A motif in the 5'untranslated region of messenger RNAs regulates protein synthesis in a S6 kinase-dependent manner.

The 5' untranslated regions (UTRs) in messenger RNAs (mRNAs) play an important role in the regulation of protein synthesis. We had previously identified a group of mRNAs that includes human semaphorin 7A (SEMA7A) whose translation is upregulated by the Erk/p90S6K pathway in human eosinophils, with a potential negative impact in asthma and airway inflammation. In the current study, we aimed to find a common 5'UTR regulatory cis-element, and determine its impact on protein synthesis. We identified a common and conserved 5'UTR motif GGCTG-[(C/G)T(C/G)]n-GCC that was present in this group of mRNAs. Mutations of the first two GG bases in this motif in SEMA7A 5'UTR led to a complete loss of S6K activity dependence for maximal translation. In conclusion, the newly identified 5'UTR motif present in SEMA7A has a critical role in regulating S6K-dependent protein synthesis.

Distribution, Effect, and Control of Exotic Plants in Republic of Korea.

This study was carried out to clarify the spatial distribution of exotic plants at national, regional, and local levels, as well as their ecological impacts, and to prepare a strategy to reduce the impacts in Republic of Korea. This study was attempted at the national, regional, and local levels throughout Republic of Korea. Compositae occupied the highest percentage among invading exotic plants in Republic of Korea. A review of the biological attributes of exotic plants based on the dormancy form, longevity, disseminule form, growth form, and radicoid form showed that therophytes, annual plants, plants that disperse seeds by gravity (D4), erect form (E), and nonclonal growth form (R5) occupied the highest proportion. At the national level, the spatial distribution of exotic plants tended to depend on topographic conditions such as elevation and slope degree, and to increase around urbanized areas, agricultural fields, and coastal areas. The habitat types that exotic plants established were similar in their native habitat and in Korea, where they invaded. They preferred disturbed land such as roadsides, bare ground, agricultural fields, and so on. The spatial distribution of vegetation types dominated by exotic plants was restricted in the lowland. The proportion of the exotic/native plants tended to proportionate reversely to the vegetation type richness (the number of vegetation types); that is, the ecological diversity. The proportion of the exotic plants was higher in artificial plantations, vegetation due to disturbance, and vegetation established on lower slopes compared with upper slopes. Even at the local level, the exotic plants appeared abundantly in the introduced vegetation, while they were rare in the native ones. In the vegetation infected by exotic species, not only the species composition changed significantly, but the species diversity also decreased. Restorative treatment by introducing mantle vegetation around the hiking trail inhibited the establishment of exotic plants. Further, the restoration practice recovered the similarity of the species composition compared to the reference vegetation and increased the species diversity.

Laminectomy with instrumented fusion vs. laminoplasty in the surgical treatment of cervical ossification of the posterior longitudinal ligament: A multicenter retrospective study.

Laminectomy with instrumented fusion (LF) has demonstrated better prevention of ossification of posterior longitudinal ligament (OPLL) growth compared to laminoplasty (LP). There remains uncertainty, however, as to which surgical approach is more beneficial with respect to clinical outcomes and complications. We retrospectively reviewed 273 cervical OPLL patients of more than 3 levels, from the two institutions' databases, who underwent LF or LP between January 1998 and January 2016. Each 273 patient (85 with LF, 188 with LP) was assessed for postoperative neurologic and radiologic outcomes, complications and reoperations. The mean length of follow-up was 40.11 months. There were baseline differences between cohorts. Overall, postoperative JOA recovery rate at last follow up was significantly better in the LP group with similar improvement in visual analog neck score. Postoperative C2-7 Cobb angle was decreased compared to baseline for both LF and LP cohorts, but there was no significant difference between groups. Complications occurred in 19 (22.35%) LF patients, and 11 (5.85%) LP patients, with higher incidence of C5 palsy and instrumentation failure in the LF group. Four LF patients (4.71%) and five LP patients (2.66%) underwent reoperation during the follow up period.

Clinical and radiological outcomes of multilevel cervical laminoplasty versus three-level anterior cervical discectomy and fusion in patients with cervical spondylotic myelopathy.

