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Sample records for adjacent segment degenerative

  1. Incidence and risk factors of adjacent segment disease following posterior decompression and instrumented fusion for degenerative lumbar disorders.

    PubMed

    Wang, Hui; Ma, Lei; Yang, Dalong; Wang, Tao; Liu, Sen; Yang, Sidong; Ding, Wenyuan

    2017-02-01

    The purpose of this study was to explore incidence and risk factors of adjacent segment disease (ASD) following posterior decompression and instrumented fusion for degenerative lumbar disorders, and hope to provide references in decision making and surgical planning for both spinal surgeon and surgically treated patients.By retrieving the medical records from January 2011 to December 2013 in our hospital, 237 patients were retrospectively reviewed. According to the occurrence of ASD at follow up, patients were divided into 2 groups: ASD and N-ASD group. To investigate risk values for the occurrence of ASD, 3 categorized factors were analyzed statistically: Patient characteristics: age, sex, body mass index (BMI), bone mineral density (BMD), duration. Surgical variables: surgical strategy, number of fusion level, surgery segment, surgery time, blood loss, intraoperative superior facet joint violation. Radiographic parameters: preoperative lumbar lordosis, preoperative angular motion at adjacent segment, preoperative adjacent segment disc degeneration, preoperative paraspinal muscle degeneration.Postoperative ASD was developed in 15 of 237 patients (6.3%) at final follow up. There was no statistically significant difference between the 2 groups in patient characteristics of age, sex composition, BMD, duration, while the BMI was higher in ASD group than that in N-ASD group. There was no difference in surgical variables of surgical strategy, number of fusion level, surgery segment, surgery time, blood loss, while intraoperative superior facet joint violation was more common in ASD group than that in N-ASD group. There was no difference in radiographic parameters of preoperative lumbar lordosis, preoperative paraspinal muscle degeneration, while preoperative adjacent segment disc degeneration were more severe in ASD group than that in N-ASD group. The Logistic regression analysis revealed that, BMI >25 kg/m, preoperative disc degeneration, and superior facet joint

  2. Incidence and risk factors of adjacent segment disease following posterior decompression and instrumented fusion for degenerative lumbar disorders

    PubMed Central

    Wang, Hui; Ma, Lei; Yang, Dalong; Wang, Tao; Liu, Sen; Yang, Sidong; Ding, Wenyuan

    2017-01-01

    Abstract The purpose of this study was to explore incidence and risk factors of adjacent segment disease (ASD) following posterior decompression and instrumented fusion for degenerative lumbar disorders, and hope to provide references in decision making and surgical planning for both spinal surgeon and surgically treated patients. By retrieving the medical records from January 2011 to December 2013 in our hospital, 237 patients were retrospectively reviewed. According to the occurrence of ASD at follow up, patients were divided into 2 groups: ASD and N-ASD group. To investigate risk values for the occurrence of ASD, 3 categorized factors were analyzed statistically: Patient characteristics: age, sex, body mass index (BMI), bone mineral density (BMD), duration. Surgical variables: surgical strategy, number of fusion level, surgery segment, surgery time, blood loss, intraoperative superior facet joint violation. Radiographic parameters: preoperative lumbar lordosis, preoperative angular motion at adjacent segment, preoperative adjacent segment disc degeneration, preoperative paraspinal muscle degeneration. Postoperative ASD was developed in 15 of 237 patients (6.3%) at final follow up. There was no statistically significant difference between the 2 groups in patient characteristics of age, sex composition, BMD, duration, while the BMI was higher in ASD group than that in N-ASD group. There was no difference in surgical variables of surgical strategy, number of fusion level, surgery segment, surgery time, blood loss, while intraoperative superior facet joint violation was more common in ASD group than that in N-ASD group. There was no difference in radiographic parameters of preoperative lumbar lordosis, preoperative paraspinal muscle degeneration, while preoperative adjacent segment disc degeneration were more severe in ASD group than that in N-ASD group. The Logistic regression analysis revealed that, BMI >25 kg/m2, preoperative disc degeneration, and superior

  3. Posterior lumbar dynamic stabilization instead of arthrodesis for symptomatic adjacent-segment degenerative stenosis: description of a novel technique.

    PubMed

    Mashaly, Hazem; Paschel, Erin E; Khattar, Nicolas K; Goldschmidt, Ezequiel; Gerszten, Peter C

    2016-01-01

    OBJECTIVE The development of symptomatic adjacent-segment disease (ASD) is a well-recognized consequence of lumbar fusion surgery. Extension of a fusion to a diseased segment may only lead to subsequent adjacent-segment degeneration. The authors report the use of a novel technique that uses dynamic stabilization instead of arthrodesis for the surgical treatment of symptomatic ASD following a prior lumbar instrumented fusion. METHODS A cohort of 28 consecutive patients was evaluated who developed symptomatic stenosis immediately adjacent to a previous lumbar instrumented fusion. All patients had symptoms of neurogenic claudication refractory to nonsurgical treatment and were surgically treated with decompression and dynamic stabilization instead of extending the fusion construct using a posterior lumbar dynamic stabilization system. Preoperative symptoms, visual analog scale (VAS) pain scores, and perioperative complications were recorded. Clinical outcome was gauged by comparing VAS scores prior to surgery and at the time of last follow-up. RESULTS The mean follow-up duration was 52 months (range 17-94 months). The mean interval from the time of primary fusion surgery to the dynamic stabilization surgery was 40 months (range 10-96 months). The mean patient age was 51 years (range 29-76 years). There were 19 (68%) men and 9 (32%) women. Twenty-three patients (82%) presented with low-back pain at time of surgery, whereas 24 patients (86%) presented with lower-extremity symptoms only. Twenty-four patients (86%) underwent operations that were performed using single-level dynamic stabilization, 3 patients (11%) were treated at 2 levels, and 1 patient underwent 3-level decompression and dynamic stabilization. The most commonly affected and treated level (46%) was L3-4. The mean preoperative VAS pain score was 8, whereas the mean postoperative score was 3. No patient required surgery for symptomatic degeneration rostral to the level of dynamic stabilization during the

  4. Could the Topping-Off Technique Be the Preventive Strategy against Adjacent Segment Disease after Pedicle Screw-Based Fusion in Lumbar Degenerative Diseases? A Systematic Review

    PubMed Central

    Chou, Po-Hsin; Lin, Hsi-Hsien; An, Howard S.; Liu, Kang-Ying

    2017-01-01

    The “topping-off” technique is a new concept applying dynamic or less rigid fixation such as hybrid stabilization device (HSD) or interspinous process device (IPD) for the purpose of avoiding adjacent segment disease (ASD) proximal to the fusion construct. A systematic review of the literature was performed on the effect of topping-off techniques to prevent or decrease the occurrence of ASD after lumbar fusion surgery. We searched through major online databases, PubMed and MEDLINE, using key words related to “topping-off” technique. We reviewed the surgical results of “topping-off” techniques with either HSD or IPD, including the incidence of ASD at two proximal adjacent levels (index and supra-adjacent level) as compared to the fusion alone group. The results showed that the fusion alone group had statistically higher incidence of radiographic (52.6%) and symptomatic (11.6%) ASD at the index level as well as higher incidence (8.1%) of revision surgery. Besides, the HSD (10.5%) and fusion groups (24.7%) had statistically higher incidences of radiographic ASD at supra-adjacent level than the IPD (1%). The findings suggest that the “topping-off” technique may potentially decrease the occurrence of ASD at the proximal motion segments. However, higher quality prospective randomized trials are required prior to wide clinical application. PMID:28321409

  5. Biomechanical evaluation of segmental instability in degenerative lumbar spondylolisthesis.

    PubMed

    Hasegewa, Kazuhiro; Kitahara, Ko; Hara, Toshiaki; Takano, Ko; Shimoda, Haruka

    2009-04-01

    Here we investigated the biomechanical properties of spinal segments in patients with degenerative lumbar spondylolisthesis (DLS) using a novel intraoperative measurement system. The measurement system comprised spinous process holders, a motion generator, a load cell, an optical displacement transducer, and a computer. Cyclic displacement of the holders produced flexion-extension of the segment with all ligamentous structures intact. Stiffness, absorption energy (AE), and neutral zone (NZ) were determined from the load-deformation data. Forty-one patients with DLS (M/F = 15/26, mean age 68.6 years; Group D) were studied. Adjacent segments with normal discs in six patients (M/F = 3/3, mean age 35 years) were included as a control group (Group N). Flexion stiffness was significantly lower in Group D than in Group N. The NZ, however, was significantly greater in Group D than in Group N. Thus, compared to normal segments, spinal segments with DLS had a lower flexion stiffness and a higher NZ. NZs in Group D were, however, widely distributed compared to those in Group N that showed NZ <2 mm/N in all cases, suggesting that the segment with DLS is not always unstable and that the segments with NZ >2 mm/N can be considered as unstable.

  6. Biomechanical evaluation of segmental instability in degenerative lumbar spondylolisthesis

    PubMed Central

    Kitahara, Ko; Hara, Toshiaki; Takano, Ko; Shimoda, Haruka

    2008-01-01

    Here we investigated the biomechanical properties of spinal segments in patients with degenerative lumbar spondylolisthesis (DLS) using a novel intraoperative measurement system. The measurement system comprised spinous process holders, a motion generator, a load cell, an optical displacement transducer, and a computer. Cyclic displacement of the holders produced flexion-extension of the segment with all ligamentous structures intact. Stiffness, absorption energy (AE), and neutral zone (NZ) were determined from the load-deformation data. Forty-one patients with DLS (M/F = 15/26, mean age 68.6 years; Group D) were studied. Adjacent segments with normal discs in six patients (M/F = 3/3, mean age 35 years) were included as a control group (Group N). Flexion stiffness was significantly lower in Group D than in Group N. The NZ, however, was significantly greater in Group D than in Group N. Thus, compared to normal segments, spinal segments with DLS had a lower flexion stiffness and a higher NZ. NZs in Group D were, however, widely distributed compared to those in Group N that showed NZ <2 mm/N in all cases, suggesting that the segment with DLS is not always unstable and that the segments with NZ >2 mm/N can be considered as unstable. PMID:19066987

  7. Biomechanical effects of pedicle screw fixation on adjacent segments.

    PubMed

    Kyaw, Thein Aung; Wang, Zhuo; Sakakibara, Toshihiko; Yoshikawa, Takamasa; Inaba, Tadashi; Kasai, Yuichi

    2014-07-01

    possible range, and it might gradually lead to a degenerative intervertebral disc or progression of spondylolisthesis in the adjacent segments.

  8. Adjacent segment disease and C-ADR: promises fulfilled?

    PubMed Central

    Riew, K Daniel; Schenk-Kisser, Jeannette M.; Skelly, Andrea C.

    2012-01-01

    Study design: Systematic review. Clinical question: Do the rates and timing of adjacent segment disease (ASD) differ between cervical total disc arthroplasty (C-ADR) and anterior cervical discectomy and fusion (ACDF) in patients treated for cervical degenerative disc disease? Methods: A systematic search of MEDLINE/PubMed and bibliographies of key articles was done to identify studies with long-term follow-up for symptomatic and/or radiographic ASD comparing C-ADR with fusion for degenerative disc disease of the cervical spine. The focus was on studies with longer follow-up (48–60 months) of primary US Food and Drug Administration trials of Prestige ST, Prodisc-C, and Bryan devices as available. Trials of other discs with a minimum of 24 months follow-up were considered for inclusion. Studies evaluating lordosis/angle changes at adjacent segments and case series were excluded. Results: From 14 citations identified, four reports from three randomized controlled trials and four nonrandomized studies are summarized. Risk differences between C-ADR and ACF for symptomatic ASD were 1.5%–2.3% and were not significant across RCT reports. Time to development of ASD did not significantly differ between treatments. Rates of radiographic ASD were variable. No meaningful comparison of ASD rates based on disc design was possible. No statistical differences in adjacent segment range of motion were noted between treatment groups. Conclusion: Our analysis reveals that, to date, there is no evidence that arthroplasty decreases ASD compared with ACDF; the promise of arthroplasty decreasing ASD has not been fulfilled. PMID:23236312

  9. Adjacent Segment Disease in the Cervical and Lumbar Spine.

    PubMed

    Tobert, Daniel G; Antoci, Valentin; Patel, Shaun P; Saadat, Ehsan; Bono, Christopher M

    2017-04-01

    Adjacent segment disease (ASD) is disappointing long-term outcome for both the patient and clinician. In contrast to adjacent segment degeneration, which is a common radiographic finding, ASD is less common. The incidence of ASD in both the cervical and lumbar spine is between 2% and 4% per year, and ASD is a significant contributor to reoperation rates after spinal arthrodesis. The etiology of ASD is multifactorial, stemming from existing spondylosis at adjacent levels, predisposed risk to degenerative changes, and altered biomechanical forces near a previous fusion site. Numerous studies have sought to identify both patient and surgical risk factors for ASD, but a consistent, sole predictor has yet to be found. Spinal arthroplasty techniques seek to preserve physiological biomechanics, thereby minimizing the risk of ASD, and long-term clinical outcome studies will help quantify its efficacy. Treatment strategies for ASD are initially nonoperative, provided a progressive neurological deficit is not present. The spine surgeon is afforded many surgical strategies once operative treatment is elected. The goal of this manuscript is to consider the etiologies of ASD, review its manifestations, and offer an approach to treatment.

  10. Adjacent Segment Pathology after Anterior Cervical Fusion

    PubMed Central

    Chung, Jae Yoon; Park, Jong-Beom; Seo, Hyoung-Yeon

    2016-01-01

    Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion. PMID:27340541

  11. New Classification for Clinically Symptomatic Adjacent Segment Pathology in Cervical Disc Disease

    PubMed Central

    2015-01-01

    Study Design Clinical adjacent segment pathology (CASP) is common after cervical disc surgery. A critical examination of 320 patients operated for cervical disc prolapse revealed that CASP can also occur in patients with congenital and degenerative fusion of cervical spine. This has not been studied in depth and there is a need for a practically applicable classification of CASP. Purpose To develop a new classification scheme of CASP. Overview of Literature A review of the literature did not reveal a practically applicable classification incorporating the occurrence of CASP in congenital and degenerative fusion cases. Methods This was a retrospective analysis of 320 patients operated (509 disc spaces) on for cervical disc prolapse. Cases (n=316) were followed-up for 3-11 years. Random sampling of 220 patients with postoperative magnetic resonance imaging (MRI) in 165 cases was analyzed. Results Six symptomatic CASP cases required resurgery (1.9%), eight cases involved MRI proven CASP with axial neck pain only and 13 patients were asymptomatic with radiological adjacent segment pathology (RASP). The frequency rate was 8.5% (27/316). Four cases of congenital or degenerative fusion of vertebra developed CASP requiring surgery. CASP is classified as primary or secondary follows. Primary A1 was congenital fusion of vertebra and primary A2 was degenerative fusion of the vertebra. Secondary, which was after cervical disc surgery, comprised B1 (RASP in asymptomatic patients), B2 (CASP in patients with axial neck pain), and B3 (CASP with myeloradiculopathy). B3 was subdivided into single-level CASP (B3a) and multiple-level CASP (B3b). Conclusions Symptomatic CASP requiring resurgery is infrequent. CASP can occur in patients with congenital and degenerative fusion of the cervical spine. A new classification for CASP along with treatment strategy is proposed. Patients in Primary CASP and B3 CASP require resurgery while others require only observation. PMID:26712514

  12. Evaluation of Degenerative Lumbar Scoliosis After Short Segment Decompression and Fusion

    PubMed Central

    Wang, Naiguo; Wang, Dachuan; Wang, Feng; Tan, Bingyi; Yuan, Zenong

    2015-01-01

    Abstract The objective of this study was to investigate short segment decompression of degenerative lumbar scoliosis (DLS) and the efficiency of fusion treatment. After DLS surgery, the patients were retrospectively reviewed using the VAS (visual analog scale) and ODI (Oswestry Disability Index) to assess clinical outcomes. All patients underwent posterior lumbar decompressive laminectomy, pedicle screw internal fixation, and posterolateral bone graft fusion surgery. Radiographic measurements included the scoliotic Cobb angle, the fused Cobb angle, the anterior intervertebral angle (AIA), the sagittal intervertebral angle (SIA), and lumbar lordosis angle. The relationships between these parameters were examined by bivariate Pearson analysis and linear regression analysis. Preoperatively, the Cobb angle at the scoliotic segment was 15.4°, which decreased to 10.2° immediately following surgery (P < 0.05). The AIA significantly increased by the last follow-up (4.4 ± 3.4) compared with pre- and postoperative values (2.5 ± 2.8 and 2.2 ± 2.4, respectively; P < 0.05). However, the scoliotic Cobb angle and the AIA did not correlate with the VAS or ODI scores. At the final follow-up, no patients had pseudoarthrosis or internal instrumentation-related complications. Short fusion surgical treatment results in limited DLS correction, with correction loss over time. The AIA between the upper adjacent segment and proximal fused vertebra continues to increase postoperatively, which does not exacerbate clinical symptoms, as reflected by the low reoperation rates for repairing degeneration at adjacent levels. PMID:26632679

  13. Management of adjacent segment disease after cervical spinal fusion.

    PubMed

    Kepler, Christopher K; Hilibrand, Alan S

    2012-01-01

    Adjacent segment disease (ASD) was described after long-term follow-up of patients treated with cervical fusion. The term describes new-onset radiculopathy or myelopathy referable to a motion segment adjacent to previous arthrodesis and often attributed to alterations in the biomechanical environment after fusion. Evidence suggests that ASD affects between 2% and 3% of patients per year. Although prevention of ASD was one major impetus behind the development of motion-sparing surgery, the literature does not yet clearly distinguish a difference in the rate of ASD between fusion and disk replacement. Surgical techniques during index surgery may reduce the rate of ASD.

  14. Surgical treatment of complex axis fractures with adjacent segment instability.

    PubMed

    Wang, Lei; Xia, Tian; Dong, Shuanghai; Zhao, Qinghua; Tian, Jiwei

    2012-03-01

    This study investigates the clinical and radiographic characteristics of complex axis fractures with adjacent segment instability and describes the outcome of surgical treatment. Twenty-one patients (14 male, seven female; mean age=34 years) with complex axis fractures and adjacent segment instability who were treated between August 2003 and June 2009 were retrospectively reviewed. Treatment selection was based on fracture type and stability of the upper cervical segments. All patients were immobilized with a hard collar for three months after surgery. The mean follow-up period was 12 months (range=6-36 months). No intraoperative surgery-related complications were observed and fusion was achieved in all patients. The outcome was excellent for 17 patients, good for two patients, fair for one patient, and poor for one patient. The upper cervical segments that can become unstable due to complex axis fractures include the atlantoaxial and C2-3 joints. Recommended surgical treatments produce good results.

  15. Lumbar Facet Joint Motion in Patients with Degenerative Disc Disease at Affected and Adjacent Levels

    PubMed Central

    Li, Weishi; Wang, Shaobai; Xia, Qun; Passias, Peter; Kozanek, Michal; Wood, Kirkham; Li, Guoan

    2013-01-01

    Study Design Controlled laboratory study. Objective To evaluate the effect of lumbar degenerative disc diseases (DDDs) on motion of the facet joints during functional weight-bearing activities. Summary of Background Data It has been suggested that DDD adversely affects the biomechanical behavior of the facet joints. Altered facet joint motion, in turn, has been thought to associate with various types of lumbar spine pathology including facet degeneration, neural impingement, and DDD progression. However, to date, no data have been reported on the motion patterns of the lumbar facet joint in DDD patients. Methods Ten symptomatic patients of DDD at L4–S1 were studied. Each participant underwent magnetic resonance images to obtain three-dimensional models of the lumbar vertebrae (L2–S1) and dual fluoroscopic imaging during three characteristic trunk motions: left-right torsion, left-right bending, and flexion-extension. In vivo positions of the vertebrae were reproduced by matching the three-dimensional models of the vertebrae to their outlines on the fluoroscopic images. The kinematics of the facet joints and the ranges of motion (ROMs) were compared with a group of healthy participants reported in a previous study. Results In facet joints of the DDD patients, there was no predominant axis of rotation and no difference in ROMs was found between the different levels. During left-right torsion, the ROMs were similar between the DDD patients and the healthy participants. During left-right bending, the rotation around mediolateral axis at L4–L5, in the DDD patients, was significantly larger than that of the healthy participants. During flexion-extension, the rotations around anterioposterior axis at L4–L5 and around craniocaudal axis at the adjacent level (L3–L4), in the DDD patients, were also significantly larger, whereas the rotation around mediolateral axis at both L2–L3 and L3–L4 levels in the DDD patients were significantly smaller than those of the

  16. Repeated adjacent segment diseases and fractures in osteoporotic patients: a case report

    PubMed Central

    Chen, Hsin-Yao; Chen, Chiu-Liang; Chen, Wei-Liang

    2016-01-01

    Background Pedicle screw instrumentation for treating spinal disorder is becoming increasingly widespread. Many studies have advocated its use to facilitate rigid fixation for spine; however, adjacent segmental disease is a known complication. Instrumented fusion for osteoporotic spines remains a significant challenge for spine surgeons. Prophylactic vertebroplasty for adjacent vertebra has been reported to reduce the complications of junctional compression fractures but has raised a new problem of vertebral subluxation. This case report is a rare and an extreme example with many surgical complications caused by repeated instrumented fusion for osteoporotic spine in a single patient. This patient had various complications including adjacent segmental disease, vertebral subluxation, and junctional fractures on radiographs and magnetic resonance images. Case presentation An 81-year-old Taiwanese woman underwent decompression and instrumented fusion of L4-L5 in Taiwan 10 years ago. Due to degenerative spinal stenosis of L3-L4 and L2-L3, she had decompression with instrumented fusion from L5 to L1 at the previous hospital. However, catastrophic vertebral subluxations with severe neurologic compromise occurred, and she underwent salvage surgeries twice with prolonged instrumented fusion from L5 to T2. The surgeries did not resolve her problems of spinal instability and neurologic complications. Eventually, the patient remained with a Frankel Grade C spinal cord injury. Conclusion Adjacent segmental disease, junctional fracture, and vertebral subluxation are familiar complications following instrumented spinal fusion surgeries for osteoporotic spines. Neurologic injuries following long instrumentation are often serious and difficult to address with surgery alone. Conservative treatments should always be contemplated as an alternative method for patients with poor bone stock. PMID:27555778

  17. Study of the influence of degenerative intervertebral disc changes on the deformation behavior of the cervical spine segment in flexion

    NASA Astrophysics Data System (ADS)

    Kolmakova, Tatyana V.

    2016-11-01

    The paper describes the model of the cervical spine segment (C3-C4) and the calculation results of the deformation behavior of the segment under degenerative changes of the intervertebral disc. The segment model was built based on the experimental literature data taking into account the presence of the cortical and cancellous bone tissue of vertebral bodies. The calculation results show that degenerative changes of the intervertebral disc cause the immobility of the C3 vertebra at flexion.

  18. Minimum 10-Year Follow-up Study of Anterior Lumbar Interbody Fusion for Degenerative Spondylolisthesis: Progressive Pattern of the Adjacent Disc Degeneration

    PubMed Central

    Yasuda, Taketoshi; Hori, Takeshi; Suzuki, Kayo; Kawaguchi, Yoshiharu

    2012-01-01

    Study Design Retrospective study. Purpose The aims of the current study are to evaluate the minimum 10-year follow-up clinical results of anterior lumbar interbody fusion (ALIF) for degenerative spondylolisthesis. Overview of Literature ALIF has been widely used as a treatment regimen in the management of lumbar spondylolisthesis. Still much controversy exists regarding the factors that affect the postoperative clinical outcomes. Methods The author performed a retrospective review of 20 patients with degenerative spondylolisthesis treated with ALIF (follow-up, 16.4 years). The clinical results were assessed by the Japanese Orthopaedic Association (JOA) score for low back pain, vertebral slip and disc height index on the radiographs. Results The mean preoperative JOA score was 7.1 ± 1.8 points (15-point-method). At 1 year, 5 years, and 10 years or more after surgery, the JOA scores were assessed as 12.4 ± 2.2 points, 12.7 ± 2.6 points, 12.0 ± 2.5 points, respectively (excluding the data of reoperated cases). The adjacent disc degeneration developed in all cases during the long-term follow-up. The progressive pattern of disc degeneration was divided into three types. Initially, disc degeneration occurred due to disc space narrowing. After that, the intervertebral discs showed segmental instability with translation at the upper level. But the lower discs showed osteophyte formation, and occasionally lead to the collapse or spontaneous union. Conclusions The clinical results of the long-term follow-up data after ALIF became worse due to the adjacent disc degeneration. The progressive pattern of disc degeneration was different according to the adjacent levels. PMID:22708014

  19. Preliminary results of automated removal of degenerative joint disease in bone scan lesion segmentation

    NASA Astrophysics Data System (ADS)

    Chu, Gregory H.; Lo, Pechin; Kim, Hyun J.; Auerbach, Martin; Goldin, Jonathan; Henkel, Keith; Banola, Ashley; Morris, Darren; Coy, Heidi; Brown, Matthew S.

    2013-03-01

    Whole-body bone scintigraphy (or bone scan) is a highly sensitive method for visualizing bone metastases and is the accepted standard imaging modality for detection of metastases and assessment of treatment outcomes. The development of a quantitative biomarker using computer-aided detection on bone scans for treatment response assessment may have a significant impact on the evaluation of novel oncologic drugs directed at bone metastases. One of the challenges to lesion segmentation on bone scans is the non-specificity of the radiotracer, manifesting as high activity related to non-malignant processes like degenerative joint disease, sinuses, kidneys, thyroid and bladder. In this paper, we developed an automated bone scan lesion segmentation method that implements intensity normalization, a two-threshold model, and automated detection and removal of areas consistent with non-malignant processes from the segmentation. The two-threshold model serves to account for outlier bone scans with elevated and diffuse intensity distributions. Parameters to remove degenerative joint disease were trained using a multi-start Nelder-Mead simplex optimization scheme. The segmentation reference standard was constructed manually by a panel of physicians. We compared the performance of the proposed method against a previously published method. The results of a two-fold cross validation show that the overlap ratio improved in 67.0% of scans, with an average improvement of 5.1% points.

  20. Congenital stenosis and adjacent segment disease in the cervical spine.

    PubMed

    Eubanks, Jason David; Belding, Jon; Schnaser, Erik; Rowan, Andrew; Moffitt, Gable; Weaver, John; Reich, Michael S; Bechtel, Chris; Xie, Ke; Gande, Abhiram; Hohl, Justin; Braly, Brett; Hilibrand, Alan; Kang, James D

    2013-10-01

    Symptomatic adjacent segment disease (ASD) after anterior cervical fusion (ACF) is reported in 25% of patients at 10 years postoperatively. Debate continues as to whether this degeneration is due to the natural history of the disk or the changed biomechanics after ACF. This study explored whether congenital stenosis predisposes patients to an increased incidence of ASD after ACF. A retrospective review of 635 patients with myelopathy or radiculopathy was performed; 364 patients had complete records for review. Patients underwent 1- to 5-level ACF (94 one-level, 145 two-level, 79 three-level, 45 four-level, and 1 five-level). Radiographs were evaluated for bony congenital stenosis using validated parameters, and ASD was measured according to Hilibrand's criteria and correlated with symptomatic ASD. Congenital stenosis was found in 21.7% of patients and radiographic ASD in 33.5%, with a significant association between these parameters. However, symptomatic ASD occurred in 11.8% of patients; no association between congenital stenosis and symptomatic ASD or myelopathy and ASD was found. Clinical results demonstrated excellent or good Robinson scores in 86.2% of patients and Odom scores in 87% of patients. Despite mostly excellent to good outcomes, symptomatic ASD is common after ACF. Although congenital stenosis appears to increase the incidence of radiographic ASD, it does not appear to predict symptomatic ASD.

  1. Radiological Assessment of the Effect of Congenital C3-4 Synostosis on Adjacent Segments

    PubMed Central

    Moon, Myung-Sang; Kwon, Ki-Tae; Kim, Sung-Su; Lin, Jin-Fu; Lee, Bong-Jin

    2015-01-01

    Study Design Retrospective case series. Purpose To assess the effect of non-kyphotic aligned congenital C3-4 synostosis on the adjacent segment in 10 patients. Overview of Literature In the cervical spine, fusion disease at the adjacent motion segments may be a risk factor for potential neurological compromise and death. Methods Radiograms of 10 patients 13 to 69 years of age presenting with neck/shoulder discomfort or pain with or without trauma history were examined. C3-4 synostosis was found incidentally in all patients on routine examination radiographs of cervical spine. Results Adjacent segment disease (ASD) was not found in the three patients younger than 39 years of age. Five of the 10 (50%) patients, including a 67-year-old man, did not develop spondylosis in any of the cervical mobile segments. Spondylosis was observed only in the caudal 1-2 mobile segments in the remaining five patients. The youngest was a 40-year-old male who had spondylosis in the two caudal mobile segments (C4-5 and C5-6). Spondylosis was limited to the two close caudal mobile segments and was not in the cranial segments. Flaring of the lower part of synostotic vertebra associated with advanced narrowed degenerate disc was evident in five patients. Conclusions Mobile segment spondylosis in the individuals with congenital monosegment C3-4 synostosis over age of 40 years may be a natural manifestation of aging and is not solely an adjacent segment disease directly and fully related with congenital C3-4 synostosis. PMID:26713122

  2. Adjacent Segment Disease in a Patient With Klippel-Feil Syndrome and Radiculopathy: Surgical Treatment With Two-Level Disc Replacement

    PubMed Central

    Reyes-Sánchez, Alejandro; Rosales-Olivares, Luis Miguel

    2007-01-01

    Klippel-Feil syndrome (KFS) is a complex congenital condition characterized by improper segmentation of cervical motion segments that could contribute to undesirable adjacent segment degeneration. KFS patients have a strong tendency to present with disease in the adjacent segments. When this condition is present, anterior decompression followed by total disc replacement can be performed safely and can lead to good clinical results. This treatment has theoretical advantages compared with anterior decompression and fusion. Comparative studies and long-term follow-up are needed. Complications associated with fusion include loss of a motion segment, disc height loss, subsidence of the graft, progressive degenerative changes at the adjacent level, graft-related complications, and graft-site complications. Such new technologies as motion preservation spine arthroplasty represent attempts to avoid these complications. Here we present a case report of a 62-year-old female patient with type I congenital fusion at the C5–6 level, with a history of neck pain and right radiculopathy at C5–7. X-rays and MRI show evidence of adjacent segment degeneration at levels above and below congenital fusion. The patient's preoperative visual analog score (VAS) for neck pain was 7 out of a possible 10, her score for right upper extremity pain was 8 out of 10, and her Neck Disability Index (NDI) was 32%. Surgical treatment consisted of anterior decompression and total disc replacement at both levels. At 1-year follow-up, the patient's VAS for neck pain was 2 out of 10, her VAS score for right upper extremity pain was 1 of 10, and her NDI was 9%. PMID:25802590

  3. Adjacent segment disease in a patient with klippel-feil syndrome and radiculopathy: surgical treatment with two-level disc replacement.

    PubMed

    Reyes-Sánchez, Alejandro; Zárate-Kalfópulos, Barón; Rosales-Olivares, Luis Miguel

    2007-01-01

    Klippel-Feil syndrome (KFS) is a complex congenital condition characterized by improper segmentation of cervical motion segments that could contribute to undesirable adjacent segment degeneration. KFS patients have a strong tendency to present with disease in the adjacent segments. When this condition is present, anterior decompression followed by total disc replacement can be performed safely and can lead to good clinical results. This treatment has theoretical advantages compared with anterior decompression and fusion. Comparative studies and long-term follow-up are needed. Complications associated with fusion include loss of a motion segment, disc height loss, subsidence of the graft, progressive degenerative changes at the adjacent level, graft-related complications, and graft-site complications. Such new technologies as motion preservation spine arthroplasty represent attempts to avoid these complications. Here we present a case report of a 62-year-old female patient with type I congenital fusion at the C5-6 level, with a history of neck pain and right radiculopathy at C5-7. X-rays and MRI show evidence of adjacent segment degeneration at levels above and below congenital fusion. The patient's preoperative visual analog score (VAS) for neck pain was 7 out of a possible 10, her score for right upper extremity pain was 8 out of 10, and her Neck Disability Index (NDI) was 32%. Surgical treatment consisted of anterior decompression and total disc replacement at both levels. At 1-year follow-up, the patient's VAS for neck pain was 2 out of 10, her VAS score for right upper extremity pain was 1 of 10, and her NDI was 9%.

  4. Acquired degenerative changes of the intervertebral segments at and suprajacent to the lumbosacral junction. A radioanatomic analysis of the nondiskal structures of the spinal column and perispinal soft tissues.

    PubMed

    Jinkins, J R

    2001-01-01

    In earlier evolutionary times, mammals were primarily quadrupeds. However, other bipeds have also been represented during the course of the Earth's several billion year history. In many cases, either the bipedal stance yielded a large tail and hypoplastic upper extremities (e.g., Tyrannosaurus rex and the kangaroo), or it culminated in hypoplasia of the tail and further development and specialization of the upper extremities (e.g., nonhuman primates and human beings). In the human species this relatively recently acquired posture resulted in a more or less pronounced lumbosacral kyphosis. In turn, certain compensatory anatomic features have since occurred. These include the normal characteristic posteriorly directed wedge-shape of the L5 vertebral body and the L5-S1 intervertebral disk; the L4 vertebral body and the L4-L5 disk may be similarly visibly affected. These compensatory mechanisms, however, have proved to be functionally inadequate over the long term of the human life span. Upright posture also leads to increased weight bearing in humans that progressively causes excess stresses at and suprajacent to the lumbosacral junction. These combined factors result in accelerated aging and degenerative changes and a predisposition to frank biomechanical failure of the subcomponents of the spinal column in these spinal segments. One other specific problem that occurs at the lumbosacral junction that predisposes toward premature degeneration is the singular relationship that exists between a normally mobile segment of spine (i.e., the lumbar spine) and a normally immobile one (i.e., the sacrum). It is well known that mobile spinal segments adjacent to congenitally or acquired fused segments have a predilection toward accelerated degenerative changes. The only segment of the spine in which this is invariably normally true is at the lumbosacral junction (i.e., the unfused lumbar spine adjoining the fused sacrum). Nevertheless, biomechanical failures of the human spine

  5. Symptomatic Adjacent Segment Pathology after Posterior Lumbar Interbody Fusion for Adult Low-Grade Isthmic Spondylolisthesis

    PubMed Central

    Sakaura, Hironobu; Yamashita, Tomoya; Miwa, Toshitada; Ohzono, Kenji; Ohwada, Tetsuo

    2013-01-01

    The incidence of symptomatic adjacent segment pathology (ASP) after fusion surgery for adult low-grade isthmic spondylolisthesis (IS) has been reported to be relatively low compared with other lumbar disease entities. However, there has been no study of symptomatic ASP incidence using posterior lumbar interbody fusion (PLIF) with pedicle screw instrumentation. We investigated the incidence of symptomatic ASP after PLIF with pedicle screw instrumentation for adult low-grade IS and identified significant risk factors for symptomatic ASP. We retrospectively studied records of 40 consecutive patients who underwent PLIF with pedicle screw instrumentation at the Department of Orthopaedic Surgery, Kansai Rosai Hospital, Amagasaki, Japan. The patients were followed for ≥ 4 years. Patients' medical records were retrospectively examined for evidence of symptomatic ASP. Age at time of surgery, sex, fusion level, whole lumbar lordosis, segmental lordosis, preexisting laminar inclination angle, and facet tropism at the cranial fusion segment were analyzed to identify risk factors for symptomatic ASP. Four patients (ASP group) developed symptomatic ASP at the cranial segment adjacent to the fusion. There were no significant differences in age, sex, fusion level, lumbar lordosis, segmental lordosis, or facet tropism at the cranial segment adjacent to the fusion between the ASP and the non-ASP groups. In contrast, laminar inclination angle at the cranial vertebra adjacent to the fusion was significantly higher in the ASP group than in the non-ASP group. Four patients (10%) developed symptomatic ASP after PLIF with transpedicular fixation for adult low-grade IS. Preexisting laminar horizontalization at the cranial vertebra adjacent to the fusion was a significant risk factor for symptomatic ASP. PMID:24436872

  6. Best Merge Region Growing Segmentation with Integrated Non-Adjacent Region Object Aggregation

    NASA Technical Reports Server (NTRS)

    Tilton, James C.; Tarabalka, Yuliya; Montesano, Paul M.; Gofman, Emanuel

    2012-01-01

    Best merge region growing normally produces segmentations with closed connected region objects. Recognizing that spectrally similar objects often appear in spatially separate locations, we present an approach for tightly integrating best merge region growing with non-adjacent region object aggregation, which we call Hierarchical Segmentation or HSeg. However, the original implementation of non-adjacent region object aggregation in HSeg required excessive computing time even for moderately sized images because of the required intercomparison of each region with all other regions. This problem was previously addressed by a recursive approximation of HSeg, called RHSeg. In this paper we introduce a refined implementation of non-adjacent region object aggregation in HSeg that reduces the computational requirements of HSeg without resorting to the recursive approximation. In this refinement, HSeg s region inter-comparisons among non-adjacent regions are limited to regions of a dynamically determined minimum size. We show that this refined version of HSeg can process moderately sized images in about the same amount of time as RHSeg incorporating the original HSeg. Nonetheless, RHSeg is still required for processing very large images due to its lower computer memory requirements and amenability to parallel processing. We then note a limitation of RHSeg with the original HSeg for high spatial resolution images, and show how incorporating the refined HSeg into RHSeg overcomes this limitation. The quality of the image segmentations produced by the refined HSeg is then compared with other available best merge segmentation approaches. Finally, we comment on the unique nature of the hierarchical segmentations produced by HSeg.

  7. Degenerative Pathways of Lumbar Motion Segments - A Comparison in Two Samples of Patients with Persistent Low Back Pain

    PubMed Central

    Jensen, Rikke K.; Kjaer, Per; Jensen, Tue S.; Albert, Hanne; Kent, Peter

    2016-01-01

    Background Magnetic resonance imaging (MRI) is used to identify spinal pathoanatomy in people with persistent low back pain. However, the clinical relevance of spinal degenerative MRI findings remains uncertain. Although multiple MRI findings are almost always present at the same time, research into the association with clinical outcomes (such as pain) has predominantly focused on individual MRI findings. This study aimed to: (i) investigate how multiple MRI lumbar spine findings cluster together within two different samples of patients with low back pain, (ii) classify these clusters into hypothetical pathways of degeneration based on scientific knowledge of disco-vertebral degeneration, and (iii) compare these clusters and degenerative pathways between samples. Methods We performed a secondary cross-sectional analysis on two dissimilar MRI samples collected in a hospital department: (1) data from the spinal MRI reports of 4,162 low back pain patients and (2) data from an MRI research protocol of 631 low back pain patients. Latent Class Analysis was used in both samples to cluster MRI findings from lumbar motion segments. Using content analysis, each cluster was then categorised into hypothetical pathways of degeneration. Results Six clusters of MRI findings were identified in each of the two samples. The content of the clusters in the two samples displayed some differences but had the same overall pattern of MRI findings. Although the hypothetical degenerative pathways identified in the two samples were not identical, the overall pattern of increasing degeneration within the pathways was the same. Conclusions It was expected that different clusters could emerge from different samples, however, when organised into hypothetical pathways of degeneration, the overall pattern of increasing degeneration was similar and biologically plausible. This evidence of reproducibility suggests that Latent Class Analysis may provide a new approach to investigating the

  8. Does Wallis implant reduce adjacent segment degeneration above lumbosacral instrumented fusion?

    PubMed Central

    Repantis, Thomas; Zacharatos, Spyros; Zafiropoulos, Andreas

    2009-01-01

    Delayed complications following lumbar spine fusion may occur amongst which is adjacent segment degeneration (ASD). Although interspinous implants have been successfully used in spinal stenosis to authors’ knowledge such implants have not been previously used to reduce ASD in instrumented lumbar fusion. This prospective controlled study was designed to investigate if the implantation of an interspinous implant cephalad to short lumbar and lumbosacral instrumented fusion could eliminate the incidence of ASD and subsequently the related re-operation rate. Groups W and C enrolled initially each 25 consecutive selected patients. Group W included patients, who received the Wallis interspinous implant in the unfused vertebral segment cephalad to instrumentation and the group C selected age-, diagnosis-, level-, and instrumentation-matched to W group patients without interspinous implant (controls). The inclusion criterion for Wallis implantation was UCLA arthritic grade UCLA grade II in the adjacent two segments cephalad to instrumentation. All patients suffered from symptomatic spinal stenosis and underwent decompression and 2–4 levels stabilization with rigid pedicle screw fixation and posterolateral fusion by a single surgeon. Lumbar lordosis, disc height (DH), segmental range of motion (ROM), and percent olisthesis in the adjacent two cephalad to instrumentation segments were measured preoperatively, and postoperatively until the final evaluation. VAS, SF-36, and Oswestry Disability Index (ODI) were used. One patient of group W developed pseudarthrosis: two patients of group C deep infection and one patient of group C ASD in the segment below instrumentation and were excluded from the final evaluation. Thus, 24 patients of group W and 21 in group C aged 65+ 13 and 64+ 11 years, respectively were included in the final analysis. The follow-up averaged 60 ± 6

  9. Effect of the Degenerative State of the Intervertebral Disk on the Impact Characteristics of Human Spine Segments

    PubMed Central

    Wilson, Sara E.; Alkalay, Ron N.; Myers, Elizabeth

    2013-01-01

    Models of the dynamic response of the lumbar spine have been used to examine vertebral fractures (VFx) during falls and whole body vibration transmission in the occupational setting. Although understanding the viscoelastic stiffness or damping characteristics of the lumbar spine are necessary for modeling the dynamics of the spine, little is known about the effect of intervertebral disk degeneration on these characteristics at high loading rates. We hypothesize that disk degeneration significantly affects the viscoelastic response of spinal segments to high loading rate. We additionally hypothesize the lumbar spine stiffness and damping characteristics are a function of the degree of preload. A custom, pendulum impact tester was used to impact 19 L1–L3 human spine segments with an end mass of 20.9 kg under increasing preloads with the resulting force response measured. A Kelvin–Voigt model, fitted to the frequency and decay response of the post-impact oscillations was used to compute stiffness and damping constants. The spine segments exhibited a second-order, under-damped response with stiffness and damping values of 17.9–754.5 kN/m and 133.6–905.3 Ns/m respectively. Regression models demonstrated that stiffness, but not damping, significantly correlated with preload (p < 0.001). Degenerative disk disease, reflected as reduction in magnetic resonance T2 relaxation time, was weakly correlated with change in stiffness at low preloads. This study highlights the need to incorporate the observed non-linear increase in stiffness of the spine under high loading rates in dynamic models of spine investigating the effects of a fall on VFx and those investigating the response of the spine to vibration. PMID:25024122

  10. Effect of the Degenerative State of the Intervertebral Disk on the Impact Characteristics of Human Spine Segments.

    PubMed

    Wilson, Sara E; Alkalay, Ron N; Myers, Elizabeth

    2013-01-01

    Models of the dynamic response of the lumbar spine have been used to examine vertebral fractures (VFx) during falls and whole body vibration transmission in the occupational setting. Although understanding the viscoelastic stiffness or damping characteristics of the lumbar spine are necessary for modeling the dynamics of the spine, little is known about the effect of intervertebral disk degeneration on these characteristics at high loading rates. We hypothesize that disk degeneration significantly affects the viscoelastic response of spinal segments to high loading rate. We additionally hypothesize the lumbar spine stiffness and damping characteristics are a function of the degree of preload. A custom, pendulum impact tester was used to impact 19 L1-L3 human spine segments with an end mass of 20.9 kg under increasing preloads with the resulting force response measured. A Kelvin-Voigt model, fitted to the frequency and decay response of the post-impact oscillations was used to compute stiffness and damping constants. The spine segments exhibited a second-order, under-damped response with stiffness and damping values of 17.9-754.5 kN/m and 133.6-905.3 Ns/m respectively. Regression models demonstrated that stiffness, but not damping, significantly correlated with preload (p < 0.001). Degenerative disk disease, reflected as reduction in magnetic resonance T2 relaxation time, was weakly correlated with change in stiffness at low preloads. This study highlights the need to incorporate the observed non-linear increase in stiffness of the spine under high loading rates in dynamic models of spine investigating the effects of a fall on VFx and those investigating the response of the spine to vibration.

  11. Radiologic Evaluation of Degeneration in Isthmic and Degenerative Spondylolisthesis

    PubMed Central

    Jeong, Hyun-Yoon; Sohn, Hong-Moon; Park, Sang-Ha

    2013-01-01

    Study Design A cross-sectional imaging study. Purpose The objective was to assess the degree of degeneration and the associated factors through imaging studies of the lesion segment and the adjacent superior and inferior segments of isthmic and degenerative spondylolisthesis. Overview of Literature Few articles existed for degeneration and related factors in isthmic and degenerative spondylolisthesis. Methods The subjects were 95 patients diagnosed with spondylolisthesis. Simple plain radiographs including flexion and extension and magnetic resonance imaging were used to investigate the degree of translation, disc degeneration, high intensity zone (HIZ) lesion, Schmorl's node (SN) and Modic changes. Results Advanced disc degeneration, grade 5, was shown to be significant in the index segment of the isthmic type (p=0.034). Overall, type 2 Modic change was most common in both groups and also, it was observed more in the isthmus group, specifically, the index segment compared to the degenerative group (p=0.03). For the SN, compared to the degenerative type, the isthmus type had a significantly high occurrence in the index segment (p=0.04). For the HIZ lesions, the isthmus type had a higher occurrence than the degenerative type, especially in the upper segment (p=0.03). Conclusions Most advanced disc degeneration, fifth degree, SN and Modic change occurred more frequently in the lesions of the isthmus type. HIZ lesions were observed more in the isthmus type, especially in the segment superior to the lesion. PMID:23508359

  12. Reduction in adjacent-segment degeneration after multilevel posterior lumbar interbody fusion with proximal DIAM implantation.

    PubMed

    Lu, Kang; Liliang, Po-Chou; Wang, Hao-Kuang; Liang, Cheng-Loong; Chen, Jui-Sheng; Chen, Tai-Been; Wang, Kuo-Wei; Chen, Han-Jung

    2015-08-01

    OBJECT Multilevel long-segment lumbar fusion poses a high risk for future development of adjacent-segment degeneration (ASD). Creating a dynamic transition zone with an interspinous process device (IPD) proximal to the fusion has recently been applied as a method to reduce the occurrence of ASD. The authors report their experience with the Device for Intervertebral Assisted Motion (DIAM) implanted proximal to multilevel posterior lumbar interbody fusion (PLIF) in reducing the development of proximal ASD. METHODS This retrospective study reviewed 91 cases involving patients who underwent 2-level (L4-S1), 3-level (L3-S1), or 4-level (L2-S1) PLIF. In Group A (42 cases), the patients received PLIF only, while in Group B (49 cases), an interspinous process device, a DIAM implant, was put at the adjacent level proximal to the PLIF construct. Bone resection at the uppermost segment of the PLIF was equally limited in the 2 groups, with preservation of the upper portion of the spinous process/lamina and the attached supraspinous ligament. Outcome measures included a visual analog scale (VAS) for low-back pain and leg pain and the Oswestry Disability Index (ODI) for functional impairment. Anteroposterior and lateral flexion/extension radiographs were used to evaluate the fusion status, presence and patterns of ASD, and mobility of the DIAM-implanted segment. RESULTS Solid interbody fusion without implant failure was observed in all cases. Radiographic ASD occurred in 20 (48%) of Group A cases and 3 (6%) of Group B cases (p < 0.001). Among the patients in whom ASD was identified, 9 in Group A and 3 in Group B were symptomatic; of these patients, 3 in Group A and 1 in Group B underwent a second surgery for severe symptomatic ASD. At 24 months after surgery, Group A patients fared worse than Group B, showing higher mean VAS and ODI scores due to symptoms related to ASD. At the final follow-up evaluations, as reoperations had been performed to treat symptomatic ASD in some

  13. Preserving Posterior Complex Can Prevent Adjacent Segment Disease following Posterior Lumbar Interbody Fusion Surgeries: A Finite Element Analysis

    PubMed Central

    Huang, Yun-Peng; Du, Cheng-Fei; Cheng, Cheng-Kung; Zhong, Zheng-Cheng; Chen, Xuan-Wei; Wu, Gui; Li, Zhe-Cheng; Ye, Jin-Duo; Lin, Jian-Hua; Wang, Li Zhen

    2016-01-01

    Objective To investigate the biomechanical effects of the lumbar posterior complex on the adjacent segments after posterior lumbar interbody fusion (PLIF) surgeries. Methods A finite element model of the L1–S1 segment was modified to simulate PLIF with total laminectomy (PLIF-LAM) and PLIF with hemilaminectomy (PLIF-HEMI) procedures. The models were subjected to a 400N follower load with a 7.5-N.m moment of flexion, extension, torsion, and lateral bending. The range of motion (ROM), intradiscal pressure (IDP), and ligament force were compared. Results In Flexion, the ROM, IDP and ligament force of posterior longitudinal ligament, intertransverse ligament, and capsular ligament remarkably increased at the proximal adjacent segment in the PLIF-LAM model, and slightly increased in the PLIF-HEMI model. There was almost no difference for the ROM, IDP and ligament force at L5-S1 level between the two PLIF models although the ligament forces of ligamenta flava remarkably increased compared with the intact lumbar spine (INT) model. For the other loading conditions, these two models almost showed no difference in ROM, IDP and ligament force on the adjacent discs. Conclusions Preserved posterior complex acts as the posterior tension band during PLIF surgery and results in less ROM, IDP and ligament forces on the proximal adjacent segment in flexion. Preserving the posterior complex during decompression can be effective on preventing adjacent segment degeneration (ASD) following PLIF surgeries. PMID:27870867

  14. Biomechanical Analysis of Fusion Segment Rigidity Upon Stress at Both the Fusion and Adjacent Segments: A Comparison between Unilateral and Bilateral Pedicle Screw Fixation

    PubMed Central

    Kim, Ho-Joong; Kang, Kyoung-Tak; Chang, Bong-Soon; Lee, Choon-Ki; Kim, Jang-Woo

    2014-01-01

    Purpose The purpose of this study was to investigate the effects of unilateral pedicle screw fixation on the fusion segment and the superior adjacent segment after one segment lumbar fusion using validated finite element models. Materials and Methods Four L3-4 fusion models were simulated according to the extent of decompression and the method of pedicle screws fixation in L3-4 lumbar fusion. These models included hemi-laminectomy with bilateral pedicle screw fixation in the L3-4 segment (BF-HL model), total laminectomy with bilateral pedicle screw fixation (BF-TL model), hemi-laminectomy with unilateral pedicle screw fixation (UF-HL model), and total laminectomy with unilateral pedicle screw fixation (UF-TL model). In each scenario, intradiscal pressures, annulus stress, and range of motion at the L2-3 and L3-4 segments were analyzed under flexion, extension, lateral bending, and torsional moments. Results Under four pure moments, the unilateral fixation leads to a reduction in increment of range of motion at the adjacent segment, but larger motions were noted at the fusion segment (L3-4) in the unilateral fixation (UF-HL and UF-TL) models when compared to bilateral fixation. The maximal von Mises stress showed similar patterns to range of motion at both superior adjacent L2-3 segments and fusion segment. Conclusion The current study suggests that unilateral pedicle screw fixation seems to be unable to afford sufficient biomechanical stability in case of bilateral total laminectomy. Conversely, in the case of hemi-laminectomy, unilateral fixation could be an alternative option, which also has potential benefit to reduce the stress of the adjacent segment. PMID:25048501

  15. Fusion angle affects intervertebral adjacent spinal segment joint forces-Model-based analysis of patient specific alignment.

    PubMed

    Senteler, Marco; Weisse, Bernhard; Rothenfluh, Dominique A; Farshad, Mazda T; Snedeker, Jess G

    2017-01-01

    This study addresses the hypothesis that adjacent segment intervertebral joint loads are sensitive to the degree of lordosis that is surgically imposed during vertebral fusion. Adjacent segment degeneration is often observed after lumbar fusion, but a causative mechanism is not yet clearly evident. Altered kinematics of the adjacent segments and potentially nonphysiological mechanical joint loads have been implicated in this process. However, little is known of how altered alignment and kinematics influence loading of the adjacent intervertebral joints under consideration of active muscle forces. This study investigated these effects by simulating L4/5 fusions using kinematics-driven musculoskeletal models of one generic and eight sagittal alignment-specific models. Models featured different spinopelvic configurations but were normalized by body height, masses, and muscle properties. Fusion of the L4/5 segment was implemented in an in situ (22°), hyperlordotic (32°), and hypolordotic (8°) fashion and kinematic input parameters were changed accordingly based on findings of an in vitro investigation. Bending motion from upright standing to 45° forward flexion and back was simulated for all models in intact and fused conditions. Joint loads at adjacent levels and moment arms of spinal muscles experienced changes after all types of fusion. Hypolordotic configuration led to an increase of adjacent segment (L3/4) shear forces of 29% on average, whereas hyperlordotic fusion reduced shear by 39%. Overall, L4/5 in situ fusion resulted in intervertebral joint forces closest to intact loading conditions. An artificial decrease in lumbar lordosis (minus 14° on average) caused by an L4/5 fusion lead to adverse loading conditions, particularly at the cranial adjacent levels, and altered muscle moment arms, in particular for muscles in the vicinity of the fusion. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:131-139, 2017.

  16. A dynamic bundle of four adjacent hydrophobic segments in the denatured state of staphylococcal nuclease.

    PubMed Central

    Wang, Y.; Shortle, D.

    1996-01-01

    In an earlier study of the denatured state of staphylococcal nuclease (Wang Y, Shortle D, 1995, Biochemistry 34:15895-15905), we reported evidence of a three-strand antiparallel beta sheet that persists at high urea concentrations and is stabilized by a local "non-native" interaction with four large hydrophobic residues. Because the amide proton resonances for all of the involved residues are severely broadened, this unusual structure is not amenable to conventional NMR analysis and must be studied by indirect methods. In this report, we present data that confirm the important role of interactions involving four hydrophobic residues (Leu 36, Leu 37, Leu 38, and Val 39) in stabilizing the structure formed by the chain segments corresponding to beta 1-beta 2-beta 3-h, interactions that are not present in the native state. Glycine substitutions for each of these large hydrophobic residues destabilizes or disrupts this beta structure, as assessed by HN line sharpening and changes in the CD spectrum. The 13C resonances of the carbonyl carbon for several of the residues in this structure indicate conformational dynamics that respond in a complex way to addition of urea or changes in sequence. Studies of hydrogen exchange kinetics in a closely related variant of staphylococcal nuclease demonstrate the absence of the stable hydrogen bonding between the strands expected for a native-like three-strand beta sheet. Instead, the data are more consistent with the three beta strand segments plus the four adjacent hydrophobic residues forming a dynamic, aligned array or bundle held together by hydrophobic interactions. PMID:8880914

  17. In-Depth Analysis on Influencing Factors of Adjacent Segment Degeneration After Cervical Fusion

    PubMed Central

    Yu, Chaojie; Mu, Xiaoping; Wei, Jianxun; Chu, Ye; Liang, Bin

    2016-01-01

    Background To explore the related influencing factors of adjacent segment degeneration (ASD) after cervical discectomy and fusion (ACDF). Material/Methods A retrospective analysis of 263 patients who underwent ACDF was carried out. Cervical x-ray and magnetic resonance imaging (MRI) were required before operation, after operation, and at the last follow-up. General information and some radiographic parameters of all patients were measured and recorded. According to the imaging data, patients were put into one of two groups: non-ASD group and ASD group. The differences between the two groups were compared by t-test and χ2-test, and the related influencing factors of ASD were analyzed by logistic regression. Results In all, 138 patients had imaging ASD. Comparing the age, the postoperative cervical arc chord distance (po-CACD), and the plate to disc distance (PDD) of the two groups, differences were statistically significant (p<0.05). The gender, the fusion segment number, the pre-CACD, the pre-and-po CACD, the preoperative cervical spinal canal ratio, and the upper and lower disc height (DH) showed no statistical difference between the two groups (p>0.05). The results of logistic regression analysis showed that there were significant correlations in the following characteristics: age, postoperative po-CACD, and the PDD (p<0.05). Of all these characteristics, the correlation of age was the highest (R=1.820). Conclusions Age, po-CACD, and PDD were risk factors for ASD after ACDF. The older the operation age, the worse the recovery was of postoperative physiological curvature of cervical spine, and a PDD < 5 mm was more likely to lead to ASD. PMID:27965512

  18. In-Depth Analysis on Influencing Factors of Adjacent Segment Degeneration After Cervical Fusion.

    PubMed

    Yu, Chaojie; Mu, Xiaoping; Wei, Jianxun; Chu, Ye; Liang, Bin

    2016-12-14

    BACKGROUND To explore the related influencing factors of adjacent segment degeneration (ASD) after cervical discectomy and fusion (ACDF). MATERIAL AND METHODS A retrospective analysis of 263 patients who underwent ACDF was carried out. Cervical x-ray and magnetic resonance imaging (MRI) were required before operation, after operation, and at the last follow-up. General information and some radiographic parameters of all patients were measured and recorded. According to the imaging data, patients were put into one of two groups: non-ASD group and ASD group. The differences between the two groups were compared by t-test and χ²-test, and the related influencing factors of ASD were analyzed by logistic regression. RESULTS In all, 138 patients had imaging ASD. Comparing the age, the postoperative cervical arc chord distance (po-CACD), and the plate to disc distance (PDD) of the two groups, differences were statistically significant (p<0.05). The gender, the fusion segment number, the pre-CACD, the pre-and-po CACD, the preoperative cervical spinal canal ratio, and the upper and lower disc height (DH) showed no statistical difference between the two groups (p>0.05). The results of logistic regression analysis showed that there were significant correlations in the following characteristics: age, postoperative po-CACD, and the PDD (p<0.05). Of all these characteristics, the correlation of age was the highest (R=1.820). CONCLUSIONS Age, po-CACD, and PDD were risk factors for ASD after ACDF. The older the operation age, the worse the recovery was of postoperative physiological curvature of cervical spine, and a PDD < 5 mm was more likely to lead to ASD.

  19. Apparatus and methods for impingement cooling of an undercut region adjacent a side wall of a turbine nozzle segment

    DOEpatents

    Burdgick, Steven Sebastian; Itzel, Gary Michael

    2001-01-01

    A gas turbine nozzle segment has outer and inner bands. Each band includes a side wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through apertures of the impingement plate to cool the nozzle wall. The side wall of the band and inturned flange define with the nozzle wall an undercut region. The inturned flange has a plurality of apertures for directing cooling steam to cool the side wall between adjacent nozzle segments.

  20. Precordial ST segment depression during acute inferior myocardial infarction: early thallium-201 scintigraphic evidence of adjacent posterolateral or inferoseptal involvement

    SciTech Connect

    Lew, A.S.; Weiss, A.T.; Shah, P.K.; Maddahi, J.; Peter, T.; Ganz, W.; Swan, H.J.; Berman, D.S.

    1985-02-01

    To investigate the myocardial perfusion correlates of precordial ST segment depression during acute inferior myocardial infarction, a rest thallium-201 scintigram and a closely timed 12 lead electrocardiogram were obtained within 6 hours of the onset of infarction in 44 patients admitted with their first acute inferior myocardial infarction. Thirty-six patients demonstrated precordial ST segment depression (group 1) and eight did not (group 2). A perfusion defect involving the inferior wall was present in all 44 patients. Additional perfusion defects of the adjacent posterolateral wall (n . 20), the ventricular septum (n . 9) or both (n . 6) were present in 35 of 36 patients from group 1 compared with only 1 of 8 patients from group 2 (p less than 0.001). There was no significant difference in the frequency of multivessel coronary artery disease or disease of the left anterior descending artery between group 1 and group 2 or between patients with and those without a thallium-201 perfusion defect involving the ventricular septum. Thus, precordial ST segment depression during an acute inferior myocardial infarction is associated with thallium-201 scintigraphic evidence of more extensive involvement of the adjacent posterolateral or inferoseptal myocardial segments, which probably reflects the extent and pattern of distribution of the artery of infarction, rather than the presence of coexistent multivessel coronary artery disease or disease of the left anterior descending artery.

  1. Concatemeric intermediates of equine herpesvirus type 1 DNA replication contain frequent inversions of adjacent long segments of the viral genome.

    PubMed

    Slobedman, B; Simmons, A

    1997-03-17

    In common with other alpha-herpesviruses, the genome of equine herpesvirus type-1 (EHV-1) comprises covalently linked long and short unique sequences of DNA, each flanked by inverted repeats. Equimolar amounts of two genomic isomers, generated by free inversion of the short segment, relative to the long segment, are packaged into EHV-1 virions. In contrast with herpes simplex virus (HSV), inversion of genomic long segments has not been described. In the current work, the structures of high molecular weight intermediates of EHV-1 DNA replication were studied by field inversion gel electrophoresis. It is shown that adjacent long segments of the viral genome are frequently inverted in concatemeric intermediates of EHV-1 DNA replication. Further, like HSV concatemers, high molecular weight intermediates of EHV-1 replication are flanked exclusively by the long segment of the viral genome. Hence, despite the fact that only two, rather than four, isomers of EHV-1 DNA are packaged into virions, the intermediates of EHV-1 DNA replication closely resemble those of herpes simplex virus type 1 in structure. These data have implications relating to the mechanisms involved in packaging of alpha-herpesvirus DNA.

  2. Biomechanics of Degenerative Spinal Disorders

    PubMed Central

    Iorio, Justin A.; Jakoi, Andre M.

    2016-01-01

    The spine has several important functions including load transmission, permission of limited motion, and protection of the spinal cord. The vertebrae form functional spinal units, which represent the smallest segment that has characteristics of the entire spinal column. Discs and paired facet joints within each functional unit form a three-joint complex between which loads are transmitted. Surrounding the spinal motion segment are ligaments, composed of elastin and collagen, and joint capsules which restrict motion to within normal limits. Ligaments have variable strengths and act via different lever arm lengths to contribute to spinal stability. As a consequence of the longer moment arm from the spinous process to the instantaneous axis of rotation, inherently weaker ligaments (interspinous and supraspinous) are able to provide resistance to excessive flexion. Degenerative processes of the spine are a normal result of aging and occur on a spectrum. During the second decade of life, the intervertebral disc demonstrates histologic evidence of nucleus pulposus degradation caused by reduced end plate blood supply. As disc height decreases, the functional unit is capable of an increased range of axial rotation which subjects the posterior facet capsules to greater mechanical loads. A concurrent change in load transmission across the end plates and translation of the instantaneous axis of rotation further increase the degenerative processes at adjacent structures. The behavior of the functional unit is impacted by these processes and is reflected by changes in the stress-strain relationship. Back pain and other clinical symptoms may occur as a result of the biomechanical alterations of degeneration. PMID:27114783

  3. Minimally invasive procedure reduces adjacent segment degeneration and disease: New benefit-based global meta-analysis

    PubMed Central

    Li, Xiao-Chuan; Huang, Chun-Ming; Zhong, Cheng-Fan; Liang, Rong-Wei; Luo, Shao-Jian

    2017-01-01

    Objective Adjacent segment pathology (ASP) is a common complication presenting in patients with axial pain and dysfunction, requiring treatment or follow-up surgery. However, whether minimally invasive surgery (MIS), including MIS transforaminal / posterior lumbar interbody fusion (MIS-TLIF/PLIF) decreases the incidence rate of ASP remains unknown. The aim of this meta-analysis was to compare the incidence rate of ASP in patients undergoing MIS versus open procedures. Methods This systematic review was undertaken by following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement. We searched electronic databases, including PubMed, EMBASE, SinoMed, and the Cochrane Library, without language restrictions, to identify clinical trials comparing MIS to open procedures. The results retrieved were last updated on June 15, 2016. Results Overall, 9 trials comprising 770 patients were included in the study; the quality of the studies included 4 moderate and 5 low-quality studies. The pooled data analysis demonstrated low heterogeneity between the trials and a significantly lower ASP incidence rate in patients who underwent MIS procedure, compared with those who underwent open procedure (p = 0.0001). Single-level lumbar interbody fusion was performed in 6 trials of 408 patients and we found a lower ASP incidence rate in MIS group, compared with those who underwent open surgery (p = 0.002). Moreover, the pooled data analysis showed a significant reduction in the incidence rate of adjacent segment disease (ASDis) (p = 0.0003) and adjacent segment degeneration (ASDeg) (p = 0.0002) for both procedures, favoring MIS procedure. Subgroup analyses showed no difference in follow-up durations between the procedures (p = 0.93). Conclusion Therefore, we conclude that MIS-TLIF/PLIF can reduce the incidence rate of ASDis and ASDeg, compared with open surgery. Although the subgroup analysis did not indicate a difference in follow-up duration between the two

  4. Apparatus for impingement cooling a side wall adjacent an undercut region of a turbine nozzle segment

    DOEpatents

    Burdgick, Steven Sebastian

    2002-01-01

    A gas turbine nozzle segment has outer and inner bands and vanes therebetween. Each band includes a side wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through apertures of the impingement plate to cool the nozzle wall. The side wall of the band and inturned flange define with the nozzle wall an undercut region. Slots are formed through the inturned flange along the nozzle side wall. A plate having through-apertures extending between opposite edges thereof is disposed in each slot, the slots and plates being angled such that the cooling medium exiting the apertures in the second cavity lie close to the side wall for focusing and targeting cooling medium onto the side wall.

