Sample records for vacuum disc herniation

  1. Herniated Lumbar Disc

    MedlinePLUS

    ... effective as a cushion. This may cause a displacement of the disc’s center (called a herniated or ruptured disc) through a crack in the outer layer. Most disc herniations occur in the bottom two discs of the lumbar spine, at and just below the waist. A herniated ...

  2. Lumbar Disc Herniation in Adolescence

    Microsoft Academic Search

    Serdar Ozgen; Deniz Konya; O. Zafer Toktas; Adnan Dagcinar; M. Memet Ozek

    2007-01-01

    Lumbar disc herniation very rarely occurs in adolescence. The aim of this study was to assess the radiological, clinical and surgical features and case outcomes for adolescents with lumbar disc herniation, and to compare with adult cases. The cases of 17 adolescents (7 girls and 10 boys, age range 13–17 years) who were surgically treated for lumbar disc herniation in

  3. Herniated lumbar disc

    PubMed Central

    2009-01-01

    Introduction Herniated lumbar disc is a displacement of disc material (nucleus pulposus or annulus fibrosis) beyond the intervertebral disc space. The highest prevalence is among people aged 30-50 years, with a male to female ratio of 2:1. There is little evidence to suggest that drug treatments are effective in treating herniated disc. Methods and outcomes We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of drug treatments, non-drug treatments, and surgery for herniated lumbar disc? We searched: Medline, Embase, The Cochrane Library, and other important databases up to July 2008 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). Results We found 49 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. Conclusions In this systematic review, we present information relating to the effectiveness and safety of the following interventions: acupuncture, advice to stay active, analgesics, antidepressants, bed rest, corticosteroids (epidural injections), cytokine inhibitors (infliximab), discectomy (automated percutaneous, laser, microdisectomy, standard), exercise therapy, heat, ice, massage, muscle relaxants, non-steroidal anti-inflammatory drugs (NSAIDs), percutaneous disc decompression, spinal manipulation, and traction. PMID:19445754

  4. Radicular interdural lumbar disc herniation

    Microsoft Academic Search

    Ali Akhaddar; Omar Boulahroud; Abad Elasri; Brahim Elmostarchid; Mohammed Boucetta

    2010-01-01

    Intraradicular lumbar disc herniation is a rare complication of disc disease that is generally diagnosed only during surgery.\\u000a The mechanism for herniated disc penetration into the intradural space is not known with certainty, but adhesion between the\\u000a radicular dura and the posterior longitudinal ligament was suggested as the most important condition. The authors report the\\u000a first case of an intraradicular

  5. Herniated Lumbar Disc and Lumbar Radiculopathy

    Microsoft Academic Search

    Parviz Kambin

    The satisfactory outcome of arthroscopically and endoscopically assisted management of herniated lumbar discs hinges on accurate\\u000a diagnosis of the symptom-producing site. Although the mean age of onset of symptoms of disc herniation is around 35 yr, disc\\u000a herniations are occasionally observed in populations older than 60 or younger than 20 yr of age. In younger children, combined\\u000a slippage of the

  6. Endoscopic Discectomy for Extraforaminal Lumbar Disc Herniation

    Microsoft Academic Search

    Yuichi Takano; Nobuhiro Yuasa

    The microendoscopic discectomy (MED) technique has been one of the promising surgeries for lumbar disc herniation in the last few years. The purpose of this study is to report the feasibility of a minimally invasive technique for extraforaminal lumbar disc herniation. Ten patients with extraforaminal lumbar disc herniation (one at L3-4, four at L4-5, and five at L5-S1) underwent MED

  7. Migrated herniated disc mimicking a neoplasm

    Microsoft Academic Search

    Benjamin Hoch; George Hermann

    2010-01-01

    Disc sequestration is defined as migration of a herniated disc fragment into the epidural space such that it is completely\\u000a separated from the parent disc. We report a case of a migrated herniated disc that was initially pathologically diagnosed\\u000a as a cartilage neoplasm. In addition to confounding morphological features, this interpretation may have been influenced by\\u000a an initial radiological interpretation

  8. Contemporary management of symptomatic lumbar disc herniations.

    PubMed

    Jegede, Kolawole A; Ndu, Anthony; Grauer, Jonathan N

    2010-04-01

    Lumbar disc herniations are common clinical entities that may cause lumbar-related symptoms. The spectrum of treatment options is geared toward a patient's clinical presentation and ranges from nothing to surgical intervention. Many lumbar disc herniations cause no significant symptoms. In studies of asymptomatic individuals who have never experienced lumbar-related symptoms, 30% have been reported to have major abnormality on magnetic resonance imaging. The mainstay of treatment of patients with symptomatic disc herniations is accepted to be nonoperative (as long as there are no acute or progressive neurologic deficits); this includes medications, physical therapy, and potentially lumbar injection. For patients with symptomatic disc herniations who fail to respond appropriately to conservative measures, surgical intervention may be considered. For this population, lumbar discectomy is considered to be a good option. PMID:20399360