BACKGROUND: Cervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord impairment in elderly patients. However, a consensus has yet to be reached on the ideal method of surgical intervention. In this study, we investigated serial changes of radiological findings after three-level anterior cervical discectomy and fusion (ACDF) and multilevel laminoplasty and attempted to identify the radiological parameters affecting long-term clinical outcomes in CSM. METHODS: Of the 152 patients with multilevel CSM treated with three-level ACDF and multilevel laminoplasty, 42 had complete radiological parameters both before and 2 years after surgery (three-level ACDF, 22 patients; multilevel laminoplasty, 20 patients). Radiological parameters included spinal cord signal intensity (SI) changes on magnetic resonance imaging (MRI). Clinical outcomes including the Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), Oswestry disability index (ODI), and 36-Item Short Form Health Survey score were measured. RESULTS: The ACDF group showed significant restoration of segmental lordosis postoperatively (preoperatively: 2.21°, 6 months: 8.37°, P=0.026), and segmental and cervical range of motion (ROM) was markedly reduced and well maintained until the final follow-up (preoperatively: 25.48°, 24 months: 4.35°, P<0.001; preoperatively: 41.71°, 24 months: 20.18°, P<0.001). The recovery rates of the JOA score were 42.85% and 57.40% in the ACDF and laminoplasty groups, respectively, although this difference was not statistically significant. Multivariate regression analysis demonstrated that signal change on MRI significantly affected the recovery rate (P=0.003). The visual analog scale (VAS) score and NDI decreased considerably only in the laminoplasty group, and device complications were confirmed only in the ACDF group (incidence rate =36.5%). CONCLUSIONS: Multilevel laminoplasty showed better radiological and similar clinical outcomes. ACDF had more surgical complications. Spinal cord SI change on preoperative MRI was the independent risk factor for poor clinical outcomes. We recommend laminoplasty instead of three-level ACDF to treat multilevel CSM.

Analysis of Risk Factors Associated with Hospital Readmission Within 360 Days After Degenerative Lumbar Spine Surgery in Elderly Patients.

OBJECTIVE: There is a paucity of studies on readmission rates in elderly patients over a period of 360 days after spinal surgery. METHODS: We identified 1248 patients older than 70 years who underwent degenerative lumbar spinal surgery from November 2005 to April 2015. We reviewed the patients who were readmitted within 360 days and compared them by univariate and multivariate analysis with the nonreadmitted patients for each period of 0-30, 30-90, 90-180, and 180-360 days postoperatively to determine risk factors for hospital readmission. RESULTS: A total of 1248 patients (733 female, 58.7%) were enrolled in the study. The number of readmitted patients was 37 (2.96%), 94 (7.53%), 145 (11.62%), 182 (14.58%), and 213 (17.07%) at 30, 90, 180, 270, and 360 days, respectively. Surgical site-related problems decreased gradually in the first 0-90 days and slightly increased after then. Non-surgical site-related problems gradually increased with time. Logistic multiple regression analysis showed that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low alanine aminotransferase level, high body mass index, and high platelet level were risk factors for readmission. CONCLUSIONS: We found that electrocardiographic abnormalities, male sex, low hemoglobin levels, asthma, heart disease, intensive care unit admission, low aspartate aminotransferase level, high body mass index, and high platelet level were risk factors for readmission. As the postoperative observational period became longer, the reasons for readmission tended to be more related to non-surgical site-related problems than to surgical-related problems.

Pharmacological target therapy of neuropathic pain and patient-reported outcomes in patients with chronic low back pain in Korea: Results from the NLBP Outcomes Research.

A number of studies have demonstrated an association of neuropathic pain and chronic low back pain (CLBP), but the outcome difference in each medical management is poorly understood. This study is aimed to investigate treatment patterns of neuropathic pain in CLBP patients and to explore patient-reported outcomes (PROs) including quality of life (QoL) and functional disability by treatment patterns.Data were extracted from the neuropathic low back pain (NLBP) outcomes research. It was a multicenter and cross-sectional study in which 1200 patients were enrolled at 27 general hospitals, from 2014 to 2015. Of total, 478 patients classified as neuropathic pain were used for this subgroup analysis. The patients were divided into 2 groups according to treatment patterns (with vs. without the targeted therapy [TT] of neuropathic pain). Demographic and clinical features were collected by chart reviews and PROs were measured by patient's survey. QoL was assessed by EuroQoL 5-dimension (EQ-5D) questionnaire. Functional disability was measured by the Quebec Back Pain Disability Scale (QBPDS). Multiple linear regression analyses were conducted to compare the PROs between TT group and non-targeted therapy (nTT) group.Among the NLBP patients (mean age 63years, female 62%), EQ-5D index, EuroQoL-Visual Analog Scale (EQ-VAS), and QBPDS Scores (mean ±â€Šstandard deviation) were 0.40 ±â€Š0.28, 54.98 ±â€Š19.98, and 46.03 ±â€Š21.24, respectively. Only 142 (29.7%) patients had pharmacological TT of neuropathic pain. Univariate analyses revealed no significant mean differences between TT group and nTT group in the EQ-5D index (0.41 ±â€Š0.27 and 0.39 ±â€Š0.28), EQ-VAS (56.43 ±â€Š18.17 and 54.37 ±â€Š20.69), and QBPDS (45.31 ±â€Š21.32 and 46.31 ±â€Š21.24). After adjustment with covariates, TT group had higher scores of EQ-5D index (ß = 0.07; P < 0.01) and EQ-VAS (ß = 4.59; P < 0.05) than the nTT group. The TT group's QBPDS score was lower than the nTT group, although its statistical significance still has not been reached (ß = -4.13; P = 0.07).We found that considerable proportion of the NLBP patients remains untreated or undertreated. Although TT group had significantly better QoL than nTT group, only 29.7% of NLBP patients had pharmacological TT. Therefore, clinicians should consider using TT for better QoL of neuropathic pain patients.

