Home About us Contact
|
Home About us Contact | ||
|
|
||
Targeted Area (targeted + area)
Selected AbstractsMRI-based evaluation of locus and extent of neurotoxic lesions in monkeys ,HIPPOCAMPUS, Issue 4 2001e Málková Abstract To minimize the variability in the extent of lesions made by injections of the excitotoxin ibotenic acid in rhesus monkeys, we developed and validated an MRI-based method to determine the efficacy of the injections soon after surgery. T2-weighted MR images were obtained 6,11 days after surgery from 17 brain hemispheres of monkeys that had received bilateral lesions of either the hippocampal formation (HF), perirhinal cortex, or parahippocampal cortex. The extent of lesion estimated from the hypersignal that appeared in and outside of the targeted area on these MR images was compared with the extent of damage assessed histologically after survival periods ranging from 120,370 days. Highly significant correlations (r values between 0.85,0.99) were found between these two measures for several regions in the medial temporal lobe. Based on this finding, lack of hypersignal in the targeted area of some Ss was followed by successful reinjection of the neurotoxin to create more complete cell loss prior to the postoperative phase of the study. We also assessed the relationship between a postoperative reduction in HF volume, measured from T1-weighted MR images, and the extent of damage determined histologically in 14 hemispheres of monkeys with bilateral excitotoxic HF lesions. The HF volume decreases sharply after surgery until 40,50 days postoperatively, after which there is only a minor further decrease. Based on this finding, we obtained T1-weighted MR images at least 44 days but in most cases close to 1 year after surgery. A highly significant positive correlation (r = 0.95, P < 0.001) was found between neuronal damage and volume reduction, with nearly complete neuronal damage (96,99%) corresponding to a volume reduction of 68,79%. These MRI-based methods thus provide an accurate in vivo evaluation of the locus and extent of neurotoxic lesions. Application of these methods can ensure that each animal in the experiment is used effectively. Hippocampus 2001;11:361,370. Published 2001 Wiley-Liss, Inc. [source] Robot-Assisted Isolation of the Pulmonary Veins with Microwave EnergyJOURNAL OF CARDIAC SURGERY, Issue 1 2006F.A.C.S., J. Michael Smith M.D. This study evaluated the feasibility of performing a minimally invasive left atrial isolation on a beating heart using the da Vinci Robotic Surgical System and a flexible microwave probe (Flex 10 by AFx, Inc., Fremont, CA, USA), and the reliability of exit block pacing to confirm transmurality of the lesions created. Methods: On six canines, the Flex 10 probe was passed around the left atrium posterior to the superior vena cava, through the transverse sinus, and back through the oblique sinus via a right-chest-only approach using the da Vinci Robotic Surgical System. Prior to ablation, pacing outside the atrial cuff was confirmed. Ablation was then carried out on the beating heart and repeated (as needed) until electrical isolation was demonstrated by exit block pacing. Probe position was confirmed at the completion of the procedure via sternotomy. Analysis included acute histologic and gross examination of the targeted area. Results: There was no significant difference (p = 0.110) in procedure time, although it decreased 39.6% from the first three cases to the last three cases. Electrical evidence of electrical left atrial isolation was achieved in all subjects. Acute histologic examination confirmed transmurality inconsistently. Additionally, in two animals, the Flex 10 probe was found to be anterior to the left atrial appendage. All animals survived the procedure. Conclusion: A minimally invasive left atrial isolation procedure using monopolar microwave energy with the da Vinci Robotic Surgical System is simple and feasible. However, despite creating an electrical block, transmurality was not demonstrated consistently and further confirmation of catheter positioning is necessary during a right-chest-only approach. [source] Hypothalamic Deep Brain Stimulation for the Treatment of Chronic Cluster Headaches: A Series ReportNEUROMODULATION, Issue 1 2004Angelo Franzini MD Abstract The objective of this study was to introduce a new surgical treatment for drug-resistant chronic cluster headaches (CH). Because recent functional studies suggested that a hyperactivity of the posterior hypothalamus might be the primary cause of Cluster Headaches (CH) bouts, we designed a prospective study to explore the therapeutic effectiveness of chronic high-frequency stimulation of this region for the treatment of CH. Nine electrodes were stereotactically implanted in the posterior hypothalamus in eight patients suffering from intractable chronic CH. The stereotactic coordinates of the targeted area were 3 mm behind the mid-commissural point, 5 mm below the mid-commissural point, and 2 mm lateral from the midline. Since initiating this treatment in our center, all of the eight patients have improved. Steroid administration has been progressively withdrawn. All of the patients reported that they were pain-free at 1,26 months of follow-up. Three of the eight patients were pain-free without any medication while five of the eight required low doses of methysergide and/or verapamil. No noxious side effects from chronic high-frequency hypothalamic stimulation have been observed nor have we encountered any acute complications from the implant procedure. Tolerance was not observed. We