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Hsiao-I. Kuo Marom Bikson Abhishek Datta Preet Minhas Walter Paulus Min-Fang Kuo Michael A. Nitsche 《Brain stimulation》2013,6(4):644-648
BackgroundTranscranial direct current stimulation (tDCS) induces long-lasting NMDA receptor-dependent cortical plasticity via persistent subthreshold polarization of neuronal membranes. Conventional bipolar tDCS is applied with two large (35 cm2) rectangular electrodes, resulting in directional modulation of neuronal excitability. Recently a newly designed 4 × 1 high-definition (HD) tDCS protocol was proposed for more focal stimulation according to the results of computational modeling. HD tDCS utilizes small disc electrodes deployed in 4 × 1 ring configuration whereby the physiological effects of the induced electric field are thought to be grossly constrained to the cortical area circumscribed by the ring.ObjectiveWe aim to compare the physiological effects of both tDCS electrode arrangements on motor cortex excitability.MethodstDCS was applied with 2 mA for 10 min. Fourteen healthy subjects participated, and motor cortex excitability was monitored by transcranial magnetic stimulation (TMS) before and after tDCS.ResultsExcitability enhancement following anodal and a respective reduction after cathodal stimulation occurred in both, conventional and HD tDCS. However, the plastic changes showed a more delayed peak at 30 min and longer lasting after-effects for more than 2 h after HD tDCS for both polarities, as compared to conventional tDCS.ConclusionThe results show that this new electrode arrangement is efficient for the induction of neuroplasticity in the primary motor cortex. The pattern of aftereffects might be compatible with the concept of GABA-mediated surround inhibition, which should be explored in future studies directly. 相似文献
115.
Aliasgar V. Moiyadi Prakash M. Shetty Abhishek Mahajan Amar Udare Epari Sridhar 《Acta neurochirurgica》2013,155(12):2217-2225
Background
Intraoperative imaging is increasingly being used in resection of brain tumors. Navigable three-dimensional (3D)-ultrasound is a novel tool for planning and guiding such resections. We review our experience with this system and analyze our initial results, especially with respect to malignant gliomas.Methods
A prospective database for all patients undergoing sononavigation-guided surgery at our center since this surgery’s introduction in June 2011 was queried to retrieve clinical data and technical parameters. Imaging was reviewed to categorize tumors based on enhancement and resectability. Extent of resection was also assessed.Results
Ninety cases were operated and included in this analysis, 75 % being gliomas. The 3D ultrasound mode was used in 87 % cases (alone in 40, and combined in 38 cases). Use of combined mode function [ultrasound (US) with magnetic resonance (MR) images] facilitated orientation of anatomical data. Intraoperative power Doppler angiography was used in one-third of the cases, and was extremely beneficial in delineating the vascular anatomy in real-time. Mean duration of surgery was 4.4 hours. Image resolution was good or moderate in about 88 % cases. The use of the intraoperative imaging prompted further resection in 59 % cases. In the malignant gliomas (51 cases), gross-total resection was achieved in 47 % cases, increasing to 88 % in the “resectable” subgroup.Conclusions
Navigable 3D US is a versatile, useful and reliable intraoperative imaging tool in resection of brain tumors, especially in resource-constrained settings where Intraoperative MR (IOMR) is not available. It has multiple functionalities that can be tailored to suit the procedure and the experience of the surgeon. 相似文献116.