Effect of posterior instrumented fusion on three-dimensional volumetric growth of cervical ossification of the posterior longitudinal ligament: a multiple regression analysis.

BACKGROUND CONTEXT: Despite the fact that ossification of posterior longitudinal ligament (OPLL) is a three-dimensional disease, conventional studies have focused mainly on a two-dimensional measurement, and it is difficult to accurately determine the volume of OPLL growth and analyze the factors affecting OPLL growth after posterior decompression (laminoplasty or laminectomy and fusion). PURPOSE: The present study aimed to investigate the factors affecting OPLL volume growth using a three-dimensional measurement. STUDY DESIGN/SETTING: This was a retrospective case study. PATIENT SAMPLE: Eighty-three patients with cervical OPLL who were diagnosed as having multilevel cervical OPLL of more than three levels on cervical computed tomography (CT) scans were retrospectively reviewed from June 1, 1998, to December 31, 2015. OUTCOME MEASURES: The OPLL volume from the C1 vertebrae to the C7 vertebrae was measured on preoperative and the most recent follow-up CT scans. METHODS: Eighty-three patients were retrospectively examined for age, gender, body mass index, hypertension, diabetes, type of OPLL, surgical method, preoperative cervical curvature, and preoperative and postoperative cervical range of motion. Preoperative cervical CT and the most recent follow-up cervical CT scans were converted to Digital Imaging and Communications in Medicine data, and the OPLL volume was three-dimensionally measured using the Mimics program (Materialise, Leuven, Belgium). The OPLL volume growth was analyzed using univariate and multivariate analyses. RESULTS: The average follow-up period was 32.36 (±23.39) months. Patients' mean age was 54.92 (±8.21) years. In univariate analysis, younger age (p=.037) and laminoplasty (p=.012) were significantly associated with a higher mean annual growth rate of OPLL (%/y). In multivariate analysis, only laminoplasty (p=.027) was significantly associated with a higher mean annual growth rate of OPLL (%/y). The mean annual growth rate of OPLL was about seven times faster with laminoplasty (8.00±13.06%/y) than with laminectomy and fusion (1.16±9.23%/y). CONCLUSIONS: Posterior instrumented fusion has the effect of reducing OPLL growth rate compared with motion-preserving laminoplasty. Patients' age and the surgical method need to be considered in surgically managing the multilevel OPLL.

Prevalence of Neuropathic Pain and Patient-Reported Outcomes in Korean Adults with Chronic Low Back Pain Resulting from Neuropathic Low Back Pain.

STUDY DESIGN: A noninterventional, multicenter, cross-sectional study. PURPOSE: We investigated the prevalence of neuropathic pain (NP) and patient-reported outcomes (PROs) of the quality of life (QoL) and functional disability in Korean adults with chronic low back pain (CLBP). OVERVIEW OF LITERATURE: Among patients with CLBP, 20%-55% had NP. METHODS: Patients older than 20 years with CLBP lasting for longer than three months, with a visual analog scale (VAS) pain score higher than four, and with pain medications being used for at least four weeks before enrollment were recruited from 27 general hospitals between December 2014 and May 2015. Medical chart reviews were performed to collect demographic/clinical features and diagnosis of NP (douleur neuropathique 4, DN4). The QoL (EuroQoL 5-dimension, EQ-5D; EQ-VAS) and functional disability (Quebec Back Pain Disability Scale, QBPDS) were determined through patient surveys. Multiple linear regression analyses were performed to compare PROs between the NP (DN4≥4) and non-NP (DN4<4) groups. RESULTS: A total of 1,200 patients (females: 65.7%; mean age: 63.4±13.0 years) were enrolled. The mean scores of EQ-5D, EQ-VAS, and QBPDS were 0.5±0.3, 55.7±19.4, and 40.4±21.1, respectively. Among all patients, 492 (41.0%; 95% confidence interval, 38.2%-43.8%) suffered from NP. The prevalence of NP was higher in male patients (46.8%; p<0.01), in patients who had pain based on radiological and neurological findings (59.0%; p<0.01), and in patients who had severe pain (49.0%; p<0.01). There were significant mean differences in EQ-5D (NP group vs. non-NP group: 0.4±0.3 vs. 0.5±0.3; p<0.01) and QBPDS (NP group vs. non-NP group: 45.8±21.2 vs. 36.3±20.2; p<0.01) scores. In the multiple linear regression, patients with NP showed lower EQ-5D (ß=-0.1; p<0.01) and higher QBPDS (ß=7.0; p<0.01) scores than those without NP. CONCLUSIONS: NP was highly prevalent in Korean patients with CLBP. Patients with CLBP having NP had a lower QoL and more severe dysfunction than those without NP. To enhance the QoL and functional status of patients with CLBP, this study highlights the importance of appropriately diagnosing and treating NP.

