• Applied Microscopy
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• 제19권2호
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• pp.99-118
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• 1989

The cardiotoxic effects of acute and chronic administration of adriamycin (ADR) were evaluated in A/J Swiss albino mice. In acute studies, male mice received intravenous ADR, 5mg or 15mg/kg per day for 3 or 1day and were sacrifice 12 hours later. Because the glutathione-glutathione peroxidase system is major pathway for free radical detoxication, glutathione levels and glutathione peroxidase activity was measured. In acute studies, ADR-treated mice exhibited significantly decreased levels(p<0.05) of total glutathione and unchanged levels of oxidized glutathione and percentage of oxidized glutathione. The earliest myocardial fine structural alterations included swelling and degeneration of mitochondria and dilatation of sarcoplasmic reticulum at all dosage of acute models. In chronic studies, mice received 5mg/kg ADR once a week for up to 16 weeks. Levels of total and reduced glutathione were decreased significantly(p<0.01) and oxidized glutathione and percentage of oxidized glutathione were increased significantly (p<0.05). Chronic myocardial lesions included perinuclear vacuolization, seperation of myofibrils and the fasciae adherens of intercalated disc and hypercontraction band within myocyte. Glutathione peroxidase activity reduced significantly (p<0.01) in any group of acute and chronic ADR-treated animals. Test for lipid peroxidation(malondialdehyde) was increased significantly(P<0.01). Thus, we conclude 1) ADR significantly lowers glutathione levels in heart tissue, and 2) cellular damage progress produced by alteration of this system in mouse models of ADR cardiotoxicity. These results suggest that the glutathione-glutathione peroxidase system may be involved in the modulation of ADR-induced cardiotoxicity.

• Journal of Korean Neurosurgical Society
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• 제46권4호
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• pp.285-291
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• 2009

Objective : This study examined the change of range of motion (ROM) at the segments within the dynamic posterior stabilization, segments above and below the system, the clinical course and analyzed the factors influencing them. Methods : This study included a consecutive 27 patients who underwent one-level to three-level dynamic stabilization with Bioflex system at our institute. All of these patients with degenerative disc disease underwent decompressive laminectomy with/without discectomy and dynamic stabilization with Bioflex system at the laminectomy level without fusion. Visual analogue scale (VAS) scores for back and leg pain, whole lumbar lordosis (from L1 to S1), ROMs from preoperative, immediate postoperative, 1.5, 3, 6, 12 months at whole lumbar (from L1 to S1), each instrumented levels, and one segment above and below this instrumentation were evaluated. Results : VAS scores for leg and back pain decreased significantly throughout the whole study period. Whole lumbar lordosis remained within preoperative range, ROM of whole lumbar and instrumented levels showed a significant decrease. ROM of one level upper and lower to the instrumentation increased, but statistically invalid. There were also 5 cases of complications related with the fixation system. Conclusion : Bioflex posterior dynamic stabilization system supports operation-induced unstable, destroyed segments and assists in physiological motion and stabilization at the instrumented level, decrease back and leg pain, maintain preoperative lumbar lordotic angle and reduce ROM of whole lumbar and instrumented segments. Prevention of adjacent segment degeneration and complication rates are something to be reconsidered through longer follow up period.

• 한국정밀공학회지
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• 제27권1호
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• pp.134-141
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• 2010

This study analyzed the regional morphological and mechanical characteristics of vertebrae by using micro-computed tomography (micro-CT) and micro finite element analysis (FEA). For the present study, the $12^{th}$ human thoracic vertebral bones (an 85-years female and a 48-years male) were used. These were scanned by using micro-CT. Structural parameters were evaluated from the acquired 20 image data for fifteen $4{\times}4mm^2$ regions (five regions in respective layers of superior, middle and inferior part) in the thoracic vertebral trabecular bones. $4{\times}4{\times}4mm^3$ cubic finite element models of each regions were created at $70{\mu}m$ voxel resolution to investigate effective modulus ($E^+$). The present study indicated that there were significant differences in morphological and elastic mechanical characteristics of each region. There are close relationship between effective modulus and structural model index (SMI) in the bone of the 48-years male and between effective modulus and bone volume fraction (BV/TV) in the bone of the 85-years female. In addition, the effective modulus of central regions is about 80% stiffer than that of lateral regions at transverse plane. These findings may be likely to explain the previous result that a change of loading distribution of the vertebral trabecular bones is caused by spinal curvature and nucleus pulpous degeneration of the intervertebral disc.

