Cardiotoxicity of Freon among refrigeration services workers: comparative cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Freon includes a number of gaseous, colorless chlorofluorocarbons. Although freon is generally considered to be a fluorocarbon of relatively low toxicity; significantly detrimental effects may occur upon over exposure. The purpose of the present study is to investigate whether occupational exposure to fluorocarbons can induce arterial hypertension, myocardial ischemia, cardiac arrhythmias, elevated levels of plasma lipids and renal dysfunction.</p> <p>Methods</p> <p>This comparative cross-sectional study was conducted at the cardiology clinic of the Suez Canal Authority Hospital (Egypt). The study included 23 apparently healthy male workers at the refrigeration services workshop who were exposed to fluorocarbons (FC 12 and FC 22) and 23 likewise apparently healthy male workers (unexposed), the control group. All the participants were interviewed using a pre-composed questionnaire and were subjected to a clinical examination and relevant laboratory investigations.</p> <p>Results</p> <p>There were no significant statistical differences between the groups studied regarding symptoms suggesting arterial hypertension and renal affection, although a significantly higher percentage of the studied refrigeration services workers had symptoms of arrhythmias. None of the workers had symptoms suggesting coronary artery disease. Clinical examination revealed that the refrigeration services workers had a significantly higher mean pulse rate compared to the controls, though no significant statistical differences were found in arterial blood pressure measurements between the two study groups. Exercise stress testing of the workers studied revealed normal heart reaction to the increased need for oxygen, while sinus tachycardia was detected in all the participants. The results of Holter monitoring revealed significant differences within subject and group regarding the number of abnormal beats detected throughout the day of monitoring (p < 0.001). There were no significant differences detected in the average heart rate during the monitoring period within subject or group. Most laboratory investigations revealed absence of significant statistical differences for lipid profile markers, serum electrolyte levels and glomerular lesion markers between the groups except for cholesterol and urinary β2-microglobulin (tubular lesion markers) levels which were significantly elevated in freon exposed workers.</p> <p>Conclusions</p> <p>Unprotected occupational exposure to chlorofluorocarbons can induce cardiotoxicity in the form of cardiac arrhythmias. The role of chlorofluorocarbons in inducing arterial hypertension and coronary artery diseases is unclear, although significantly elevated serum cholesterol and urinary β2-microglobulin levels raise a concern.</p

Association of single nucleotide polymorphisms in the genes <it>ATM</it>, <it>GSTP1</it>, <it>SOD2</it>, <it>TGFB1</it>, <it>XPD</it> and <it>XRCC1</it> with risk of severe erythema after breast conserving radiotherapy

<p>Abstract</p> <p>Purpose</p> <p>To examine the association of polymorphisms in <it>ATM</it> (codon 158), <it>GSTP1</it> (codon 105), <it>SOD2</it> (codon 16), <it>TGFB1</it> (position −509), <it>XPD</it> (codon 751), and <it>XRCC1</it> (codon 399) with the risk of severe erythema after breast conserving radiotherapy.</p> <p>Methods and materials</p> <p>Retrospective analysis of 83 breast cancer patients treated with breast conserving radiotherapy. A total dose of 50.4 Gy was administered, applying 1.8 Gy/fraction within 42 days. Erythema was evaluated according to the Radiation Therapy Oncology Group (RTOG) score. DNA was extracted from blood samples and polymorphisms were determined using either the Polymerase Chain Reaction based Restriction-Fragment-Length-Polymorphism (PCR-RFL) technique or Matrix-Assisted-Laser-Desorption/Ionization –Time-Of-Flight-Mass-Spectrometry (MALDI-TOF). Relative excess heterozygosity (REH) was investigated to check compatibility of genotype frequencies with Hardy-Weinberg equilibrium (HWE). In addition, p-values from the standard exact HWE lack of fit test were calculated using 100,000 permutations. HWE analyses were performed using R.</p> <p>Results</p> <p>Fifty-six percent (46/83) of all patients developed erythema of grade 2 or 3, with this risk being higher for patients with large breast volume (odds ratio, OR = 2.55, 95% confidence interval, CI: 1.03–6.31, p = 0.041). No significant association between SNPs and risk of erythema was found when all patients were considered. However, in patients with small breast volume the <it>TGFB1</it> SNP was associated with erythema (p = 0.028), whereas the SNP in <it>XPD</it> showed an association in patients with large breast volume (p = 0.046). A risk score based on all risk alleles was neither significant in all patients nor in patients with small or large breast volume. Risk alleles of most SNPs were different compared to a previously identified risk profile for fibrosis.</p> <p>Conclusions</p> <p>The genetic risk profile for erythema appears to be different for patients with small and larger breast volume. This risk profile seems to be specific for erythema as compared to a risk profile for fibrosis.</p

Nanotechnology and Drug Delivery

Nowadays nanotechnology represents an expanding field that is providing powerfultools for the pharmaceutical industry such as polymeric, solid lipid, metallic, and magnetic NPs, liposomes, dendrimers, and other nanostructures. The development of nanopharmaceutics allows the understanding of some of the major mechanisms of current diseases on a molecular basis. Particularly, drug delivery mediated by nanosystems is relevant since NPs are able to reach the target organ and deliver the drug with a desirable profile according to the pathology needs, minimizing undesirable side effects. The main physicochemical properties of nanosystems are related with the increase in the surface-to-volume ratio of the particles, their permeability across biological barriers, and the surface modification of nanodevices. These parameters are relevant in drug loading and release and particularly for the targeted delivery to cells showing specific markers or receptors in the membrane surface.Fil: Islan, German Abel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; ArgentinaFil: Martin Saldaña, Sergio. Gihon Laboratorios Químicos SRL; ArgentinaFil: Chevalier, Merari Tumin. Gihon Laboratorios Químicos SRL; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Castro, Guillermo Raul. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Fermentaciones Industriales. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Fermentaciones Industriales; Argentin