  9. Herniation of the upper lumbar discs

    Microsoft Academic Search

    E. Pásztor; I. Szarvas

    1981-01-01

    Summary On the basis of investigations involving 134 patients operated on at the National Institute of Neurosurgery, Budapest, the authors point out that herniations of the intervertebral discs at L 1\\/2, L 2\\/3, L 3\\/4 levels are characterized by more severe neurological changes. Paresis and autonomic disorders occur much more frequently than in lower lumbar disc herniations: paresis was found

  10. Percutaneous Treatment of Intervertebral Disc Herniation

    Microsoft Academic Search

    Xavier Buy; Afshin Gangi; Stéphane Guth; Ali Guermazi

    \\u000a Disc herniation is defined as rupture of the fibrocartilagenous annulus fibrosus that surrounds the intervertebral disc, associated\\u000a with the release of the central gelatinous nucleus pulposus. Most herniations take place in the lumbar area of the spine.\\u000a They occur more frequently in middle aged and older men, especially those involved in strenuous physical activity. They cause\\u000a physical disability with significant

  11. Cranial Neuropathy due to Intradural Disc Herniation

    PubMed Central

    Rapoport, Benjamin I.; Hartl, Roger; Schwartz, Theodore H.

    2014-01-01

    Background and Importance Herniated intervertebral disc fragments rarely penetrate the thecal sac, and intracranial hypotension attributable to such penetrating fragments is even more unusual. We describe the first reported case of a cranial neuropathy due to intradural herniation of a disc fragment, in which intracranial hypotension from a resulting cerebrospinal fluid leak caused bilateral abducens palsies. Clinical Presentation A 45-year-old man presented with a positional headache after having experienced a “popping” sensation in his back while lifting a heavy object. He also complained of blurred vision and was noted to have lateral gaze palsies bilaterally. Magnetic resonance imaging (MRI) of the brain revealed bilateral subdural collections, abnormal pachymeningeal enhancement, and cerebellar tonsillar herniation, suggesting intracranial hypotension. T2-weighted MRI of the spine revealed extrusion of the T12-L1 disc and suggested the presence of a disc fragment in the intradural space, displacing the caudal nerve roots. A myelogram demonstrated a filling defect extending into the subarachnoid space adjacent to the disc herniation, consistent with a free disc fragment in the intradural space. A diagnosis of intracranial hypotension due to a cerebrospinal fluid leak resulting from an intradural herniated disc was made. The diagnosis was confirmed intraoperatively. Conclusion Surgical removal of the herniated disc fragment and repair of the dural defect resulted in complete resolution of the cranial neuropathy. This rare etiology of a cranial neuropathy, arising from pathology in the thoracolumbar spine, illustrates the clinical teaching that the sixth cranial nerves are highly sensitive to deformation induced by intracranial hypotension. PMID:24535263

  12. Recurrent disc herniation in a man with ankylosing spondylitis.

    PubMed

    Stenback, B A; Reigo, T

    1994-01-01

    Disc herniation in patients with Bechterew disease is rare; even rarer are recurrent disc herniations, a condition which we have not found described before. The patient was operated on with an excellent result. PMID:7866832

  13. Lumbar disc herniation in patients with developmental spinal stenosis

    Microsoft Academic Search

    L. Y. Dai; B. Ni; L. S. Jia; H. K. Liu

    1996-01-01

    Lumbar spinal stenosis and lumbar disc herniation are usually regarded as two pathogenetically different conditions, but in the literature lumbar disc herniation in patients with developmental spinal stenosis has been rarely documented. In a clinical retrospective study, 42 lumbar disc herniations with developmental spinal stenosis were reported and analyzed. Discectomy was performed after laminotomy. The patients were followed-up for an

  14. Surgical approaches to thoracic disc herniations

    Microsoft Academic Search

    M. El-Kalliny; J. M. Tew; H. van Loveren; S. Dunsker

    1991-01-01

    Summary Early diagnosis of thoracic disc herniations has become more common with the advent of spinal magnetic resonance imaging (MRI). This early diagnosis combined with choosing the optimal surgical approach, to ensure adequate decompression without excessive cord and root manipulation, will achieve the optimum results. It is now clear that more lateral and anterior approaches to the thoracic spine are

