The Experts below are selected from a list of 50622 Experts worldwide ranked by ideXlab platform
Yue Zhou - One of the best experts on this subject based on the ideXlab platform.
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percutaneous endoscopic lumbar diskectomy and minimally invasive transforaminal lumbar interbody fusion for recurrent lumbar disk herniation
World Neurosurgery, 2017Co-Authors: Yue ZhouAbstract:Objective To compare the clinical outcomes of patients with recurrent lumbar disk disease undergoing percutaneous endoscopic lumbar diskectomy or minimally invasive transforaminal lumbar interbody fusion at a single clinic. Methods From January 2008 to January 2014, 401 consecutive patients with first recurrence of lumbar disk herniation were treated with percutaneous endoscopic lumbar diskectomy (PELD) or minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). These data collected prospectively for analysis were clinical and radiographic results after revision surgery and complications. Results During the follow-up period, postoperative data between both groups showed no significant differences in the mean total postoperative visual analog scale score for leg pain, Japanese Orthopaedic Association score, and Oswestry Disability Index score. The recovery rate was 92.3% in the PELD and 97.4% in the MIS-TLIF group. Regarding satisfactory rate, the PELD group (91.3%) was lower than the MIS-TLIF group (95.2%). Six cases of dural tear were observed in the MIS-TLIF group. The second recurrence occurred in 12 patients in the PELD group. In the PELD group, 1 patient suffered from permanent neurologic deficit. One case of postoperative intervertebral infection was captured in the MIS-TLIF group. Conclusions Both PELD and MIS-TLIF showed favorable clinical outcomes for recurrent disk herniation. Compared with MIS-TLIF, PELD has the following several advantages: 1) performed under local anesthesia; 2) performed with very few approach-related complications, such as dural tear; and 3) rare possibility of fusion disease, such as adjacent segment. However, PELD is also faced with several problems, such as 1) the relative higher rate of postoperative long-term chronic low back pain, and (2) the possibility of recurrence, despite the opportunity being low.
Choonkeun Park - One of the best experts on this subject based on the ideXlab platform.
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percutaneous endoscopic lumbar discectomy as an alternative to open lumbar microdiscectomy for large lumbar disc herniation
Pain Physician, 2016Co-Authors: Kyung Chul Choi, Choonkeun ParkAbstract:BACKGROUND: Remarkable advancements in endoscopic spinal surgery have led to successful outcomes comparable to those of conventional open surgery. Large lumbar disc herniation (LLDH) is a serious condition, resulting in higher surgical failure when accessing the herniated disc. OBJECTIVES: This study compared the outcomes of LLDH treated with percutaneous endoscopic lumbar discectomy (PELD) and open lumbar microdiscectomy (OLM). STUDY DESIGN: Retrospective assessment. METHODS: This retrospective observational study was conducted from January 2011 to June 2012. Forty-four consecutive patients diagnosed with LLDH without cauda equina syndrome who were scheduled to undergo spinal surgery were included. LLDH was defined as herniated disc fragment occupying > 50% of the spinal canal. Clinical outcomes were evaluated using a visual analogue scale (VAS, 0 - 10), functional status was assessed using the Oswestry Disability Index (ODI, 0 - 100%) at 1, 6, and 24 months postoperatively and surgical satisfaction rate (0 - 100%) at final follow up. Radiological variables were assessed by plain radiography. RESULTS: Forty-three patients were included; 20 and 23 patients underwent PELD and OLM, respectively. Both groups exhibited significant improvements in leg and back pain postoperatively (P < 0.001). Although there was no significant difference in leg pain improvement between the groups, improvement in back pain was significantly higher in the PELD group than in the OLM group (4.9 ± 1.5 vs. 2.5 ± 1.0, P < 0.001). The surgical satisfaction rate of the PELD group was significantly higher than that of the OLM group (91.3% ± 6.5 vs. 84.3% ± 5.2, P < 0.001). Mean operating time, hospital stay, and time until return to work were significantly shorter in the PELD group than in the OLM group (67.8 vs. 136.7 minutes, 1.5 vs. 7.2 days, and 4.2 vs. 8.6 weeks; P < 0.001). Disc height (%) decreased significantly from 23.7 ± 3.3 to 19.1 ± 3.7 after OLM (P < 0.001), but did not change significantly after PELD (23.6 ± 3.2 to 23.4 ± 4.2; P = 0.703). The segmental angle of the operated level increased from 10.3° to 15.4° in the PELD group, which was significantly higher than that in the OLM group (9.6° to 11.6°; P = 0.038). In the OLM group, there was one case of fusion due to instability. In the PELD group, one case required revision surgery and another case experienced recurrence. There were no perioperative complications in either group. LIMITATION: The study was retrospective with a small sample size and short follow-up period. CONCLUSION: PELD can be an effective treatment for LLDH, and it is associated with potential advantages, including a rapid recovery, improvements in back pain, and disc height preservation.