  5. Enhancement of Lumbar Fusion and Alleviation of Adjacent Segment Disc Degeneration by Intermittent PTH(1-34) in Ovariectomized Rats.

    PubMed

    Zhou, Zhuang; Tian, Fa-Ming; Gou, Yu; Wang, Peng; Zhang, Heng; Song, Hui-Ping; Shen, Yong; Zhang, Ying-Ze; Zhang, Liu

    2016-04-01

    Osteoporosis, which is prevalent in postmenopausal or aged populations, is thought to be a contributing factor to adjacent segment disc degeneration (ASDD), and the incidence and extent of ASDD may be augmented by osteopenia. Parathyroid hormone (PTH) (1-34) has already been shown to be beneficial in osteoporosis, lumbar fusion and matrix homeostasis of intervertebral discs. However, whether PTH(1-34) has a reversing or retarding effect on ASDD in osteopenia has not been confirmed. In the present study, we evaluated the effects of intermittent PTH(1-34) on ASDD in an ovariectomized (OVX) rat model. One hundred 3-month-old female Sprague-Dawley rats underwent L4 -L5 posterolateral lumbar fusion (PLF) with spinous-process wire fixation 4 weeks after OVX surgery. Control groups were established accordingly. PTH(1-34) was intermittently administered immediately after PLF surgery and lasted for 8 weeks using the following groups (n = 20) (V = vehicle): Sham+V, OVX+V, Sham+PLF+V, OVX+PLF+V, OVX+PLF+PTH. The fused segments showed clear evidence of eliminated motion on the fusion-segment based on manual palpation. Greater new bone formation in histology was observed in PTH-treated animals compared to the control group. The extent of ASDD was significantly increased by ovariotomy. Intermittent PTH(1-34) significantly alleviated ASDD by preserving disc height, microvessel density, relative area of vascular buds, endplate thickness and the relative area of endplate calcification. Moreover, protein expression results showed that PTH(1-34) not only inhibited matrix degradation by decreasing MMP-13, ADAMTS-4 and Col-I, but also promote matrix synthesis by increasing Col-II and Aggrecan. In conclusion, PTH(1-34), which effectively improves lumbar fusion and alleviates ASDD in ovariectomized rats, may be a potential candidate to ameliorate the prognosis of lumbar fusion in osteopenia.

  6. Minimally Invasive Unilateral vs. Bilateral Pedicle Screw Fixation and Lumbar Interbody Fusion in Treatment of Multi-Segment Lumbar Degenerative Disorders

    PubMed Central

    Liu, Xiaoyang; Li, Guangrun; Wang, Jiefeng; Zhang, Heqing

    2015-01-01

    Background The choice for instrumentation with minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) in treatment of degenerative lumbar disorders (DLD) remains controversial. The goal of this study was to investigate clinical outcomes in consecutive patients with multi-segment DLD treated with unilateral pedicle screw (UPS) vs. bilateral pedicle screw (BPS) instrumented TLIF. Material/Methods Eighty-four consecutive patients who had multi-level MIS-TLIF were retrospectively reviewed. All data were collected to compare the clinical outcomes between the 2 groups. Results Both groups showed similar clinical function scores in VAS and ODI. The two groups differed significantly in operative time (P<0.001), blood loss (P<0.001), and fusion rate (P=0.043), respectively. Conclusions This study demonstrated similar clinical outcomes between UPS fixation and BPS procedure after MIS-TLIF for multi-level DLD. Moreover, UPS technique was superior in operative time and blood loss, but represented lower fusion rate than the BPS construct did. PMID:26603050

  7. Dike Interactions along the East Pacific Rise: Can Dike-Induced Static Stress Changes Trigger Diking at Adjacent Ridge Segments?

    NASA Astrophysics Data System (ADS)

    Applebee, G. M.; Cormier, M.

    2008-12-01

    Although the physical conditions that control dike intrusion at spreading centers are subject to debate, it is generally agreed these include a crustal section stressed close to failure and an overpressured magma chamber. Along the East Pacific Rise (EPR), fast spreading rates (100-150 mm/yr) and the presence of a narrow, shallow and nearly continuous melt lens (0.5-1.5 km wide, 1-1.5 km deep) imply that these two criteria are frequently met. Hence, a small incremental stress change at the EPR axis may be sufficient to trigger dike intrusion along a "4rth-order segment"- the elemental 10-20 km-long section of ridge that ruptures in a given volcanic episode. We use the COULOMB 3.1 software to investigate whether static stress changes induced by dike emplacement at a 4rth-order segment may be sufficient to trigger diking at neighboring segments. In the absence of any observational data about dike triggering, we adopt some conclusions from studies of stress transfer in earthquake sequences, and assume that static stress changes of 1-2 bar can promote dike intrusion in a favorably pre-stressed crust. Modeling results indicate that tensile stress changes of 1-2 bars extend as far as 10 km beyond the tip of a newly emplaced dike, suggesting that along the EPR, the intrusion of a dike may be sufficient to promote concomitant diking at adjacent 4rth-order segments. This 10 km distance varies only slightly when experimenting with reasonable dike geometries: dike heights of 1-1.5 km and widths of 0.5-2 m are used, as narrowly constrained from observations at the EPR. Hence, provided that a second-order segment (50 km-long or more) is critically stressed and that the subjacent magma chamber is overpressured, eruption of a 4rth-order segment somewhere along that segment may trigger a sequence of diking events on a relatively short time-scale. This model may soon be tested at the EPR "Integrated Study Site" at 9N, by a series of recent and on-going experiments funded by the NSF

  8. Survival Rates and Risk Factors for Cephalad and L5-S1 Adjacent Segment Degeneration after L5 Floating Lumbar Fusion : A Minimum 2-Year Follow-Up

    PubMed Central

    Lee, Young-Seok; Park, Seung-Won

    2015-01-01

    Objective Although the L5-S1 has distinct structural features in comparison with other lumbar spine segments, not much is known about adjacent segment degeneration (ASD) at the L5-S1 segment. The aim of study was to compare the incidence and character of ASD of the cephalad and L5-S1 segments after L5 floating lumbar fusion. Methods From 2005 to 2010, 115 patients who underwent L5 floating lumber fusion were investigated. The mean follow-up period was 46.1 months. The incidence of radiological and clinical ASD of the cephalad and the L5-S1 segments was compared using survival analysis. Risk factors affecting ASD were analyzed using a log rank test and the Cox proportional hazard model. Results Radiological ASD of the L5-S1 segment had a statistically significant higher survival rate than that of the cephalad segment (p=0.001). However, clinical ASD of the L5-S1 segment was significantly lower survival rates than that of the cephalad segment (p=0.038). Risk factor analysis showed that disc degeneration of the cephalad segment and preoperative spinal stenosis of the L5-S1 segment were risk factors. Conclusion In L5 floating fusion, radiological ASD was more common in the cephalad segment and clinical ASD was more common in the L5-S1 segment. At the L5-S1 segment, the degree of spinal stenosis appears to be the most influential risk factor in ASD incidences, unlike the cephalad segment. PMID:25733991

  9. Flexible Stabilisation of the Degenerative Lumbar Spine Using PEEK Rods

    PubMed Central

    Benezech, Jacques; Garlenq, Bruno; Larroque, Gilles

    2016-01-01

    Posterior lumbar interbody fusion using cages, titanium rods, and pedicle screws is considered today as the gold standard of surgical treatment of lumbar degenerative disease and has produced satisfying long-term fusion rates. However this rigid material could change the physiological distribution of load at the instrumental and adjacent segments, a main cause of implant failure and adjacent segment disease, responsible for a high rate of further surgery in the following years. More recently, semirigid instrumentation systems using rods made of polyetheretherketone (PEEK) have been introduced. This clinical study of 21 patients focuses on the clinical and radiological outcomes of patients with lumbar degenerative disease treated with Initial VEOS PEEK®-Optima system (Innov'Spine, France) composed of rods made from PEEK-OPTIMA® polymer (Invibio Biomaterial Solutions, UK) without arthrodesis. With an average follow-up of 2 years and half, the chances of reoperation were significantly reduced (4.8%), quality of life was improved (ODI = 16%), and the adjacent disc was preserved in more than 70% of cases. Based on these results, combined with the biomechanical and clinical data already published, PEEK rods systems can be considered as a safe and effective alternative solution to rigid ones. PMID:26981285

  10. Flexible Stabilisation of the Degenerative Lumbar Spine Using PEEK Rods.

    PubMed

    Benezech, Jacques; Garlenq, Bruno; Larroque, Gilles

    2016-01-01

    Posterior lumbar interbody fusion using cages, titanium rods, and pedicle screws is considered today as the gold standard of surgical treatment of lumbar degenerative disease and has produced satisfying long-term fusion rates. However this rigid material could change the physiological distribution of load at the instrumental and adjacent segments, a main cause of implant failure and adjacent segment disease, responsible for a high rate of further surgery in the following years. More recently, semirigid instrumentation systems using rods made of polyetheretherketone (PEEK) have been introduced. This clinical study of 21 patients focuses on the clinical and radiological outcomes of patients with lumbar degenerative disease treated with Initial VEOS PEEK(®)-Optima system (Innov'Spine, France) composed of rods made from PEEK-OPTIMA(®) polymer (Invibio Biomaterial Solutions, UK) without arthrodesis. With an average follow-up of 2 years and half, the chances of reoperation were significantly reduced (4.8%), quality of life was improved (ODI = 16%), and the adjacent disc was preserved in more than 70% of cases. Based on these results, combined with the biomechanical and clinical data already published, PEEK rods systems can be considered as a safe and effective alternative solution to rigid ones.

  11. Causes of long-term landscape evolution of "passive" margins and adjacent continental segments at the South Atlantic Ocean.

    NASA Astrophysics Data System (ADS)

    Glasmacher, Ulrich Anton; Hackspacher, Peter C.

    2013-04-01

    During the last 10 years research efforts have been devoted to understand the coupling between tectonic and surface processes in the formation of recent topography. Quantification of the rate at which landforms adapt to a changing tectonic, heat flow, and climate environment in the long term has become an important research object and uses intensively data revealed by low-temperature thermochronology, terrigenous cosmogenic nuclides, and geomorphological analyses. The influence of endogenic forces such as mantle processes as one of the causes for "Dynamic Topography Evolution" have been explored in a few studies, recently. In addition, the increased understanding how change in surface topography, and change in the amount of downward moving cold surface water caused by climate change affects warping isotherms in the uppermost crust allows further interpretation of low-temperature thermochronological data. "Passive" continental margins and adjacent continental segments especially at the South Atlantic ocean are perfect locations to quantify exhumation and uplift rates, model the long-term landscape evolution, and provide information on the influence of mantle processes on a longer time scale. This climate-continental margin-mantle process-response system is caused by the interaction between endogenic and exogenic forces that are related to the mantle-process driven rift - drift - "passive" continental margin evolution of the South Atlantic, and the climate change since the Early/Late Cretaceous climate maximum. Furthermore, the influence of major transform faults (also called: transfer zones, Fracture Zones (FZ)) on the long-term evolution of "passive" continental margins is still very much in debate. The presentation will provide insight in possible causes for the differentiated long-term landscape evolution along the South Atlantic Ocean.

  12. Decisive factor in increase of loading at adjacent segments after lumbar fusion: operative technique, pedicle screws, or fusion itself: biomechanical analysis using finite element

    NASA Astrophysics Data System (ADS)

    Park, Joon-Hee; Kim, Ho-Joong; Kang, Kyoung-Tak; Kim, Ka-Yeon; Chun, Heoung-Jae; Moon, Seong-Hwan; Lee, Hwan-Mo

    2009-12-01

    The aim of this study is to investigate the change in biomechanical milieu following removal of pedicle screws or removal of spinous process with posterior ligament complex in instrumented single level lumbar arthrodesis. We developed and validated a finite element model (FEM) of the intact lumbar spine (L2-4). Four scenarios of L3-4 lumbar fusion were simulated: posterolateral fusion (PLF) at L3-4 using pedicle screw system with preservation of PLC (Pp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system with preservation of PLC (Pp WoP), L3-4 using pedicle screw system without preservation PLC (Sp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system without preservation of PLC (Sp WoP). For these models, we investigated the range of motion and maximal Von mises stress of disc in all segments under various moments. All fusion models demonstrated increase in range of motion at adjacent segments compared to the intact model.For the four fusion models, the WiP model s P had the largest increase in range of motion at each adjacent segment. This study demonstrated that removal of pedicle screw system and preservation of PLC after complete lumbar spinal fusion could reduce the stress of adjacent segments synergistically and might have beneficial effects in preventing ASD.

  13. Decisive factor in increase of loading at adjacent segments after lumbar fusion: operative technique, pedicle screws, or fusion itself: biomechanical analysis using finite element

    NASA Astrophysics Data System (ADS)

    Park, Joon-Hee; Kim, Ho-Joong; Kang, Kyoung-Tak; Kim, Ka-yeon; Chun, Heoung-Jae; Moon, Seong-Hwan; Lee, Hwan-Mo

    2010-03-01

    The aim of this study is to investigate the change in biomechanical milieu following removal of pedicle screws or removal of spinous process with posterior ligament complex in instrumented single level lumbar arthrodesis. We developed and validated a finite element model (FEM) of the intact lumbar spine (L2-4). Four scenarios of L3-4 lumbar fusion were simulated: posterolateral fusion (PLF) at L3-4 using pedicle screw system with preservation of PLC (Pp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system with preservation of PLC (Pp WoP), L3-4 using pedicle screw system without preservation PLC (Sp WiP), L3-4 lumbar posterolateral fusion state after removal of pedicle screw system without preservation of PLC (Sp WoP). For these models, we investigated the range of motion and maximal Von mises stress of disc in all segments under various moments. All fusion models demonstrated increase in range of motion at adjacent segments compared to the intact model.For the four fusion models, the WiP model s P had the largest increase in range of motion at each adjacent segment. This study demonstrated that removal of pedicle screw system and preservation of PLC after complete lumbar spinal fusion could reduce the stress of adjacent segments synergistically and might have beneficial effects in preventing ASD.

  14. Morphologic alterations of the subchondral bone in advanced degenerative arthritis.

    PubMed

    Milgram, J W

    1983-03-01

    A series of 535 femoral heads surgically excised at the time of total hip arthroplasty for degenerative arthritis were analyzed by gross photography, specimen roentgenograms, and whole-mount histologic sections. Limited regenerative capacity was apparent in the chondrous tufts in the exposed bone of the osteoarthritic joint surface. The mechanism for the formation of subchondral cysts was interpreted to be the proliferation of viable myxomatous cells within the bone marrow. Osseous remodeling adjacent to the cysts was secondary to expansion of the soft tissue contents of the early cysts and later vascularization with fibrosis in the older cysts. Stress fracturing was a focal feature secondary to the remodeling of live bone. Advanced degenerative arthritis demonstrated focal osteocytic necrosis in the exposed osseous surface. Bone necrosis was also observed when small segments of the surface were undermined by cysts. Finally, bone necrosis was occasionally observed as focal infarcts of the joint surface (2-6 mm). In all three instances, bone necrosis in degenerative arthritis appeared to be a secondary reaction, presumably related to local disruption of blood supply.

  15. Changes in the Expressions of Iba1 and Calcitonin Gene-Related Peptide in Adjacent Lumbar Spinal Segments after Lumbar Disc Herniation in a Rat Model.

    PubMed

    Cho, Hee Kyung; Ahn, Sang Ho; Kim, So-Yeon; Choi, Mi-Jung; Hwang, Se Jin; Cho, Yun Woo

    2015-12-01

    Lumbar disc herniation is commonly encountered in clinical practice and can induce sciatica due to mechanical and/or chemical irritation and the release of proinflammatory cytokines. However, symptoms are not confined to the affected spinal cord segment. The purpose of this study was to determine whether multisegmental molecular changes exist between adjacent lumbar spinal segments using a rat model of lumbar disc herniation. Twenty-nine male Sprague-Dawley rats were randomly assigned to either a sham-operated group (n=10) or a nucleus pulposus (NP)-exposed group (n=19). Rats in the NP-exposed group were further subdivided into a significant pain subgroup (n=12) and a no significant pain subgroup (n=7) using mechanical pain thresholds determined von Frey filaments. Immunohistochemical stainings of microglia (ionized calcium-binding adapter molecule 1; Iba1), astrocytes (glial fibrillary acidic protein; GFAP), calcitonin gene-related peptide (CGRP), and transient receptor potential vanilloid 1 (TRPV1) was performed in spinal dorsal horns and dorsal root ganglions (DRGs) at 10 days after surgery. It was found immunoreactivity for Iba1-positive microglia was higher in the L5 (P=0.004) dorsal horn and in the ipsilateral L4 (P=0.009), L6 (P=0.002), and S1 (P=0.002) dorsal horns in the NP-exposed group than in the sham-operated group. The expression of CGRP was also significantly higher in ipsilateral L3, L4, L6, and S1 segments and in L5 DRGs at 10 days after surgery in the NP-exposed group than in the sham-operated group (P<0.001). Our results indicate that lumbar disc herniation upregulates microglial activity and CGRP expression in many adjacent and ipsilateral lumbar spinal segments.

  16. Changes in the Expressions of Iba1 and Calcitonin Gene-Related Peptide in Adjacent Lumbar Spinal Segments after Lumbar Disc Herniation in a Rat Model

    PubMed Central

    2015-01-01

    Lumbar disc herniation is commonly encountered in clinical practice and can induce sciatica due to mechanical and/or chemical irritation and the release of proinflammatory cytokines. However, symptoms are not confined to the affected spinal cord segment. The purpose of this study was to determine whether multisegmental molecular changes exist between adjacent lumbar spinal segments using a rat model of lumbar disc herniation. Twenty-nine male Sprague-Dawley rats were randomly assigned to either a sham-operated group (n=10) or a nucleus pulposus (NP)-exposed group (n=19). Rats in the NP-exposed group were further subdivided into a significant pain subgroup (n=12) and a no significant pain subgroup (n=7) using mechanical pain thresholds determined von Frey filaments. Immunohistochemical stainings of microglia (ionized calcium-binding adapter molecule 1; Iba1), astrocytes (glial fibrillary acidic protein; GFAP), calcitonin gene-related peptide (CGRP), and transient receptor potential vanilloid 1 (TRPV1) was performed in spinal dorsal horns and dorsal root ganglions (DRGs) at 10 days after surgery. It was found immunoreactivity for Iba1-positive microglia was higher in the L5 (P=0.004) dorsal horn and in the ipsilateral L4 (P=0.009), L6 (P=0.002), and S1 (P=0.002) dorsal horns in the NP-exposed group than in the sham-operated group. The expression of CGRP was also significantly higher in ipsilateral L3, L4, L6, and S1 segments and in L5 DRGs at 10 days after surgery in the NP-exposed group than in the sham-operated group (P<0.001). Our results indicate that lumbar disc herniation upregulates microglial activity and CGRP expression in many adjacent and ipsilateral lumbar spinal segments. PMID:26713069

  17. Fifth lumbar spinal nerve injury causes neurochemical changes in corresponding as well as adjacent spinal segments: a possible mechanism underlying neuropathic pain.

    PubMed

    Shehab, Safa Al-Deen Saudi

    2014-01-01

    Previous investigations of the anatomical basis of the neuropathic-like manifestations in the spinal nerve ligation animal model have shown that the central terminations of the unmyelinated primary afferents of L5 spinal nerve are not restricted to the corresponding L5 spinal segment, and rather extend to two spinal segments rostrally and one segment caudally where they intermingle with primary afferents of the adjacent L4 spinal nerve. The aim of the present study was to investigate the neurochemical changes in the dorsal horn of the spinal cord and DRGs after L5 nerve injury in rats. In the first experiment, the right L5 nerve was ligated and sectioned for 14 days, and isolectin B4 (IB4, a tracer for unmyelinated primary afferents) was injected into the left L5 nerve. The results showed that the vasoactive intestinal peptide (VIP) was up-regulated in laminae I-II of L3-L6 spinal segments on the right side in exactly the same areas where IB4 labelled terminals were revealed on the left side. In the second experiment, L5 was ligated and sectioned and the spinal cord and DRGs were stained immunocytochemically with antibodies raised against various peptides known to be involved in pain transmission and hyperalgesia. The results showed that L5 nerve lesion caused down-regulation of substance P, calcitonin-gene related peptide and IB4 binding and up-regulation of neuropeptide Y and neurokinin-1 receptor in the dorsal horn of L4 and L5 spinal segments. Similar neurochemical changes were observed only in the corresponding L5 DRG with minimal effects observed in L3, L4 and L6 DRGs. Although, L5 nerve injury caused an up-regulation in NPY, no change in SP and CGRP immunoreactivity was observed in ipsilateral garcile nucleus. These neuroplastic changes in the dorsal horn of the spinal cord, in the adjacent uninjured territories of the central terminations of the adjacent uninjured nerves, might explain the mechanism of hyperalgesia after peripheral nerve injury.

  18. Comparison of the Dynesys Dynamic Stabilization System and Posterior Lumbar Interbody Fusion for Lumbar Degenerative Disease

    PubMed Central

    Zhang, Yang; Shan, Jian-Lin; Liu, Xiu-Mei; Li, Fang; Guan, Kai; Sun, Tian-Sheng

    2016-01-01

    Background There have been few studies comparing the clinical and radiographic outcomes between the Dynesys dynamic stabilization system and posterior lumbar interbody fusion (PLIF). The objective of this study is to compare the clinical and radiographic outcomes of Dynesys and PLIF for lumbar degenerative disease. Methods Of 96 patients with lumbar degenerative disease included in this retrospectively analysis, 46 were treated with the Dynesys system and 50 underwent PLIF from July 2008 to March 2011. Clinical and radiographic outcomes were evaluated. We also evaluated the occurrence of radiographic and symptomatic adjacent segment degeneration (ASD). Results The mean follow-up time in the Dynesys group was 53.6 ± 5.3 months, while that in the PLIF group was 55.2 ± 6.8 months. At the final follow-up, the Oswestry disability index and visual analogue scale score were significantly improved in both groups. The range of motion (ROM) of stabilized segments in Dynesys group decreased from 7.1 ± 2.2° to 4.9 ± 2.2° (P < 0.05), while that of in PLIF group decreased from 7.3 ± 2.3° to 0° (P < 0.05). The ROM of the upper segments increased significantly in both groups at the final follow-up, the ROM was higher in the PLIF group. There were significantly more radiographic ASDs in the PLIF group than in the Dynesys group. The incidence of complications was comparable between groups. Conclusions Both Dynesys and PLIF can improve the clinical outcomes for lumbar degenerative disease. Compared to PLIF, Dynesys stabilization partially preserves the ROM of the stabilized segments, limits hypermobility in the upper adjacent segment, and may prevent the occurrence of ASD. PMID:26824851

  19. Somatostatin inhibits activation of dorsal cutaneous primary afferents induced by antidromic stimulation of primary afferents from an adjacent thoracic segment in the rat.

    PubMed

    Guo, Yuan; Yao, Fan-Rong; Cao, Dong-Yuan; Pickar, Joel G; Zhang, Qi; Wang, Hui-Sheng; Zhao, Yan

    2008-09-10

    To investigate the effect of somatostatin on the cross-excitation between adjacent primary afferent terminals in the rats, we recorded single unit activity from distal cut ends of dorsal cutaneous branches of the T10 and T12 spinal nerves in response to antidromic stimulation of the distal cut end of the T11 dorsal root in the presence and absence of somatostatin and its receptor antagonist applied to the receptive field of the recorded nerve. Afferent fibers were classified based upon their conduction velocity. Mean mechanical thresholds decreased and spontaneous discharge rates increased significantly in C and Adelta but not Abeta fibers of the T10 and T12 spinal nerves in both male and female rats following antidromic electrical stimulation (ADES) of the dorsal root from adjacent spinal segment (DRASS) indicating cross-excitation of thin fiber afferents. The cross-excitation was not significantly different between male and female rats. Microinjection of somatostatin into the receptive field of recorded units inhibited the cross-excitation. This inhibitory effect, in turn, was reversed by the somatostation receptor antagonist cyclo-somatostatin (c-SOM). Application of c-SOM alone followed by ADES of DRASS significantly decreased the mechanical thresholds and increased the discharge rates of C and Adelta fibers, indicating that endogenous release of somatostatin plays a tonic inhibitory role on the cross-excitation between peripheral nerves. These results suggest that somatostatin could inhibit the cross-excitation involved in peripheral hyperalgesia and have a peripheral analgesic effect.

  20. Fast inter-mode decision algorithm for high-efficiency video coding based on similarity of coding unit segmentation and partition mode between two temporally adjacent frames

    NASA Astrophysics Data System (ADS)

    Zhong, Guo-Yun; He, Xiao-Hai; Qing, Lin-Bo; Li, Yuan

    2013-04-01

    High-efficiency video coding (HEVC) introduces a flexible hierarchy of three block structures: coding unit (CU), prediction unit (PU), and transform unit (TU), which have brought about higher coding efficiency than the current national video coding standard H.264/advanced video coding (AVC). HEVC, however, simultaneously requires higher computational complexity than H.264/AVC, although several fast inter-mode decisions were proposed in its development. To further reduce this complexity, a fast inter-mode decision algorithm is proposed based on temporal correlation. Because of the distinct difference of inter-prediction block between HEVC and H.264/AVC, in order to use the temporal correlation to speed up the inter prediction, the correlation of inter-prediction between two adjacent frames needs to be analyzed according to the structure of CU and PU in HEVC. The probabilities of all the partition modes in all sizes of CU and the similarity of CU segmentation and partition modes between two adjacent frames are tested. The correlation of partition modes between two CUs with different sizes in two adjacent frames is tested and analyzed. Based on the characteristics tested and analyzed, at most, two prior partition modes are evaluated for each level of CU, which reduces the number of rate distortion cost calculations. The simulation results show that the proposed algorithm further reduces coding time by 33.0% to 43.3%, with negligible loss in bitrate and peak signal-to-noise ratio, on the basis of the fast inter-mode decision algorithms in current HEVC reference software HM7.0.

  1. Complete cage migration/subsidence into the adjacent vertebral body after posterior lumbar interbody fusion.

    PubMed

    Corniola, Marco V; Jägersberg, Max; Stienen, Martin N; Gautschi, Oliver P

    2015-03-01

    A variety of implant-related short and long-term complications after lumbar fusion surgery are recognized. Mid to long-term complications due to cage migration and/or cage subsidence are less frequently reported. Here, we report a patient with a complete cage migration into the superior adjacent vertebral body almost 20 years after the initial posterior lumbar interbody fusion procedure. In this patient, the cage migration/subsidence was clinically silent, but a selective decompression for adjacent segment degenerative lumbar spinal stenosis was performed. We discuss the risk factors for cage migration/subsidence in view of the current literature.

  2. Total Disc Replacement in Lumbar Degenerative Disc Diseases

    PubMed Central

    2015-01-01

    More than 10 years have passed since lumbar total disc replacement (LTDR) was introduced for the first time to the world market for the surgical management of lumbar degenerative disc disease (DDD). It seems like the right time to sum up the relevant results in order to understand where LTDR stands on now, and is heading forward to. The pathogenesis of DDD has been currently settled, but diagnosis and managements are still controversial. Fusion is recognized as golden standard of surgical managements but has various kinds of shortcomings. Lately, LTDR has been expected to replace fusion surgery. A great deal of LTDR reports has come out. Among them, more than 5-year follow-up prospective randomized controlled studies including USA IDE trials were expected to elucidate whether for LTDR to have therapeutic benefit compared to fusion. The results of these studies revealed that LTDR was not inferior to fusion. Most of clinical studies dealing with LTDR revealed that there was no strong evidence for preventive effect of LTDR against symptomatic degenerative changes of adjacent segment disease. LTDR does not have shortcomings associated with fusion. However, it has a potentiality of the new complications to occur, which surgeons have never experienced in fusion surgeries. Consequently, longer follow-up should be necessary as yet to confirm the maintenance of improved surgical outcome and to observe any very late complications. LTDR still may get a chance to establish itself as a substitute of fusion both nominally and virtually if it eases the concerns listed above. PMID:26713139

  3. Arthrodesis to L5 versus S1 in long instrumentation and fusion for degenerative lumbar scoliosis.

    PubMed

    Cho, Kyu-Jung; Suk, Se-Il; Park, Seung-Rim; Kim, Jin-Hyok; Choi, Sung-Wook; Yoon, Young-Hyun; Won, Man-Hee

    2009-04-01

    There is a debate regarding the distal fusion level for degenerative lumbar scoliosis. Whether a healthy L5-S1 motion segment should be included or not in the fusion remains controversial. The purpose of this study was to determine the optimal indication for the fusion to the sacrum, and to compare the results of distal fusion to L5 versus the sacrum in the long instrumented fusion for degenerative lumbar scoliosis. A total of 45 patients who had undergone long instrumentation and fusion for degenerative lumbar scoliosis were evaluated with a minimum 2 year follow-up. Twenty-four patients (mean age 63.6) underwent fusion to L5 and 21 patients (mean age 65.6) underwent fusion to the sacrum. Supplemental interbody fusion was performed in 12 patients in the L5 group and eleven patients in the sacrum group. The number of levels fused was 6.08 segments (range 4-8) in the L5 group and 6.09 (range 4-9) in the sacrum group. Intraoperative blood loss (2,754 ml versus 2,938 ml) and operative time (220 min versus 229 min) were similar in both groups. The Cobb angle changed from 24.7 degrees before surgery to 6.8 degrees after surgery in the L5 group, and from 22.8 degrees to 7.7 degrees in the sacrum group without statistical difference. Correction of lumbar lordosis was statistically better in the sacrum group (P = 0.03). Less correction of lumbar lordosis in the L5 group seemed to be associated with subsequent advanced L5-S1 disc degeneration. The change of coronal and sagittal imbalance was not different in both groups. Subsequent advanced L5-S1 disc degeneration occurred in 58% of the patients in the L5 group. Symptomatic adjacent segment disease at L5-S1 developed in five patients. Interestingly, the development of adjacent segment disease was not related to the preoperative grade of disc degeneration, which proved minimal degeneration in the five patients. In the L5 group, there were nine patients of complications at L5-S1 segment, including adjacent segment disease at

  4. Segments.

    ERIC Educational Resources Information Center

    Zemsky, Robert; Shaman, Susan; Shapiro, Daniel B.

    2001-01-01

    Presents a market taxonomy for higher education, including what it reveals about the structure of the market, the model's technical attributes, and its capacity to explain pricing behavior. Details the identification of the principle seams separating one market segment from another and how student aspirations help to organize the market, making…

  5. Degenerative Nerve Diseases

    MedlinePlus

    Degenerative nerve diseases affect many of your body's activities, such as balance, movement, talking, breathing, and heart function. Many of these diseases are genetic. Sometimes the cause is a medical ...

  6. Hybrid Surgery of Multilevel Cervical Degenerative Disc Disease : Review of Literature and Clinical Results

    PubMed Central

    Lee, Sang-Bok; Kim, Jong-Youn; Yoo, Do-Sung; Lee, Tae-Gyu; Huh, Pil-Woo

    2012-01-01

    Objective In the present study, we evaluated the effect, safety and radiological outcomes of cervical hybrid surgery (cervical disc prosthesis replacement at one level, and interbody fusion at the other level) on the multilevel cervical degenerative disc disease (DDD). Methods Fifty-one patients (mean age 46.7 years) with symptomatic multilevel cervical spondylosis were treated using hybrid surgery (HS). Clinical [neck disability index (NDI) and Visual Analogue Scale (VAS) score] and radiologic outcomes [range of motion (ROM) for cervical spine, adjacent segment and arthroplasty level] were evaluated at routine postoperative intervals of 1, 6, 12, 24 months. Review of other similar studies that examined the HS in multilevel cervical DDD was performed. Results Out of 51 patients, 41 patients received 2 level hybrid surgery and 10 patients received 3 level hybrid surgery. The NDI and VAS score were significantly decreased during the follow up periods (p<0.05). The cervical ROM was recovered at 6 and 12 month postoperatively and the mean ROM of inferior adjacent segment was significantly larger than that of superior adjacent segments after surgery. The ROM of the arthoplasty level was preserved well during the follow up periods. No surgical and device related complications were observed. Conclusion Hybrid surgery is a safe and effective alternative to fusion for the management of multilevel cervical spondylosis. PMID:23323165

  7. Evaluation of Coflex interspinous stabilization following decompression compared with decompression and posterior lumbar interbody fusion for the treatment of lumbar degenerative disease: A minimum 5-year follow-up study.

    PubMed

    Yuan, Wei; Su, Qing-Jun; Liu, Tie; Yang, Jin-Cai; Kang, Nan; Guan, Li; Hai, Yong

    2017-01-01

    Few studies have compared the clinical and radiological outcomes between Coflex interspinous stabilization and posterior lumbar interbody fusion (PLIF) for degenerative lumbar disease. We compared the at least 5-year clinical and radiological outcomes of Coflex stabilization and PLIF for lumbar degenerative disease. Eighty-seven consecutive patients with lumbar degenerative disease were retrospectively reviewed. Forty-two patients underwent decompression and Coflex interspinous stabilization (Coflex group), 45 patients underwent decompression and PLIF (PLIF group). Clinical and radiological outcomes were evaluated. Coflex subjects experienced less blood loss, shorter hospital stays and shorter operative time than PLIF (all p<0.001). Both groups demonstrated significant improvement in Oswestry Disability Index and visual analogue scale back and leg pain at each follow-up time point. The Coflex group had significantly better clinical outcomes during early follow-up. At final follow-up, the superior and inferior adjacent segments motion had no significant change in the Coflex group, while the superior adjacent segment motion increased significantly in the PLIF group. At final follow-up, the operative level motion was significantly decreased in both groups, but was greater in the Coflex group. The reoperation rate for adjacent segment disease was higher in the PLIF group, but this did not achieve statistical significance (11.1% vs. 4.8%, p=0.277). Both groups provided sustainable improved clinical outcomes for lumbar degenerative disease through at least 5-year follow-up. The Coflex group had significantly better early efficacy than the PLIF group. Coflex interspinous implantation after decompression is safe and effective for lumbar degenerative disease.

  8. Clinical and radiologic comparison of dynamic cervical implant arthroplasty versus anterior cervical discectomy and fusion for the treatment of cervical degenerative disc disease.

    PubMed

    Li, Zhonghai; Yu, Shunzhi; Zhao, Yantao; Hou, Shuxun; Fu, Qiang; Li, Fengning; Hou, Tiesheng; Zhong, Hongbin

    2014-06-01

    This study compared the clinical and radiological outcomes of dynamic cervical implant (DCI; Scient'x, Villers-Bretonneux, France) arthroplasty versus anterior cervical discectomy and fusion (ACDF) for the treatment of cervical degenerative disc disease. This prospective cohort study enrolled patients with single-level cervical degenerative disc disease who underwent DCI arthroplasty or ACDF between September 2009 and June 2011. Patients were followed up for more than 2years. Clinical evaluation included the Medical Outcomes Study 36-Item Short Form Health Survey (SF-36), Neck Disability Index (NDI), Japan Orthopedic Association (JOA) score, and visual analog scale (VAS) scores for neck and arm pain. Radiological assessments included segmental range of motion (ROM), overall ROM (C2-C7), disc height (DHI), and changes in adjacent disc spaces. The VAS, SF-36, JOA, and NDI scores improved significantly after surgery in both the DCI and ACDF groups. The VAS, JOA, and SF-36 scores were not significantly different between the DCI and ACDF groups at the final follow-up. The segmental ROM at the treated level and overall ROM increased significantly after surgery in the DCI group, but the ROM in the adjacent cephalad and caudal segments did not change significantly. The mean DHI at the treated level was significantly restored after surgery in both groups. Five patients (12.8%) in the DCI group showed new signs of adjacent segment degeneration. These results indicate that DCI is an effective, reliable, and safe procedure for the treatment of cervical degenerative disc disease. However, there is no definitive evidence that DCI arthroplasty has better intermediate-term results than ACDF.

  9. The degenerative cervical spine.

    PubMed

    Llopis, E; Belloch, E; León, J P; Higueras, V; Piquer, J

    2016-04-01

    Imaging techniques provide excellent anatomical images of the cervical spine. The choice to use one technique or another will depend on the clinical scenario and on the treatment options. Plain-film X-rays continue to be fundamental, because they make it possible to evaluate the alignment and bone changes; they are also useful for follow-up after treatment. The better contrast resolution provided by magnetic resonance imaging makes it possible to evaluate the soft tissues, including the intervertebral discs, ligaments, bone marrow, and spinal cord. The role of computed tomography in the study of degenerative disease has changed in recent years owing to its great spatial resolution and its capacity to depict osseous components. In this article, we will review the anatomy and biomechanical characteristics of the cervical spine, and then we provide a more detailed discussion of the degenerative diseases that can affect the cervical spine and their clinical management.

  10. How Does Lumbar Degenerative Disc Disease Affect the Disc Deformation at the Cephalic Levels In Vivo?

    PubMed Central

    Wang, Shaobai; Xia, Qun; Passias, Peter; Li, Weishi; Wood, Kirkham; Li, Guoan

    2013-01-01

    Study Design Case-control study. Objective . To evaluate the effect of lumbar degenerative disc disease (DDD) on the disc deformation at the adjacent level and at the level one above the adjacent level during end ranges of lumbar motion. Summary of Background Data It has been reported that in patients with DDD, the intervertebral discs adjacent to the diseased levels have a greater tendency to degenerate. Although altered biomechanics have been suggested to be the causative factors, few data have been reported on the deformation characteristics of the adjacent discs in patients with DDD. Methods Ten symptomatic patients with discogenic low back pain between L4 and S1 and with healthy discs at the cephalic segments were involved. Eight healthy subjects recruited in our previous studies were used as a reference comparison. The in vivo kinematics of L3–L4 (the cephalic adjacent level to the degenerated discs) and L2–L3 (the level one above the adjacent level) lumbar discs of both groups were obtained using a combined magnetic resonance imaging and dual fluoroscopic imaging technique at functional postures. Deformation characteristics, in terms of areas of minimal deformation (defined as less than 5%), deformations at the center of the discs, and maximum tensile and shear deformations, were compared between the two groups at the two disc levels. Results In the patients with DDD, there were significantly smaller areas of minimal disc deformation at L3–L4 and L2–L3 than the healthy subjects (18% compared with 45% of the total disc area, on average). Both L2–L3 and L3–L4 discs underwent larger tensile and shear deformations in all postures than the healthy subjects. The maximum tensile deformations were higher by up to 23% (of the local disc height in standing) and the maximum shear deformations were higher by approximately 25% to 40% (of the local disc height in standing) compared with those of the healthy subjects. Conclusion Both the discs of the adjacent

  11. Mid-range outcomes in 64 consecutive cases of multilevel fusion for degenerative diseases of the lumbar spine

    PubMed Central

    Röllinghoff, Marc; Schlüter-Brust, Klaus; Groos, Daniel; Sobottke, Rolf; Michael, Joern William-Patrick; Eysel, Peer; Delank, Karl Stefan

    2010-01-01

    In the treatment of multilevel degenerative disorders of the lumbar spine, spondylodesis plays a controversial role. Most patients can be treated conservatively with success. Multilevel lumbar fusion with instrumentation is associated with severe complications like failed back surgery syndrome, implant failure, and adjacent segment disease (ASD). This retrospective study examines the records of 70 elderly patients with degenerative changes or instability of the lumbar spine treated between 2002 and 2007 with spondylodesis of more than two segments. Sixty-four patients were included; 5 patients had died and one patient was lost to follow-up. We evaluated complications, clinical/radiological outcomes, and success of fusion. Flexion-extension and standing X-rays in two planes, MRI, and/or CT scans were obtained pre-operatively. Patients were assessed clinically using the Oswestry disability index (ODI) and a Visual Analogue Scale (VAS). Surgery performed was dorsolateral fusion (46.9%) or dorsal fusion with anterior lumbar interbody fusion (ALIF; 53.1%). Additional decompression was carried out in 37.5% of patients. Mean follow-up was 29.4±5.4 months. Average patient age was 64.7±4.3 years. Clinical outcomes were not satisfactory for all patients. VAS scores improved from 8.6±1.3 to 5.6±3.0 pre- to post-operatively, without statistical significance. ODI was also not significantly improved (56.1±22.3 pre- and 45.1±26.4 post-operatively). Successful fusion, defined as adequate bone mass with trabeculation at the facets and transverse processes or in the intervertebral segments, did not correlate with good clinical outcomes. Thirty-five of 64 patients (54%) showed signs of pedicle screw loosening, especially of the screws at S1. However, only 7 of these 35 (20%) complained of corresponding back pain. Revision surgery was required in 24 of 64 patients (38%). Of these, indications were adjacent segment disease (16 cases), pedicle screw loosening (7 cases), and

  12. Hybrid surgery versus anterior cervical discectomy and fusion for multilevel cervical degenerative disc diseases: a meta-analysis.

    PubMed

    Tian, Peng; Fu, Xin; Li, Zhi-Jun; Sun, Xiao-Lei; Ma, Xin-Long

    2015-08-26

    The objective of this meta-analysis is to compare hybrid surgery (HS) and cervical discectomy and fusion (ACDF) for multilevel cervical degenerative disc diseases (DDD). Systematic searches of all published studies through March 2015 were identified from Cochrane Library, Medline, PubMed, Embase, ScienceDirect, CNKI, WANFANG DATA and CQVIP. Randomized controlled trials (RCTs) and non-RCTs involving HS and ACDF for multilevel DDD were included. All literature was searched and assessed by two independent reviewers according to the standard of Cochrane systematic review. Data of functional and radiological outcomes in two groups were pooled, which was then analyzed by RevMan 5.2 software. One RCT and four non-RCTs encompassing 160 patients met the inclusion criteria. Meta-analysis revealed significant differences in blood loss (p = 0.005), postoperative C2-C7 ROM (p = 0.002), ROM of superior adjacent segment (p < 0.00001) and ROM of inferior adjacent segment (p = 0.0007) between the HS group and the ACDF group. No significant differences were found regarding operation time (p = 0.75), postoperative VAS (p = 0.18) and complications (p = 0.73) between the groups. Hybrid surgery demonstrated excellent clinical efficacy and radiological results. Postoperative C2-C7 ROM was closer to the physiological status. No decrease in the ROM of the adjacent segment was noted in the hybrid surgery group.

  13. Classification of degenerative arthritis.

    PubMed Central

    Mitchell, N. S.; Cruess, R. L.

    1977-01-01

    It is suggested that the former division of degenerative arthritis into idiopathic types and those secondary to some disease process is no longer valid. Recent studies have indicated that abnormal concentrations of force on cartilage lead to the development of this disease. A classification is presented that is based on the assumption that the process is initiated by abnormal concentrations of force on normal cartilage matrix, normal concentrations of force on abnormal cartilage matrix or normal concentrations of force on normal cartilage matrix that is supported by bone of abnormal consistency. PMID:907947

  14. Malalignment and degenerative arthropathy.

    PubMed

    Tetsworth, K; Paley, D

    1994-07-01

    The axial relationship of the joints of the lower extremity reflects both alignment and orientation. Static considerations are useful for preoperative planning and deformity correction, but dynamic considerations including compensatory gait may be more relevant clinically. Laboratory animal models have been developed that simulate the deleterious effect of malalignment on articular cartilage. Malalignment disturbs the normal transmission of force across the knee, and altered stress distribution related to deformity has been demonstrated in cadaver models using pressure-sensitive film. No prospective data are available to document the natural history of malalignment, but several retrospective studies suggest the clinical course is one of gradual progression resulting in degenerative arthropathy. The long-term follow-up of fractures is less definitive, and difficult to interpret considering the bias inherent in patient selection. Although direct clinical evidence of a cause-and-effect relationship between malalignment and arthrosis has not been possible, substantial evidence from the orthopedic literature supports this hypothesis.

  15. Stem cell-based therapeutic applications in retinal degenerative diseases

    PubMed Central

    Huang, Yiming; Enzmann, Volker; Ildstad, Suzanne T.

    2012-01-01

    Retinal degenerative diseases that target photoreceptors or the adjacent retinal pigment epithelium (RPE) affect millions of people worldwide. Retinal degeneration (RD) is found in many different forms of retinal diseases including retinitis pigmentosa (RP), age-related macular degeneration (AMD), diabetic retinopathy, cataracts, and glaucoma. Effective treatment for retinal degeneration has been widely investigated. Gene-replacement therapy has been shown to improve visual function in inherited retinal disease. However, this treatment was less effective with advanced disease. Stem cell-based therapy is being pursued as a potential alternative approach in the treatment of retinal degenerative diseases. In this review, we will focus on stem cell-based therapies in the pipeline and summarize progress in treatment of retinal degenerative disease. PMID:20859770

  16. Development of Land Segmentation, Stream-Reach Network, and Watersheds in Support of Hydrological Simulation Program-Fortran (HSPF) Modeling, Chesapeake Bay Watershed, and Adjacent Parts of Maryland, Delaware, and Virginia

    USGS Publications Warehouse

    Martucci, Sarah K.; Krstolic, Jennifer L.; Raffensperger, Jeff P.; Hopkins, Katherine J.

    2006-01-01

    The U.S. Geological Survey, U.S. Environmental Protection Agency Chesapeake Bay Program Office, Interstate Commission on the Potomac River Basin, Maryland Department of the Environment, Virginia Department of Conservation and Recreation, Virginia Department of Environmental Quality, and the University of Maryland Center for Environmental Science are collaborating on the Chesapeake Bay Regional Watershed Model, using Hydrological Simulation Program - FORTRAN to simulate streamflow and concentrations and loads of nutrients and sediment to Chesapeake Bay. The model will be used to provide information for resource managers. In order to establish a framework for model simulation, digital spatial datasets were created defining the discretization of the model region (including the Chesapeake Bay watershed, as well as the adjacent parts of Maryland, Delaware, and Virginia outside the watershed) into land segments, a stream-reach network, and associated watersheds. Land segmentation was based on county boundaries represented by a 1:100,000-scale digital dataset. Fifty of the 254 counties and incorporated cities in the model region were divided on the basis of physiography and topography, producing a total of 309 land segments. The stream-reach network for the Chesapeake Bay watershed part of the model region was based on the U.S. Geological Survey Chesapeake Bay SPARROW (SPAtially Referenced Regressions On Watershed attributes) model stream-reach network. Because that network was created only for the Chesapeake Bay watershed, the rest of the model region uses a 1:500,000-scale stream-reach network. Streams with mean annual streamflow of less than 100 cubic feet per second were excluded based on attributes from the dataset. Additional changes were made to enhance the data and to allow for inclusion of stream reaches with monitoring data that were not part of the original network. Thirty-meter-resolution Digital Elevation Model data were used to delineate watersheds for each

  17. Management of symptomatic lumbar degenerative disk disease.

    PubMed

    Madigan, Luke; Vaccaro, Alexander R; Spector, Leo R; Milam, R Alden

    2009-02-01

    Symptomatic lumbar degenerative disk disease, or discogenic back pain, is difficult to treat. Patients often report transverse low back pain that radiates into the sacroiliac joints. Radicular or claudicatory symptoms are generally absent unless there is concomitant nerve compression. Physical examination findings are often unremarkable. Radiographic examination may reveal disk space narrowing, end-plate sclerosis, or vacuum phenomenon in the disk; magnetic resonance imaging is useful for revealing hydration of the disk, annular bulging, or lumbar spine end-plate (Modic) changes in the adjacent vertebral bodies. The use of diskography as a confirmatory study remains controversial. Recent prospective, randomized trials and meta-analyses of the literature have helped expand what is known about degenerative disk disease. In most patients with low back pain, symptoms resolve without surgical intervention; physical therapy and nonsteroidal anti-inflammatory drugs are the cornerstones of nonsurgical treatment. Intradiskal electrothermal treatment has not been shown to be effective, and arthrodesis remains controversial for the treatment of discogenic back pain. Nucleus replacement and motion-sparing technology are too new to have demonstrated long-term data regarding their efficacy.

  18. Biomechanics of Artificial Disc Replacements Adjacent to a 2-Level Fusion in 4-Level Hybrid Constructs: An In Vitro Investigation

    PubMed Central

    Liao, Zhenhua; Fogel, Guy R.; Wei, Na; Gu, Hongsheng; Liu, Weiqiang

    2015-01-01

    Background The ideal procedure for multilevel cervical degenerative disc diseases remains controversial. Recent studies on hybrid surgery combining anterior cervical discectomy and fusion (ACDF) and artificial cervical disc replacement (ACDR) for 2-level and 3-level constructs have been reported in the literature. The purpose of this study was to estimate the biomechanics of 3 kinds of 4-level hybrid constructs, which are more likely to be used clinically compared to 4-level arthrodesis. Material/Methods Eighteen human cadaveric spines (C2–T1) were evaluated in different testing conditions: intact, with 3 kinds of 4-level hybrid constructs (hybrid C3–4 ACDR+C4–6 ACDF+C6–7ACDR; hybrid C3–5ACDF+C5–6ACDR+C6–7ACDR; hybrid C3–4ACDR+C4–5ACDR+C5–7ACDF); and 4-level fusion. Results Four-level fusion resulted in significant decrease in the C3–C7 ROM compared with the intact spine. The 3 different 4-level hybrid treatment groups caused only slight change at the instrumented levels compared to intact except for flexion. At the adjacent levels, 4-level fusion resulted in significant increase of contribution of both upper and lower adjacent levels. However, for the 3 hybrid constructs, significant changes of motion increase far lower than 4P at adjacent levels were only noted in partial loading conditions. No destabilizing effect or hypermobility were observed in any 4-level hybrid construct. Conclusions Four-level fusion significantly eliminated motion within the construct and increased motion at the adjacent segments. For all 3 different 4-level hybrid constructs, ACDR normalized motion of the index segment and adjacent segments with no significant hypermobility. Compared with the 4-level ACDF condition, the artificial discs in 4-level hybrid constructs had biomechanical advantages compared to fusion in normalizing adjacent level motion. PMID:26694835

  19. Hybrid surgery versus anterior cervical discectomy and fusion for multilevel cervical degenerative disc diseases: a meta-analysis

    PubMed Central

    Tian, Peng; Fu, Xin; Li, Zhi-Jun; Sun, Xiao-Lei; Ma, Xin-Long

    2015-01-01

    The objective of this meta-analysis is to compare hybrid surgery (HS) and cervical discectomy and fusion (ACDF) for multilevel cervical degenerative disc diseases (DDD). Systematic searches of all published studies through March 2015 were identified from Cochrane Library, Medline, PubMed, Embase, ScienceDirect, CNKI, WANFANG DATA and CQVIP. Randomized controlled trials (RCTs) and non-RCTs involving HS and ACDF for multilevel DDD were included. All literature was searched and assessed by two independent reviewers according to the standard of Cochrane systematic review. Data of functional and radiological outcomes in two groups were pooled, which was then analyzed by RevMan 5.2 software. One RCT and four non-RCTs encompassing 160 patients met the inclusion criteria. Meta-analysis revealed significant differences in blood loss (p = 0.005), postoperative C2–C7 ROM (p = 0.002), ROM of superior adjacent segment (p < 0.00001) and ROM of inferior adjacent segment (p = 0.0007) between the HS group and the ACDF group. No significant differences were found regarding operation time (p = 0.75), postoperative VAS (p = 0.18) and complications (p = 0.73) between the groups. Hybrid surgery demonstrated excellent clinical efficacy and radiological results. Postoperative C2–C7 ROM was closer to the physiological status. No decrease in the ROM of the adjacent segment was noted in the hybrid surgery group. PMID:26307360

  20. Degenerative disease in lumbar spine of military parachuting instructors.

    PubMed

    Bar-Dayan, Y; Weisbort, M; Bar-Dayan, Y; Velan, G J; Ravid, M; Hendel, D; Shemer, J

    2003-12-01

    Parachuting, be it static line or skydiving, places enormous stresses on the human spine. It is, therefore, important to determine the prevalence and severity of degenerative changes in the lumbar spine of subjects who practice this sport activity. Seventy four parachuting instructors, mean age 33 years and with an average of 410 static line and skydiving jumps, were included in the study. Past radiographs were examined and compared to current anterolateral and lateral views of the lumbar spine, in order to determine the prevalence of degenerative changes and document possible progression. Doubtful radiographic changes in the lumbar spine were identified in 47.4 percent of the parachuting instructors, mild degeneration in 9.6 percent, moderate degenerative disease in 10.9 percent and severe radiographic changes in 5.5 percent. Schmorll nodes were found in 8.1 percent of the subjects. Traction spurs--osteophytes were identified in 6.8 percent. The degenerative changes correlated with age and the number of jumps. Spondylolysis of L5-S1 and L3-L4 segments were observed in 12.2 and 1.4 percent respectively. Progressive spondylolisthesis was found in 2 subjects. No correlation was found between the severity of radiographic changes and either the prevalence and the severity of low back pain. The present findings provide a rational for considering repeated sheer stress as an etiology of degenerative changes in the spinal cord, and as a possible contributing factor to the pathogenesis of spondylolysis. Further study has to be done comparing parachuting instructors to a non-parachuting group, or equivalent physically active individuals, in order to assess the effect of sport-background on the development of degenerative changes.

  1. Early clinical results with cortically based pedicle screw trajectory for fusion of the degenerative lumbar spine.

    PubMed

    Glennie, R Andrew; Dea, Nicolas; Kwon, Brian K; Street, John T

    2015-06-01

    This study reviews the outcomes and revision rates of degenerative lumbar fusion surgery using cortical trajectory pedicle screws in lieu of traditional pedicle screw instrumentation. Pedicle screw fixation can be a challenge in patients with low bone mineral density. Wide posterior approaches to the lumbar spine exposing lateral to the facet joints and onto transverse processes causes an additional degree of muscular damage and blood loss not present with a simple laminectomy. A cortical bone trajectory pedicle screw has been proposed as an alternative to prevent screw pullout and decrease the morbidity associated with the wide posterior approach to the spine. We present a series of eight consecutive patients using a cortical bone trajectory instead of traditional pedicle screw fixation for degenerative conditions of the lumbar spine. A retrospective review of our institutional registry data identified eight patients who had cortical screws placed with the assistance of O-arm Stealth navigation (Medtronic Sofamor Danek, Memphis, TN, USA) from 2010-2013. We analyzed the need for revision, the maintenance of reduction and the incidence of screw pullout or breakage. Our review demonstrated that two of eight patients were revised at an average of 12months. The reasons for these revisions were pseudarthrosis and caudal adjacent segment failure. All patients who were revised had frank screw loosening. We present early clinical results of a new technique that has been shown to have a better fixation profile in laboratory testing. Our less than favorable early clinical results should be interpreted with caution and highlight important technical issues which should be considered.

  2. Degenerative myelopathy in an adult miniature poodle.

    PubMed

    Matthews, N S; de Lahunta, A

    1985-06-01

    Degenerative myelopathy was diagnosed at necropsy of an adult Miniature Poodle with a 33-month history of progressive pelvic limb ataxia and proprioceptive deficit. Microscopic examination of the cord revealed diffuse degenerative myelopathy. Degenerative myelopathy is usually seen in adult, large-breed dogs and progresses over a period of months. In this case, the myelopathy progressed slowly and the degree of paralysis became more extensive than usually seen.

  3. [Dysexecutive syndromes and degenerative diseases].

    PubMed

    Pillon, B; Czernecki, V; Dubois, B

    2004-04-01

    A dysexecutive syndrome is observed not only in frontotemporal lobar degeneration, but also in subcortical degenerative diseases, and even in Alzheimer's disease whose lesions predominate in temporoparietal associative areas. The association between a dysexecutive syndrome and various cerebral localisations may be explained by the fact that cognitive and behavioral organisation recruits anatomofunctional frontostriatal and frontoparietal circuits. Both animal experimentation and human clinical observation argue in favour of a functional continuity and complementarity among these loops. The prefrontal cortex would be particularly needed in new situations, to inhibit old programs of action not adapted to the present context and to elaborate new ones; the basal ganglia would be rather required by the repetition of the situation to progressively transform the new program in routine. If we refer to Shallice model, we can hypothesize that optimal executive functions require the preservation not only of the Supervisory Attentional System, mainly dependent on the prefrontal cortex, but also of the Contention Scheduling, recruiting the basal ganglia, and of the Schemas of Action, represented in parietal and premotor areas. Therefore, the neuropsychological assessment of patients with degenerative diseases contributes to the understanding of the anatomofunctional architecture of executive functions.

  4. Inherited Retinal Degenerative Clinical Trial Network

    DTIC Science & Technology

    2009-10-01

    ending in blindness. In the United States, the total number of individuals affected by retinitis pigmentosa (RP) and other forms of rare inherited...AD_________________ AWARD NUMBER: W81XWH-07-1-0720 TITLE: Inherited Retinal Degenerative...Final 3. DATES COVERED 27 Sep 2007 – 29 Sep 2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Inherited Retinal Degenerative Clinical Trial Network

  5. Sagittal Balance Correction in Lateral Interbody Fusion for Degenerative Scoliosis

    PubMed Central

    Gallizzi, Michael A.; Sheets, Charles; Smith, Benjamin T.; Isaacs, Robert E.; Eure, Megan; Brown, Christopher R.

    2016-01-01

    Background Sagittal balance restoration has been shown to be an important determinant of outcomes in corrective surgery for degenerative scoliosis. Lateral interbody fusion (LIF) is a less-invasive technique which permits the placement of a high lordosis interbody cage without risks associated with traditional anterior or transforaminal interbody techniques. Studies have shown improvement in lumbar lordosis following LIF, but only one other study has assessed sagittal balance in this population. The objective of this study is to evaluate the ability of LIF to restore sagittal balance in degenerative lumbar scoliosis. Methods Thirty-five patients who underwent LIF for degenerative thoracolumbar scoliosis from July 2013 to March 2014 by a single surgeon were included. Outcome measures included sagittal balance, lumbar lordosis, Cobb Angle, and segmental lordosis. Measures were evaluated pre-operative, immediately post-operatively, and at their last clinical follow-up. Repeated measures ANOVAs were used to assess the differences between pre-operative, first postoperative, and a follow-up visit. Results The average sagittal balance correction was not significantly different: 1.06cm from 5.79cm to 4.74cm forward. The average Cobb angle correction was 14.1 degrees from 21.6 to 5.5 degrees. The average change in global lumbar lordosis was found to be significantly different: 6.3 degrees from 28.9 to 35.2 degrees. Conclusions This study demonstrates that LIF reliably restores lordosis, but does not significantly improve sagittal balance. Despite this, patients had reliable improvement in pain and functionality suggesting that sagittal balance correction may not be as critical in scoliosis correction as previous studies have indicated. Clinical Relevance LIF does not significantly change sagittal balance; however, clinical improvement does not seem to be contingent upon sagittal balance correction in the degenerative scoliosis population. The DUHS IRB has determined this

  6. A case report of 3-level degenerative spondylolisthesis with spinal canal stenosis

    PubMed Central

    Moo, Ing How; Tan, See Wei; Kasat, Niraj; Thng, Leong Keng

    2014-01-01

    Introduction Lumbar degenerative spondylolisthesis is a major cause of impaired quality of life and diminished functional capacity in the elderly. Degenerative spondylolisthesis often involves only one or two level and tend to present with one or two level spinal canal stenosis. Case report The authors describe an unusual case of degenerative spondylolisthesis involving 3 levels of the lumbar spine from L2 to L5. The patient was a 58-year-old woman who suffered chronic back pain and neurogenic claudication. Plain radiography revealed grade I degenerative spondylolisthesis at L2–L3, L3–L4 and L4–L5. Elevated pedicle-facet joint angles and W-type facet joints at the lumbar spine was observed. Magnetic resonance imaging showed L2–S1 spinal cord compression at the lumbar spine. Patient underwent L2–S1 decompression laminectomy and posterior lateral fusion of L2–S1 with posterior instrumentation and bone grafting. Symptoms improved significantly at 4 months follow-up. Conclusion Thorough evaluation for multilevel segmental involvement in degenerative spondylolisthesis is important because of the frequency of severe symptomatic spinal stenosis or foraminal encroachment. Good surgical outcome can be expected from decompression and stabilisation. The pathogenesis of multi-level lumbar degenerative spondylolisthesis can be complex and heterogeneous. PMID:25666306

  7. Stereotypic behaviors in degenerative dementias.

    PubMed

    Prioni, S; Fetoni, V; Barocco, F; Redaelli, V; Falcone, C; Soliveri, P; Tagliavini, F; Scaglioni, A; Caffarra, P; Concari, L; Gardini, S; Girotti, F

    2012-11-01

    Stereotypies are simple or complex involuntary/unvoluntary behaviors, common in fronto-temporal dementia (FTD), but not studied in other types of degenerative dementias. The aim was to investigate stereotypy frequency and type in patients with FTD, Alzheimer's disease (AD), progressive supranuclear palsy (PSP) and Parkinson's disease with dementia (PDD) in a multicenter observational study; and to investigate the relation of stereotypies to cognitive, behavioral and motor impairment. One hundred fifty-five consecutive outpatients (45 AD, 40 FTD, 35 PSP and 35 PDD) were studied in four hospitals in northern Italy. Stereotypies were examined by the five-domain Stereotypy Rating Inventory. Cognition was examined by the Mini Mental State and Frontal Assessment Battery, neuropsychiatric symptoms by the Neuropsychiatric Inventory, and motor impairment and invalidity by the Unified Parkinson's Disease Rating Scale part III, and activities of daily living. Stereotypies were present in all groups. FTD and PDD had the greatest frequency of one-domain stereotypies; FTD also had the greatest frequency of two-or-more domain stereotypies; movement stereotypies were the most common stereotypies in all groups. AD patients had fewer stereotypies than the other groups. Stereotypies are not exclusive to FTD, but are also fairly common in PSP and PDD, though less so in AD. Stereotypies may be underpinned by dysfunctional striato-frontal circuits, known to be damaged in PSP and PDD, as well as FTD.

  8. Degenerative Changes of Spine in Helicopter Pilots

    PubMed Central

    Byeon, Joo Hyeon; Kim, Jung Won; Jeong, Ho Joong; Sim, Young Joo; Kim, Dong Kyu; Choi, Jong Kyoung; Im, Hyoung June

    2013-01-01

    Objective To determine the relationship between whole body vibration (WBV) induced helicopter flights and degenerative changes of the cervical and lumbar spine. Methods We examined 186 helicopter pilots who were exposed to WBV and 94 military clerical workers at a military hospital. Questionnaires and interviews were completed for 164 of the 186 pilots (response rate, 88.2%) and 88 of the 94 clerical workers (response rate, 93.6%). Radiographic examinations of the cervical and the lumbar spines were performed after obtaining informed consent in both groups. Degenerative changes of the cervical and lumbar spines were determined using four radiographs per subject, and diagnosed by two independent, blinded radiologists. Results There was no significant difference in general and work-related characteristics except for flight hours and frequency between helicopter pilots and clerical workers. Degenerative changes in the cervical spine were significantly more prevalent in the helicopter pilots compared with control group. In the cervical spine multivariate model, accumulated flight hours (per 100 hours) was associated with degenerative changes. And in the lumbar spine multivariate model, accumulated flight hours (per 100 hours) and age were associated with degenerative changes. Conclusion Accumulated flight hours were associated with degenerative changes of the cervical and lumbar spines in helicopter pilots. PMID:24236259

  9. Degenerative Joint Diseases and Neuroinflammation.

    PubMed

    Fusco, Mariella; Skaper, Stephen D; Coaccioli, Stefano; Varrassi, Giustino; Paladini, Antonella

    2016-12-31

    Rheumatic and joint diseases, as exemplified by osteoarthritis and rheumatoid arthritis, are among the most widespread painful and disabling pathologies across the globe. Given the continuing rise in life expectancy, their prevalence is destined to grow. Osteoarthritis, a degenerative joint disease, is, in particular, on its way to becoming the fourth leading cause of disability worldwide by 2020, with the rising incidence of obesity in addition to age being important factors. It is estimated that 25% of osteoarthritic individuals are unable to perform daily activities. Accompanying osteoarthritis is rheumatoid arthritis, which is a chronic systemic disease that often causes pain and deformity. At least 50% of those affected are unable to remain gainfully employed within 10 years of disease onset. A growing body of evidence now points to inflammation, locally and more systemically, as a promoter of damage to joints and bones, as well as joint-related functional deficits. The pathogenesis underlying joint diseases remains unclear; however, it is currently believed that cross-talk between cartilage and subchondral bone-and loss of balance between these two structures in joint diseases-is a critical element. This view is amplified by the presence of mast cells, whose dysregulation is associated with alterations of junction structures (cartilage, bone, synovia, matrix, nerve endings, and blood vessels). In addition, persistent activation of mast cells facilitates the development of spinal neuroinflammation mediated through their interaction with microglia. Unfortunately, current treatment strategies for rheumatic and articular disease are symptomatic and do little to limit disease progression. Research now should be directed at therapeutic modalities that target osteoarticular structural elements and thereby delaying disease progression and joint replacement.