  15. Gd-DTPA-enhanced MR in thoracic disc herniations

    Microsoft Academic Search

    P. M. Parizel; G. Rodesch; D. Balériaux; D. Zegers de Beyl; J. D'Haens; J. Noterman; C. Segebarth

    1989-01-01

    The Gd-DTPA-enhanced magnetic resonance findings in two patients with herniated thoracic intervertebral discs are reported. The first patient was a 56-year-old woman with a small subligamentous T6-7 disc herniation, slightly lateralized to the right. The second patient was a 51-year-old man with a central and right posterolateral disc herniation, including a large calcified fragment, at the T8-9 level. The nonenhanced

  16. Extraforaminal lumbar disc herniations: CT demonstration of Sharpey's fibers avulsion

    Microsoft Academic Search

    J.-F. Bonneville; M. Runge; F. Cattin; P. Potelon; Y.-S. Tang

    1989-01-01

    Forty-seven extraforaminal lumbar disc herniations (EFLDH) accounting for 7% of all lumbar disc herniations encountered during the same period of time were reviewed. L3–L4 or L4–L5 disc was involved in 89% of the cases giving rise to a L3 or L4 nerve root compression. An abnormal motion of lateral bending with rotation of the trunk was found retrospectively in 60%

  17. Percutaneous cervical nucleoplasty in the treatment of cervical disc herniation

    Microsoft Academic Search

    Jian Li; Deng-lu Yan; Zai-Heng Zhang

    2008-01-01

    Percutaneous disc decompression procedures have been performed in the past. Various percutaneous techniques such as percutaneous\\u000a discectomy, laser discectomy, and nucleoplasty have been successful. Our prospective study was directly to evaluate the results\\u000a of percutaneous cervical nucleoplasty (PCN) surgery for cervical disc herniation, and illustrate the effectiveness of PCN\\u000a in symptomatic patients who had cervical herniated discs. From July of

  18. Sacral Perineural Cyst Accompanying Disc Herniation

    PubMed Central

    Ju, Chang Il; Shin, Ho; Kim, Hyeun Sung

    2009-01-01

    Although most of sacral perineural cysts are asymptomatic, some may produce symptoms. Specific radicular pain may be due to distortion, compression, or stretching of nerve root by a space occupying cyst. We report a rare case of S1 radiculopathy caused by sacral perineural cyst accompanying disc herniation. The patient underwent a microscopic discectomy at L5-S1 level. However, the patient's symptoms did not improved. The hypesthesia persisted, as did the right leg pain. Cyst-subarachnoid shunt was set to decompress nerve root and to equalize the cerebrospinal fluid pressure between the cephalad thecal sac and cyst. Immediately after surgery, the patient had no leg pain. After 6 months, the patient still remained free of leg pain. PMID:19352483

  19. [Lumbar disc herniation--diagnosis and treatment].

    PubMed

    Corniola, M-V; Tessitore, E; Schaller, K; Gautschi, O P

    2014-12-10

    A lumbar disc herniation (LDH) is a condition frequently encountered in primary care medicine. It may give rise to a compression of one or more nerve roots, which can lead to a nerve root irritation, a so-called radiculopathy, with or without a sensorimotor deficit. The majority of LDHs can be supported by means of a conservative treatment consisting of physical therapy, ergotherapy, analgetics, anti-inflammatory therapy or corticosteroids, which may be eventually administered by infiltrations. If a clinico-radiological correlation is present and moderate neurological deficit appears suddenly, if it is progressive under conservative treatment or if pain is poorly controlled by well-conducted conservative treatment performed during four to six months, surgery is then recommended. PMID:25632633

  20. A Symptomatic Spinal Extradural Arachnoid Cyst with Lumbar Disc Herniation

    PubMed Central

    Kadono, Yoshinori; Yuguchi, Takamichi; Ohnishi, Yu-ichiro; Iwatsuki, Koichi; Yoshimine, Toshiki

    2015-01-01

    Spinal epidural arachnoid cyst (EAC) is a rare, usually asymptomatic condition of unknown origin, which typically involves the lower thoracic spine. We report a case of posttraumatic symptomatic EAC with lumbar disc herniation. A 22-year-old man experienced back pain and sciatica after a traffic accident. Neurological examination revealed a right L5 radiculopathy. Magnetic resonance imaging demonstrated a cystic lesion at the L3 to L5 level and an L4-5 disc herniation; computed tomography myelography showed that the right L5 root was sandwiched between the cyst and the herniation. A dural defect was identified during surgery. The cyst was excised completely and the defect was repaired. A herniation was excised beside the dural sac. Histology showed that the cyst wall consisted of collagen and meningothelial cells. Postoperatively the symptoms resolved. Lumbar spinal EACs are rare; such cysts may arise from a congenital dural crack and grow gradually. The 6 cases of symptomatic lumbar EAC reported in the literature were not associated with disc herniation or trauma. In this case, the comorbid disc herniation was involved in symptom progression. Although many EACs are asymptomatic, comorbid spinal disorders such as disc herniation or trauma can result in symptom progression. PMID:25861499

