Mitral Regurgitation after Percutaneous Balloon Mitral Valvotomy in Patients with Rheumatic Mitral Stenosis: A Single-Center Study

Background: Percutaneous balloon mitral valvotomy (BMV) is the gold standard treatment for rheumatic mitral stenosis (MS) in that it causes significant changes in mitral valve area (MVA) and improves leaflet mobility. Development of or increase in mitral regurgitation (MR) is common after BMV. This study evaluated MR severity and its changes after BMV in Iranian patients. Methods: We prospectively evaluated consecutive patients with severe rheumatic MS undergoing BMV using the Inoue balloon technique between February 2010 and January 2013 in Madani Heart Center, Tabriz, Iran. New York Heart Association (NYHA) functional class and echocardiographic and catheterization data, including MVA, mitral valve mean and peak gradient (MVPG and MVMG), left atrial (LA) pressure, pulmonary artery systolic pressure (PAPs), and MR severity before and after BMV, were evaluated. Results: Totally, 105 patients (80% female) at a mean age of 45.81 ± 13.37 years were enrolled. NYHA class was significantly improved after BMV: 55.2% of the patients were in NYHA functional class III before BMV compared to 36.2% after the procedure (p value < 0.001). MVA significantly increased (mean area = 0.64 ± 0.29 cm2 before BMV vs. 1.90 ± 0.22 cm2 after BMV; p value < 0.001) and PAPs, LA pressure, MVPG, and MVMG significantly decreased. MR severity did not change in 82 (78.1%) patients, but it increased in 18 (17.1%) and decreased in 5 (4.8%) patients. Patients with increased MR had a significantly higher calcification score (2.03 ± 0.53 vs.1.50 ± 0.51; p value < 0.001) and lower MVA before BMV (0.81± 0.23 vs.0.94 ± 0.18; p value = 0.010). There were no major complications. Conclusion: In our study, BMV had excellent immediate hemodynamic and clinical results inasmuch as MR severity increased only in some patients and, interestingly, decreased in a few. Our results, underscore BMV efficacy in severe MS. The echocardiographic calcification score was useful for identifying patients likely to have MR development or MR increase after BMV

Evaluation of Absorbed Dose of Critical Organ in Rando Phantom under Head, Abdomen and Pelvis Spiral CT Scan by Thermo Luminescent Dosimetery - TLD

Background & Objectives: Computed tomography (CT) represents 11% of all diagnostic radiology procedures but it contributes to almost 67% of the total effective dose to the human population. In head and neck CT which consist of 1/3 of total CT scans, other critical organs such as lenses and thyroid are in the radiation field. Also in the abdomen and pelvis scan, irradiation of ovaries is unavoidable. Because of high sensitivity of these organs, the probability of abnormality and cancer in these organs has increased. Therefore the dose assessment in these organs is very important. The aim of this study is to estimate the absorbed dose in critical organ of patient undergoing common head, neck, abdomen and pelvic spiral CT scan. Materials & Methods: In this study, Lithium fluoride thermo luminescent dosimeters (TLD-100, Harshaw) were used to determine the absorbed dose of critical organ of tissue equivalent rando phantom (Alderson research industries, Inc, Stanford, Conn, U.S.A). The phantom was sectional in design and manufactured with a 2.5 cm slab thickness. Each section contained some holes that allowed accommodation of TLDs. At least two crystals were placed in each hole. The average value of the TLD readings was taken as the organ dose. Readouts were obtained on a Harshaw 4500 reader (Harshaw, Ohio, USA). For calibration, the annealed dosimeters were exposed to an X-ray beam resulting from 120 kVp tube voltage and calibration curve was plotted. Results: result of this study showed during head CT scan the maximum absorbed dose belongs to occipital bones skin. Which were about 11.45 mGy and the minimum absorbed dose belong to thyroid gland which was 0.5 mGy. During abdomen & pelvic spiral CT, the maximum absorbed dose of abdomen skin was 23.32 mGy and the minimum absorbed dose in the eye region was 0.15 mGy. The readout results are correlated with the results of spiral CT detector with the “ALARA” principle, we recommend suitable techniques should be selected to reduce absorbed dose of critical organ without reducing image quality. Conclusion: further research is required to investigate whether modification of the parameters used during routine spiral CT scan can be limited absorbed dose of critical organ without a significant loss of image quality

Effects of Extremely Low-Frequency Electromagnetic Fields on Neurogenesis and Cognitive Behavior in an Experimental Model of Hippocampal Injury

Exposure to extremely low-frequency electromagnetic fields may induce constant modulation in neuronal plasticity. In recent years, tremendous efforts have been made to design a suitable strategy for enhancing adult neurogenesis, which seems to be deterred due to brain senescence and several neurodegenerative diseases. In this study, we evaluated the effects of ELF-EMF on neurogenesis and memory, following treatment with trimethyltin chloride (TMT) as a neurotoxicant. The mice in all groups (n=56) were injected with BrdU during the experiment for seven consecutive days to label newborn cells. Spatial memory was assessed by the Morris water maze (MWM) test. By the end of the experiment, neurogenesis and neuronal differentiation were assessed in the hippocampus, using immunohistochemistry and Western blot analysis. Based on the findings, exposure to ELF-EMF enhanced spatial learning and memory in the MWM test. ELF-EMF exposure significantly enhanced the number of BrdU+ and NeuN+ cells in the dentate gyrus of adult mice (P<0.001 and P<0.05, resp.). Western blot analysis revealed significant upregulation of NeuroD2 in ELF-EMF-exposed mice compared to the TMT-treated group (P<0.05). These findings suggest that ELF-EMF might have clinical implications for the improvement of neurodegenerative processes and could help develop a novel therapeutic approach in regenerative medicine