Effectiveness of Osteoporosis Drug in Postmenopausal Women with Spinal Compression Fracture: Combined Consecutive Therapy of Teriparatide and Raloxifene versus Bisphosphonate Single.

OBJECTIVE: Bisphosphonate, a typical bone resorption inhibitor, is an important first-line drug for treating osteoporosis. Recent studies show a novel paradigm in stimulating bone formation. Teriparatide, which is composed of recombinant human parathyroid hormone, stimulates osteoblasts and induces bone regeneration. Bone mineral density (BMD) that was used before and after the treatment with anti-osteoporosis drug was compared for the effectiveness in therapy between a combination of teriparatide and selective estrogen receptor modulator (SERM), and bisphosphonate. METHODS: We retrospectively reviewed the outcomes of 85 postmenopausal women who were concurrently diagnosed with osteoporosis and spinal compression fracture between November 2008 and January 2015. The targeted group were treated with teriparatide and SERM (TS group, n=26) and bisphosphonate (B group, n=59). RESULTS: In both groups, BMD of femur neck was not improved after the medication. In the TS group, on the other hand the BMD and T-score of lumbar spine has significantly improved. BMD ratio of lumbar spine was prominently higher than those of TS group. CONCLUSION: The combination therapy of teriparatide and SERM was very effective in treating the lumbar spine, compared to that of bisphosphonate. Although the period of teriparatide treatment has been relatively short, the preventive effects of compression fracture were considerable. Thus, combination therapy of teriparatide and SERM is highly recommended for patients who are concerned with spinal compression fracture from osteoporosis.

Compression Angle of Ossification of the Posterior Longitudinal Ligament and Its Clinical Significance in Cervical Myelopathy.

OBJECTIVES: The correction of clinical and radiologic abnormalities in patients with symptomatic ossification of the posterior longitudinal ligament (OPLL) is the current mainstay of treatment. This study aimed to identify radiographic predictors of severity of myelopathy in patients with symptomatic OPLL. METHODS: Fifty patients with symptomatic cervical OPLL were enrolled. Based on Japanese Orthopedic Association (JOA) scores, patients were divided into either the mild myelopathy (n=31) or severe myelopathy (n=19) group. All subjects underwent preoperative plain cervical roentgenogram, computed tomography (CT), and MR imaging (MRI). Radiological parameters (C2-7 sagittal vertical axis, SVA; C2-7 Cobb angle; C2-7 range of motion, ROM; OPLL occupying ratio; and compression angle) were compared. Compression angle of OPLL was defined as the angle between the cranial and caudal surfaces of OPLL at the maximum level of cord compression. RESULTS: The occupying ratio of the spinal canal, C2-7 Cobb angle, C2-7 SVA, types of OPLL, and C2-7 ROM of the cervical spine were not statistically different between the two groups. However, the OPLL compression angle was significantly greater (p=0.003) in the severe myelopathy group than in the mild myelopathy group and was inversely correlated with JOA score (r=-0.533, p<0.01). Furthermore, multivariate regression analysis demonstrated that the compression angle (B=-0.069, p<0.001) was significantly associated with JOA scores (R=0.647, p<0.005). CONCLUSION: Higher compression angles of OPLL have deleterious effects on the spinal cord and decrease preoperative JOA scores.

Clinical Characteristics and Surgical Outcome of Revision Surgery in Patients with Cervical Ossification of the Posterior Longitudinal Ligament.