  1. Walking analysis of rats subjected to experimental disc herniation

    Microsoft Academic Search

    K. Olmarker; M. Iwabuchi; K. Larsson; B. Rydevik

    1998-01-01

    In an attempt to evaluate whether experimental disc herniation can result in changes in walking pattern, presumably indicating\\u000a pain, four groups of rats – sham (n = 5), disc puncture (NP, n = 5), displacement of nerve root and ganglion (DIS, n = 5), and the combination of disc puncture and displacement (NP + DIS, n = 6) – were

  2. Surgical treatment of thoracic disc herniations via tailored posterior approaches

    Microsoft Academic Search

    Wolfgang Börm; U. Bäzner; R. W. König; T. Kretschmer; G. Antoniadis; J. Kandenwein

    We present clinical findings, radiological characteristics and surgical modalities of various posterior approaches to thoracic\\u000a disc herniations and report the clinical results in 27 consecutive patients. Within an 8-year period 27 consecutive patients\\u000a (17 female, 10 male) aged 30–83 years (mean 53 years.) were surgically treated for 28 symptomatic herniated thoracic discs\\u000a in our department. Six of these lesions (21%) were calcified.

  3. Sagittal spinal alignment in patients with lumbar disc herniation

    Microsoft Academic Search

    Kenji Endo; Hidekazu Suzuki; Hidetoshi Tanaka; Yupeng Kang; Kengo Yamamoto

    2010-01-01

    A retrospective cross-sectional study was designed to evaluate total sagittal spinal alignment in patients with lumbar disc\\u000a herniation (LDH) and healthy subjects. Abnormal sagittal spinal alignment could cause persistent low back pain in lumbar disease.\\u000a Previous studies analyzed sciatic scoliotic list in patients with lumbar disc herniation; but there is little or no information\\u000a on the relationship between sagittal alignment

  4. Outcome of symptomatic upper lumbar disc herniation.

    PubMed

    Awwal, M A; Ahsan, M K; Sakeb, N

    2014-10-01

    "Upper" lumbar disc herniations (LDH) are different from the "lower" and possess increased chance of neural compromise and cauda equina syndrome that necessitates operative management despite of contradictory surgical outcome. We underwent the study to assess the clinical and functional outcome of symptomatic upper LDH surgery from July 2003 to June 2012 in BSMMU, Dhaka, Bangladesh. The records of 123 patients (age range, 30-69 years), 56 men and 67 women (mean 52 years) having upper lumbar discectomy were reviewed. The surgical time, intra-operative blood loss, self evaluated back pain and thigh and/or groin pain status [using Visual Analogue Score (VAS)] and the disability status [using Oswestry disability (ODI) questionnaire] was analyzed. Radiological stability (using Posner's criteria), functional outcome [using Japanese Orthopaedic Association (JOA) Score] and overall outcome (using MacNab`s criteria), was calculated. Chi-squared test and z-test using SPSS revealed mean operative time and mean blood loss had no significant (p>0.05) difference. Pain, sensory, motor and reflex status as well as VAS, ODI and all the components of JOA questionnaire had significant (p<0.05) improvement. In spite of intra-operative complications in 20.32% cases, overall satisfactory outcome was achieved in 83.74% cases. The postoperative complications (08.13%) could be managed conservatively. However, carefully decided surgical alternatives resulted in satisfactory clinical and functional outcome in upper LDH surgery. PMID:25481595

  5. Extreme lateral lumbar disc herniation. Diagnosis and management.

    PubMed

    Perno, J R; Rossitch, E

    1993-05-01

    Extreme lateral disc herniation accounts for about 10% of lumbar disc ruptures and is more common in the elderly. Patients will frequently complain of pain in the groin and anterior thigh but little if any back pain. Because the L4 root is often involved, the physical exam often shows quadriceps weakness and a diminished patellar reflex. Other important signs include a negative Lasèque's sign and reproduction of pain with lateral bending of the back toward the involved extremity. Currently, CT or MRI are the diagnostic procedures of choice. The initial treatment for extreme lateral disc herniation is bed rest and NSAIDs with surgery if conservative therapy fails. Primary care physicians should consider extreme lateral disc herniation when they evaluate patients with low back and leg pain. PMID:8510777

  6. The Far Lateral Approach to Lumbar Disc Herniations

    Microsoft Academic Search

    F. Porchet; H. Fankhauser; N. DE TRIBOLET

    \\u000a The diagnosis of extreme lateral lumbar disc herniation (ELLDH) as a cause of lumbar radiculopathy was first described by\\u000a Abdullah in 1974 [1]. This discal pathology has been recognized for many years as an occasional cause of negative disc exploration and immediate\\u000a failure of classical disc surgery in sciatica [1,18, 24, 25, 29, 31, 30, 31, 33, 35, 41]. Only

