Growth hormone activates X-box binding protein 1 in a sexually dimorphic manner through the extracellular signal-regulated protein kinase and CCAAT/enhancer-binding protein ß pathway in rat liver.

Growth hormone (GH) has multiple physiological roles, acting on many organs. In order to investigate its roles in rat liver, we tried to identify novel genes whose transcription was regulated by GH. We identified X-box binding protein 1 (Xbp1) as a candidate gene. XBP1 is a key transcription factor activated in response to endoplasmic reticulum (ER) stress. The purpose of this study was to investigate the mode of action of GH on XBP1, including the relation with ER stress, sex-dependent expression of the mRNA, and the signaling pathway. Intravenous administration of GH rapidly and transiently increased Xbp1 mRNA in hypophysectomized rat livers. Neither phosphorylated inositol-requiring-1α (IRE1α) nor phosphorylated PKR-like ER kinase (PERK) increased, suggesting that Xbp1 expression is induced by an ER stress-independent mechanism. The active form of XBP1(S) protein was increased by GH administration and was followed by an increased ER-associated dnaJ protein 4 (ERdj4) mRNA level. XBP1(S) protein levels were predominantly identified in male rat livers with variations among individuals similar to those of phosphorylated signal transducer and activator of transcription 5B (STAT5B), suggesting that XBP1(S) protein levels are regulated by the sex-dependent secretary pattern of GH. The GH signaling pathway to induce Xbp1 mRNA was examined in rat hepatoma H4IIE cells. GH induced the phosphorylation of CCAAT/enhancer-binding protein ß (C/EBPß) following extracellular signal-regulated protein kinase (ERK) phosphorylation. Taken together, the results indicated that XBP1 is activated by GH in rat liver in a sexually dimorphic manner via ERK and C/EBPß pathway.

Syncephalastrum racemosum amine oxidase with high catalytic efficiency toward ethanolamine and its application in ethanolamine determination.

Our screening study yielded a copper amine oxidase (SrAOX) from Syncephalastrum racemosum, which showed much higher affinity and catalytic efficiency toward ethanolamine (EA) than any other amine oxidase (AOX). Following purification of the enzyme to electrophoretic homogeneity from a cell-free extract, the maximum activity toward EA was detected at pH 7.2-7.5 and 45 °C. The SrAOX complementary DNA (cDNA) was composed of a 2052-bp open reading frame encoding a 683-amino acid protein with a molecular mass of 77,162 Da. The enzyme functions as a homodimer. The deduced amino acid sequence of SrAOX showed 55.3 % identity to Rhizopus delemar AOX and contains two consensus sequences of Cu-AOX, NYDY, and HHQH, suggesting SrAOX is a type 1 Cu-AOX (i.e., a topaquinone enzyme). Structural homology modeling showed that residues (112)ML(113), (141)FADTWG(146) M158, and N318 are unique, and T144 possibly characterizes the substrate specificity of SrAOX. The recombinant enzyme (rSrAOX) was produced using Escherichia coli. Steady-state kinetic analysis of rSrAOX activity toward EA (pH 7.5 and 45 °C) gave K m and k cat values of 0.848 ± 0.009 mM and 9.11 ± 0.13 s(-1), respectively. The standard curves were linear between 0.1 and 2 mM EA, and 10 µg mL(-1)-2.5 mg mL(-1) (15 µM-3.6 mM) phosphatidylethanolamine using Streptomyces chromofuscus phospholipase D, respectively, was sufficiently sensitive for clinical use.

[Establishment of Endoscopic Spinal Neurosurgery and its Current Status].

Percutaneous endoscopic lumbar discectomy(PELD)has been used as a standard surgical technique for lumbar disc herniation at the Southern TOHOKU Healthcare Group since its introduction in 2009. We present our clinical experiences with PELD for 6 years and discuss the decision-making process for its surgical indication with a review of the pertinent literature. PELD can be performed under both local anesthesia and general anesthesia, and requires only a stab wound for surgery and 3 days of hospitalization. Our surgical results showed generally satisfactory outcomes; however, a salvage surgery was required for 10 of the 96 patients(10.4%)because of early recurrence, insufficient removal of the transligamentous disc fragment, and coexistent canal stenosis. Surgery was discontinued because of unbearable intraoperative pain in one patient each undergoing transforaminal approach and extraforaminal approach under local anesthesia. Although our experience is limited, PELD is considered a promising minimally invasive surgery for lumbar disc herniation. It is generally indicated for patients who are young, sports oriented, or extremely busy. Recurrent disc herniation after microdiscectomy, high risk for general anesthesia, and emergency are considered ideal indications for this technique. Since PELD is a newer technique with a high learning curve, further study, continuous training, and education are required before its widespread implementation. Careful selection of patients is crucial to achieve satisfactory surgical results.