Kjell Fuxe - One of the best experts on this subject based on the ideXlab platform.
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adrenalectomy increases the number of substance p and somatostatin immunoreactive nerve cells in the rat lumbar dorsal root ganglia
Brain Research, 1994Co-Authors: Rafael Covenas, M Deleon, Gerson Chadi, A Cintra, Janake Gustafsson, J A Narvaez, Kjell FuxeAbstract:Using an immunocytochemical technique we have analyzed changes in substance P, somatostatin, calcitonin gene-related peptide, and galanin immunoreactivity pattern in the rat dorsal root ganglia. After 7 days of adrenalectomy, sham operated rats were compared with adrenalectomized animals either receiving a daily intraperitoneal injection of 10 mg/kg b.wt. corticosteronev or vehicle. Three lumbar ganglia from each animal were blocked, serially cut, and immunostained for each neuropeptide by means of the biotin-avidin-peroxidase technique. A systematic sampling of immunoreactive ganglion cells was performed and the sample number of immunoreactive ganglion cells was calculated. After adrenalectomy, the number of substance P and somatostatin immunoreactive ganglion cells markedly increased ((means±S.E.M.): 245 ± 68versus123 ± 12 for sham operated animals, P < 0.01 (substance P) and 42 ± 8 as compared to 22 ± 9 for sham operated animals, P < 0.01 (somatostatin)). No significant changes were found in the number of calcitonin gene-related peptide and galanin immunoreactive cells after adrenalectomu. These results suggest that adrenal steroid hormones may reduce the synthesis of both substance P and somatostatin in the dorsal root ganglion cells. Daily treatment with a high dose of corticosterone, mimicking its serum levels after stress, failed to prevent the increase of peptide contents after adrenalectomy. These observations also indicate that a tonic action of corticosterone on mineralocorticoid receptors may be crucial for peptide regulation in the spinal ganglia. These results may be of relevance to adrenalectomy induced changes in sensory mechanisms, neurogenic inflammation and pain transmission and to a role of substance P and somatostatin in these processes.
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short communication adrenalectomy increases the number of substance p and somatostatin immunoreactive nerve cells in the rat lumbar dorsal root ganglia
1994Co-Authors: Gerson Chadi, A Cintra, Kjell FuxeAbstract:Using an immunocytochemical technique we have analyzed changes in substance P, somatostatin, caicitonin gene-related peptide, and galanin immunoreactivity pattern in the rat dorsal root ganglia. After 7 days of adrenalectomy, sham operated rats were compared with adrenalectomized animals either receiving a daily intraperitoneal injection of 10 mg/kg b.wt. corticosterone or vehicle. Three lumbar ganglia from each animal were blocked, serially cut, and immunostained for each neuropeptide by means of the biotin-avidin-peroxidase technique. A systematic sampling of immunoreactive ganglion cells was performed and the sample number of immunoreactive ganglion cells was calculated. After adrenalectomy, the number of substance P and Somatostatin immunoreactive ganglion cells markedly increased ((means + S.E.M.): 245 ___ 68 versus 123 + 12 for sham operated animals, P < 0.01 (substance P) and 42 + 8 as compared to 22 + 9 for sham operated animals, P < 0.01 (somatostatin)). No significant changes were found in the number of calcitonin gene-related peptide and galanin immunoreactive cells after adrenalectomy. These results suggest that adrenal steroid hormones may reduce the synthesis of both substance P and somatostatin in the dorsal root ganglion cells. Daily treatment with a high dose of corticosterone, mimicking its serum levels after stress, failed to prevent the increase of peptide contents after adrenalectomy. These observations also indicate that a tonic action of corticosterone on mineralocorticoid receptors may be crucial for peptide regulation in the spinal ganglia. These results may be of relevance to adrenalectomy induced changes in sensory mechanisms, neurogenic inflammation and pain transmission and to a role of substance P and somatostatin in these processes.