  7. Spontaneous Intracranial Hypotension Secondary to Lumbar Disc Herniation

    PubMed Central

    Kim, Kyoung-Tae

    2010-01-01

    Spontaneous intracranial hypotension is often idiopathic. We report on a patient presenting with symptomatic intracranial hypotension and pain radiating to the right leg caused by a transdural lumbar disc herniation. Magnetic resonance (MR) imaging of the brain revealed classic signs of intracranial hypotension, and an additional spinal MR confirmed a lumbar transdural herniated disc as the cause. The patient was treated with a partial hemilaminectomy and discectomy. We were able to find the source of cerebrospinal fluid leak, and packed it with epidural glue and gelfoam. Postoperatively, the patient's headache and log radiating pain resolved and there was no neurological deficit. Thus, in this case, lumbar disc herniation may have been a cause of spontaneous intracranial hypotension. PMID:20157378

  8. Extraforaminal lumbar disc herniations: CT demonstration of Sharpey's fibers avulsion.

    PubMed

    Bonneville, J F; Runge, M; Cattin, F; Potelon, P; Tang, Y S

    1989-01-01

    Forty-seven extraforaminal lumbar disc herniations (EFLDH) accounting for 7% of all lumbar disc herniations encountered during the same period of time were reviewed. L3-L4 or L4-L5 disc was involved in 89% of the cases giving rise to a L3 or L4 nerve root compression. An abnormal motion of lateral bending with rotation of the trunk was found retrospectively in 60% of the patients. In 53% of all EFLDH a bony avulsion of the vertebral end-plate facing the herniation was demonstrated at the site of attachment of Sharpey's fibers. This study suggests that this previously undescribed bony change witnesses a special injury of the spine responsible for most EFLDH. PMID:2717008

  9. Intradural tumor and concomitant disc herniation of cervical spine

    PubMed Central

    Bapat, Mihir R; Rathi, Prasanna; Pawar, Uday; Chaudhary, Kshitij

    2011-01-01

    We report a rare patient of a simultaneous extradural and intradural compression of the cervical spinal cord due to co-existent intervertebral disc herniation and an intradural schwannoma at the same level. The intradural lesion was missed resulting in recurrence of myelopathy after a surprisingly complete functional recovery following anterior cervical discectomy. Retrospectively, it was noted that the initial cord swelling noticed was tumor being masked by the compression produced by the herniated disc. A contrast magnetic resonance imaging scan is important in differentiating intradural tumors of the spinal cord. A high index of suspicion is often successful in unmasking both the pathologies. PMID:21221228

  10. Intradural tumor and concomitant disc herniation of cervical spine.

    PubMed

    Bapat, Mihir R; Rathi, Prasanna; Pawar, Uday; Chaudhary, Kshitij

    2011-01-01

    We report a rare patient of a simultaneous extradural and intradural compression of the cervical spinal cord due to co-existent intervertebral disc herniation and an intradural schwannoma at the same level. The intradural lesion was missed resulting in recurrence of myelopathy after a surprisingly complete functional recovery following anterior cervical discectomy. Retrospectively, it was noted that the initial cord swelling noticed was tumor being masked by the compression produced by the herniated disc. A contrast magnetic resonance imaging scan is important in differentiating intradural tumors of the spinal cord. A high index of suspicion is often successful in unmasking both the pathologies. PMID:21221228

  11. Evaluation of Patients with Suspected Herniated Lumbar Discs with Radiculopathy

    Microsoft Academic Search

    Louis R. Caplan; M. J. Aminoff; H. Fankhauser; W. Brown

    1994-01-01

    Introduction Backache is a nearly ubiquitous complaint. Unfortunately, our supporting skeletal system was probably made for creatures that walk on all fours and does not suit human bipedal existence. Long periods of sitting and strenuous lifting, bending, and stretching are probably not good for the back. Degenerative disease of the back and disc herniations are extremely common. The report of

  12. Anterior discectomy without interbody fusion for cervical disc herniation

    Microsoft Academic Search

    V. Pointillart; A. Cernier; J. M. Vital; J. Senegas

    1995-01-01

    Between 1985 and 1990, 68 patients with cervical radiculopathy due to soft disc herniation were treated by anterior cervical discectomy without interbody fusion. Eleven patients were unavailable for follow-up examination. The mean follow-up was 23 months (range 12–54 months). Both clinical and radiographic follow-ups were done, and 92% of the patients was found to have excellent or good clinical results.

