Maria Christakis-Hampsas

Conversion of atrial fibrillation to sinus rhythm using acute intravenous procainamide infusion.

The efficacy and safety of intravenous procainamide in the conversion of atrial fibrillation was investigated. A total of 114 patients without severe heart failure were randomized to receive either intravenous procainamide (1 g over 30 minutes, followed by an infusion of 2 mg/min over 1 hour) or placebo in a double-blind trial. Digoxin (0.5 mg intravenously) was administered to all patients who had not previously been receiving digoxin. Treatment was considered successful if sinus rhythm was restored within 1 hour after starting the infusion. Conversion to sinus rhythm was achieved in 29 (50.9%) of the 57 patients treated with procainamide and in 16 (28.1%) of the 57 who received placebo (P ≊ 0.012). When the duration of the atrial fibrillation was ≤48 hours, conversion to sinus rhythm was achieved in 29 (69%) of the 42 patients receiving procainamide and in 16 (38.1%) of those receiving placebo (P ≊ 0.004). None of the patients with atrial fibrillation lasting ≤48 hours converted to sinus rhythm in either group. Another factor that played a role in the restoration of sinus rhythm was the size of the left atrium: the smaller the left atrium, the larger the success rate. The results of the study suggest that intravenous procainamide is an effective and safe means for the rapid termination of atrial fibrillation of recent onset and that its success rate is inversely related to the size of the left atrium. However, the drug is ineffective in the conversion of atrial fibrillation lasting more than 48 hours.

The increasing significance of biomonitoring for pesticides and organic pollutants

Toxicology is defined as the study of the adverse effects of chemcals to human and animal organisms. In toxicology research, the ignificance of dose is well understood, yet the relevance of expoure in human studies (and the risk assessment) is not always ufficiently defined. In the field of regulatory toxicology exposure ata for establishing exposure limit values are required. Toxicology s considered to be a science and an art. It is considered a science n the context of setting up methods to assess the concentration of hemicals either in the air or in the body fluid samples, while it is lso an art during the estimation of exposure to chemicals for which lso exposure time, duration and frequency have to be known. EU egulations demand proper exposure assessment with biomonitorng if necessary. Therefore, scientists have developed sophisticated iomonitoring methods for hundreds of chemicals while instrucions for accurate and precise sampling are given to occupational ealth professionals. Despite all these efforts biomonitoring is clasified as a routine procedures only in few countries in Europe, Asia nd America. It is highly important not only to prove that workrs and consumers are not exposed but also to show that chemical ompounds are not accumulating in the body or seriously affecting ny body functions. The current issue includes topics that cover key areas of ongong development: rapid and sensitive methods for Biomonitoring f Xenobiotics, separation and identification of compounds, gene xpression and structure analysis and risk assessment. In addition, he issue provides important knowledge to the readers, in terms of heoretical aspects and practical considerations. Various methodlogical challenges used for analytical techniques of molecular tructure identification, solid phase assays, receptor-mediated toxcity and finally risk assessment are presented. An important goal of his issue is to bring together scientists from toxicology, chemistry, iochemistry, life sciences and cell and molecular biology on an mportant and rapidly developing scientific field of biomonitoring or pesticides and organic pollutants. The objective of this issue is o provide the readers with an understanding of the new technolgy used for unraveling molecular structure and function and its pplications in the field of Biomonitoring of Xenobiotics and risk ssessment. Principles and applications of biomonitoring for pesticide and nvironmental pollutants and for low level long-term exposure are resented and methodological problems related to biomonitoring tudies are discussed in this issue. Pesticides have an impact on uman health after exposure at very low doses from environmental rigin or food supply. However the adverse health effects of mixures of pesticides are still not known. Additive effects are possible ith some pesticides, although not all mixtures of similar pesticides