Three-dimensional kinematic analysis of the cervical spine after anterior cervical decompression and fusion at an adjacent level: a preliminary report.

PURPOSE: Development of adjacent segment degeneration following anterior cervical decompression and fusion (ACDF) is still controversial, as adjacent-level kinematics is poorly understood. This study reports preliminary data from a high-accuracy 3D analysis technique developed for in vivo cervical kinematics. METHODS: From nine cervical spondylosis patients, four underwent single-level ACDF, and five underwent two-level ACDF using cylindrical titanium cage implant(s). Pre- and post-surgical CT scans were taken in flexion, neutral and extended positions, allowing us to compute segmental ranges of motion for rotation and translation, and 3D disc-height distributions. Differences in segmental motions and disc-height between fused and adjacent levels were analyzed with a Wilcoxon signed-rank test. Results are presented as mean ± SEM. RESULTS: The flexion/extension angular-ROM at the fusion level decreased after surgery (7.46 ± 1.17° vs. 3.14 ± 0.56°, p < 0.003). The flexion/extension angular-ROM at one caudal adjacent level to the fusion level (3.97 ± 1.29°) tended to be greater post-operatively (6.11 ± 1.44°, p = 0.074). Translation in the anterior-posterior direction during flexion/extension at the fusion level decreased after surgery (1.22 ± 0.20 mm vs. 0.32 ± 0.11 mm, p < 0.01). No differences were found in adjacent-level disc heights between both study time-points. CONCLUSIONS: This study showed increased segmental motion in flexion/extension angular-ROM at one level adjacent to ACDF. However, increases in the rotational angular-ROM were not statistically significant when cranial/caudal adjacent levels were analyzed separately. This preliminary study highlighted the capabilities of a 3D-kinematic analysis method to detect subtle changes in kinematics and disc height at the adjacent levels to ACDF. Thus, reliable evidence related to ACDF's influence on adjacent-level cervical kinematics can be collected.

A case of pathologically confirmed streptococcal infection-related IgA vasculitis with associated glomerulonephritis and leukocytoclastic cutaneous vasculitis.

We report the case of an 80 year-old woman who developed bilateral lower extremity purpura and renal impairment with proteinuria a few days after a transient fever (day 0). High levels of both anti-streptolysin-O antibody (ASO) and anti-streptokinase antibody (ASK), as well as low levels of coagulation factor XIII in serum were noted. Skin biopsy was performed and showed a leukocytoclastic vasculitis with deposition of IgA and C3 in the cutaneous small vessels, indicating IgA vasculitis in the skin. After initiation of oral prednisolone, the skin lesions showed significant improvement. However, renal function and proteinuria gradually worsened from day 12. Kidney biopsy was performed on day 29, which demonstrated a necrotizing and crescentic glomerulonephritis with mesangial deposition of IgA and C3. In addition, the deposition of galactose-deficient IgA1 (Gd-IgA1) was positive on glomeruli and cutaneous small vessels, indicating that the purpura and glomerulonephritis both shared the same Gd-IgA1-related pathogenesis. In addition, the association between the acute streptococcal infection and the IgA vasculitis was confirmed by the deposition of nephritis-associated plasmin receptor (NAPlr) in glomeruli. The patient was treated with steroid pulse and intravenous cyclophosphamide, in addition to the oral prednisolone treatment. Renal function and proteinuria gradually improved, but did not completely recover, as is typically seen with courses of IgA vasculitis in the elderly. In this case, the streptococcal infectionrelated IgA vasculitis was confirmed pathologically by the deposition of both NAPlr and Gd-IgA1 in glomeruli, as well as Gd-IgA1 in the cutaneous small vessels.

[Concomitant intracerebral hemorrhage and cerebral infarction in moyamoya disease: a case report].

