Alterations in Adenylate Kinase Activity in Human PBMCs after In Vitro Exposure to Electromagnetic Field: Comparison between Extremely Low Frequency Electromagnetic Field (ELF) and Therapeutic Application of a Musically Modulated Electromagnetic Field (TAMMEF)

This study investigated the effects of electromagnetic fields on enzymes involved in purine metabolism in human peripheral blood mononuclear cells in vitro. Cells were obtained from 20 volunteers. We tested both low-energy, extremely low frequency (ELF; 100-Hz) electromagnetic fields and the Therapeutic Application of Musically Modulated Electromagnetic Fields (TAMMEFs); the latter is characterized by variable frequencies, intensities, and wave shapes. Adenylate kinase activity was increased after ELF field exposure but decreased slightly after TAMMEF exposure. Neither of the two electromagnetic field affected the activities of the purine metabolism enzymes ecto-5′-nucleotidase, adenosine deaminase, and adenosine kinase. We concluded that ELF fields may influence cellular electrical charge stability; stimulation of adenylate kinase activity could restore the cell to a state of equilibrium. In contrast, TAMMEF fields may be useful for maintaining and regulating the cellular electrical charge

Critical Appraisal of the MTT Assay in the Presence of Rottlerin and Uncouplers

<p>Abstract</p> <p>Rottlerin is a natural product isolated from <it>Mallotus philippinensis</it>. This polyphenolic compound, originally described as a selective inhibitor of PKC&#948;, can inhibit many other PKC-unrelated kinases and has a number of biological actions, including mitochondrial uncoupling effects. We recently found that Rottlerin inhibits the transcription factor nuclear factor &#954;B in different cell types, causing downregulation of cyclin D1 and growth arrest. The present study was carried out to clarify the surprising lack of effect of Rottlerin on MCF-7 cell viability, assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test. We found that Rottlerin causes overestimation of the MTT test, leading to inconsistent results between cell number and cell viability. Rottlerin, however, strongly differs from other antioxidant polyphenols, which directly reduce tetrazolium salts, since it does not exhibit any reactivity toward the tetrazolium salts in vitro nor does it modulate lactate dehydrogenase activity. The interference in the MTT assay occurred only in cultured cells, concomitantly with a decrease in the energy charge. Because the same MTT overestimation was observed in the presence of uncoupling agents, we conclude that the Rottlerin artifact is linked to its uncoupling action that, by accelerating oxidative chain, accidentally results in enhanced MTT reduction. These results suggest caution in the use of the MTT assay in the presence of Rottlerin and uncouplers in general.</p

Critical Appraisal of the MTT Assay in the Presence of Rottlerin and Uncouplers

Abstract Rottlerin is a natural product isolated from Mallotus philippinensis. This polyphenolic compound, originally described as a selective inhibitor of PKCδ, can inhibit many other PKC-unrelated kinases and has a number of biological actions, including mitochondrial uncoupling effects. We recently found that Rottlerin inhibits the transcription factor nuclear factor κB in different cell types, causing downregulation of cyclin D1 and growth arrest. The present study was carried out to clarify the surprising lack of effect of Rottlerin on MCF-7 cell viability, assessed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test. We found that Rottlerin causes overestimation of the MTT test, leading to inconsistent results between cell number and cell viability. Rottlerin, however, strongly differs from other antioxidant polyphenols, which directly reduce tetrazolium salts, since it does not exhibit any reactivity toward the tetrazolium salts in vitro nor does it modulate lactate dehydrogenase activity. The interference in the MTT assay occurred only in cultured cells, concomitantly with a decrease in the energy charge. Because the same MTT overestimation was observed in the presence of uncoupling agents, we conclude that the Rottlerin artifact is linked to its uncoupling action that, by accelerating oxidative chain, accidentally results in enhanced MTT reduction. These results suggest caution in the use of the MTT assay in the presence of Rottlerin and uncouplers in general.</p

NUOVI MARKERS DI DANNO MIOCARDICO: DOLORE TORACICO E COPEPTINA

ABSTRACT Chest pain is one of the most common cause for Emergency Department (ED) visits. Nowadays the diagnostic gold standard for acute myocardial infarction (AMI) is Troponin T but its delayed release reduces the diagnostic sensibility in the early ischemic time. Copeptin, a biomarker associated with endovascular stress regulation, has been studied in various cardiovascular events. The aim of this study is to analyse the diagnostic/prognostic value of copeptin in myocardial infarction patients admitted to ED for chest pain to obtain a careful rule out of AMI. 90 consecutive patients admitted for chest pain were studied. Inclusions criteria were Chest Pain Score > 4 and negative electrocardiography for acute coronary syndrome (ACS) according to the European Society of Cardiology Guidelines 2009. Copeptin was evaluated at the ED presentation. 50 patients were discharged after AMI exclusion with negative copeptin and troponin. 40 patients were admitted, 18 of them had myocardial infarction, 12 had positive copeptin with negative troponin and myoglobin values. The overall copeptin sensibility in the infarcted patients was 69,4%, increasing to 77,7% adding troponin T, with a negative predictive value of 78%. Upon multiple regression frame copeptin appears to be an independent predictor factor of number of vessels involved in ACS (p<0,006). Copeptin blood level risen early in infarcted patients has a good sensibility; the combination with troponin T improved the diagnostic performance of these two biomarkers in AMI patients. Copeptin could be used also as a prognostic factor of myocardial damage because of its correlation with coronary involvement