OBJECTIVE: To investigate the clinical characteristics and surgical outcome of revision surgery after first surgical decompression of cervical ossification of posterior longitudinal ligament. METHODS: A retrospective analysis was performed of 913 patients who underwent surgical decompression of cervical ossification of posterior longitudinal ligament from 1998 to 2012. Of these patients, 35 underwent revision surgery. Neurologic and surgical outcomes, radiologic findings, surgical procedures, and complications were evaluated. Indications for revision surgery were compared between early (≤24 months after the first surgery) and delayed (>24 months after the first surgery) revision surgery. RESULTS: There was a higher prevalence of male patients with revision surgery (89%) compared with patients without revision surgery (71.2%, P = 0.033). Preoperative Japanese Orthopaedic Association score was significantly lower in patients with revision surgery (11.5 vs. 12.7, P < 0.01). Visual analog scale score for neck pain was improved both without revision surgery (from 3.0 to 2.1, P < 0.001) and with revision surgery (from 3.0 to 2.2, P < 0.001) patients. Symptomatic residual stenosis was a more frequent cause of revision surgery in early revision surgery than in delayed revision surgery (75% vs. 25%, P < 0.001). In delayed revision surgery, growth of ossification of posterior longitudinal ligament (50%) was the primary cause of revision surgery. CONCLUSIONS: Clinical outcomes (Japanese Orthopaedic Association and visual analog scale scores) of revision surgery are similar to the outcomes of patients who did not require revision surgery. Residual stenosis after the index surgery is the most common indication for early revision surgery. To avoid early revision surgery, surgeons should carefully consider achieving circumferential decompression of the spinal canal during initial surgery.

Correlation between cervical spine sagittal alignment and clinical outcome after cervical laminoplasty for ossification of the posterior longitudinal ligament.

OBJECTIVE: The goal of this study was to determine the relationship between cervical spine sagittal alignment and clinical outcomes after cervical laminoplasty in patients with ossification of the posterior longitudinal ligament (OPLL). METHODS: Fifty consecutive patients who underwent a cervical laminoplasty for OPLL between January 2012 and January 2013 and who were followed up for at least 1 year were analyzed in this study. Standing plain radiographs of the cervical spine, CT (midsagittal view), and MRI (T2-weighted sagittal view) were obtained (anteroposterior, lateral, flexion, and extension) pre- and postoperatively. Cervical spine alignment was assessed with the following 3 parameters: the C2-7 Cobb angle, C2-7 sagittal vertical axis (SVA), and T-1 slope minus C2-7 Cobb angle. The change in cervical sagittal alignment was defined as the difference between the post- and preoperative C2-7 Cobb angles, C2-7 SVAs, and T-1 slope minus C2-7 Cobb angles. Outcome assessments (visual analog scale [VAS], Oswestry Neck Disability Index [NDI], 36-Item Short-Form Health Survey [SF-36], and Japanese Orthopaedic Association [JOA] scores) were obtained in all patients pre- and postoperatively. RESULTS: The average patient age was 56.3 years (range 38-72 years). There were 34 male patients and 16 female patients. Cervical laminoplasty for OPLL helped alleviate radiculomyelopathy. Compared with the preoperative scores, improvement was seen in postoperative VAS and JOA scores. After laminoplasty, 35 patients had kyphotic changes, and 15 had lordotic changes. However, cervical sagittal alignment after laminoplasty was not significantly associated with clinical outcomes in terms of postoperative improvement of the JOA score (C2-7 Cobb angle: p = 0.633; C2-7 SVA: p = 0.817; T-1 slope minus C2-7 lordosis: p = 0.554), the SF-36 score (C2-7 Cobb angle: p = 0.554; C2-7 SVA: p = 0.793; T-1 slope minus C2-7 lordosis: p = 0.829), the VAS neck score (C2-7 Cobb angle: p = 0.263; C2-7 SVA: p = 0.716; T-1 slope minus C2-7 lordosis: p = 0.497), or the NDI score (C2-7 Cobb angle: p = 0.568; C2-7 SVA: p = 0.279; T-1 slope minus C2-7 lordosis: p = 0.966). Similarly, the change in cervical sagittal alignment was not related to the JOA (p = 0.604), SF-36 (p = 0.308), VAS neck (p = 0.832), or NDI (p = 0.608) scores. CONCLUSIONS: Cervical laminoplasty for OPLL improved radiculomyelopathy. Cervical laminoplasty increased the probability of cervical kyphotic alignment. However, cervical sagittal alignment and clinical outcomes were not clearly related.

Paradoxical Radiographic Changes of Coflex Interspinous Device with Minimum 2-Year Follow-Up in Lumbar Spinal Stenosis.

