WILLIAM OMAR CONTRERAS LOPEZ
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19 resultados
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- Effects of sexed semen and interactive effects on commercial in vitro embryo production when oocytes are collected from cows of Bos indicus, and Bos taurus breeding and crossbred cows of these subspecies(2015) LOPEZ, William Omar Contreras; ALVIS-MIRANDA, Hernando Raphael; GAMARRA, Andres Felipe; RENDON, Bibiana; BORDA, Diego Armando Vega; ALBICKER, Ulrich; FONOFF, Erich Talamoni; MARTINEZ-DIAZ, MarioA large scale commercial in vitro embryo production and in vitro fertilization record is reported when there was use of oocytes from Bos taurus (BT), Bos indicus (BI), and Bos Taurus/indicus (BT/BI) crossbred subspecies fertilized with sexed (SS) and conventional (CS) semen. The aim of the study was to analyze the impacts of use SS in a commercial embryo production center in Colombia. Non-pregnant (n = 800), healthy, and estrous cycling BT, BI, and BI/BT crossbred cows were selected to be used as oocyte donors. Viable oocytes from 733 ovum pick up sessions in cows of the BT (4663) and BI (7305), BT/BI (3605) groups were matured and fertilized with frozen thawed semen from commercial sires. Of all cultured oocytes (n = 15,573), 52.3% of the embryos (n = 8607) underwent cleavage while 3062(19.7%) developed to the blastocyst stage. For cows of the BT, SS and CS groups, there were similar cleavage rates; however, use of SS decreased blastocyst formation (15.6% versus 18.9%). In the BI group, use of SS increased cleavage rates (59.1% versus 53%, respectively) although there was no effect on blastocyst rate development (22.9% versus 21.9). In the BI/BT groups, use of SS decreased cleavage (44.4% versus 57.1%, respectively) and blastocyst rate development compared with the CS group (15.3% versus 20.1%, respectively). Data from this study indicate embryos from cows of the BT purebred or BI/BT crossbred had less in vitro developmental capacity compared to embryos derived from oocytes of cows that were purebred BI in tropical-subtropical regions.
- Microendoscopy-guided percutaneous cordotomy for intractable pain: case series of 24 patients(2016) FONOFF, Erich Talamoni; LOPEZ, William Omar Contreras; OLIVEIRA, Ywzhe Sifuentes Almeida de; TEIXEIRA, Manoel JacobsenOBJECTIVE The aim of this study was to show that microendoscopic guidance using a double-channel technique could be safely applied during percutaneous cordotomy and provides clear real-time visualization of the spinal cord and surrounding structures during the entire procedure. METHODS Twenty-four adult patients with intractable cancer pain were treated by microendoscopic-guided percutaneous radiofrequency (RF) cordotomy using the double -channel technique under local anesthesia. A percutaneous lateral puncture was performed initially under fluoroscopy guidance to localize the target. When the subarachnoid space was reached by the guiding cannula, the endoscope was inserted for visualization of the spinal cord and surrounding structures. After target visualization, a second needle was inserted to guide the RF electrode. Cordotomy was performed by a standard RF method. RESULTS The microendoscopic double -channel approach provided real-time visualization of the target in 91% of the cases. The other 9% of procedures were performed by the single -channel technique. Significant analgesia was achieved in over 90% of the cases. Two patients had transient ataxia that lasted for a few weeks until total recovery. CONCLUSIONS The use of percutaneous microendoscopic cordotomy with the double-channel technique is useful for specific manipulations of the spinal cord. It provides real-time visualization of the RF probe, thereby adding a degree of safety to the procedure.
conferenceObject Effectiveness and micro-electrodes findings of deep brain stimulation of the STN via a parietal approach in post-infectious previously implanted Parkinson's patients(2016) LOPEZ, W. O. Contreras; BATISTA, L.; AZEVEDO, A.; TEIXEIRA, M. J.; FONOFF, E. T.conferenceObject Characteristic activity pattern obtained by MER to demarcate the borders between the caudal zona incerta and STN for stereotactic treatment of post-traumatic tremor(2014) FONOFF, E. T.; LOPEZ, W. O. Contreras; REIS, P. R.; NEVILLE, I.; NAVARRO, J.; JACOBSEN, M. T.- Aesthetically optimal deep brain stimulation technique in patients with alopecia(2015) FONOFF, Erich Talamoni; TEIXEIRA, Manoel Jacobsen; NASCIMENTO, Clarissa Nobrega Gambarra; LOPEZ, William Omar
- Mystery Case: Brown-Sequard syndrome caused by idiopathic spinal cord herniation(2016) FONOFF, Erich Talamoni; LOPEZ, William Omar Contreras; TEIXEIRA, Manoel JacobsenA 48-year-old man developed numbness in the left leg, which progressed gradually to paresis and urinary incontinence. Neurologic examination revealed a left Brown-Sequard syndrome with leg paresis, mild spasticity, reduced proprioception, and contralateral thermal and painful hypoesthesia below T6. MRI revealed a thoracic spinal cord herniation (SCH) (figure). Idiopathic SCH is relatively rare. Pathogenesis involves a dura mater defect (see video on the Neurology (R) Web site at Neurology.org); herniation develops over a progressive pressure gradient through the dural fissure.(2) Surgical reduction is typically performed if symptoms progress, but mild symptoms may be eligible for conservative treatment and monitoring. Surgical spinal reduction and dural repair usually reverses neurologic deficits.