  10. Comparison in clinical outcome of two surgical treatments in degenerative scoliosis.

    PubMed

    Sun, Yapeng; Shen, Yong; Ding, Wenyuan; Qie, Suhui; Zhang, Wei; Yang, Dalong; Wang, Linfeng

    2014-09-01

    To evaluate the clinical outcome of two different surgical treatments in treating degenerative scoliosis. Forty patients with degenerative scoliosis hospitalized in our department from June 2010 to June 2012 were selected. They were randomly divided into two groups. The first group was performed on the points with nerve or spinal compression for decompression, bone grafting, and short-segmental fixation in situ; The second group was treated with sufficient decompression, long-segmental fixation, and short-segmental fusion to operate orthopedic on scoliosis in three dimensions. All patients completed the follow-up period for more than 1 year, with the average of 18 months. Bone grafting fusion was achieved in all of the patients. The second group showed significantly better result in remission rate of postoperative pain and ODI improvement rate than the first group. Long-segmental internal fixation orthopedic is a better surgical option for patients with degenerative scoliosis to achieve sufficient decompression and three-dimensional orthopedic; therefore, it is a better solution for biomechanical reconstruction of spine.

  11. Common surgical complications in degenerative spinal surgery.

    PubMed

    Papadakis, Michael; Aggeliki, Lianou; Papadopoulos, Elias C; Girardi, Federico P

    2013-04-18

    The rapid growth of spine degenerative surgery has led to unrelenting efforts to define and prevent possible complications, the incidence of which is probably higher than that reported and varies according to the region of the spine involved (cervical and thoracolumbar) and the severity of the surgery. Several issues are becoming progressively clearer, such as complication rates in primary versus revision spinal surgery, complications in the elderly, the contribution of minimally invasive surgery to the reduction of complication rate. In this paper the most common surgical complications in degenerative spinal surgery are outlined and discussed.

  12. Development of Relations of Stream Stage to Channel Geometry and Discharge for Stream Segments Simulated with Hydrologic Simulation Program-Fortran (HSPF), Chesapeake Bay Watershed and Adjacent Parts of Virginia, Maryland, and Delaware

    USGS Publications Warehouse

    Moyer, Douglas; Bennett, Mark

    2007-01-01

    The U.S. Geological Survey (USGS), U.S. Environmental Protection Agency (USEPA), Chesapeake Bay Program (CBP), Interstate Commission for the Potomac River Basin (ICPRB), Maryland Department of the Environment (MDE), Virginia Department of Conservation and Recreation (VADCR), and University of Maryland (UMD) are collaborating to improve the resolution of the Chesapeake Bay Regional Watershed Model (CBRWM). This watershed model uses the Hydrologic Simulation Program-Fortran (HSPF) to simulate the fate and transport of nutrients and sediment throughout the Chesapeake Bay watershed and extended areas of Virginia, Maryland, and Delaware. Information from the CBRWM is used by the CBP and other watershed managers to assess the effectiveness of water-quality improvement efforts as well as guide future management activities. A critical step in the improvement of the CBRWM framework was the development of an HSPF function table (FTABLE) for each represented stream channel. The FTABLE is used to relate stage (water depth) in a particular stream channel to associated channel surface area, channel volume, and discharge (streamflow). The primary tool used to generate an FTABLE for each stream channel is the XSECT program, a computer program that requires nine input variables used to represent channel morphology. These input variables are reach length, upstream and downstream elevation, channel bottom width, channel bankfull width, channel bankfull stage, slope of the floodplain, and Manning's roughness coefficient for the channel and floodplain. For the purpose of this study, the nine input variables were grouped into three categories: channel geometry, Manning's roughness coefficient, and channel and floodplain slope. Values of channel geometry for every stream segment represented in CBRWM were obtained by first developing regional regression models that relate basin drainage area to observed values of bankfull width, bankfull depth, and bottom width at each of the 290 USGS

  13. D-penicillamine Induced Degenerative Dermopathy

    PubMed Central

    Khandpur, Sujay; Jain, Naresh; Singla, Shweta; Chatterjee, Priti; Behari, Madhuri

    2015-01-01

    D-penicillamine interferes with elastin and collagen metabolism and produces several cutaneous and multi-systemic side-effects. We present two cases of Wilson's disease who on long-term penicillamine therapy developed drug-induced degenerative dermopathy manifesting as skin fragility over pressure sites and cutis laxa-like changes. PMID:26288416

  14. Pathogenesis of degenerative temporomandibular joint arthritides.

    PubMed

    Milam, Stephen B

    2005-09-01

    Over the past decade, remarkable progress has been made in the study of molecular mechanisms involved in degenerative temporomandibular joint arthritides. Based on recent findings, models of degenerative temporomandibular joint disease predict that mechanical loads trigger a cascade of molecular events leading to disease in susceptible individuals. These events involve the production or release of free radicals, cytokines, fatty acid catabolites, neuropeptides, and matrix-degrading enzymes. Under normal circumstances, these molecules may be involved in the remodeling of articular tissues in response to changing functional demands. However, if functional demands exceed the adaptive capacity of the temporomandibular joint or if the affected individual is susceptible to maladaptive responses, then a disease state will ensue. An individual's susceptibility to degenerative temporomandibular joint disease may be determined by several factors, including genetic backdrop, sex, age, and nutritional status. It is hoped that, by furthering our understanding of the molecular events that underlie degenerative temporomandibular joint diseases, improved diagnostics and effective therapies for these debilitating conditions will be developed.

  15. Degenerative Changes in the Spine: Is This Arthritis?

    MedlinePlus

    ... doctor says I have degenerative changes in my spine. Does this mean I have arthritis? Answers from ... D. Yes. The phrase "degenerative changes" in the spine refers to osteoarthritis of the spine. Osteoarthritis is ...

  16. Electro-Optic Segment-Segment Sensors for Radio and Optical Telescopes

    NASA Technical Reports Server (NTRS)

    Abramovici, Alex

    2012-01-01

    A document discusses an electro-optic sensor that consists of a collimator, attached to one segment, and a quad diode, attached to an adjacent segment. Relative segment-segment motion causes the beam from the collimator to move across the quad diode, thus generating a measureable electric signal. This sensor type, which is relatively inexpensive, can be configured as an edge sensor, or as a remote segment-segment motion sensor.

  17. Combined transforaminal lumbar interbody fusion with posterolateral instrumented fusion for degenerative disc disease can be a safe and effective treatment for lower back pain

    PubMed Central

    Deukmedjian, Ara J; Cianciabella, Augusto J; Cutright, Jason; Deukmedjian, Arias

    2015-01-01

    Background: Lumbar fusion is a proven treatment for chronic lower back pain (LBP) in the setting of symptomatic spondylolisthesis and degenerative scoliosis; however, fusion is controversial when the primary diagnosis is degenerative disc disease (DDD). Our objective was to evaluate the safety and effectiveness of lumbar fusion in the treatment of LBP due to DDD. Materials and Methods: Two-hundred and five consecutive patients with single or multi-level DDD underwent lumbar decompression and instrumented fusion for the treatment of chronic LBP between the years of 2008 and 2011. The primary outcome measures in this study were back and leg pain visual analogue scale (VAS), patient reported % resolution of preoperative back pain and leg pain, reoperation rate, perioperative complications, blood loss and hospital length of stay (LOS). Results: The average resolution of preoperative back pain per patient was 84% (n = 205) while the average resolution of preoperative leg pain was 90% (n = 190) while a mean follow-up period of 528 days (1.5 years). Average VAS for combined back and leg pain significantly improved from a preoperative value of 9.0 to a postoperative value of 1.1 (P ≤ 0.0001), a change of 7.9 points for the cohort. The average number of lumbar disc levels fused per patient was 2.3 (range 1-4). Median postoperative LOS in the hospital was 1.2 days. Average blood loss was 108 ml perfused level. Complications occurred in 5% of patients (n = 11) and the rate of reoperation for symptomatic adjacent segment disease was 2% (n = 4). Complications included reoperation at index level for symptomatic pseudoarthrosis with hardware failure (n = 3); surgical site infection (n = 7); repair of cerebrospinal fluid leak (n = 1), and one patient death at home 3 days after discharge. Conclusion: Lumbar fusion for symptomatic DDD can be a safe and effective treatment for medically refractory LBP with or without leg pain. PMID:26692696

  18. Surgical Management of Minimally Invasive Anterior Lumbar Interbody Fusion with Stand-Alone Interbody Cage for L4-5 Degenerative Disorders: Clinical and Radiographic Findings

    PubMed Central

    Hironaka, Yasuo; Morimoto, Tetsuya; Motoyama, Yasushi; Park, Young-Su; Nakase, Hiroyuki

    2013-01-01

    Surgical treatment for degenerative spinal disorders is controversial, although lumbar fusion is considered an acceptable option for disabling lower back pain. Patients underwent instrumented minimally invasive anterior lumbar interbody fusion (mini-ALIF) using a retroperitoneal approach except for requiring multilevel fusions, severe spinal canal stenosis, high-grade spondylolisthesis, and a adjacent segments disorders. We retrospectively reviewed the clinical records and radiographs of 142 patients who received mini-ALIF for L4-5 degenerative lumbar disorders between 1998 and 2010. We compared preoperative and postoperative clinical data and radiographic measurements, including the modified Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score for back and leg pain, disc height (DH), whole lumbar lordosis (WL), and vertebral wedge angle (WA). The mean follow-up period was 76 months. The solid fusion rate was 90.1% (128/142 patients). The average length of hospital stay was 6.9 days (range, 3–21 days). The mean blood loss was 63.7 ml (range, 10–456 ml). The mean operation time was 155.5 min (range, 96–280 min). The postoperative JOA and VAS scores for back and leg pain were improved compared with the preoperative scores. Radiological analysis showed significant postoperative improvements in DH, WL, and WA, and the functional and radiographical outcomes improved significantly after 2 years. The 2.8% complication rate included cases of wound infection, liquorrhea, vertebral body fractures, and a misplaced cage that required revision. Mini-ALIF was found to be associated with improved clinical results and radiographic findings for L4-5 disorders. A retroperitoneal approach might therefore be a valuable treatment option. PMID:24140782

  19. Segmented rail linear induction motor

    DOEpatents

    Cowan, Jr., Maynard; Marder, Barry M.

    1996-01-01

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces.

  20. Segmented rail linear induction motor

    DOEpatents

    Cowan, M. Jr.; Marder, B.M.

    1996-09-03

    A segmented rail linear induction motor has a segmented rail consisting of a plurality of nonferrous electrically conductive segments aligned along a guideway. The motor further includes a carriage including at least one pair of opposed coils fastened to the carriage for moving the carriage. A power source applies an electric current to the coils to induce currents in the conductive surfaces to repel the coils from adjacent edges of the conductive surfaces. 6 figs.

  1. Vertebral degenerative disc disease severity evaluation using random forest classification

    NASA Astrophysics Data System (ADS)

    Munoz, Hector E.; Yao, Jianhua; Burns, Joseph E.; Pham, Yasuyuki; Stieger, James; Summers, Ronald M.

    2014-03-01

    Degenerative disc disease (DDD) develops in the spine as vertebral discs degenerate and osseous excrescences or outgrowths naturally form to restabilize unstable segments of the spine. These osseous excrescences, or osteophytes, may progress or stabilize in size as the spine reaches a new equilibrium point. We have previously created a CAD system that detects DDD. This paper presents a new system to determine the severity of DDD of individual vertebral levels. This will be useful to monitor the progress of developing DDD, as rapid growth may indicate that there is a greater stabilization problem that should be addressed. The existing DDD CAD system extracts the spine from CT images and segments the cortical shell of individual levels with a dual-surface model. The cortical shell is unwrapped, and is analyzed to detect the hyperdense regions of DDD. Three radiologists scored the severity of DDD of each disc space of 46 CT scans. Radiologists' scores and features generated from CAD detections were used to train a random forest classifier. The classifier then assessed the severity of DDD at each vertebral disc level. The agreement between the computer severity score and the average radiologist's score had a quadratic weighted Cohen's kappa of 0.64.

  2. Lumbar Facet Joint Motion in Patients with Degenerative Spondylolisthesis

    PubMed Central

    Yao, Qi; Wang, Shaobai; Shin, Jae-Hyuk; Li, Guoan; Wood, Kirkham B.

    2012-01-01

    Study Design Controlled laboratory study. Objective To investigate the in vivo biomechanical effect of degenerative lumbar spondylolisthesis (DLS) on the motion of the facet joint during various functional weight-bearing activities. Summary of Background Data Although the morphological changes of the facet joints in patients with DLS have been reported in a few studies, no data has been reported on the kinematics of these facet joints. Methods Ten patients with DLS at L4–L5 were studied. Each patient underwent a magnetic resonance imaging (MRI) scan to obtain three-dimensional (3D) models of the lumbar vertebrae from L2–L5 as well as a dual fluoroscopic imaging scan in different postures: flexion-extension, left-right bending and left-right torsion. The positions of the vertebrae were reproduced by matching the MRI-based vertebral models to the fluoroscopic images. The kinematics of the facet joint and the ranges of motion (ROMs) were compared with those of healthy subjects and those of patients with degenerative disc diseases (DDD) previously published. Results In DLS patients, the range of rotation of the facet joints was significantly less at the DLS level (L4–L5) than that at the adjacent levels (L2–L3 and L3–L4), while the range of translation was similar at all levels. The range of rotation at the facet joints of the DLS level decreased compared to those of both the DDD patients and healthy subjects at the corresponding vertebral level (L4–L5), while no significant difference was found in the range of translation. The ROM of facet joints in DLS and in DDD patients was similar at the adjacent levels (L2–L3 and L3–L4). Conclusion The range of rotation decreased at the facet joints at the DLS level (L4–L5) in patients compared to those in healthy subjects and DDD patients. This decrease in range of rotation implies that the DLS disease may cause restabilization of the joint. The data may help the selection of conservative treatment or different

  3. Is running associated with degenerative joint disease

    SciTech Connect

    Panush, R.S.; Schmidt, C.; Caldwell, J.R.; Edwards, N.L.; Longley, S.; Yonker, R.; Webster, E.; Nauman, J.; Stork, J.; Pettersson, H.

    1986-03-07

    Little information is available regarding the long-term effects, if any, of running on the musculoskeletal system. The authors compared the prevalence of degenerative joint disease among 17 male runners with 18 male nonrunners. Running subjects (53% marathoners) ran a mean of 44.8 km (28 miles)/wk for 12 years. Pain and swelling of hips, knees, ankles and feet and other musculoskeletal complaints among runners were comparable with those among nonrunners. Radiologic examinations (for osteophytes, cartilage thickness, and grade of degeneration) also were without notable differences among groups. They did not find an increased prevalence of osteoarthritis among the runners. Our observations suggest that long-duration, high-mileage running need to be associated with premature degenerative joint disease in the lower extremities.

  4. Physiochemical basis of human degenerative disease

    PubMed Central

    Lipinski, Boguslaw

    2015-01-01

    The onset of human degenerative diseases in humans, including type 2 diabetes, cardiovascular disease, neurological disorders, neurodevelopmental disease and neurodegenerative disease has been shown to be related to exposures to persistent organic pollutants, including polychlorinated biphenyls, chlorinated pesticides, polybrominated diphenyl ethers and others, as well as to polynuclear aromatic hydrocarbons, phthalates, bisphenol-A and other aromatic lipophilic species. The onset of these diseases has also been related to exposures to transition metal ions. A physiochemical mechanism for the onset of degenerative environmental disease dependent upon exposure to a combination of lipophilic aromatic hydrocarbons and transition metal ions is proposed here. The findings reported here also, for the first time, explain why aromatic hydrocarbons exhibit greater toxicity than aliphatic hydrocarbons of equal carbon numbers. PMID:27486355

  5. Geometry Guided Segmentation

    NASA Astrophysics Data System (ADS)

    Dunn, Stanley M.; Liang, Tajen

    1989-03-01

    Our overall goal is to develop an image understanding system for automatically interpreting dental radiographs. This paper describes the module that integrates the intrinsic image data to form the region adjacency graph that represents the image. The specific problem is to develop a robust method for segmenting the image into small regions that do not overlap anatomical boundaries. Classical algorithms for finding homogeneous regions (i.e., 2 class segmentation or connected components) will not always yield correct results since blurred edges can cause adjacent anatomical regions to be labeled as one region. This defect is a problem in this and other applications where an object count is necessary. Our solution to the problem is to guide the segmentation by intrinsic properties of the constituent objects. The module takes a set of intrinsic images as arguments. A connected components-like algorithm is performed, but the connectivity relation is not 4- or 8-neighbor connectivity in binary images; the connectivity is defined in terms of the intrinsic image data. We shall describe both the classical method and the modified segmentation procedures, and present experiments using both algorithms. Our experiments show that for the dental radiographs a segmentation using gray level data in conjunction with edges of the surfaces of teeth give a robust and reliable segmentation.

  6. Consensus Paper: Management of Degenerative Cerebellar Disorders

    PubMed Central

    Ilg, W.; Bastian, A. J.; Boesch, S.; Burciu, R. G.; Celnik, P.; Claaßen, J.; Feil, K.; Kalla, R.; Miyai, I.; Nachbauer, W.; Schöls, L.; Strupp, M.; Synofzik, M.; Teufel, J.

    2015-01-01

    Treatment of motor symptoms of degenerative cerebellar ataxia remains difficult. Yet there are recent developments that are likely to lead to significant improvements in the future. Most desirable would be a causative treatment of the underlying cerebellar disease. This is currently available only for a very small subset of cerebellar ataxias with known metabolic dysfunction. However, increasing knowledge of the pathophysiology of hereditary ataxia should lead to an increasing number of medically sensible drug trials. In this paper, data from recent drug trials in patients with recessive and dominant cerebellar ataxias will be summarized. There is consensus that up to date, no medication has been proven effective. Aminopyridines and acetazolamide are the only exception, which are beneficial in patients with episodic ataxia type 2. Aminopyridines are also effective in a subset of patients presenting with downbeat nystagmus. As such, all authors agreed that the mainstays of treatment of degenerative cerebellar ataxia are currently physiotherapy, occupational therapy, and speech therapy. For many years, well-controlled rehabilitation studies in patients with cerebellar ataxia were lacking. Data of recently published studies show that coordinative training improves motor function in both adult and juvenile patients with cerebellar degeneration. Given the well-known contribution of the cerebellum to motor learning, possible mechanisms underlying improvement will be outlined. There is consensus that evidence-based guidelines for the physiotherapy of degenerative cerebellar ataxia need to be developed. Future developments in physiotherapeutical interventions will be discussed including application of non-invasive brain stimulation. PMID:24222635

  7. Degenerative spinal disease in large felids.

    PubMed

    Kolmstetter, C; Munson, L; Ramsay, E C

    2000-03-01

    Degenerative spinal disorders, including intervertebral disc disease and spondylosis, seldom occur in domestic cats. In contrast, a retrospective study of 13 lions (Panthera leo), 16 tigers (Panthera tigris), 4 leopards (Panthera pardis), 1 snow leopard (Panthera uncia), and 3 jaguars (Panthera onca) from the Knoxville Zoo that died or were euthanatized from 1976 to 1996 indicated that degenerative spinal disease is an important problem in large nondomestic felids. The medical record, radiographic data, and the necropsy report of each animal were examined for evidence of intervertebral disc disease or spondylosis. Eight (three lions, four tigers, and one leopard) animals were diagnosed with degenerative spinal disease. Clinical signs included progressively decreased activity, moderate to severe rear limb muscle atrophy, chronic intermittent rear limb paresis, and ataxia. The age at onset of clinical signs was 10-19 yr (median = 18 yr). Radiographic evaluation of the spinal column was useful in assessing the severity of spinal lesions, and results were correlated with necropsy findings. Lesions were frequently multifocal, included intervertebral disc mineralization or herniation with collapsed intervertebral disc spaces, and were most common in the lumbar area but also involved cervical and thoracic vertebrae. Marked spondylosis was present in the cats with intervertebral disc disease, presumably subsequent to vertebral instability. Six of the animals' spinal cords were examined histologically, and five had acute or chronic damage to the spinal cord secondary to disc protrusion. Spinal disease should be suspected in geriatric large felids with decreased appetite or activity. Radiographic evaluation of the spinal column is the most useful method to assess the type and severity of spinal lesions.

  8. Developing Cellular Therapies for Retinal Degenerative Diseases

    PubMed Central

    Bharti, Kapil; Rao, Mahendra; Hull, Sara Chandros; Stroncek, David; Brooks, Brian P.; Feigal, Ellen; van Meurs, Jan C.; Huang, Christene A.; Miller, Sheldon S.

    2014-01-01

    Biomedical advances in vision research have been greatly facilitated by the clinical accessibility of the visual system, its ease of experimental manipulation, and its ability to be functionally monitored in real time with noninvasive imaging techniques at the level of single cells and with quantitative end-point measures. A recent example is the development of stem cell–based therapies for degenerative eye diseases including AMD. Two phase I clinical trials using embryonic stem cell–derived RPE are already underway and several others using both pluripotent and multipotent adult stem cells are in earlier stages of development. These clinical trials will use a variety of cell types, including embryonic or induced pluripotent stem cell–derived RPE, bone marrow– or umbilical cord–derived mesenchymal stem cells, fetal neural or retinal progenitor cells, and adult RPE stem cells–derived RPE. Although quite distinct, these approaches, share common principles, concerns and issues across the clinical development pipeline. These considerations were a central part of the discussions at a recent National Eye Institute meeting on the development of cellular therapies for retinal degenerative disease. At this meeting, emphasis was placed on the general value of identifying and sharing information in the so-called “precompetitive space.” The utility of this behavior was described in terms of how it could allow us to remove road blocks in the clinical development pipeline, and more efficiently and economically move stem cell–based therapies for retinal degenerative diseases toward the clinic. Many of the ocular stem cell approaches we discuss are also being used more broadly, for nonocular conditions and therefore the model we develop here, using the precompetitive space, should benefit the entire scientific community. PMID:24573369

  9. DEGENERATIVE STENOSIS OF THE LUMBAR SPINE

    PubMed Central

    Zylbersztejn, Sérgio; Spinelli, Leandro de Freitas; Rodrigues, Nilson Rodinei; Werlang, Pablo Mariotti; Kisaki, Yorito; Rios, Aldemar Roberto Mieres; Bello, Cesar Dall

    2015-01-01

    This paper presents an update on degenerative stenosis of the lumbar spine, which is a common pathological condition among patients over the age of 65 years. The anamnesis and physical examination need to be precise, since radiography often only provides indirect signs. Magnetic resonance imaging is necessary if the symptoms persist. The treatment for lumbar stenosis is a matter of controversy. However, there seems to be some benefit from surgical treatment rather than conservative treatment, such that surgery brings improvements in symptoms and functions for a period of up to two years. PMID:27042635

  10. The Global Deterioration Scale for assessment of primary degenerative dementia.

    PubMed

    Reisberg, B; Ferris, S H; de Leon, M J; Crook, T

    1982-09-01

    Cognitive decline associated with old age and consistent with the diagnosis of primary degenerative dementia is a unique clinical syndrome with characteristic phenomena and progression. The authors describe a Global Deterioration Scale for the assessment of primary degenerative dementia and delineation of its stages. The authors have used the Global Deterioration Scale successfully for more than 5 years and have validated it against behavioral, neuroanatomic, and neurophysiologic measures in patients with primary degenerative dementia.

  11. 1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. OVERVIEW SHOWING FIRING CONTROL BLOCKHOUSE 0502 AND ADJACENT OBSERVATION TOWER. WATER BRAKE TROUGH SEGMENT AT LOWER RIGHT. Looking north northeast. - Edwards Air Force Base, South Base Sled Track, Firing & Control Blockhouse for 10,000-foot Track, South of Sled Track at midpoint of 20,000-foot track, Lancaster, Los Angeles County, CA

  12. Transplantation of Embryonic and Induced Pluripotent Stem Cell-Derived 3D Retinal Sheets into Retinal Degenerative Mice

    PubMed Central

    Assawachananont, Juthaporn; Mandai, Michiko; Okamoto, Satoshi; Yamada, Chikako; Eiraku, Mototsugu; Yonemura, Shigenobu; Sasai, Yoshiki; Takahashi, Masayo

    2014-01-01

    Summary In this article, we show that mouse embryonic stem cell- or induced pluripotent stem cell-derived 3D retinal tissue developed a structured outer nuclear layer (ONL) with complete inner and outer segments even in an advanced retinal degeneration model (rd1) that lacked ONL. We also observed host-graft synaptic connections by immunohistochemistry. This study provides a “proof of concept” for retinal sheet transplantation therapy for advanced retinal degenerative diseases. PMID:24936453

  13. Anterior Lumbar Interbody Fusion for Degenerative Discogenic Low Back Pain

    PubMed Central

    Ni, Jianqiang; Fang, Xiutong; Zhong, Weiye; Liu, Ning; Wood, Kirkham B.

    2015-01-01

    Abstract The treatment of degenerative discogenic pain is controversial, and anterior lumbar fusion for the treatment of degenerative discogenic low back pain has also been a controversial topic for over a generation. The aim of this systematic review was to evaluate the outcome of different anterior lumbar fusion levels for degenerative discogenic low back pain. In this study, we performed a clinical outcome subgroup analysis. The outcomes of 84 consecutive patients who underwent anterior lumbar interbody fusion from 2004 to 2009 were reviewed. The operative time, intraoperative blood loss, hospital stay, Oswestry Disability Index (ODI), visual analog scale (VAS) results, and complication rate were recorded separately. Medical indications were degenerative disc disease (73.8%), postdiscectomy disc disease (16.1%), and disc herniation (9.5%). Patients with severe spondylolysis or disc degeneration, with more than 3 or multilevel lesions, were excluded. The mean operative time was 124.5 ± 10.9 min (range 51–248 min), the mean intraoperative blood loss was 242.1 ± 27.7 mL (range 50–2700 mL), the mean hospital stay was 3.9 ± 1.1 days (range 3–6 days), the mean preoperative VAS score was 7.5 ± 1.4, and the mean preoperative ODI score was 60.0 ± 5.7. At the 1-year follow-up, the mean postoperative VAS score was 3.3 ± 1.3 and the mean postoperative ODI score was 13.6 ± 3.4 (P < 0.05). L4–L5 disc fusion led to better clinical results than 2-level L4–L5/L5–S1 disc fusion. Additionally, the 2-level fusion of L4–L5/L5–S1 had better clinical results than the L5–S1 disc fusion at both the 1 and 2-year postoperative follow-ups regarding the VAS score and the ODI score. The rate of complications was more frequent in the 2-level L4–L5/L5–S1 group (27.3%) (group C) than in the L4–L5 group (9.1%) (group A) and the L5–S1 group (12.5%) (group B). There was no difference between the L4–L5 group (9.1%) and the L

  14. Degenerative disease of the lumbar spine.

    PubMed

    Kovacs, F M; Arana, E

    2016-04-01

    In the last 25 years, scientific research has brought about drastic changes in the concept of low back pain and its management. Most imaging findings, including degenerative changes, reflect anatomic peculiarities or the normal aging process and turn out to be clinically irrelevant; imaging tests have proven useful only when systemic disease is suspected or when surgery is indicated for persistent spinal cord or nerve root compression. The radiologic report should indicate the key points of nerve compression, bypassing inconsequential findings. Many treatments have proven inefficacious, and some have proven counterproductive, but they continue to be prescribed because patients want them and there are financial incentives for doing them. Following the guidelines that have proven effective for clinical management improves clinical outcomes, reduces iatrogenic complications, and decreases unjustified and wasteful healthcare expenditures.

  15. Vibration damping for the Segmented Mirror Telescope

    NASA Astrophysics Data System (ADS)

    Maly, Joseph R.; Yingling, Adam J.; Griffin, Steven F.; Agrawal, Brij N.; Cobb, Richard G.; Chambers, Trevor S.

    2012-09-01

    The Segmented Mirror Telescope (SMT) at the Naval Postgraduate School (NPS) in Monterey is a next-generation deployable telescope, featuring a 3-meter 6-segment primary mirror and advanced wavefront sensing and correction capabilities. In its stowed configuration, the SMT primary mirror segments collapse into a small volume; once on location, these segments open to the full 3-meter diameter. The segments must be very accurately aligned after deployment and the segment surfaces are actively controlled using numerous small, embedded actuators. The SMT employs a passive damping system to complement the actuators and mitigate the effects of low-frequency (<40 Hz) vibration modes of the primary mirror segments. Each of the six segments has three or more modes in this bandwidth, and resonant vibration excited by acoustics or small disturbances on the structure can result in phase mismatches between adjacent segments thereby degrading image quality. The damping system consists of two tuned mass dampers (TMDs) for each of the mirror segments. An adjustable TMD with passive magnetic damping was selected to minimize sensitivity to changes in temperature; both frequency and damping characteristics can be tuned for optimal vibration mitigation. Modal testing was performed with a laser vibrometry system to characterize the SMT segments with and without the TMDs. Objectives of this test were to determine operating deflection shapes of the mirror and to quantify segment edge displacements; relative alignment of λ/4 or better was desired. The TMDs attenuated the vibration amplitudes by 80% and reduced adjacent segment phase mismatches to acceptable levels.

  16. Adjacent-level arthroplasty following cervical fusion.

    PubMed

    Rajakumar, Deshpande V; Hari, Akshay; Krishna, Murali; Konar, Subhas; Sharma, Ankit

    2017-02-01

    OBJECTIVE Adjacent-level disc degeneration following cervical fusion has been well reported. This condition poses a major treatment dilemma when it becomes symptomatic. The potential application of cervical arthroplasty to preserve motion in the affected segment is not well documented, with few studies in the literature. The authors present their initial experience of analyzing clinical and radiological results in such patients who were treated with arthroplasty for new or persistent arm and/or neck symptoms related to neural compression due to adjacent-segment disease after anterior cervical discectomy and fusion (ACDF). METHODS During a 5-year period, 11 patients who had undergone ACDF anterior cervical discectomy and fusion (ACDF) and subsequently developed recurrent neck or arm pain related to adjacent-level cervical disc disease were treated with cervical arthroplasty at the authors' institution. A total of 15 devices were implanted (range of treated levels per patient: 1-3). Clinical evaluation was performed both before and after surgery, using a visual analog scale (VAS) for pain and the Neck Disability Index (NDI). Radiological outcomes were analyzed using pre- and postoperative flexion/extension lateral radiographs measuring Cobb angle (overall C2-7 sagittal alignment), functional spinal unit (FSU) angle, and range of motion (ROM). RESULTS There were no major perioperative complications or device-related failures. Statistically significant results, obtained in all cases, were reflected by an improvement in VAS scores for neck/arm pain and NDI scores for neck pain. Radiologically, statistically significant increases in the overall lordosis (as measured by Cobb angle) and ROM at the treated disc level were observed. Three patients were lost to follow-up within the first year after arthroplasty. In the remaining 8 cases, the duration of follow-up ranged from 1 to 3 years. None of these 8 patients required surgery for the same vertebral level during the follow

  17. Operative Management of Lumbar Degenerative Disc Disease

    PubMed Central

    Lee, Yu Chao; Osti, Orso Lorenzo

    2016-01-01

    Lumbar degenerative disc disease is extremely common. Current evidence supports surgery in carefully selected patients who have failed non-operative treatment and do not exhibit any substantial psychosocial overlay. Fusion surgery employing the correct grafting and stabilization techniques has long-term results demonstrating successful clinical outcomes. However, the best approach for fusion remains debatable. There is some evidence supporting the more complex, technically demanding and higher risk interbody fusion techniques for the younger, active patients or patients with a higher risk of non-union. Lumbar disc arthroplasty and hybrid techniques are still relatively novel procedures despite promising short-term and mid-term outcomes. Long-term studies demonstrating superiority over fusion are required before these techniques may be recommended to replace fusion as the gold standard. Novel stem cell approaches combined with tissue engineering therapies continue to be developed in expectation of improving clinical outcomes. Results with appropriate follow-up are not yet available to indicate if such techniques are safe, cost-effective and reliable in the long-term. PMID:27559465

  18. Strain gauge ambiguity sensor for segmented mirror active optical system

    NASA Technical Reports Server (NTRS)

    Wyman, C. L.; Howe, T. L. (Inventor)

    1974-01-01

    A system is described to measure alignment between interfacing edges of mirror segments positioned to form a segmented mirror surface. It serves as a gauge having a bending beam with four piezoresistive elements coupled across the interfaces of the edges of adjacent mirror segments. The bending beam has a first position corresponding to alignment of the edges of adjacent mirror segments, and it is bendable from the first position in a direction and to a degree dependent upon the relative misalignment between the edges of adjacent mirror segments to correspondingly vary the resistance of the strain guage. A source of power and an amplifier are connected in circuit with the strain gauge whereby the output of the amplifier varies according to the misalignment of the edges of adjacent mirror segments.

  19. Improvement in Recursive Hierarchical Segmentation of Data

    NASA Technical Reports Server (NTRS)

    Tilton, James C.

    2006-01-01

    A further modification has been made in the algorithm and implementing software reported in Modified Recursive Hierarchical Segmentation of Data (GSC- 14681-1), NASA Tech Briefs, Vol. 30, No. 6 (June 2006), page 51. That software performs recursive hierarchical segmentation of data having spatial characteristics (e.g., spectral-image data). The output of a prior version of the software contained artifacts, including spurious segmentation-image regions bounded by processing-window edges. The modification for suppressing the artifacts, mentioned in the cited article, was addition of a subroutine that analyzes data in the vicinities of seams to find pairs of regions that tend to lie adjacent to each other on opposite sides of the seams. Within each such pair, pixels in one region that are more similar to pixels in the other region are reassigned to the other region. The present modification provides for a parameter ranging from 0 to 1 for controlling the relative priority of merges between spatially adjacent and spatially non-adjacent regions. At 1, spatially-adjacent-/spatially- non-adjacent-region merges have equal priority. At 0, only spatially-adjacent-region merges (no spectral clustering) are allowed. Between 0 and 1, spatially-adjacent- region merges have priority over spatially- non-adjacent ones.

  20. Peritalar destabilisation syndrome (adult flatfoot with degenerative glenopathy).

    PubMed

    Pisani, Giacomo

    2010-12-01

    In cases of adult acquired flatfoot associated with peritalar destabilisation, special reference is made to the plantar calcaneo-navicular (spring) ligament's degenerative disease (degenerative glenopathy) and to the presence of the accessory navicular bone as a possible pathogenic cause. Peritalar destabilization syndrome is proposed for the articular (subtalar and talo-navicular joints) or tendinosis (tibialis posterior tendon) separately or in association with degenerative glenopathy of the coxa pedis. In degenerative glenopathy surgical reconstruction of the glenoid also makes use of a posterior tibial split to create a new tibial-navicular ligament. The concept of pronatory syndrome deemed as the root the pathological subtalar pronation, which is an entirely secondary factor in peritalar destabilisation, must be questioned. We must keep in mind that subtalar pronation and supination are respectively subsequent to opening and closing of the coxa pedis (talo-calcaneo-navicular joint) kinetic chain.

  1. Tier-Adjacency Is Not a Necessary Condition for Learning Phonotactic Dependencies

    ERIC Educational Resources Information Center

    Koo, Hahn; Callahan, Lydia

    2012-01-01

    One hypothesis raised by Newport and Aslin to explain how speakers learn dependencies between nonadjacent phonemes is that speakers track bigram probabilities between two segments that are adjacent to each other within a tier of their own. The hypothesis predicts that a dependency between segments separated from each other at the tier level cannot…

  2. End Plate Disproportion and Degenerative Disc Disease: A Case-Control Study

    PubMed Central

    Poureisa, Masoud; Daghighi, Mohammad Hossein; Mesbahi, Sepideh; Hagigi, Amir

    2014-01-01

    Study Design Case-control. Purpose To determine whether a disproportion between two neighboring vertebral end plates is associated with degenerative disc disease. Overview of Literature Recently, it has been suggested that disproportion of the end plates of two adjacent vertebrae may increase the risk of disc herniation. Methods Magnetic resonance (MR) images (n=160) with evidence of grades I-II lumbar degenerative disc disease (modified Pfirrmann's classification) and normal MR images of the lumbar region (n=160) were reviewed. On midsagittal sections, the difference of anteroposterior diameter of upper and lower end plates neighboring a degenerated (in the case group) or normal (in the control group) intervertebral disc was calculated (difference of end plates [DEP]). Results Mean DEP was significantly higher in the case group at the L5-S1 level (2.73±0.23 mm vs. 2.21±0.12 mm, p=0.03). Differences were not statistically significant at L1-L2 (1.31±0.13 mm in the cases vs. 1.28±0.08 mm in the controls, p=0.78), L2-L3 (1.45±0.12 mm in the cases vs. 1.37±0.08 mm in the controls, p=0.58), L3-L4 (1.52±0.13 mm in the cases vs. 1.49±0.10 mm in the controls, p=0.88), and L4-L5 (2.15±0.21 mm in the cases vs. 2.04±0.20 mm in the controls, p=0.31) levels. The difference at the L5-S1 level did not remain significant after adjusting for body mass index (BMI), which was significantly higher in the patients. Conclusions End plate disproportion may be a significant, BMI-dependent risk factor for lumbar degenerative disc disease. PMID:25187856

  3. Degenerative lumbar spinal stenosis and its imposters: three case studies

    PubMed Central

    Ammendolia, Carlo

    2014-01-01

    Degenerative lumbar spinal stenosis causing neurogenic claudicaton is a common condition impacting walking ability in older adults. There are other highly prevalent conditions in this patient population that have similar signs and symptoms and cause limited walking ability. The purpose of this study is to highlight the diagnostic challenges using three case studies of older adults who present with limited walking ability who have imaging evidence of degenerative lumbar spinal stenosis. PMID:25202160

  4. Minimally invasive surgery for lumbar synovial cysts with coexisting degenerative spondylolisthesis

    PubMed Central

    Hirt, Daniel; Shah, Saumya; Lu, Daniel C.; Holly, Langston T.

    2016-01-01

    Background About one third of lumbar synovial cysts are associated with degenerative spondylolisthesis. Segmental instability is thought to contribute to the pathogenesis and recurrence of synovial cysts and lumbar fusion has been advocated as a treatment of choice in the presence of spondylolisthesis. In patients with spondylolisthesis, minimally invasive resection of lumbar synovial cysts, without fusion, could minimize surgically induced segmental instability while providing good pain relief. Methods Clinical and radiological outcomes of lumbar synovial cyst patients with and without spondylolisthesis were retrospectively compared. Pain outcomes were assessed with modified Macnab criteria. Results Fifty-three patients (18 with grade 1 spondylolisthesis) underwent minimally invasive synovial cyst resection and all had either excellent or good pain outcome at ≤ 8 post- operative weeks (P = 1.000, n = 53). At > 8 post-operative weeks (mean (SD) follow-up of 200 (175) weeks), excellent or good outcomes were noted in 89% of patients without spondylolisthesis and in 75% of patients with spondylolisthesis (P = 0.425, n = 40). Four patients developed a new grade 1 spondylolisthesis at a mean follow-up of 2.6 ± 2.1 years. Nine patients were assessed for spondylolisthesis measurements at 1.2 ± 1.3 years of follow up and no significant difference was observed (5 ± 0 vs 5 ± 1 mm; P = 0.791). Two patients without spondylolisthesis and none of the patients with spondylolisthesis had a synovial cyst recurrence. Conclusion Patients with concomitant lumbar degenerative spondylolisthesis and synovial cyst can have good short- and long-term clinical outcomes with minimally invasive surgery without fusion. Post-operative segmental instability does not appear to be significant in patients with spondylolisthesis. All patients included in this article signed an informed consent for the use of their medical information for research. PMID:27909658

  5. Apparatus For Laminating Segmented Core For Electric Machine

    DOEpatents

    Lawrence, Robert Anthony; Stabel, Gerald R

    2003-06-17

    A segmented core for an electric machine includes segments stamped from coated electric steel. The segments each have a first end, a second end, and winding openings. A predetermined number of segments are placed end-to-end to form layers. The layers are stacked such that each of the layers is staggered from adjacent layers by a predetermined rotation angle. The winding openings of each of the layers are in vertical alignment with the winding openings of the adjacent layers. The stack of layers is secured to form the segmented core.

  6. EVENT SEGMENTATION

    PubMed Central

    Zacks, Jeffrey M.; Swallow, Khena M.

    2012-01-01

    One way to understand something is to break it up into parts. New research indicates that segmenting ongoing activity into meaningful events is a core component of ongoing perception, with consequences for memory and learning. Behavioral and neuroimaging data suggest that event segmentation is automatic and that people spontaneously segment activity into hierarchically organized parts and sub-parts. This segmentation depends on the bottom-up processing of sensory features such as movement, and on the top-down processing of conceptual features such as actors’ goals. How people segment activity affects what they remember later; as a result, those who identify appropriate event boundaries during perception tend to remember more and learn more proficiently. PMID:22468032

  7. Microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion for lumbar degenerative disease: short-term and medium-term outcomes

    PubMed Central

    Yang, Yang; Liu, Bin; Rong, Li-Min; Chen, Rui-Qiang; Dong, Jian-Wen; Xie, Pei-Gen; Zhang, Liang-Ming; Feng, Feng

    2015-01-01

    Objective: To evaluate short-term and medium-term outcomes of microendoscopy-assisted minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and open TLIF for lumbar degenerative disease. Methods: In this prospective, randomized control study, 50 cases received microendoscopy-assisted MIS-TLIF (MIS group), while another well-matched 50 cases accepted open TLIF (open group). Parameters between both groups, including surgical duration, intraoperative blood loss and radiologic exposure, postoperative analgesic usage and ambulatory time, visual analogue scale (VAS) for back and leg, functional scores, self-evaluation of surgical outcome (modified MacNab criteria), interbody fusion rate, adjacent segment degeneration (ASD) rate, as well as complication incidence were compared at 1 month and 24 months postoperatively. Results: Intraoperative blood loss and postoperative analgesic usage were significantly reduced in MIS group (P<0.05). Patients undergoing microendoscopy-assisted MIS-TLIF were able to ambulate earlier postoperatively than those receiving open TLIF (P<0.05). However, it showed prolonged surgical duration and enhanced radiologic exposure in MIS group (P<0.05). At 1 month postoperatively, MIS group was associated with more improvement of VAS and functional scores compared with open group (P<0.05). While at 24 months postoperatively, both groups revealed similar VAS and functional scores (P>0.05). Excellent and perfect scale rating by modified MacNab criteria, interbody fusion rate, ASD rate and complication incidence between both groups were nearly the same (P>0.05). Conclusions: Microendoscopy-assisted MIS-TLIF owns advantages of less iatrogenic injury, decreased blood loss, reduced analgesic usage and earlier rehabilitation, while it has drawbacks of more surgical duration and radiologic exposure. It is superior than open TLIF in terms of short-term clinical outcomes and has similar medium-term clinical outcomes. PMID:26885072

  8. Stand-Alone Lateral Interbody Fusion for the Treatment of Low-Grade Degenerative Spondylolisthesis

    PubMed Central

    Marchi, Luis; Abdala, Nitamar; Oliveira, Leonardo; Amaral, Rodrigo; Coutinho, Etevaldo; Pimenta, Luiz

    2012-01-01

    The purpose of this paper was to investigate the stand-alone lateral interbody fusion as a minimally invasive option for the treatment of low-grade degenerative spondylolisthesis with a minimum 24-month followup. Prospective nonrandomized observational single-center study. 52 consecutive patients (67.6 ± 10 y/o; 73.1% female; 27.4 ± 3.4 BMI) with single-level grade I/II single-level degenerative spondylolisthesis without significant spine instability were included. Fusion procedures were performed as retroperitoneal lateral transpsoas interbody fusions without screw supplementation. The procedures were performed in average 73.2 minutes and with less than 50cc blood loss. VAS and Oswestry scores showed lasting improvements in clinical outcomes (60% and 54.5% change, resp.). The vertebral slippage was reduced in 90.4% of cases from mean values of 15.1% preoperatively to 7.4% at 6-week followup (P < 0.001) and was maintained through 24 months (7.1%, P < 0.001). Segmental lordosis (P < 0.001) and disc height (P < 0.001) were improved in postop evaluations. Cage subsidence occurred in 9/52 cases (17%) and 7/52 cases (13%) spine levels needed revision surgery. At the 24-month evaluation, solid fusion was observed in 86.5% of the levels treated. The minimally invasive lateral approach has been shown to be a safe and reproducible technique to treat low-grade degenerative spondylolisthesis. PMID:22545019

  9. Kinematic Magnetic Resonance Imaging Assessment of the Degenerative Cervical Spine: Changes after Anterior Decompression and Cage Fusion.

    PubMed

    Obradov, Marina; Bénard, Menno R; Janssen, Michiel M A; Anderson, Patricia G; Heesterbeek, Petra J C; Spruit, Maarten

    2016-11-01

    Study Design A prospective cohort study. Objective Decompression and fusion of cervical vertebrae is a combined procedure that has a high success rate in relieving radicular symptoms and stabilizing or improving cervical myelopathy. However, fusion may lead to increased motion of the adjacent vertebrae and cervical deformity. Both have been postulated to lead to adjacent segment pathology (ASP). Kinematic magnetic resonance imaging (MRI) has been increasingly used to evaluate range of motion (ROM) of the cervical spine and ASP. Our objective was to measure ASP, cervical curvature, and ROM of individual segments of the cervical spine using kinematic MRI before and 24 months after monosegmental cage fusion. Methods Eighteen patients who had single-level interbody fusion were included. ROM (using kinematic MRI) and degeneration, spinal stenosis, and cervical curvature were measured preoperatively and 24 months postoperatively. Results Using kinematic MRI, segmental motion of the cervical segments was measured with a precision of less than 3 degrees. The cervical fusion did not affect the ROM of adjacent levels. However, pre- and postoperative ROM was higher at the levels immediately adjacent to the fusion level compared with those further away. In addition, at 24 months postoperatively, the number of cases with ASP was higher at the levels immediately adjacent to fusion level. Conclusions Using kinematic MRI, ROM after spinal fusion can be measured with high precision. Kinematic MRI can be used not only in clinical practice, but also to study intervention and its effect on postoperative biomechanics and ASP of cervical vertebrae.

  10. Segmented amplifier configurations for laser amplifier

    DOEpatents

    Hagen, Wilhelm F.

    1979-01-01

    An amplifier system for high power lasers, the system comprising a compact array of segments which (1) preserves high, large signal gain with improved pumping efficiency and (2) allows the total amplifier length to be shortened by as much as one order of magnitude. The system uses a three dimensional array of segments, with the plane of each segment being oriented at substantially the amplifier medium Brewster angle relative to the incident laser beam and with one or more linear arrays of flashlamps positioned between adjacent rows of amplifier segments, with the plane of the linear array of flashlamps being substantially parallel to the beam propagation direction.

  11. Connecting Malfunctioning Glial Cells and Brain Degenerative Disorders.

    PubMed

    Kaminsky, Natalie; Bihari, Ofer; Kanner, Sivan; Barzilai, Ari

    2016-06-01

    The DNA damage response (DDR) is a complex biological system activated by different types of DNA damage. Mutations in certain components of the DDR machinery can lead to genomic instability disorders that culminate in tissue degeneration, premature aging, and various types of cancers. Intriguingly, malfunctioning DDR plays a role in the etiology of late onset brain degenerative disorders such as Parkinson's, Alzheimer's, and Huntington's diseases. For many years, brain degenerative disorders were thought to result from aberrant neural death. Here we discuss the evidence that supports our novel hypothesis that brain degenerative diseases involve dysfunction of glial cells (astrocytes, microglia, and oligodendrocytes). Impairment in the functionality of glial cells results in pathological neuro-glial interactions that, in turn, generate a "hostile" environment that impairs the functionality of neuronal cells. These events can lead to systematic neural demise on a scale that appears to be proportional to the severity of the neurological deficit.

  12. Efficacy of glucosamine, chondroitin, and methylsulfonylmethane for spinal degenerative joint disease and degenerative disc disease: a systematic review

    PubMed Central

    Stuber, Kent; Sajko, Sandy; Kristmanson, Kevyn

    2011-01-01

    Background: Nutritional supplements are commonly used for a variety of musculoskeletal conditions, including knee and hip degenerative joint disease. Although these supplements are occasionally recommended for patients with degenerative disc disease and spinal degenerative joint disease, the evidence supporting this use is unknown. Objective: To systematically search and assess the quality of the literature on the use of glucosamine, chondroitin sulfate, and methylsulfonylmethane for the treatment of spinal osteoarthritis / degenerative joint disease, and degenerative disc disease. Data Sources: The Index of Chiropractic Literature, AMED, Medline, and CINAHL were searched for randomized controlled trials in English from 1984 to July 2009. Data Extraction and Synthesis: Data from studies meeting the inclusion criteria was extracted and reviewed by three reviewers. The Jadad scale was used to assess study quality. No attempts were made at meta-analysis due to variation in study design. Results: Two articles met the inclusion criteria. One study was found to have good quality but reported negative results for the supplemented group compared with placebo, the other study had low quality but reported significant positive results for the supplemented group when compared with a no intervention control group. Conclusion: There was little literature found to support the use of common nutritional supplements for spinal degeneration, making it difficult to determine whether clinicians should recommend them. PMID:21403782

  13. Factors predisposing to adjacent 2 and 3:1 disjunctions: study of 161 human reciprocal translocations.

    PubMed Central

    Jalbert, P; Sele, B

    1979-01-01

    Reciprocal translocations produce imbalances by three types of disjunction which are, in decreasing frequency, adjacent 1, 3:1, and adjacent 2. Adjacent 1 disjunction produces duplication deficiencies of inverse topography to those of adjacent 2. The imbalanced chromosome segments in one of these types are balanced in the other. The disjunction 3:1 produces pure trisomies and monosomies. The following situations predispose to adjacent 2 disjunction: translocations between the long arms of two acrocentric chromosomes or between one of these and that of a No 9 chromosome; centric segments, either short or carrying a heterochromatic zone (9qh); a balanced translocation in the mother. The factors predisposing to the disjunction adjacent 2 operate by selection, or directly on the meiotic configuration. Some of them (shortness of the interstitial segment, shortness of the short arms of translocation chromosomes) act in both these ways. Their influence is probably responsible for the repetitive and exclusive character of this disjunction. The conditions for the occurrence of the 3:1 disjunctions seem less strict than those for adjacent 2, although they should be of the same nature (involvement of acrocentrics or a chromosome 9 in the translocation, maternal origin). Images PMID:395305

  14. Posterior ventricular anchoring neochordal repair of degenerative mitral regurgitation efficiently remodels and repositions posterior leaflet prolapse†

    PubMed Central

    Woo, Y. Joseph; MacArthur, John W.

    2013-01-01

    OBJECTIVES Mitral valve repair techniques for degenerative disease typically entail leaflet resection or neochordal construction, which may require extensive resection, leaflet detachment/reattachment, reliance on diseased native chords or precise neochordal measuring. Occasionally, impaired leaflet mobility, reduced coaptation surface and systolic anterior motion (SAM) may result. We describe a novel technique for addressing posterior leaflet prolapse/flail, which both simplifies repair and addresses these issues. METHODS Fifty-four patients (age 62 ± 11 years) with degenerative MR underwent this new repair, 36 of whom minimally-invasively. A CV5 Gore-Tex suture was placed into the posterior left ventricular myocardium underneath the prolapsing segment as an anchor. This suture was then used to imbricate a portion of the prolapsed segment into the ventricle, creating a smooth, broad, non-prolapsed coapting surface on a leaflet with preserved mobility, additional neochordal support and posteriorly positioned enough to preclude SAM. RESULTS Repair was successful in all patients. The mean MR grade was reduced from +3.8 to +0.1 with 50 of 54 patients having zero MR and 4 of the 54 having trace or mild MR. All patients had proper antero-posterior location of the coaptation line of a mean length of 10.2 mm, and preserved posterior leaflet mobility. No patients had SAM or mitral stenosis. All patients were discharged and are currently doing well. CONCLUSION This new technique facilitated efficient single-suture repair of the prolapsed posterior leaflet mitral regurgitation without the need for resection or sliding annuloplasty. It precluded the need for precise neochordal measurement and preserved the leaflet coaptation surface. PMID:23449863

  15. Extreme lateral interbody fusion for the treatment of adult degenerative scoliosis.

    PubMed

    Caputo, Adam M; Michael, Keith W; Chapman, Todd M; Jennings, Jason M; Hubbard, Elizabeth W; Isaacs, Robert E; Brown, Christopher R

    2013-11-01

    Extreme lateral interbody fusion (XLIF; NuVasive Inc., San Diego, CA, USA) is a minimally invasive lateral transpsoas approach to the thoracolumbar spine. Though the procedure is rapidly increasing in popularity, limited data is available regarding its use in deformity surgery. We aimed to evaluate radiographic correction using XLIF in adults with degenerative lumbar scoliosis. Thirty consecutive patients were followed for an average of 14.3 months. Interbody fusion was completed using the XLIF technique with supplemental posterior instrumentation. Plain radiographs were obtained on all patients preoperatively, postoperatively, and at most recent follow-up. Plain radiographic measurements of coronal Cobb angle, apical vertebral translation, segmental lordosis, global lordosis, disc height, neuroforaminal height and neuroforaminal width were made at each time point. CT scans were obtained for all patients 1 year after surgery to evaluate for fusion. There was significant improvement in multiple radiographic parameters from preoperative to postoperative. Cobb angle corrected 72.3%, apical vertebral translation corrected 59.7%, neuroforaminal height increased 80.3%, neuroforaminal width increased 7.4%, and disc height increased 116.7%. Segmental lordosis at L4-L5 increased 14.1% and global lordosis increased 11.5%. There was no significant loss of correction from postoperative to most recent follow-up. There was an 11.8% pseudoarthrosis rate at levels treated with XLIF. Complications included lateral incisional hernia (n=1), rupture of anterior longitudinal ligament (n=2), wound breakdown (n=2), cardiac instability (n=1), pedicle fracture (n=1), and nonunion requiring revision (n=1). XLIF significantly improves coronal plane deformity in patients with adult degenerative scoliosis. XLIF has the ability to correct sagittal plane deformity, although it is most effective at lower lumbar levels.

  16. Segmented Coil Fails In Steps

    NASA Technical Reports Server (NTRS)

    Stedman, Ronald S.

    1990-01-01

    Electromagnetic coil degrades in steps when faults occur, continues to operate at reduced level instead of failing catastrophically. Made in segments connected in series and separated by electrically insulating barriers. Fault does not damage adjacent components or create hazard. Used to control valves in such critical applications as cooling systems of power generators and chemical process equipment, where flammable liquids or gases handled. Also adapts to electrical control of motors.

  17. Anterior Cervical Spine Surgery for Degenerative Disease: A Review

    PubMed Central

    SUGAWARA, Taku

    Anterior cervical spine surgery is an established surgical intervention for cervical degenerative disease and high success rate with excellent long-term outcomes have been reported. However, indications of surgical procedures for certain conditions are still controversial and severe complications to cause neurological dysfunction or deaths may occur. This review is focused mainly on five widely performed procedures by anterior approach for cervical degenerative disease; anterior cervical discectomy, anterior cervical discectomy and fusion, anterior cervical corpectomy and fusion, anterior cervical foraminotomy, and arthroplasty. Indications, procedures, outcomes, and complications of these surgeries are discussed. PMID:26119899

  18. The Effects of Single-Level Instrumented Lumbar Laminectomy on Adjacent Spinal Biomechanics

    PubMed Central

    Bisschop, Arno; Holewijn, Roderick M.; Kingma, Idsart; Stadhouder, Agnita; Vergroesen, Pieter-Paul A.; van der Veen, Albert J.; van Dieën, Jaap H.; van Royen, Barend J.

    2014-01-01

    Study Design Biomechanical study. Objective Posterior instrumentation is used to stabilize the spine after a lumbar laminectomy. However, the effects on the adjacent segmental stability are unknown. Therefore, we studied the range of motion (ROM) and stiffness of treated lumbar spinal segments and cranial segments after a laminectomy and after posterior instrumentation in flexion and extension (FE), lateral bending (LB), and axial rotation (AR). These outcomes might help to better understand adjacent segment disease (ASD), which is reported cranial to the level on which posterior instrumentation is applied. Methods We obtained 12 cadaveric human lumbar spines. Spines were axially loaded with 250 N for 1 hour. Thereafter, 10 consecutive load cycles (4 Nm) were applied in FE, LB, and AR. Subsequently, a laminectomy was performed either at L2 or at L4. Thereafter, load-deformation tests were repeated, after similar preloading. Finally, posterior instrumentation was added to the level treated with a laminectomy before testing was repeated. The ROM and stiffness of the treated, the cranial adjacent, and the control segments were calculated from the load-displacement data. Repeated-measures analyses of variance used the spinal level as the between-subject factor and a laminectomy or instrumentation as the within-subject factors. Results After the laminectomy, the ROM increased (+19.4%) and the stiffness decreased (−18.0%) in AR. The ROM in AR of the adjacent segments also increased (+11.0%). The ROM of treated segments after instrumentation decreased in FE (−74.3%), LB (−71.6%), and AR (−59.8%). In the adjacent segments after instrumentation, only the ROM in LB was changed (−12.9%). Conclusions The present findings do not substantiate a biomechanical pathway toward or explanation for ASD. PMID:25649753

  19. ‘Lumbar Degenerative Kyphosis’ Is Not Byword for Degenerative Sagittal Imbalance: Time to Replace a Misconception

    PubMed Central

    Lee, Chang-Hyun; Chung, Chun Kee; Jang, Jee-Soo; Kim, Sung-Min; Chin, Dong-Kyu; Lee, Jung-Kil

    2017-01-01

    Lumbar degenerative kyphosis (LDK) is a subgroup of the flat-back syndrome and is most commonly caused by unique life styles, such as a prolonged crouched posture during agricultural work and performing activities of daily living on the floor. Unfortunately, LDK has been used as a byword for degenerative sagittal imbalance, and this sometimes causes confusion. The aim of this review was to evaluate the exact territory of LDK, and to introduce another appropriate term for degenerative sagittal deformity. Unlike what its name suggests, LDK does not only include sagittal balance disorder of the lumbar spine and kyphosis, but also sagittal balance disorder of the whole spine and little lordosis of the lumbar spine. Moreover, this disease is closely related to the occupation of female farmers and an outdated Asian life style. These reasons necessitate a change in the nomenclature of this disorder to prevent misunderstanding. We suggest the name “primary degenerative sagittal imbalance” (PDSI), which encompasses degenerative sagittal misalignments of unknown origin in the whole spine in older-age patients, and is associated with back muscle wasting. LDK may be regarded as a subgroup of PDSI related to an occupation in agriculture. Conservative treatments such as exercise and physiotherapy are recommended as first-line treatments for patients with PDSI, and surgical treatment is considered only if conservative treatments failed. The measurement of spinopelvic parameters for sagittal balance is important prior to deformity corrective surgery. LDK can be considered a subtype of PDSI that is more likely to occur in female farmers, and hence the use of LDK as a global term for all degenerative sagittal imbalance disorders is better avoided. To avoid confusion, we recommend PDSI as a newer, more accurate diagnostic term instead of LDK. PMID:28264231

  20. Histopathological effects of intraoperative radiotherapy on pancreas and adjacent tissues: a postmortem analysis

    SciTech Connect

    Hoekstra, H.J.; Restrepo, C.; Kinsella, T.J.; Sindelar, W.F.

    1988-02-01

    Intraoperative radiotherapy (IORT) has been utilized in the treatment of resectable and unresectable pancreatic carcinoma at the National Cancer Institute. Detailed autopsy analyses of the radiation effects on the pancreas and adjacent tissues were performed on 13 patients dying at various times following therapy. IORT can induce a progressive retroperitoneal fibrosis and fibrosis of the porta hepatis in patients with resectable pancreatic carcinoma. In unresectable pancreatic carcinoma, the major expression of intraoperative irradiation with external beam irradiation is a progressive fibrosis of the pancreas with vascular sclerosis, nerve degeneration, atrophy of acinar cells, and atypical changes in the ducts of the pancreas, as well as degenerative changes of the pancreatic tumor.

  1. Inherited Retinal Degenerative Disease Clinical Trial Network. Addendum

    DTIC Science & Technology

    2010-10-01

    DISTRIBUTION / AVAILABILITY STATEMENT Approved for Public Release; Distribution Unlimited 13. SUPPLEMENTARY NOTES 14 . ABSTRACT 15. SUBJECT...ANSI Std. Z39.18 14 . Abstract (cont.) genotypes and phenotypes; and (iv) evaluations of the reliability and validity of different...preventive interventions for inherited orphan retinal degenerative diseases and dry age-related macular degeneration ( AMD ) through the conduct of clinical

  2. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  3. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  4. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  5. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Adjacent spaces. 148.445 Section 148.445 Shipping COAST... THAT REQUIRE SPECIAL HANDLING Additional Special Requirements § 148.445 Adjacent spaces. When... following requirements must be met: (a) Each space adjacent to a cargo hold must be ventilated by...

  6. Nonresectional Single-Suture Leaflet Remodeling for Degenerative Mitral Regurgitation Facilitates Minimally Invasive Mitral Valve Repair

    PubMed Central

    MacArthur, John W.; Cohen, Jeffrey E.; Goldstone, Andrew B.; Fairman, Alexander S.; Edwards, Bryan B.; Hornick, Matthew A.; Atluri, Pavan; Woo, Y. Joseph

    2014-01-01

    Background Both leaflet resection and neochordal construction are effective mitral repair techniques, but they may become incrementally time-consuming when using minimally invasive approaches. We have used a single-suture leaflet-remodeling technique of inverting the prolapsed or flail segment tissue into the left ventricle. This repair is straightforward, expeditious, and facilitates a minimally invasive approach. Methods Ninety-nine patients with degenerative mitral regurgitation (MR) underwent a minimally invasive single-suture repair of the mitral valve from May 2007 through December 2012. Preoperative and perioperative echocardiograms as well as patient outcomes were analyzed and compared with those obtained from patients undergoing minimally invasive mitral valve repair using quadrangular resection at the same institution during the same period. Results All 99 patients had a successful mitral repair through a sternal-sparing minimally invasive approach. Ninety-one of the 99 patients had zero MR on postoperative echocardiogram, and 8 of 99 had trace to mild MR. Patients in the nonresectional group had significantly shorter cardiopulmonary bypass and cross-clamp times compared with the quadrangular resection group (115.8 ± 41.7 minutes versus 144.9 ± 38.2 minutes; p < 0.001; 76.2 ± 28.1 minutes versus 112.6 ± 33.5 minutes; p < 0.001, respectively). The mean length of stay was 7.5 ± 3 days. All patients were discharged alive and free from clinical symptoms of MR. There have been no reoperations for recurrent MR on subsequent average follow-up of 1 year. Conclusions An effective, highly efficient, and thus far durable single-suture mitral leaflet-remodeling technique facilitates minimally invasive repair of degenerative MR. PMID:23932318

  7. Clinical outcomes of microendoscopic decompressive laminotomy for degenerative lumbar spinal stenosis.

    PubMed

    Pao, Jwo-Luen; Chen, Wein-Chin; Chen, Po-Quang

    2009-05-01

    The goal of surgical treatment for degenerative lumbar spinal stenosis (LSS) is to effectively relieve the neural structures by various decompressive techniques. Microendoscopic decompressive laminotomy (MEDL) is an attractive option because of its minimally invasive nature. The aim of prospective study was to investigate the effectiveness of MEDL by evaluating the clinical outcomes with patient-oriented scoring systems. Sixty consecutive patients receiving MEDL between December 2005 and April 2007 were enrolled. The indications of surgery were moderate to severe stenosis, persistent neurological symptoms, and failure of conservative treatment. The patients with mechanical back pain, more than grade I spondylolisthesis, or radiographic signs of instability were not included. A total of 53 patients (36 women and 17 men, mean age 62.0) were included. Forty-five patients (84.9%) were satisfied with the treatment result after a follow-up period of 15.7 months (12-24). The clinical outcomes were evaluated with the Oswestry disability index (ODI) and the Japanese Orthopedic Association (JOA) score. Of the 50 patients providing sufficient data for analysis, the ODI improved from 64.3 +/- 20.0 to 16.7 +/- 20.0. The JOA score improved from 9.4 +/- 6.1 to 24.2 +/- 6.0. The improvement rate was 73.9 +/- 30.7% and 40 patients (80%) had good or excellent results. There were 11 surgical complications: dural tear in 5, wrong level operation in 2, and transient neuralgia in 4 patients. No wound-related complication was noted. Although the prevalence of pre-operative comorbidities was very high (69.8%), there was no serious medical complication. There was no post-operative instability at the operated segment as evaluated with dynamic radiographs at final follow-up. We concluded that MEDL is a safe and very effective minimally invasive technique for degenerative LSS. With an appropriate patient selection, the risk of post-operative instability is minimal.