OBJECTIVES: Studies have yet to investigate long-term radiologic changes in lumbar spinal stenosis patients treated with interspinous device (Coflex). This study aimed to evaluate which radiologic parameters change significantly after surgery with Coflex and identify which parameter most affects the radiologic outcome. METHODS: Of 101 patients with lumbar spinal stenosis treated by Coflex insertion on L4-5, the radiologic parameters of 30 patients were measured before and at least 2 years after surgery. On the basis of the development of bony erosion around Coflex, patients were divided into the erosion group (n = 14) or the nonerosion group (n = 16). RESULTS: The mean anterior disc height (ADH) and range of motion (ROM) were significantly decreased after surgery (15.161 mm vs. 13.788 mm and 9.63° vs. 7.13°). The erosion group showed substantially higher values in preoperative ADH, postoperative posterior disc height (PDH), and intervertebral foramen height (6.52 mm vs. 8.05 mm; 5.80 mm vs. 8.03 mm; 19.20 mm vs. 21.06 mm). Postoperative ROM and ROM ratio were higher in the erosion group (5.95° vs. 8.47° and 0.659 vs. 0.938). However, only ADH showed a significant change in the erosion group after surgery (15.86 mm vs. 14.29 mm). On the contrary, ADH and PDH, as well as ROM, were significantly decreased in the nonerosion group (14.55 mm vs. 13.34 mm; 6.52 mm vs. 5.82 mm; 9.46° vs. 5.95°). CONCLUSION: The preoperative state including relatively higher ADH, PDH, and larger ROM could induce erosion. The long-term preservation of disc height and ROM may also induce erosion. That reduction of most radiologic parameters seems to be natural after surgery, and insufficient reduction of disc height and ROM may induce adverse effects, which can increase the possibility of spinous process fracture or device malposition.

Analysis of the Microbial Community in an Acidic Hollow-Fiber Membrane Biofilm Reactor (Hf-MBfR) Used for the Biological Conversion of Carbon Dioxide to Methane.

Hydrogenotrophic methanogens can use gaseous substrates, such as H2 and CO2, in CH4 production. H2 gas is used to reduce CO2. We have successfully operated a hollow-fiber membrane biofilm reactor (Hf-MBfR) for stable and continuous CH4 production from CO2 and H2. CO2 and H2 were diffused into the culture medium through the membrane without bubble formation in the Hf-MBfR, which was operated at pH 4.5-5.5 over 70 days. Focusing on the presence of hydrogenotrophic methanogens, we analyzed the structure of the microbial community in the reactor. Denaturing gradient gel electrophoresis (DGGE) was conducted with bacterial and archaeal 16S rDNA primers. Real-time qPCR was used to track changes in the community composition of methanogens over the course of operation. Finally, the microbial community and its diversity at the time of maximum CH4 production were analyzed by pyrosequencing methods. Genus Methanobacterium, related to hydrogenotrophic methanogens, dominated the microbial community, but acetate consumption by bacteria, such as unclassified Clostridium sp., restricted the development of acetoclastic methanogens in the acidic CH4 production process. The results show that acidic operation of a CH4 production reactor without any pH adjustment inhibited acetogenic growth and enriched the hydrogenotrophic methanogens, decreasing the growth of acetoclastic methanogens.

Healthcare Utilization Monitoring System in Korea.

OBJECTIVES: It is important to monitor the healthcare utilization of patients at the national level to make evidence-based policy decisions and manage the nation's healthcare sector. The Health Insurance Review & Assessment Service (HIRA) has run a Healthcare Utilization Monitoring System (HUMS) since 2008. The objective of this paper is to introduce HIRA's HUMS. METHODS: This study described the HUMS's system structure, capacity, functionalities, and output formats run by HIRA in the Republic of Korea. Regarding output formats, this study extracted diabetes related health insurance claims through the HUMS from August 1, 2014 to May 31, 2015. RESULTS: The HUMS has kept records of health insurance claim data for 4 years. It has a 14-terabyte hardware capacity and employs several easy-to-use programs for maintenance of the system, such as MSTR, SAS, etc. Regarding functionalities, users should input diseases codes, target periods, facility types, and types of attributes, such as the number of healthcare utilizations or healthcare costs. It also has a functionality to predict healthcare utilization and costs. When this study extracted diabetes related data, it was found that the trend of healthcare costs for the treatment of diabetes and the number of patients with diabetes were increasing. CONCLUSIONS: HIRA's HUMS works well to monitor healthcare utilization of patients at the national level. The HUMS has a high-capacity hardware infrastructure and several operational programs that allows easy access to summaries as well as details to identify contributing factors for abnormality, but it has a limitation in that there is often a time lag between the provision of healthcare to patients and the filing of health claims.

Usefulness of 3-dimensional Measurement of Ossification of the Posterior Longitudinal Ligament (OPLL) in Patients With OPLL-induced Myelopathy.