  13. Cauda equina compression syndrome in a child due to lumbar disc herniation

    Microsoft Academic Search

    Kadir Kotil; Mustafa Akçetin; Turgay Bilge

    2004-01-01

    IntroductionCauda equina syndrome with sphincter dysfunction is an uncommon and feared complication of lumbar disc herniation.Case reportLumbar disc disease in the pediatric age has been reported infrequently, but to the best of our knowledge, this is the first pediatric case of acute lumber disc herniation presenting with caudal compression.

  14. Percutaneous cervical nucleoplasty in the treatment of cervical disc herniation.

    PubMed

    Li, Jian; Yan, Deng-lu; Zhang, Zai-Heng

    2008-12-01

    Percutaneous disc decompression procedures have been performed in the past. Various percutaneous techniques such as percutaneous discectomy, laser discectomy, and nucleoplasty have been successful. Our prospective study was directly to evaluate the results of percutaneous cervical nucleoplasty (PCN) surgery for cervical disc herniation, and illustrate the effectiveness of PCN in symptomatic patients who had cervical herniated discs. From July of 2002 to June of 2005, 126 consecutive patients with contained cervical disc herniations have presented at the authors' clinic and treated by PCN. The patients' gender distribution for PCN was 65 male, 61 female. The age of patients ranged from 34 to 66 years (mean 51.9 +/- 10.2 years). The levels of involvement were 21 cases at C3-4, 30 cases at C4-5, 40 cases at C5-6, and 35 cases at C6-7. The clinical outcomes, pain reduction and the segment stability were all recorded during this study. A clinical outcome was quantified by the Macnab standard and using VAS. The angular displacement (AD) > or =11 degrees or horizontal displacement (HD) > or =3 mm was considered to be radiographically unstable. In the results of this study, puncture of the needle into the disc space was accurately performed under X-ray guidance in all cases. There was one case where the Perc-D Spine Wand had broken in the disc space during the procedure. The partial Perc-D Spine Wand, which had broken in the disc space could not be removed by the percutaneous cervical discectomy and thus remained there. There were no recurrent cases or complications in our series. Macnab standard results were excellent in 62 cases, good in 41 cases and fair in 23 cases. The rate of excellent and good was 83.73%. The VAS scores demonstrated statistically significant improvement in PCN at the 2-week, 1, 3, 6, and 12-month follow-up visits when compared to preoperational values (P < 0.01). There were no cases of instability following the PCN procedure. There was no significant difference in stability either preoperatively or postoperatively (P > 0.05). Our findings confirm that PCN for the treatment of cervical disc herniation results in a good outcome without any tampering of the stability of the cervical spine. Hence, PCN as a procedure is safe, minimally invasive, less traumatic, requiring less time with an excellent clinical outcome. PCN should be performed for those patients who fail conservative medical management including medication, physical therapy, behavioral management, psychotherapy, and who are unwilling to undergo a more invasive technique such as spinal surgery. PMID:18830638

  15. Combined Anterior Approach with Transcorporeal Herniotomy for a Huge Migrated Cervical Disc Herniation

    PubMed Central

    Ahn, Yong; Lee, Choon Dae; Lee, Sang-Ho

    2011-01-01

    The report describes the herniation of a huge migrated cervical disc, which was treated by a combined anterior approach. A 50-year-old man presented with radiculopathy and myelopathy. Radiological images revealed the herniation of a huge disc which had migrated superiorly from the C6-7 disc to the C5-6 disc. We tried to combine an anterior cervical discectomy and fusion (ACDF) and transcorporeal herniotomy to avoid corpectomy. Postoperatively, successful clinical and radiological results were obtained. It is therefore possible to remove a huge migrated herniated cervical disc completely by a combined ACDF and trancorporeal approach without corpectomy.

  16. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain

    Microsoft Academic Search

    Windt van der D. A. W. M; E. Simons; I. I. Riphagen; C. Ammendolia; A. P. Verhagen; M. Laslett; W. Devillé; R. A. Deyo; L. M. Bouter; Vet de H. C. W; B. Aertgeerts

    2010-01-01

    Background Low-back pain with leg pain (sciatica) may be caused by a herniated intervertebral disc exerting pressure on the nerve root. Most patients will respond to conservative treatment, but in carefully selected patients, surgical discectomy may provide faster relief of symptoms. Primary care clinicians use patient history and physical examination to evaluate the likelihood of disc herniation and select patients

  17. Physical examination for lumbar radiculopathy due to disc herniation in patients with low-back pain

    Microsoft Academic Search

    D. A. W. M. van der Windt; E. Simons; I. I. Riphagen; C. Ammendolia; A. P. Verhangen; M. Laslett; W. Devillé; R. A. Deyo; L. M. Bouter; H. C. W. de Vet; B. Aertgeerts