  8. Nanoneuromedicines for Degenerative, Inflammatory, and Infectious Nervous System Diseases

    PubMed Central

    Gendelman, Howard E.; Anantharam, Vellareddy; Bronich, Tatiana; Ghaisas, Shivani; Jin, Huajun; Kanthasamy, Anumantha G.; Liu, Xinming; McMillan, JoEllyn; Mosley, R. Lee; Narasimhan, Balaji; Mallapragada, Surya K.

    2015-01-01

    Interest in nanoneuromedicine has grown rapidly due to the immediate need for improved biomarkers and therapies for psychiatric, developmental, traumatic, inflammatory, infectious and degenerative nervous system disorders. These, in whole or in part, are a significant societal burden due to growth in numbers of affected people and in disease severity. Lost productivity of the patient and his or her caregiver, and the emotional and financial burden cannot be overstated. The need for improved health care, treatment and diagnostics are immediate. A means to such an end is nanotechnology. Indeed, recent developments of health-care enabling nanotechnologies and nanomedicines range from biomarker discovery including neuroimaging to therapeutic applications for degenerative, inflammatory and infectious disorders of the nervous system. This review focuses on the current and future potential of the field to positively affect clinical outcomes. PMID:25645958

  9. Targeting Protein Aggregation for the Treatment of Degenerative Diseases

    PubMed Central

    Eisele, Yvonne S.; Monteiro, Cecilia; Fearns, Colleen; Encalada, Sandra E.; Wiseman, R. Luke; Powers, Evan T.; Kelly, Jeffery W.

    2015-01-01

    The aggregation of specific proteins is hypothesized to underlie several degenerative diseases, collectively called amyloid disorders. However, the mechanistic connection between the process of protein aggregation and tissue degeneration is not yet fully understood. Here, we review current and emerging strategies to ameliorate aggregation-associated degenerative disorders, with a focus on disease-modifying strategies that prevent the formation of and/or eliminate protein aggregates. Persuasive pharmacologic and genetic evidence now support protein aggregation as the cause of post-mitotic tissue dysfunction or loss. However, a more detailed understanding of the factors that trigger and sustain aggregate formation, as well as the structure-activity relationships underlying proteotoxicity are needed to develop future disease-modifying therapies. PMID:26338154

  10. Immune Mechanisms in Inflammatory and Degenerative Eye Disease

    PubMed Central

    Perez, Victor L.; Caspi, Rachel R.

    2015-01-01

    It has recently been recognized that pathology of age-associated degenerative eye diseases such as adult macular degeneration (AMD), glaucoma and diabetic retinopathy, have strong immunological underpinnings. Attempts have been made to extrapolate to age-related degenerative disease insights from inflammatory processes associated with non-infectious uveitis, but these have not yet been sufficiently informative. Here we review recent findings on the immune processes underlying uveitis and those that have been shown to contribute to AMD, discussing in this context parallels and differences between overt inflammation and para-inflammation in the eye. We propose that mechanisms associated with ocular immune privilege, in combination with paucity of age-related antigen(s) within the target tissue, dampen what could otherwise be overt inflammation and result in the para-inflammation that characterizes age-associated neurodegenerative disease. PMID:25981967

  11. Segmented seal plate for a turbine engine

    SciTech Connect

    Harris, D.P.; Light, S.H.

    1990-06-12

    This patent describes a gas turbine engine. It comprises: a radial outflow, rotary compressor; a radial inflow turbine wheel; means coupling the compressor and the turbine wheel in slightly spaced, back to back relation so that the turbine wheel may drive the compressor; a housing surrounding the compressor and the turbine wheel; and a stationary seal mounted on the housing and extending into the space between the compressor and the turbine wheel, the seal including a main sealing and support section adjacent the compressor and an insulating section adjacent the turbine wheel and mounted on but generally spaced from the main support section; the insulating section comprising segments disposed in a circular array and angularly movable with respect to each other, and means sealing adjacent segments to each other.

  12. Artificial Discs for Lumbar and Cervical Degenerative Disc Disease –Update

    PubMed Central

    2006-01-01

    Executive Summary Objective To assess the safety and efficacy of artificial disc replacement (ADR) technology for degenerative disc disease (DDD). Clinical Need Degenerative disc disease is the term used to describe the deterioration of 1 or more intervertebral discs of the spine. The prevalence of DDD is roughly described in proportion to age such that 40% of people aged 40 years have DDD, increasing to 80% among those aged 80 years or older. Low back pain is a common symptom of lumbar DDD; neck and arm pain are common symptoms of cervical DDD. Nonsurgical treatments can be used to relieve pain and minimize disability associated with DDD. However, it is estimated that about 10% to 20% of people with lumbar DDD and up to 30% with cervical DDD will be unresponsive to nonsurgical treatments. In these cases, surgical treatment is considered. Spinal fusion (arthrodesis) is the process of fusing or joining 2 bones and is considered the surgical gold standard for DDD. Artificial disc replacement is the replacement of the degenerated intervertebral disc with an artificial disc in people with DDD of the lumbar or cervical spine that has been unresponsive to nonsurgical treatments for at least 6 months. Unlike spinal fusion, ADR preserves movement of the spine, which is thought to reduce or prevent the development of adjacent segment degeneration. Additionally, a bone graft is not required for ADR, and this alleviates complications, including bone graft donor site pain and pseudoarthrosis. It is estimated that about 5% of patients who require surgery for DDD will be candidates for ADR. Review Strategy The Medical Advisory Secretariat conducted a computerized search of the literature published between 2003 and September 2005 to answer the following questions: What is the effectiveness of ADR in people with DDD of the lumbar or cervical regions of the spine compared with spinal fusion surgery? Does an artificial disc reduce the incidence of adjacent segment degeneration (ASD

  13. Decompression without Fusion for Low-Grade Degenerative Spondylolisthesis

    PubMed Central

    Cheung, Jason Pui Yin; Cheung, Prudence Wing Hang; Cheung, Kenneth Man Chee

    2016-01-01

    Study Design Retrospective series. Purpose Assess results of decompression-only surgery for low-grade degenerative spondylolisthesis with consideration of instability. Overview of Literature There is no consensus on whether fusion or decompression-only surgery leads to better outcomes for patients with low-grade degenerative spondylolisthesis. Current trends support fusion but many studies are flawed due to over-generalization without consideration of radiological instability and their variable presentations and natural history. Methods Patients with surgically treated degenerative spondylolisthesis from 1990–2013 were included. Clinical and radiological instability measures were included. Any residual or recurrence of symptoms, revision surgery performed and functional outcome scores including the numerical global rate of change scale, visual analogue scale, and modified Barthel index were measured. Follow-up periods for patients were divided into short-term (<5 years), mid-term (5–10 years) and long-term (>10 years). Results A total of 64 patients were recruited. Mechanical low back pain was noted in 48 patients and most (85.4%) had relief of back pain postoperatively. Radiological instability was noted in 4 subjects by flexion-extension radiographs and 12 subjects with prone traction radiographs by increased disc height and reduction of olisthesis and slip angle. From the results of the short-term, mid-term and long-term follow-up, reoperation only occurred within the first 5-year follow-up period. All functional scores improved from preoperative to postoperative 1-year follow-up. Conclusions Decompression-only for low-grade degenerative spondylolisthesis has good long-term results despite instability. Further higher-level studies should be performed on this patient group with radiological instability to suggest the superior surgical option. PMID:26949462

  14. Is epidural steroid injection effective for degenerative lumbar spinal stenosis?

    PubMed

    Flores, Sebastián; Molina, Marcelo

    2015-11-16

    There are several nonsurgical alternatives to treat radicular pain in degenerative lumbar spinal stenosis. Epidural steroid injections have been used for several decades, but the different studies have shown variable effects. Searching in Epistemonikos database, which is maintained by screening 30 databases, we identified nine systematic reviews including seven pertinent randomized controlled trials. We concluded epidural steroid injection probably leads to little or no effect on reducing radicular pain of spinal stenosis.

  15. Degenerative disorders of the temporomandibular joint: etiology, diagnosis, and treatment.

    PubMed

    Tanaka, E; Detamore, M S; Mercuri, L G

    2008-04-01

    Temporomandibular joint (TMJ) disorders have complex and sometimes controversial etiologies. Also, under similar circumstances, one person's TMJ may appear to deteriorate, while another's does not. However, once degenerative changes start in the TMJ, this pathology can be crippling, leading to a variety of morphological and functional deformities. Primarily, TMJ disorders have a non-inflammatory origin. The pathological process is characterized by deterioration and abrasion of articular cartilage and local thickening. These changes are accompanied by the superimposition of secondary inflammatory changes. Therefore, appreciating the pathophysiology of the TMJ degenerative disorders is important to an understanding of the etiology, diagnosis, and treatment of internal derangement and osteoarthrosis of the TMJ. The degenerative changes in the TMJ are believed to result from dysfunctional remodeling, due to a decreased host-adaptive capacity of the articulating surfaces and/or functional overloading of the joint that exceeds the normal adaptive capacity. This paper reviews etiologies that involve biomechanical and biochemical factors associated with functional overloading of the joint and the clinical, radiographic, and biochemical findings important in the diagnosis of TMJ-osteoarthrosis. In addition, non-invasive and invasive modalities utilized in TMJ-osteoarthrosis management, and the possibility of tissue engineering, are discussed.

  16. Potential of Bone Marrow Stromal Cells in Applications for Neuro-Degenerative, Neuro-Traumatic and Muscle Degenerative Diseases

    PubMed Central

    Dezawa, Mari; Ishikawa, Hiroto; Hoshino, Mikio; Itokazu, Yutaka; Nabeshima, Yo-ichi

    2005-01-01

    Cell transplantation is a promising strategy for the treatment of neurodegenerative and muscle degenerative diseases. Many kinds of cells, including embryonic stem cells and tissue stem cells, have been considered as candidates for transplantation therapy. Bone marrow stromal cells (MSCs) have great potential as therapeutic agents since they are easy to isolate and can be expanded from patients without serious ethical or technical problems. We discovered a new method for the highly efficient and specific induction of functional Schwann cells, neurons and skeletal muscle lineage cells from both rat and human MSCs. These induced cells were transplanted into animal models of neurotraumatic injuries, Parkinson’s disease, stroke and muscle dystrophies, resulting in the successful integration of transplanted cells and an improvement in behavior of the transplanted animals. Here we focus on the respective potentials of MSC-derived cells and discuss the possibility of clinical application in degenerative diseases. PMID:18369401

  17. [Degenerative espondylolisthesis. Body mass index influence on the post-surgical evolution].

    PubMed

    Vázquez-Aguilar, A; Torres-Gómez, A; Atlitec-Castillo, P T; De León-Martínez, J E

    2016-01-01

    Spondylolisthesis is the sliding of a vertebral body with respect to the adjacent one. According to the degree of slippage it is classified into 4 Meyerding grades. Patients with spondylolisthesis who underwent surgery with lumbar instrumentation were included. They were divided into two groups based on their body mass index: obese and non-obese. The functional capacity Oswestry score was calculated preoperatively and at one year, and it was correlated with the BMI. A total of 46 patients, 26 females and 20 males, were included, from 2010 to 2013, all of them with a diagnosis of degenerative spondylolisthesis with lumbar stenosis. Mean age was 58.9 years. The mean preoperative Oswestry disability index was 41% in non-obese patients and 47% in obese patients. At the one-year postoperative assessment the disability index was 12.30% in non-obese patients and 23.84% in obese patients. Non-obese patients had a more favorable clinical course compared to the group of obese patients.

  18. Motion-preserving technologies for degenerative lumbar spine: The past, present, and future horizons

    PubMed Central

    Serhan, Hassan; Mhatre, Devdatt; Defossez, Henri; Bono, Christopher M.

    2011-01-01

    Over the past few decades, remarkable advancements in the understanding of the origin of low-back pain and lumbar spinal disorders have been achieved. Spinal fusion is generally considered the “gold standard” in the treatment of low-back pain; however, fusion is also associated with accelerated degeneration of adjacent levels. Spinal arthroplasty and dynamic stabilization technologies, as well as the continuous improvement in diagnosis and surgical interventions, have opened a new era of treatment options. Recent advancements in nonfusion technologies such as motion-preservation devices and posterior dynamic stabilization may change the gold standard. These devices are designed with the intent to provide stabilization and eliminate pain while preserving motion of the functional spinal unit. The adaption of nonfusion technologies by the surgical community and payers for the treatment of degenerative spinal conditions will depend on the long-term clinical outcome of controlled randomized clinical studies. Although the development of nonfusion technology has just started and the adoption is very slow, it may be considered a viable option for motion preservation in coming years. This review article provides technical and surgical views from the past and from the present, as well as a glance at the future endeavors and challenges in instrumentation development for lumbar spinal disorders. © 2011 SAS - The International Society for the Advancement of Spine Surgery. Published by Elsevier Inc. All rights reserved. PMID:25802672

  19. Posterior lumbar interbody fusion with cortical bone trajectory screw fixation versus posterior lumbar interbody fusion using traditional pedicle screw fixation for degenerative lumbar spondylolisthesis: a comparative study.

    PubMed

    Sakaura, Hironobu; Miwa, Toshitada; Yamashita, Tomoya; Kuroda, Yusuke; Ohwada, Tetsuo

    2016-11-01

    OBJECTIVE Several biomechanical studies have demonstrated the favorable mechanical properties of the cortical bone trajectory (CBT) screw. However, no reports have examined surgical outcomes of posterior lumbar interbody fusion (PLIF) with CBT screw fixation for degenerative spondylolisthesis (DS) compared with those after PLIF using traditional pedicle screw (PS) fixation. The purposes of this study were thus to elucidate surgical outcomes after PLIF with CBT screw fixation for DS and to compare these results with those after PLIF using traditional PS fixation. METHODS Ninety-five consecutive patients underwent PLIF with CBT screw fixation for DS (CBT group; mean followup 35 months). A historical control group consisted of 82 consecutive patients who underwent PLIF with traditional PS fixation (PS group; mean follow-up 40 months). Clinical status was assessed using the Japanese Orthopaedic Association (JOA) scale score. Fusion status was assessed by dynamic plain radiographs and CT. The need for additional surgery and surgery-related complications was also evaluated. RESULTS The mean JOA score improved significantly from 13.7 points before surgery to 23.3 points at the latest follow-up in the CBT group (mean recovery rate 64.4%), compared with 14.4 points preoperatively to 22.7 points at final follow-up in the PS group (mean recovery rate 55.8%; p < 0.05). Solid spinal fusion was achieved in 84 patients from the CBT group (88.4%) and in 79 patients from the PS group (96.3%, p > 0.05). Symptomatic adjacent-segment disease developed in 3 patients from the CBT group (3.2%) compared with 9 patients from the PS group (11.0%, p < 0.05). CONCLUSIONS PLIF with CBT screw fixation for DS provided comparable improvement of clinical symptoms with PLIF using traditional PS fixation. However, the successful fusion rate tended to be lower in the CBT group than in the PS group, although the difference was not statistically significant between the 2 groups.

  20. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 43 Public Lands: Interior 1 2014-10-01 2014-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  1. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 43 Public Lands: Interior 1 2012-10-01 2011-10-01 true Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  2. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 43 Public Lands: Interior 1 2013-10-01 2013-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  3. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 43 Public Lands: Interior 1 2010-10-01 2010-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  4. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Adjacent lands. 420.3 Section 420.3 Public Lands: Interior Regulations Relating to Public Lands BUREAU OF RECLAMATION, DEPARTMENT OF THE INTERIOR OFF-ROAD VEHICLE USE § 420.3 Adjacent lands. When administratively feasible, the regulation of...

  5. Degenerative spondylolisthesis: contemporary review of the role of interbody fusion.

    PubMed

    Baker, Joseph F; Errico, Thomas J; Kim, Yong; Razi, Afshin

    2017-02-01

    Degenerative spondylolisthesis is a common presentation, yet the best surgical treatment continues to be a matter of debate. Interbody fusion is one of a number of options, but its exact role remains ill defined. The aim of this study was to provide a contemporary review of the literature to help determine the role, if any, of interbody fusion in the surgical treatment of degenerative spondylolisthesis. A systematic review of the literature since 2005 was performed. Details on study size, patient age, surgical treatments, levels of slip, patient reported outcome measures, radiographic outcomes, complications and selected utility measures were recorded. Studies that compared a cohort treated with interbody fusion and at least one other surgical intervention for comparison were included for review. Only studies examining the effect in degenerative spondylolisthesis were included. Two authors independently reviewed the manuscripts and extracted key data. Thirteen studies were included in the final analysis. A total of 565 underwent interbody fusion and 761 underwent other procedures including decompression alone, interspinous stabilisation and posterolateral fusion with or without instrumentation. Most studies were graded Level III evidence. Heterogeneous reporting of outcomes prevented formal statistical analysis. However, in general, studies reviewed concluded no significant clinical or radiographic difference in outcome between interbody fusion and other treatments. Two small studies suggested interbody fusion is a better option in cases of definite instability. Interbody fusion only provided outcomes as good as instrumented posterolateral fusion. However, most studies were Level III, and hence, we remain limited in defining the exact role of interbody fusion-cases with clear instability appear to be most appropriate. Future work should use agreed-upon common outcome measures and definitions.

  6. Serial Case Reporting Yoga for Idiopathic and Degenerative Scoliosis

    PubMed Central

    Groessl, Erik J.; Sherman, Karen J.

    2014-01-01

    Background: Non-surgical techniques for treating scoliosis frequently focus on realigning the spine, typically by muscular relaxation or muscular or ligamentous stretching. However, such treatments, which include physical therapeutic, chiropractic, and bracing techniques, are inconsistently supported by current evidence. In this study, we assess the possible benefits of asymmetrical strengthening of truncal muscles on the convex side of the scoliotic curve through a single yoga pose, the side plank pose, in idiopathic and degenerative scoliosis. Methods: Twenty-five patients with idiopathic or degenerative scoliosis and primary curves measuring 6 to 120 degrees by the Cobb method had spinal radiographs and were then taught the side plank pose. After 1 week performing the pose with convexity downward for 10 to 20 seconds, they were instructed to maintain the posture once daily for as long as possible on that one side only. A second series of spinal radiographs was taken 3 to 22 months later. Pre- and post-yoga Cobb measurements were compared. Results: The mean self-reported practice of the yoga pose was 1.5 minutes per day, 6.1 days per week, for a mean follow-up period of 6.8 months. Among all patients, a significant improvement in the Cobb angle of the primary scoliotic curve of 32.0% was found. Among 19 compliant patients, the mean improvement rose to 40.9%. Improvements did not differ significantly among adolescent idiopathic and degenerative subtypes (49.6% and 38.4%, respectively). Conclusions: Asymmetrically strengthening the convex side of the primary curve with daily practice of the side plank pose held for as long as possible for an average of 6.8 months significantly reduced the angle of primary scoliotic curves. These results warrant further testing. PMID:25568820

  7. Degenerative lumbar spinal stenosis and lumbar spine configuration

    PubMed Central

    Hamoud, K.; May, H.; Hay, O.; Medlej, B.; Masharawi, Y.; Peled, N.; Hershkovitz, I.

    2010-01-01

    As life expectancy increases, degenerative lumbar spinal stenosis (DLSS) becomes a common health problem among the elderly. DLSS is usually caused by degenerative changes in bony and/or soft tissue elements. The poor correlation between radiological manifestations and the clinical picture emphasizes the fact that more studies are required to determine the natural course of this syndrome. Our aim was to reveal the association between lower lumbar spine configuration and DLSS. Two groups were studied: the first included 67 individuals with DLSS (mean age 66 ± 10) and the second 100 individuals (mean age 63.4 ± 13) without DLSS-related symptoms. Both groups underwent CT images (Philips Brilliance 64) and the following measurements were performed: a cross-section area of the dural sac, vertebral body dimensions (height, length and width), AP diameter of the bony spinal canal, lumbar lordosis and sacral slope angles. All measurements were taken at L3 to S1. Vertebral body lengths were significantly greater in the DLSS group at all levels compared to the control, whereas anterior vertebral body heights (L3, L4, L5) and middle vertebral heights (L3, L5) were significantly smaller in the LSS group. Lumbar lordosis, sacral slope and bony spinal canal were significantly smaller in the DLSS compared to the control. We conclude that the size and shape of vertebral bodies and canals significantly differed between the study groups. A tentative model is suggested to explain the association between these characteristics and the development of degenerative spinal stenosis. PMID:20652366

  8. Unsupervised Segmentation Of Texture Images

    NASA Astrophysics Data System (ADS)

    Michel, Xavier; Leonardi, Riccardo; Gersho, Allen

    1988-10-01

    Past work on unsupervised segmentation of a texture image has been based on several restrictive assumptions to reduce the difficulty of this challenging segmentation task. Typically, a fixed number of different texture regions is assumed and each region is assumed to be generated by a simple model. Also, different first order statistics are used to facilitate discrimination between different textures. This paper introduces an approach to unsupervised segmentation that offers promise for handling unrestricted natural scenes containing textural regions. A simple but effective feature set and a novel measure of dissimilarity are used to accurately generate boundaries between an unknown number of regions without using first order statistics or texture models. A two stage approach is used to partition a texture image. In the first stage, a set of sliding windows scans the image to generate a sequence of feature vectors. The windowed regions providing the highest inhomo-geneity in their textural characteristics determine a crude first-stage boundary, separating textured areas that are unambiguously homogeneous from one another. These regions are used to estimate a set of prototype feature vectors. In the second stage, supervised segmentation is performed to obtain an accurate boundary between different textured regions by means of a constrained hierarchical clustering technique. Each inhomo-geneous window obtained in the first stage is split into four identical subwindows for which the feature vectors are estimated. Each of the subwindows is assigned to a homogeneous region to which it is connected. This region is chosen according to the closest prototype vector in the feature space. Any two adjacent subwindows that are assigned to different regions will in turn be considered as inhomogeneous windows and each is then split into four subwindows. The classification scheme is repeated in this hierarchical manner until the desired boundary resolution is achieved. The

  9. Revisiting the Term Neuroprotection in Chronic and Degenerative Diseases

    PubMed Central

    Orsini, Marco; Nascimento, Osvaldo J.M.; Matta, Andre P.C.; Reis, Carlos Henrique Melo; de Souza, Olivia Gameiro; Bastos, Victor Hugo; Moreira, Rayele; Ribeiro, Pedro; Fiorelli, Stenio; Novellino, Pietro; Pessoa, Bruno; Cunha, Mariana; Pupe, Camila; Morales, Pedro S.; Filho, Pedro F. Moreira; Trajano, Eduardo Lima; Oliveira, Acary Bulle

    2016-01-01

    Thanks to the development of several new researches, the lifetime presented a significant increase, even so, we still have many obstacles to overcome – among them, manage and get responses regarding neurodegenerative diseases. Where we are in the understanding of neuroprotection? Do we really have protective therapies for diseases considered degeneratives such as amyotrophic lateral sclerosis and its variants, Parkinson’s disease, Alzheimer’s disease and many others? Neuroprotection is defined by many researches as interactions and interventions that can slow down or even inhibit the progression of neuronal degeneration process. We make some considerations on this neuroprotective effect. PMID:27127599

  10. MicroRNA Expression Signature in Degenerative Aortic Stenosis

    PubMed Central

    2016-01-01

    Degenerative aortic stenosis, characterized by narrowing of the exit of the left ventricle of the heart, has become the most common valvular heart disease in the elderly. The aim of this study was to investigate the microRNA (miRNA) signature in degenerative AS. Through microarray analysis, we identified the miRNA expression signature in the tissue samples from healthy individuals (n = 4) and patients with degenerative AS (n = 4). Six miRNAs (hsa-miR-193a-3p, hsa-miR-29b-1-5p, hsa-miR-505-5p, hsa-miR-194-5p, hsa-miR-99b-3p, and hsa-miR-200b-3p) were overexpressed and 14 (hsa-miR-3663-3p, hsa-miR-513a-5p, hsa-miR-146b-5p, hsa-miR-1972, hsa-miR-718, hsa-miR-3138, hsa-miR-21-5p, hsa-miR-630, hsa-miR-575, hsa-miR-301a-3p, hsa-miR-636, hsa-miR-34a-3p, hsa-miR-21-3p, and hsa-miR-516a-5p) were downregulated in aortic tissue from AS patients. GeneSpring 13.1 was used to identify potential human miRNA target genes by comparing a 3-way comparison of predictions from TargetScan, PITA, and microRNAorg databases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to identify potential pathways and functional annotations associated with AS. Twenty miRNAs were significantly differentially expressed between patients with AS samples and normal controls and identified potential miRNA targets and molecular pathways associated with this morbidity. This study describes the miRNA expression signature in degenerative AS and provides an improved understanding of the molecular pathobiology of this disease. PMID:27579316

  11. MicroRNA Expression Signature in Degenerative Aortic Stenosis.

    PubMed

    Shi, Jing; Liu, Hui; Wang, Hui; Kong, Xiangqing

    2016-01-01

    Degenerative aortic stenosis, characterized by narrowing of the exit of the left ventricle of the heart, has become the most common valvular heart disease in the elderly. The aim of this study was to investigate the microRNA (miRNA) signature in degenerative AS. Through microarray analysis, we identified the miRNA expression signature in the tissue samples from healthy individuals (n = 4) and patients with degenerative AS (n = 4). Six miRNAs (hsa-miR-193a-3p, hsa-miR-29b-1-5p, hsa-miR-505-5p, hsa-miR-194-5p, hsa-miR-99b-3p, and hsa-miR-200b-3p) were overexpressed and 14 (hsa-miR-3663-3p, hsa-miR-513a-5p, hsa-miR-146b-5p, hsa-miR-1972, hsa-miR-718, hsa-miR-3138, hsa-miR-21-5p, hsa-miR-630, hsa-miR-575, hsa-miR-301a-3p, hsa-miR-636, hsa-miR-34a-3p, hsa-miR-21-3p, and hsa-miR-516a-5p) were downregulated in aortic tissue from AS patients. GeneSpring 13.1 was used to identify potential human miRNA target genes by comparing a 3-way comparison of predictions from TargetScan, PITA, and microRNAorg databases. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were performed to identify potential pathways and functional annotations associated with AS. Twenty miRNAs were significantly differentially expressed between patients with AS samples and normal controls and identified potential miRNA targets and molecular pathways associated with this morbidity. This study describes the miRNA expression signature in degenerative AS and provides an improved understanding of the molecular pathobiology of this disease.

  12. Plantar fasciitis: a degenerative process (fasciosis) without inflammation.

    PubMed

    Lemont, Harvey; Ammirati, Krista M; Usen, Nsima

    2003-01-01

    The authors review histologic findings from 50 cases of heel spur surgery for chronic plantar fasciitis. Findings include myxoid degeneration with fragmentation and degeneration of the plantar fascia and bone marrow vascular ectasia. Histologic findings are presented to support the thesis that "plantar fasciitis" is a degenerative fasciosis without inflammation, not a fasciitis. These findings suggest that treatment regimens such as serial corticosteroid injections into the plantar fascia should be reevaluated in the absence of inflammation and in light of their potential to induce plantar fascial rupture.

  13. Health assessment of environmental pollutants; Proliferative and degenerative diseases

    SciTech Connect

    Stuart, B.O. )

    1987-01-01

    The health assessments of environmental air contaminants are at present frequently based upon probability of cancer, if this has been identified as a potential result of prolonged exposure to the particular inhalation hazard. However, for many airborne hazards chronic inhalation exposure may result in morbidity or mortality risks due to chronic degenerative diseases such as emphysema, fibrosis, or chronic obstructive pulmonary disease that may be nearly as great or greater than those of more widely recognized neoplastic or proliferative disease. The relative hazards of environmentally released radioactive and chemical air contaminants, i.e., radon daughters and diesel engine exhaust, are discussed as examples.

  14. A comprehensive segmentation analysis of crude oil market based on time irreversibility

    NASA Astrophysics Data System (ADS)

    Xia, Jianan; Shang, Pengjian; Lu, Dan; Yin, Yi

    2016-05-01

    In this paper, we perform a comprehensive entropic segmentation analysis of crude oil future prices from 1983 to 2014 which used the Jensen-Shannon divergence as the statistical distance between segments, and analyze the results from original series S and series begin at 1986 (marked as S∗) to find common segments which have same boundaries. Then we apply time irreversibility analysis of each segment to divide all segments into two groups according to their asymmetry degree. Based on the temporal distribution of the common segments and high asymmetry segments, we figure out that these two types of segments appear alternately and do not overlap basically in daily group, while the common portions are also high asymmetry segments in weekly group. In addition, the temporal distribution of the common segments is fairly close to the time of crises, wars or other events, because the hit from severe events to oil price makes these common segments quite different from their adjacent segments. The common segments can be confirmed in daily group series, or weekly group series due to the large divergence between common segments and their neighbors. While the identification of high asymmetry segments is helpful to know the segments which are not affected badly by the events and can recover to steady states automatically. Finally, we rearrange the segments by merging the connected common segments or high asymmetry segments into a segment, and conjoin the connected segments which are neither common nor high asymmetric.

  15. Segmental mediolytic arteritis: a clinical pathologic study.

    PubMed

    Slavin, R E; Gonzalez-Vitale, J C

    1976-07-01

    A distinct arterial lesion was observed in the large abdominal muscular arteries in three autopsied patients. The salient histopathologic feature of this arterial lesion was either partial or total mediolysis. This was accompanied by a linear fibrin deposit between the media and adventitia and a variable nonpleomorphic inflammatory infiltrate. Total mediolysis led to the formation of arterial gaps. Disecting aneurysms frequently occurred and began either adjacent to arterial gaps or as a result of capillary hemorrhages in areas of partial mediolysis. Ruptured aneurysms led to massive intraabdominal hemorrhages. Arterial luminal occlusion, either by thrombi or dissection, resulted in ischemic bowel changes and renal infarcts. In addition, the arteries affected by mediolysis also showed medial degenerative changes, akin to cystic medial necrosis. Concomitant changes in the kidney showed mesangial hyperplasia; the heart exhibited histiocytic infiltrates and rare Aschoff-like bodies and capsular inflammation were seen in the spleen. The pathogenesis of the arterial lesions is unknown. A possible explanation is that this arteritis may have been induced by immune complexes and that local arterial medial degenerative changes predispose the involved arteries to immunologic injury.

  16. Prosodic cues enhance rule learning by changing speech segmentation mechanisms

    PubMed Central

    de Diego-Balaguer, Ruth; Rodríguez-Fornells, Antoni; Bachoud-Lévi, Anne-Catherine

    2015-01-01

    Prosody has been claimed to have a critical role in the acquisition of grammatical information from speech. The exact mechanisms by which prosodic cues enhance learning are fully unknown. Rules from language often require the extraction of non-adjacent dependencies (e.g., he plays, he sings, he speaks). It has been proposed that pauses enhance learning because they allow computing non-adjacent relations helping word segmentation by removing the need to compute adjacent computations. So far only indirect evidence from behavioral and electrophysiological measures comparing learning effects after exposure to speech with and without pauses support this claim. By recording event-related potentials during the acquisition process of artificial languages with and without pauses between words with embedded non-adjacent rules we provide direct evidence on how the presence of pauses modifies the way speech is processed during learning to enhance segmentation and rule generalization. The electrophysiological results indicate that pauses as short as 25 ms attenuated the N1 component irrespective of whether learning was possible or not. In addition, a P2 enhancement was present only when learning of non-adjacent dependencies was possible. The overall results support the claim that the simple presence of subtle pauses changed the segmentation mechanism used reflected in an exogenously driven N1 component attenuation and improving segmentation at the behavioral level. This effect can be dissociated from the endogenous P2 enhancement that is observed irrespective of the presence of pauses whenever non-adjacent dependencies are learned. PMID:26483731

  17. Static and Dynamic Parameters in Patients With Degenerative Flat Back and Change After Corrective Fusion Surgery

    PubMed Central

    2016-01-01

    Objective To evaluate characteristics of static and dynamic parameters in patients with degenerative flat back (DFB) and to compare degree of their improvement between successful and unsuccessful surgical outcome groups Methods Forty-seven patients with DFB were included who took whole spine X-ray and three-dimensional motion analysis before and 6 months after corrective surgery. Forty-four subjects were selected as a control group. As static parameters, thoracic kyphosis (TK), thoracolumbar junction (TLJ), lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), and pelvic tilt (PT) were measured. As dynamic parameters, maximal and minimal angle of pelvic tilt, lower limb joints, and thoracic and lumbar vertebrae column (dynamic TK and LL) in sagittal plane were obtained. Results The DFB group showed smaller TK and larger LL, pelvic posterior tilt, hip flexion, knee flexion, and ankle dorsiflexion than the control group. Most of these parameters were significantly corrected by fusion surgery. Dynamic spinal parameters correlated with static spinal parameters. The successful group obtained significant improvement in maximal and minimal dynamic LL than the unsuccessful group. Conclusion The DFB group showed characteristic lower limb and spinal angles in dynamic and static parameters. Correlation between static and dynamic parameters was found in spinal segment. Dynamic LL was good predictor of successful surgical outcomes. PMID:27606275

  18. Does lumbar paraspinal muscles improve after corrective fusion surgery in degenerative flat black?

    PubMed Central

    Lee, Jung Hwan; Lee, Sang-Ho

    2017-01-01

    Background: Degenerative flat back (DFB) is characterized by sagittal imbalance resulting from the loss of lumbar lordosis (LL). Extensive degeneration and weakness of lumbar paraspinal extensor muscle (PSE) are thought to be the main cause of DFB. This study is to evaluate correlation between preoperative PSE conditions and angular severity of DFB and to evaluate correlation between preoperative PSE conditions and degree of improvement of DFB obtained by corrective surgery. Materials and Methods: Forty five patients with DFB who took magnetic resonance image (MRI) preoperatively and conducted simple radiography and three-dimensional gait analysis before and 6 months after corrective surgery were included. To determine the severity of PSE atrophy, the ratio between cross-sectional area of PSE and disc was calculated from L1–L2 to L4–L5 on MRI. To assess the degree of fat infiltration, the signal intensity of PSE was measured. Static parameters of spinopelvic segment were measured by simple radiography. Dynamic parameters of spinopelvic and lower limb joints were obtained by three-dimensional gait analysis. Results: In static parameters, thoracic angle was correlated with atrophy and fat infiltration of upper PSE. Thoracic angle was less improved after surgery, as atrophy of upper PSE was more severe. In dynamic parameters, thoracic angle showed correlation with upper PSE conditions, whereas lumbar angle had correlation with middle to lower PSE conditions. While thoracic kyphosis was less improved after surgery, as atrophy of upper PSE was more severe, LL was less improved, as atrophy and fat infiltration of PSE from L1–L2 to L4–L5 were more severe. Conclusions: Severity of atrophy or fat infiltration of PSE showed correlation with degree of angular deformity in patients with DFB and with less improvement after corrective surgery. Dynamic parameters showed more prominent correlation with PSE conditions than static parameters and also showed segmental

  19. A segmentation algorithm for noisy images

    SciTech Connect

    Xu, Y.; Olman, V.; Uberbacher, E.C.

    1996-12-31

    This paper presents a 2-D image segmentation algorithm and addresses issues related to its performance on noisy images. The algorithm segments an image by first constructing a minimum spanning tree representation of the image and then partitioning the spanning tree into sub-trees representing different homogeneous regions. The spanning tree is partitioned in such a way that the sum of gray-level variations over all partitioned subtrees is minimized under the constraints that each subtree has at least a specified number of pixels and two adjacent subtrees have significantly different ``average`` gray-levels. Two types of noise, transmission errors and Gaussian additive noise. are considered and their effects on the segmentation algorithm are studied. Evaluation results have shown that the segmentation algorithm is robust in the presence of these two types of noise.

  20. Raptor Acupuncture for Treating Chronic Degenerative Joint Disease.

    PubMed

    Choi, Keum Hwa; Buhl, Gail; Ponder, Julia

    2016-12-01

    A permanently captive 21-year-old male bald eagle was diagnosed with chronic degenerative joint disease in the right stifle with severe lameness (Grade 5) based on radiography. Clinical signs included decreased movement, vocalization, non weight-bearing on the affected limb, inappetence, depression, and pododermatitis on the left foot (bumblefoot, Grade 3). The eagle was treated with anti-inflammatory or analgesic drugs including carprofen and celecoxib. As there was no observed clinical improvement with any of the treatments, acupuncture treatment was provided. The eagle was treated with dry needle acupuncture once per week for 2 months and biweekly for another 2 months. The Traditional Eastern Medicine diagnosis of this eagle was Bony Bi syndrome. The selected acupuncture points were ST 36, LI 4, BL 40, BL 60, GB 34, and Ba Feng (Table 3). The lameness score improved from Grade 5 to Grade 1 after 4 months of acupuncture treatment. The observed pododermatitis improved from Grade 3 to Grade 0. Symptoms including inappetence and vocalizations were significantly reduced over the 4 month period. There was no significant improvement in the radiographic signs. In conclusion, acupuncture may be a potential medical option for permanently captive raptors having musculoskeletal conditions, such as degenerative joint disease.

  1. Analysis of surgeries for Degenerative lumbarstenosis in elderly patients

    PubMed Central

    Bai, Bin; Li, Yuxin

    2016-01-01

    Objective: To analyze the effect of decompression alone and combined decompression, fusion and internal fixation procedure for degenerative lumbar stenosis in elderly patients. Methods: We reviewed 168 lumbar stenosis patients treated using decompression alone or with combined procedures in the department of orthopaedics of Tianjin 4th Centre Hospital from October 2010 to January 2014. The clinical data including age, gender, procedure type, operation time, follow-up period, blood loss, preoperative and postoperative JOA and ODI scores were recorded. The patients were divided into decompression alone group and combined surgeries group according to the procedure type. Results: The combined surgeries group presented with larger blood loss (p<0.05) and more operation time (p<0.05), compared with the group of decompression alone. The preoperative and postoperative JOA scores were significantly higher (p<0.05), and the ODI scores significantly lower in the decompression alone group (P<0.05), but at the final follow-up, there were no significant difference between the two groups (p>0.05). The complication rate was lower in the group of decompression alone, but there was no significant difference between the two groups (p>0.05). Conclusion: Both the decompression alone and combined surgeries can result in a satisfactory effects in elderly patients with degenerative lumbar spinal stenosis, but the combined surgeries presented with a relatively higher complication rate. PMID:27022361

  2. Handwritten text line segmentation by spectral clustering

    NASA Astrophysics Data System (ADS)

    Han, Xuecheng; Yao, Hui; Zhong, Guoqiang

    2017-02-01

    Since handwritten text lines are generally skewed and not obviously separated, text line segmentation of handwritten document images is still a challenging problem. In this paper, we propose a novel text line segmentation algorithm based on the spectral clustering. Given a handwritten document image, we convert it to a binary image first, and then compute the adjacent matrix of the pixel points. We apply spectral clustering on this similarity metric and use the orthogonal kmeans clustering algorithm to group the text lines. Experiments on Chinese handwritten documents database (HIT-MW) demonstrate the effectiveness of the proposed method.

  3. Feature Learning Based Random Walk for Liver Segmentation

    PubMed Central

    Zheng, Yongchang; Ai, Danni; Zhang, Pan; Gao, Yefei; Xia, Likun; Du, Shunda; Sang, Xinting; Yang, Jian

    2016-01-01

    Liver segmentation is a significant processing technique for computer-assisted diagnosis. This method has attracted considerable attention and achieved effective result. However, liver segmentation using computed tomography (CT) images remains a challenging task because of the low contrast between the liver and adjacent organs. This paper proposes a feature-learning-based random walk method for liver segmentation using CT images. Four texture features were extracted and then classified to determine the classification probability corresponding to the test images. Seed points on the original test image were automatically selected and further used in the random walk (RW) algorithm to achieve comparable results to previous segmentation methods. PMID:27846217

  4. Laser ablation of human atherosclerotic plaque without adjacent tissue injury

    NASA Technical Reports Server (NTRS)

    Grundfest, W. S.; Litvack, F.; Forrester, J. S.; Goldenberg, T.; Swan, H. J. C.

    1985-01-01

    Seventy samples of human cadaver atherosclerotic aorta were irradiated in vitro using a 308 nm xenon chloride excimer laser. Energy per pulse, pulse duration and frequency were varied. For comparison, 60 segments were also irradiated with an argon ion and an Nd:YAG laser operated in the continuous mode. Tissue was fixed in formalin, sectioned and examined microscopically. The Nd:YAG and argon ion-irradiated tissue exhibited a central crater with irregular edges and concentric zones of thermal and blast injury. In contrast, the excimer laser-irradiated tissue had narrow deep incisions with minimal or no thermal injury. These preliminary experiments indicate that the excimer laser vaporizes tissue in a manner different from that of the continuous wave Nd:YAG or argon ion laser. The sharp incision margins and minimal damage to adjacent normal tissue suggest that the excimer laser is more desirable for general surgical and intravascular uses than are the conventionally used medical lasers.

  5. Segmentation and segment connection of obstructed colon

    NASA Astrophysics Data System (ADS)

    Medved, Mario; Truyen, Roel; Likar, Bostjan; Pernus, Franjo

    2004-05-01

    Segmentation of colon CT images is the main factor that inhibits automation of virtual colonoscopy. There are two main reasons that make efficient colon segmentation difficult. First, besides the colon, the small bowel, lungs, and stomach are also gas-filled organs in the abdomen. Second, peristalsis or residual feces often obstruct the colon, so that it consists of multiple gas-filled segments. In virtual colonoscopy, it is very useful to automatically connect the centerlines of these segments into a single colon centerline. Unfortunately, in some cases this is a difficult task. In this study a novel method for automated colon segmentation and connection of colon segments' centerlines is proposed. The method successfully combines features of segments, such as centerline and thickness, with information on main colon segments. The results on twenty colon cases show that the method performs well in cases of small obstructions of the colon. Larger obstructions are mostly also resolved properly, especially if they do not appear in the sigmoid part of the colon. Obstructions in the sigmoid part of the colon sometimes cause improper classification of the small bowel segments. If a segment is too small, it is classified as the small bowel segment. However, such misclassifications have little impact on colon analysis.

  6. Image Segmentation for Improvised Explosive Devices

    DTIC Science & Technology

    2012-12-01

    zj, αj) measuring the similarity between adjacent pixels zi and zj . The function V (zi, αi, zj, αj) results 22 in large values when similar pixels... value distribution. The second and the third rows show the histogram for the object and the background after they were segmented...Images B and C show the directly assembled gray- value histograms for the background (B) and the object (C) . . . . . . . . . . . . . . . . 22 Figure

  7. Cell-Based Therapy for Degenerative Retinal Disease.

    PubMed

    Zarbin, Marco

    2016-02-01

    Stem cell-derived retinal pigment epithelium (RPE) and photoreceptors (PRs) have restored vision in preclinical models of human retinal degenerative disease. This review discusses characteristics of stem cell therapy in the eye and the challenges to clinical implementation that are being confronted today. Based on encouraging results from Phase I/II trials, the first Phase II clinical trials of stem cell-derived RPE transplantation are underway. PR transplant experiments have demonstrated restoration of visual function in preclinical models of retinitis pigmentosa and macular degeneration, but also indicate that no single approach is likely to succeed in overcoming PR loss in all cases. A greater understanding of the mechanisms controlling synapse formation as well as the immunoreactivity of transplanted retinal cells is urgently needed.

  8. Surgical treatment of degenerative osteoarthritis of the fingers.

    PubMed

    Rongières, M

    2013-09-01

    Degenerative osteoarthritis of the long fingers is rare and surgical management is often necessary if there is joint pain, however this indication should not only be based on radiographic imaging. The specific anatomical problems of the metacarpophalangeal (MCP), proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints are described. The surgical approach for each joint is described as well as functional management, in particular that of the extensor apparatus. Mobility should always be preserved for the MCP, arthroplasties are recommended for the PIP except for the index, and arthrodesis for the DIP. The different and most frequently used implants are described as well as the indications and expected results. The indications are discussed in relation to the limited results in the literature as well as the preferences of a panel of French hand surgeons.

  9. A 54-year-old woman with degenerative back pain.

    PubMed

    Tuck, Claire M

    2010-03-01

    Back pain is a common symptom: up to 70% of UK adults experience this symptom by the age of 60 and most have moderate to severe pain. Back pain accounted for 12% of consultations to traditional acupuncturists in 2001 and is one of the most common reasons for consultation with an acupuncturist. This case report concerns a 54-year-old woman with metastatic breast cancer and degenerative lower back pain, which remained painful despite intensive pharmaceutical management and facet joint injection and was ultimately successfully managed with two 30 min acupuncture treatments 2 weeks apart, using eight points on the BL meridians. Acupuncture treatment using tender points was later trialled for neuropathic pain secondary to local recurrence in her mastectomy scar, however this was unsuccessful and inpatient hospice admission for further intensive pharmaceutical management was required.

  10. Regenerative nanomedicine and the treatment of degenerative retinal diseases.

    PubMed

    Zarbin, Marco A; Montemagno, Carlo; Leary, James F; Ritch, Robert

    2012-01-01

    Regenerative medicine deals with the repair or the replacement of tissues and organs using advanced materials and methodologies. Regenerative nanomedicine uses nanoparticles containing gene transcription factors and other modulating molecules that allow reprogramming of cells in vivo as well as nanomaterials to induce selective differentiation of neural progenitor cells and to create neural-mechanical interfaces. In this article, we consider some applications of nanotechnology that may be useful for the treatment of degenerative retinal diseases, for example, use of nanoparticles for drug and gene therapy, use of nanomaterials for neural interfaces and extracellular matrix construction for cell-based therapy and neural prosthetics, and the use of bionanotechnology to re-engineer proteins and cell behavior for regenerative medicine.

  11. Current Status of Lumbar Interbody Fusion for Degenerative Spondylolisthesis

    PubMed Central

    TAKAHASHI, Toshiyuki; HANAKITA, Junya; OHTAKE, Yasufumi; FUNAKOSHI, Yusuke; OICHI, Yuki; KAWAOKA, Taigo; WATANABE, Mizuki

    2016-01-01

    Instrumented lumbar fusion can provide immediate stability and assist in satisfactory arthrodesis in patients who have pain or instability of the lumbar spine. Lumbar adjunctive fusion with decompression is often a good procedure for surgical management of degenerative spondylolisthesis (DS). Among various lumbar fusion techniques, lumbar interbody fusion (LIF) has an advantage in that it maintains favorable lumbar alignment and provides successful fusion with the added effect of indirect decompression. This technique has been widely used and represents an advancement in spinal instrumentation, although the rationale and optimal type of LIF for DS remains controversial. We evaluated the current status and role of LIF in DS treatment, mainly as a means to augment instrumentation. We addressed the basic concept of LIF, its indications, and various types including minimally invasive techniques. It also has acceptable biomechanical features, and offers reconstruction with ideal lumbar alignment. Postsurgical adverse events related to each LIF technique are also addressed. PMID:27169496

  12. Management of behavioral symptoms in progressive degenerative dementias.

    PubMed

    Volicer, Ladislav; Hurley, Ann C

    2003-09-01

    Management of behavioral symptoms of Alzheimer's disease and other progressive degenerative dementias poses continuous challenge to both family and professional caregivers. Behavioral symptoms are complex in nature and require that caregivers understand their presumed causes and intervene appropriately using validated caregiving techniques. Unfortunately, confusing terminology hampers improvement in management techniques. This review attempts to clarify terminology and specifically the behavioral symptoms "agitation" and "resistiveness to care" that require different management techniques. Several conceptual frameworks for behavioral symptoms of dementia are presented. These frameworks include behavioral models, a psychiatric model, and a comprehensive model that combines both behavioral and psychiatric strategies. Using precise terminology consistently and providing care based on a conceptual framework will facilitate the education of caregivers in appropriate techniques for management of behavioral symptoms of dementias.

  13. An improved level set method for vertebra CT image segmentation

    PubMed Central

    2013-01-01

    Background Clinical diagnosis and therapy for the lumbar disc herniation requires accurate vertebra segmentation. The complex anatomical structure and the degenerative deformations of the vertebrae makes its segmentation challenging. Methods An improved level set method, namely edge- and region-based level set method (ERBLS), is proposed for vertebra CT images segmentation. By considering the gradient information and local region characteristics of images, the proposed model can efficiently segment images with intensity inhomogeneity and blurry or discontinuous boundaries. To reduce the dependency on manual initialization in many active contour models and for an automatic segmentation, a simple initialization method for the level set function is built, which utilizes the Otsu threshold. In addition, the need of the costly re-initialization procedure is completely eliminated. Results Experimental results on both synthetic and real images demonstrated that the proposed ERBLS model is very robust and efficient. Compared with the well-known local binary fitting (LBF) model, our method is much more computationally efficient and much less sensitive to the initial contour. The proposed method has also applied to 56 patient data sets and produced very promising results. Conclusions An improved level set method suitable for vertebra CT images segmentation is proposed. It has the flexibility of segmenting the vertebra CT images with blurry or discontinuous edges, internal inhomogeneity and no need of re-initialization. PMID:23714300

  14. On the time-course of adjacent and non-adjacent transposed-letter priming

    PubMed Central

    Ktori, Maria; Kingma, Brechtsje; Hannagan, Thomas; Holcomb, Phillip J.; Grainger, Jonathan

    2014-01-01

    We compared effects of adjacent (e.g., atricle-ARTICLE) and non-adjacent (e.g., actirle-ARTICLE) transposed-letter (TL) primes in an ERP study using the sandwich priming technique. TL priming was measured relative to the standard double-substitution condition. We found significantly stronger priming effects for adjacent transpositions than non-adjacent transpositions (with 2 intervening letters) in behavioral responses (lexical decision latencies), and the adjacent priming effects emerged earlier in the ERP signal, at around 200 ms post-target onset. Non-adjacent priming effects emerged about 50 ms later and were short-lived, being significant only in the 250-300 ms time-window. Adjacent transpositions on the other hand continued to produce priming in the N400 time-window (300-500 ms post-target onset). This qualitatively different pattern of priming effects for adjacent and non-adjacent transpositions is discussed in the light of different accounts of letter transposition effects, and the utility of drawing a distinction between positional flexibility and positional noise. PMID:25364497

  15. Magnetic Interface for Segmented Mirror Assembly

    NASA Technical Reports Server (NTRS)

    Stahl, H.

    2012-01-01

    Newly developed magnetic devices are used to create an interface between adjacent mirror segments so that once assembled, aligned, and phased, the multiple segments will behave functionally equivalent to a monolithic aperture mirror. One embodiment might be a kinematic interface that is reversible so that any number of segments can be pre-assembled, aligned, and phased to facilitate fabrication operations, and then disassembled and reassembled, aligned, and phased in space for operation. The interface mechanism has sufficient stiffness, force, and stability to maintain phasing. The key to producing an interface is the correlated magnetic surface. While conventional magnets are only constrained in one direction -- the direction defined by their point of contact (they are in contact and cannot get any closer) -- correlated magnets can be designed to have constraints in multiple degrees of freedom. Additionally, correlated magnetic surfaces can be designed to have a limited range of action.

  16. Min-cut segmentation of cursive handwriting in tabular documents

    NASA Astrophysics Data System (ADS)

    Davis, Brian L.; Barrett, William A.; Swingle, Scott D.

    2015-01-01

    Handwritten tabular documents, such as census, birth, death and marriage records, contain a wealth of information vital to genealogical and related research. Much work has been done in segmenting freeform handwriting, however, segmentation of cursive handwriting in tabular documents is still an unsolved problem. Tabular documents present unique segmentation challenges caused by handwriting overlapping cell-boundaries and other words, both horizontally and vertically, as "ascenders" and "descenders" overlap into adjacent cells. This paper presents a method for segmenting handwriting in tabular documents using a min-cut/max-flow algorithm on a graph formed from a distance map and connected components of handwriting. Specifically, we focus on line, word and first letter segmentation. Additionally, we include the angles of strokes of the handwriting as a third dimension to our graph to enable the resulting segments to share pixels of overlapping letters. Word segmentation accuracy is 89.5% evaluating lines of the data set used in the ICDAR2013 Handwriting Segmentation Contest. Accuracy is 92.6% for a specific application of segmenting first and last names from noisy census records. Accuracy for segmenting lines of names from noisy census records is 80.7%. The 3D graph cutting shows promise in segmenting overlapping letters, although highly convoluted or overlapping handwriting remains an ongoing challenge.

  17. Preservation of duplicate genes by complementary, degenerative mutations.

    PubMed Central

    Force, A; Lynch, M; Pickett, F B; Amores, A; Yan, Y L; Postlethwait, J

    1999-01-01

    The origin of organismal complexity is generally thought to be tightly coupled to the evolution of new gene functions arising subsequent to gene duplication. Under the classical model for the evolution of duplicate genes, one member of the duplicated pair usually degenerates within a few million years by accumulating deleterious mutations, while the other duplicate retains the original function. This model further predicts that on rare occasions, one duplicate may acquire a new adaptive function, resulting in the preservation of both members of the pair, one with the new function and the other retaining the old. However, empirical data suggest that a much greater proportion of gene duplicates is preserved than predicted by the classical model. Here we present a new conceptual framework for understanding the evolution of duplicate genes that may help explain this conundrum. Focusing on the regulatory complexity of eukaryotic genes, we show how complementary degenerative mutations in different regulatory elements of duplicated genes can facilitate the preservation of both duplicates, thereby increasing long-term opportunities for the evolution of new gene functions. The duplication-degeneration-complementation (DDC) model predicts that (1) degenerative mutations in regulatory elements can increase rather than reduce the probability of duplicate gene preservation and (2) the usual mechanism of duplicate gene preservation is the partitioning of ancestral functions rather than the evolution of new functions. We present several examples (including analysis of a new engrailed gene in zebrafish) that appear to be consistent with the DDC model, and we suggest several analytical and experimental approaches for determining whether the complementary loss of gene subfunctions or the acquisition of novel functions are likely to be the primary mechanisms for the preservation of gene duplicates. For a newly duplicated paralog, survival depends on the outcome of the race between

  18. Does clinical improvement of symptomatic degenerative lumbar disease impact obesity?

    PubMed

    Joseph, Jacob R; Farooqui, Zishaan; Smith, Brandon W; Kahn, Elyne N; Liu, Xilin; La Marca, Frank; Park, Paul

    2017-03-31

    OBJECTIVE Obesity and low-back pain associated with degenerative spondylosis or spondylolisthesis are common comorbid conditions. Many patients report that the pain and disability associated with degenerative lumbar disease are key factors in their inability to lose weight. The aim of this retrospective study was to determine if there is an association between improved functional status and weight loss following a successful transforaminal lumbar interbody fusion (TLIF) procedure. METHODS A retrospective cohort study of patients who underwent single-level TLIF was performed. Inclusion criteria were preoperative body mass index (BMI) greater than 30 kg/m(2), achievement of minimum clinically important difference in the Oswestry Disability Index (ODI, defined as improvement of 15 points), and minimum 1-year postoperative followup BMI. Preoperative and postoperative BMI, ODI, and visual analog scale (VAS) scores were compared. A subgroup analysis of patients who achieved substantial clinical benefit (SCB, defined as a net improvement of 18.8 points on the ODI) was also performed. RESULTS A total of 56 patients met the inclusion criteria. The mean age of the study population was 55.6 ± 13.7 years. The mean preoperative BMI was 34.8 ± 4.6 kg/m(2), the mean preoperative ODI was 66.2 ± 10.1, and the mean preoperative VAS score was 7.1 ± 1.7. The mean change in ODI was -33.1 ± 13.5 (p < 0.01) and the mean change in the VAS score was -4.1 ± 2.1 (p < 0.01). The mean change in BMI was +0.15 ± 2.1 kg/m(2) (range -4.2 to +6.5 kg/m(2); p = 0.6). SCB was achieved in 46 patients on the ODI. The mean preoperative BMI for patients with SCB was 34.8 ± 4.8 kg/m(2), and the mean postoperative BMI was 34.7 ± 5.0 kg/m(2). The mean change in BMI was -0.03 ± 1.9 kg/m(2) (p = 0.9). CONCLUSIONS Despite successful surgical intervention via TLIF with achievement of improved function and pain, obese patients did not have significant change in weight postoperatively.

  19. [Complex outpatient care to patients with osteoarthrosis and degenerative-dystrophic diseases of juxtaarticular soft tissues].

    PubMed

    Saks, L A

    2014-04-01

    The aim of the article is an evaluation of effectiveness of the complex outpatient care to patients with osteoarthrosis and degenerative-dystrophic diseases ofjuxtaarticular soft tissues. Recent researches showed that the key factors of the pathogenesis of diseases were degenerative-dystrophic and inflammatory changes in the synovio-entheseal complex ofparaarticular muscles' tendon. 411 patients with osteoarthrosis of 531 synovial joints and degenerative-dystrophic diseases of periarticular soft tissues underwent sequential corticosteroid therapy combined with hyaluronic acid injections. In 84% of cases positive results were observed.

  20. Degenerative dementias and their medical care in the movies.

    PubMed

    Segers, Kurt

    2007-01-01

    Compared with other neurologic problems, few films have been dedicated to degenerative dementia. To our knowledge, this is the first systematic review about the way in which dementia patients and their medical care are described in films. Twenty-four of the 53 relevant films that were found in online movie databases could be viewed. The author describes the demographics of the characters suffering from dementia, the clinical picture including neuropsychiatric manifestations, diagnostic procedures, medical follow-up, pharmacologic and nonpharmacologic treatment and the attitude of the caregivers. Most characters are played by actors in their seventh or eighth decade. There is an overrepresentation of highly educated people. Although the clinical picture is often accurate, some films suggest that even in the late stages of the disease patients have sudden moments of full insight in their disease. Among the neuropsychiatric signs, activity disturbances and aggressiveness are most often described. Few patients seek medical help, only 2 patients take acetylcholinesterase inhibitors and follow-up is absent for 5 of the 11 relevant patients. Only in 10 of 23 films, the term "Alzheimer" is used. Although there is a growing cinematographic interest in Alzheimer patients, even recent films tend to reinforce therapeutic and even diagnostic nihilism.

  1. Health assessment of environmental pollutants: proliferative and degenerative diseases

    SciTech Connect

    Stuart, B.O.

    1988-12-01

    In order to achieve a balanced approach to risk assessment between carcinogenic and non-carcinogenic health effects one must examine the risk of disease or death in the general population exposed to a particular air pollutant that can be related quantitatively to intensity and duration of exposures (National Academy of Sciences, 1983). Such risk assessment should be based upon careful evaluation of scientific findings of dose-response relationships in the chronically exposed population. Quantitative assessment of environmentally produced disease in man has proven to be complex and demanding. A variety of factors play important roles in this task. As an example, there are induction-latency periods for chronic diseases, including cancer, which may range from five to twenty-five years. The diseases themselves, whether proliferative or degenerative, may follow several stages of progression. There is only sparse epidemiological data on serious health effects that may be due to environmental as compared to occupational exposures. Exposures to chemical or radiological air contaminants do not occur singly but to a multiplicity of agents, and disease processes are frequently markedly affected by the interaction of a variety of factors, particularly that of cigarette smoking. There is growing recognition of potentially sensitive subpopulations, including the elderly and the very young, but adequate techniques for assessing the magnitude of increased risks to these groups have not yet been developed.

  2. Canine degenerative myelopathy: a model of human amyotrophic lateral sclerosis.

    PubMed

    Nardone, Raffaele; Höller, Yvonne; Taylor, Alexandra C; Lochner, Piergiorgio; Tezzon, Frediano; Golaszewski, Stefan; Brigo, Francesco; Trinka, Eugen

    2016-02-01

    Canine degenerative myelopathy (CDM) represents a unique naturally occurring animal model for human amyotrophic lateral sclerosis (ALS) because of similar clinical signs, neuropathologic findings, and involvement of the superoxide dismutase 1 (SOD1) mutation. A definitive diagnosis can only be made postmortem through microscopic detection of axonal degeneration, demyelination and astroglial proliferation, which is more severe in the dorsal columns of the thoracic spinal cord and in the dorsal portion of the lateral funiculus. Interestingly, the muscle acetylcholine receptor complexes are intact in CDM prior to functional impairment, thus suggesting that muscle atrophy in CDM does not result from physical denervation. Moreover, since sensory involvement seems to play an important role in CDM progression, a more careful investigation of the sensory pathology in ALS is also warranted. The importance of SOD1 expression remains unclear, while oxidative stress and denatured ubiquinated proteins appear to play a crucial role in the pathogenesis of CDM. In this updated narrative review we performed a systematic search of the published studies on CDM that may shed light on the pathophysiological mechanisms of human ALS. A better understanding of the factors that determine the disease progression in CDM may be beneficial for the development of effective treatments for ALS.

  3. Station Tour: Russian Segment

    NASA Video Gallery

    Expedition 33 Commander Suni Williams concludes her tour of the International Space Station with a visit to the Russian segment, which includes Zarya, the first segment of the station launched in 1...

  4. Iterative cross section sequence graph for handwritten character segmentation.

    PubMed

    Dawoud, Amer

    2007-08-01

    The iterative cross section sequence graph (ICSSG) is an algorithm for handwritten character segmentation. It expands the cross section sequence graph concept by applying it iteratively at equally spaced thresholds. The iterative thresholding reduces the effect of information loss associated with image binarization. ICSSG preserves the characters' skeletal structure by preventing the interference of pixels that causes flooding of adjacent characters' segments. Improving the structural quality of the characters' skeleton facilitates better feature extraction and classification, which improves the overall performance of optical character recognition (OCR). Experimental results showed significant improvements in OCR recognition rates compared to other well-established segmentation algorithms.

  5. 78 FR 36305 - Proposed Information Collection (Non-Degenerative Arthritis (Including Inflammatory, Autoimmune...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-17

    ..., Crystalline and Infectious Arthritis) and Dysbaric Osteonecrosis Disability Benefits Questionnaire) Activity... disability benefits related to a claimant's diagnosis of a non-degenerative arthritis or osteonecrosis... ] Osteonecrosis Disability Benefits Questionnaire)'' in any correspondence. During the comment period,...

  6. Detection of degenerative change in lateral projection cervical spine x-ray images

    NASA Astrophysics Data System (ADS)

    Jebri, Beyrem; Phillips, Michael; Knapp, Karen; Appelboam, Andy; Reuben, Adam; Slabaugh, Greg

    2015-03-01

    Degenerative changes to the cervical spine can be accompanied by neck pain, which can result from narrowing of the intervertebral disc space and growth of osteophytes. In a lateral x-ray image of the cervical spine, degenerative changes are characterized by vertebral bodies that have indistinct boundaries and limited spacing between vertebrae. In this paper, we present a machine learning approach to detect and localize degenerative changes in lateral x-ray images of the cervical spine. Starting from a user-supplied set of points in the center of each vertebral body, we fit a central spline, from which a region of interest is extracted and image features are computed. A Random Forest classifier labels regions as degenerative change or normal. Leave-one-out cross-validation studies performed on a dataset of 103 patients demonstrates performance of above 95% accuracy.

