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

Anti-angiogenic and anti-proliferative activity of ziziphus leaf extract as a novel potential therapeutic agent for reducing hepatic injury in experimental hamster schistosomiasis.

BackgroundSchistosomiasis is one of the most prevalent helminthic infections worldwide. Praziquantel (PZQ) resistance poses a possible danger to the disease's ability to be controlled. Little is known about the role of Ziziphus spina-christi leaf extract (ZLE) in the treatment of hepatic schistosomiasis. However, no study has explored ZLE's anti-angiogenic and anti-proliferative activity as a possible mechanism for reducing hepatic injury in this context. Therefore, this study aimed to evaluate the therapeutic potential of ZLE as an anti-angiogenic, and anti-proliferative agent in hamsters infected with S. mansoni.MethodsFifty hamsters were used and divided into 5 groups (10 hamsters each); noninfected untreated (controls), noninfected treated with ZLE, infected untreated, infected treated with PZQ- and infected treated with ZLE. Anti-angiogenic and anti-fibrotic effects of the drugs were assessed pathologically through the immunohistochemical expression of VEGF, Ki-67, and TGF β1 in liver sections. Some oxidative stress parameters were measured in hepatic homogenates (NO, GSH, GST, and SOD), and serum liver enzymes were also assessed.ResultsA significant decrease in worm burden, granuloma size, granuloma area, and numbers in the ZLE- and PZQ-treated groups compared to the infected untreated group, and the decrease in granulomas number and tissue egg load was significantly lower in PZQ treated group compared to ZLE treated group (pConclusionOur results point to ZLE as a promising hepatoprotective therapeutic tool in the treatment of schistosome hepatic fibrosis as it has anti-angiogenic, anti-proliferative, anti-fibrotic, and antioxidant effects in hamsters infected with S. mansoni, providing scientific support for its use in conventional medicine

Immobilization of Leuconostoc-paramesenteroides Dextransucrase Enzyme and Characterization of its Enzyme Properties

Dextransucrase from Leuconostoc-paramesenteroides was immobilized using different immobilization techniques. Entrapment in calcium alginate (2%) proved to be the most suitable technique (27.6% yields). The operational stability of the immobilized was retained 100% until 11 cycle, with decreasing of 70%, of the retained activity at 13 cycles. The specific activity of the free was compared to that of the immobilized enzyme. The optimum temperature of the free enzyme was 65°C were as it was 70°C with the immobilized enzyme. The specific activity of the immobilized was higher than that of the free enzyme at pH 4. 100% of the specific activity was retained due to the thermal stability of the immobilized enzyme after heat treatment for 60 minutes at 60°C. The activation energy (EA) of the immobilized enzyme was lower than that of the free enzyme (EA= 10.3 and 12.13 Kcal/mol respectively). The calculated half-lives of the free enzyme at 40, 50, 60 and 70 were 15.0, 4.68, 4.68 and 4.0 min respectively which were lower than those of immobilized enzyme i.e. 401, 385, 295 and 42 min, respectively

Immobilization of Leuconostoc-paramesenteroides Dextransucrase Enzyme and Characterization of its Enzyme Properties

Dextransucrase from Leuconostoc-paramesenteroides was immobilized using different immobilization techniques. Entrapment in calcium alginate (2%) proved to be the most suitable technique (27.6% yields). The operational stability of the immobilized was retained 100% until 11 cycle, with decreasing of 70%, of the retained activity at 13 cycles. The specific activity of the free was compared to that of the immobilized enzyme. The optimum temperature of the free enzyme was 65°C were as it was 70°C with the immobilized enzyme. The specific activity of the immobilized was higher than that of the free enzyme at pH 4. 100% of the specific activity was retained due to the thermal stability of the immobilized enzyme after heat treatment for 60 minutes at 60°C. The activation energy (EA) of the immobilized enzyme was lower than that of the free enzyme (EA= 10.3 and 12.13 Kcal/mol respectively). The calculated half-lives of the free enzyme at 40, 50, 60 and 70 were 15.0, 4.68, 4.68 and 4.0 min respectively which were lower than those of immobilized enzyme i.e. 401, 385, 295 and 42 min, respectively

Qualitative Behavior of an Exponential Symmetric Difference Equation System

We examine the unboundedness, persistence, boundedness, uniqueness, and existence of non-negative equilibrium of an exponential symmetric difference equations system: &Omega;n+1=&alpha;1+&beta;1&Omega;n+&gamma;1&Omega;n&minus;1e&minus;(&Omega;n+&piv;n), &piv;n+1=&alpha;2+&beta;2&piv;n+&gamma;2&piv;n&minus;1e&minus;(&Omega;n+&piv;n),n=0,1,&#8943;, whereby initial values &Omega;&minus;1,&piv;&minus;1,&Omega;0,&piv;0 and parameters &alpha;1,&alpha;2 are non-negative real numbers and &beta;1,&beta;2&isin;(0,1) and &gamma;1,&gamma;2&le;0. We will discuss asymptotic global and local stability and the convergence rate of this system. Ultimately, to check our results, we set out some numerical explanations