    2010-01-01

    Background: Low-back pain with leg pain (sciatica) may be caused by a herniated intervertebral disc exerting pressure on the nerve root. Most patients will respond to conservative treatment, but in carefully selected patients, surgical discectomy may provide faster relief of symptoms. Primary care clinicians use patient history and physical examination to evaluate the likelihood of disc herniation and select patients

  18. The transdural approach for thoracic disc herniations: a technical note

    PubMed Central

    Moon, Sung-Jun; Jang, Jae-Won; Hur, Hyuk; Lee, Jae-Hyun; Kim, Soo-Han

    2010-01-01

    Surgery for thoracic disc herniations is still challenging, and the disc excision via a posterior laminectomy is considered risky. A variety of dorsolateral and ventral approaches have been developed. However, the lateral extracavitary and transthoracic approach require extensive surgical exposure. Therefore, we adopted a posterior transdural approach for direct visualization without entry into the thoracic cavity. Three cases that illustrate this procedure are reported here with the preoperative findings, radiological findings and surgical techniques used. After the laminectomy, at the involved level, the dorsal dura was opened with a longitudinal paramedian incision. The cerebrospinal fluid was drained to gain more operating space. After sectioning of the dentate ligaments, gentle retraction was applied to the spinal cord. Between the rootlets above and below, the ventral dural bulging was clearly observed. A small paramedian dural incision was made over the disc space and the protruded disc fragment was removed. Neurological symptoms were improved, and no surgery-related complication was encountered. The posterior transdural approach may offer an alternative surgical option for selected patients with thoracic paracentral soft discs, while limiting the morbidity associated with the exposure. PMID:20143105

  19. Posterior epidural migration of an extruded free fragment from a lumbar disc herniation

    Microsoft Academic Search

    Pietro Lisai; Carlo Doria; Leonardo Crissantu; Tomas Dore; Gabriele Spano; Carlo Fabbriciani

    2000-01-01

    The majority of symptomatic lumbar disc herniations are located in a posterolateral position with resultant nerve root compression.\\u000a Although caudal, rostral and lateral migrations of disc fragments are common, posterior epidural migration of an extruded\\u000a free fragment from a lumbar disc herniation is a rare occurrence and sometimes may cause a dural sac compression with cauda\\u000a equina syndrome. This retrospective

  20. Minimally invasive pars approach for foraminal disc herniation.

    PubMed

    Hitchon, Patrick W; Awe, Olatilewa O; Close, Liesl; Sukkarieh, Hamdi G

    2015-07-01

    We present a retrospective cohort study on the outcome of patients with foraminal disc herniations (FDH) treated with partial pars resections using minimally invasive surgery (MIS) through a tube. FDH present a challenge due to the more lateral trajectory needed for their excision and thereby more muscle dissection and possibly facet resection. Forty patients, 19 women and 21 men with a mean age±standard deviation of 58±12years, underwent MIS for FDH. Data on length of hospital stay, body mass index and outcomes were collected prospectively and reviewed retrospectively. Average length of stay following surgery was 1±1days. There was one wound infection and four unsatisfactory results. Using the Macnab score, good to excellent results were achieved in 89% of the patients. Based on these results, MIS surgery with partial pars resection is an attractive option in the treatment of FDH with low morbidity and short hospital stays. PMID:25882259

  1. Lumbar disc herniation in three patients with cystic fibrosis: a case series

    PubMed Central

    2011-01-01

    Introduction To date, lumbar disc herniation has not been reported in the context of cystic fibrosis even though back pain and musculoskeletal problems are very common in patients with cystic fibrosis. Case presentation We report on three patients with cystic fibrosis who experienced lumbar disc herniation in the course of their disease at ages 19 to 21 years (a 22-year-old Caucasian man, a 23-year-old Caucasian man, and a 21-year-old Caucasian woman). Our third patient eventually died because of her deteriorated pulmonary situation, which was influenced by the lumbar disc herniation as it was not possible for her to perform pulmonary drainage techniques properly because of the pain. Conclusions Lumbar disc herniation can lead to a vicious cycle for patients with cystic fibrosis as it may promote pulmonary infections. This report highlights the need to investigate patients correctly. PMID:21896180

  2. Spinal manipulation results in immediate H-reflex changes in patients with unilateral disc herniation

    Microsoft Academic Search

    Y. Floman; N. Liram; A. N. Gilai

    1997-01-01

    The aim of this clinical investigation was to determine whether the abnormal H-reflex complex present in patients with S 1 nerve root compression due to lumbosacral disc herniation is improved by single-session lumbar manipulation. Twenty-four patients with unilateral disc herniation at the L5-S1 level underwent spinal H-reflex electro-physiological evaluation. This was carried out before and after single-session lumbar manipulation in