STUDY DESIGN: Retrospective study. OBJECTIVE: To evaluate the usefulness of 3-dimensional (3D) measurement of ossification of the posterior longitudinal ligament (OPLL), and identify the reliability of a novel 3D method of measurement. SUMMARY OF BACKGROUND DATA: OPLL is not a 2-dimensional (2D) disease, but rather a 3D disease. Therefore, conventional measurement of parameters using radiography may not be suitable for evaluating OPLL. However, there is no study that investigated the correlation between 3D parameters of OPLL and clinical outcomes. METHODS: 50 patients (40 males and 10 females; mean age 57.2 yr) with symptomatic OPLL were enrolled. Neurological and clinical outcome scales were measured using the Japanese Orthopedic Association (JOA) score, visual analogue scale, short-form health survey (SF-36) and neck disability index. A 3D model was reconstructed with digital imaging and communications in medicine files from axial computed tomographic images using software (MIMICS; Materialise, Leuven, Belgium) to obtain the following parameters: 3D volume of OPLL, 3D volume of the spinal canal (confined to the vertebral level involving OPLL), spinal canal diameter, thickness of OPLL, and length of OPLL. All patients were divided into 2 different groups, the mild myelopathy group (JOA score ≥18, n = 11) and the severe myelopathy group (JOA score ≤17, n = 23). RESULTS: The 3D OPLL volume did not correlate with clinical outcomes (r =-0.275, P = 0.116). 3D OPLL ratio and OPLL thickness had a significant negative relationship with JOA score (r =-0.502, P < 0.005 and r =-0.437, P < 0.05, respectively). In particular, 3D OPLL ratio was an independent risk factor for increased severity of myelopathy (B =-29.71, P < 0.05). The mild myelopathy group showed lower 3D OPLL ratio than the severe myelopathy group (0.092 vs. 0.148, P < 0.05). CONCLUSION: 3D method of measurement is superior to the conventional method in terms of evaluating the clinical state of symptomatic patients with OPLL. Higher 3D OPLL ratio has an adverse effect on the spinal cord. LEVEL OF EVIDENCE: 3.

Surgical outcome and prognostic factors of anterior decompression and fusion for cervical compressive myelopathy due to ossification of the posterior longitudinal ligament.

BACKGROUND CONTEXT: Anterior decompression and fusion (ADF) for ossification of the posterior longitudinal ligament (OPLL) is technically demanding and associated with complications. Although various factors affecting clinical outcome have been investigated in posterior decompression, prognostic factors of ADF remain unclear. PURPOSE: The purpose of the study was to identify surgical outcome and prognostic factors of ADF for cervical myelopathy due to OPLL. STUDY DESIGN: This was a retrospective case study. PATIENT SAMPLE: Between 2005 and 2012, 913 patients underwent decompression surgery for cervical OPLL at our institution. Among them, 131 who underwent ADF and 221 who underwent laminoplasty were enrolled. Inclusion criteria were (1) diagnosis of OPLL; (2) cervical compressive myelopathy; and (3) no trauma, infection, tumor, or previous surgery. We excluded 60 patients with ADF and 157 patients with laminoplasty owing to inadequate follow-up or absence of preoperative myelopathy. Finally, 71 patients with ADF and 64 patients with laminoplasty were enrolled in this study (mean follow-up, 48 vs 41 months). OUTCOME MEASURES: Neurologic assessment was conducted using the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy. Rate of neurologic improvement was calculated by comparing preoperative and postoperative JOA scores. METHODS: We investigated the effects of such variables as age, gender, body mass index (BMI), presence of diabetes mellitus (DM), smoking history, type of OPLL, shape of the ossified lesion, occupying ratio of OPLL, presence of intramedullary increased signal intensity (ISI) on magnetic resonance imaging (MRI), and sagittal alignment of the cervical spine on surgical outcome. Severity of ISI was classified into three groups based on T2-weighted sagittal MRI as follows: Grade 0, none; Grade 1, ISI limited to one disc level; or Grade 2, ISI beyond one disc level. This work was supported by the 2013 Korea Health Technology R&D Project of the Ministry of Health and Welfare of the Republic of Korea (A120254). RESULTS: In patients with an occupying ratio ≥60% or with presence of ISI on MRI, ADF yielded better surgical outcome than laminoplasty. A higher ISI grade (B=-28.5, p=.000) and a higher occupying ratio (B=0.88, p=.04) were significantly associated with a lower recovery rate (R=0.56, p=.006). Older age also was associated with a lower recovery rate. Gender, BMI, presence of DM, smoking history, type of OPLL, shape of the ossified lesion, and cervical alignment were not associated with recovery rate. CONCLUSION: Anterior decompression and fusion has favorable outcome in patients with an occupying ratio ≥60% or with presence of ISI on MRI. Presence of higher ISI grade, higher occupying ratio, and older age were associated with a poor long-term surgical prognosis. Therefore, evaluating ISI and occupying ratio on preoperative MRI is important for selecting the appropriate surgical approach and for predicting clinical outcome after surgery for cervical compressive myelopathy due to OPLL.

The fate of heterotopic ossification associated with cervical artificial disc replacement.