  7. Clinical and Radiological Comparison of Femur and Fibular Allografts for the Treatment of Cervical Degenerative Disc Diseases

    PubMed Central

    Oh, Hyeong-Seok; Shim, Chan Shik; Lee, Sang-Ho

    2013-01-01

    Objective This consecutive retrospective study was designed to analyze and to compare the efficacy and outcomes of anterior cervical discectomy and fusion (ACDF) using a fibular and femur allograft with anterior cervical plating. Methods A total of 88 consecutive patients suffering from cervical degenerative disc disease (DDD) who were treated with ACDF from September 2007 to August 2010 were enrolled in this study. Thirty-seven patients (58 segments) underwent anterior interbody fusion with a femur allograft, and 51 patients (64 segments) were treated with a fibular allograft. The mean follow-up period was 16.0 (range, 12-25) months in the femur group and 19.5 (range, 14-39) months in the fibular group. Cage fracture and breakage, subsidence rate, fusion rate, segmental angle and height and disc height were assessed by using radiography. Clinical outcomes were assessed using a visual analog scale and neck disability index. Results At 12 months postoperatively, cage fracture and breakage had occurred in 3.4% (2/58) and 7.4% (4/58) of the patients in the femur group, respectively, and 21.9% (14/64) and 31.3% (20/64) of the patients in the fibular group, respectively (p<0.05). Subsidence was noted in 43.1% (25/58) of the femur group and in 50.5% (32/64) of the fibular group. No difference in improvements in the clinical outcome between the two groups was observed. Conclusion The femur allograft showed good results in subsidence and radiologic parameters, and sustained the original cage shape more effectively than the fibular allograft. The present study suggests that the femur allograft may be a good choice as a fusion substitute for the treatment of cervical DDD. PMID:23439721

  8. Degenerative rotator cuff tear in an elderly athlete: a case report

    PubMed Central

    Kazemi, Mohsen

    1999-01-01

    The incidence of rotator cuff tear increases with age. Degenerative rotator cuff tears are commonly seen in athletes above 40 years. These athletes are commonly involved in overhead activities. Repetitive microtrauma is a more important factor in rotator cuff degeneration than acute trauma. Conservative treatment is the mainstay treatment for these injuries. A case report of an elderly athlete who sailed competitively is presented. The clinical and radiographic presentations, management and rehabilitation of degenerative rotator cuff tears are discussed. ImagesFigure 1

  9. Degenerative changes of the sacroiliac auricular joint surface-validation of influential factors.

    PubMed

    Nishi, Keita; Saiki, Kazunobu; Imamura, Takeshi; Okamoto, Keishi; Wakebe, Tetsuaki; Ogami, Keiko; Hasegawa, Takashi; Moriuchi, Takefumi; Sakamoto, Junya; Manabe, Yoshitaka; Tsurumoto, Toshiyuki

    2016-06-24

    The purpose of this study was to clarify the relevance of degenerative changes in the sacroiliac joint (SIJ) and the joints in the lower limb and lumbar spine using age estimation methods. We also examined the shape of the auricular surface to determine the effect of degenerative changes on each joint. A total of 200 iliac auricular surfaces from 100 Japanese male skeletons were examined macroscopically in accordance with conventional methods of age estimation. From the obtained estimated age, we calculated the deflection values, which represented the degree of degenerative changes of the joints. For comparison, we used osteophyte score data of the hip, knee, and zygapophyseal joints in lumbar spines from previous studies which had used the same bone specimens. As a quantitative indicator of auricular surface morphology, we defined the constriction ratio (CR) of the auricular surface and compared the CR values obtained with various measured values. Degenerative changes in the SIJ were positively correlated with those in both the hip joint and zygapophyseal joint, but a correlation with knee joints was found only on the left side. In skeletons from individuals aged ≥60 years as time of death, the CR was significantly different between the group with high scores and those with low scores in both the hip and sacroiliac joints. It has been suggested that degenerative changes in SIJs interact with those in the hip joint and zygapophyseal joint. In addition, the shape of the auricular surface may also be a relevant factor for degenerative changes in these joints.

  10. Defining the inherent stability of degenerative spondylolisthesis: a systematic review.

    PubMed

    Simmonds, Andrea M; Rampersaud, Y Raja; Dvorak, Marcel F; Dea, Nicolas; Melnyk, Angela D; Fisher, Charles G

    2015-08-01

    OBJECT A range of surgical options exists for the treatment of degenerative lumbar spondylolisthesis (DLS). The chosen technique inherently depends on the stability of the DLS. Despite a substantial body of literature dedicated to the outcome analysis of numerous DLS procedures, no consensus has been reached on defining or classifying the disorder with respect to stability or the role that instability should play in a treatment algorithm. The purpose of this study was to define grades of stability and to develop a guide for deciding on the optimal approach in surgically managing patients with DLS. METHODS The authors conducted a qualitative systematic review of clinical or biomechanical analyses evaluating the stability of and surgical outcomes for DLS for the period from 1990 to 2013. Research focused on nondegenerative forms of spondylolisthesis or spinal stenosis without associated DLS was excluded. The primary extracted results were clinical and radiographic parameters indicative of DLS instability. RESULTS The following preoperative parameters are predictors of stability in DLS: restabilization signs (disc height loss, osteophyte formation, vertebral endplate sclerosis, and ligament ossification), no disc angle change or less than 3 mm of translation on dynamic radiographs, and the absence of low-back pain. The validity and magnitude of each parameter's contribution can only be determined through appropriately powered prospective evaluation in the future. Identifying these parameters has allowed for the creation of a preliminary DLS instability classification (DSIC) scheme based on the preoperative assessment of DLS stability. CONCLUSIONS Spinal stability is an important factor to consider in the evaluation and treatment of patients with DLS. Qualitative assessment of the best available evidence revealed clinical and radiographic parameters for the creation of the DSIC, a decision aid to help surgeons develop a method of preoperative evaluation to better

  11. Microsurgical treatment of ophthalmic segment aneurysms.

    PubMed

    Gross, Bradley A; Du, Rose

    2013-08-01

    Ophthalmic segment aneurysms refer to superior hypophyseal artery aneurysms, true ophthalmic artery aneurysms, and their dorsal variant. Indications for treatment of these aneurysms include concerning morphological features, large size, visual loss, or rupture. Although narrow-necked aneurysms are ideal endovascular targets, more complex and larger lesions necessitating adjunctive stent or flow-diversion techniques may be suitably treated with long-lasting, effective clip ligation instead. This is particularly relevant in the consideration of ruptured ophthalmic segment aneurysms. This article provides a depiction of microsurgical treatment of ophthalmic segment aneurysms with an accompanying video demonstration. Emphasis is placed on microsurgical anatomy, the intradural anterior clinoidectomy and clipping technique. The intradural anterior clinoidectomy, demonstrated in detail in our Supplementary video, provides significant added exposure of the ophthalmic segment of the internal carotid artery, allowing for improved aneurysm visualization. In the management of superior hypophyseal artery aneurysms, emphasis is placed on identifying and preserving superior hypophyseal artery perforators, using serial fenestrated straight clips rather than a single right-angled fenestrated clip to obliterate the aneurysm. Post-clipping indocyanine green dye angiography is a crucial tool to confirm aneurysm obliteration and the preservation of the parent vasculature and adjacent superior hypophyseal artery perforators. With careful attention to the nuances of microsurgical clipping of ophthalmic segment aneurysms, rewarding results can be obtained.

  12. Human habenula segmentation using myelin content.

    PubMed

    Kim, Joo-won; Naidich, Thomas P; Ely, Benjamin A; Yacoub, Essa; De Martino, Federico; Fowkes, Mary E; Goodman, Wayne K; Xu, Junqian

    2016-04-15

    The habenula consists of a pair of small epithalamic nuclei located adjacent to the dorsomedial thalamus. Despite increasing interest in imaging the habenula due to its critical role in mediating subcortical reward circuitry, in vivo neuroimaging research targeting the human habenula has been limited by its small size and low anatomical contrast. In this work, we have developed an objective semi-automated habenula segmentation scheme consisting of histogram-based thresholding, region growing, geometric constraints, and partial volume estimation steps. This segmentation scheme was designed around in vivo 3 T myelin-sensitive images, generated by taking the ratio of high-resolution T1w over T2w images. Due to the high myelin content of the habenula, the contrast-to-noise ratio with the thalamus in the in vivo 3T myelin-sensitive images was significantly higher than the T1w or T2w images alone. In addition, in vivo 7 T myelin-sensitive images (T1w over T2*w ratio images) and ex vivo proton density-weighted images, along with histological evidence from the literature, strongly corroborated the in vivo 3 T habenula myelin contrast used in the proposed segmentation scheme. The proposed segmentation scheme represents a step toward a scalable approach for objective segmentation of the habenula suitable for both morphological evaluation and habenula seed region selection in functional and diffusion MRI applications.

  13. Effect of posterior subsidence on cervical alignment after anterior cervical corpectomy and reconstruction using titanium mesh cages in degenerative cervical disease.

    PubMed

    Jang, Jae-Won; Lee, Jung-Kil; Lee, Jung-Heon; Hur, Hyuk; Kim, Tae-Wan; Kim, Soo-Han

    2014-10-01

    Subsidence after anterior cervical reconstruction using a titanium mesh cage (TMC) has been a matter of debate. The authors investigated and analyzed subsidence and its effect on clinical and radiologic parameters after cervical reconstruction using a TMC for degenerative cervical disease. Thirty consecutive patients with degenerative cervical spine disorders underwent anterior cervical corpectomy followed by reconstruction with TMC. Twenty-four patients underwent a single-level corpectomy, and six patients underwent a two-level corpectomy. Clinical outcomes were assessed using a Visual Analogue Scale (VAS), the Japanese Orthopedic Association (JOA) score and the Neck Disability Index (NDI). Fusion status, anterior and posterior subsidence of the TMC, segmental angle (SA) and cervical sagittal angle (CSA) were assessed by lateral and flexion-extension radiographs of the neck. The mean follow-up period was 27.6 months (range, 24 to 49 months). The VAS, NDI and JOA scores were all significantly improved at the last follow-up. No instances of radiolucency or motion-related pseudoarthrosis were detected on radiographic analysis, yielding a fusion rate of 100%. Subsidence occurred in 28 of 30 patients (93.3%). The average anterior subsidence of the cage was 1.4 ± 0.9 mm, and the average posterior subsidence was 2.9 ± 1.2 mm. The SA and CSA at the final follow-up were significantly increased toward a lordotic angle. Anterior cervical reconstruction using TMC and plating in patients with cervical degenerative disease provides good clinical and radiologic outcomes. Cage subsidence occurred frequently, especially at the posterior part of the cage. Despite the prominent posterior subsidence of the TMC, SA and CSA were improved on final follow-up radiographs, suggesting that posterior subsidence may contribute to cervical lordosis.

  14. Impact assisted segmented cutterhead

    DOEpatents

    Morrell, Roger J.; Larson, David A.; Ruzzi, Peter L.

    1992-01-01

    An impact assisted segmented cutterhead device is provided for cutting various surfaces from coal to granite. The device comprises a plurality of cutting bit segments deployed in side by side relationship to form a continuous cutting face and a plurality of impactors individually associated with respective cutting bit segments. An impactor rod of each impactor connects that impactor to the corresponding cutting bit segment. A plurality of shock mounts dampening the vibration from the associated impactor. Mounting brackets are used in mounting the cutterhead to a base machine.

  15. Fully automatic segmentation of complex organ systems: example of trachea, esophagus and heart segmentation in CT images

    NASA Astrophysics Data System (ADS)

    Meyer, Carsten; Peters, Jochen; Weese, Jürgen

    2011-03-01

    Automatic segmentation is a prerequisite to efficiently analyze the large amount of image data produced by modern imaging modalities. Many algorithms exist to segment individual organs or organ systems. However, new clinical applications and the progress in imaging technology will require the segmentation of more and more complex organ systems composed of a number of substructures, e.g., the heart, the trachea, and the esophagus. The goal of this work is to demonstrate that such complex organ systems can be successfully segmented by integrating the individual organs into a general model-based segmentation framework, without tailoring the core adaptation engine to the individual organs. As an example, we address the fully automatic segmentation of the trachea (around its main bifurcation, including the proximal part of the two main bronchi) and the esophagus in addition to the heart with all chambers and attached major vessels. To this end, we integrate the trachea and the esophagus into a model-based cardiac segmentation framework. Specifically, in a first parametric adaptation step of the segmentation workflow, the trachea and the esophagus share global model transformations with adjacent heart structures. This allows to obtain a robust, approximate segmentation for the trachea even if it is only partly inside the field-of-view, and for the esophagus in spite of limited contrast. The segmentation is then refined in a subsequent deformable adaptation step. We obtained a mean segmentation error of about 0.6mm for the trachea and 2.3mm for the esophagus on a database of 23 volumetric cardiovascular CT images. Furthermore, we show by quantitative evaluation that our integrated framework outperforms individual esophagus segmentation, and individual trachea segmentation if the trachea is only partly inside the field-of-view.

  16. Prospective controlled cohort study of Troponin I levels in patients undergoing elective spine surgery for degenerative conditions: Prone versus supine position.

    PubMed

    Macfarlane, A I; Rudd, D; Knight, E; Marshman, L A G; Guazzo, E P; Anderson, D S

    2017-01-01

    Prior studies have suggested that elevated serum Troponin-I (TnI) levels immediately after non-cardiac surgical procedures (8-40%) represent subclinical cardiac stress which independently predicts increased 30-day mortality. Routine post-operative TnI monitoring has therefore been suggested as a standard of care. However, no prior studies have focussed on elective degenerative spine surgery, whilst few have measured pre-op TnI. Further, prolonged prone positioning could represent an additional, independent, cardiac stress. We planned a prospective controlled cohort study of consecutive TnI levels in routine elective spine surgery for degenerative spine conditions, incorporating 3 groups: 'prone<2h', 'prone>2h' and 'supine' positioning. TnI levels (>0.04μg/L) were recorded immediately pre-/post-surgery, and by 24h of surgery. N=120 patients were recruited. Complete results were obtained in 92 (39 supine, 53 prone). No significant between-groups differences were observed in demographic or cardiovascular risk factors. Validated TnI-elevation by 24h was not observed in any group. Spurious elevations were recorded in one 'prone<2h' and one 'prone>2h'. One non-ST segment myocardial infarction (STEMI) occurred on day 7 without TnI elevation by 24h (prone>2h). There was no 30-day mortality.

  17. Segmental degeneration in the cervical spine and associated changes in dorsal root ganglia.

    PubMed

    Boyd-Clark, L C; Briggs, C A; Galea, M P

    2004-09-01

    Degenerative change in cervical segments C5-C7 was documented to determine whether osteo-ligamentous adaptations were age-related. In addition, companion morphological studies were carried out to determine whether parallel changes occurred in related soft tissues, including DRG. Independent of the provoking stimulus, aberrant soft tissue change may be expected with segmental degeneration. Two associations were identified: between the incidence of segmental degeneration and severity of DRG distortion, and between segmental degeneration and DRG inflammatory mast cell density. Peripheral type C cells seemed more susceptible to compression in circumstances of DRG distortion. In light of neuropeptide expression in these cell types, predominant type C cell compression may be clinically relevant in the noxious cascade contributing to the sensation of pain.

  18. Multi-segment coherent beam combining

    SciTech Connect

    Neal, D.R.; Tucker, S.D.; Morgan, R.; Smith, T.G.; Warren, M.E.; Gruetzner, J.K.; Rosenthal, R.R.; Bentley, A.E.

    1994-12-31

    Scaling laser systems to large sizes for power beaming and other applications can sometimes be simplified by combing a number of smaller lasers. However, to fully utilize this scaling, coherent beam combination is necessary. This requires measuring and controlling each beam`s pointing and phase relative to adjacent beams using an adaptive optical system. We have built a sub-scale brass-board to evaluate various methods for beam-combining. It includes a segmented adaptive optic and several different specialized wavefront sensors that are fabricated using diffractive optics methods. We have evaluated a number of different phasing algorithms, including hierarchical and matrix methods, and have demonstrated phasing of several elements. The system is currently extended to a large number of segments to evaluate various scaling methodologies.

  19. Durability of mitral valve repair for mitral regurgitation due to degenerative mitral valve disease.

    PubMed

    David, Tirone E

    2015-09-01

    Degenerative diseases of the mitral valve (MV) are the most common cause of mitral regurgitation in the Western world and the most suitable pathology for MV repair. Several studies have shown excellent long-term durability of MV repair for degenerative diseases. The best follow-up results are obtained with isolated prolapse of the posterior leaflet, however even with isolated prolapse of the anterior leaflet or prolapse of both leaflets the results are gratifying, particularly in young patients. The freedom from reoperation on the MV at 15 years exceeds 90% for isolated prolapse of the posterior leaflet and it is around 70-85% for prolapse of the anterior leaflet or both leaflets. The degree of degenerative change in the MV also plays a role in durability of MV repair. Most studies have used freedom from reoperation to assess durability of the repair but some studies that examined valve function late after surgery suggest that recurrent mitral regurgitation is higher than estimated by freedom from reoperation. We can conclude that MV repair for degenerative mitral regurgitation is associated with low probability of reoperation for up to two decades after surgery. However, almost one-third of the patients develop recurrent moderate or severe mitral regurgitation suggesting that surgery does not arrest the degenerative process.

  20. Hospital benefit segmentation.

    PubMed

    Finn, D W; Lamb, C W

    1986-12-01

    Market segmentation is an important topic to both health care practitioners and researchers. The authors explore the relative importance that health care consumers attach to various benefits available in a major metropolitan area hospital. The purposes of the study are to test, and provide data to illustrate, the efficacy of one approach to hospital benefit segmentation analysis.

  1. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 56.9103 Section..., Hauling, and Dumping Traffic Safety § 56.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  2. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Clearance on adjacent tracks. 57.9103 Section..., Hauling, and Dumping Traffic Safety § 57.9103 Clearance on adjacent tracks. Railcars shall not be left on side tracks unless clearance is provided for traffic on adjacent tracks....

  3. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2011-10-01 2011-10-01 false Signals at adjacent control points....

  4. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., INSPECTION, MAINTENANCE, AND REPAIR OF SIGNAL AND TRAIN CONTROL SYSTEMS, DEVICES, AND APPLIANCES Traffic Control Systems Standards § 236.404 Signals at adjacent control points. Signals at adjacent controlled... 49 Transportation 4 2010-10-01 2010-10-01 false Signals at adjacent control points....

  5. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  6. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  7. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  8. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  9. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Puget Sound and adjacent waters... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Thirteenth District § 80.1395 Puget Sound and adjacent waters. The 72 COLREGS shall apply on all waters of Puget Sound and adjacent waters, including Lake...

  10. Sagittal spinopelvic parameters in 2-level lumbar degenerative spondylolisthesis

    PubMed Central

    Wang, Tao; Wang, Hui; Liu, Huan; Ma, Lei; Liu, Feng-Yu; Ding, Wen-Yuan

    2016-01-01

    Abstract The purpose of our study is to evaluate sagittal parameters in 2-level lumbar degenerative spondylolisthesis (DS) (TLDS). A total of 15 patients with TLDS, 40 patients with single-level DS (SLDS), and 30 normal volunteers as control were included in our study. All subjects performed on full spine X-ray. Two categorized data were analyzed: patient characteristics—age, sex, body mass index, radiographic parameters-pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), sacral slope (SS), PI–LL, Cobb between the fifth thoracic vertebral and 12th thoracic vertebral (T5–T12), sagittal vertical axis (SVA) Cobb angle of spondylolisthesis level (CSL), ratio of PT to SS (PT/SS), CSL/LL, variation trend of SS over PI, and LL over PI. The PI (73.1° vs 52.9°), SS (50.8° vs 32.2°), LL (53.1° vs 46.9°), SVA (66.1 vs 22.0 mm), PI–LL (20.0° vs 6.0°), and CSL (23.6° vs 20.0°) in TLDS were significantly larger than these in SLDS. The PI (73.1° vs 40.6°), PT (22.3° vs 17.1°), SS (50.8° vs 23.5°), LL (53.1° vs 32.5°), PI–LL (20.0° vs 8.1°), and SVA (66.1 vs 17.0 mm) in TLDS were significantly larger than those in the normal group (NG). The PI (52.9° vs 40.6°), PT (21.0° vs 17.1°), SS (32.2° vs 23.5°), LL (46.9° vs 32.5°), and SVA (22.0 vs 17.0 mm) in SLDS were significantly higher than those in NG. However, PT/SS (44.0%), LL over PI (y = 0.39x + 24.25), SS over PI (y = 10.79 + 0.55x) were lower in TLDS than these in SLDS (63.8%, y = 0.41x + 25, y = 0.65x − 2.09, respectively), and the similar tend between SLDS and NG (74.0%, y = 0.49x + 13.09, y = 0.67x − 3.9, respectively). Our results showed that 2-level lumbar DS, which was caused by multiple-factors, has a severe sagittal imbalance, but single-level has not any. When we plan for surgical selection for 2-level lumbar DS, global sagittal balance must be considered. PMID:27977581

  11. Sacroiliac joint motion in patients with degenerative lumbar spine disorders.

    PubMed

    Nagamoto, Yukitaka; Iwasaki, Motoki; Sakaura, Hironobu; Sugiura, Tsuyoshi; Fujimori, Takahito; Matsuo, Yohei; Kashii, Masafumi; Murase, Tsuyoshi; Yoshikawa, Hideki; Sugamoto, Kazuomi

    2015-08-01

    OBJECT Usually additional anchors into the ilium are necessary in long fusion to the sacrum for degenerative lumbar spine disorders (DLSDs), especially for adult spine deformity. Although the use of anchors is becoming quite common, surgeons must always keep in mind that the sacroiliac (SI) joint is mobile and they should be aware of the kinematic properties of the SI joint in patients with DLSDs, including adult spinal deformity. No previous study has clarified in vivo kinematic changes in the SI joint with respect to patient age, sex, or parturition status or the presence of DLSDs. The authors conducted a study to clarify the mobility and kinematic characteristics of the SI joint in patients with DLSDs in comparison with healthy volunteers by using in vivo 3D motion analysis with voxel-based registration, a highly accurate, noninvasive method. METHODS Thirteen healthy volunteers (the control group) and 20 patients with DLSDs (the DLSD group) underwent low-dose 3D CT of the lumbar spine and pelvis in 3 positions (neutral, maximal trunk flexion, and maximal trunk extension). SI joint motion was calculated by computer processing of the CT images (voxel-based registration). 3D motion of the SI joint was expressed as both 6 df by Euler angles and translations on the coordinate system and a helical axis of rotation. The correlation between joint motion and the cross-sectional area of the trunk muscles was also investigated. RESULTS SI joint motion during trunk flexion-extension was minute in healthy volunteers. The mean rotation angles during trunk flexion were 0.07° around the x axis, -0.02° around the y axis, and 0.16° around the z axis. The mean rotation angles during trunk extension were 0.38° around the x axis, -0.08° around the y axis, and 0.08° around the z axis. During trunk flexion-extension, the largest amount of motion occurred around the x axis. In patients with DLSDs, the mean rotation angles during trunk flexion were 0.57° around the x axis, 0.01

  12. Seismicity in Azerbaijan and Adjacent Caspian Sea

    SciTech Connect

    Panahi, Behrouz M.

    2006-03-23

    So far no general view on the geodynamic evolution of the Black Sea to the Caspian Sea region is elaborated. This is associated with the geological and structural complexities of the region revealed by geophysical, geochemical, petrologic, structural, and other studies. A clash of opinions on geodynamic conditions of the Caucasus region, sometimes mutually exclusive, can be explained by a simplified interpretation of the seismic data. In this paper I analyze available data on earthquake occurrences in Azerbaijan and the adjacent Caspian Sea region. The results of the analysis of macroseismic and instrumental data, seismic regime, and earthquake reoccurrence indicate that a level of seismicity in the region is moderate, and seismic event are concentrated in the shallow part of the lithosphere. Seismicity is mostly intra-plate, and spatial distribution of earthquake epicenters does not correlate with the plate boundaries.

  13. The use of stabilization exercises and movement reeducation to manage pain and improve function in a dancer with focal degenerative joint disease of the spine.

    PubMed

    Hagins, Marshall

    2011-09-01

    Little has been written about rehabilitation of low back pain (LBP) specific to the professional dancer. However, there is a rapidly increasing amount of rehabilitation research related to the care of LBP in the general population that may be applied to the dancer population. The purpose of this case report is to describe the physical therapy management of a 37-year-old female professional dancer with a 5-year history of spinal pain and loss of function in the presence of degenerative joint disease at a single segment (T12-L1). Patient interventions focused on stabilization exercises and movement reeducation. The dancer returned to limited dance performance at 6 weeks. At 5 months she had returned to complete dance function, with pain and functional (Oswestry) levels improved from initial values of 7/10 and 48%, respectively, to 1/10 and 26%.

  14. Novel Insights into Acid-Sensing Ion Channels: Implications for Degenerative Diseases

    PubMed Central

    Zhou, Ren-Peng; Wu, Xiao-Shan; Wang, Zhi-Sen; Xie, Ya-Ya; Ge, Jin-Fang; Chen, Fei-Hu

    2016-01-01

    Degenerative diseases often strike older adults and are characterized by progressive deterioration of cells, eventually leading to tissue and organ degeneration for which limited effective treatment options are currently available. Acid-sensing ion channels (ASICs), a family of extracellular H+-activated ligand-gated ion channels, play critical roles in physiological and pathological conditions. Aberrant activation of ASICs is reported to regulate cell apoptosis, differentiation and autophagy. Accumulating evidence has highlighted a dramatic increase and activation of ASICs in degenerative disorders, including multiple sclerosis, Parkinson’s disease, Huntington’s disease, intervertebral disc degeneration and arthritis. In this review, we have comprehensively discussed the critical roles of ASICs and their potential utility as therapeutic targets in degenerative diseases. PMID:27493834

  15. Bowman lecture on the role of inflammation in degenerative disease of the eye

    PubMed Central

    Forrester, J V

    2013-01-01

    Inflammation, in the pathogenesis of many diseases previously thought to be strictly genetic, degenerative, metabolic, or endocrinologic in aetiology, has gradually entered the framework of a general mechanism of disease. This is exemplified by conditions such as Parkinson's disease, Alzheimer's disease, atherosclerosis, diabetes, and the more recently described Metabolic Syndrome. Chronic inflammatory processes have a significant, if not primary role, in ophthalmic diseases, particularly in retinal degenerative diseases. However, inflammation itself is not easy to define, and some aspects of inflammation may be beneficial, in a process described as ‘para-inflammation' by Medhzitov. In contrast, the damaging effects of inflammation, mediated by pro-inflammatory macrophages through activation of the intracellular protein-signalling complexes, termed inflammasomes, are well recognised and are important therapeutic targets. In this review, the range of inflammatory processes in the eye is evaluated in the context of how these processes impact upon retinal degenerative disease, particularly diabetic retinopathy and age-related macular degeneration. PMID:23288138

  16. A double blind trial with cartilage and bone marrow extract in degenerative gonarthrosis.

    PubMed

    Adler, E; Wolf, E; Taustein, I

    1987-01-01

    A double-blind trial with cartilage and bone-marrow extract (Rumalon A) and placebo (Rumalon B) was carried out on 106 patients with degenerative bilateral gonarthrosis. Favorable results were obtained in 64% of the patients treated with Rumalon A and in only 29% of the placebo group. This difference is statistically significant (p < 0.05). The slight influence of placebo can be related to the psychosomatic effect of injections and/or coincident spontaneous improvement of the gonarthrosis. Cartilage and bone marrow extract increases the therapeutic possibilities in degenerative joint disease. It is easy to administer and practically without side effects.

  17. Regional cerebral blood flow in dialysis encephalopathy and primary degenerative dementia

    SciTech Connect

    Mathew, R.J.; Rabin, P.; Stone, W.J.; Wilson, W.H.

    1985-07-01

    Regional cerebral blood flow (CBF) was measured in patients with dialysis encephalopathy, primary degenerative dementia, dialysis patients with no central nervous system (CNS) complications, and normal controls. Both groups of dialysis patients (with and without CNS complications) demonstrated higher CBF values, and the dementia patients, lower CBF values than the controls. The dialysis patients had lower hematocrit, which correlated inversely with the cerebral blood flow. No such correlations were present in normals and patients with primary degenerative dementia. The dialysis patients and controls obtained similar CBF when the flow values were adjusted for the differences in hematocrit.

  18. Keypoint Transfer Segmentation

    PubMed Central

    Toews, M.; Langs, G.; Wells, W.; Golland, P.

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for the inference of keypoint labels and for image segmentation, where keypoint matches are treated as a latent random variable and are marginalized out as part of the algorithm. We report segmentation results for abdominal organs in whole-body CT and in contrast-enhanced CT images. The accuracy of our method compares favorably to common multi-atlas segmentation while offering a speed-up of about three orders of magnitude. Furthermore, keypoint transfer requires no training phase or registration to an atlas. The algorithm’s robustness enables the segmentation of scans with highly variable field-of-view. PMID:26221677

  19. Pancreas and cyst segmentation

    NASA Astrophysics Data System (ADS)

    Dmitriev, Konstantin; Gutenko, Ievgeniia; Nadeem, Saad; Kaufman, Arie

    2016-03-01

    Accurate segmentation of abdominal organs from medical images is an essential part of surgical planning and computer-aided disease diagnosis. Many existing algorithms are specialized for the segmentation of healthy organs. Cystic pancreas segmentation is especially challenging due to its low contrast boundaries, variability in shape, location and the stage of the pancreatic cancer. We present a semi-automatic segmentation algorithm for pancreata with cysts. In contrast to existing automatic segmentation approaches for healthy pancreas segmentation which are amenable to atlas/statistical shape approaches, a pancreas with cysts can have even higher variability with respect to the shape of the pancreas due to the size and shape of the cyst(s). Hence, fine results are better attained with semi-automatic steerable approaches. We use a novel combination of random walker and region growing approaches to delineate the boundaries of the pancreas and cysts with respective best Dice coefficients of 85.1% and 86.7%, and respective best volumetric overlap errors of 26.0% and 23.5%. Results show that the proposed algorithm for pancreas and pancreatic cyst segmentation is accurate and stable.

  20. Keypoint Transfer Segmentation.

    PubMed

    Wachinger, C; Toews, M; Langs, G; Wells, W; Golland, P

    2015-01-01

    We present an image segmentation method that transfers label maps of entire organs from the training images to the novel image to be segmented. The transfer is based on sparse correspondences between keypoints that represent automatically identified distinctive image locations. Our segmentation algorithm consists of three steps: (i) keypoint matching, (ii) voting-based keypoint labeling, and (iii) keypoint-based probabilistic transfer of organ label maps. We introduce generative models for the inference of keypoint labels and for image segmentation, where keypoint matches are treated as a latent random variable and are marginalized out as part of the algorithm. We report segmentation results for abdominal organs in whole-body CT and in contrast-enhanced CT images. The accuracy of our method compares favorably to common multi-atlas segmentation while offering a speed-up of about three orders of magnitude. Furthermore, keypoint transfer requires no training phase or registration to an atlas. The algorithm's robustness enables the segmentation of scans with highly variable field-of-view.

  1. Segmented ion thruster

    NASA Technical Reports Server (NTRS)

    Brophy, John R. (Inventor)

    1993-01-01

    Apparatus and methods for large-area, high-power ion engines comprise dividing a single engine into a combination of smaller discharge chambers (or segments) configured to operate as a single large-area engine. This segmented ion thruster (SIT) approach enables the development of 100-kW class argon ion engines for operation at a specific impulse of 10,000 s. A combination of six 30-cm diameter ion chambers operating as a single engine can process over 100 kW. Such a segmented ion engine can be operated from a single power processor unit.

  2. Vitamin A Derivatives as Treatment Options for Retinal Degenerative Diseases

    PubMed Central

    Perusek, Lindsay; Maeda, Tadao

    2013-01-01

    The visual cycle is a sequential enzymatic reaction for vitamin A, all-trans-retinol, occurring in the outer layer of the human retina and is essential for the maintenance of vision. The central source of retinol is derived from dietary intake of both retinol and pro-vitamin A carotenoids. A series of enzymatic reactions, located in both the photoreceptor outer segment and the retinal pigment epithelium, transform retinol into the visual chromophore 11-cis-retinal, regenerating visual pigments. Retina specific proteins carry out the majority of the visual cycle, and any significant interruption in this sequence of reactions is capable of causing varying degrees of blindness. Among these important proteins are Lecithin:retinol acyltransferase (LRAT) and retinal pigment epithelium-specific 65-kDa protein (RPE65) known to be responsible for esterification of retinol to all-trans-retinyl esters and isomerization of these esters to 11-cis-retinal, respectively. Deleterious mutations in these genes are identified in human retinal diseases that cause blindness, such as Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP). Herein, we discuss the pathology of 11-cis-retinal deficiency caused by these mutations in both animal disease models and human patients. We also review novel therapeutic strategies employing artificial visual chromophore 9-cis-retinoids which have been employed in clinical trials involving LCA patients. PMID:23857173

  3. Hedgehog signaling pathway function conserved in Tribolium segmentation

    PubMed Central

    Farzana, Laila

    2008-01-01

    In Drosophila, maintenance of parasegmental boundaries and formation of segmental grooves depend on interactions between segment polarity genes. Wingless and Engrailed appear to have similar roles in both short and long germ segmentation, but relatively little is known about the extent to which Hedgehog signaling is conserved. In a companion study to the Tribolium genome project, we analyzed the expression and function of hedgehog, smoothened, patched, and cubitus interruptus orthologs during segmentation in Tribolium. Their expression was largely conserved between Drosophila and Tribolium. Parental RNAi analysis of positive regulators of the pathway (Tc-hh, Tc-smo, or Tc-ci) resulted in small spherical cuticles with little or no evidence of segmental grooves. Segmental Engrailed expression in these embryos was initiated but not maintained. Wingless-independent Engrailed expression in the CNS was maintained and became highly compacted during germ band retraction, providing evidence that derivatives from every segment were present in these small spherical embryos. On the other hand, RNAi analysis of a negative regulator (Tc-ptc) resulted in embryos with ectopic segmental grooves visible during germband elongation but not discernible in the first instar larval cuticles. These transient grooves formed adjacent to Engrailed expressing cells that encircled wider than normal wg domains in the Tc-ptc RNAi embryos. These results suggest that the en–wg–hh gene circuit is functionally conserved in the maintenance of segmental boundaries during germ band retraction and groove formation in Tribolium and that the segment polarity genes form a robust genetic regulatory module in the segmentation of this short germ insect. PMID:18392879

  4. CPCs with segmented absorbers

    SciTech Connect

    Keita, M.; Robertson, H.S. )

    1991-01-01

    One of the most promising means of improving the performance of solar thermal collectors is to reduce the energy lost by the hot absorber. One way to do this, not currently part of the technology, is to recognize that since the absorber is usually not irradiated uniformly, it is therefore possible to construct an absorber of thermally isolated segments, circulate the fluid in sequence from low to high irradiance segments, and reduce loss by improving effective concentration. This procedure works even for ideal concentrators, without violating Winston's theorem. Two equivalent CPC collectors with single and segmented absorber were constructed and compared under actual operating conditions. The results showed that the daily thermal efficiency of the collector with segmented absorber is higher (about 13%) than that of the collector with nonsegmented absorber.

  5. Squaring a Circular Segment

    ERIC Educational Resources Information Center

    Gordon, Russell

    2008-01-01

    Consider a circular segment (the smaller portion of a circle cut off by one of its chords) with chord length c and height h (the greatest distance from a point on the arc of the circle to the chord). Is there a simple formula involving c and h that can be used to closely approximate the area of this circular segment? Ancient Chinese and Egyptian…

  6. GPS Control Segment Improvements

    DTIC Science & Technology

    2015-04-29

    Systems Center GPS Control Segment Improvements Mr. Tim McIntyre GPS Product Support Manager GPS Ops Support and Sustainment Division Peterson...hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...DATE 29 APR 2015 2. REPORT TYPE 3. DATES COVERED 00-00-2015 to 00-00-2015 4. TITLE AND SUBTITLE GPS Control Segment Improvements 5a. CONTRACT

  7. Unsupervised spectral mesh segmentation driven by heterogeneous graphs.

    PubMed

    Theologou, Panagiotis; Pratikakis, Ioannis; Theoharis, Theoharis

    2016-03-21

    A fully automatic mesh segmentation scheme using heterogeneous graphs is presented. We introduce a spectral framework where local geometry affinities are coupled with surface patch affinities. A heterogeneous graph is constructed combining two distinct graphs: a weighted graph based on adjacency of patches of an initial over-segmentation, and the weighted dual mesh graph. The partitioning relies on processing each eigenvector of the heterogeneous graph Laplacian individually, taking into account the nodal set and nodal domain theory. Experiments on standard datasets show that the proposed unsupervised approach outperforms the state-of-the-art unsupervised methodologies and is comparable to the best supervised approaches.

  8. Unsupervised Spectral Mesh Segmentation Driven by Heterogeneous Graphs.

    PubMed

    Theologou, Panagiotis; Pratikakis, Ioannis; Theoharis, Theoharis

    2017-02-01

    A fully automatic mesh segmentation scheme using heterogeneous graphs is presented. We introduce a spectral framework where local geometry affinities are coupled with surface patch affinities. A heterogeneous graph is constructed combining two distinct graphs: a weighted graph based on adjacency of patches of an initial over-segmentation, and the weighted dual mesh graph. The partitioning relies on processing each eigenvector of the heterogeneous graph Laplacian individually, taking into account the nodal set and nodal domain theory. Experiments on standard datasets show that the proposed unsupervised approach outperforms the state-of-the-art unsupervised methodologies and is comparable to the best supervised approaches.

  9. Line segments in homogeneous scalar turbulence

    NASA Astrophysics Data System (ADS)

    Gauding, Michael; Goebbert, Jens Henrik; Hasse, Christian; Peters, Norbert

    2015-09-01

    The local structure of a turbulent scalar field in homogeneous isotropic turbulence is analyzed by direct numerical simulations (DNS) with different Taylor micro-scale based Reynolds numbers between 119 and 529. A novel signal decomposition approach is introduced where the signal of the scalar along a straight line is partitioned into segments based on the local extremal points of the scalar field. These segments are then parameterized by the distance ℓ between adjacent extremal points and the scalar difference Δϕ at the extrema. Both variables are statistical quantities and a joint distribution function of these quantities contains most information to statistically describe the scalar field. It is highlighted that the marginal distribution function of the length becomes independent of Reynolds number when normalized by the mean length ℓm. From a statistical approach, it is further shown that the mean length scales with the Kolmogorov length, which is also confirmed by DNS. For turbulent mixing, the scalar gradient plays a paramount role. Turbulent scalar fields are characterized by cliff-ramp-like structures manifesting the occurrence of localized large scalar gradients. To study turbulent mixing, a segment-based gradient is defined as Δϕ/ℓ. Joint statistics of the length and the segment-based gradient provide novel understanding of cliff-ramp-like structures. Ramp-like structures are unveiled by the asymmetry of the joint distribution function of the segment-based gradient and the length. Cliff-like structures are further analyzed by conditional statistics and it is shown from DNS that the width of cliffs scales with the Kolmogorov length scale.

  10. No publication bias in industry funded clinical trials of degenerative diseases of the spine.

    PubMed

    Son, Colin; Tavakoli, Samon; Bartanusz, Viktor

    2016-03-01

    Industry sponsorship of clinical research of degenerative diseases of the spine has been associated with excessive positive published results as compared to research carried out without industry funding. We sought the rates of publication of clinical trials of degenerative diseases of the spine based on funding source as a possible explanation for this phenomenon. We reviewed all clinical trials registered at clinicaltrials.gov relating to degenerative diseases of the spine as categorized under six medical subject heading terms (spinal stenosis, spondylolisthesis, spondylolysis, spondylosis, failed back surgery syndrome, intervertebral disc degeneration) and with statuses of completed or terminated. These collected studies were categorized as having, or not having, industry funding. Published results for these studies were then sought within the clinicaltrials.gov database itself, PubMed and Google Scholar. One hundred sixty-one clinical trials met these criteria. One hundred nineteen of these trials had industry funding and 42 did not. Of those with industry funding, 45 (37.8%) had identifiable results. Of those without industry funding, 17 (40.5%) had identifiable results. There was no difference in the rates of publication of results from clinical trials of degenerative diseases of the spine no matter the funding source.

  11. Teaching Early Braille Literacy Skills within a Stimulus Equivalence Paradigm to Children with Degenerative Visual Impairments

    ERIC Educational Resources Information Center

    Toussaint, Karen A.; Tiger, Jeffrey H.

    2010-01-01

    Despite the need for braille literacy, there has been little attempt to systematically evaluate braille-instruction programs. The current study evaluated an instructive procedure for teaching early braille-reading skills with 4 school-aged children with degenerative visual impairments. Following a series of pretests, braille instruction involved…

  12. First sternocostal degenerative arthritis with intrarticular fluid collection. A case report.

    PubMed

    Chalazonitis, Athanasios N; Condilis, Nicolas; Tilentzoglou, Anastasia C; Pontikis, John; Tzovara, Joannie

    2006-01-01

    A rare case with clinical condition of first sternocostal degenerative arthritis with intra-articular fluid collection that developed after long-lasting intense exercise (weight-lifting) for twenty years is reported. Imaging findings and differential diagnoses of the case are presented.

  13. Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases

    PubMed Central

    2016-01-01

    Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA), diabetes mellitus (DM), and cardiovascular disease (CVD). Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes) from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described. PMID:27721914

  14. Motor Training in Degenerative Spinocerebellar Disease: Ataxia-Specific Improvements by Intensive Physiotherapy and Exergames

    PubMed Central

    2014-01-01

    The cerebellum is essentially involved in movement control and plays a critical role in motor learning. It has remained controversial whether patients with degenerative cerebellar disease benefit from high-intensity coordinative training. Moreover, it remains unclear by which training methods and mechanisms these patients might improve their motor performance. Here, we review evidence from different high-intensity training studies in patients with degenerative spinocerebellar disease. These studies demonstrate that high-intensity coordinative training might lead to a significant benefit in patients with degenerative ataxia. This training might be based either on physiotherapy or on whole-body controlled videogames (“exergames”). The benefit shown in these studies is equal to regaining one or more years of natural disease progression. In addition, first case studies indicate that even subjects with advanced neurodegeneration might benefit from such training programs. For both types of training, the observed clinical improvements are paralleled by recoveries in ataxia-specific dysfunctions (e.g., multijoint coordination and dynamic stability). Importantly, for both types of training, the retention of the effects seems to depend on the frequency and continuity of training. Based on these studies, we here present preliminary recommendations for clinical practice, and articulate open questions that might guide future studies on neurorehabilitation in degenerative spinocerebellar disease. PMID:24877117

  15. Dietary Phytochemicals: Natural Swords Combating Inflammation and Oxidation-Mediated Degenerative Diseases.

    PubMed

    Islam, Md Asiful; Alam, Fahmida; Solayman, Md; Khalil, Md Ibrahim; Kamal, Mohammad Amjad; Gan, Siew Hua

    2016-01-01

    Cumulatively, degenerative disease is one of the most fatal groups of diseases, and it contributes to the mortality and poor quality of life in the world while increasing the economic burden of the sufferers. Oxidative stress and inflammation are the major pathogenic causes of degenerative diseases such as rheumatoid arthritis (RA), diabetes mellitus (DM), and cardiovascular disease (CVD). Although a number of synthetic medications are used to treat these diseases, none of the current regimens are completely safe. Phytochemicals (polyphenols, carotenoids, anthocyanins, alkaloids, glycosides, saponins, and terpenes) from natural products such as dietary fruits, vegetables, and spices are potential sources of alternative medications to attenuate the oxidative stress and inflammation associated with degenerative diseases. Based on in vitro, in vivo, and clinical trials, some of these active compounds have shown good promise for development into novel agents for treating RA, DM, and CVD by targeting oxidative stress and inflammation. In this review, phytochemicals from natural products with the potential of ameliorating degenerative disease involving the bone, metabolism, and the heart are described.

  16. Hippocampus segmentation using locally weighted prior based level set

    NASA Astrophysics Data System (ADS)

    Achuthan, Anusha; Rajeswari, Mandava

    2015-12-01

    Segmentation of hippocampus in the brain is one of a major challenge in medical image segmentation due to its' imaging characteristics, with almost similar intensity between another adjacent gray matter structure, such as amygdala. The intensity similarity has causes the hippocampus to have weak or fuzzy boundaries. With this main challenge being demonstrated by hippocampus, a segmentation method that relies on image information alone may not produce accurate segmentation results. Therefore, it is needed an assimilation of prior information such as shape and spatial information into existing segmentation method to produce the expected segmentation. Previous studies has widely integrated prior information into segmentation methods. However, the prior information has been utilized through a global manner integration, and this does not reflect the real scenario during clinical delineation. Therefore, in this paper, a locally integrated prior information into a level set model is presented. This work utilizes a mean shape model to provide automatic initialization for level set evolution, and has been integrated as prior information into the level set model. The local integration of edge based information and prior information has been implemented through an edge weighting map that decides at voxel level which information need to be observed during a level set evolution. The edge weighting map shows which corresponding voxels having sufficient edge information. Experiments shows that the proposed integration of prior information locally into a conventional edge-based level set model, known as geodesic active contour has shown improvement of 9% in averaged Dice coefficient.

  17. Extended polyglutamine tracts cause aggregation and structural perturbation of an adjacent beta barrel protein.

    PubMed

    Ignatova, Zoya; Gierasch, Lila M

    2006-05-05

    Formation of fibrillar intranuclear inclusions and related neuropathologies of the CAG-repeat disorders are linked to the expansion of a polyglutamine tract. Despite considerable effort, the etiology of these devastating diseases remains unclear. Although polypeptides with glutamine tracts recapitulate many of the observed characteristics of the gene products with CAG repeats, such as in vitro and in vivo aggregation and toxicity in model organisms, extended polyglutamine segments have also been reported to structurally perturb proteins into which they are inserted. Additionally, the sequence context of a polyglutamine tract has recently been shown to modulate its propensity to aggregate. These findings raise the possibility that indirect influences of the repeat tract on adjacent protein domains are contributory to pathologies. Destabilization of an adjacent domain may lead to loss of function, as well as favoring non-native structures in the neighboring domain causing them to be prone to intermolecular association and consequent aggregation. To explore these phenomena, we have used chimeras of a well studied globular protein and exon 1 of huntingtin. We find that expansion of the polyglutamine segment beyond the pathological threshold (>35 glutamines) results in structural perturbation of the neighboring protein whether the huntingtin exon is N- or C-terminal. Elongation of the polyglutamine region also substantially increases the propensity of the chimera to aggregate, both in vitro and in vivo, and in vitro aggregation kinetics of a chimera with a 53-glutamine repeat follow a nucleation polymerization mechanism with a monomeric nucleus.

  18. Surgical Correction in Patients with Lumbar Degenerative Kyphosis Who Had Low Bone Mineral Density: An Analysis of 40 Patients with a Minimum Follow-Up of Two Years

    PubMed Central

    Kim, Ki Tack; Lee, Sang Hun; Huh, Dae Seok; Son, Eun Seok

    2015-01-01

    Study Design Retrospective study. Purpose To investigate influence of bone mineral density (BMD) on the surgical correction of lumbar degenerative kyphosis (LDK). Overview of Literature No studies so far have reported the influence of BMD on the surgical correction of LDK. Methods Forty LDK patients with more than 2 years follow-up were studied. Pelvic incidence (PI), pelvic tilt, sacral slope, sagittal vertical axis (SVA), lumbar lordosis (LL), and thoracic kyphosis were measured preoperatively, immediate postoperatively and at final follow-up. Adverse outcomes: proximal adjacent fractures, sagittal decompensation, pseudoarthrosis, and cage subsidence were documented. Results There were 37 females and 3 males. Average age was 65.1±4.5 years and mean follow-up was 34.2±16.7 months. 42.5% were Takemitsu type 3 curves, 27.5% type 2, 20.0% type 4 and 10.0% type 1. 37.5% had osteopenia, 40.0% osteoporosis and 22.5% had severe osteoporosis. SVA improved from 237.0±96.7 mm preoperatively to 45.3±41.8 mm postoperatively (p=0.000). LL improved from 10.5°±14.7° to -40.6°±10.9° postoperatively (p=0.000). At final follow-up SVA deteriorated to 89.8±72.2 mm and LL to 34.7°±15.8° (p=0.000). The association between late sagittal decompensation, pseudoarthrosis, or proximal adjacent fractures and osteoporosis was insignificant. The difference between immediate postoperative LL and PI (PIDiff) had a significant association with sagittal decompensation and pseudoarthrosis. Conclusions Osteoporosis did not influence the degree of correction, late sagittal decompensation, proximal adjacent fractures, and pseudoarthrosis in LDK. PIDiff had a significant association with sagittal decompensation and pseudoarthrosis. PMID:25705337

  19. Rediscovering market segmentation.

    PubMed

    Yankelovich, Daniel; Meer, David

    2006-02-01

    In 1964, Daniel Yankelovich introduced in the pages of HBR the concept of nondemographic segmentation, by which he meant the classification of consumers according to criteria other than age, residence, income, and such. The predictive power of marketing studies based on demographics was no longer strong enough to serve as a basis for marketing strategy, he argued. Buying patterns had become far better guides to consumers' future purchases. In addition, properly constructed nondemographic segmentations could help companies determine which products to develop, which distribution channels to sell them in, how much to charge for them, and how to advertise them. But more than 40 years later, nondemographic segmentation has become just as unenlightening as demographic segmentation had been. Today, the technique is used almost exclusively to fulfill the needs of advertising, which it serves mainly by populating commercials with characters that viewers can identify with. It is true that psychographic types like "High-Tech Harry" and "Joe Six-Pack" may capture some truth about real people's lifestyles, attitudes, self-image, and aspirations. But they are no better than demographics at predicting purchase behavior. Thus they give corporate decision makers very little idea of how to keep customers or capture new ones. Now, Daniel Yankelovich returns to these pages, with consultant David Meer, to argue the case for a broad view of nondemographic segmentation. They describe the elements of a smart segmentation strategy, explaining how segmentations meant to strengthen brand identity differ from those capable of telling a company which markets it should enter and what goods to make. And they introduce their "gravity of decision spectrum", a tool that focuses on the form of consumer behavior that should be of the greatest interest to marketers--the importance that consumers place on a product or product category.

  20. Semantic segmentation of multispectral overhead imagery

    NASA Astrophysics Data System (ADS)

    Prasad, Lakshman; Pope, Paul A.; Sentz, Kari

    2016-05-01

    Land cover classification uses multispectral pixel information to separate image regions into categories. Image segmentation seeks to separate image regions into objects and features based on spectral and spatial image properties. However, making sense of complex imagery typically requires identifying image regions that are often a heterogeneous mixture of categories and features that constitute functional semantic units such as industrial, residential, or commercial areas. This requires leveraging both spectral classification and spatial feature extraction synergistically to synthesize such complex but meaningful image units. We present an efficient graphical model for extracting such semantically cohesive regions. We employ an initial hierarchical segmentation of images into features represented as nodes of an attributed graph that represents feature properties as well as their adjacency relations with other features. This provides a framework to group spectrally and structurally diverse features, which are nevertheless semantically cohesive, based on user-driven identifications of features and their contextual relationships in the graph. We propose an efficient method to construct, store, and search an augmented graph that captures nonadjacent vicinity relationships of features. This graph can be used to query for semantic notional units consisting of ontologically diverse features by constraining it to specific query node types and their indicated/desired spatial interaction characteristics. User interaction with, and labeling of, initially segmented and categorized image feature graph can then be used to learn feature (node) and regional (subgraph) ontologies as constraints, and to identify other similar semantic units as connected components of the constraint-pruned augmented graph of a query image.

  1. Cooperative processes in image segmentation

    NASA Technical Reports Server (NTRS)

    Davis, L. S.

    1982-01-01

    Research into the role of cooperative, or relaxation, processes in image segmentation is surveyed. Cooperative processes can be employed at several levels of the segmentation process as a preprocessing enhancement step, during supervised or unsupervised pixel classification and, finally, for the interpretation of image segments based on segment properties and relations.

  2. Segmented heterochromia in scalp hair.

    PubMed

    Yoon, Kyeong Han; Kim, Daehwan; Sohn, Seonghyang; Lee, Won Soo

    2003-12-01

    Segmented heterochromia of scalp hair is characterized by the irregularly alternating segmentation of hair into dark and light bands and is known to be associated with iron deficiency anemia. The authors report the case of an 11-year-old boy with segmented heterochromia associated with iron deficiency anemia. After 11 months of iron replacement, the boy's segmented heterochromic hair recovered completely.

  3. Scorpion image segmentation system

    NASA Astrophysics Data System (ADS)

    Joseph, E.; Aibinu, A. M.; Sadiq, B. A.; Bello Salau, H.; Salami, M. J. E.

    2013-12-01

    Death as a result of scorpion sting has been a major public health problem in developing countries. Despite the high rate of death as a result of scorpion sting, little report exists in literature of intelligent device and system for automatic detection of scorpion. This paper proposed a digital image processing approach based on the floresencing characteristics of Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion. The acquired UV-based images undergo pre-processing to equalize uneven illumination and colour space channel separation. The extracted channels are then segmented into two non-overlapping classes. It has been observed that simple thresholding of the green channel of the acquired RGB UV-based image is sufficient for segmenting Scorpion from other background components in the acquired image. Two approaches to image segmentation have also been proposed in this work, namely, the simple average segmentation technique and K-means image segmentation. The proposed algorithm has been tested on over 40 UV scorpion images obtained from different part of the world and results obtained show an average accuracy of 97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed 1system will eliminate the problem associated with some of the existing manual approaches presently in use for scorpion detection.

  4. Support for context effects on segmentation and segments depends on the context.

    PubMed

    Heffner, Christopher C; Newman, Rochelle S; Idsardi, William J

    2017-04-01

    Listeners must adapt to differences in speech rate across talkers and situations. Speech rate adaptation effects are strong for adjacent syllables (i.e., proximal syllables). For studies that have assessed adaptation effects on speech rate information more than one syllable removed from a point of ambiguity in speech (i.e., distal syllables), the difference in strength between different types of ambiguity is stark. Studies of word segmentation have shown large shifts in perception as a result of distal rate manipulations, while studies of segmental perception have shown only weak, or even nonexistent, effects. However, no study has standardized methods and materials to study context effects for both types of ambiguity simultaneously. Here, a set of sentences was created that differed as minimally as possible except for whether the sentences were ambiguous to the voicing of a consonant or ambiguous to the location of a word boundary. The sentences were then rate-modified to slow down the distal context speech rate to various extents, dependent on three different definitions of distal context that were adapted from previous experiments, along with a manipulation of proximal context to assess whether proximal effects were comparable across ambiguity types. The results indicate that the definition of distal influenced the extent of distal rate effects strongly for both segments and segmentation. They also establish the presence of distal rate effects on word-final segments for the first time. These results were replicated, with some caveats regarding the perception of individual segments, in an Internet-based sample recruited from Mechanical Turk.

  5. Unsupervised motion-based object segmentation refined by color

    NASA Astrophysics Data System (ADS)

    Piek, Matthijs C.; Braspenning, Ralph; Varekamp, Chris

    2003-06-01

    . The presented method has no problems with bifurcations. For the pixel resolution segmentation itself we reclassify pixels such that we optimize an error norm which favour similarly coloured regions and straight edges. SEGMENTATION MEASURE To assist in the evaluation of the proposed algorithm we developed a quality metric. Because the problem does not have an exact specification, we decided to define a ground truth output which we find desirable for a given input. We define the measure for the segmentation quality as being how different the segmentation is from the ground truth. Our measure enables us to evaluate oversegmentation and undersegmentation seperately. Also, it allows us to evaluate which parts of a frame suffer from oversegmentation or undersegmentation. The proposed algorithm has been tested on several typical sequences. CONCLUSIONS In this abstract we presented a new video segmentation method which performs well in the segmentation of multiple independently moving foreground objects from each other and the background. It combines the strong points of both colour and motion segmentation in the way we expected. One of the weak points is that the segmentation method suffers from undersegmentation when adjacent objects display similar motion. In sequences with detailed backgrounds the segmentation will sometimes display noisy edges. Apart from these results, we think that some of the techniques, and in particular the K-regions technique, may be useful for other two-dimensional data segmentation problems.

  6. [Pulmonary segmental mediolytic arteriopathy].

    PubMed

    Müller, A M; Kullmann, H J

    2006-03-01

    Segmental mediolytic arteriopathy (SMA) is defined as non-inflammatory arteriopathy with mediolysis due to segmental loss of media and consecutive formation of vascular gaps. Up to now, less than 40 cases of visceral and cerebral SMA and, to our knowledge, only one case of pulmonary SMA have been reported. We present the history of a 21 year old female patient, admitted to hospital with hemoptysis, but without other symptoms. Apart from two lesions in the sixth and tenth pulmonary segment, documented by CT and interpreted as colliquations, there were no other clinical and laboratory findings. Repeated bronchoscopy supplied no further information. Histomorphology of the resected lesion revealed SMA without evidence of vasculitis. Wegener's disease could be excluded. The aetiology of the disease is still unknown. Acute vasospasm (due to inappropriate reactions to catecholamine or endothelial dysfunction), as well as SMA as a precursor or subtype of fibromuscular dysplasia, are two theories still under discussion.

  7. Phasing a segmented telescope

    NASA Astrophysics Data System (ADS)

    Paykin, Irina; Yacobi, Lee; Adler, Joan; Ribak, Erez N.

    2015-02-01

    A crucial part of segmented or multiple-aperture systems is control of the optical path difference between the segments or subapertures. In order to achieve optimal performance we have to phase subapertures to within a fraction of the wavelength, and this requires high accuracy of positioning for each subaperture. We present simulations and hardware realization of a simulated annealing algorithm in an active optical system with sparse segments. In order to align the optical system we applied the optimization algorithm to the image itself. The main advantage of this method over traditional correction methods is that wave-front-sensing hardware and software are no longer required, making the optical and mechanical system much simpler. The results of simulations and laboratory experiments demonstrate the ability of this optimization algorithm to correct both piston and tip-tilt errors.

  8. Head segmentation in vertebrates

    PubMed Central

    Kuratani, Shigeru; Schilling, Thomas

    2008-01-01

    Classic theories of vertebrate head segmentation clearly exemplify the idealistic nature of comparative embryology prior to the 20th century. Comparative embryology aimed at recognizing the basic, primary structure that is shared by all vertebrates, either as an archetype or an ancestral developmental pattern. Modern evolutionary developmental (Evo-Devo) studies are also based on comparison, and therefore have a tendency to reduce complex embryonic anatomy into overly simplified patterns. Here again, a basic segmental plan for the head has been sought among chordates. We convened a symposium that brought together leading researchers dealing with this problem, in a number of different evolutionary and developmental contexts. Here we give an overview of the outcome and the status of the field in this modern era of Evo-Devo. We emphasize the fact that the head segmentation problem is not fully resolved, and we discuss new directions in the search for hints for a way out of this maze. PMID:20607135

  9. Segmented annular combustor

    DOEpatents

    Reider, Samuel B.

    1979-01-01

    An industrial gas turbine engine includes an inclined annular combustor made up of a plurality of support segments each including inner and outer walls of trapezoidally configured planar configuration extents and including side flanges thereon interconnected by means of air cooled connector bolt assemblies to form a continuous annular combustion chamber therebetween and wherein an air fuel mixing chamber is formed at one end of the support segments including means for directing and mixing fuel within a plenum and a perforated header plate for directing streams of air and fuel mixture into the combustion chamber; each of the outer and inner walls of each of the support segments having a ribbed lattice with tracks slidably supporting porous laminated replaceable panels and including pores therein for distributing combustion air into the combustion chamber while cooling the inner surface of each of the panels by transpiration cooling thereof.

  10. Characterization of degenerative human facet joints and facet joint capsular tissues

    PubMed Central

    Kim, Jae-Sung; Ali, Mir H.; Wydra, Frank; Li, Xin; Hamilton, John L.; An, Howard S.; Cs-Szabo, Gabriella; Andrews, Steven; Moric, Mario; Xiao, Guozhi; Wang, James H-C; Chen, Di; Cavanaugh, John M.; Im, Hee-Jeong

    2015-01-01

    SUMMARY Objective Lumbar facet joint degeneration (FJD) may be an important cause of low back pain (LBP) and sciatica. The goal of this study was to characterize cellular alterations of inflammatory factor expression and neovascularization in human degenerative facet joint capsular (FJC) tissue, defined as the fibrous connective tissue lined with synovium that surrounds the joint. The role of these alterations in FJC tissues in pain stimulation was also assessed. Design Lumbar facet joints (FJs) were obtained from consented patients undergoing spinal reconstruction surgery and cadaveric donors with no medical history of back pain. Histological analyses of the FJ were performed to assess general structure, cellular morphology, and proteoglycan content; immunohistochemistry was used to reveal inflammatory factors and neovascularization. Cytokine antibody array and quantitative real- time polymerase chain reaction (qPCR) were used to determine the production of multiple pro- and anti- inflammatory cytokines, and western blotting (WB) was used to assay for cartilage-degrading enzymes and pain mediators. Studies using ex vivo rat dorsal root ganglion (DRG) co-culture with human FJC tissues were also performed. Results Increased neovascularization, infiltration of inflammatory cells, and pain-related axonal-promoting factors were observed in degenerative FJC tissues surgically obtained from symptomatic subjects; this was not seen in normal donor tissues. Increased angiogenic factor, VEGF, axonal promoting factor (NGF/TrkA) and sensory neuronal distribution were also detected in degenerative FJC tissues from subjects with LBP. qPCR and WB results demonstrated highly upregulated inflammatory cytokines, pain mediators, and cartilage-degrading enzymes in degenerative FJCs compared to normal. The DRG and FJC tissue ex vivo co-culture results demonstrated that degenerative FJCs from subjects reporting severe LBP altered the functional properties of DRG sensory neurons, as

  11. Learning Non-Adjacent Regularities at Age 0 ; 7

    ERIC Educational Resources Information Center

    Gervain, Judit; Werker, Janet F.

    2013-01-01

    One important mechanism suggested to underlie the acquisition of grammar is rule learning. Indeed, infants aged 0 ; 7 are able to learn rules based on simple identity relations (adjacent repetitions, ABB: "wo fe fe" and non-adjacent repetitions, ABA: "wo fe wo", respectively; Marcus et al., 1999). One unexplored issue is…

  12. View of north side from exterior stairs of adjacent building, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of north side from exterior stairs of adjacent building, bottom cut off by fringed buildings, view facing south-southwest - U.S. Naval Base, Pearl Harbor, Industrial X-Ray Building, Off Sixth Street, adjacent to and south of Facility No. 11, Pearl City, Honolulu County, HI

  13. A Study of the Pronunciation of Words Containing Adjacent Vowels.

    ERIC Educational Resources Information Center

    Greif, Ivo P.

    To determine the usefulness of the commonly taught phonics rule, "only pronounce the first vowel in words that contain adjacent vowels" (the VV rule, with the first "v" pronounced with the long vowel sound), two new studies applied it to words with adjacent vowels in several lists and dictionaries. The first study analyzed words containing…

  14. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  15. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Adjacent channel power limits. 90.221 Section 90.221 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND MOBILE RADIO SERVICES General Technical Standards § 90.221 Adjacent channel...

  16. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  17. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  18. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  19. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  20. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  1. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  2. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  3. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... MINES Machinery and Equipment Safety Devices and Maintenance Requirements § 56.14109 Unguarded conveyors with adjacent travelways. Unguarded conveyors next to the travelways shall be equipped with—...

  4. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  5. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Unguarded conveyors with adjacent travelways... conveyors with adjacent travelways. Unguarded conveyors next to travelways shall be equipped with— (a) Emergency stop devices which are located so that a person falling on or against the conveyor can...