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Tanwar GS Khatri PC Chahar CK Sengar GS Kochar A Tanwar G Chahar S Khatri N Middha S Acharya J Kochar SK Pakalapati D Garg S Das A Kochar DK 《Platelets》2012,23(3):211-216
Thrombocytopenia is commonly seen in Plasmodium vivax malaria, but its prognostic value has not been addressed in children. This prospective study included 676 admitted children of malaria [Plasmodium falciparum (Pf) monoinfection 262, Plasmodium vivax (Pv) monoinfection 380, and mixed (Pf?+?Pv) infection 34], in which thrombocytopenia (platelet count <150?×?10(3)/mm(3) on admission) was found in 442 (65.38%) children [Pf monoinfection 55.3% (145/262), Pv monoinfection 73.16% (278/380), and mixed infection 55.88% (19/34)]. The association of thrombocytopenia was statistically significant with Pv monoinfection [73.16% (278/380)] in comparison to either Pf monoinfection [55.34% (145/262); odds ratio (OR)?=?2.199 (95% confidence interval (CI) 1.577-3.068), p?0.0001] or mixed infection [55.88% (19/34); OR?=?2.152 (95%CI 1.054-4.394), p?=?0.032]. In Pv monoinfection, thrombocytopenia was highest in 0-5 years age group and subsequently decreased with advancing age, whereas in Pf monoinfection it was reverse. Severe thrombocytopenia (platelet count <20?×?10(3)/mm(3)) was present in 16.52% (73/442) children [Pv monoinfection 21.58% (60/278) and Pf monoinfection 8.97% (13/145)]. The risk of developing severe thrombocytopenia was also highest in Pv monoinfection [15.79% (60/380)] in comparison to Pf monoinfection [10.59% (13/262); OR?=?3.591 (95%CI 1.928-6.690), p?0.0001]. Bleeding manifestations were associated in 21.27% (94/442) children [Pf monoinfection 9.92% (26/262), Pv monoinfection 16.58% (63/380), and mixed malaria 14.71% (5/34)]. All the children having bleeding manifestations had thrombocytopenia but low platelet counts were not always associated with abnormal bleeding. The association of severe malaria was significantly more among children having Pv monoinfection with platelet counts <20?×?10(3)/mm(3) [OR?=?2.569 (95%CI 1.196-5.517), p?0.014] with specificity of 88.3% and positive predictive value of 85%. Till today, thrombocytopenia is not included in severe malaria criterion described by WHO, but when platelet counts <20?×?103/mm(3), we advocate it to include as one of the severe malaria criteria. 相似文献
119.
In vivo laser speckle imaging reveals microvascular remodeling and hemodynamic changes during wound healing angiogenesis 总被引:1,自引:0,他引:1
Laser speckle contrast imaging (LSCI) is a high-resolution and high contrast optical imaging technique often used to characterize
hemodynamic changes in short-term physiological experiments. In this study, we demonstrate the utility of LSCI for characterizing
microvascular remodeling and hemodynamic changes during wound healing angiogenesis in vivo. A 2 mm diameter hole was made
in the mouse ear and the periphery of the wound imaged in vivo using LSCI over 12 days. We were able to visualize and quantify
the vascular and perfusion changes that accompanied wound healing in the microenvironment proximal to the wound, and validated
these changes with histology. We found that consistent with the stages of wound healing, microvessel density increased during
the initial inflammatory phase (i.e., day 0–3), stayed elevated through the tissue formation phase (i.e., until day 7) and
returned to baseline during the tissue remodeling phase (i.e., by day 12). Concomitant “wide area mapping” of blood flow revealed
that tissue perfusion in the wound periphery initially decreased, gradually increased from day 3–7, and subsided as healing
completed. Interestingly, some regions exhibited a reestablishment of tissue perfusion approximately 6 days earlier than the
~18 days usually reported for the long term remodeling phase. The results from this study demonstrate that LSCI is an ideal
platform for elucidating in vivo changes in microvascular hemodynamics and angiogenesis, and has the potential to offer invaluable
insights in a range of disease models involving abnormal hemodynamics, such as diabetes and tumors. 相似文献
120.
The present case report highlights that a tense mega-sized aortic root and ascending aorta can mechanically resist the passage of fully inflated (1.5 ml air) balloon to wedge-trace position in the pulmonary artery. Any attempt to push the catheter rather predisposed its recoiling and rebutting into the right ventricle and the cardiac arrhythmia. Inflating continuous cardiac output catheter balloon with lesser volume of air (1 ml) is suggested to overcome this problem. 相似文献