We encountered a case of moyamoya disease which exhibited intracerebral hemorrhage with intraventricular hemorrhage followed by cerebral infarction in a short time. A 39-year-old female presenting with sudden onset disturbance of consciousness was admitted to our hospital. Radiological investigation on admission revealed intracerebral hemorrhage in the left temporal lobe and intraventricular hemorrhage due to moyamoya disease. The patient experienced cerebral infarction of the left frontotemporal area with brain swelling after 20 hours had passed. In spite of immediate left frontotemporal craniectomy and evacuation of the hematoma, she died 9 days after the operation. This case indicates that adequate control of intracranial pressure such as ventricular drainage is important to prevent progression of ischemic attack at an early stage. But it is not known what case of cerebral hemorrhage due to moyamoya disease would be complicated by cerebral infarction. The detection of the patient's consciousness level at an early stage could be a landmark to prevent further ischemic complications.

Integrative treatment of paralytic small intestine following acute cervical cord injury: A case report.

BACKGROUND: A patient developed paralysis of the small intestine following an acute traumatic hyperextension cervical spinal cord injury attributed to the ossification of the posterior longitudinal ligament (OPLL) C3-C6. The persistent ileus finally resolved utilizing Kampo medications (traditional Chinese therapy) consisting of both bukuryoin (TJ-69) and hangekobokuto (TJ-16). CASE DESCRIPTION: A 63-year-old male became acutely quadriplegic secondary to a hyperextension injury incurred during a fall. Radiographic studies confirmed mixed OPLL extending from C3-C6 resulting in marked cord compression, there was a clear spinal cord contusion. His neurological status using the American Spinal Injury Association (ASIA) Scale was Grade "A;" there were was complete motor and sensory loss below the C5 level. After a C3-C6 expansive laminoplasty, the ASIA scale improved to Grade B. However, he then developed a persistent small intestine ileus resulting in marked abdominal distention. When conventional therapies failed to resolve the problem, Kampo medicines, consisting of both bukuryoin (TJ-69) and hangekobokuto (TJ-16), were administered. The ileus improved within 2 days and fully resolved within the 1st postoperative week. CONCLUSION: The utilization of Kampo medications, consisting of both bukuryoin (TJ-69) and hangekobokuto (TJ-16), or the combined bukuryoingohangekobokuto (TJ-116) effectively resolved a postoperative paralytic small bowel ileus following a cervical laminoplasty performed in a quadriplegic patient. KEYWORDS: Acute cervical cord injury, Cervical ossification of the posterior longitudinal ligamentOPLL, Complication management, Integrative medicine, Paralytic small intestine.

Interleukin-36α as a potential biomarker for renal tubular damage induced by dietary phosphate load.

Excessive intake of phosphate has been known to induce renal tubular damage and interstitial inflammation, leading to acute kidney injury or chronic kidney disease in rodents and humans. However, sensitive and early biomarkers for phosphate-induced kidney damage remain to be identified. Our previous RNA sequencing analysis of renal gene expression identified interleukin-36α (IL-36α) as a gene significantly upregulated by dietary phosphate load in mice. To determine the time course and dose dependency of renal IL-36α expression induced by dietary phosphate load, we placed mice with or without uninephrectomy on a diet containing either 0.35%, 1.0%, 1.5%, or 2.0% inorganic phosphate for 10 days, 4 weeks, or 8 weeks and evaluated renal expression of IL-36α and other markers of tubular damage and inflammation by quantitative RT-PCR, immunoblot analysis, and immunohistochemistry. We found that IL-36α expression was induced in distal convoluted tubules and correlated with phosphate excretion per nephron. The increase in IL-36α expression was simultaneous with but more robust in amplitude than the increase in tubular damage markers such as Osteopontin and neutrophil gelatinase-associated lipocalin, preceding the increase in expression of other inflammatory cytokines, including transforming growth factor-α, interleukin-1ß, and transforming growth factor-ß1. We conclude that IL-36α serves as a marker that reflects the degree of phosphate load excreted per nephron and of associated kidney damage.

