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Serotonergic drugs, such as pergolide, have been associated with the development of cardiac valvular myxoid thickening and regurgitation in humans and more recently in rats. These effects are potentially mediated by the 5-hydroxytryptamine [(5-HT).sub.2B] receptor ([5-HT.sub.2B]R). Therefore, we sought to determine whether cyproheptadine, a [5-HT.sub.2B]R antagonist, might prevent toxic valvulopathy in an animal model of pergolide-induced valvular heart disease. For this purpose, 50 male Wistar rats received daily intraperitoneal injections of pergolide (0.5 mg/kg, n = 14), pergofide (0.5 mg/kg) combined with cyproheptadine (10 mg/kg, n = 12), cyprobeptadine (10 mg/kg, n = 12), or no injections (control, n = 12) for 20 wk. Echocardiography was performed blindly at baseline and at 10 and 20 wk followed by pathology. At baseline, no differences between groups were found with echocardiography. At 20 wk, aortic regurgitation was present in all pergolide-treated animals, whereas it was less frequently observed in the other groups (P < 0.0001). For the other valves, this difference was less pronounced. On histopathology, not only aortic but also mitral valves were thicker, myxoid, and exhibited more [5-HT.sub.2B]R-positive cells in pergolide-treated animals compared with the other groups. Moreover, regurgitant aortic and mitral valves were thicker than nonregurgitant aortic and mitral valves. In conclusion, we found that cyproheptadine prevented pergolide-induced valvulopathy in rats, which was associated with a reduced number of [5-HT.sub.2B]R-positive valvular cells. This may have important clinical implications for the prevention of serotonergic drug-induced valvular heart disease. drugs; echocardiography; pathology; valves

Abstract Introduction The spinal cord is a target for many neurosurgical procedures used to treat chronic severe pain. Neuromodulation and neuroablation are surgical techniques based on well-known specific anatomical structures. However, anatomical and electrophysical changes related to the tethered spinal cord make it more difficult to use these procedures. Case presentation We report the case of a 37-year-old Caucasian woman who had several surgical interventions for tethered cord syndrome. These interventions resulted in severe neuropathic pain in her lower back and right leg. This pain was treated by spinal cord stimulation using intra-operative sensory mapping, which allowed the cord's optimal placement in a more caudal position. Conclusion The low-voltage and more caudally placed electrodes are specific features of this treatment of tethered cord syndrome.

Abstract Background In clinical practice and in clinical trials, echocardiography and scintigraphy are used the most for the evaluation of global left ejection fraction (LVEF) and left ventricular (LV) volumes. Actually, poor quality imaging and geometrical assumptions are the main limitations of LVEF measured by echocardiography. Contrast agents and 3D echocardiography are new methods that may alleviate these potential limitations. Methods Therefore we sought to examine the accuracy of contrast 3D echocardiography for the evaluation of LV volumes and LVEF relative to MIBI gated SPECT as an independent reference. In 43 patients addressed for chest pain, contrast 3D echocardiography (RT3DE) and MIBI gated SPECT were prospectively performed on the same day. The accuracy and the variability of LV volumes and LVEF measurements were evaluated. Results Due to good endocardial delineation, LV volumes and LVEF measurements by contrast RT3DE were feasible in 99% of the patients. The mean LV end-diastolic volume (LVEDV) of the group by scintigraphy was 143 ± 65 mL and was underestimated by triplane contrast RT3DE (128 ± 60 mL; p < 0.001) and less by full-volume contrast RT3DE (132 ± 62 mL; p < 0.001). Limits of agreement with scintigraphy were similar for triplane andfull-volume, modalities with the best results for full-volume. Results were similar for calculation of LV end-systolic volume (LVESV). The mean LVEF was 44 ± 16% with scintigraphy and was not significantly different with both triplane contrast RT3DE (45 ± 15%) and full-volume contrast RT3DE (45 ± 15%). There was an excellent correlation between two different observers for LVEDV, LVESV and LVEF measurements and inter observer agreement was also good for both contrast RT3DE techniques. Conclusion Contrast RT3DE allows an accurate assessment of LVEF compared to the LVEF measured by SPECT, and shows low variability between observers. Although RT3DE triplane provides accurate evaluation of left ventricular function, RT3DE full-volume is superior to triplane modality in patients with suspected coronary artery disease.

Abstract The role of structural and functional abnormalities of small vessels in diabetes cardiomyopathy remains unclear. Myocardial contrast echocardiography allows the quantification of myocardial blood flow at rest and during dipyridamole infusion. The aim of the study was to determine the myocardial blood flow reserve in normal rats compared with Streptozotocin-induced diabetic rats using contrast echocardiography. Methods We prospectively studied 40 Wistar rats. Diabetes was induced by intravenous streptozotocin in 20 rats. All rats underwent baseline and stress (dipyridamole: 20 mg/kg) high power intermittent imaging in short axis view under anaesthesia baseline and after six months. Myocardial blood flow was determined and compared at rest and after dipyridamole in both populations. The myocardial blood flow reserve was calculated and compared in the 2 groups. Parameters of left ventricular function were determined from the M-mode tracings and histological examination was performed in all rats at the end of the study. Results At six months, myocardial blood flow reserve was significantly lower in diabetic rats compared to controls (3.09 ± 0.98 vs. 1.28 ± 0.67 ml min-1 g-1; p < 0.05). There were also a significant decrease in left ventricular function and a decreased capillary surface area and diameter at histology in the diabetic group. Conclusion In this animal study, diabetes induced a functional alteration of the coronary microcirculation, as demonstrated by contrast echocardiography, a decrease in capillary density and of the cardiac systolic function. These findings may offer new insights into the underlying mechanisms of diabetes cardiomyopathy.

Abstract Background Recent studies have suggested that diabetes mellitus (DM) may cause left ventricular (LV) dysfunction directly resulting in increased susceptibility to heart failure. Using pinhole collimators and advances in data processing, gated SPECT was recently adapted to image the rat heart. The present study was aimed to assess this new imaging technique for quantifying LV function and remodeling from the Streptozotocin (STZ) rat model compared to controls. Methods Twenty one rats were randomly assigned to control or diabetic group. Six months after the induction of diabetes by STZ, Pinhole 99 m Tc-sestamibi gated SPECT was performed for determining rat LV volumes and function. Post-mortem histopathologic analysis was performed to evaluate the determinant of LV remodeling in this model. Results After six months, the normalized to body weight LV End-systolic volume was significantly different in diabetic rats compared to controls (0.46 ± 0.02 vs 0.33 ± 0.03 μL/g; p = 0.01). The normalized LV End-diastolic volume was also different in both groups (1.51 ± 0.03 vs 0.88 ± 0.05 μL/g; p = 0.001) and the normalized stroke volume was significantly higher in STZ-rats (1.05 ± 0.02 vs 0.54 ± 0.06 μL/g; p = 0.001). The muscular fibers were thinner at histology in the diabetic rats (0.44 ± 0.07 vs 0.32 ± 0.06 AU; p = 0.01). Conclusion Pinhole 99 m Tc-sestamibi gated SPECT can successfully be applied for the evaluation of cardiac function and remodeling in STZ-induced diabetic rats. In this model, LV volumes were significantly changed compared to a control population, leading to a LV dysfunction. These findings were consistent with the histopathological abnormalities. Finally, these data further suggest the presence of diabetes cardiomyopathy.