  6. a Segment-Based Approach for DTM Derivation of Airborne LIDAR Data

    NASA Astrophysics Data System (ADS)

    Tang, Dejin; Zhou, Xiaoming; Jiang, Jie; Li, Caiping

    2016-06-01

    With the characteristics of LIDAR system, raw point clouds represent both terrain and non-terrain surface. In order to generate DTM, the paper introduces one improved filtering method based on the segment-based algorithms. The method generates segments by clustering points based on surface fitting and uses topological and geometric properties for classification. In the process, three major steps are involved. First, the whole datasets is split into several small overlapping tiles. For each tile, by removing wall and vegetation points, accurate segments are found. The segments from all tiles are assigned unique segment number. In the following step, topological descriptions for the segment distribution pattern and height jump between adjacent segments are identified in each tile. Based on the topology and geometry, segment-based filtering algorithm is performed for classification in each tile. Then, based on the spatial location of the segment in one tile, two confidence levels are assigned to the classified segments. The segments with low confidence level are because of losing geometric or topological information in one tile. Thus, a combination algorithm is generated to detect corresponding parts of incomplete segment from multiple tiles. Then another classification algorithm is performed for these segments. The result of these segments will have high confidence level. After that, all the segments in one tile have high confidence level of classification result. The final DTM will add all the terrain segments and avoid duplicate points. At the last of the paper, the experiment show the filtering result and be compared with the other classical filtering methods, the analysis proves the method has advantage in the precision of DTM. But because of the complicated algorithms, the processing speed is little slower, that is the future improvement which should been researched.

  7. Experimental Verification of Dispersed Fringe Sensing as a Segment Phasing Technique using the Keck Telescope

    NASA Technical Reports Server (NTRS)

    Shi, Fang; Chanan, Gary; Ohara, Catherine; Troy, Mitchell; Redding, David C.

    2004-01-01

    Dispersed fringe sensing (DFS) is an efficient and robust method for coarse phasing of segmented primary mirrors (from one quarter of a wavelength to as much as the depth of focus of a single segment, typically several tens of microns). Unlike phasing techniques currently used for ground-based segmented telescopes, DFS does not require the use of edge sensors in order to sense changes in the relative heights of adjacent segments; this makes it particularly well suited for phasing of space-borne segmented telescopes, such as the James Webb Space Telescope. We validate DFS by using it to measure the piston errors of the segments of one of the Keck telescopes. The results agree with those of the Shack-Hartmann-based phasing scheme currently in use at Keck to within 2% over a range of initial piston errors of +/-16 (mu)m.

  8. Cast segment evaluation

    NASA Technical Reports Server (NTRS)

    Diem, H. G.; Studhalter, W. R.

    1971-01-01

    Evaluation program to determine feasibility of fabricating segmented rocket engine thrust chambers using low cost, lightweight castings extends state of the art in areas of casting size and complexity, and in ability to provide thin sections and narrow, deep, cooling channels. Related developments are discussed.

  9. [Segmental testicular infarction].

    PubMed

    Ripa Saldías, L; Guarch Troyas, R; Hualde Alfaro, A; de Pablo Cárdenas, A; Ruiz Ramo, M; Pinós Paul, M

    2006-02-01

    We report the case of a 47 years old man previously diagnosed of left hidrocele. After having a recent mild left testicular pain, an ultrasonografic study revealed a solid hipoecoic testicular lesion rounded by a big hidrocele, suggesting a testicular neoplasm. Radical inguinal orchiectomy was made and pathologic study showed segmental testicular infarction. No malignancy was found. We review the literature of the topic.

  10. Segmentation and Impoverished Youth.

    ERIC Educational Resources Information Center

    Friedman, Judith J.; Friedman, Samuel R.

    1986-01-01

    The following characteristics of jobs held by impoverished youth who applied for a job training program were examined: (1) benefits; (2) skills; (3) career ladders; and (4) unionization. Results imply that segmentation models are not fruitful as guides to labor market experiences of youth at the bottom of wage scale. Other studies were also…

  11. Automatic segmentation of leg bones by using active contours.

    PubMed

    Kim, Sunhee; Kim, Youngjun; Park, Sehyung; Lee, Deukhee

    2014-01-01

    In this paper, we present a new active contours model to segment human leg bones in computed tomography images that is based on a variable-weighted combination of local and global intensity. This model can split an object surrounded by both weak and strong boundaries, and also distinguish very adjacent objects with those boundaries. The ability of this model is required for segmentation in medical images, e.g., human leg bones, which are usually composed of highly inhomogeneous objects and where the distances among organs are very close. We developed an evolution equation of a level set function whose zero level set represents a contour. An initial contour is automatically obtained by applying a histogram based multiphase segmentation method. We experimented with computed tomography images from three patients, and demonstrate the efficiency of the proposed method in experimental results.

  12. Neuroimaging and genetic risk for Alzheimer's disease and addiction-related degenerative brain disorders.

    PubMed

    Roussotte, Florence F; Daianu, Madelaine; Jahanshad, Neda; Leonardo, Cassandra D; Thompson, Paul M

    2014-06-01

    Neuroimaging offers a powerful means to assess the trajectory of brain degeneration in a variety of disorders, including Alzheimer's disease (AD). Here we describe how multi-modal imaging can be used to study the changing brain during the different stages of AD. We integrate findings from a range of studies using magnetic resonance imaging (MRI), positron emission tomography (PET), functional MRI (fMRI) and diffusion weighted imaging (DWI). Neuroimaging reveals how risk genes for degenerative disorders affect the brain, including several recently discovered genetic variants that may disrupt brain connectivity. We review some recent neuroimaging studies of genetic polymorphisms associated with increased risk for late-onset Alzheimer's disease (LOAD). Some genetic variants that increase risk for drug addiction may overlap with those associated with degenerative brain disorders. These common associations offer new insight into mechanisms underlying neurodegeneration and addictive behaviors, and may offer new leads for treating them before severe and irreversible neurological symptoms appear.

  13. Electromagnetic fields in the treatment of chronic lower back pain in patients with degenerative disc disease

    PubMed Central

    Arneja, Amarjit S; Kotowich, Alan; Staley, Doug; Summers, Randy; Tappia, Paramjit S

    2016-01-01

    Aim: To examine the effects of low-amplitude, low frequency electromagnetic field therapy (EMF) therapy in patients with persistent chronic lower back pain associated with degenerative disc disease. Design: Double-blind, randomized and placebo controlled. Intervention: EMF using a medical device resonator; control group underwent same procedures, except the device was turned off. Outcome measures: Pain reduction and mobility. Results: Improvements in overall physical health, social functioning and reduction in bodily pain were observed in the EMF group. The pain relief rating scale showed a higher level of pain relief at the target area in the EMF group. An increase in left lateral mobility was seen only in the EMF group. Conclusion: EMF treatment may be of benefit to patients with chronic nonresponsive lower back pain associated with degenerative disc disease. PMID:28031951

  14. Regeneration of the retina: toward stem cell therapy for degenerative retinal diseases.

    PubMed

    Jeon, Sohee; Oh, Il-Hoan

    2015-04-01

    Degenerative retinal diseases affect millions of people worldwide, which can lead to the loss of vision. However, therapeutic approaches that can reverse this process are limited. Recent efforts have allowed the possibility of the stem cell-based regeneration of retinal cells and repair of injured retinal tissues. Although the direct differentiation of pluripotent stem cells into terminally differentiated photoreceptor cells comprises one approach, a series of studies revealed the intrinsic regenerative potential of the retina using endogenous retinal stem cells. Muller glial cells, ciliary pigment epithelial cells, and retinal pigment epithelial cells are candidates for such retinal stem cells that can differentiate into multiple types of retinal cells and be integrated into injured or developing retina. In this review, we explore our current understanding of the cellular identity of these candidate retinal stem cells and their therapeutic potential for cell therapy against degenerative retinal diseases.

  15. High-intensity laser therapy during chronic degenerative tenosynovitis experimentally induced in broiler chickens

    NASA Astrophysics Data System (ADS)

    Fortuna, Damiano; Rossi, Giacomo; Bilotta, Teresa W.; Zati, Allesandro; Gazzotti, Valeria; Venturini, Antonio; Pinna, Stefania; Serra, Christian; Masotti, Leonardo

    2002-10-01

    The aims of this study was the safety and the efficacy of High Intensity Laser Therapy (HILT) on chronic degenerative tenosynovitis. We have effectuated the histological evaluation and seroassay (C reactive protein) on 18 chickens affect by chronic degenerative tenosynovitis experimentally induced. We have been employed a Nd:YAG laser pulsed wave; all irradiated subjects received the same total energy (270 Joule) with a fluence of 7,7 J/cm2 and intensity of 10,7 W/cm2. The histological findings revealed a distinct reduction of the mineralization of the choral matrix, the anti-inflammatory effect of the laser, the hyperplasia of the synoviocytes and ectasia of the lymphatic vessels.

  16. Grading of degenerative disk disease and functional impairment: imaging versus patho-anatomical findings

    PubMed Central

    Wilke, Hans-Joachim

    2008-01-01

    Degenerative instability affecting the functional spinal unit is discussed as a cause of symptoms. The value of imaging signs for assessing the resulting functional impairment is still unclear. To determine the relationship between slight degrees of degeneration and function, we performed a biomechanical study with 18 multisegmental (L2-S2) human lumbar cadaveric specimens. The multidirectional spinal deformation was measured during the continuous application of pure moments of flexion/extension, bilateral bending and rotation in a spine tester. The three flexibility parameters neutral zone, range of motion and neutral zone ratio were evaluated. Different grading systems were used: (1) antero-posterior and lateral radiographs (degenerative disk disease) (2) oblique radiographs (facet joint degeneration) (3) macroscopic and (4) microscopic evaluation. The most reliable correlation was between the grading of microscopic findings and the flexibility parameters; the imaging evaluation was not as informative. PMID:18839226

  17. A fully organic retinal prosthesis restores vision in a rat model of degenerative blindness.

    PubMed

    Maya-Vetencourt, José Fernando; Ghezzi, Diego; Antognazza, Maria Rosa; Colombo, Elisabetta; Mete, Maurizio; Feyen, Paul; Desii, Andrea; Buschiazzo, Ambra; Di Paolo, Mattia; Di Marco, Stefano; Ticconi, Flavia; Emionite, Laura; Shmal, Dmytro; Marini, Cecilia; Donelli, Ilaria; Freddi, Giuliano; Maccarone, Rita; Bisti, Silvia; Sambuceti, Gianmario; Pertile, Grazia; Lanzani, Guglielmo; Benfenati, Fabio

    2017-03-06

    The degeneration of photoreceptors in the retina is one of the major causes of adult blindness in humans. Unfortunately, no effective clinical treatments exist for the majority of retinal degenerative disorders. Here we report on the fabrication and functional validation of a fully organic prosthesis for long-term in vivo subretinal implantation in the eye of Royal College of Surgeons rats, a widely recognized model of retinitis pigmentosa. Electrophysiological and behavioural analyses reveal a prosthesis-dependent recovery of light sensitivity and visual acuity that persists up to 6-10 months after surgery. The rescue of the visual function is accompanied by an increase in the basal metabolic activity of the primary visual cortex, as demonstrated by positron emission tomography imaging. Our results highlight the possibility of developing a new generation of fully organic, highly biocompatible and functionally autonomous photovoltaic prostheses for subretinal implants to treat degenerative blindness.

  18. Lung tumor segmentation in PET images using graph cuts.

    PubMed

    Ballangan, Cherry; Wang, Xiuying; Fulham, Michael; Eberl, Stefan; Feng, David Dagan

    2013-03-01

    The aim of segmentation of tumor regions in positron emission tomography (PET) is to provide more accurate measurements of tumor size and extension into adjacent structures, than is possible with visual assessment alone and hence improve patient management decisions. We propose a segmentation energy function for the graph cuts technique to improve lung tumor segmentation with PET. Our segmentation energy is based on an analysis of the tumor voxels in PET images combined with a standardized uptake value (SUV) cost function and a monotonic downhill SUV feature. The monotonic downhill feature avoids segmentation leakage into surrounding tissues with similar or higher PET tracer uptake than the tumor and the SUV cost function improves the boundary definition and also addresses situations where the lung tumor is heterogeneous. We evaluated the method in 42 clinical PET volumes from patients with non-small cell lung cancer (NSCLC). Our method improves segmentation and performs better than region growing approaches, the watershed technique, fuzzy-c-means, region-based active contour and tumor customized downhill.

  19. Can segmental mobility be increased by cervical arthroplasty?

    PubMed

    Chang, Hsuan-Kan; Chang, Chih-Chang; Tu, Tsung-Hsi; Wu, Jau-Ching; Huang, Wen-Cheng; Fay, Li-Yu; Chang, Peng-Yuan; Wu, Ching-Lan; Cheng, Henrich

    2017-02-01

    OBJECTIVE Many reports have successfully demonstrated that cervical disc arthroplasty (CDA) can preserve range of motion after 1- or 2-level discectomy. However, few studies have addressed the extent of changes in segmental mobility after CDA or their clinical correlations. METHODS Data from consecutive patients who underwent 1-level CDA were retrospectively reviewed. Indications for surgery were medically intractable degenerative disc disease and spondylosis. Clinical outcomes, including visual analog scale (VAS)-measured neck and arm pain, Neck Disability Index (NDI), and Japanese Orthopaedic Association (JOA) scores, were analyzed. Radiographic outcomes, including C2-7 Cobb angle, the difference between pre- and postoperative C2-7 Cobb angle (ΔC2-7 Cobb angle), sagittal vertical axis (SVA), the difference between pre- and postoperative SVA (ΔSVA), segmental range of motion (ROM), and the difference between pre- and postoperative ROM (ΔROM), were assessed for their association with clinical outcomes. All patients underwent CT scanning, by which the presence and severity of heterotopic ossification (HO) were determined during the follow-up. RESULTS A total of 50 patients (mean age 45.6 ± 9.33 years) underwent a 1-level CDA (Prestige LP disc) and were followed up for a mean duration of 27.7 ± 8.76 months. All clinical outcomes, including VAS, NDI, and JOA scores, improved significantly after surgery. Preoperative and postoperative ROM values were similar (mean 9.5° vs 9.0°, p > 0.05) at each indexed level. The mean changes in segmental mobility (ΔROM) were -0.5° ± 6.13°. Patients with increased segmental mobility after surgery (ΔROM > 0°) had a lower incidence of HO and HO that was less severe (p = 0.048) than those whose ΔROM was < 0°. Segmental mobility (ROM) was significantly lower in patients with higher HO grade (p = 0.012), but it did not affect the clinical outcomes. The preoperative and postoperative C2-7 Cobb angles and SVA remained similar

  20. Kidney segmentation in CT sequences using SKFCM and improved GrowCut algorithm

    PubMed Central

    2015-01-01

    Background Organ segmentation is an important step in computer-aided diagnosis and pathology detection. Accurate kidney segmentation in abdominal computed tomography (CT) sequences is an essential and crucial task for surgical planning and navigation in kidney tumor ablation. However, kidney segmentation in CT is a substantially challenging work because the intensity values of kidney parenchyma are similar to those of adjacent structures. Results In this paper, a coarse-to-fine method was applied to segment kidney from CT images, which consists two stages including rough segmentation and refined segmentation. The rough segmentation is based on a kernel fuzzy C-means algorithm with spatial information (SKFCM) algorithm and the refined segmentation is implemented with improved GrowCut (IGC) algorithm. The SKFCM algorithm introduces a kernel function and spatial constraint into fuzzy c-means clustering (FCM) algorithm. The IGC algorithm makes good use of the continuity of CT sequences in space which can automatically generate the seed labels and improve the efficiency of segmentation. The experimental results performed on the whole dataset of abdominal CT images have shown that the proposed method is accurate and efficient. The method provides a sensitivity of 95.46% with specificity of 99.82% and performs better than other related methods. Conclusions Our method achieves high accuracy in kidney segmentation and considerably reduces the time and labor required for contour delineation. In addition, the method can be expanded to 3D segmentation directly without modification. PMID:26356850

  1. Relationship of a Degenerative Tropical Neuropathy to Diet: Report of a Field Survey

    PubMed Central

    Osuntokun, B. O.; Monekosso, G. L.; Wilson, J.

    1969-01-01

    A survey of neurological abnormalities in two Nigerian villages preselected for their differing consumption of cassava has shown that a degenerative neuropathy occurs with relatively high frequency in the village (Ososa) where cassava consumption was high. It is suggested that eating cassava results in exposure to cyanide, as shown by a raised plasma thiocyanate level, and that the latter, together with other factors, may contribute to the pathogenesis of “tropical neuropathy.” PMID:5764702

  2. A Survey of Vitamin D Status in Patients with Degenerative Diseases of the Spine

    PubMed Central

    Zolfaghari, Farid; Faridmoayer, Alireza; Soleymani, Bahram; Mahabadi, Maryam

    2016-01-01

    Study Design Descriptive cross-sectional study. Purpose To determine the prevalence of vitamin D deficiency in patients with degenerative diseases of the spine about to undergo spinal surgery and the relations between such deficiency and potential risk factors. Overview of Literature Vitamin D has a major role in musculoskeletal system health maintenance. Recently, studies on degenerative diseases of the spine have shown a high prevalence of vitamin D deficiency in patients undergoing spine surgery. Methods Serum levels of 25(OH)D were determined by an electrochemiluminescence detection assay. The other variables were determined through relevant questionnaires, and the data was analyzed through analysis of variance, t-test, chi-square and multivariate logistic regression analysis. Results A total of 110 patients were enrolled in the study. The mean serum level of 25(OH)D was 27.45±18.75 ng/mL, and 44.5% of patients showed vitamin D deficiency (25(OH)D<20 ng/mL), with an additional 17.3% of patients having a serum level of 25(OH)D that was insufficient (20≤25(OH)D<30 ng/mL). The prevalence of vitamin D deficiency was significantly higher in the younger age group compared to the older age group (p<0.001) and the ones without a history of taking vitamin D supplements (p=0.013). Compared to men, women showed significantly higher levels of vitamin D (p=0.029). Conclusions A high prevalence of vitamin D deficiency is seen in patients with degenerative diseases of the spine. On the other hand, the conventional risk factors such as old age or female sex alone did not seem to be sufficient in determining the likelihood of deficiency. Thus, it is recommended that vitamin D deficiency prevention strategies comprise a broader spectrum of the population through which such degenerative diseases and their consequences may be prevented or delayed. PMID:27790310

  3. Is excessive running predictive of degenerative hip disease? Controlled study of former elite athletes.

    PubMed Central

    Marti, B.; Knobloch, M.; Tschopp, A.; Jucker, A.; Howald, H.

    1989-01-01

    OBJECTIVE--To determine the effects of regular long distance running on the state of the hips in later life. DESIGN--Retrospective study of a cohort of elite athletes and a group of normal, healthy, untrained controls examined 15 years after initial testing. SETTING--Research project at school for physical education and sports. SUBJECTS--27 Former long distance runners (mean age 42), nine former bobsleigh riders (mean age 42), and 23 normal, healthy, untrained men (mean age 35) who had been examined in 1973 and who agreed to re-examination in 1988. MAIN OUTCOME MEASURE--Radiological evidence of degenerative hip disease in 1988. RESULTS--Physiological and exercise characteristics of all subjects had been recorded in 1973, and in 1988 these measurements were repeated together with radiological examination of the hips. An additive radiological index of hip disease based on grades of subchondral sclerosis, osteophyte formation, and joint space narrowing was significantly increased among runners as compared with bobsleigh riders and untrained controls. After adjustment for age the significant effect of type of sports activity remained (p = 0.032). In multivariate analyses age and milage run in 1973 (97 km/week) emerged as independent, significant, and positive predictors of radiological signs of degenerative hip disease in 1988 (p = 0.017 and p = 0.024 respectively). Among runners alone running pace in 1973 rather than milage run was the stronger predictor of subsequent degenerative hip disease. The milage run in 1988 was not particularly predictive of the radiological index, but endurance in 1988 was inversely related to degenerative hip disease seen radiologically. CONCLUSION--Long term, high intensity, high milage running should not be dismissed as a potential risk factor for premature osteoarthritis of the hip. PMID:2504343

  4. Study of metabolism and energetics in hypogravity: Degenerative effects of prolonged hypogravity

    NASA Technical Reports Server (NTRS)

    Siegel, S. M.

    1976-01-01

    The role of gravity in the formation of rigid, lignified plant cell walls hence to the development of the erect land plant body is examined. An experiment was proposed with a general hypothesis that a chosen plant, a dwarf marigold, would display degenerative changes in mechanical supportive systems under hypogravity because normal lignin-cellulose wall structure fails to develop. Observational and experimental results are given.

  5. Physiotherapy in degenerative cerebellar ataxias: utilisation, patient satisfaction, and professional expertise.

    PubMed

    Fonteyn, Ella M R; Keus, Samyra H J; Verstappen, Carla C P; van de Warrenburg, Bart P C

    2013-12-01

    Physiotherapy plays an important role in the management of patients with degenerative cerebellar ataxias. However, our insight in the quantity and quality of physiotherapy prescription in this group of patients is incomplete. The purposes of this study were to investigate the utilization of physiotherapy and patient satisfaction in patients with degenerative ataxias in The Netherlands and to examine the level of expertise and needs of physiotherapists treating ataxia patients. Questionnaires were sent to members of the Dutch association for patients with degenerative cerebellar ataxias (n = 532). In addition, 181 questionnaires were sent to the physiotherapists who had recently treated the patients who responded. Eventually, 317 questionnaires from patients (60 %) and 114 questionnaires from physiotherapists (63 %) could be used for further analysis. Sixty-four percent of the patients were currently treated by a physiotherapist. Their median treatment duration was 5 years. Nineteen percent of the patients had never been referred, often despite the presence of limitations in daily activities. On the other hand, some participants without reported limitations had received physiotherapy. In general, participants were satisfied with their physiotherapist. The most reported treatment goals were improvement or maintenance of balance, general physical condition, and mobility. Physiotherapists reported lack of ataxia-specific expertise and expressed the need for education and evidence-based guidelines. Referral to and use of physiotherapy in patients with degenerative cerebellar ataxia in The Netherlands are currently inconsistent and not in agreement with the little scientific evidence available. Referral rates are high, but referrals and actual necessity are discrepant; treatment duration is long; and ataxia-specific expertise among physiotherapists is insufficient. Evidence-based recommendations and specific training of physiotherapists are needed.

  6. Indications for spine surgery: validation of an administrative coding algorithm to classify degenerative diagnoses

    PubMed Central

    Lurie, Jon D.; Tosteson, Anna N.A.; Deyo, Richard A.; Tosteson, Tor; Weinstein, James; Mirza, Sohail K.

    2014-01-01

    Study Design Retrospective analysis of Medicare claims linked to a multi-center clinical trial. Objective The Spine Patient Outcomes Research Trial (SPORT) provided a unique opportunity to examine the validity of a claims-based algorithm for grouping patients by surgical indication. SPORT enrolled patients for lumbar disc herniation, spinal stenosis, and degenerative spondylolisthesis. We compared the surgical indication derived from Medicare claims to that provided by SPORT surgeons, the “gold standard”. Summary of Background Data Administrative data are frequently used to report procedure rates, surgical safety outcomes, and costs in the management of spinal surgery. However, the accuracy of using diagnosis codes to classify patients by surgical indication has not been examined. Methods Medicare claims were link to beneficiaries enrolled in SPORT. The sensitivity and specificity of three claims-based approaches to group patients based on surgical indications were examined: 1) using the first listed diagnosis; 2) using all diagnoses independently; and 3) using a diagnosis hierarchy based on the support for fusion surgery. Results Medicare claims were obtained from 376 SPORT participants, including 21 with disc herniation, 183 with spinal stenosis, and 172 with degenerative spondylolisthesis. The hierarchical coding algorithm was the most accurate approach for classifying patients by surgical indication, with sensitivities of 76.2%, 88.1%, and 84.3% for disc herniation, spinal stenosis, and degenerative spondylolisthesis cohorts, respectively. The specificity was 98.3% for disc herniation, 83.2% for spinal stenosis, and 90.7% for degenerative spondylolisthesis. Misclassifications were primarily due to codes attributing more complex pathology to the case. Conclusion Standardized approaches for using claims data to accurately group patients by surgical indications has widespread interest. We found that a hierarchical coding approach correctly classified over 90

  7. Laser ablation of persistent twist cells in Drosophila: muscle precursor fate is not segmentally restricted

    NASA Technical Reports Server (NTRS)

    Farrell, E. R.; Keshishian, H.

    1999-01-01

    In Drosophila the precursors of the adult musculature arise during embryogenesis. These precursor cells have been termed Persistent Twist Cells (PTCs), as they continue to express the transcription factor Twist after that gene ceases expression elsewhere in the mesoderm. In the larval abdomen, the PTCs are associated with peripheral nerves in stereotypic ventral, dorsal, and lateral clusters, which give rise, respectively, to the ventral, dorsal, and lateral muscle fiber groups of the adult. We tested the developmental potential of the PTCs by using a microbeam laser to ablate specific clusters in larvae. We found that the ablation of a single segmental PTC cluster does not usually result in the deletion of the corresponding adult fibers of that segment. Instead, normal or near normal numbers of adult fibers can form after the ablation. Examination of pupae following ablation showed that migrating PTCs from adjacent segments are able to invade the affected segment, replenishing the ablated cells. However, the ablation of homologous PTCs in multiple segments does result in the deletion of the corresponding adult muscle fibers. These data indicate that the PTCs in an abdominal segment can contribute to the formation of muscle fibers in adjacent abdominal segments, and thus are not inherently restricted to the formation of muscle fibers within their segment of origin.

  8. Segmentation in Tardigrada and diversification of segmental patterns in Panarthropoda.

    PubMed

    Smith, Frank W; Goldstein, Bob

    2016-10-31

    The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods. At the other extreme, all tardigrades share a simple segmented body plan that consists of a head and four leg-bearing segments. The modular body plans of panarthropods make them a tractable model for understanding diversification of animal body plans more generally. Here we review results of recent morphological and developmental studies of tardigrade segmentation. These results complement investigations of segmentation processes in other panarthropods and paleontological studies to illuminate the earliest steps in the evolution of panarthropod body plans.

  9. Characterization of a degenerative cardiomyopathy associated with domoic acid toxicity in California sea lions (Zalophus californianus).

    PubMed

    Zabka, T S; Goldstein, T; Cross, C; Mueller, R W; Kreuder-Johnson, C; Gill, S; Gulland, F M D

    2009-01-01

    Domoic acid, produced by marine algae, can cause acute and chronic neurologic sequela in California sea lions (Zalophus californianus) from acute toxicity or sublethal exposure. Eight sea lions, representing acute and chronic cases, both sexes, and all age classes, were selected to demonstrate a concurrent degenerative cardiomyopathy. Critical aspects of characterizing the cardiomyopathy by lesion distribution and morphology were the development of a heart dissection and tissue-trimming protocol and the delineation of the cardiac conducting system by histomorphology and immunohistochemistry for neuron-specific protein gene product 9.5. Histopathologic features and progression of the cardiomyopathy are described, varying from acute to chronic active and mild to severe. The cardiomyopathy is distinguished from other heart lesions in pinnipeds. Based on histopathologic features, immunopositive staining for cleaved caspase-3, and comparison with known, similar-appearing cardiomyopathies, the proposed pathogenesis for the degenerative cardiomyopathy is the primary or at least initial direct interaction of domoic acid with receptors that are suspected to exist in the heart. l-Carnitine, measured in the heart and skeletal muscle, and troponin-I, measured in serum collected at the time of death from additional animals (n = 58), were not predictive of the domoic acid-associated cardiomyopathy. This degenerative cardiomyopathy in California sea lions represents another syndrome beyond central neurologic disease associated with exposure to domoic acid and may contribute to morbidity and mortality.

  10. Bilateral coxofemoral degenerative joint disease in a juvenile male yellow-eyed penguin (Megadyptes antipodes).

    PubMed

    Buckle, Kelly N; Alley, Maurice R

    2011-08-01

    A juvenile, male, yellow-eyed penguin (Megadyptes antipodes) with abnormal stance and decreased mobility was captured, held in captivity for approximately 6 weeks, and euthanized due to continued clinical signs. Radiographically, there was bilateral degenerative joint disease with coxofemoral periarticular osteophyte formation. Grossly, the bird had bilaterally distended, thickened coxofemoral joints with increased laxity, and small, roughened and angular femoral heads. Histologically, the left femoral articular cartilage and subchondral bone were absent, and the remaining femoral head consisted of trabecular bone overlain by fibrin and granulation tissue. There was no gross or histological evidence of infection. The historic, gross, radiographic, and histopathologic findings were most consistent with bilateral aseptic femoral head degeneration resulting in degenerative joint disease. Although the chronicity of the lesions masked the initiating cause, the probable underlying causes of aseptic bilateral femoral head degeneration in a young animal are osteonecrosis and osteochondrosis of the femoral head. To our knowledge, this is the first reported case of bilateral coxofemoral degenerative joint disease in a penguin.

  11. Degenerative spondylolisthesis in ancient and historic skeletons from New Mexico Pueblo sites.

    PubMed

    Merbs, C F

    2001-12-01

    The objective of this study was to identify the presence of degenerative spondylolisthesis in adult Native American skeletons recovered from prehistoric and historic Pueblo sites in New Mexico. The vertebral columns of 491 individuals that were complete enough to allow the necessary observations produced 64 cases, with a total of 74 affected levels. The L5-S1 level was affected most frequently (78%), in contrast to clinical and anatomical studies where the L4-L5 level was usually affected (80%). Age and sex were found to be important factors, with the condition limited to middle and old adults, and occurring in females over males at a ratio of approximately 5:1. Olisthesis was shown to occur only in association with severe osteoarthritis of the zygapophysial joints, but severe osteoarthritis did not always result in olisthesis, particularly in males. Parallel or convergent inferior articular processes were found to increase in frequency in the presence of olisthesis, apparently resulting from degenerative remodeling that produced the olisthesis. The data also suggest that individuals with cranial border shifting in the column may be especially prone to olisthesis. Degenerative olisthesis was also observed in the cervical region.

  12. A Perspective on the Role of the Extracellular Matrix in Progressive Retinal Degenerative Disorders

    PubMed Central

    Al-Ubaidi, Muayyad R.; Naash, Muna I.; Conley, Shannon M.

    2013-01-01

    Progressive inherited retinal degenerative disorders (PIRDDs) are the leading cause of blindness in developed countries, with AMD and RP constituting the majority of PIRDDs. Currently, over 8 million Americans have PIRDDs, and that number is estimated to drastically increase by the end of this decade. Although a mutant protein is expressed starting early during retinal development in patients with PIRDDs, symptoms of retinal degeneration do not manifest until much later. Historically, research has focused on understanding the role a mutation has in the function of a protein and what role the mutant protein has in the disease process. However, it remains unknown why the disease, irrespective of the mutation, manifests clinically much later in life, while cellular indicators of disease (e.g., accumulation of toxic protein products and cell death) occur throughout early and middle life. Herein, we propose that there exists a time point at which the degenerative process is accelerated, leading to the appearance of clinical symptoms. This point is defined by structural disruptions of the extracellular matrix (ECM). Death of a critical number of ECM-maintaining mutant protein–expressing retinal cells contributes to that break point in the degenerative process. Therefore, it is important to understand the changes occurring at the ECM during PIRDDs and to take that into account when therapeutic approaches are designed. PMID:24346621

  13. Surgical referral criteria for degenerative rotator cuff tears: a Delphi questionnaire study.

    PubMed

    Griffiths, Stephanie; Yohannes, A M

    2014-06-01

    Selecting the most appropriate patients to refer for surgery is crucial for high-quality and efficient clinical care. However, there are no specific referral criteria to guide the referral of appropriate patients for rotator cuff repair surgery. The aim of the present study was to design robust surgical referral criteria for patients with degenerative rotator cuff tears using consensus methodology. A two-round Delphi questionnaire was undertaken with a nationally representative sample of 41 specialist shoulder surgeons experienced in rotator cuff repair. Surgical referral criteria for degenerative rotator cuff tear were developed where consensus of at least 70% agreement was achieved. The initial questionnaire consisted of 24 items. Consensus was reached on 14 items, including: severity of pain, functional limitation, the identification of fat atrophy, agreement that a course of physiotherapy should be attempted before surgical referral, and exclusion for those with an active frozen shoulder. However, there was no consensus with regard to the dimensions of the tear. The surgical referral criteria developed were novel and promising for patients with degenerative rotator cuff tears, and further research is required to examine their efficacy.

  14. Leech segmental repeats develop normally in the absence of signals from either anterior or posterior segments

    NASA Technical Reports Server (NTRS)

    Seaver, E. C.; Shankland, M.

    2000-01-01

    We have investigated whether the development of segmental repeats is autonomous in the embryo of the leech Helobdella robusta. The segmental tissues of the germinal band arise from progeny of five stem cells called teloblasts. Asymmetric divisions of the teloblasts form chains of segment founder cells (called primary blast cells) that divide in a stereotypical manner to produce differentiated descendants. Using two distinct techniques, we have looked for potential interactions between neighboring blast cell clones along the anterior-posterior axis. In one technique, we prevented the birth of primary blast cells by injection of DNase I into the teloblast, thereby depriving the last blast cell produced before the ablation of its normal posterior neighbors. We also ablated single blast cells with a laser microbeam, which allowed us to assess potential signals acting on either more anterior or more posterior primary blast cell clones. Our results suggest that interactions along the anterior-posterior axis between neighboring primary blast cell clones are not required for development of normal segmental organization within the blast cell clone. We also examined the possibility that blast cells receive redundant signals from both anterior and posterior neighboring clones and that either is sufficient for normal development. Using double blast cell laser ablations to isolate a primary blast cell clone by removal of both its anterior and its posterior neighbor, we found that the isolated clone still develops normally. These results reveal that the fundamental segmental repeat in the leech embryo, the primary blast cell clone, can develop normally in the apparent absence of signals from adjacent repeats along the anterior-posterior axis.

  15. PIXE analysis of elements in gastric cancer and adjacent mucosa

    NASA Astrophysics Data System (ADS)

    Liu, Qixin; Zhong, Ming; Zhang, Xiaofeng; Yan, Lingnuo; Xu, Yongling; Ye, Simao

    1990-04-01

    The elemental regional distributions in 20 resected human stomach tissues were obtained using PIXE analysis. The samples were pathologically divided into four types: normal, adjacent mucosa A, adjacent mucosa B and cancer. The targets for PIXE analysis were prepared by wet digestion with a pressure bomb system. P, K, Fe, Cu, Zn and Se were measured and statistically analysed. We found significantly higher concentrations of P, K, Cu, Zn and a higher ratio of Cu compared to Zn in cancer tissue as compared with normal tissue, but statistically no significant difference between adjacent mucosa and cancer tissue was found.

  16. Thermoelastic response of thin metal films and their adjacent materials

    SciTech Connect

    Kang, S.; Yoon, Y.; Kim, J.; Kim, W.

    2013-01-14

    A pulsed laser beam applied to a thin metal film is capable of launching an acoustic wave due to thermal expansion. Heat transfer from the thin metal film to adjacent materials can also induce thermal expansion; thus, the properties of these adjacent materials (as well as the thin metal film) should be considered for a complete description of the thermoelastic response. Here, we show that adjacent materials with a small specific heat and large thermal expansion coefficient can generate an enhanced acoustic wave and we demonstrate a three-fold increase in the peak pressure of the generated acoustic wave on substitution of parylene for polydimethylsiloxane.

  17. [The current aspects of the computed tomographic and clinical diagnosis of degenerative changes in the spine of flight personnel].

    PubMed

    Vasil'ev, A Iu; Martynenko, M V; Martynenko, A V; Aleksakhina, T Iu

    1995-01-01

    The paper deals with the modern aspects of the computed tomographic and clinical diagnostics of the degenerative changes in the vertebral column of the pilots. There has been elaborated the classification of degenerative changes with consideration of the present-day requirements of clinical diagnostics and medical examination. The more frequently seen damages of intervertebral disks in the pilots in the form of protrusions and prolapses are indicated, the computed tomographic and clinical characteristics are compared.

  18. Quantifying Quadriceps Muscle Strength in Patients With ACL Injury, Focal Cartilage Lesions, and Degenerative Meniscus Tears

    PubMed Central

    Eitzen, Ingrid; Grindem, Hege; Nilstad, Agnethe; Moksnes, Håvard; Risberg, May Arna

    2016-01-01

    Background: Reduced quadriceps strength influences knee function and increases the risk of knee osteoarthritis. Thus, it is of significant clinical relevance to precisely quantify strength deficits in patients with knee injuries. Purpose: To evaluate isokinetic concentric quadriceps muscle strength torque values, assessed both from peak torque and at specific knee flexion joint angles, in patients with anterior cruciate ligament (ACL) injury, focal cartilage lesions, and degenerative meniscus tears. Study Design: Cohort study; Level of evidence, 3. Methods: Data were synthesized from patients included in 3 previously conducted research projects: 2 prospective cohort studies and 1 randomized controlled trial. At the time of inclusion, all patients were candidates for surgery. Isokinetic concentric quadriceps muscle strength measurements (60 deg/s) were performed at baseline (preoperative status) and after a period of progressive supervised exercise therapy (length of rehabilitation period: 5 weeks for ACL injury, 12 weeks for cartilage lesions and degenerative meniscus). Outcome measures were peak torque and torque at specific knee flexion joint angles from 20° to 70°. All patients had unilateral injuries, and side-to-side deficits were calculated. For comparisons between and within groups, we utilized 1-way analysis of variance and paired t tests, respectively. Results: In total, 250 patients were included. At baseline, cartilage patients had the most severe deficit (39.7% ± 24.3%; P < .001). Corresponding numbers for ACL and degenerative meniscus subjects were 21.7% (±13.2%) and 20.7% (±16.3%), respectively. At retest, there was significant improvement in all groups (P < .001), with remaining deficits of 24.7% (±18.5%) for cartilage, 16.8% (±13.9%) for ACL, and 3.3% (±17.8%) for degenerative meniscus. Peak torque was consistently measured at 60° of knee flexion, whereas the largest mean deficits were measured at 30° at baseline and 70° at retest for the

  19. Segmental arterial mediolysis.

    PubMed

    Chao, Christine P

    2009-09-01

    Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy, which is characterized by dissecting aneurysms resulting from lysis of the outer media of the arterial wall. The most common presentation is abdominal pain and hemorrhage in the elderly. Computed tomography (CT) and angiography imaging findings overlap with various vasculitides and include segmental changes of aneurysm and stenosis. A key distinguishing feature is the presence of dissections, the principle morphologic expression of SAM. Differentiation and exclusion of an inflammatory arteritis is crucial in appropriate management, as immunosuppressants generally used for treatment of vasculitis may be ineffective or even worsen the vasculopathy. Although the disease can be self-limiting without treatment or with conservative medical therapy, the acute process carries a 50% mortality rate and may necessitate urgent surgical and/or endovascular therapy. Prompt recognition and diagnosis are therefore of utmost importance in appropriate management of this rare entity.

  20. Example based lesion segmentation

    NASA Astrophysics Data System (ADS)

    Roy, Snehashis; He, Qing; Carass, Aaron; Jog, Amod; Cuzzocreo, Jennifer L.; Reich, Daniel S.; Prince, Jerry; Pham, Dzung

    2014-03-01

    Automatic and accurate detection of white matter lesions is a significant step toward understanding the progression of many diseases, like Alzheimer's disease or multiple sclerosis. Multi-modal MR images are often used to segment T2 white matter lesions that can represent regions of demyelination or ischemia. Some automated lesion segmentation methods describe the lesion intensities using generative models, and then classify the lesions with some combination of heuristics and cost minimization. In contrast, we propose a patch-based method, in which lesions are found using examples from an atlas containing multi-modal MR images and corresponding manual delineations of lesions. Patches from subject MR images are matched to patches from the atlas and lesion memberships are found based on patch similarity weights. We experiment on 43 subjects with MS, whose scans show various levels of lesion-load. We demonstrate significant improvement in Dice coefficient and total lesion volume compared to a state of the art model-based lesion segmentation method, indicating more accurate delineation of lesions.

  1. Segmenting the Adult Education Market.

    ERIC Educational Resources Information Center

    Aurand, Tim

    1994-01-01

    Describes market segmentation and how the principles of segmentation can be applied to the adult education market. Indicates that applying segmentation techniques to adult education programs results in programs that are educationally and financially satisfying and serve an appropriate population. (JOW)

  2. Market Segmentation for Information Services.

    ERIC Educational Resources Information Center

    Halperin, Michael

    1981-01-01

    Discusses the advantages and limitations of market segmentation as strategy for the marketing of information services made available by nonprofit organizations, particularly libraries. Market segmentation is defined, a market grid for libraries is described, and the segmentation of information services is outlined. A 16-item reference list is…

  3. Functional Segments in Tongue Movement

    ERIC Educational Resources Information Center

    Stone, Maureen; Epstein, Melissa A.; Iskarous, Khalil

    2004-01-01

    The tongue is a deformable object, and moves by compressing or expanding local functional segments. For any single phoneme, these functional tongue segments may move in similar or opposite directions, and may reach target maximum synchronously or not. This paper will discuss the independence of five proposed segments in the production of speech.…

  4. Overall view of tower and adjacent aircraft shelters on flight ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overall view of tower and adjacent aircraft shelters on flight line. View to east. - Plattsburgh Air Force Base, Security Guard Tower, Florida Street at Aircraft Shelters Area, Plattsburgh, Clinton County, NY

  5. Interior building details of Building A, dungeon cell adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Interior building details of Building A, dungeon cell adjacent to northwest cell: granite and brick threshold, poured concrete floors, plastered finished walls, vaulted veiling; northwesterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

  6. 10. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  7. Lock 4 View east of lock wall and adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Lock 4 - View east of lock wall and adjacent roadway built atop tow path. The gate pocket can be seen at center. - Savannah & Ogeechee Barge Canal, Between Ogeechee & Savannah Rivers, Savannah, Chatham County, GA

  8. 1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. A BRICK AND CONCRETE FAN HOUSING ADJACENT TO ONE OF THE ADIT OPENINGS (VIEW TO THE NORTH). - Foster Gulch Mine, Fan Housing, Bear Creek 1 mile Southwest of Town of Bear Creek, Red Lodge, Carbon County, MT

  9. 1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  10. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING SOUTH. GARAGE TO EXTREME LEFT, BUILDING 1 TO EXTREME RIGHT. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  11. View from water showing south facade and adjacent boat slips ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View from water showing south facade and adjacent boat slips (Facility Nos. S375 & S376) - U.S. Naval Base, Pearl Harbor, Boat House, Hornet Avenue at Independence Street, Pearl City, Honolulu County, HI

  12. Cement Leakage into Adjacent Vertebral Body Following Percutaneous Vertebroplasty.

    PubMed

    Park, Jae Hoo; Kim, Hyeun Sung; Kim, Seok Won

    2016-06-01

    Percutaneous vertebroplasty (PV) is a minimally invasive procedure for osteoporotic vertebral compression fractures that fail to respond to conventional conservative treatment. It significantly improves intolerable back pain within hours, and has a low complication rate. Although rare, PV is not free of complications, most of which are directly related to cement leakage. Because of its association with new adjacent fracture, the importance of cement leakage into the adjacent disc space is paramount. Here, we report an interesting case of cement leakage into the adjacent upper vertebral body as well as disc space following PV. To the best of our knowledge, there has been no report of cement leakage into the adjacent vertebral body following PV. This rare case is presented along with a review of the literature.

  13. 15. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. View north from the adjacent B & O railroad bridge of Pier No. 5 and portion of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  14. 7. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. View north from the adjacent B & O railroad bridge of Pier No. 1 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  15. 8. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. View north from the adjacent B & O railroad bridge of Pier No. 2 and portions of the deck and super-structure. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  16. VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF NORTHERN AND EASTERN SIDES FROM PARKING LOT ADJACENT TO BUILDING 199 (POLICE STATION) - U.S. Naval Base, Pearl Harbor, Post Office, Avenue A near Eleventh Avenue, Pearl City, Honolulu County, HI

  17. Basement, room 23, looking southwest into two adjacent offices with ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Basement, room 23, looking southwest into two adjacent offices with soundproof walls and pedestal flooring - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  18. 3. View of north side of house facing from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of north side of house facing from adjacent vacant property. Original wood lap siding and trim is covered by aluminum siding. Recessed side porch is in middle. - 645 South Eighteenth Street (House), Louisville, Jefferson County, KY

  19. View of viaduct, looking SE from roof of adjacent parking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of viaduct, looking SE from roof of adjacent parking garage. - Mulberry Street Viaduct, Spanning Paxton Creek & Cameron Street (State Route 230) at Mulberry Street (State Route 3012), Harrisburg, Dauphin County, PA

  20. 1. Ninth Street (west) facade. Adjacent on the north is ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. Ninth Street (west) facade. Adjacent on the north is the 9th Street facade of 816 E Street. Both buildings were originally one property. - Riley Building, Rendezvous Adult Magazines & Films, 437 Ninth Street, Northwest, Washington, District of Columbia, DC

  1. 6. Detail, vertical guides adjacent to east portal of Tunnel ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Detail, vertical guides adjacent to east portal of Tunnel 28, view to southwest, 135mm lens with electronic flash fill. - Central Pacific Transcontinental Railroad, Tunnel No. 28, Milepost 134.75, Applegate, Placer County, CA

  2. VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LAMP FIXTURE (EXTERIOR) ADJACENT TO ENTRANCE AT SOUTHWEST CORNER OF BUILDING 23, FACING NORTH - Roosevelt Base, Auditorium-Gymnasium, West Virginia Street between Richardson & Reeves Avenues, Long Beach, Los Angeles County, CA

  3. 73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    73. PASSAGE ADJACENT TO ROOM 232, EAST WING, SECOND FLOOR, LOOKING WEST BY NORTHWEST, SHOWING EASTERNMOST ARCH OF FORMER GREAT HALL NORTH ARCADE - Smithsonian Institution Building, 1000 Jefferson Drive, between Ninth & Twelfth Streets, Southwest, Washington, District of Columbia, DC

  4. Detail exterior view looking north showing piping system adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail exterior view looking north showing piping system adjacent to engine house. Gas cooling system is on far right. - Burnsville Natural Gas Pumping Station, Saratoga Avenue between Little Kanawha River & C&O Railroad line, Burnsville, Braxton County, WV

  5. 52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    52. EASTSIDE PLANT: GENERAL VIEW OF GOVERNOR ADJACENT TO GENERATOR - American Falls Water, Power & Light Company, Island Power Plant, Snake River, below American Falls Dam, American Falls, Power County, ID

  6. OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OBLIQUE OF SOUTHWEST END AND SOUTHEAST SIDE, WITH ADJACENT FACILITY 391 IN THE FOREGROUND. - U.S. Naval Base, Pearl Harbor, Joint Intelligence Center, Makalapa Drive in Makalapa Administration Area, Pearl City, Honolulu County, HI

  7. Brick incinerator structure located adjacent to "motor courts." This example ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Brick incinerator structure located adjacent to "motor courts." This example is located between Buildings 26 and 27. Facing northeast - Harbor Hills Housing Project, 26607 Western Avenue, Lomita, Los Angeles County, CA

  8. 7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. August, 1970 9 ORANGE STREET, ADJACENT TO UNITARIAN CHURCH (NOT IN STUDY AREA) - Orange & Union Streets Neighborhood Study, 8-31 Orange Street, 9-21 Union Street & Stone Alley, Nantucket, Nantucket County, MA

  9. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOME, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes, Building No. 16, 488-514 Techwood Drive, Atlanta, Fulton County, GA

  10. 72. View of reservoir adjacent to south wall of blowing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    72. View of reservoir adjacent to south wall of blowing engine house where water from furnaces was allowed to cool. - Sloss-Sheffield Steel & Iron, First Avenue North Viaduct at Thirty-second Street, Birmingham, Jefferson County, AL

  11. Learning at a distance II. Statistical learning of non-adjacent dependencies in a non-human primate.

    PubMed

    Newport, Elissa L; Hauser, Marc D; Spaepen, Geertrui; Aslin, Richard N

    2004-09-01

    In earlier work we have shown that adults, infants, and cotton-top tamarin monkeys are capable of computing the probability with which syllables occur in particular orders in rapidly presented streams of human speech, and of using these probabilities to group adjacent syllables into word-like units. We have also investigated adults' learning of regularities among elements that are not adjacent, and have found strong selectivities in their ability to learn various kinds of non-adjacent regularities. In the present paper we investigate the learning of these same non-adjacent regularities in tamarin monkeys, using the same materials and familiarization methods. Three types of languages were constructed. In one, words were formed by statistical regularities between non-adjacent syllables. Words contained predictable relations between syllables 1 and 3; syllable 2 varied. In a second type of language, words were formed by statistical regularities between non-adjacent segments. Words contained predictable relations between consonants; the vowels varied. In a third type of language, also formed by regularities between non-adjacent segments, words contained predictable relations between vowels; the consonants varied. Tamarin monkeys were exposed to these languages in the same fashion as adults (21 min of exposure to a continuous speech stream) and were then tested in a playback paradigm measuring spontaneous looking (no reinforcement). Adult subjects learned the second and third types of language easily, but failed to learn the first. However, tamarin monkeys showed a different pattern, learning the first and third type of languages but not the second. These differences held up over multiple replications, using different sounds instantiating each of the patterns. These results suggest differences among learners in the elementary units perceived in speech (syllables, consonants, and vowels) and/or the distance over which such units can be related, and therefore differences

  12. Comparative Analysis of Interbody Cages Versus Tricortical Graft with Anterior Plate Fixation for Anterior Cervical Discectomy and Fusion in Degenerative Cervical Disc Disease

    PubMed Central

    Singh, Pritish; Shekhawat, Vishal

    2016-01-01

    Introduction Multiple techniques and modalities of fixation are used in Anterior Cervical Discectomy and interbody Fusion (ACDF), each with some merit and demerit against others. Such pool of techniques reflects lack of a consensus method conducive to uniformly good results. Aim A prospective study was done to analyse safety and efficacy of tricortical autograft and anterior cervical plate (Group A) with cylindrical titanium cage filled with cancellous bone (Group B) in procedure of ACDF for single level degenerative cervical disc disease. Materials and Methods Twenty patients with degenerative cervical disc disease were included in study for ACDF. After a computer generated randomisation, ten patients (10 segments) were operated with anterior locking plating and tricortical iliac crest graft (Group A, Tricortical graft group), while ten patients(10 segments) were operated with standalone cylindrical titanium cages filled with cancellous bone harvested using minimally invasive methods (Group B, Cage group) from April 2012 to May 2015. Odoms’s criteria, visual pain analogue score and sequential plain radiographs were obtained to assess for clinic-radiological outcome. Results According to Odom’s system of functional assessment, 9 patients from each group (90%) experienced good to excellent functional recovery and 9 of 10 (90%) patients of each groups were satisfied with outcome. In both groups, relief in neck pain or arm pain was similar without any statistical difference as assessed by visual analogue score. Fusion was present in 10 of 10 (100%) patients in tricortical graft group and 10 of 10 (100%) in cage group at the end of 6 months. There was no implant related complications in cage group. Transient postoperative dysphagia was recorded in 3 patients (2 in Group A and 1 in group B), which resolved within 3 days. In tricortical graft group, graft collapse and partial extrusion was detected in one patient, which did not correspond with good results obtained

  13. Metal content of biopsies adjacent to dental cast alloys.

    PubMed

    Garhammer, Pauline; Schmalz, G; Hiller, K-A; Reitinger, T

    2003-06-01

    Single case reports indicate that components of dental alloys accumulate in the adjacent soft tissue of the oral cavity. However, data on a wider range of dental alloys and patient groups are scarce. Therefore, the aim of the present study was to examine the metal content of oral tissues adjacent to dental alloys showing persisting signs of inflammation or other discoloration (affected sites) and of healthy control sites with no adjacent metal restoration in 28 patients. The composition of the adjacent alloys was analyzed and compared to the alloy components in the affected sites. Tissue analysis was performed using atomic absorption spectroscopy. Alloy analysis was performed with energy-dispersive X-ray analysis. In the affected sites, the metals Ag, Au, Cu, and Pd prevailed compared to control sites, reflecting the frequency distribution of single metals in the adjacent alloys. In most cases (84%), at least one of the analyzed metals was a component of the alloy and also detected in the tissue. Metal components from almost all dental cast alloys can be detected in adjacent tissue.

  14. Split-remerge method for eliminating processing window artifacts in recursive hierarchical segmentation

    NASA Technical Reports Server (NTRS)

    Tilton, James C. (Inventor)

    2010-01-01

    A method, computer readable storage, and apparatus for implementing recursive segmentation of data with spatial characteristics into regions including splitting-remerging of pixels with contagious region designations and a user controlled parameter for providing a preference for merging adjacent regions to eliminate window artifacts.

  15. Random Walk Based Segmentation for the Prostate on 3D Transrectal Ultrasound Images.

    PubMed

    Ma, Ling; Guo, Rongrong; Tian, Zhiqiang; Venkataraman, Rajesh; Sarkar, Saradwata; Liu, Xiabi; Nieh, Peter T; Master, Viraj V; Schuster, David M; Fei, Baowei

    2016-02-27

    This paper proposes a new semi-automatic segmentation method for the prostate on 3D transrectal ultrasound images (TRUS) by combining the region and classification information. We use a random walk algorithm to express the region information efficiently and flexibly because it can avoid segmentation leakage and shrinking bias. We further use the decision tree as the classifier to distinguish the prostate from the non-prostate tissue because of its fast speed and superior performance, especially for a binary classification problem. Our segmentation algorithm is initialized with the user roughly marking the prostate and non-prostate points on the mid-gland slice which are fitted into an ellipse for obtaining more points. Based on these fitted seed points, we run the random walk algorithm to segment the prostate on the mid-gland slice. The segmented contour and the information from the decision tree classification are combined to determine the initial seed points for the other slices. The random walk algorithm is then used to segment the prostate on the adjacent slice. We propagate the process until all slices are segmented. The segmentation method was tested in 32 3D transrectal ultrasound images. Manual segmentation by a radiologist serves as the gold standard for the validation. The experimental results show that the proposed method achieved a Dice similarity coefficient of 91.37±0.05%. The segmentation method can be applied to 3D ultrasound-guided prostate biopsy and other applications.

  16. Random walk based segmentation for the prostate on 3D transrectal ultrasound images

    NASA Astrophysics Data System (ADS)

    Ma, Ling; Guo, Rongrong; Tian, Zhiqiang; Venkataraman, Rajesh; Sarkar, Saradwata; Liu, Xiabi; Nieh, Peter T.; Master, Viraj V.; Schuster, David M.; Fei, Baowei

    2016-03-01

    This paper proposes a new semi-automatic segmentation method for the prostate on 3D transrectal ultrasound images (TRUS) by combining the region and classification information. We use a random walk algorithm to express the region information efficiently and flexibly because it can avoid segmentation leakage and shrinking bias. We further use the decision tree as the classifier to distinguish the prostate from the non-prostate tissue because of its fast speed and superior performance, especially for a binary classification problem. Our segmentation algorithm is initialized with the user roughly marking the prostate and non-prostate points on the mid-gland slice which are fitted into an ellipse for obtaining more points. Based on these fitted seed points, we run the random walk algorithm to segment the prostate on the mid-gland slice. The segmented contour and the information from the decision tree classification are combined to determine the initial seed points for the other slices. The random walk algorithm is then used to segment the prostate on the adjacent slice. We propagate the process until all slices are segmented. The segmentation method was tested in 32 3D transrectal ultrasound images. Manual segmentation by a radiologist serves as the gold standard for the validation. The experimental results show that the proposed method achieved a Dice similarity coefficient of 91.37+/-0.05%. The segmentation method can be applied to 3D ultrasound-guided prostate biopsy and other applications.

  17. Random Walk Based Segmentation for the Prostate on 3D Transrectal Ultrasound Images

    PubMed Central

    Ma, Ling; Guo, Rongrong; Tian, Zhiqiang; Venkataraman, Rajesh; Sarkar, Saradwata; Liu, Xiabi; Nieh, Peter T.; Master, Viraj V.; Schuster, David M.; Fei, Baowei

    2016-01-01

    This paper proposes a new semi-automatic segmentation method for the prostate on 3D transrectal ultrasound images (TRUS) by combining the region and classification information. We use a random walk algorithm to express the region information efficiently and flexibly because it can avoid segmentation leakage and shrinking bias. We further use the decision tree as the classifier to distinguish the prostate from the non-prostate tissue because of its fast speed and superior performance, especially for a binary classification problem. Our segmentation algorithm is initialized with the user roughly marking the prostate and non-prostate points on the mid-gland slice which are fitted into an ellipse for obtaining more points. Based on these fitted seed points, we run the random walk algorithm to segment the prostate on the mid-gland slice. The segmented contour and the information from the decision tree classification are combined to determine the initial seed points for the other slices. The random walk algorithm is then used to segment the prostate on the adjacent slice. We propagate the process until all slices are segmented. The segmentation method was tested in 32 3D transrectal ultrasound images. Manual segmentation by a radiologist serves as the gold standard for the validation. The experimental results show that the proposed method achieved a Dice similarity coefficient of 91.37±0.05%. The segmentation method can be applied to 3D ultrasound-guided prostate biopsy and other applications. PMID:27660383

  18. [Degenerative aphasia].

    PubMed

    Assal, G; Favre, C; Regli, F

    1985-01-01

    A woman had difficulties in word finding since age 59, this became a Broca's aphasia then a global aphasia. The only possible expression was written and agrammatic with many semantic errors. Calculation was preserved as well as constructional praxis. Ideomotor praxis was slightly impaired. Visual recognition and somatagnosia were normal. Neurological examination showed neither motor nor sensitive impairment. Visual fields were normal. CT scan at onset was normal. Later a slight cortical atrophy appeared predominating on the sylvian fissures, slightly more severe on the left side. Reviewing the literature the authors draw attention on the possible occurrence of an evolutive aphasia being the first evidence of a dementia. The impairment of the other cognitive functions would only appear after several years.

  19. Iris segmentation using variational level set method

    NASA Astrophysics Data System (ADS)

    Roy, Kaushik; Bhattacharya, Prabir; Suen, Ching Y.

    2011-04-01

    Continuous efforts have been made to process degraded iris images for enhancement of the iris recognition performance in unconstrained situations. Recently, many researchers have focused on developing the iris segmentation techniques, which can deal with iris images in a non-cooperative environment where the probability of acquiring unideal iris images is very high due to gaze deviation, noise, blurring, and occlusion by eyelashes, eyelids, glasses, and hair. Although there have been many iris segmentation methods, most focus primarily on the accurate detection of iris images captured in a closely controlled environment. The novelty of this research effort is that we propose to apply a variational level set-based curve evolution scheme that uses a significantly larger time step to numerically solve the evolution partial differential equation (PDE) for segmentation of an unideal iris image accurately, and thereby, speeding up the curve evolution process drastically. The iris boundary represented by the variational level set may break and merge naturally during evolution, and thus, the topological changes are handled automatically. The proposed variational model is also robust against poor localization and weak iris/sclera boundaries. In order to solve the size irregularities occurring due to arbitrary shapes of the extracted iris/pupil regions, a simple method is applied based on connection of adjacent contour points. Furthermore, to reduce the noise effect, we apply a pixel-wise adaptive 2D Wiener filter. The verification and identification performance of the proposed scheme is validated on three challenging iris image datasets, namely, the ICE 2005, the WVU Unideal, and the UBIRIS Version 1.

  20. Image segmentation by hierarchial agglomeration of polygons using ecological statistics

    DOEpatents

    Prasad, Lakshman; Swaminarayan, Sriram

    2013-04-23

    A method for rapid hierarchical image segmentation based on perceptually driven contour completion and scene statistics is disclosed. The method begins with an initial fine-scale segmentation of an image, such as obtained by perceptual completion of partial contours into polygonal regions using region-contour correspondences established by Delaunay triangulation of edge pixels as implemented in VISTA. The resulting polygons are analyzed with respect to their size and color/intensity distributions and the structural properties of their boundaries. Statistical estimates of granularity of size, similarity of color, texture, and saliency of intervening boundaries are computed and formulated into logical (Boolean) predicates. The combined satisfiability of these Boolean predicates by a pair of adjacent polygons at a given segmentation level qualifies them for merging into a larger polygon representing a coarser, larger-scale feature of the pixel image and collectively obtains the next level of polygonal segments in a hierarchy of fine-to-coarse segmentations. The iterative application of this process precipitates textured regions as polygons with highly convolved boundaries and helps distinguish them from objects which typically have more regular boundaries. The method yields a multiscale decomposition of an image into constituent features that enjoy a hierarchical relationship with features at finer and coarser scales. This provides a traversable graph structure from which feature content and context in terms of other features can be derived, aiding in automated image understanding tasks. The method disclosed is highly efficient and can be used to decompose and analyze large images.

  1. Contextual information-aided kidney segmentation in CT sequences

    NASA Astrophysics Data System (ADS)

    Zhao, Enwei; Liang, Yanmei; Fan, Hailun

    2013-03-01

    Based on the continuity of adjacent slices in a medical image sequence, a slice-based 3-D segmentation framework is constructed to extract the intact kidney by processing all slices automatically in the whole sequence. The framework includes four sections: initial segmentation, selection of the most reliable initial segmentation, location and modification of leakage. The crucial section of the proposed framework is selecting the most reliable initial segmentation image, which will be regarded as the reference image to evaluate the continuity of the following slice. Leakage location is carried out based on the contextual features, and the local iterative thresholding (LIT) is used to modify the leakage. As test examples of the framework, abdominal computed tomography (CT) images in enhanced phases are processed to segment kidney automatically. The total of 392 CT images in 7 sequences from 3 patients are selected as training images to determine the parameters in the database, and other 898 CT images in 21 sequences from 7 patients are used as test images to evaluate the effectiveness of the method. An average of three dimensional Dice similarity coefficient (3-D DSC) of 94.7% and average symmetric surface distance (ASSD) of 0.91 mm are obtained, which indicate that the intact kidney can be perfectly extracted with hardly any leakage automatically.

  2. Multiscale bi-Gaussian filter for adjacent curvilinear structures detection with application to vasculature images.

    PubMed

    Xiao, Changyan; Staring, Marius; Wang, Yaonan; Shamonin, Denis P; Stoel, Berend C

    2013-01-01

    The intensity or gray-level derivatives have been widely used in image segmentation and enhancement. Conventional derivative filters often suffer from an undesired merging of adjacent objects because of their intrinsic usage of an inappropriately broad Gaussian kernel; as a result, neighboring structures cannot be properly resolved. To avoid this problem, we propose to replace the low-level Gaussian kernel with a bi-Gaussian function, which allows independent selection of scales in the foreground and background. By selecting a narrow neighborhood for the background with regard to the foreground, the proposed method will reduce interference from adjacent objects simultaneously preserving the ability of intraregion smoothing. Our idea is inspired by a comparative analysis of existing line filters, in which several traditional methods, including the vesselness, gradient flux, and medialness models, are integrated into a uniform framework. The comparison subsequently aids in understanding the principles of different filtering kernels, which is also a contribution of this paper. Based on some axiomatic scale-space assumptions, the full representation of our bi-Gaussian kernel is deduced. The popular γ-normalization scheme for multiscale integration is extended to the bi-Gaussian operators. Finally, combined with a parameter-free shape estimation scheme, a derivative filter is developed for the typical applications of curvilinear structure detection and vasculature image enhancement. It is verified in experiments using synthetic and real data that the proposed method outperforms several conventional filters in separating closely located objects and being robust to noise.

  3. Segmentation of Unstructured Datasets

    NASA Technical Reports Server (NTRS)

    Bhat, Smitha

    1996-01-01

    Datasets generated by computer simulations and experiments in Computational Fluid Dynamics tend to be extremely large and complex. It is difficult to visualize these datasets using standard techniques like Volume Rendering and Ray Casting. Object Segmentation provides a technique to extract and quantify regions of interest within these massive datasets. This thesis explores basic algorithms to extract coherent amorphous regions from two-dimensional and three-dimensional scalar unstructured grids. The techniques are applied to datasets from Computational Fluid Dynamics and from Finite Element Analysis.