• Journal of Korean Neurosurgical Society
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• 제48권4호
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• pp.342-346
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• 2010

Objective : This study assessed the efficacy of anterior cervical discectomy and fusion (ACDF) with cage alone compared with ACDF with plate instrumentation for radiologic and clinical outcomes in two-level cervical degenerative disease. Methods : Patients with cervical degenerative disc disease from September 2004 to December 2009 were assessed retrospectively. A total of 42 patients received all ACDF at two-level cervical lesion. Twenty-two patients who underwent ACDF with cage alone were compared with 20 patients who underwent ACDF with plate fixation in consideration of radiologic and clinical outcomes. Clinical outcomes were assessed using Robinson's criteria and posterior neck pain, arm pain described by a 10 point-visual analog scale. Fusion rate, subsidence, kyphotic angle, instrument failure and the degenerative changes in adjacent segments were examined during each follow-up examination. Results : VAS was checked during each follow-up and Robinson's criteria were compared in both groups. Both groups showed no significant difference. Fusion rates were 90.9% (20/22) in ACDF with the cage alone group, 95% (19/20) in ACDF with the plate fixation group (p = 0.966). Subsidence rates of ACDF with cage alone were 31.81% (7/22) and ACDF with plate fixation were 30% (6/20) (p = 0.928). Local and regional kyphotic angle difference showed no significant difference. At the final follow-up, adjacent level disease developed in 4.54% (1/22) of ACDF with cage alone and 10% (2/20) of ACDF with plate fixation (p= 0.654). Conclusion : In two-level ACDF, ACDF with cage alone would be comparable with ACDF with plate fixation with regard to clinical outcome and radiologic result with no significant difference. We suggest that the routine use of plate and screw in 2-level surgery may not be beneficial.

• Journal of Korean Neurosurgical Society
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• 제51권6호
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• pp.343-349
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• 2012

Objective : Pedicle-based dynamic stabilization systems, in which semi-rigid rods or cords are used to restrict or control spinal segmental motion, aim to reduce or eliminate the drawbacks associated with rigid fusion. In this study, we analyzed the two-year clinical outcomes of patients treated with the NFlex (Synthes Spine, Inc.), a pedicle-based dynamic stabilization system. Methods : Five sites participated in a retrospective study of 72 consecutive patients who underwent NFlex stabilization. Of these 72 patients, 65 were available for 2-year follow-up. Patients were included based on the presence of degenerative disc disease (29 patients), degenerative spondylolisthesis (16 patients), lumbar stenosis (9 patients), adjacent segment degeneration (6 patients), and degenerative lumbar scoliosis (5 patients). The clinical outcome measures at each assessment were Visual Analogue Scale (VAS) to measure back pain, and Oswestry Disability Index (ODI) to measure functional status. Radiographic assessments included evidence of instrumentation failure or screw loosening. Results : Sixty-five patients (26 men and 39 women) with a mean age of 54.5 years were included. Mean follow-up was 25.6 months. The mean VAS score improved from 8.1 preoperatively to 3.8 postoperatively, representing a 53% improvement, and the ODI score from 44.5 to 21.8, representing a 51% improvement. Improvements in pain and disability scores were statistically significant. Three implant-related complications were observed. Conclusion : Posterior pedicle-based dynamic stabilization using the NFlex system seems effective in improving pain and functional scores, with sustained clinical improvement after two years. With appropriate patient selection, it may be considered an effective alternative to rigid fusion.

