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AIM:The 50-Hz magnetic field (MF) is a potential health-risk factor.Its effects on the cardiovascular system have not been fully investigated .This study was conducted to explore the effects of long-term exposure to 50-Hz MF on the cardiovascular system . METHODS:In the study , an exposure system was constructed and the distribution of 50-Hz MF was detected .Sixty-four Sprague-Dawley (SD) rats were exposed to 50-Hz MF at 100 μT for 24 weeks, 20 hours per day, while another 64 rats were sham exposed. During the exposure, blood pressure was measured every 4 weeks, and 24 weeks later, echocardiography, cardiac catheterisation and electrocardiography were performed .Moreover , heart and body weight were recorded , while haematoxylin-eosin staining and real-time PCR were conducted .RESULTS:The results showed that compared with the sham group , exposure to 50-Hz MF did not exert any effect on blood pressure, pulse rate, heart rate and cardiac rhythm.Further, echocardiography and cardiac catheterisation showed that there were no significant differences in the cardiac morphology and haemodynamics .In addition , histopathological examination showed that 50-Hz MF exposure had no effect on the structure of hearts .Finally, the expression of the cardiac hypertrophic relative genes did not show any significant differences between 50-Hz MF exposure group and the sham group .CONCLUSION: Taken together , in SD rats, exposure to 50-Hz/100-μT MF for 24 weeks did not show any obvious effects on the cardiovascular system .
ABSTRACT
Objective To investigate the drug resistance of patients samples in terms of pathogenic bacteria in order to provide the basis for clinical diagnosis,treatment of blood infection.Methods Six hundred and seventy-one bacteria strains out of 5042 blood samples of hospitalized patients were used to analyze its characters and drug resistance from January 2009 to December 2012 in the people's hospital of inner mongolia autonomous region.BacT AIERT 3D automatic rapid microbial detection system was applied to perform blood culture.The bacteria identification and drug sensitivity test (MIC method) were detected by using VITEK 2Compact automatic bacteria identification instrument.Results Bacteria positive rate was 13.3％ (671/5042),of which the gram negative bacilli accounted for 49.9％ (335/671),and gram positive for 40.8％ (274/671).The top 5 bacteria strains of blood samples were escherichia coli,staphylococcus,staphylococcus aureus,klebsiella pneumoniae and staphylococcus aureus.The pathogenic bacteria rates of blood samples were 30.5％(29/95),44.4％ (55/124) and 52.5％ (94/179) respectively during 2009-2012.The main source of blood bacteria renal were department of internal medicine ward (12.1％,81/671),department of general surgery (11.6％,78/671),and ICU ward (10.6％,71/671).The detected bacteria rate in department of general surgery separation rate increased to the first in 2012 from fifth in 2009.However the detected bacteria rate in department of internal medicine was down to the tenth in 2012 from the third in 2009.The drug resistance rate of imipenem,piperacillin/tazobactam,cefotaxime,ceftazidime resistant cefotetan on escherichia coli and klebsiella pneumoniae were all less than 9.7％,and the rate of linezolid,vancomycin,teicoplanin,quinupristin/dafoe leptin and nitrofurantoin resistance of staphylococcus aureus,staphylococcus bacteria and gold staphylococcus aureus were all less than 2.3％.Conclusion The distribution,sources and drug resistance of pathogenic bacteria had been changed recently.Therefore the laboratory shall strengthen the monitoring of drug resistance of bacteria in the bloodstream infection in order to guide clinical rational application of antibiotics.