conclude that these preliminary results indicate that hypothalamic stimulation is safe and effective for the treatment of drug-resistant, chronic CH. In addition, these data confirm the "central" pathogenesis for chronic CH. [source] Successful Implantation of a Coronary Sinus Lead After Stenting of a Coronary Vein StenosisPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2003BERRY M. VAN GELDER Dislodgment of the coronary sinus lead was observed in a 79-year-old patient 8 months after implantation of a biventricular pacing system. A severe stenosis in the posterolateral branch, in which the lead was previously positioned, prohibited reinsertion of the lead. Because no other branches with adequate anatomy for lead insertion were available in the targeted area, the stenosis was dilated and stented. Subsequently, the left ventricular lead could be reimplanted in the same vessel. (PACE 2003; 26:1904,1906) [source] Impact study of the 2003 North Atlantic THORPEX Regional CampaignTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 615 2006Nadia Fourrié Abstract An experiment took place during autumn 2003 with the aim of testing the feasibility of an operational targeting of observations over the North Atlantic Ocean in the context of the international programme THORPEX. The purpose of this paper is to evaluate the impact of these additional observations in the French operational model ARPEGE during the last three weeks of the campaign. Results are shown for large regions over and around the North Atlantic Ocean and for specific verification areas. Over Europe, the addition of observations is slightly beneficial for the forecast, mostly in the low troposphere over wide areas and above 100 hPa. However, the impact of extra data is more significant but also more mixed for the dedicated verification areas: they are case, forecast-range and level dependent. In addition, the information content is studied with the Degrees of Freedom for Signal (DFS) for the evaluation of the observation impact on the analysis of one case of December 2003. Firstly, the variations of the DFS have been illustrated in a simplified data assimilation system. It has been found for that case that satellite data have the most important global contribution to the overall analysis, especially the humidity sensitive infrared radiances. For the conventional data, the wind measurements of the aircraft and from the geostationary satellites are the most informative. For the targeted area, the data from aircraft and the dropsondes have the largest DFS. It has been noted that the DFS of the dropsondes located in the sensitivity maximum is larger than the other one even if there is no link between the DFS and the forecast. However, the impact of the dropsondes grows with respect to the forecast range and leads to an improvement of the forecast for this case. Copyright © 2006 Royal Meteorological Society [source] Phase III trial of methotrexate, vinblastine, doxorubicin, and cisplatin versus carboplatin and paclitaxel in patients with advanced carcinoma of the urothelium,CANCER, Issue 8 2004A trial of the Eastern Cooperative Oncology Group Abstract BACKGROUND The regimens of carboplatin plus paclitaxel (CP) and methotrexate, vinblastine, doxorubicin, and cisplatin (M-VAC) were compared in patients with advanced urothelial carcinoma. METHODS Patients with metastatic urothelial carcinoma were randomized to receive either CP (paclitaxel at a dose of 225 mg/m2 and carboplatin [targeted area under the concentration-time curve (AUC) of 6] given every 21 days) or the standard M-VAC dosage. RESULTS Eighty-five patients were randomized to the respective treatment regimens (41 to CP and 44 to M-VAC). Response rates and overall survival were similar for both treatment arms. Patients treated with CP had an overall response rate of 28.2% (95% binomial confidence interval, 15.0,44.9%) compared with an overall response rate of 35.9% for the M-VAC arm (95% binomial confidence interval, 21.2,52.8%) (P = 0.63, Fisher exact test). The median progression-free survival among patients who were treated with M-VAC was 8.7 months and was 5.2 months for patients receiving CP (P = 0.24, log-rank test). At a median follow-up of 32.5 months, the median survival for patients treated with M-VAC was 15.4 months versus 13.8 months for patients treated with CP (P = 0.65, log-rank test). Patients treated with M-VAC were found to have more severe worst-degree toxicities compared with patients treated with CP (P = 0.0001). There were no significant differences with regard to quality of life as assessed by the Functional Assessment of Cancer Therapy,Bladder (FACT-BL) instrument (P = 0.33). CONCLUSIONS Interpretation of the results of this study must be made with caution because the study failed to reach its accrual goal. Patients treated with CP had a median survival of 13.8 months compared with 15.4 months for patients treated with M-VAC. Patients treated with CP appeared in general to better tolerate their treatment; however, there were no significant differences noted with regard to measured quality of life parameters. Cancer 2004. © 2004 American Cancer Society. [source] Minding the gap: Filling a void in community college leadership developmentNEW DIRECTIONS FOR COMMUNITY COLLEGES, Issue 149 2010Dale F. Campbell This chapter describes the development of a community college leadership program that integrates interpersonal competency building with the process of personality and work-style profiling and individualized instruction in targeted areas for improvement. [source] | ||||||||||