  4. SEGMENTAL CLAVICLE FRACTURE

    PubMed Central

    Grossi, Evander Azevedo

    2015-01-01

    The aim here was to present an unusual case of segmental clavicle fracture associated with ipsilateral rib fracture. Although the clavicle is very superficial, undetected cases of both types of fracture may occur, because these patients usually suffer multiple trauma. The case of a patient with a fracture of the diaphysis and lateral extremity of the clavicle is described: the patient was treated surgically and an excellent result was achieved. Similar cases in the literature are reviewed and their management is discussed. PMID:27047835

  5. Correlation of sea level falls interpreted from atoll stratigraphy with turbidites in adjacent basins

    SciTech Connect

    Lincoln, J.M. )

    1990-05-01

    Past sea levels can be derived from any atoll subsurface sediments deposited at or near sea level by determining the ages of deposition and correcting the present depths to the sediments for subsidence of the underlying edifice since the times of deposition. A sea level curve constructed by this method consists of discontinuous segments, each corresponding to a period of rising relative sea level and deposition of a discrete sedimentary package. Discontinuities in the sea level curve derived by this method correspond to relative sea level falls and stratigraphic hiatuses in the atoll subsurface. During intervals of relative sea level fall an atoll emerges to become a high limestone island. Sea level may fluctuate several times during a period of atoll emergence to become a high limestone island. Sea level may fluctuate several times during a period of atoll emergence without depositing sediments on top of the atoll. Furthermore, subaerial erosion may remove a substantial part of the depositional record of previous sea level fluctuations. For these reasons the authors must look to the adjacent basins to complement the incomplete record of sea level change recorded beneath atolls. During lowstands of sea level, faunas originally deposited near sea level on an atoll may be eroded and redeposited as turbidites in deep adjacent basins. Three such turbidites penetrated during deep-sea drilling at Sites 462 and 315 in the central Pacific correlate well with a late Tertiary sea level curve based on biostratigraphic ages and {sup 87}Sr/{sup 86}Sr chronostratigraphy for core from Enewetak Atoll in the northern Marshall Islands. Further drilling of the archipelagic aprons adjacent to atolls will improve the sea level history that may be inferred from atoll stratigraphy.

  6. Evidence Report: Risk of Cardiovascular Disease and Other Degenerative Tissue Effects from Radiation Exposure

    NASA Technical Reports Server (NTRS)

    Patel, Zarana; Huff, Janice; Saha, Janapriya; Wang, Minli; Blattnig, Steve; Wu, Honglu; Cucinotta, Francis

    2015-01-01

    Occupational radiation exposure from the space environment may result in non-cancer or non-CNS degenerative tissue diseases, such as cardiovascular disease, cataracts, and respiratory or digestive diseases. However, the magnitude of influence and mechanisms of action of radiation leading to these diseases are not well characterized. Radiation and synergistic effects of radiation cause DNA damage, persistent oxidative stress, chronic inflammation, and accelerated tissue aging and degeneration, which may lead to acute or chronic disease of susceptible organ tissues. In particular, cardiovascular pathologies such as atherosclerosis are of major concern following gamma-ray exposure. This provides evidence for possible degenerative tissue effects following exposures to ionizing radiation in the form of the GCR or SPEs expected during long-duration spaceflight. However, the existence of low dose thresholds and dose-rate and radiation quality effects, as well as mechanisms and major risk pathways, are not well-characterized. Degenerative disease risks are difficult to assess because multiple factors, including radiation, are believed to play a role in the etiology of the diseases. As additional evidence is pointing to lower, space-relevant thresholds for these degenerative effects, particularly for cardiovascular disease, additional research with cell and animal studies is required to quantify the magnitude of this risk, understand mechanisms, and determine if additional protection strategies are required.The NASA PEL (Permissive Exposure Limit)s for cataract and cardiovascular risks are based on existing human epidemiology data. Although animal and clinical astronaut data show a significant increase in cataracts following exposure and a reassessment of atomic bomb (A-bomb) data suggests an increase in cardiovascular disease from radiation exposure, additional research is required to fully understand and quantify these adverse outcomes at lower doses (less than 0.5 gray

  7. Robust nonparametric segmentation of infarct lesion from diffusion-weighted MR images.

    PubMed

    Hevia-Montiel, Nidiyare; Jiménez-Alaniz, Juan Ramón; Medina-Bañuelos, Verónica; Yáñez-Suárez, Oscar; Rosso, Charlotte; Samson, Yves; Baillet, Sylvain

    2007-01-01

    Magnetic Resonance Imaging (MRI) is increasingly used for the diagnosis and monitoring of neurological disorders. In particular Diffusion-Weighted MRI (DWI) is highly sensitive in detecting early cerebral ischemic changes in acute stroke. Cerebral infarction lesion segmentation from DWI is accomplished in this work by applying nonparametric density estimation. The quality of the class boundaries is improved by including an edge confidence map, that is the confidence of truly being in the presence of a border between adjacent regions. The adjacency graph, that is constructed with the label regions, is analyzed and pruned to merge adjacent regions. The method was applied to real images, keeping all parameters constant throughout the process for each data set. The combination of region segmentation and edge detection proved to be a robust automatic technique of segmentation from DWI images of cerebral infarction regions in acute ischemic stroke. In a comparison with the reference infarct lesions segmentation, the automatic segmentation presented a significant correlation (r=0.935), and an average Tanimoto index of 0.538.

  8. Adenovirus-mediated GDF-5 promotes the extracellular matrix expression in degenerative nucleus pulposus cells*

    PubMed Central

    Luo, Xu-wei; Liu, Kang; Chen, Zhu; Zhao, Ming; Han, Xiao-wei; Bai, Yi-guang; Feng, Gang

    2016-01-01

    Objective: To construct a recombinant adenovirus vector-carrying human growth and differentiation factor-5 (GDF-5) gene, investigate the biological effects of adenovirus-mediated GDF-5 (Ad-GDF-5) on extracellular matrix (ECM) expression in human degenerative disc nucleus pulposus (NP) cells, and explore a candidate gene therapy method for intervertebral disc degeneration (IDD). Methods: Human NP cells of a degenerative disc were isolated, cultured, and infected with Ad-GDF-5 using the AdEasy-1 adenovirus vector system. On Days 3, 7, 14, and 21, the contents of the sulfated glycosaminoglycan (sGAG), deoxyribonucleic acid (DNA) and hydroxyproline (Hyp), synthesis of proteoglycan and collagen II, gene expression of collagen II and aggrecan, and NP cell proliferation were assessed. Results: The adenovirus was an effective vehicle for gene delivery with prolonged expression of GDF-5. Biochemical analysis revealed increased sGAG and Hyp contents in human NP cells infected by Ad-GDF-5 whereas there was no conspicuous change in basal medium (BM) or Ad-green fluorescent protein (GFP) groups. Only cells in the Ad-GDF-5 group promoted the production of ECM, as demonstrated by the secretion of proteoglycan and up-regulation of collagen II and aggrecan at both protein and mRNA levels. The NP cell proliferation was significantly promoted. Conclusions: The data suggest that Ad-GDF-5 gene therapy is a potential treatment for IDD, which restores the functions of degenerative intervertebral disc through enhancing the ECM production of human NP cells. PMID:26739524

  9. Spinal Deformity in Aged Zebrafish Is Accompanied by Degenerative Changes to Their Vertebrae that Resemble Osteoarthritis

    PubMed Central

    Hayes, Anthony J.; Reynolds, Scott; Nowell, Mari A.; Meakin, Lee B.; Habicher, Judith; Ledin, Johan; Bashford, Andrew; Caterson, Bruce; Hammond, Chrissy L.

    2013-01-01

    Age-related degenerative changes within the vertebral column are a significant cause of morbidity with considerable socio-economic impact worldwide. An improved understanding of these changes through the development of experimental models may lead to improvements in existing clinical treatment options. The zebrafish is a well-established model for the study of skeletogenesis with significant potential in gerontological research. With advancing age, zebrafish frequently develop gross deformities of their vertebral column, previously ascribed to reduced trunk muscle tone. In this study, we assess degenerative changes specifically within the bone and cartilage of the vertebral column of zebrafish at 1, 2 and 3-years of age. We show increased frequency and severity of spinal deformities/curvatures with age. Underlying the most severe phenotypes are partial or complete vertebral dislocations and focal thickening of the vertebral bone at the joint margins. MicroCT examination demonstrates small defects, fractures and morphological evidence suggestive of bone erosion and remodeling (i.e. osteophytes) within the vertebrae during aging, but no significant change in bone density. Light and electron microscopic examination reveal striking age-related changes in cell morphology, suggestive of chondroptosis, and tissue remodelling of the vertebral cartilage, particularly within the pericellular micro-environment. Glycosaminoglycan analysis of the vertebral column by HPLC demonstrates a consistent, age-related increase in the yield of total chondroitin sulfate disaccharide, but no change in sulfation pattern, supported by immunohistochemical analysis. Immunohistochemistry strongly identifies all three chondroitin/dermatan sulphate isoforms (C-0-S, C-4-S/DS and C-6-S) within the vertebral cartilage, particularly within the pericellular micro-environment. In contrast, keratan sulfate immunolocalises specifically with the notochordal tissue of the intervertebral disc, and its

  10. Lumbar Disc Degenerative Disease: Disc Degeneration Symptoms and Magnetic Resonance Image Findings

    PubMed Central

    Saleem, Shafaq; Rehmani, Muhammad Asim Khan; Raees, Aisha; Alvi, Arsalan Ahmad; Ashraf, Junaid

    2013-01-01

    Study Design Cross sectional and observational. Purpose To evaluate the different aspects of lumbar disc degenerative disc disease and relate them with magnetic resonance image (MRI) findings and symptoms. Overview of Literature Lumbar disc degenerative disease has now been proven as the most common cause of low back pain throughout the world. It may present as disc herniation, lumbar spinal stenosis, facet joint arthropathy or any combination. Presenting symptoms of lumbar disc degeneration are lower back pain and sciatica which may be aggravated by standing, walking, bending, straining and coughing. Methods This study was conducted from January 2012 to June 2012. Study was conducted on the diagnosed patients of lumbar disc degeneration. Diagnostic criteria were based upon abnormal findings in MRI. Patients with prior back surgery, spine fractures, sacroiliac arthritis, metabolic bone disease, spinal infection, rheumatoid arthritis, active malignancy, and pregnancy were excluded. Results During the targeted months, 163 patients of lumbar disc degeneration with mean age of 43.92±11.76 years, came into Neurosurgery department. Disc degeneration was most commonly present at the level of L4/L5 105 (64.4%).Commonest types of disc degeneration were disc herniation 109 (66.9%) and lumbar spinal stenosis 37 (22.7%). Spondylolisthesis was commonly present at L5/S1 10 (6.1%) and associated mostly with lumbar spinal stenosis 7 (18.9%). Conclusions Results reported the frequent occurrence of lumbar disc degenerative disease in advance age. Research efforts should endeavor to reduce risk factors and improve the quality of life. PMID:24353850

  11. Spinal deformity in aged zebrafish is accompanied by degenerative changes to their vertebrae that resemble osteoarthritis.

    PubMed

    Hayes, Anthony J; Reynolds, Scott; Nowell, Mari A; Meakin, Lee B; Habicher, Judith; Ledin, Johan; Bashford, Andrew; Caterson, Bruce; Hammond, Chrissy L

    2013-01-01

    Age-related degenerative changes within the vertebral column are a significant cause of morbidity with considerable socio-economic impact worldwide. An improved understanding of these changes through the development of experimental models may lead to improvements in existing clinical treatment options. The zebrafish is a well-established model for the study of skeletogenesis with significant potential in gerontological research. With advancing age, zebrafish frequently develop gross deformities of their vertebral column, previously ascribed to reduced trunk muscle tone. In this study, we assess degenerative changes specifically within the bone and cartilage of the vertebral column of zebrafish at 1, 2 and 3-years of age. We show increased frequency and severity of spinal deformities/curvatures with age. Underlying the most severe phenotypes are partial or complete vertebral dislocations and focal thickening of the vertebral bone at the joint margins. MicroCT examination demonstrates small defects, fractures and morphological evidence suggestive of bone erosion and remodeling (i.e. osteophytes) within the vertebrae during aging, but no significant change in bone density. Light and electron microscopic examination reveal striking age-related changes in cell morphology, suggestive of chondroptosis, and tissue remodelling of the vertebral cartilage, particularly within the pericellular micro-environment. Glycosaminoglycan analysis of the vertebral column by HPLC demonstrates a consistent, age-related increase in the yield of total chondroitin sulfate disaccharide, but no change in sulfation pattern, supported by immunohistochemical analysis. Immunohistochemistry strongly identifies all three chondroitin/dermatan sulphate isoforms (C-0-S, C-4-S/DS and C-6-S) within the vertebral cartilage, particularly within the pericellular micro-environment. In contrast, keratan sulfate immunolocalises specifically with the notochordal tissue of the intervertebral disc, and its

  12. Teaching early braille literacy skills within a stimulus equivalence paradigm to children with degenerative visual impairments.

    PubMed

    Toussaint, Karen A; Tiger, Jeffrey H

    2010-01-01

    Despite the need for braille literacy, there has been little attempt to systematically evaluate braille-instruction programs. The current study evaluated an instructive procedure for teaching early braille-reading skills with 4 school-aged children with degenerative visual impairments. Following a series of pretests, braille instruction involved providing a sample braille letter and teaching the selection of the corresponding printed letter from a comparison array. Concomitant with increases in the accuracy of this skill, we assessed and captured the formation of equivalence classes through tests of symmetry and transitivity among the printed letters, the corresponding braille letters, and their spoken names.

  13. [Locomotive syndrome and frailty. Locomotive syndrome due to the underlying disease of degenerative arthritis].

    PubMed

    Chosa, Etsuo

    2012-04-01

    Japan became a superaging society. We have been putting a new focus on locomotive syndrome and frailty. The prevention and treatment of locomotive syndromes, such as osteoarthritis, degenerative spondylosis, lumbar canal stenosis, osteoporosis, upper extremity diseases, rheumatoid arthritis, and many other disorders of the locomotive organs are important. Because, the locomotive syndrome results in deterioration of the exercise function and loss of mental and physical health. The aim of locomotive syndrome exercises are: to reduce pain, to restore and improve joint function. We need to take a comprehensive approach to locomotive syndrome, including lifestyle modification, muscle exercise, stretching and therapeutic exercise.

  14. Segmental arterial mediolysis.

    PubMed

    Pillai, Anil Kumar; Iqbal, Shams I; Liu, Raymond W; Rachamreddy, Niranjan; Kalva, Sanjeeva P

    2014-06-01

    Segmental arterial mediolysis (SAM) is an uncommon, nonatherosclerotic, noninflammatory, large- to medium-sized arteriopathy first described in 1976. It is characterized histologically by vacuolization and lysis of the outer arterial media leading to dissecting aneurysms and vessel rupture presenting clinically with self-limiting abdominal pain or catastrophic hemorrhages in the abdomen. Patients of all ages are affected with a greater incidence at the fifth and sixth decades. There is a slight male predominance. Imaging findings overlap with inflammatory vasculitis, collagen vascular disease, and fibromuscular dysplasia. The presence of segmental dissections involving the celiac, mesenteric, and/or renal arteries is the key distinguishing features of SAM. Inflammatory markers, genetic tests for collagen vascular disorders, and hypercoagulable studies are negative. Anti-inflammatory agents and immunosuppressants are not effective. A mortality rate of 50 % has been attributed to the acute presentation with aneurysmal rupture necessitating urgent surgical or endovascular treatments; in the absence of the acute presentation, SAM is a self-limiting disease and is treated conservatively. There are no established guidelines on medical therapy, although optimal control of blood pressure is considered the main cornerstone of medical therapy. The long-term prognosis is not known.

  15. Segmented Target Design

    NASA Astrophysics Data System (ADS)

    Merhi, Abdul Rahman; Frank, Nathan; Gueye, Paul; Thoennessen, Michael; MoNA Collaboration

    2013-10-01

    A proposed segmented target would improve decay energy measurements of neutron-unbound nuclei. Experiments like this have been performed at the National Superconducting Cyclotron Laboratory (NSCL) located at Michigan State University. Many different nuclei are produced in such experiments, some of which immediately decay into a charged particle and neutron. The charged particles are bent by a large magnet and measured by a suite of charged particle detectors. The neutrons are measured by the Modular Neutron Array (MoNA) and Large Multi-Institutional Scintillation Array (LISA). With the current target setup, a nucleus in a neutron-unbound state is produced with a radioactive beam impinged upon a beryllium target. The resolution of these measurements is very dependent on the target thickness since the nuclear interaction point is unknown. In a segmented target using alternating layers of silicon detectors and Be-targets, the Be-target in which the nuclear reaction takes place would be determined. Thus the experimental resolution would improve. This poster will describe the improvement over the current target along with the status of the design. Work supported by Augustana College and the National Science Foundation grant #0969173.

  16. Sea-floor drainage features of Cascadia Basin and the adjacent continental slope, northeast Pacific Ocean

    USGS Publications Warehouse

    Hampton, M.A.; Karl, Herman A.; Kenyon, Neil H.

    1989-01-01

    Sea-floor drainage features of Cascadia Basin and the adjacent continental slope include canyons, primary fan valleys, deep-sea valleys, and remnant valley segments. Long-range sidescan sonographs and associated seismic-reflection profiles indicate that the canyons may originate along a mid-slope escarpment and grow upslope by mass wasting and downslope by valley erosion or aggradation. Most canyons are partly filled with sediment, and Quillayute Canyon is almost completely filled. Under normal growth conditions, the larger canyons connect with primary fan valleys or deep-sea valleys in Cascadia Basin, but development of accretionary ridges blocks or re-routes most canyons, forcing abandonment of the associated valleys in the basin. Astoria Fan has a primary fan valley that connects with Astoria Canyon at the fan apex. The fan valley is bordered by parallel levees on the upper fan but becomes obscure on the lower fan, where a few valley segments appear on the sonographs. Apparently, Nitinat Fan does not presently have a primary fan valley; none of the numerous valleys on the fan connect with a canyon. The Willapa-Cascadia-Vancouver-Juan de Fuca deep-sea valley system bypasses the submarine fans and includes deeply incised valleys to broad shallow swales, as well as within-valley terraces and hanging-valley confluences. ?? 1989.

  17. Trunk segment numbers and sequential segmentation in myriapods.

    PubMed

    Fusco, Giuseppe

    2005-01-01

    Sequential segmentation from a posterior "proliferative zone" is considered to be the primitive mechanism of segmentation in arthropods. Several studies of embryonic and post-embryonic development and gene expression suggest that this occurs in all major arthropod taxa. Sequential segmentation is often associated with the idea of posterior production of body units that accumulate along the main body axis. However, the precise mechanism of sequential segmentation has not been identified yet, and, while searching for the genetic circuitry able to generate a first periodic pattern in the embryo, we can at least outline the distinctive role in segmentation of a proliferative zone. A perusal of myriapod segmentation patterns suggests that these patterns result from multi-layered developmental processes, where gene expression and epigenetic mechanisms interact in a nonstrictly hierarchical way. The posterior zone is possibly a zone of periodic signal production, but, in general, the resulting segmental pattern is not completely attributable to the activity of the signal generator. In this sense, a posterior proliferative zone would be more a "segmental organizer" than a "segment generator."

  18. CALM: cascading system with leaking detection mechanism for medical image segmentation

    NASA Astrophysics Data System (ADS)

    Liu, Jiang; Lim, Joo Hwee; Li, Huiqi

    2008-03-01

    Medical image segmentation is a challenging process due to possible image over-segmentation and under-segmentation (leaking). The CALM medical image segmentation system is constructed with an innovative scheme that cascades threshold level-set and region-growing segmentation algorithms using Union and Intersection set operators. These set operators help to balance the over-segmentation rate and under-segmentation rate of the system respectively. While adjusting the curvature scalar parameter in the threshold level-set algorithm, we observe that the abrupt change in the size of the segmented areas coincides with the occurrences of possible leaking. Instead of randomly choose a value or use the system default curvature scalar values, this observation prompts us to use the following formula in CALM to automatically decide the optimal curvature values γ to prevent the occurrence of leaking : δ2S/δγ2 >= M, where S is the size of the segmented area and M is a large positive number. Motivated for potential applications in organ transplant and analysis, the CALM system is tested on the segmentation of the kidney regions from the Magnetic Resonance images taken from the National University Hospital of Singapore. Due to the nature of MR imaging, low-contrast, weak edges and overlapping regions of adjacent organs at kidney boundaries are frequently seen in the datasets and hence kidney segmentation is prone to leaking. The kidney segmentation accuracy rate achieved by CALM is 22% better compared with those achieved by the component algorithms or the system without leaking detection mechanism. CALM is easy-to-implement and can be applied to many applications besides kidney segmentation.

  19. Laplacian versus adjacency matrix in quantum walk search

    NASA Astrophysics Data System (ADS)

    Wong, Thomas G.; Tarrataca, Luís; Nahimov, Nikolay

    2016-10-01

    A quantum particle evolving by Schrödinger's equation contains, from the kinetic energy of the particle, a term in its Hamiltonian proportional to Laplace's operator. In discrete space, this is replaced by the discrete or graph Laplacian, which gives rise to a continuous-time quantum walk. Besides this natural definition, some quantum walk algorithms instead use the adjacency matrix to effect the walk. While this is equivalent to the Laplacian for regular graphs, it is different for non-regular graphs and is thus an inequivalent quantum walk. We algorithmically explore this distinction by analyzing search on the complete bipartite graph with multiple marked vertices, using both the Laplacian and adjacency matrix. The two walks differ qualitatively and quantitatively in their required jumping rate, runtime, sampling of marked vertices, and in what constitutes a natural initial state. Thus the choice of the Laplacian or adjacency matrix to effect the walk has important algorithmic consequences.

  20. Multiple-Segment Climbing Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James; May, Edward; Eklund, Wayne

    1994-01-01

    Multiple-segment climbing robots developed to perform such tasks as inspection, sandblasting, welding, and painting on towers and other structures. Look and move like caterpillars. Video camera mounted on one of segments rotated to desired viewing angle. Used in remote inspection of structure, to view motion of robot and/or provides video feedback for control of motion, and/or to guide operation of head mounted on foremost segment with motorized actuators.

  1. Intervertebral disc regeneration: from the degenerative cascade to molecular therapy and tissue engineering.

    PubMed

    Vadalà, Gianluca; Russo, Fabrizio; Di Martino, Alberto; Denaro, Vincenzo

    2015-06-01

    Low back pain is one of the major health problems in industrialized countries, as a leading source of disability in the working population. Intervertebral disc degeneration has been identified as its main cause, being a progressive process mainly characterized by alteration of extracellular matrix composition and water content. Many factors are involved in the degenerative cascade, such as anabolism/catabolism imbalance, reduction of nutrition supply and progressive cell loss. Currently available treatments are symptomatic, and surgical procedures consisting of disc removal are often necessary. Recent advances in our understanding of intervertebral disc biology led to an increased interest in the development of novel biological treatments aimed at disc regeneration. Growth factors, gene therapy, stem cell transplantation and biomaterials-based tissue engineering might support intervertebral disc regeneration by overcoming the limitation of the self-renewal mechanism. The aim of this paper is to overview the literature discussing the current status of our knowledge from the degenerative cascade of the intervertebral disc to the latest molecular, cell-based therapies and tissue-engineering strategies for disc regeneration.

  2. IL-1β induces apoptosis and autophagy via mitochondria pathway in human degenerative nucleus pulposus cells

    PubMed Central

    Shen, Jieliang; Xu, Shengxi; Zhou, Hao; Liu, Huzhe; Jiang, Wei; Hao, Jie; Hu, Zhenming

    2017-01-01

    IL-1β has been reported highly expressed in degenerative intervertebral disc, and our previous study indicated IL-1β facilitates apoptosis of human degenerative nucleus pulposus (NP) cell. However, the underlying molecular mechanism remains unclear. We here demonstrate that IL-1β played a significantly pro-apoptotic effect under serum deprivation. IL-1β decreased Bcl-2/Bax ratio and enhanced cytochrome C released from mitochondria to cytosol, which proved mitochondria-meidated apoptosis was induced. Subsequently, mitochondria damage was detected under IL-1β stimualtion. In addition, IL-1β-mediated injuried mitochondria contributes to activate autophagy. However, pretreatment with the autophagy inhibitor 3-methyladenine showed the potential in further elevating the apoptosis rate induced by IL-1β in NP cells. Our results indicated that the mitochondrial pathway was involved in IL-1β-induced apoptosis of NP cells. Meanwhile, the damaged mitochondria-induced autophagy played a protective role against apoptosis, suggesting a postive feedback mechanism under inflammatory stress. PMID:28120948

  3. Quantitative ultrasound imaging detects degenerative changes in articular cartilage surface and subchondral bone

    NASA Astrophysics Data System (ADS)

    Saarakkala, Simo; Laasanen, Mikko S.; Jurvelin, Jukka S.; Töyräs, Juha

    2006-10-01

    Previous studies have suggested that quantitative ultrasound imaging could sensitively diagnose degeneration of the articular surface and changes in the subchondral bone during the development of osteoarthrosis (OA). We have recently introduced a new parameter, ultrasound roughness index (URI), for the quantification of cartilage surface roughness, and successfully tested it with normal and experimentally degraded articular surfaces. In this in vitro study, the applicability of URI was tested in bovine cartilage samples with spontaneously developed tissue degeneration. Simultaneously, we studied the sensitivity of quantitative ultrasound imaging to detect degenerative changes in the cartilage-bone interface. For reference, histological degenerative grade of the cartilage samples was determined. Mechanical reference measurements were also conducted. Cartilage surface roughness (URI) was significantly (p < 0.05) higher in histologically degenerated samples with inferior mechanical properties. Ultrasound reflection at the cartilage-bone interface was also significantly (p < 0.05) increased in degenerated samples. Furthermore, it was quantitatively confirmed that ultrasound attenuation in the overlying cartilage significantly affects the measured ultrasound reflection values from the cartilage-bone interface. To conclude, the combined ultrasound measurement of the cartilage surface roughness and ultrasound reflection at the cartilage-bone interface complement each other, and may together enable more sensitive and quantitative diagnosis of early OA or follow up after surgical cartilage repair.

  4. Novel Strategies for the Improvement of Stem Cells' Transplantation in Degenerative Retinal Diseases

    PubMed Central

    Nicoară, Simona Delia; Șușman, Sergiu; Tudoran, Oana; Bărbos, Otilia; Cherecheș, Gabriela; Aștilean, Simion; Potara, Monica; Sorițău, Olga

    2016-01-01

    Currently, there is no cure for the permanent vision loss caused by degenerative retinal diseases. One of the novel therapeutic strategies aims at the development of stem cells (SCs) based neuroprotective and regenerative medicine. The main sources of SCs for the treatment of retinal diseases are the embryo, the bone marrow, the region of neuronal genesis, and the eye. The success of transplantation depends on the origin of cells, the route of administration, the local microenvironment, and the proper combinative formula of growth factors. The feasibility of SCs based therapies for degenerative retinal diseases was proved in the preclinical setting. However, their translation into the clinical realm is limited by various factors: the immunogenicity of the cells, the stability of the cell phenotype, the predilection of SCs to form tumors in situ, the abnormality of the microenvironment, and the association of a synaptic rewiring. To improve SCs based therapies, nanotechnology offers a smart delivery system for biomolecules, such as growth factors for SCs implantation and differentiation into retinal progenitors. This review explores the main advances in the field of retinal transplantology and applications of nanotechnology in the treatment of retinal diseases, discusses the challenges, and suggests new therapeutic approaches in retinal transplantation. PMID:27293444

  5. Nucleoplasty for treating lumbar disk degenerative low back pain: an outcome prediction analysis

    PubMed Central

    Liliang, Po-Chou; Lu, Kang; Liang, Cheng-Loong; Chen, Ya-Wen; Tsai, Yu-Duan; Tu, Yuan-Kun

    2016-01-01

    Purpose Nucleoplasty is a minimally invasive technique that is considered efficacious in alleviating lumbar disk degenerative low back pain (LBP). The efficacy of nucleoplasty and identified variables that can predict pain relief for nucleoplasty was reported. Patients and methods Between December 2013 and November 2015, 47 nucleoplasty procedures on 47 lumbar disks in 31 consecutive patients were performed. The outcome was evaluated using a visual analog scale (VAS) score. Improvements of ≥50% in VAS scores were considered substantial pain relief. The variables associated with pain relief after nucleoplasty included: 1) age; 2) sex; 3) body mass index; 4) hyperintensity zone at the rear of the disk; 5) hypointensity of the disk; 6) Modic changes of the end plates; 7) spinal instability pain; and 8) discography results. Results Twenty-one patients (67.7%) experienced substantial pain relief. The most common side effects following nucleoplasty were soreness at the needle puncture site (64.5%), numbness in the lower leg (12.9%), and increased intensity of back pain (9.7%). All side effects were transient. Multivariate analysis revealed that the discography results were the most critical predictor for substantial pain relief of nucleoplasty (P=0.03). The sensitivity and specificity of discography were 92.8% and 62.5%, respectively. Conclusion Discography results could improve the success rate of nucleoplasty in the treatment of disk degenerative LBP. PMID:27826211

  6. Perspectives of Stem Cell-Based Therapy for Age-Related Retinal Degenerative Diseases.

    PubMed

    Holan, Vladimir; Hermankova, Barbora; Kossl, Jan

    2017-03-17

    Retinal degenerative diseases, which include age-related macular degeneration, retinitis pigmentosa, diabetic retinopathy and glaucoma, mostly affect the elderly population, and are the most common cause of decreased quality of vision or even blindness. So far, there is no satisfactory treatment protocol to prevent, stop or cure these disorders. A great hope and promise for patients suffering from retinal diseases is represented by stem cell-based therapy which could replace diseased or missing retinal cells, and support regeneration. In this respect, mesenchymal stem cells (MSCs) which can be obtained from the particular patient, and used as autologous cells, have turned out to be a promising stem cell type for treatment. Here we show that MSCs can differentiate into cells expressing markers of retinal cells, inhibit production of proinflammatory cytokines by retinal tissue and produce a number of growth and neuroprotective factors for retinal regeneration. All of these properties make MSCs a prospective cell type for cell-based therapy of age-related retinal degenerative diseases.

  7. [Pharmacologic evaluation of the feasibility of cartilage therapy in degenerative joint diseases (arthroses)].

    PubMed

    Kalbhen, D A

    1983-01-01

    Due to their pharmacological properties most antiphlogistic/antirheumatic drugs are successfully used for treatment of inflammatory rheumatic diseases, but they are not able to counteract cartilage degeneration in osteoarthrosis. For specific therapy of osteoarthrosis only those drugs are suitable, which are able to inhibit enzymatic breakdown of articular cartilage, stimulate anabolic processes in cartilage, and to enhance the supply of nutritional and energy substrates for the cartilage cells. In this respect drugs such as Arteparon, Rumalon, Dona 200-S, Glyvenol or Pentosan polysulfate are of interest. A great number of pharmacological experiments have shown, that certain chondroprotective agents exert pronounced anti-degenerative effects, which can be quantitatively demonstrated in laboratory animals within 3 to 4 months by macroscopical, radiological and histological methods. Additional biochemical and in-vitro studies have elucidated some interesting chondro-protective, chondro-stimulatory or chondro-nutritive properties of certain drugs. In agreement with our experimental results clinical experiences have proved the efficacy of chondro-protective agents. Due to the bradytrophia of human articular cartilage a chondro-protective therapy may be only effective in long-term applications, resulting in a significant reduction of the intensity and progression of the degenerative joint destruction.

  8. Association of COL2A1 Gene Polymorphism with Degenerative Lumbar Scoliosis

    PubMed Central

    Hwang, Dae Woo; Lee, Sang Hoon; Kim, Jung Youn; Kim, Dong Hwan

    2014-01-01

    Background Degenerative lumbar scoliosis (DLS) progresses with aging after 50-60 years, and the genetic association of DLS remains largely unclear. In this study, the genetic association between collagen type II alpha 1 (COL2A1) gene and DLS was investigated. Methods COL2A1 gene polymorphism was investigated in DLS subjects compared to healthy controls to investigate the possibility of its association with COL2A1 gene. Based on a single nucleotide polymorphism (SNP) database, SNP (rs2276454) in COL2A1 were selected and genotyped using direct sequencing in 51 patients with DLS and 235 healthy controls. The SNP effects were analyzed using three models of codominant, dominant, and recessive. Logistic regression models were calculated for odds ratios (ORs) with 95% confidence intervals (CIs) and corresponding p-values, controlling age and gender as co-variables. Results SNP (rs2276454) in COL2A1 was significantly associated with the degenerative lumbar scoliosis in the codominant (OR, 1.90; 95% CI, 1.17 to 3.10; p = 0.008) and dominant models (OR, 3.58; 95% CI, 1.59 to 9.29; p = 0.001). Conclusions The results suggest that COL2A1 is associated with the risk of DLS in Korean population. PMID:25436060

  9. Degenerative Tissue Responses to Space-like Radiation Doses in a Rodent Model of Simulated Microgravity.

    PubMed

    Chowdhury, Parimal; Akel, Nisreen; Jamshidi-Parsian, Azemat; Gaddy, Dana; Griffin, Robert J; Yadlapalli, Jai Shankar K; Dobretsov, Maxim

    2016-01-01

    This study examines acute and degenerative tissue responses to space-like radiation doses in a rodent model of simulated microgravity. We have studied four groups of rats, control (CON), irradiated (IR), irradiated and hindlimb suspended (IR-HLS), and suspended (HLS) that were maintained for two weeks. IR and IR+HLS groups were exposed to five sessions of X-ray irradiation (1.2 Gy each, at 3-4 days intervals). Body weights, soleus muscle weights, and hindlimb bone mineral density (BMD) were measured. Results show that compared to CON animals, IR, HLS, and IR+HLS group reduced the body weight gain significantly. IR-associated growth retardation appeared to be closely linked to acute and transient post-IR 'anorexia' (a decrease in food intake). HLS but not IR induced major changes in the musculoskeletal system, consisting in decreases in soleus muscle mass and bone mineral density of distal femur and proximal tibia. Additional dosimetric studies showed that the effect of IR on weight is detectable at 0.3 Gy X-ray doses, while no threshold dose for the IR-produced decrease in food intake could be observed. This study suggests that space flight-associated anorexia and musculoskeletal degenerative changes may be driven by different, radiation- and microgravity-associated (respectively) mechanisms.

  10. Nd:YAG laser in experimentally induced chronic degenerative osteoarthritis in broiler chickens: pilot study

    NASA Astrophysics Data System (ADS)

    Fortuna, Damiano; Rossi, Giacomo; Bilotta, Teresa W.; Zati, Allesandro; Cardillo, Ilaria; Venturini, Antonio; Pinna, Stefania; Serra, Christian; Masotti, Leonardo

    2002-10-01

    The Low Level Laser Therapy (LLLT) has been widely tested in arthritis disorders, but there is still some disagreement in the results, therefore in this study we have investigated High Intensity Laser Therapy (HILT). The degenerative arthritis was induced in 18 chickens by intra-articular inoculation of Freund's complete adjuvant. Clinical studies were carried out (weight increase and grades of lameness) as well as morphological (macroscopic and histological) tests and seroassay (C Reactive Protein). The Nd:YAG pulsed wave was employed. The serologic data revealed the anti-inflammatory effect on the laser, with a highly significant difference between those treated and the control group. No lesion on the skin, i.e. burn, or in depth has been observed in the Treated group. Heavyline of broiler chickens in growing age has been revealed a good animal model of O.A.. The Nd:YAG Pulsed Wave it is safe on these structures. The anti-inflammatory effect of the HILT it seems to contrast the destructive degenerative process.

  11. Dystrophin and utrophin "double knockout" dystrophic mice exhibit a spectrum of degenerative musculoskeletal abnormalities.

    PubMed

    Isaac, Christian; Wright, Adam; Usas, Arvydas; Li, Hongshuai; Tang, Ying; Mu, Xiaodong; Greco, Nicholas; Dong, Qing; Vo, Nam; Kang, James; Wang, Bing; Huard, Johnny

    2013-03-01

    Duchenne muscular dystrophy (DMD) is a degenerative muscle disorder characterized by the lack of dystrophin expression at the sarcolemma of muscle fibers. In addition, DMD patients acquire osteopenia, fragility fractures, and scoliosis indicating that a deficiency in skeletal homeostasis coexists but little is known about the effects of DMD on bone and other connective tissues within the musculoskeletal system. Recent evidence has emerged implicating adult stem cell dysfunction in DMD myopathogenesis. Given the common mesenchymal origin of muscle and bone, we sought to investigate bone and other musculoskeletal tissues in a DMD mouse model. Here, we report that dystrophin-utrophin double knockout (dko) mice exhibit a spectrum of degenerative changes, outside skeletal muscle, in bone, articular cartilage, and intervertebral discs, in addition to reduced lifespan, muscle degeneration, spinal deformity, and cardiomyopathy previously reported. We also report these mice to have a reduced capacity for bone healing and exhibit spontaneous heterotopic ossification in the hind limb muscles. Therefore, we propose the dko mouse as a model for premature musculoskeletal aging and posit that a similar phenomenon may occur in patients with DMD.

  12. Modeling fires in adjacent ship compartments with computational fluid dynamics

    SciTech Connect

    Wix, S.D.; Cole, J.K.; Koski, J.A.

    1998-05-10

    This paper presents an analysis of the thermal effects on radioactive (RAM) transportation packages with a fire in an adjacent compartment. An assumption for this analysis is that the adjacent hold fire is some sort of engine room fire. Computational fluid dynamics (CFD) analysis tools were used to perform the analysis in order to include convective heat transfer effects. The analysis results were compared to experimental data gathered in a series of tests on tile US Coast Guard ship Mayo Lykes located at Mobile, Alabama.

  13. Probabilistic retinal vessel segmentation

    NASA Astrophysics Data System (ADS)

    Wu, Chang-Hua; Agam, Gady

    2007-03-01

    Optic fundus assessment is widely used for diagnosing vascular and non-vascular pathology. Inspection of the retinal vasculature may reveal hypertension, diabetes, arteriosclerosis, cardiovascular disease and stroke. Due to various imaging conditions retinal images may be degraded. Consequently, the enhancement of such images and vessels in them is an important task with direct clinical applications. We propose a novel technique for vessel enhancement in retinal images that is capable of enhancing vessel junctions in addition to linear vessel segments. This is an extension of vessel filters we have previously developed for vessel enhancement in thoracic CT scans. The proposed approach is based on probabilistic models which can discern vessels and junctions. Evaluation shows the proposed filter is better than several known techniques and is comparable to the state of the art when evaluated on a standard dataset. A ridge-based vessel tracking process is applied on the enhanced image to demonstrate the effectiveness of the enhancement filter.

  14. Segmented heat exchanger

    DOEpatents

    Baldwin, Darryl Dean; Willi, Martin Leo; Fiveland, Scott Byron; Timmons, Kristine Ann

    2010-12-14

    A segmented heat exchanger system for transferring heat energy from an exhaust fluid to a working fluid. The heat exchanger system may include a first heat exchanger for receiving incoming working fluid and the exhaust fluid. The working fluid and exhaust fluid may travel through at least a portion of the first heat exchanger in a parallel flow configuration. In addition, the heat exchanger system may include a second heat exchanger for receiving working fluid from the first heat exchanger and exhaust fluid from a third heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the second heat exchanger in a counter flow configuration. Furthermore, the heat exchanger system may include a third heat exchanger for receiving working fluid from the second heat exchanger and exhaust fluid from the first heat exchanger. The working fluid and exhaust fluid may travel through at least a portion of the third heat exchanger in a parallel flow configuration.

  15. Partially segmented deformable mirror

    DOEpatents

    Bliss, Erlan S.; Smith, James R.; Salmon, J. Thaddeus; Monjes, Julio A.

    1991-01-01

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp.

  16. Partially segmented deformable mirror

    DOEpatents

    Bliss, E.S.; Smith, J.R.; Salmon, J.T.; Monjes, J.A.

    1991-05-21

    A partially segmented deformable mirror is formed with a mirror plate having a smooth and continuous front surface and a plurality of actuators to its back surface. The back surface is divided into triangular areas which are mutually separated by grooves. The grooves are deep enough to make the plate deformable and the actuators for displacing the mirror plate in the direction normal to its surface are inserted in the grooves at the vertices of the triangular areas. Each actuator includes a transducer supported by a receptacle with outer shells having outer surfaces. The vertices have inner walls which are approximately perpendicular to the mirror surface and make planar contacts with the outer surfaces of the outer shells. The adhesive which is used on these contact surfaces tends to contract when it dries but the outer shells can bend and serve to minimize the tendency of the mirror to warp. 5 figures.

  17. Bone image segmentation.

    PubMed

    Liu, Z Q; Liew, H L; Clement, J G; Thomas, C D

    1999-05-01

    Characteristics of microscopic structures in bone cross sections carry essential clues in age determination in forensic science and in the study of age-related bone developments and bone diseases. Analysis of bone cross sections represents a major area of research in bone biology. However, traditional approaches in bone biology have relied primarily on manual processes with very limited number of bone samples. As a consequence, it is difficult to reach reliable and consistent conclusions. In this paper we present an image processing system that uses microstructural and relational knowledge present in the bone cross section for bone image segmentation. This system automates the bone image analysis process and is able to produce reliable results based on quantitative measurements from a large number of bone images. As a result, using large databases of bone images to study the correlation between bone structural features and age-related bone developments becomes feasible.

  18. Compatibility of segmented thermoelectric generators

    NASA Technical Reports Server (NTRS)

    Snyder, J.; Ursell, T.

    2002-01-01

    It is well known that power generation efficiency improves when materials with appropriate properties are combined either in a cascaded or segmented fashion across a temperature gradient. Past methods for determining materials used in segmentation weremainly concerned with materials that have the highest figure of merit in the temperature range. However, the example of SiGe segmented with Bi2Te3 and/or various skutterudites shows a marked decline in device efficiency even though SiGe has the highest figure of merit in the temperature range. The origin of the incompatibility of SiGe with other thermoelectric materials leads to a general definition of compatibility and intrinsic efficiency. The compatibility factor derived as = (Jl+zr - 1) a is a function of only intrinsic material properties and temperature, which is represented by a ratio of current to conduction heat. For maximum efficiency the compatibility factor should not change with temperature both within a single material, and in the segmented leg as a whole. This leads to a measure of compatibility not only between segments, but also within a segment. General temperature trends show that materials are more self compatible at higher temperatures, and segmentation is more difficult across a larger -T. The compatibility factor can be used as a quantitative guide for deciding whether a material is better suited for segmentation orcascading. Analysis of compatibility factors and intrinsic efficiency for optimal segmentation are discussed, with intent to predict optimal material properties, temperature interfaces, and/or currentheat ratios.

  19. Automated medical image segmentation techniques

    PubMed Central

    Sharma, Neeraj; Aggarwal, Lalit M.

    2010-01-01

    Accurate segmentation of medical images is a key step in contouring during radiotherapy planning. Computed topography (CT) and Magnetic resonance (MR) imaging are the most widely used radiographic techniques in diagnosis, clinical studies and treatment planning. This review provides details of automated segmentation methods, specifically discussed in the context of CT and MR images. The motive is to discuss the problems encountered in segmentation of CT and MR images, and the relative merits and limitations of methods currently available for segmentation of medical images. PMID:20177565

  20. Asteroid Redirect Mission: Robotic Segment

    NASA Video Gallery

    This concept animation illustrates the robotic segment of NASA's Asteroid Redirect Mission. The Asteroid Redirect Vehicle, powered by solar electric propulsion, travels to a large asteroid to robot...

  1. 15. The second story in the north segment of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. The second story in the north segment of the building was originally constructed as a restaurant. The north wall of the dining room retains the original wood wainscot and double-hung windows. At some undetermined time, a building was constructed on the adjacent property; blocking the windows in the dining room. Several chimneys with stove-pipe connections occur in the room. The members seen on the floor are part of a system recently installed to support the failing roof. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

  2. Segmenting Words from Natural Speech: Subsegmental Variation in Segmental Cues

    ERIC Educational Resources Information Center

    Rytting, C. Anton; Brew, Chris; Fosler-Lussier, Eric

    2010-01-01

    Most computational models of word segmentation are trained and tested on transcripts of speech, rather than the speech itself, and assume that speech is converted into a sequence of symbols prior to word segmentation. We present a way of representing speech corpora that avoids this assumption, and preserves acoustic variation present in speech. We…

  3. Comparative Sensitivity of Intraoperative Motor Evoked Potential Monitoring in Predicting Postoperative Neurologic Deficits: Nondegenerative versus Degenerative Myelopathy

    PubMed Central

    Clark, Aaron J.; Safaee, Michael; Chou, Dean; Weinstein, Philip R.; Molinaro, Annette M.; Clark, John P.; Mummaneni, Praveen V.

    2015-01-01

    Study Design  Retrospective review. Objective  Intraoperative motor evoked potential (MEP) monitoring in spine surgery may assist surgeons in taking corrective measures to prevent neurologic deficits. The efficacy of monitoring MEPs intraoperatively in patients with myelopathy from nondegenerative causes has not been quantified. We compared the sensitivity and specificity of intraoperative MEP monitoring in patients with myelopathy caused by nondegenerative processes to patients with degenerative cervicothoracic spondylotic myelopathy (CSM). Methods  We retrospectively reviewed our myelopathy surgical cases during a 1-year period to identify patients with degenerative CSM and CSM of nondegenerative causes and collected data on intraoperative MEP changes and postoperative new deficits. Categorical variables were analyzed by Fisher exact test. Receiver operator curves assessed intraoperative MEP monitoring performance in the two groups. Results  In all, 144 patients were identified: 102 had degenerative CSM and 42 had CSM of nondegenerative causes (24 extra-axial tumors, 12 infectious processes, 5 traumatic fractures, and 1 rheumatoid arthritis). For degenerative CSM, there were 11 intraoperative MEP alerts and 7 new deficits (p < 0.001). The corresponding sensitivity was 71% and the specificity was 94%. In the nondegenerative group, there were 11 intraoperative MEP alerts and 3 deficits, which was not significant (p > 0.99). The sensitivity (33%) and specificity (74%) were lower. Among patients with degenerative CSM, the model performed well for predicting postoperative deficits (area under the curve [AUC] 0.826), which appeared better than the nondegenerative group, although it did not reach statistical significance (AUC 0.538, p = 0.16). Conclusions  Based on this large retrospective analysis, intraoperative MEP monitoring in surgery for nondegenerative CSM cases appears to be less sensitive to cord injury and less predictive of postoperative

  4. LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ROOM; THE PIPES AT THE BOTTOM ARE PART OF THE RADIANT HEATING SYSTEM USED FOR HEATING THE FACTORY DURING COLD WEATHER. - Westmoreland Glass Company, Seventh & Kier Streets, Grapeville, Westmoreland County, PA

  5. Biogeochemistry of hydrothermally and adjacent non-altered soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

  6. 12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE CANAL, LOOKING EAST. BARREN AREA IN FOREGROUND IS DECOMPOSING SAWDUST. DIRT PILE IN BACKGROUND IS THE EDGE OF THE SUMMIT COUNTY LANDFILL. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  7. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    SciTech Connect

    Hult, Erin L.; Dickerhoff, Darryl J.; Price, Phillip N.

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

  8. 45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, NORTH END OF MILL NO. 2, WALL ON LEFT DIVIDING CLOTH ROOM ADDED LATER (PROBABLY C. 1970s). - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  9. 11. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  10. 12. View north from the adjacent B & O railroad ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  11. 10. Detail and contextual view of bridge and adjacent farmstead ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  12. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  13. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  14. 8. Exterior view, showing tank and associated piping adjacent to ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Exterior view, showing tank and associated piping adjacent to Test Cell 6, Systems Integration Laboratory Building (T-28), looking south. - Air Force Plant PJKS, Systems Integration Laboratory, Systems Integration Laboratory Building, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  15. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON RIGHT, AND HOUSING AREA ON LEFT. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  16. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ENTRY TO NEIGHBORHOOD. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  17. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF NEIGHBORHOOD. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  18. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ROAD WITH BIRCH CIRCLE. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  19. 3. View of side of house facing north from adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. View of side of house facing north from adjacent property. Original wood siding and trim is visible. Note: later addition to rear of house is shown in right side of photograph. - 322 South Fifteenth Street (House), Louisville, Jefferson County, KY

  20. 22. Float located adjacent to entry stair in filtration bed. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  1. How subaerial salt extrusions influence water quality in adjacent aquifers

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Razieh; Zarei, Mehdi; Raeisi, Ezzat

    2015-12-01

    Brines supplied from salt extrusions cause significant groundwater salinization in arid and semi-arid regions where salt rock is exposed to dissolution by episodic rainfalls. Here we focus on 62 of the 122 diapirs of Hormuz salt emergent in the southern Iran. To consider managing the degradation effect that salt extrusions have on the quality of adjoining aquifers, it is first necessary to understand how they influence adjacent water resources. We evaluate here the impacts that these diapirs have on adjacent aquifers based on investigating their geomorphologies, geologies, hydrologies and hydrogeologies. The results indicate that 28/62 (45%) of our sample of salt diapirs have no significant impact on the quality of groundwater in adjoining aquifers (namely Type N), while the remaining 34/62 (55%) degrade nearby groundwater quality. We offer simple conceptual models that account for how brines flowing from each of these types of salt extrusions contaminate adjacent aquifers. We identify three main mechanisms that lead to contamination: surface impact (Type A), subsurface intrusion (Type B) and indirect infiltration (Type C). A combination of all these mechanisms degrades the water quality in nearby aquifers in 19/62 (31%) of the salt diapirs studied. Having characterized the mechanism(s) by which each diapir affects the adjacent aquifer, we suggest a few possible remediation strategies to be considered. For instance, engineering the surface runoff of diapirs Types A and C into nearby evaporation basins would improve groundwater quality.

  2. MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA FACES SOUTHEAST TOWARD NORTH SIDE OF PUMP HOUSE. INL NEGATIVE NO. 2690. Unknown Photographer, 6/1951. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  3. 1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN BUILDING (BASSIN'S RESTAURANT) (HABS No. DC-357), 501-511 14TH STREET (THE LOCKER ROOM) HABS No. DC-356) ON CORNER, AND MUNSEY BUILDING (HABS No. DC-358) - William J. Stone Building, 1345 E Street Northwest, Washington, District of Columbia, DC

  4. 2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  5. 7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL CONVEYOR; IN THE DISTANCE IS THE FREQUENCY CHANGER HOUSE, WHICH IS ATTACHED TO SWITCH HOUSE NO. 1; LOOKING WEST. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

  6. The Importance of Marketing Segmentation

    ERIC Educational Resources Information Center

    Martin, Gillian

    2011-01-01

    The rationale behind marketing segmentation is to allow businesses to focus on their consumers' behaviors and purchasing patterns. If done effectively, marketing segmentation allows an organization to achieve its highest return on investment (ROI) in turn for its marketing and sales expenses. If an organization markets its products or services to…

  7. Market Segmentation: An Instructional Module.

    ERIC Educational Resources Information Center

    Wright, Peter H.

    A concept-based introduction to market segmentation is provided in this instructional module for undergraduate and graduate transportation-related courses. The material can be used in many disciplines including engineering, business, marketing, and technology. The concept of market segmentation is primarily a transportation planning technique by…

  8. Segmentation: Slicing the Urban Pie.

    ERIC Educational Resources Information Center

    Keim, William A.

    1981-01-01

    Explains market segmentation and defines undifferentiated, concentrated, and differentiated marketing strategies. Describes in detail the marketing planning process at the Metropolitan Community Colleges. Focuses on the development and implementation of an ongoing recruitment program designed for the market segment composed of business employees.…

  9. Synchronized oscillations in a mathematical model of segmentation in zebrafish

    NASA Astrophysics Data System (ADS)

    Liao, Kang-Ling; Shih, Chih-Wen; Tseng, Jui-Pin

    2012-04-01

    Somitogenesis is a process for the development of somites which are transient, segmental structures that lie along the anterior-posterior axis of vertebrate embryos. The pattern of somites is governed by the segmentation clock and its timing is controlled by the clock genes which undergo synchronous oscillation over adjacent cells in the posterior presomitic mesoderm (PSM). In this paper, we analyze a mathematical model which depicts the kinetics of the zebrafish segmentation clock genes subject to direct autorepression by their own products under time delay, and cell-to-cell interaction through Delta-Notch signalling. Our goal is to elucidate how synchronous oscillations are generated for the cells in the posterior PSM, and how oscillations are arrested for the cells in the anterior PSM. For this system of delayed equations, an iteration technique is employed to derive the global convergence to the synchronous equilibrium, which corresponds to the oscillation-arrested. By applying the delay Hopf bifurcation theory and the center manifold theorem, we derive the criteria for the existence of stable synchronous oscillations for the cells at the tail bud of the PSM. Our analysis provides the basic parameter ranges and delay magnitudes for stable synchronous, asynchronous oscillation and oscillation-arrested. We exhibit how synchronous oscillations are affected by the degradation rates and delays. Extended from the analytic theory, further numerical findings linked to the segmentation process are presented.

  10. Fast CEUS image segmentation based on self organizing maps

    NASA Astrophysics Data System (ADS)

    Paire, Julie; Sauvage, Vincent; Albouy-Kissi, Adelaïde; Ladam Marcus, Viviane; Marcus, Claude; Hoeffel, Christine

    2014-03-01

    Contrast-enhanced ultrasound (CEUS) has recently become an important technology for lesion detection and characterization. CEUS is used to investigate the perfusion kinetics in tissue over time, which relates to tissue vascularization. In this paper, we present an interactive segmentation method based on the neural networks, which enables to segment malignant tissue over CEUS sequences. We use Self-Organizing-Maps (SOM), an unsupervised neural network, to project high dimensional data to low dimensional space, named a map of neurons. The algorithm gathers the observations in clusters, respecting the topology of the observations space. This means that a notion of neighborhood between classes is defined. Adjacent observations in variables space belong to the same class or related classes after classification. Thanks to this neighborhood conservation property and associated with suitable feature extraction, this map provides user friendly segmentation tool. It will assist the expert in tumor segmentation with fast and easy intervention. We implement SOM on a Graphics Processing Unit (GPU) to accelerate treatment. This allows a greater number of iterations and the learning process to converge more precisely. We get a better quality of learning so a better classification. Our approach allows us to identify and delineate lesions accurately. Our results show that this method improves markedly the recognition of liver lesions and opens the way for future precise quantification of contrast enhancement.

  11. Liver segmentation for CT images using GVF snake

    SciTech Connect

    Liu Fan; Zhao Binsheng; Kijewski, Peter K.; Wang Liang; Schwartz, Lawrence H.

    2005-12-15

    Accurate liver segmentation on computed tomography (CT) images is a challenging task especially at sites where surrounding tissues (e.g., stomach, kidney) have densities similar to that of the liver and lesions reside at the liver edges. We have developed a method for semiautomatic delineation of the liver contours on contrast-enhanced CT images. The method utilizes a snake algorithm with a gradient vector flow (GVF) field as its external force. To improve the performance of the GVF snake in the segmentation of the liver contour, an edge map was obtained with a Canny edge detector, followed by modifications using a liver template and a concavity removal algorithm. With the modified edge map, for which unwanted edges inside the liver were eliminated, the GVF field was computed and an initial liver contour was formed. The snake algorithm was then applied to obtain the actual liver contour. This algorithm was extended to segment the liver volume in a slice-by-slice fashion, where the result of the preceding slice constrained the segmentation of the adjacent slice. 551 two-dimensional liver images from 20 volumetric images with colorectal metastases spreading throughout the livers were delineated using this method, and also manually by a radiologist for evaluation. The difference ratio, which is defined as the percentage ratio of mismatching volume between the computer and the radiologist's results, ranged from 2.9% to 7.6% with a median value of 5.3%.

  12. Unsupervised segmentation of MRI knees using image partition forests

    NASA Astrophysics Data System (ADS)

    Marčan, Marija; Voiculescu, Irina

    2016-03-01

    Nowadays many people are affected by arthritis, a condition of the joints with limited prevention measures, but with various options of treatment the most radical of which is surgical. In order for surgery to be successful, it can make use of careful analysis of patient-based models generated from medical images, usually by manual segmentation. In this work we show how to automate the segmentation of a crucial and complex joint -- the knee. To achieve this goal we rely on our novel way of representing a 3D voxel volume as a hierarchical structure of partitions which we have named Image Partition Forest (IPF). The IPF contains several partition layers of increasing coarseness, with partitions nested across layers in the form of adjacency graphs. On the basis of a set of properties (size, mean intensity, coordinates) of each node in the IPF we classify nodes into different features. Values indicating whether or not any particular node belongs to the femur or tibia are assigned through node filtering and node-based region growing. So far we have evaluated our method on 15 MRI knee images. Our unsupervised segmentation compared against a hand-segmented gold standard has achieved an average Dice similarity coefficient of 0.95 for femur and 0.93 for tibia, and an average symmetric surface distance of 0.98 mm for femur and 0.73 mm for tibia. The paper also discusses ways to introduce stricter morphological and spatial conditioning in the bone labelling process.

  13. Texture descriptor approaches to level set segmentation in medical images

    NASA Astrophysics Data System (ADS)

    Olveres, Jimena; Nava, Rodrigo; Moya-Albor, Ernesto; Escalante-Ramírez, Boris; Brieva, Jorge; Cristóbal, Gabriel; Vallejo, Enrique

    2014-05-01

    Medical image analysis has become an important tool for improving medical diagnosis and planning treatments. It involves volume or still image segmentation that plays a critical role in understanding image content by facilitating extraction of the anatomical organ or region-of-interest. It also may help towards the construction of reliable computer-aided diagnosis systems. Specifically, level set methods have emerged as a general framework for image segmentation; such methods are mainly based on gradient information and provide satisfactory results. However, the noise inherent to images and the lack of contrast information between adjacent regions hamper the performance of the algorithms, thus, others proposals have been suggested in the literature. For instance, characterization of regions as statistical parametric models to handle level set evolution. In this paper, we study the influence of texture on a level-set-based segmentation and propose the use of Hermite features that are incorporated into the level set model to improve organ segmentation that may be useful for quantifying left ventricular blood flow. The proposal was also compared against other texture descriptors such as local binary patterns, Image derivatives, and Hounsfield low attenuation values.

  14. Optimal segmentation and packaging process

    DOEpatents

    Kostelnik, Kevin M.; Meservey, Richard H.; Landon, Mark D.

    1999-01-01

    A process for improving packaging efficiency uses three dimensional, computer simulated models with various optimization algorithms to determine the optimal segmentation process and packaging configurations based on constraints including container limitations. The present invention is applied to a process for decontaminating, decommissioning (D&D), and remediating a nuclear facility involving the segmentation and packaging of contaminated items in waste containers in order to minimize the number of cuts, maximize packaging density, and reduce worker radiation exposure. A three-dimensional, computer simulated, facility model of the contaminated items are created. The contaminated items are differentiated. The optimal location, orientation and sequence of the segmentation and packaging of the contaminated items is determined using the simulated model, the algorithms, and various constraints including container limitations. The cut locations and orientations are transposed to the simulated model. The contaminated items are actually segmented and packaged. The segmentation and packaging may be simulated beforehand. In addition, the contaminated items may be cataloged and recorded.

  15. The High Prevalence of Symptomatic Degenerative Lumbar Osteoarthritis in Chinese Adults

    PubMed Central

    Liu, Yajun; Xiao, Bin; Han, Xiao

    2014-01-01

    Study Design. A population-based study. Objective. To study the prevalence and features of symptomatic degenerative lumbar osteoarthritis in adults. Summary of Background Data. Lumbar osteoarthritis adversely affects individuals and is a heavy burden. There are limited data on the prevalence of lumbar osteoarthritis. Methods. A representative, multistage sample of adults was collected. Symptomatic degenerative lumbar osteoarthritis was diagnosed by clinical symptoms, physical examinations, and imaging examinations. Personal information was obtained by face-to-face interview. Information included the place of residence, age, sex, income, type of medical insurance, education level, body mass index, habits of smoking and drinking, type of work, working posture, duration of the same working posture during the day, mode of transportation, exposure to vibration, and daily amount of sleep. Crude and adjusted prevalence was calculated. The features of populations were analyzed by multivariable logistic regression in total and subgroup populations. Results. The study included 3859 adults. The crude and adjusted prevalence of lumbar osteoarthritis was 9.02% and 8.90%, respectively. There was no significant difference in the prevalence of lumbar osteoarthritis between urban, suburban, and rural populations (7.66%, 9.97%, and 9.44%) (P = 0.100). The prevalence of lumbar osteoarthritis was higher in females (10.05%) than in males (9.1%, P = 0.021). The prevalence of lumbar osteoarthritis increased with increasing age. Obese people (body mass index >28 kg/m2), those engaged in physical work, those who maintained the same work posture for 1 to 1.9 hours per day, those who were exposed to vibration during daily work, and those who got less than 7 hours of sleep per day had a higher prevalence. These features differed by subgroup. Conclusion. This study established epidemiological baseline data for degenerative lumbar osteoarthritis in adults, especially for people younger than 45

  16. The LOFT ground segment

    NASA Astrophysics Data System (ADS)

    Bozzo, E.; Antonelli, A.; Argan, A.; Barret, D.; Binko, Pavel; Brandt, S.; Cavazzuti, E.; Courvoisier, T.; den Herder, J. W.; Feroci, M.; Ferrigno, C.; Giommi, P.; Götz, D.; Guy, L.; Hernanz, M.; in't Zand, J. J. M.; Klochkov, D.; Kuulkers, Erik; Motch, C.; Lumb, D.; Papitto, A.; Pittori, Carlotta; Rohlfs, R.; Santangelo, A.; Schmid, C.; Schwope, A. D.; Smith, P. J.; Webb, N. A.; Wilms, J.; Zane, S.

    2014-07-01

    LOFT, the Large Observatory For X-ray Timing, was one of the ESA M3 mission candidates that completed their assessment phase at the end of 2013. LOFT is equipped with two instruments, the Large Area Detector (LAD) and the Wide Field Monitor (WFM). The LAD performs pointed observations of several targets per orbit (~90 minutes), providing roughly ~80 GB of proprietary data per day (the proprietary period will be 12 months). The WFM continuously monitors about 1/3 of the sky at a time and provides data for about ~100 sources a day, resulting in a total of ~20 GB of additional telemetry. The LOFT Burst alert System additionally identifies on-board bright impulsive events (e.g., Gamma-ray Bursts, GRBs) and broadcasts the corresponding position and trigger time to the ground using a dedicated system of ~15 VHF receivers. All WFM data are planned to be made public immediately. In this contribution we summarize the planned organization of the LOFT ground segment (GS), as established in the mission Yellow Book1. We describe the expected GS contributions from ESA and the LOFT consortium. A review is provided of the planned LOFT data products and the details of the data flow, archiving and distribution. Despite LOFT was not selected for launch within the M3 call, its long assessment phase ( >2 years) led to a very solid mission design and an efficient planning of its ground operations.

  17. Evolution of segmented strings

    NASA Astrophysics Data System (ADS)

    Gubser, Steven S.

    2016-11-01

    I explain how to evolve segmented strings in de Sitter and anti-de Sitter spaces of any dimension in terms of forward-directed null displacements. The evolution is described entirely in terms of discrete hops which do not require a continuum spacetime. Moreover, the evolution rule is purely algebraic, so it can be defined not only on ordinary real de Sitter and anti-de Sitter but also on the rational points of the quadratic equations that define these spaces. For three-dimensional anti-de Sitter space, a simpler evolution rule is possible that descends from the Wess-Zumino-Witten equations of motion. In this case, one may replace three-dimensional anti-de Sitter space by a noncompact discrete subgroup of S L (2 ,R ) whose structure is related to the Pell equation. A discrete version of the Bañados-Teitelboim-Zanelli (BTZ) black hole can be constructed as a quotient of this subgroup. This discrete black hole avoids the firewall paradox by a curious mechanism: even for large black holes, there are no points inside the horizon until one reaches the singularity.

  18. LSM: perceptually accurate line segment merging

    NASA Astrophysics Data System (ADS)

    Hamid, Naila; Khan, Nazar

    2016-11-01

    Existing line segment detectors tend to break up perceptually distinct line segments into multiple segments. We propose an algorithm for merging such broken segments to recover the original perceptually accurate line segments. The algorithm proceeds by grouping line segments on the basis of angular and spatial proximity. Then those line segment pairs within each group that satisfy unique, adaptive mergeability criteria are successively merged to form a single line segment. This process is repeated until no more line segments can be merged. We also propose a method for quantitative comparison of line segment detection algorithms. Results on the York Urban dataset show that our merged line segments are closer to human-marked ground-truth line segments compared to state-of-the-art line segment detection algorithms.

  19. Spatial scale of motion segmentation from speed cues

    NASA Technical Reports Server (NTRS)

    Mestre, D. R.; Masson, G. S.; Stone, L. S.

