure is characterized by myocyte hypertrophy and alterations of several inducible proteins. LVADs used as a bridge to cardiac transplantation unload the left ventricle and may lead to a reversal of the remodeling, but little is known about the pathophysiology of this process.. The immunoreactivity for MT and the cardiomyocyte diameter was analyzed in left-ventricular tissue specimens of 17 patients with end-stage heart failure before and after LVAD support.. MT positive cells were mainly located sub-endocardially in vacuolized cardiomyocytes and in small vessels throughout the myocardium. During LVAD support, MT-positive myocytes decreased in the sub-endocardial (p < 0.008) and sub-epicardial region (p < 0.003), MT-positive vessels decreased similarly (p < 0.003). Cardiomyocyte diameter decreased significantly only in the sub-endocardium (p < 0.03). Hearts of patients supported longer than 88 days (= median) showed substantially lower MT reactivity at the time of LVAD explantation as compared to patients supported less than 88 days.. Our results suggest that unloading of the left ventricle during prolonged LVAD support leads to regression of cellular hypertrophy and a decrease of MT expression. The preferential reduction of MT-positive vacuolized cardiomyocytes in the sub-endocardium is comparable with the concept of greatest reduction of wall stress in this area of the myocardium and may be due to the improvement of myocardial blood flow and the energy balance.

Topics: Adult; Antibodies, Monoclonal; Biomarkers; Cell Size; Foreign-Body Reaction; Heart Failure; Heart-Assist Devices; Humans; Metallothionein; Middle Aged; Myocardium; Severity of Illness Index; Ventricular Remodeling