Christopher I Shaffrey - One of the best experts on this subject based on the ideXlab platform.
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radiographic restoration of lumbar alignment after transforaminal lumbar interbody fusion
Neurosurgery, 2009Co-Authors: Jay Jagannathan, Charles A Sansur, Rod J Oskouian, Christopher I ShaffreyAbstract:Objective Restoration of lumbar lordosis is a critical factor in long-term success after lumbar fusions. Transforaminal lumbar interbody fusion (TLIF) is a popular surgical technique in the lumbar spine, but few data exist on change in spinal alignment after the procedure. Methods Eighty patients who underwent TLIF surgery were retrospectively reviewed (minimum follow-up period, 2 years). Standing x-rays were assessed for changes in focal and segmental kyphosis, and restoration of lumbar lordosis. Improvement in spondylolisthesis, sagittal balance, and scoliosis were also assessed. Fusion was assessed as well. Results Eighty operations were performed at 107 levels. Mean presenting lumbar Cobb angle measurement (L1-S1) was 36.3 +/- 4.5 degrees (range, 12-77 degrees). Forty patients (50%) had sagittal imbalance. Mean postoperative Cobb angle (L1-S1) was 55.1 +/- 6.6. Thirty-three of 36 patients with segmental kyphosis (92%) had restoration of lordosis. Improvement in alignment was most prominent at the surgical level (mean increase in lordosis, 20.2 +/- 4.2 degrees). The improvement in lumbar lordosis among patients undergoing multilevel TLIFs (27.3 +/- 3.4 degrees) was significantly higher compared with patients undergoing single-level operations (17.4 +/- 4.4) (Student's t test, P = 0.0004). Thirty of the 40 patients with sagittal imbalance (75%) achieved immediate restoration of normal sagittal balance. The ability to restore normal sagittal balance was correlated with a sagittal imbalance of less than 10 cm (P = 0.0001). Spondylolisthesis was completely corrected at the TLIF site in 90 of 99 levels (91%). Three patients (4%) required reoperation, 2 for implant disengagement and 1 for worsening kyphoscoliosis above the original surgical levels. Two of the 80 patients had pseudoarthrosis; hence, the rate of pseudoarthrosis was 2.5%. Conclusion The TLIF operation is highly effective in improving spinal alignment in patients with degenerative spinal disorders when the appropriate surgical technique is implemented.
Yoon-ho Kim - One of the best experts on this subject based on the ideXlab platform.
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quantum random number generator using photon number path entanglement
Proceedings of SPIE, 2010Co-Authors: Osung Kwon, Youngwook Cho, Yoon-ho KimAbstract:We report an experimental implementation of quantum random number generator based on the photon-number-path entangled state. The photon-number-path entangled state is prepared by means of two-photon Hong-Ou-Mandel quantum interference at a beam splitter. The randomness in our scheme is of truly quantum mechanical origin as it comes from the projection measurement of the entangled two-photon state. The generated bit sequences satisfy the standard randomness test.
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quantum random number generator using photon number path entanglement
Applied Optics, 2009Co-Authors: Osung Kwon, Youngwook Cho, Yoon-ho KimAbstract:We report a quantum random number generator based on the photon-number-path entangled state that is prepared by means of two-photon quantum interference at a beam splitter. The randomness in our scheme is truly quantum mechanical in origin since it results from the projection measurement of the entangled two-photon state. The generated bit sequences satisfy the standard randomness test.
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quantum random number generator using photon number path entanglement
arXiv: Quantum Physics, 2008Co-Authors: Osung Kwon, Youngwook Cho, Yoon-ho KimAbstract:We report a novel quantum random number generator based on the photon-number$-$path entangled state which is prepared via two-photon quantum interference at a beam splitter. The randomness in our scheme is of truly quantum mechanical origin as it comes from the projection measurement of the entangled two-photon state. The generated bit sequences satisfy the standard randomness test.
