ABSTRACT
Like fluoride, lead (Pb) accumulates on the enamel surface pre-eruptively, but it is not yet known whether it also deposits on enamel while dental caries is developing. This study evaluates Pb distribution in bovine enamel slabs submitted to a pH-cycling regimen simulating the caries process. The slabs were subjected to 8 cycles of de- and remineralizing conditions, and Pb (as acetate salt) was added to the de- and remineralized solutions at concentrations of 30 µg/l (experimental group, E1) and 300 µg/l (experimental group, E2). The control group (C) consisted of solutions to which Pb was not added. After the pH cycling, 100-µm sections of the slabs were analyzed by polarizing microscopy, to observe the extent of caries-like lesions, and these sections were used for Pb estimation by Synchrotron radiation X-ray microfluorescence. Caries lesions were observed along all superficial enamel surfaces to an extent of 120 µm. A Pb concentration gradient was observed in enamel, which decreased toward dentine. The highest Pb signals were observed for group E2, and the differences were statistically significant at enamel depths of 0 (C vs. E2; p = 0.029) and 50 µm (C vs. E2 and E1 vs. E2; p = 0.029). In conclusion, this study suggests that if Pb is present in the oral environment, it may deposit in enamel during the caries process.
Subject(s)
Dental Caries/metabolism , Dental Enamel/metabolism , Lead/pharmacokinetics , Tooth Remineralization , Animals , Cattle , Dental Caries/pathology , Dental Enamel/pathology , Dentin/metabolism , Dentin/pathology , Hydrogen-Ion Concentration , Microscopy, Polarization , Microscopy, Video , Organometallic Compounds/pharmacokinetics , Random Allocation , Spectrometry, X-Ray Emission , Temperature , Time FactorsABSTRACT
PURPOSE: In the current study we analyzed clinical evolution and therapeutic aspects of malignant diphtheric myocarditis. METHODS: Fourteen patients with primary diagnosis of diphtheria were prospectively evaluated. Cardiac involvement was detected after 11.5 (mean) days. The diagnosis of diphtheric myocarditis was done in clinical basis. RESULTS: Seven (50%) patients died. Cardiac failure was a common finding in all cases. Complete A-V block was identified in eight (57%) patients. Temporary pacemaker was implanted in 10 cases, six of them died due to myocardial failure. Definitive pacemaker was necessary in two patients with persistent complete A-V block after one-month follow-up. One patient with atrial fibrillation died with sepsis. Respiratory infection was the commonest extracardiac complication (six cases) and two patients developed Guillain-Barré syndrome. We also identified neurologic, renal and adrenal complications. CONCLUSION: Cardiac rhythm disturbances in diphtheric myocarditis are associated with high probability of necessity of temporary pacemaker and high mortality. Definitive pacemaker can be implanted in persistent complete A-V block.
Subject(s)
Diphtheria/complications , Myocarditis/etiology , Adolescent , Child , Child, Preschool , Electrocardiography , Female , Heart Block/etiology , Heart Block/therapy , Humans , Male , Myocarditis/mortality , Pacemaker, ArtificialABSTRACT
The authors call attention to the importance of Basic Cardiopulmonary Resuscitation performed by bystanders. The recommendations of the European Resuscitation Council are presented and the need to form a group for education on CPR is pointed out.