Long term outcome and adjacent disc degeneration after anterior cervical discectomy and fusion with titanium cylindrical cages.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is widely performed for the treatment of cervical spinal degenerative disease. Autogenic or allogenic bone grafts are used for interbody fusion with satisfactory long term outcomes. However, harvest of the autograft causes donor site complications and allograft is associated with low fusion rate. Threaded titanium cages (TC) have recently been introduced to cope with these disadvantages, but there is little evidence of long term results. METHODS: The long term outcome was studied after ACDF using TC. Clinical and imaging follow up was performed in 41 patients for at least 5 years (range 5-8.3 years). New computer-assisted measurement methods for radiographs are proposed. FINDINGS: ACDF with TC achieved 80% excellent or good outcome by Odom's criteria, 95% fusion rate, and few minor complications. Asymptomatic adjacent disc degeneration was detected in 50% of the patients by our measurement methods. However, symptomatic adjacent disc degeneration occurred in 5% of the patients and only 2% required additional surgery. CONCLUSIONS: These results are comparable or better than those after ACDF with autograft or allograft. ACDF with TC can achieve rigid fixation and provide good long term results.

Negative pressure pulmonary edema following foramen magnum decompression for Chiari malformation type I.

A 57-year-old obese female presented with vagal and hypoglossal nerve pareses, and magnetic resonance imaging revealed Chiari malformation type I. Standard surgical treatment for Chiari malformation type I was successfully performed. However, immediately after the patient was extubated, she developed signs of upper airway obstruction and chest radiography revealed pulmonary edema. Her ventilation was assisted by maintaining positive end-expiratory pressure at 8 cmH2O. Intravenous furosemide and hydrocortisone were administered. Her respiratory status improved 12 hours later, and she was extubated 3 days after the operation. Postextubational course was uneventful, and the patient was discharged 2 weeks after extubation. The initial neurological deficits had mostly disappeared by 10 months after the operation. This unusual case of negative pressure pulmonary edema indicates that obesity and lower cranial nerve paresis are further risk factors for pulmonary edema as a postextubational complication of surgical treatment.

History and Evolution of Laminoplasty.

Techniques of expansive laminoplasty for degenerative cervical myelopathy and ossified posterior longitudinal ligament are described, focusing on the history of the surgical procedure. Laminectomy was the only approach for posterior decompression before Japanese orthopedic surgeons introduced laminoplasty from the 1970s to the 1980s to overcome the poor outcomes of laminectomy. Recent laminoplasty techniques offer less invasive maneuvers to the posterior cervical muscle structures to reduce axial neck pain and to obtain better functional outcome, but every operation is carried out based on the unchanged initial concept. Some recent attempts to improve the surgical results are also discussed.

Flavanol-rich cocoa consumption enhances exercise-induced executive function improvements in humans.

OBJECTIVE: Aerobic exercise is known to acutely improve cognitive functions, such as executive function (EF) and memory function (MF). Additionally, consumption of flavanol-rich cocoa has been reported to acutely improve cognitive function. The aim of this study was to determine whether high cocoa flavanol (CF; HCF) consumption would enhance exercise-induced improvement in cognitive function. To test this hypothesis, we examined the combined effects of HCF consumption and moderate-intensity exercise on EF and MF during postexercise recovery. METHODS: Ten healthy young men received either an HCF (563 mg of CF) or energy-matched low CF (LCF; 38 mg of CF) beverage 70 min before exercise in a single-blind counterbalanced manner. The men then performed moderate-intensity cycling exercise at 60% of peak oxygen uptake for 30 min. The participants performed a color-word Stroop task and face-name matching task to evaluate EF and MF, respectively, during six time periods throughout the experimental session. RESULTS: EF significantly improved immediately after exercise compared with before exercise in both conditions. However, EF was higher after HCF consumption than after LCF consumption during all time periods because HCF consumption improved EF before exercise. In contrast, HCF consumption and moderate-intensity exercise did not improve MF throughout the experiment. CONCLUSION: The present findings demonstrated that HCF consumption before moderate-intensity exercise could enhance exercise-induced improvement in EF, but not in MF. Therefore, we suggest that the combination of HCF consumption and aerobic exercise may be beneficial for improving EF.

Angiographically occult spinal dural arteriovenous fistula located using selective computed tomography angiography. Case report.

