Electrocardiographic changes following experimental hypokalemia in sheep

Hypokalemia in sheep causes cardiac arrhythmia and electrocardiographic changes such as changing the shape of QRS,complex and T wave and the distance between waves. In this study, 20 rams with the age of 12-15 months were divided into two groups. Electrocardiography was used to check the heart rhythm. After recording ECG and sampling, in order to create hypokalemia Isoflupredon acetat at a dose of 4mg was used intramuscularly in oll 10 treatment. All P waves in the control and the experimental group was recorded as positive and their monophasic or diphasic state was also studied. Between days 0 to 4, 30 cases of monophasic and 20 cases of diphasic P wave was recorded is the control group. In the treatment group, these figures were 21 and 29 cases respectively. Different shapes of QRS waves were seen  in both treatment groups .In the control group they were recorded as QRS in 10 cases, qrs in 15 cases and qRs in 25 cases with in the treatment  group it was QRS in 31 cases, Qrs in 1 case, qrs in 4 cases and qRs in 14 cases. By examining the ECG in the control group on days zero to 4th day, sinus arrhythmia and atrioventricular block was observed in 7 and 2 cases respectively and in the treatment group sinus arrhythmia, atrioventricular block, atrial premature contraction and sinus tachycardia was recorded in 14, 12, 3 and 5 cases respectively. The results indicated that various arrhythmias can be observed due to hypokalemia. As physiologic arrhythmias can lead to pathologic arrhythmias, the animals should be treated with anti-arrhythmia drugs

Effect of Superparamagnetic Iron Oxide Nanoparticles-Labeling on Mouse Embryonic Stem Cells

Objective: Superparamagnetic iron oxide nanoparticles (SPIONs) have been used to label mammalian cells and to monitor their fate in vivo using magnetic resonance imaging (MRI). However, the effectiveness of phenotype of labeled cells by SPIONs is still a matter of question. The aim of this study was to investigate the efficiency and biological effects of labeled mouse embryonic stem cells (mESCs) using ferumoxide- protamine sulfate complex. Materials and Methods: In an experimental study, undifferentiated mESCs, C571 line, a generous gift of Stem Cell Technology Company, were cultured on gelatin-coated flasks. The proliferation and viability of SPION-labeled cells were compared with control. ESCs and embryoid bodies (EBs) derived from differentiated hematopoietic stem cells (HSCs) were analyzed for stage-specific cell surface markers using fluorescence-activated cell sorting (FACS). Results: Our observations showed that SPIONs have no effect on the self-renewal ability of mESCs. Reverse microscopic observations and prussian blue staining revealed 100% of cells were labeled with iron particles. SPION-labeled mESCs did not significantly alter cell viability and proliferation activity. Furthermore, labeling did not alter expression of representative surface phenotypic markers such as stage-specific embryonic antigen 1 (SSEA1) and cluster of differentiation 117 (CD117) on undifferentiated ESC and CD34, CD38 on HSCs, as measured by flowcytometry. Conclusion: According to the results of the present study, SPIONs-labeling method as MRI agents in mESCs has no negative effects on growth, morphology, viability, proliferation and differentiation that can be monitored in vivo, noninvasively. Noninvasive cell tracking methods are considered as new perspectives in cell therapy for clinical use an