- Simultaneous bilateral stereotactic procedure for deep brain stimulation implants: a significant step for reducing operation time(2016) FONOFF, Erich Talamoni; AZEVEDO, Angelo; ANGELOS, Jairo Silva dos; MARTINEZ, Raquel Chacon Ruiz; NAVARRO, Jessie; REIS, Paul Rodrigo; SEPULVEDA, Miguel Ernesto San Martin; CURY, Rubens Gisbert; GHILARDI, Maria Gabriela dos Santos; TEIXEIRA, Manoel Jacobsen; LOPEZ, William Omar ContrerasOBJECTIVE Currently, bilateral procedures involve 2 sequential implants in each of the hemispheres. The present report demonstrates the feasibility of simultaneous bilateral procedures during the implantation of deep brain stimulation (DBS) leads. METHODS Fifty-seven patients with movement disorders underwent bilateral DBS implantation in the same study period. The authors compared the time required for the surgical implantation of deep brain electrodes in 2 randomly assigned groups. One group of 28 patients underwent traditional sequential electrode implantation, and the other 29 patients underwent simultaneous bilateral implantation. Clinical outcomes of the patients with Parkinson's disease (PD) who had undergone DBS implantation of the subthalamic nucleus using either of the 2 techniques were compared. RESULTS Overall, a reduction of 38.51% in total operating time for the simultaneous bilateral group (136.4 +/- 20.93 minutes) as compared with that for the traditional consecutive approach (220.3 +/- 27.58 minutes) was observed. Regarding clinical outcomes in the PD patients who underwent subthalamic nucleus DBS implantation, comparing the preoperative off-medication condition with the off-medication/on-stimulation condition 1 year after the surgery in both procedure groups, there was a mean 47.8% +/- 9.5% improvement in the Unified Parkinson's Disease Rating Scale Part III (UPDRS-III) score in the simultaneous group, while the sequential group experienced 47.5% +/- 15.8% improvement (p = 0.96). Moreover, a marked reduction in the levodopa-equivalent dose from preoperatively to postoperatively was similar in these 2 groups. The simultaneous bilateral procedure presented major advantages over the traditional sequential approach, with a shorter total operating time. CONCLUSIONS A simultaneous stereotactic approach significantly reduces the operation time in bilateral DBS procedures, resulting in decreased microrecording time, contributing to the optimization of functional stereotactic procedures.
conferenceObject Rat brain basal ganglia imaged with optical coherence tomography: Feasibility and future perspectives(2015) ANGELOS, J. S. dos; LOPEZ, W. O. C.; MARTINEZ, R. C. R.; REIS, P. R.; TAKIMURA, C. K.; TEIXEIRA, M. J.; LEMOS NETO, P. A.; FONOFF, E. T.conferenceObject Surgical treatment of post-traumatic midbrain resting-kinetic tremor with stereotactic lesions with MER of the zona incerta(2015) AZEVEDO, A. R. C.; CONTRERAS, W. O.; REIS, P. R.; CURY, R. G.; SILVA, F. E. F.; NAVARRO, J.; FONOFF, E. T.article 11 Citação(ões) na Scopus Pain Relief in CRPS-II after Spinal Cord and Motor Cortex Simultaneous Dual Stimulation(2016) LOPEZ, William O. C.; BARBOSA, Danilo C.; TEIXEIRA, Manoel J.; PAIZ, Martin; MOURA, Leonardo; MONACO, Bernardo A.; FONOFF, Erich T.We describe a case of a 30-year-old woman who suffered a traumatic injury of the right brachial plexus, developing severe complex regional pain syndrome type II (CRPS-II). After clinical treatment failure, spinal cord stimulation (SCS) was indicated with initial positive pain control. However, after 2 years her pain progressively returned to almost baseline intensity before SCS. Additional motor cortex electrode implant was then proposed as a rescue therapy and connected to the same pulse generator. This method allowed simultaneous stimulation of the motor cortex and SCS in cycling mode with independent stimulation parameters in each site. At 2 years follow-up, the patient reported sustained improvement in pain with dual stimulation, reduction of painful crises, and improvement in quality of life. The encouraging results in this case suggests that this can be an option as add-on therapy over SCS as a possible rescue therapy in the management of CRPS-II. However, comparative studies must be performed in order to determine the effectiveness of this therapy.