STUDY DESIGN: This is a retrospective study designed to observe the progressive appearance of heterotopic ossification (HO) after cervical artificial disc replacement (ADR). OBJECTIVE: To investigate the development and progressive appearance of HO at cervical ADR sites. SUMMARY OF BACKGROUND DATA: HO is defined as the formation of bone outside the skeletal system. The reported HO occurrence rate in cervical ADR is high and varied. However, the long-term outcome of HO has not been investigated by longitudinal observation. METHODS: Sixty-seven consecutive patients undergoing cervical ADR with complete radiological data were selected for this study. Cervical lateral radiographs and computed tomographic scans were obtained during the first and second studies and compared to identify any transitions in HO. The change in the HO occurrence rate, distribution, and grade of HO were investigated at 2 follow-up time points (18.6 and 36.9 mo postsurgery). To compare the amount of progression between participants' HO rates, the relative increase rate was calculated. RESULTS: HO showed a progressive pattern. The grade of HO was redistributed toward a higher grade in the second study. The number of patients with HO had increased from 31 (46.3%) to 43 (64.2%) of 67 patients at the final follow-up with statistically significant difference (P = 0.037). Twenty-six patients (39.4%) had progressed toward a higher HO grade, but 41 patients (60.6%) showed no change in HO grade. The overall RI rate and the weighted RI rate were 39.4% and 48.7%, respectively. CONCLUSION: This study found that HO has a progressive appearance and determined that HO is not a static but rather a dynamic phenomenon with progressive pattern. Future elucidation of the environmental factors affecting HO, including genetic or proteomic analyses, is recommended. LEVEL OF EVIDENCE: 3.

Two mechanisms for putrescine-dependent transcriptional expression of the putrescine aminotransferase gene, ygjG, in Escherichia coli.

In this study, on evaluating the physiological function and mechanism of putrescine, we found that putrescine supplementation (1 mM) increases transcription of the putrescine aminotransferase gene, ygjG. Putrescine-dependent expression was confirmed by measuring ß-galactosidase activity and with reverse transcription-polymerase chain reaction. To understand the role of putrescine in ygjG expression, we genetically characterized and found that a knockout mutation in an alternative sigma factor, rpoS, abolished putrescine-dependent ygjG-lacZ expression. In the rpoS mutant, RpoS overexpression complemented the mutant phenotype. However, RpoS overexpression induced ygjG-lacZ expression with putrescine supplementation but not without supplementation. We also found that the loss of putrescine-dependent ygjG-lacZ expression induced by rpoS was completely restored under nitrogen-starvation conditions. The putrescine-dependent expression of ygjG-lacZ under this condition was clearly dependent on another alternative sigma factor, rpoN, and its cognate activator ntrC. These results show that rpoS is required for putrescine-dependent ygjG-lacZ expression, but the effect of putrescine on this expression is not caused by simple modulation of RpoS synthesis. Putrescine-dependent expression of ygjG-lacZ was controlled by at least two sigma factors: rpoS under excess nitrogen conditions and rpoN under nitrogen-starvation conditions. These results suggest that putrescine plays an important role in the nitrogen regulation system.

The predisposing factors for the heterotopic ossification after cervical artificial disc replacement.

BACKGROUND CONTEXT: Heterotopic ossification (HO) is defined as a formation of bone outside the skeletal system. The reported HO occurrence rate in cervical artificial disc replacement (ADR) is unexpectedly high and is known to vary. However, the predisposing factors for HO in cervical ADR have not yet been elucidated. PURPOSE: Investigation of the predisposing factors of HO in cervical arthroplasty and the relationship between degeneration of the cervical spine and HO occurrence. STUDY DESIGN: Retrospective study to discover predisposing factors of HO in cervical arthroplasty. PATIENT SAMPLE: A total of 170 patients who underwent cervical ADR were enrolled including full follow-up clinical and radiologic data. OUTCOME MEASURES: Radiologic outcomes were assessed by identification of HOs according to McAfee's classifications. METHODS: This study enrolled a total of 170 patients who underwent cervical ADR. Pre-existing degenerative change included anterior or posterior osteophytes, ossification of the anterior longitudinal ligament, posterior longitudinal ligament, or ligamentum nuchae. The relationships between basic patient data, pre-existing degenerative change, and HO were investigated using linear logistic regression analysis. RESULTS: Among all 170 patients, HO was found in 69 patients (40.6%). Among the postulated predisposing factors, only male gender and artificial disc device type were shown to be statistically significant. Unexpectedly, preoperative degenerative changes in the cervical spine exerted no significant influence on the occurrence of HOs. The odds ratio of male gender compared with female gender was 2.117. With regard to device type, the odds ratios of Mobi-C (LDR medical, Troyes, France) and ProDisc-C (Synthes, Inc., West Chester, PA, USA) were 5.262 and 7.449, respectively, compared with the Bryan disc. CONCLUSIONS: Definite differences in occurrence rate according to the gender of patients and the prosthesis type were identified in this study. Moreover, factors indefinably expected to influence HO in the past were not shown to be risk factors thereof, the results of which may be meaningful to future studies.