    2001-01-01

    For the accurate perception of multiple, potentially overlapping, surfaces or objects, the visual system must distinguish different local motion vectors and selectively integrate similar motion vectors over space to segment the retinal image properly. We recently showed that large differences in speed are required to yield a percept of motion transparency. In the present study, to investigate the spatial scale of motion segmentation from speed cues alone, we measured the speed-segmentation threshold (the minimum speed difference required for 75% performance accuracy) for 'corrugated' random-dot patterns, i.e. patterns in which dots with two different speeds were alternately placed in adjacent bars of variable width. In a first experiment, we found that, at large bar widths, a smaller speed difference was required to segment and perceive the corrugated pattern of moving dots, while at small bar-widths, a larger speed difference was required to segment the two speeds and perceive two transparent surfaces of moving dots. Both the perceptual and segmentation performance transitions occurred at a bar width of around 0.4 degrees. In a second experiment, speed-segmentation thresholds were found to increase sharply when dots with different speeds were paired within a local pooling area. The critical pairing distance was about 0.2 degrees in the fovea and increased linearly with stimulus eccentricity. However, across the range of eccentricities tested (up to 15 degrees ), the critical pairing distance did not change much and remained close to the receptive field size of neurons within the primate primary visual cortex. In a third experiment, increasing dot density changed the relationship between speed-segmentation thresholds and bar width. Thresholds decreased for large bar widths, but increased for small bar widths. All of these results are well fit by a simple stochastic model, which estimates the probabilities of having identical or different motion vectors within a

  20. Multi-atlas pancreas segmentation: Atlas selection based on vessel structure.

    PubMed

    Karasawa, Ken'ichi; Oda, Masahiro; Kitasaka, Takayuki; Misawa, Kazunari; Fujiwara, Michitaka; Chu, Chengwen; Zheng, Guoyan; Rueckert, Daniel; Mori, Kensaku

    2017-03-31

    Automated organ segmentation from medical images is an indispensable component for clinical applications such as computer-aided diagnosis (CAD) and computer-assisted surgery (CAS). We utilize a multi-atlas segmentation scheme, which has recently been used in different approaches in the literature to achieve more accurate and robust segmentation of anatomical structures in computed tomography (CT) volume data. Among abdominal organs, the pancreas has large inter-patient variability in its position, size and shape. Moreover, the CT intensity of the pancreas closely resembles adjacent tissues, rendering its segmentation a challenging task. Due to this, conventional intensity-based atlas selection for pancreas segmentation often fails to select atlases that are similar in pancreas position and shape to those of the unlabeled target volume. In this paper, we propose a new atlas selection strategy based on vessel structure around the pancreatic tissue and demonstrate its application to a multi-atlas pancreas segmentation. Our method utilizes vessel structure around the pancreas to select atlases with high pancreatic resemblance to the unlabeled volume. Also, we investigate two types of applications of the vessel structure information to the atlas selection. Our segmentations were evaluated on 150 abdominal contrast-enhanced CT volumes. The experimental results showed that our approach can segment the pancreas with an average Jaccard index of 66.3% and an average Dice overlap coefficient of 78.5%.

  1. Interactive and scale invariant segmentation of the rectum/sigmoid via user-defined templates

    NASA Astrophysics Data System (ADS)

    Lüddemann, Tobias; Egger, Jan

    2016-03-01

    Among all types of cancer, gynecological malignancies belong to the 4th most frequent type of cancer among women. Besides chemotherapy and external beam radiation, brachytherapy is the standard procedure for the treatment of these malignancies. In the progress of treatment planning, localization of the tumor as the target volume and adjacent organs of risks by segmentation is crucial to accomplish an optimal radiation distribution to the tumor while simultaneously preserving healthy tissue. Segmentation is performed manually and represents a time-consuming task in clinical daily routine. This study focuses on the segmentation of the rectum/sigmoid colon as an Organ-At-Risk in gynecological brachytherapy. The proposed segmentation method uses an interactive, graph-based segmentation scheme with a user-defined template. The scheme creates a directed two dimensional graph, followed by the minimal cost closed set computation on the graph, resulting in an outlining of the rectum. The graphs outline is dynamically adapted to the last calculated cut. Evaluation was performed by comparing manual segmentations of the rectum/sigmoid colon to results achieved with the proposed method. The comparison of the algorithmic to manual results yielded to a Dice Similarity Coefficient value of 83.85+/-4.08%, in comparison to 83.97+/-8.08% for the comparison of two manual segmentations of the same physician. Utilizing the proposed methodology resulted in a median time of 128 seconds per dataset, compared to 300 seconds needed for pure manual segmentation.

  2. A Segmental Framework for Representing Signs Phonetically

    ERIC Educational Resources Information Center

    Johnson, Robert E.; Liddell, Scott K.

    2011-01-01

    The arguments for dividing the signing stream in signed languages into sequences of phonetic segments are compelling. The visual records of instances of actually occurring signs provide evidence of two basic types of segments: postural segments and trans-forming segments. Postural segments specify an alignment of articulatory features, both manual…

  3. Bipolar and Major Depressive Disorder: Neuroimaging the Developmental-Degenerative Divide

    PubMed Central

    Savitz, Jonathan; Drevets, Wayne C

    2010-01-01

    Both major depressive disorder and bipolar disorder are the subject of a voluminous imaging and genetics literature. Here, we attempt a comprehensive review of MRI and metabolic PET studies conducted to date on these two disorders, and interpret our findings from the perspective of developmental and degenerative models of illness. Elevated activity and volume loss of the hippocampus, orbital and ventral prefrontal cortex are recurrent themes in the literature. In contrast, dorsal aspects of the PFC tend to display hypometabolism. Ventriculomegaly and white matter hyperintensities are intimately associated with depression in elderly populations and likely have a vascular origin. Important confounding influences are medication, phenotypic and genetic heterogeneity, and technological limitations. We suggest that environmental stress and genetic risk variants interact with each other in a complex manner to alter neural circuitry and precipitate illness. Imaging genetic approaches hold out promise for advancing our understanding of affective illness. PMID:19428491

  4. Contribution of the cerebellum to neuropsychological functioning: evidence from a case of cerebellar degenerative disorder.

    PubMed

    Akshoomoff, N A; Courchesne, E; Press, G A; Iragui, V

    1992-04-01

    A detailed neuropsychological evaluation was performed on a patient with an idiopathic cerebellar degenerative disorder. Significant deficits were found in verbal and nonverbal intelligence, verbal associative learning, and visuospatial skills. These deficits were not readily explained by motor control difficulties. In contrast to the patient's moderately impaired language abilities, he was severely impaired on a test of verbal fluency and demonstrated mild naming deficits. Severe cerebellar parenchymal volume loss was demonstrated by magnetic resonance examination. Supratentorial structures showed only minimal posterior parietal and occipital sulcal prominence. On neurological examination, this patient had signs of severe involvement of the cerebellar systems and mild-to-moderate dysfunction of the corticospinal tract. As is characteristic of patients with cerebellar degeneration, there was neurophysiological evidence of subclinical involvement of auditory and somatosensory pathways at the level of the brain stem. Since relatively little cerebral cortical atrophy was noted in this patient, these findings suggest that an intact cerebellum is important for normal cognitive functions.

  5. Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints.

    PubMed

    Shur, Natalie; Corrigan, Alexis; Agrawal, Kanhaiyalal; Desai, Amidevi; Gnanasegaran, Gopinath

    2015-01-01

    The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision.

  6. Radiological and Radionuclide Imaging of Degenerative Disease of the Facet Joints

    PubMed Central

    Shur, Natalie; Corrigan, Alexis; Agrawal, Kanhaiyalal; Desai, Amidevi; Gnanasegaran, Gopinath

    2015-01-01

    The facet joint has been increasingly implicated as a potential source of lower back pain. Diagnosis can be challenging as there is not a direct correlation between facet joint disease and clinical or radiological features. The purpose of this article is to review the diagnosis, treatment, and current imaging modality options in the context of degenerative facet joint disease. We describe each modality in turn with a pictorial review using current evidence. Newer hybrid imaging techniques such as single photon emission computed tomography/computed tomography (SPECT/CT) provide additional information relative to the historic gold standard magnetic resonance imaging. The diagnostic benefits of SPECT/CT include precise localization and characterization of spinal lesions and improved diagnosis for lower back pain. It may have a role in selecting patients for local therapeutic injections, as well as guiding their location with increased precision. PMID:26170560

  7. Novel nano-composite multi-layered biomaterial for the treatment of multifocal degenerative cartilage lesions.

    PubMed

    Kon, Elizaveta; Delcogliano, M; Filardo, G; Altadonna, G; Marcacci, M

    2009-11-01

    We report on a 46-year-old athletic patient, previously treated with anterior cruciate ligament reconstruction, with large degenerative chondral lesions of the medial femoral condyle, trochlea and patella, which was successfully treated with a closing-wedge high tibial osteotomy and the implant of a newly developed biomimetic nanostructured osteochondral bioactive scaffold. After 1 year of follow-up the patient was pain-free, had full knee range of motion, and had returned to his pre-operation level of athletic activity. MRI evaluation at 6 months showed that the implant gave a hyaline-like signal as well as a good restoration of the articular surface, with minimal subchondral bone oedema. Subchondral oedema was almost non-visible at 12 months.

  8. Impact of changes in extracellular matrix in the lumbar degenerative disc

    PubMed Central

    Ciurea, AV; Mitrica, M; Mohan, A

    2011-01-01

    The complexity of the clinical, biochemical, hystochemical and immunologic aspects of the intervertebral disk, along with its molecular biology, justifies the object of our study on the extracellular matrix modifications in lumbar disk hernias and their impact on patient quality of life. Material and method: the research lot was composed of 50 patients, aged between 18 and 73, who have undergone lumbar disk hernia surgery. MMP–9 (metalloproteinase–9) and TIMP–1 (tissue inhibitor of matrix metalloprotease 1) have been dosed in order to study the modifications on extracellular disk matrix, and quality of life assessment was carried out both in pre–operatory and post–operatory periods. Conclusions: patients may prevent the appearance of degenerative processes of the intervertebral disk with care and responsibility by controlling their weight, avoiding intense physical activities and ceasing to smoke. PMID:22567050

  9. [Drinking water hardness and chronic degenerative diseases. I. Analysis of epidemiological research].

    PubMed

    Nardi, G; Donato, F; Monarca, S; Gelatti, U

    2003-01-01

    For many years a causal relation between drinking water hardness and cardiovascular or other chronic degenerative diseases in humans has been hypothesized. In order to evaluate the association between the concentration of minerals (calcium and magnesium) responsible for the hardness of drinking water and human health, a review of all the articles published on the subject from 1980 up to today has been carried out. The retrieved articles have been divided into 4 categories: geographic correlation studies, cross-sectional studies, case-control and cohort studies, and clinical trials. The methods for the selection of the articles and the extraction and analysis of the data are detailed in this paper. Epidemiological studies have been reviewed critically, and some conclusions have been drawn taking into account the research in basic sciences and experimental studies. However, a formal meta-analysis has not been performed, due to the heterogeneity of measures of effect among the different studies.

  10. Degenerative mitral valve disease-contemporary surgical approaches and repair techniques.

    PubMed

    Koprivanac, Marijan; Kelava, Marta; Alansari, Shehab; Javadikasgari, Hoda; Tappuni, Bassman; Mick, Stephanie; Marc, Gillinov A; Suri, Rakesh; Mihaljevic, Tomislav

    2017-01-01

    Given the increasing age of the US population and the accompanying rise in cardiovascular disease, we expect to see an increasing number of patients affected by degenerative mitral valve disease in a more complex patient population. Therefore, increasing the overall rate of mitral valve repair will become even more important than it is today, and the capability to provide a universally and uniformly accepted quality of repair will have important medical, economic, and societal implications. This article will describe preoperative and intraoperative considerations and the currently practiced mitral valve repair approaches and techniques. The aim of the article is to present our contemporary approach to mitral valve repair in the hope that it can be adopted at other institutions that may have low repair rates. Adoption of simple and reproducible mitral valve repair techniques is of paramount importance if we as a profession are to accomplish overall higher rates of mitral valve repair with optimal outcomes.

  11. Effects of athletic conditioning on horses with degenerative suspensory ligament desmitis: a preliminary report.

    PubMed

    Xie, Lin; Spencer, Nakia D; Beadle, Ralph E; Gaschen, Lorrie; Buchert, Mark R; Lopez, Mandi J

    2011-07-01

    Equine degenerative suspensory ligament desmitis (DSLD) is a debilitating condition that has limited response to rest and stall confinement. This study was designed to test the hypothesis that mild to moderate DSLD is not worsened by consistent exercise. Paso Fino and Peruvian Paso horses (two normal horses and four horses with DSLD) were exercised for 30 min every other day for 8 weeks and then pasture rested for 4 months. Gait analysis, radiographs, ultrasound and serum insulin and glucose concentrations were performed prior to the exercise trial and at each time point. Vertical impulse increased after 8 weeks of exercise and 4 months of pasture rest in DSLD-affected horses. Suspensory ligament fiber pattern subjectively improved with exercise in affected horses. Insulin levels significantly decreased from baseline in all horses after 4 and 8 weeks of exercise. Exercise did not seem to exacerbate and may have improved signs of DSLD in mild to moderate cases.

  12. Histochemical and morphometric studies of peripheral muscle in bovine progressive degenerative myeloencephalopathy of brown Swiss cattle.

    PubMed

    Oyster, R; Leipold, H W; Troyer, D; Cash, W; Johnson, D

    1992-06-01

    Histochemical and morphometric analysis of selected skeletal muscles was performed on 14 pure bred, Brown Swiss cattle. Nine cattle were clinically affected with bovine progressive degenerative myeloencephalopathy (BPDME) while five served as controls. Statistically significant trend differences were not observed for the parameters of mean cross sectional area, and mean fiber type percentages for types, I, IIA, and IIB fibers between affected and control test groups. In general, patterns of hypertrophy or atrophy, fiber type grouping, fiber type predominance, or fiber cross sectional profile alteration were not observed in the muscles examined from affected cattle. The findings suggest that BPDME, or weaver syndrome, is not a muscular dystrophy and that muscle pathology is not a primary part of the syndrome nor would muscle pathology be expected to contribute significantly to the clinical signs of the disease.

  13. A heme oxygenase-1 transducer model of degenerative and developmental brain disorders.

    PubMed

    Schipper, Hyman M; Song, Wei

    2015-03-09

    Heme oxygenase-1 (HO-1) is a 32 kDa protein which catalyzes the breakdown of heme to free iron, carbon monoxide and biliverdin. The Hmox1 promoter contains numerous consensus sequences that render the gene exquisitely sensitive to induction by diverse pro-oxidant and inflammatory stimuli. In "stressed" astroglia, HO-1 hyperactivity promotes mitochondrial iron sequestration and macroautophagy and may thereby contribute to the pathological iron deposition and bioenergetic failure documented in Alzheimer disease, Parkinson disease and certain neurodevelopmental conditions. Glial HO-1 expression may also impact neuroplasticity and cell survival by modulating brain sterol metabolism and the proteasomal degradation of neurotoxic proteins. The glial HO-1 response may represent a pivotal transducer of noxious environmental and endogenous stressors into patterns of neural damage and repair characteristic of many human degenerative and developmental CNS disorders.

  14. Evidence of oxidative injury of the spinal cord in 2 horses with equine degenerative myeloencephalopathy.

    PubMed

    Wong, D M; Ghosh, A; Fales-Williams, A J; Haynes, J S; Kanthasamy, A G

    2012-11-01

    The cervical spinal cords of 2 horses with equine degenerative myeloencephalopathy (EDM) were evaluated for evidence of oxidative damage to the central nervous system (CNS) using immunohistochemical staining for 3-nitrotyrosine (3-NT) and 4-hydroxynonenol (4-HNE). Neurons of the CNS from horses with EDM had positive immunohistochemical staining, whereas control samples did not, thus supporting the theory that oxidative damage is a potential underlying factor in horses with EDM. In addition, serum vitamin E concentration was low in both EDM-affected horses, and vitamin E concentration was also deficient in the cerebrospinal fluid in 1 EDM horse, further supporting the association between low vitamin E concentrations and oxidative damage to the CNS. Continued research is necessary to further define the pathophysiologic mechanisms of EDM.

  15. Degenerative mitral valve disease-contemporary surgical approaches and repair techniques

    PubMed Central

    Kelava, Marta; Alansari, Shehab; Javadikasgari, Hoda; Tappuni, Bassman; Mick, Stephanie; Marc, Gillinov A.; Suri, Rakesh; Mihaljevic, Tomislav

    2017-01-01

    Given the increasing age of the US population and the accompanying rise in cardiovascular disease, we expect to see an increasing number of patients affected by degenerative mitral valve disease in a more complex patient population. Therefore, increasing the overall rate of mitral valve repair will become even more important than it is today, and the capability to provide a universally and uniformly accepted quality of repair will have important medical, economic, and societal implications. This article will describe preoperative and intraoperative considerations and the currently practiced mitral valve repair approaches and techniques. The aim of the article is to present our contemporary approach to mitral valve repair in the hope that it can be adopted at other institutions that may have low repair rates. Adoption of simple and reproducible mitral valve repair techniques is of paramount importance if we as a profession are to accomplish overall higher rates of mitral valve repair with optimal outcomes. PMID:28203540

  16. Use of (/sup 99m/Tc)-HM-PAO in the diagnosis of primary degenerative dementia

    SciTech Connect

    Testa, H.J.; Snowden, J.S.; Neary, D.; Shields, R.A.; Burjan, A.W.; Prescott, M.C.; Northen, B.; Goulding, P.

    1988-12-01

    The clinical value of single photon emission computed tomography (SPECT) in the differential diagnosis of dementia due to cerebral atrophy was evaluated by comparing the pattern of distribution (/sup 99m/Tc)-HM-PAO in three dementing conditions. Imaging was carried out in 26 patients with suspected Alzheimer's disease, 14 with dementia of the frontal-lobe type, and 13 with progressive supranuclear palsy. Images were evaluated and reported without knowledge of clinical diagnosis with respect to regions of reduced uptake of tracer. Reduced uptake in the posterior cerebral hemispheres was characteristic of Alzheimer's disease, while selective anterior hemisphere abnormalities characterized both dementia of the frontal-lobe type and progressive supranuclear palsy. The latter conditions could be distinguished on the basis of the appearance of integrity of the rim of the frontal cortex. The technique has an important role in the differentiation of degenerative dementias.

  17. Prognosis of intervertebral disc loss from diagnosis of degenerative disc disease

    NASA Astrophysics Data System (ADS)

    Li, S.; Lin, A.; Tay, K.; Romano, W.; Osman, Said

    2015-03-01

    Degenerative Disc Disease (DDD) is one of the most common causes of low back pain, and is a major factor in limiting the quality of life of an individual usually as they enter older stages of life, the disc degeneration reduces the shock absorption available which in turn causes pain. Disc loss is one of the central processes in the pathogenesis of DDD. In this study, we investigated whether the image texture features quantified from magnetic resonance imaging (MRI) could be appropriate markers for diagnosis of DDD and prognosis of inter-vertebral disc loss. The main objective is to use simple image based biomarkers to perform prognosis of spinal diseases using non-invasive procedures. Our results from 65 subjects proved the higher success rates of the combination marker compared to the individual markers and in the future, we will extend the study to other spine regions to allow prognosis and diagnosis of DDD for a wider region.

  18. Astrocytes As the Main Players in Primary Degenerative Disorders of the Human Central Nervous System

    PubMed Central

    Capani, Francisco; Quarracino, Cecilia; Caccuri, Roberto; Sica, Roberto E. P.

    2016-01-01

    Along the last years it has been demonstrated that non-neural cells play a major role in the pathogenesis of the primary degenerative disorders (PDDs) of the human central nervous system. Among them, astrocytes coordinate and participate in many different and complex metabolic processes, in close interaction with neurons. Moreover, increasing experimental evidence hints an early astrocytic dysfunction in these diseases. In this mini review we summarize the astrocytic behavior in PDDs, with special consideration to the experimental observations where astrocytic pathology precedes the development of neuronal dysfunction. We also suggest a different approach that could be consider in human investigations in Alzheimer’s and Parkinson’s disease. We believe that the study of PDDs with human brain samples may hold the key of a paradigmatic physiopathological process in which astrocytes might be the main players. PMID:26973519

  19. Astrocytes As the Main Players in Primary Degenerative Disorders of the Human Central Nervous System.

    PubMed

    Capani, Francisco; Quarracino, Cecilia; Caccuri, Roberto; Sica, Roberto E P

    2016-01-01

    Along the last years it has been demonstrated that non-neural cells play a major role in the pathogenesis of the primary degenerative disorders (PDDs) of the human central nervous system. Among them, astrocytes coordinate and participate in many different and complex metabolic processes, in close interaction with neurons. Moreover, increasing experimental evidence hints an early astrocytic dysfunction in these diseases. In this mini review we summarize the astrocytic behavior in PDDs, with special consideration to the experimental observations where astrocytic pathology precedes the development of neuronal dysfunction. We also suggest a different approach that could be consider in human investigations in Alzheimer's and Parkinson's disease. We believe that the study of PDDs with human brain samples may hold the key of a paradigmatic physiopathological process in which astrocytes might be the main players.

  20. Autosomal dominant (Beukes) premature degenerative osteoarthropathy of the hip joint unlinked to COL2A1

    SciTech Connect

    Beighton, P.; Ramesar, R.; Cilliers, H.J.

    1994-12-01

    Molecular investigations have been undertaken in several separate large South African families with autosomal dominant skeletal dysplasias in which premature degenerative osteoarthropathy of the hip joint was the major manifestation. There are sometimes additional minor changes in the spine and these conditions fall into the general spondyloepiphyseal dysplasia (SED) nosological category. In some kindreds, linkage between phenotype and the type II collagen gene (COL2A1) has been established, while in others there is no linkage. We have now completed molecular linkage investigations in an Afrikaner family named Beukes, in which 47 members in 6 generations have premature osteoarthropathy of the hip joint. A LOD score of minus infinity indicates that this condition is not the result of a defect of the COL2A1 gene. 12 refs., 2 figs., 1 tab.

  1. Cognitive profiles in degenerative dementia without evidence of small vessel pathology and small vessel vascular dementia.

    PubMed

    De Carolis, Antonella; Cipollini, Virginia; Donato, Nicole; Sepe-Monti, Micaela; Orzi, Francesco; Giubilei, Franco

    2017-01-01

    Although a large number of studies have examined possible differences in cognitive performance between Alzheimer's disease (AD) and vascular dementia (VaD), the data in the literature are conflicting. The aims of this study were to analyze the neuropsychological pattern of subjects affected by degenerative dementia without evidence of small vessel pathology (DD) and small vessel VaD subjects in the early stages and to investigate differences in the progression of cognitive impairment. Seventy-five patients with probable VaD and 75 patients with probable DD were included. All the subjects underwent a standard neuropsychological evaluation, including the following test: Visual Search, Attentional matrices, Story Recall, Raven's Coloured Progressive Matrices, Phonological and Semantic Verbal Fluency, Token, and Copying Drawings. The severity of cognitive impairment was stratified according to the MMSE score. Fifteen subjects with probable DD and 10 subjects with probable VaD underwent a 12-month cognitive re-evaluation. No significant difference was found between DD and VaD subjects in any of the neuropsychological tests except Story Recall in the mild cognitive impairment (P < 0.001). The re-test value was significantly worse than the baseline value in the MMSE (P = 0.037), Corsi (P = 0.041), Story Recall (P = 0.032), Phonological Verbal Fluency (P = 0.02), and Copying Drawings (P = 0.043) in DD patients and in the Visual Search test (P = 0.036) in VaD subjects. These results suggest that a neuropsychological evaluation might help to differentiate degenerative dementia without evidence of small vessel pathology from small vessel VaD in the early stages of these diseases.

  2. Multiatlas segmentation as nonparametric regression.

    PubMed

    Awate, Suyash P; Whitaker, Ross T

    2014-09-01

    This paper proposes a novel theoretical framework to model and analyze the statistical characteristics of a wide range of segmentation methods that incorporate a database of label maps or atlases; such methods are termed as label fusion or multiatlas segmentation. We model these multiatlas segmentation problems as nonparametric regression problems in the high-dimensional space of image patches. We analyze the nonparametric estimator's convergence behavior that characterizes expected segmentation error as a function of the size of the multiatlas database. We show that this error has an analytic form involving several parameters that are fundamental to the specific segmentation problem (determined by the chosen anatomical structure, imaging modality, registration algorithm, and label-fusion algorithm). We describe how to estimate these parameters and show that several human anatomical structures exhibit the trends modeled analytically. We use these parameter estimates to optimize the regression estimator. We show that the expected error for large database sizes is well predicted by models learned on small databases. Thus, a few expert segmentations can help predict the database sizes required to keep the expected error below a specified tolerance level. Such cost-benefit analysis is crucial for deploying clinical multiatlas segmentation systems.

  3. Multiatlas Segmentation as Nonparametric Regression

    PubMed Central

    Awate, Suyash P.; Whitaker, Ross T.

    2015-01-01

    This paper proposes a novel theoretical framework to model and analyze the statistical characteristics of a wide range of segmentation methods that incorporate a database of label maps or atlases; such methods are termed as label fusion or multiatlas segmentation. We model these multiatlas segmentation problems as nonparametric regression problems in the high-dimensional space of image patches. We analyze the nonparametric estimator’s convergence behavior that characterizes expected segmentation error as a function of the size of the multiatlas database. We show that this error has an analytic form involving several parameters that are fundamental to the specific segmentation problem (determined by the chosen anatomical structure, imaging modality, registration algorithm, and label-fusion algorithm). We describe how to estimate these parameters and show that several human anatomical structures exhibit the trends modeled analytically. We use these parameter estimates to optimize the regression estimator. We show that the expected error for large database sizes is well predicted by models learned on small databases. Thus, a few expert segmentations can help predict the database sizes required to keep the expected error below a specified tolerance level. Such cost-benefit analysis is crucial for deploying clinical multiatlas segmentation systems. PMID:24802528

  4. Activation of α2A-adrenergic signal transduction in chondrocytes promotes degenerative remodelling of temporomandibular joint

    PubMed Central

    Jiao, Kai; Zeng, Guang; Niu, Li-Na; Yang, Hong-xu; Ren, Gao-tong; Xu, Xin-yue; Li, Fei-fei; Tay, Franklin R.; Wang, Mei-qing

    2016-01-01

    This study tested whether activation of adrenoreceptors in chondrocytes has roles in degenerative remodelling of temporomandibular joint (TMJ) and to determine associated mechanisms. Unilateral anterior crossbite (UAC) was established to induce TMJ degeneration in rats. Saline vehicle, α2- and β-adrenoreceptor antagonists or agonists were injected locally into the TMJ area of UAC rats. Cartilage degeneration, subchondral bone microarchitecture and the expression of adrenoreceptors, aggrecans, matrix metalloproteinases (MMPs) and RANKL by chondrocytes were evaluated. Chondrocytes were stimulated by norepinephrine to investigate signal transduction of adrenoreceptors. Increased α2A-adrenoreceptor expression was observed in condylar cartilage of UAC rats, together with cartilage degeneration and subchondral bone loss. Norepinephrine depresses aggrecans expression but stimulates MMP-3, MMP-13 and RANKL production by chondrocytes through ERK1/2 and PKA pathway; these effects were abolished by an α2A-adrenoreceptor antagonist. Furthermore, inhibition of α2A-adrenoreceptor attenuated degenerative remodelling in the condylar cartilage and subchondral bone, as revealed by increased cartilage thickness, proteoglycans and aggrecan expression, and decreased MMP-3, MMP-13 and RANKL expressions in cartilage, increased BMD, BV/TV, and decreased Tb.Sp in subchondral bone. Conversely, activation of α2A-adrenoreceptor intensified aforementioned degenerative changes in UAC rats. It is concluded that activation of α2A-adrenergic signal in chondrocytes promotes TMJ degenerative remodelling by chondrocyte-mediated pro-catabolic activities. PMID:27452863

  5. One-step labeling of degenerative neurons in unfixed brain tissue samples using Fluoro-Jade C.

    PubMed

    Gu, Qiang; Schmued, Larry C; Sarkar, Sumit; Paule, Merle G; Raymick, Bryan

    2012-06-30

    Neurodegeneration is the underlying cause of a vast majority of neurological disorders and often a result of brain trauma, stroke, or neurotoxic insult. Here we describe a simple method for labeling degenerating neurons in unfixed brain tissue samples. This method could provide a new avenue for identifying and harvesting degenerative neurons from unfixed brain tissues for subsequent molecular analyses.

  6. On the Circulation Manifold for Two Adjacent Lifting Sections

    NASA Technical Reports Server (NTRS)

    Zannetti, Luca; Iollo, Angelo

    1998-01-01

    The circulation functional relative to two adjacent lifting sections is studied for two cases. In the first case we consider two adjacent circles. The circulation is computed as a function of the displacement of the secondary circle along the axis joining the two centers and of the angle of attack of the secondary circle, The gradient of such functional is computed by deriving a set of elliptic functions with respect both to their argument and to their Period. In the second case studied, we considered a wing-flap configuration. The circulation is computed by some implicit mappings, whose differentials with respect to the variation of the geometrical configuration in the physical space are found by divided differences. Configurations giving rise to local maxima and minima in the circulation manifold are presented.

  7. Osmium complex binding to mismatched methylcytosine: effect of adjacent bases.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-01-01

    We investigated the efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes depended on the 5'-neighboring base of the 5-methylcytosine. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique side reaction was observed. However, the mismatched base pairs did not influence the selectivity of osmium complexation with methylated DNA.

  8. Conference room 211, adjacent to commander's quarters, with vault door ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Conference room 211, adjacent to commander's quarters, with vault door at right. Projection area at center is equipped with automatic security drapes. Projection room uses a 45 degree mirror to reflect the image onto the frosted glass screen. Door on far left leads to display area senior battle staff viewing bridge, and the commander's quarters - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  9. 20. Interior view of fuel storage pit or vault adjacent ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. Interior view of fuel storage pit or vault adjacent to Test Cell 9 in Component Test Laboratory (T-27), looking west. Photograph shows upgraded instrumentation, piping, tanks, and technological modifications installed in 1997-99 to accommodate component testing requirements for the Atlas V missile. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  10. Four-body central configurations with adjacent equal masses

    NASA Astrophysics Data System (ADS)

    Deng, Yiyang; Li, Bingyu; Zhang, Shiqing

    2017-04-01

    For any convex non-collinear central configuration of the planar Newtonian 4-body problem with adjacent equal masses m1 =m2 ≠m3 =m4, with equal lengths for the two diagonals, we prove it must possess a symmetry and must be an isosceles trapezoid; furthermore, which is also an isosceles trapezoid when the length between m1 and m4 equals the length between m2 and m3.

  11. Processing multiple non-adjacent dependencies: evidence from sequence learning.

    PubMed

    de Vries, Meinou H; Petersson, Karl Magnus; Geukes, Sebastian; Zwitserlood, Pienie; Christiansen, Morten H

    2012-07-19

    Processing non-adjacent dependencies is considered to be one of the hallmarks of human language. Assuming that sequence-learning tasks provide a useful way to tap natural-language-processing mechanisms, we cross-modally combined serial reaction time and artificial-grammar learning paradigms to investigate the processing of multiple nested (A(1)A(2)A(3)B(3)B(2)B(1)) and crossed dependencies (A(1)A(2)A(3)B(1)B(2)B(3)), containing either three or two dependencies. Both reaction times and prediction errors highlighted problems with processing the middle dependency in nested structures (A(1)A(2)A(3)B(3)_B(1)), reminiscent of the 'missing-verb effect' observed in English and French, but not with crossed structures (A(1)A(2)A(3)B(1)_B(3)). Prior linguistic experience did not play a major role: native speakers of German and Dutch-which permit nested and crossed dependencies, respectively-showed a similar pattern of results for sequences with three dependencies. As for sequences with two dependencies, reaction times and prediction errors were similar for both nested and crossed dependencies. The results suggest that constraints on the processing of multiple non-adjacent dependencies are determined by the specific ordering of the non-adjacent dependencies (i.e. nested or crossed), as well as the number of non-adjacent dependencies to be resolved (i.e. two or three). Furthermore, these constraints may not be specific to language but instead derive from limitations on structured sequence learning.

  12. 38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX GAP ROTARY RECTIFIER. THIS UNIT GENERATED A MAGNETIC PULSE WHICH WAS TRANSMITTED TO THE COLLECTION PLATES IN THE ELECTROSTATIC PRECIPITATOR CHAMBER. THESE PERIODIC PULSES VIBRATE THE PLATES AND CAUSE PRECIPITATED ARTICLES OF SMOKE AND FLY ASH TO FALL TO THE BOTTOM OF THE PRECIPITATOR CHAMBER. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  13. Laser Truss Sensor for Segmented Telescope Phasing

    NASA Technical Reports Server (NTRS)

    Liu, Duncan T.; Lay, Oliver P.; Azizi, Alireza; Erlig, Herman; Dorsky, Leonard I.; Asbury, Cheryl G.; Zhao, Feng

    2011-01-01

    A paper describes the laser truss sensor (LTS) for detecting piston motion between two adjacent telescope segment edges. LTS is formed by two point-to-point laser metrology gauges in a crossed geometry. A high-resolution (<30 nm) LTS can be implemented with existing laser metrology gauges. The distance change between the reference plane and the target plane is measured as a function of the phase change between the reference and target beams. To ease the bandwidth requirements for phase detection electronics (or phase meter), homodyne or heterodyne detection techniques have been used. The phase of the target beam also changes with the refractive index of air, which changes with the air pressure, temperature, and humidity. This error can be minimized by enclosing the metrology beams in baffles. For longer-term (weeks) tracking at the micron level accuracy, the same gauge can be operated in the absolute metrology mode with an accuracy of microns; to implement absolute metrology, two laser frequencies will be used on the same gauge. Absolute metrology using heterodyne laser gauges is a demonstrated technology. Complexity of laser source fiber distribution can be optimized using the range-gated metrology (RGM) approach.

  14. Accounting for segment correlations in segmented gamma-ray scans

    SciTech Connect

    Sheppard, G.A.; Prettyman, T.H.; Piquette, E.C.

    1994-08-01

    In a typical segmented gamma-ray scanner (SGS), the detector`s field of view is collimated so that a complete horizontal slice or segment of the desired thickness is visible. Ordinarily, the collimator is not deep enough to exclude gamma rays emitted from sample volumes above and below the segment aligned with the collimator. This can lead to assay biases, particularly for certain radioactive-material distributions. Another consequence of the collimator`s low aspect ratio is that segment assays at the top and bottom of the sample are biased low because the detector`s field of view is not filled. This effect is ordinarily countered by placing the sample on a low-Z pedestal and scanning one or more segment thicknesses below and above the sample. This takes extra time, however, We have investigated a number of techniques that both account for correlated segments and correct for end effects in SGS assays. Also, we have developed an algorithm that facilitates estimates of assay precision. Six calculation methods have been compared by evaluating the results of thousands of simulated, assays for three types of gamma-ray source distribution and ten masses. We will report on these computational studies and their experimental verification.

  15. Ensemble segmentation using efficient integer linear programming.

    PubMed

    Alush, Amir; Goldberger, Jacob

    2012-10-01

    We present a method for combining several segmentations of an image into a single one that in some sense is the average segmentation in order to achieve a more reliable and accurate segmentation result. The goal is to find a point in the "space of segmentations" which is close to all the individual segmentations. We present an algorithm for segmentation averaging. The image is first oversegmented into superpixels. Next, each segmentation is projected onto the superpixel map. An instance of the EM algorithm combined with integer linear programming is applied on the set of binary merging decisions of neighboring superpixels to obtain the average segmentation. Apart from segmentation averaging, the algorithm also reports the reliability of each segmentation. The performance of the proposed algorithm is demonstrated on manually annotated images from the Berkeley segmentation data set and on the results of automatic segmentation algorithms.

  16. Divergent viral presentation among human tumors and adjacent normal tissues

    PubMed Central

    Cao, Song; Wendl, Michael C.; Wyczalkowski, Matthew A.; Wylie, Kristine; Ye, Kai; Jayasinghe, Reyka; Xie, Mingchao; Wu, Song; Niu, Beifang; Grubb, Robert; Johnson, Kimberly J.; Gay, Hiram; Chen, Ken; Rader, Janet S.; Dipersio, John F.; Chen, Feng; Ding, Li

    2016-01-01

    We applied a newly developed bioinformatics system called VirusScan to investigate the viral basis of 6,813 human tumors and 559 adjacent normal samples across 23 cancer types and identified 505 virus positive samples with distinctive, organ system- and cancer type-specific distributions. We found that herpes viruses (e.g., subtypes HHV4, HHV5, and HHV6) that are highly prevalent across cancers of the digestive tract showed significantly higher abundances in tumor versus adjacent normal samples, supporting their association with these cancers. We also found three HPV16-positive samples in brain lower grade glioma (LGG). Further, recurrent HBV integration at the KMT2B locus is present in three liver tumors, but absent in their matched adjacent normal samples, indicating that viral integration induced host driver genetic alterations are required on top of viral oncogene expression for initiation and progression of liver hepatocellular carcinoma. Notably, viral integrations were found in many genes, including novel recurrent HPV integrations at PTPN13 in cervical cancer. Finally, we observed a set of HHV4 and HBV variants strongly associated with ethnic groups, likely due to viral sequence evolution under environmental influences. These findings provide important new insights into viral roles of tumor initiation and progression and potential new therapeutic targets. PMID:27339696

  17. Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

    PubMed Central

    2015-01-01

    Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage ‘Ci’ given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage ‘Ci’ decreased as both the adjacent P1 and M1 matured. The modal stage at P2 ‘Ci’ was P1 ‘Coc’ (cusp outline complete) and M1 ‘Crc’ (crown complete). Initial mineralisation of P2 was observed up to P1 ‘Crc’ and M1 stage ‘R½’ (root half). The chance of observing P2 at least ‘Coc’ (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond ‘Crc’ and M1 is beyond ‘R½’. PMID:26673218

  18. Fouling assemblages on offshore wind power plants and adjacent substrata

    NASA Astrophysics Data System (ADS)

    Wilhelmsson, Dan; Malm, Torleif

    2008-09-01

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  19. Perceptual processing of adjacent and nonadjacent tactile nontargets.

    PubMed

    Evans, P M; Craig, J C; Rinker, M A

    1992-11-01

    Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation. The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation.

  20. Using BRDFs for accurate albedo calculations and adjacency effect corrections

    SciTech Connect

    Borel, C.C.; Gerstl, S.A.W.

    1996-09-01

    In this paper the authors discuss two uses of BRDFs in remote sensing: (1) in determining the clear sky top of the atmosphere (TOA) albedo, (2) in quantifying the effect of the BRDF on the adjacency point-spread function and on atmospheric corrections. The TOA spectral albedo is an important parameter retrieved by the Multi-angle Imaging Spectro-Radiometer (MISR). Its accuracy depends mainly on how well one can model the surface BRDF for many different situations. The authors present results from an algorithm which matches several semi-empirical functions to the nine MISR measured BRFs that are then numerically integrated to yield the clear sky TOA spectral albedo in four spectral channels. They show that absolute accuracies in the albedo of better than 1% are possible for the visible and better than 2% in the near infrared channels. Using a simplified extensive radiosity model, the authors show that the shape of the adjacency point-spread function (PSF) depends on the underlying surface BRDFs. The adjacency point-spread function at a given offset (x,y) from the center pixel is given by the integral of transmission-weighted products of BRDF and scattering phase function along the line of sight.

  1. Reduplication facilitates early word segmentation.

    PubMed

    Ota, Mitsuhiko; Skarabela, Barbora

    2017-02-06

    This study explores the possibility that early word segmentation is aided by infants' tendency to segment words with repeated syllables ('reduplication'). Twenty-four nine-month-olds were familiarized with passages containing one novel reduplicated word and one novel non-reduplicated word. Their central fixation times in response to these as well as new reduplicated and non-reduplicated words introduced at test showed that familiarized reduplicated words were segmented better than familiarized non-reduplicated words. These results demonstrate that infants are predisposed to segment words with repeated phonological elements, and suggest that register-specific words in infant-directed speech may have evolved in response to this learning bias.

  2. Texture segmentation by genetic programming.

    PubMed

    Song, Andy; Ciesielski, Vic

    2008-01-01

    This paper describes a texture segmentation method using genetic programming (GP), which is one of the most powerful evolutionary computation algorithms. By choosing an appropriate representation texture, classifiers can be evolved without computing texture features. Due to the absence of time-consuming feature extraction, the evolved classifiers enable the development of the proposed texture segmentation algorithm. This GP based method can achieve a segmentation speed that is significantly higher than that of conventional methods. This method does not require a human expert to manually construct models for texture feature extraction. In an analysis of the evolved classifiers, it can be seen that these GP classifiers are not arbitrary. Certain textural regularities are captured by these classifiers to discriminate different textures. GP has been shown in this study as a feasible and a powerful approach for texture classification and segmentation, which are generally considered as complex vision tasks.

  3. Metrology of IXO Mirror Segments

    NASA Technical Reports Server (NTRS)

    Chan, Kai-Wing

    2011-01-01

    For future x-ray astrophysics mission that demands optics with large throughput and excellent angular resolution, many telescope concepts build around assembling thin mirror segments in a Wolter I geometry, such as that originally proposed for the International X-ray Observatory. The arc-second resolution requirement posts unique challenges not just for fabrication, mounting but also for metrology of these mirror segments. In this paper, we shall discuss the metrology of these segments using normal incidence metrological method with interferometers and null lenses. We present results of the calibration of the metrology systems we are currently using, discuss their accuracy and address the precision in measuring near-cylindrical mirror segments and the stability of the measurements.

  4. Morphing of Segmented Bimorph Mirrors

    NASA Astrophysics Data System (ADS)

    Rodrigues, Gonçalo; Bastaits, Renaud; Preumont, André

    2010-08-01

    Atmospheric turbulence compensation for the next generation of terrestrial telescopes (30-40 m diameter) will require deformable mirrors of increasing size and a number of actuators reaching several thousands. However, the mere extrapolation of existing designs leads to complicated and extremely expensive mirrors. This article discusses an alternative solution based on the use of segmented identical hexagonal bimorph mirrors. This allows to indefinitely increase the degree of correction while maintaining the first mechanical resonance at the level of a single segment, and shows an increase in price only proportional to the number of segments. Extensive simulations using random turbulent screens show that the segmentation produces only moderate reductions of the Strehl number, compared to a monolithic bimorph mirror with the same number of actuators (S = 0.86 instead of S = 0.89 in this study).

  5. An adaptive grid for graph-based segmentation in retinal OCT

    PubMed Central

    Lang, Andrew; Carass, Aaron; Calabresi, Peter A.; Ying, Howard S.; Prince, Jerry L.

    2016-01-01

    Graph-based methods for retinal layer segmentation have proven to be popular due to their efficiency and accuracy. These methods build a graph with nodes at each voxel location and use edges connecting nodes to encode the hard constraints of each layer’s thickness and smoothness. In this work, we explore deforming the regular voxel grid to allow adjacent vertices in the graph to more closely follow the natural curvature of the retina. This deformed grid is constructed by fixing node locations based on a regression model of each layer’s thickness relative to the overall retina thickness, thus we generate a subject specific grid. Graph vertices are not at voxel locations, which allows for control over the resolution that the graph represents. By incorporating soft constraints between adjacent nodes, segmentation on this grid will favor smoothly varying surfaces consistent with the shape of the retina. Our final segmentation method then follows our previous work. Boundary probabilities are estimated using a random forest classifier followed by an optimal graph search algorithm on the new adaptive grid to produce a final segmentation. Our method is shown to produce a more consistent segmentation with an overall accuracy of 3.38 μm across all boundaries. PMID:27773959

  6. Characterization of Drosophila larval crawling at the level of organism, segment, and somatic body wall musculature.

    PubMed

    Heckscher, Ellie S; Lockery, Shawn R; Doe, Chris Q

    2012-09-05

    Understanding rhythmic behavior at the developmental and genetic levels has important implications for neurobiology, medicine, evolution, and robotics. We studied rhythmic behavior--larval crawling--in the genetically and developmentally tractable organism, Drosophila melanogaster. We used narrow-diameter channels to constrain behavior to simple, rhythmic crawling. We quantified crawling at the organism, segment, and muscle levels. We showed that Drosophila larval crawling is made up of a series of periodic strides. Each stride consists of two phases. First, while most abdominal segments remain planted on the substrate, the head, tail, and gut translocate; this "visceral pistoning" moves the center of mass. The movement of the center of mass is likely powered by muscle contractions in the head and tail. Second, the head and tail anchor while a body wall wave moves each abdominal segment in the direction of the crawl. These two phases can be observed occurring independently in embryonic stages before becoming coordinated at hatching. During forward crawls, abdominal body wall movements are powered by simultaneous contraction of dorsal and ventral muscle groups, which occur concurrently with contraction of lateral muscles of the adjacent posterior segment. During reverse crawls, abdominal body wall movements are powered by phase-shifted contractions of dorsal and ventral muscles; and ventral muscle contractions occur concurrently with contraction of lateral muscles in the adjacent anterior segment. This work lays a foundation for use of Drosophila larva as a model system for studying the genetics and development of rhythmic behavior.

  7. In vivo and in vitro heterogeneity of segment length changes in the semimembranosus muscle of the toad.

    PubMed

    Ahn, A N; Monti, R J; Biewener, A A

    2003-06-15

    Many studies examine sarcomere dynamics in single fibres or length-tension dynamics in whole muscles in vivo or in vitro, but few studies link the various levels of organisation. To relate data addressing in vitro muscle segment behaviour with in vivo whole muscle behaviour during locomotion, we measured in vivo strain patterns of muscle segments using three sonomicrometry crystals implanted along a fascicle of the semimembranosus muscle in the American toad (Bufo americanus; n = 6) during hopping. The centre crystal emitted an ultrasonic signal, while the outer crystals received the signal allowing the instantaneous measurement of lengths from two adjacent muscle segments. On the first day, we recorded from the central and distal segments. On the second day of recordings, the most distal crystal was moved to a proximal position to record from a proximal segment and the same central segment. When the toads hopped a distance of two body lengths, the proximal and central segments strained -15.1 +/- 6.1 and -14.0 +/- 4.9 % (i.e. shortening), respectively. Strain of the distal segment, however, was significantly lower and more variable in pattern, often lengthening before shortening during a hop. From rest length, the distal segment initially lengthened by 2.6 +/- 2.0 % before shortening by 6.5 +/- 3.2 % at the same hop distance. Under in vitro conditions, the central segment always shortened more than the distal segment, except when passively cycled, during which the segments strained similarly. When the whole muscle was cycled sinusoidally and stimulated phasically in vitro, the two adjacent segments strained in opposite directions over much (up to 34 %) of the cycle. These differences in strain amplitude and direction imply that two adjacent segments can not only produce and/or absorb varying amounts of mechanical energy, but can also operate on different regions of their force-length and force-velocity relationships when activated by the same neural signal

  8. Neural network for image segmentation

    NASA Astrophysics Data System (ADS)

    Skourikhine, Alexei N.; Prasad, Lakshman; Schlei, Bernd R.

    2000-10-01

    Image analysis is an important requirement of many artificial intelligence systems. Though great effort has been devoted to inventing efficient algorithms for image analysis, there is still much work to be done. It is natural to turn to mammalian vision systems for guidance because they are the best known performers of visual tasks. The pulse- coupled neural network (PCNN) model of the cat visual cortex has proven to have interesting properties for image processing. This article describes the PCNN application to the processing of images of heterogeneous materials; specifically PCNN is applied to image denoising and image segmentation. Our results show that PCNNs do well at segmentation if we perform image smoothing prior to segmentation. We use PCNN for obth smoothing and segmentation. Combining smoothing and segmentation enable us to eliminate PCNN sensitivity to the setting of the various PCNN parameters whose optimal selection can be difficult and can vary even for the same problem. This approach makes image processing based on PCNN more automatic in our application and also results in better segmentation.

  9. The Envisat-1 ground segment

    NASA Astrophysics Data System (ADS)

    Harris, Ray; Ashton, Martin

    1995-03-01

    The European Space Agency (ESA) Earth Remote Sensing Satellite (ERS-1 and ERS-2) missions will be followed by the Polar Orbit Earth Mission (POEM) program. The first of the POEM missions will be Envisat-1. ESA has completed the design phase of the ground segment. This paper presents the main elements of that design. The main part of this paper is an overview of the Payload Data Segment (PDS) which is the core of the Envisat-1 ground segment, followed by two further sections which describe in more detail the facilities to be offered by the PDS for archiving and for user servcies. A further section describes some future issues for ground segment development. Logica was the prime contractor of a team of 18 companies which undertook the ESA financed architectural design study of the Envisat-1 ground segment. The outputs of the study included detailed specifications of the components that will acquire, process, archive and disseminate the payload data, together with the functional designs of the flight operations and user data segments.

  10. Medical image segmentation by MDP model

    NASA Astrophysics Data System (ADS)

    Lu, Yisu; Chen, Wufan

    2011-11-01

    MDP (Dirichlet Process Mixtures) model is applied to segment medical images in this paper. Segmentation can been automatically done without initializing segmentation class numbers. The MDP model segmentation algorithm is used to segment natural images and MR (Magnetic Resonance) images in the paper. To demonstrate the accuracy of the MDP model segmentation algorithm, many compared experiments, such as EM (Expectation Maximization) image segmentation algorithm, K-means image segmentation algorithm and MRF (Markov Field) image segmentation algorithm, have been done to segment medical MR images. All the methods are also analyzed quantitatively by using DSC (Dice Similarity Coefficients). The experiments results show that DSC of MDP model segmentation algorithm of all slices exceed 90%, which show that the proposed method is robust and accurate.

  11. Communicative functions integrate segments in prosodies and prosodies in segments.

    PubMed

    Kohler, Klaus J

    2011-01-01

    This paper takes a new look at the traditionally established divide between sounds and prosodies, viewing it as a useful heuristics in language descriptions that focus on the segmental make- up of words. It pleads for a new approach that bridges this reified compartmentalization of speech in a more global communicative perspective. Data are presented from a German perception experiment in the framework of the Semantic Differential that shows interdependence of f0 contours and the spectral characteristics of a following fricative segment, for the expression of semantic functions along the scales questioning - asserting, excited - calm, forceful - not forceful, contrary - agreeable. The results lead to the conclusion that segments shape prosodies and are shaped by them in varying ways in the coding of semantic functions. This implies that the analysis of sentence prosodies needs to integrate the manifestation of segments, just as the analysis of segments needs to consider their prosodic embedding. In communicative interaction, speakers set broad prosodic time windows of varying sizes, and listeners respond to them. So, future phonetic research needs to concentrate on speech analysis in such windows.

  12. 3D Materials image segmentation by 2D propagation: a graph-cut approach considering homomorphism.

    PubMed

    Waggoner, Jarrell; Zhou, Youjie; Simmons, Jeff; De Graef, Marc; Wang, Song

    2013-12-01

    Segmentation propagation, similar to tracking, is the problem of transferring a segmentation of an image to a neighboring image in a sequence. This problem is of particular importance to materials science, where the accurate segmentation of a series of 2D serial-sectioned images of multiple, contiguous 3D structures has important applications. Such structures may have distinct shape, appearance, and topology, which can be considered to improve segmentation accuracy. For example, some materials images may have structures with a specific shape or appearance in each serial section slice, which only changes minimally from slice to slice, and some materials may exhibit specific inter-structure topology that constrains their neighboring relations. Some of these properties have been individually incorporated to segment specific materials images in prior work. In this paper, we develop a propagation framework for materials image segmentation where each propagation is formulated as an optimal labeling problem that can be efficiently solved using the graph-cut algorithm. Our framework makes three key contributions: 1) a homomorphic propagation approach, which considers the consistency of region adjacency in the propagation; 2) incorporation of shape and appearance consistency in the propagation; and 3) a local non-homomorphism strategy to handle newly appearing and disappearing substructures during this propagation. To show the effectiveness of our framework, we conduct experiments on various 3D materials images, and compare the performance against several existing image segmentation methods.

  13. Segmentation of whole cells and cell nuclei from 3-D optical microscope images using dynamic programming.

    PubMed

    McCullough, D P; Gudla, P R; Harris, B S; Collins, J A; Meaburn, K J; Nakaya, M A; Yamaguchi, T P; Misteli, T; Lockett, S J

    2008-05-01

    Communications between cells in large part drive tissue development and function, as well as disease-related processes such as tumorigenesis. Understanding the mechanistic bases of these processes necessitates quantifying specific molecules in adjacent cells or cell nuclei of intact tissue. However, a major restriction on such analyses is the lack of an efficient method that correctly segments each object (cell or nucleus) from 3-D images of an intact tissue specimen. We report a highly reliable and accurate semi-automatic algorithmic method for segmenting fluorescence-labeled cells or nuclei from 3-D tissue images. Segmentation begins with semi-automatic, 2-D object delineation in a user-selected plane, using dynamic programming (DP) to locate the border with an accumulated intensity per unit length greater that any other possible border around the same object. Then the two surfaces of the object in planes above and below the selected plane are found using an algorithm that combines DP and combinatorial searching. Following segmentation, any perceived errors can be interactively corrected. Segmentation accuracy is not significantly affected by intermittent labeling of object surfaces, diffuse surfaces, or spurious signals away from surfaces. The unique strength of the segmentation method was demonstrated on a variety of biological tissue samples where all cells, including irregularly shaped cells, were accurately segmented based on visual inspection.

  14. Is Preventative Long-Segment Surgery for Multi-Level Spondylolysis Necessary? A Finite Element Analysis Study

    PubMed Central

    Zhong, Dongyan; Xu, Hao; Wang, Lan; Yu, Jia; Luo, Zongping

    2016-01-01

    Objective For multi-level spondylolysis patients, surgeons commonly choose to fix all the segments with pars interarticularis defect even those without slippage and not responsible for clinical symptoms. In this study, we tried to study the necessity of the preventative long-segment surgery for the defected segment without slippage in treatment of multi-level spondylolysis patients from a biomechanical perspective. Method We established a bi-level spondylolysis model with pars defects at L4 and L5 segments, and simulated posterior lumbar interbody fusion (PLIF) and pedicle screw fixation at L5-S1 level. Then we compared the biomechanical changes at L4 segment before and after surgery in neutral, flexion, extension, lateral bending and axial rotation position. Results The stress on L4 pars interarticularis was very similar before and after surgery, and reached the highest in axial rotation. The L3-L4 intradiscal pressure was almost the same, while L4-L5 intradiscal pressure changed a little in lateral bending (increase from 1.993 to 2.160 MPa) and axial rotation (decrease from 1.639 to 1.307 MPa) after surgery. The PLIF surgery caused a little increase of range of motion at adjacent L4-L5 and L3-L4 levels, but the change is very tiny (1 degree). Conclusion The PLIF surgery will not cause significant biomechanical change at adjacent segment with pars defect in multi-level spondylolysis. On the contrary, excessive long-segment surgery will damage surrounding soft tissues which are important for maintaining the stability of spine. So a preventative long-segment surgery is not necessary for multi-level spondylolysis as long as there are no soft tissue degeneration signs at adjacent level. PMID:26918333

  15. Nicotinic systems in central nervous systems disease: degenerative disorders and beyond.

    PubMed

    Newhouse, P A; Kelton, M

    2000-03-01

    Advances in the understanding of the structure, function, and distribution of central nervous system (CNS) nicotinic receptors has provided the impetus for new studies examining the role(s) that these receptors and associated processes may play in CNS functions. Further motivation has come from the realization that such receptors are changed in degenerative neurologic diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Ongoing investigations of the molecular substructure of CNS nicotinic receptors and their pharmacology have begun to open up new possibilities for novel CNS therapeutics with nicotinic agents. Exploiting these possibilities will require understanding of the role(s) that these receptor systems play in human cognitive, behavioral, motor, and sensory functioning. Clues from careful studies of human cognition and behavior are beginning to emerge and will provide direction for studies of potentially therapeutic novel nicotinic agents. Modulation of these receptors with the ultimate goal of producing therapeutic benefits is the goal of these investigations and drug development. This paper will review studies from our laboratory and others that point to the importance of CNS nicotinic mechanisms in normal human cognitive and behavioral functioning as well as their role in disease states. In addition, this paper will examine potential clinical applications of nicotine and/or nicotinic agonists in a variety of CNS disorders with particular emphasis on structural brain disease including: movement disorders such as Parkinson's disease and Tourette's syndrome, cognitive/behavioral disorders such as Alzheimer's disease, attention deficit/hyperactivity disorder, and schizophrenia, and other more speculative applications. Important results from early therapeutic studies of nicotine and/or nicotinic agonists in these disease states are presented. For example, recent studies with nicotine and novel nicotinic agonists such as ABT-418 by our group

  16. Outcome Variation Across Centers After Surgery for Lumbar Stenosis and Degenerative Spondylolisthesis

    PubMed Central

    Desai, Atman; Bekelis, Kimon; Ball, Perry A.; Lurie, Jon; Mirza, Sohail K.; Tosteson, Tor D.; Zhao, Wenyan; Weinstein, James N.

    2014-01-01

    Study Design Retrospective review of a prospectively collected database. Objective To examine whether short- and long-term outcomes after surgery for lumbar stenosis (SPS) and degenerative spondylolisthesis (DS) vary across centers. Summary of Background Data Surgery has been shown to be of benefit for both SPS and DS. For both conditions, surgery often consists of laminectomy with or without fusion. Potential differences in outcomes of these overlapping procedures across various surgical centers have not yet been investigated. Methods Spine patient outcomes research trial cohort participants with a confirmed diagnosis of SPS or DS undergoing surgery were followed from baseline at 6 weeks, 3, 6, and 12 months, and yearly thereafter, at 13 spine clinics in 11 US states. Baseline characteristics and short- and long-term outcomes were analyzed. Results A total of 793 patients underwent surgery. Significant differences were found between centers with regard to patient race, body mass index, treatment preference, neurological deficit, stenosis location, severity, and number of stenotic levels. Significant differences were also found in operative duration and blood loss, the incidence of durotomy, the length of hospital stay, and wound infection. When baseline differences were adjusted for, significant differences were still seen between centers in changes in patient functional outcome (SF-36 bodily pain and physical function, and Oswestry Disability Index) at 1 year after surgery. In addition, the cumulative adjusted change in the Oswestry Disability Index Score at 4 years significantly differed among centers, with SF-36 scores trending toward significance. Conclusion There is a broad and statistically significant variation in short- and long-term outcomes after surgery for SPS and DS across various academic centers, when statistically significant baseline differences are adjusted for. The findings suggest that the choice of center affects outcome after these procedures

  17. Autologous platelet gel for tissue regeneration in degenerative disorders of the knee

    PubMed Central

    Napolitano, Marcello; Matera, Saverio; Bossio, Marcello; Crescibene, Antonio; Costabile, Enrico; Almolla, Joan; Almolla, Hesham; Togo, Francesco; Giannuzzi, Casimiro; Guido, Giampiero

    2012-01-01

    Background The refinement of the use of platelet-derived growth factors that has occurred over the last decade has led to a broadening of the fields of use, in particular for new treatments in orthopaedics aimed at improving tissue regeneration. Materials and methods Twenty-seven patients, aged between 18 and 81 years, with a diagnosis of degenerative joint disease lasting for more than 1 year were treated. The patients were divided into two groups, one with arthritis of the knee, the other with degenerative cartilage disease of the knee. Both groups were treated with a therapeutic protocol consisting of a cycle of three infiltrations of platelet-rich plasma at weekly intervals. The extemporaneous preparation was made from a sample of about 8 mL of venous whole blood collected into a specific Fibrin Polymer 2 test-tube from RegenLab® and centrifuged before addition of calcium gluconate. During the initial pre-treatment evaluation, specific questionnaires were administered, the Numerical Rating Scale (NRS) for subjective measurement of pain and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC); these assessments were repeated 7 days after the end of the treatment and at 6 months during the follow-up. Results The parameters evaluated improved in both groups after treatment and there was a further improvement after 6 months of follow-up; furthermore, there was a substantial decrease in pain right after the first infiltration. Discussion The patients were treated on an out-patient basis by a specifically created multidisciplinary team comprising a transfusion specialist, an orthopaedist and a radiologist, who collaborate in a symbiotic manner. The out-patient protocol exploits the regenerative properties of platelet-rich plasma, which is a low cost treatment; in practice, a diagnostic-therapeutic programme of lower intensity, but of high technical and professional quality is created. The strategy also reduces both the number of hospital

  18. Method of joining a vane cavity insert to a nozzle segment of a gas turbine

    SciTech Connect

    Burdgick, Steven Sebastian

    2002-01-01

    An insert containing apertures for impingement cooling a nozzle vane of a nozzle segment in a gas turbine is inserted into one end of the vane. The leading end of the insert is positioned slightly past a rib adjacent the opposite end of the vane through which the insert is inserted. The end of the insert is formed or swaged into conformance with the inner margin of the rib. The insert is then brazed or welded to the rib.

  19. Clinical and radiographic features of hybrid surgery for the treatment of skip-level cervical degenerative disc disease: A minimum 24-month follow-up.

    PubMed

    Wu, Ting-Kui; Wang, Bei-Yu; Cheng, Ding; Rong, Xin; Lou, Ji-Gang; Hong, Ying; Liu, Hao

    2017-02-25

    We describe the radiographic changes of IS and investigate the safety and feasibility of hybrid surgery (HS) coupling cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) for the treatment of skip-level cervical degenerative disc disease (CDDD). Twenty-seven patients who received HS were retrospectively reviewed. Clinical evaluation based on the Japanese Orthopedic Association (JOA) and Neck Disability Index (NDI) and Visual Analog Scale (VAS) scores. Radiographic parameters included cervical alignment (CA), functional spine unite (FSU) angle of intermediated segment (IS), range of motion (ROM) and intervertebral disc height (IDH). Data regarding radiographic changes at IS were collected. The mean follow-up duration of 30.10months. Compared with preoperative value, JOA, NDI and VAS scores significantly improved after surgery (p<0.05). The CA was recovered significantly after surgery (p<0.05). There was no significant difference in the FSU angle and the IDH of IS between before and at 24months postoperatively (p>0.05). The ROM of IS significantly decreased at the first week after surgery (p<0.05), was similar to preoperative value at 3months postoperatively and significantly increased after 6months (p<0.05). Radiographic changes at IS were observed in 2 patients and Class II Heterotopic ossification (HO) was detected in 2 patients. HS is a safe and feasible alternative procedure for the treatment of skip-level CDDD. It preserved the IS intact and achieved satisfactory clinical and radiographic outcomes over a 24-month follow-up.

  20. Survey of roadside alien plants in Hawai`i Volcanoes National Park and adjacent residential areas 2001-2005

    USGS Publications Warehouse

    Bio, Keali'i F.; Pratt, Linda W.; Jacobi, James D.

    2012-01-01

    The sides of all paved roads of Hawai`i Volcanoes National Park (HAVO) were surveyed on foot in 2001 to 2005, and the roadside presence of 240 target invasive and potentially invasive alien plant species was recorded in mile-long increments. Buffer zones 5–10 miles (8–16 km) long along Highway 11 on either side of the Kīlauea and Kahuku Units of the park, as well as Wright Road that passed by the disjunct `Ōla`a Tract Unit, were included in the survey. Highway 11 is the primary road through the park and a major island thoroughfare. Three residential subdivisions adjacent to the park were similarly surveyed in 0.5–1 mile (0.8–1.6 km) intervals in 2003, and data were analyzed separately. Two roads to the east and northeast were also surveyed, but data from these disjunct areas were analyzed separately from park roads. In total, 174 of the target alien species were observed along HAVO roads and buffers, exclusive of residential areas, and the mean number of target aliens per mile surveyed was 20.6. Highway 11 and its buffer zones had the highest mean number of target alien plants per mile (26.7) of all park roads, and the Mauna Loa Strip Road had the lowest mean (11.7). Segments of Highway 11 adjacent to HAVO and Wright Road next to `Ōla`a Tract had mean numbers of target alien per mile (24–47) higher than those of any internal road. Alien plant frequencies were summarized for each road in HAVO. Fifteen new records of vascular plants for HAVO were observed and collected along park roads. An additional 28 alien plant species not known from HAVO were observed along the buffer segments of Highway 11 adjacent to the park. Within the adjacent residential subdivisions, 65 target alien plant species were sighted along roadsides. At least 15 potentially invasive species not currently found within HAVO were observed along residential roads, and several other species found there have been previously eliminated from the park or controlled to remnant populations