Spinal dural arteriovenous fistula (DAVF) is the most common type of spinal arteriovenous malformation and may cause progressive myelopathy but is usually treatable in the early stages by direct surgery or intravascular embolization. Selective spinal angiography has been the gold standard for diagnosis, but angiographically occult DAVF is not uncommon. A 67-year-old man presented with a 2-year history of progressive paraparesis. Magnetic resonance (MR) imaging demonstrated segmental atrophy of the spinal cord and dilated coronary veins on the dorsal surface of the spinal cord. A DAVF was suspected, but repeated selective angiography failed to demonstrate the fistula. Findings from spoiled gradient echo MR imaging suggested that the draining vein flowed into the dilated venous plexus at the T-9 level. Selective computed tomography (CT) angiography of the right T-9 intercostal artery confirmed the location of the fistula. The authors successfully occluded the draining vein through surgery, and they observed that the fistula was low flow. The patient exhibited improvement in his symptoms, and postoperative MR imaging confirmed closure of the fistula. Selective CT angiography is useful in locating the draining vein of angiographically occult DAVF and therefore minimizing the extent of the surgical procedure.

Surgical management of symptomatic ossified anterior longitudinal ligament: A case report.

BACKGROUND: Ossified anterior longitudinal ligament (OALL) of the cervical spine can cause dysphagia, dyspnoea, and dysphonia, although these symptoms are rare. CASE DESCRIPTION: A 71-year-old male presented with gradually progressive dysphagia secondary to OALL. He underwent fiber optic endoscopy and lateral video fluoroscopy. The OALL extended from C4 to C7 and contributed to significant compression of the pharynx as demonstrated on plain cervical radiography, magnetic resonance (MR) imaging, and computed tomography (CT). Following microsurgical resection of the OALL, his symptoms improved. CONCLUSIONS: This study focuses on the clinical and radiographic presentation of OALL; the latter utilizing plain X-rays, MR, and CT studies. Notably, surgical resection is straightforward and allows for immediate decompression of the pharynx as long as it is truly the symptomatic problem.

Initial radiological findings utilizing titanium basket for cervical open door laminoplasty.

BACKGROUND: Cervical laminoplasty, utilizing different spacers to ''keep the door open,'' is the gold standard in Japan for treating ossification of the posterior longitudinal ligament (OPLL) and cervical spondylotic myelopathy (CSM). Here, we utilized a novel titanium ''basket'' spacer (Laminoplasty Basket: L-Basket; Ammtec, Tokyo) to perform open door cervical laminoplasty to keep the "door open" while also allowing for bony fusion across the open door. METHODS: Twenty-seven patients with/without OPLL were treated with open door laminoplasty utilizing the basket spacer. Patients were analyzed with preoperative/postoperative JOA scores, and X-rays/computed tomography (CT) at least 12 months (range, 12-19 months) postoperatively. RESULTS: Improvement from the preoperative JOA score of 10.3 points to the postoperative JOA of 14.8 points was noted 3 months postoperatively. There were no complications except one patient who had transient C5 palsy. Twelve months postoperatively, X-rays/CT documented fusion on both the open (62%) and hinge sides (90.2%); circumferential fusion was observed 59.8% of the time. CONCLUSION: This titanium "basket" spacer (Laminoplasty Basket: L-Basket; Ammtec, Tokyo) promoted bone union between the spacer and both lamina, lateral masses following cervical laminoplasty without undue complications.

Transition of a herniated lumbar disc to lumbar discal cyst: A case report.

BACKGROUND: Another rare cause of lower back pain with radiculopathy is the discal cyst. It is believed to arise from degeneration of a herniated disc, although many other theories of its origin have been proposed. Here, we report a patient with lower back pain/radiculopathy attributed originally to a herniated lumbar disc, which transformed within 6 months into a discal cyst. CASE DESCRIPTION: A 42-year-old male had a magnetic resonance (MR) documented herniated lumbar disc at the L4-5 level. It was managed conservatively for 6 months, after which symptoms recurred and progressed. The follow-up MR study revealed a discal cyst at the L4-5 without residual herniated disc. Of interest, the cyst communicated with the L4-5 intervertebral disc, which was herniated under the posterior longitudinal ligament and the disc space. During surgery, the cyst was completely removed, and his symptoms/signs resolved. CONCLUSION: A discal cyst develops as pathological sequelae of a degenerated herniated disc. Although rare, these lesions must be considered among the differential diagnoses in young patients with radicular back pain. MR study clearly documents these lesions, and surgical excision of the cyst is the treatment of choice.

[Four cases of spontaneous spinal epidural hematoma].