• 대한치과교정학회지
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• 제30권2호
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• pp.235-243
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• 2000

측두하악관절의 자기공명영상(MRI)은 하악과두와 관절원판(disc)의 관계를 잘 보여주기 때문에 관절내장증(internal derangement)의 진단을 위해 매우 유용하다. 이번 연구의 목적은 서울대학교 치과병원 교정과에 내원한 측두하악관절 장애가 의심되는 환자들의 MRI 자료를 평가하여 관절 내장증의 유무, 발생빈도 및 심도를 파악하는 것이다. MRI를 촬영한 표본은 남자 10명, 여자 40명으로 총 50명이었고 평균 나이는 22.9세였다. 전체 50명 중에 43명에서 positive finding이 관찰되었다. Positive finding을 나타낸 환자 중에서 전방관절원판변위(anterior disc displacement : ADD)는 비정복성이 $56\%$로 가장 많았으며, 양쪽 관절에서 동시에 일어난 경우가 $65\%$로 가장 많았다. Positive finding을 나타낸 환자를 Angle 분류 시, II급 1류 부정교합 환자가 $39.6\%$, II급 2류 부정교합 환자가 $2.3\%$로 II급 부정교합이 $41.9\%$로 가장 많았고, I급 부정교합 환자는 $37.2\%$, III급 부정교합 환자가 $18.6\%$, 확인 안된 경우가 $2.3\%$였다. Positive finding을 나타낸 환자 중에서 안면 비대칭 환자는 $8.6\%$, 개교 환자는 $55.8\%$였다. 결론적으로 측두하악관절의 관절 내장증을 가진 환자에서는 II급 부정교합이 차지하는 비율이 매우 크다고 할 수 있다. 개교나 안면 비대칭은 측두하악관절 장애로 인한 보상적 또는 비보상적인 변형에 의해 나타날 수 있으며 퇴행성 관절 질환으로 진행되는 과정중 안면 골격 개조의 결과로 보인다. 그러므로 개교 및 안면 비대칭이 있는 환자는 교정 치료 시작 전에 측두하악관절의 이상 유무를 MRI로 확인(screening)할 것이 권장된다. 측두하악관절 장애가 있는 경우 교정 치료 후에도 재발의 경향이 크고 측두하악관절에 대한 계속적인 관찰이 필요하므로 감별진단이 필수적이다.

• Journal of Korean Neurosurgical Society
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• 제65권4호
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• pp.539-548
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• 2022

Objective : Although full-endoscopic lumbar interbody fusion (Endo-LIF) has been tried as the latest alternative technique to minimally invasive transforaminal lumbar interobody fusion (MIS-TLIF) since mid-2010, the evidence is still lacking. We compared the clinical outcome and safety of Endo-LIF to MIS-TLIF for lumbar degenerative disease. Methods : We systematically searched electronic databases, including PubMed, EMBASE, and Cochrane Library to find literature comparing Endo-LIF to MIS-TLIF. The results retrieved were last updated on December 11, 2020. The perioperative outcome included the operation time, blood loss, complication, and hospital stay. The clinical outcomes included Visual analog scale (VAS) of low back pain and leg pain and Oswestry disability index (ODI), and the radiological outcome included pseudoarthosis rate with 12-month minimum follow-up. Results : Four retrospective observational studies and one prospective observational study comprising 423 patients (183 Endo-LIF and 241 MIS-TLIF) were included, and the pooled data analysis revealed low heterogeneity between studies in our review. Baseline characteristics including age and sex were not different between the two groups. Operation time was significantly longer in Endo-LIF (mean difference [MD], 23.220 minutes; 95% confidence interval [CI], 10.669-35.771; p=0.001). However, Endo-LIF resulted in less perioperative blood loss (MD, -144.710 mL; 95% CI, 247.941-41.478; p=0.023). Although VAS back pain at final (MD, -0.120; p=0.586), leg pain within 2 weeks (MD, 0.005; p=0.293), VAS leg pain at final (MD, 0.099; p=0.099), ODI at final (MD, 0.141; p=0.093) were not different, VAS back pain within 2 weeks was more favorable in the Endo-LIF (MD, -1.538; 95% CI, -2.044 to -1.032; p<0.001). On the other hand, no statistically significant group difference in complication rate (relative risk [RR], 0.709; p=0.774), hospital stay (MD, -2.399; p=0.151), and pseudoarthrosis rate (RR, 1.284; p=0.736) were found. Conclusion : Relative to MIS-TLIF, immediate outcomes were favorable in Endo-LIF in terms of blood loss and immediate VAS back pain, although complication rate, mid-term clinical outcomes, and fusion rate were not different. However, the challenges for Endo-LIF include longer operation time which means a difficult learning curve and limited surgical indication which means patient selection bias. Larger-scale, well-designed study with long-term follow-up and randomized controlled trials are needed to confirm and update the results of this systematic review.