Spontaneous spinal epidural hematoma (SSEH) is a rare clinical entity. Although approximately 500 cases have been reported, controversy exists concerning timing of the treatment and the validity of decompression surgery. We recently encountered four cases of SSEH. Evacuation of the hematoma was carried out in two patients with severe or persistent neurological deficits. Other two patients were treated conservatively because of the rapid resolution of the symptoms. All four patients improved after the treatment; three patients fully recovered and one patient required rehabilitation for moderate quadriparesis. Many previous reports recommended decompression surgery within 48 hours after the onset, however, one patient in our series fully recovered after surgery 4 days after the onset. We reviewed 183 operative cases of SSEH with incomplete neurological deficits in the literature and found that 93% of the patients who underwent surgery more than 48 hours after symptom onset showed good neurological recovery. Conservative treatment should be undertaken for rapidly improving patients, but surgical intervention should be considered in symptomatic patients regardless of the time from the onset.

Simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery aneurysms.

OBJECT: The authors of this study evaluated the efficacy of simultaneous microscopic and endoscopic monitoring during surgery for internal carotid artery (ICA) aneurysms. METHODS: The endoscopic technique was applied during microsurgery in 11 patients with 13 aneurysms. Nine of these lesions were located on the posterior communicating artery (PCoA), three in the paraclinoid region, and one on the anterior choroidal artery (AChA). Eight patients had unruptured aneurysms and three had ruptured aneurysms. The endoscope was introduced after first exposing the aneurysm through the microscope and was gripped firmly by an airlocked holding arm fitted with a steering system throughout the entire surgery, including dissection of the perforating arteries and application of the aneurysm clips. Regarding paraclinoid aneurysms, clips were applied through direct visualization of the ophthalmic artery and the proximal neck. In a case involving a superior hypophyseal artery aneurysm in the paraclinoid segment, a ring clip was applied without removing the bone structure around the optic canal. In all aneurysms of the PCoA and the AChA, perforating arteries behind the lesion were identified and dissected using endoscopic control. The aneurysm clip was applied in the best position in a single attempt in 10 of 11 patients. There was no surgical complication related to the endoscopic procedures. CONCLUSIONS: Simultaneous monitoring with the microscope and endoscope is extremely useful in applying clips to ICA aneurysms. This combined method allows for direct dissection of the aneurysm, perforating vessels, and the main trunk in an area not visible through the microscope's eyepiece and promises better surgical results.

Width-controlled sub-nanometer graphene nanoribbon films synthesized by radical-polymerized chemical vapor deposition.

Radical-polymerized chemical vapor deposition, a new bottom-up method, was developed to produce graphene nanoribbons (GNRs) efficiently, despite the use of extremely low vacuum. Using this technique, a systematic synthesis of a multilayered high-density array of width-controlled sub-1 nm GNRs on a metal surface, with width-dependent band gap, is made possible. GNR films transferred onto insulating substrates behave as an excellent photoconductor.

Percutaneous endoscopic lumbar discectomy - early clinical experience.

We report our early clinical experience with percutaneous endoscopic lumbar discectomy (PELD) for herniated nucleus pulposus (HNP) in the lumbar spine. We introduced PELD to our clinical practice in June 2009. A total of 311 patients with degenerative lumbar spine disease were treated in our hospital up to August 2011. Thirty-seven patients with lumbar HNP were treated by PELD. PELD was carried out under local anesthesia, and the endoscope was continuously irrigated with saline. Twenty-eight patients were treated through the transforaminal approach, 5 were treated through the interlaminar approach, and 4 were treated through the extraforaminal approach. Surgery was discontinued due to uncontrollable intraoperative pain or anatomical inaccessibility in one case of the interlaminar approach and 2 cases of the extraforaminal approach. In the other 34 patients, the elapsed time of surgery was 34 to 103 minutes (mean 62.4 minutes). Extracorporeal blood loss was insignificant. Immediate symptom relief was achieved in all patients, and postoperative magnetic resonance imaging revealed sufficient removal of the HNP. The length of the postoperative hospital stay was 1 or 2 days in all patients. The surgical method of PELD is completely different from percutaneous nucleotomy, and the aim is to directly remove the HNP with minimum damage to the musculoskeletal structure. Although this study is based on our early clinical outcomes, PELD seemed to be a promising minimally invasive surgery for HNP in the lumbar spine.