  3. Foraminal and far lateral lumbar disc herniations: surgical alternatives and outcome measures

    Microsoft Academic Search

    NE Epstein

    2002-01-01

    Far lateral disc herniations constitute 7–12% of all disc herniations. They may be purely far lateral or extraforaminal in location, located beyond the pedicles, or may include intraforaminal and even intracanalicular components. Occurring predominantly at the L4–L5 and L3–L4 levels in almost equal numbers, they are occasionally noted at L5–S1. Clinical syndromes reflect compression of the superiorly exiting nerve root

  4. Foraminal and far lateral lumbar disc herniations: surgical alternatives and outcome measures

    Microsoft Academic Search

    NE Epstein

    Far lateral disc herniations constitute 7-12% of all disc herniations. They may be purely far lateral or extraforaminal in location, located beyond the pedicles, or may include intraforaminal and even intracanalicular components. Occurring predominantly at the L4- L5 and L3-L4 levels in almost equal numbers, they are occasionally noted at L5-S1. Clinical syndromes reflect compression of the superiorly exiting nerve

  5. Propriospinal Myoclonus Induced by a Herniated Lumbar Intervertebral Disc at a Young Age: A Case Report

    PubMed Central

    Song, Kwan Su; Kim, Chang Hyun; Lee, Ho Kook

    2011-01-01

    The cause of propriospinal myoclonus (PSM) is idiopathic. Cervical trauma, ischemic myelopathy secondary to a spinal dural arteriovenous fistula, syringomyelia, Lyme neuroborreliosis, human immunodeficiency virus central nervous system infection, and cervical disc herniation can be the cause of PSM, but lumbar herniated intervertebral disc (HIVD) induced PSM has not been reported. We describe a patient who presented with PSM induced by HIVD and was treated with an epidural steroid injection using a transforaminal approach.

  6. Spontaneous Remission of a Big Subligamentous Extruded Disc Herniation: Case Report and Review of the Literature

    PubMed Central

    ?brahimo?lu, Muhammet

    2015-01-01

    Spontaneous Regression of a Big Subligamentous Extruded Disc Herniation: Case Report And Review of The Literature The most efficient method for the treatment of lumbar disc herniation is still controversial. The most important aspect is the application of the suitable conservative or surgical treatment to the right patient at the right time. In lumbar disc herniation patients, one must not precipitate except for cases that require surgical indications as in cauda equina syndrome, evolutive motor deficit and persistence of pain in spite of the narcotics. However, the spontaneous regression mechanism has not been completely determined yet. The proposed hypotheses are; dehydration, retraction of the disc to the hernia in the annulus fibrosis, enzymatic catabolism and phagocytosis. In this study, the case of a patient with huge lumbar disc hernia regressing by itself has been presented and the potential mechanisms of disc regression have been discussed. PMID:25883664

  7. Unusual case of camptocormia triggered by lumbar-disc herniation.

    PubMed

    Duman, Iltekin; Baklaci, Korhan; Tan, Arif Kenan; Kalyon, Tunc Alp

    2008-04-01

    A 21-year-old male patient with low back pain and marked forward bending was presented. The exaggerated lumbar flexion was preventing him to stand in erect posture but disappeared while lying. The symptoms had begun after he had lifted a heavy object. Straight-leg-raising test could not be performed properly because of the exaggerated pain. The light-touch sense was decreased on L5 and S1 dermatomes. There was no loss of muscle strength. The deep-tendon reflexes were normal. Plain graph showed mild narrowing in the L4-5 and L5-S1 intervertebral spaces. Lumbar magnetic resonance imaging revealed disc protrusions in L4-5 and L5-S1 levels. During his stay in the department, the patient was given tizanidine and tramadol, and physical therapy was performed. A paravertebral intramuscular injection with lidocaine was applied. Moreover, the patient was referred to psychiatrist for evaluation regarding his medical history of conversive seizures and possible efforts for secondary gain. No response was obtained from all the treatments. The final diagnosis was camptocormia triggered by lumbar-disc herniation. He was applied supportive psychotherapy, psychoeducation regarding secondary gain, strong suggestions to improve posture, positive reinforcement, and behavioral therapy. His postural abnormality resolved and disappeared completely with mild pain. PMID:18087763

  8. Target radiofrequency combined with collagenase chemonucleolysis in the treatment of lumbar intervertebral disc herniation

    PubMed Central

    Zhang, Daying; Zhang, Yong; Wang, Zhijian; Zhang, Xuexue; Sheng, Mulan

    2015-01-01

    Both target radiofrequency thermocoagulation and collagenase chemonucleolysis are effective micro-invasive therapy means for lumbar intervertebral disc herniation. In order to analyze the clinical effects of target radiofrequency thermocoagulation combined with collagenase chemonucleolysis on lumbar intervertebral disc herniation, the contents of hydroxyproline and glycosaminoglycan were measured and the histological changes of nucleus pulposus was detected in the vitro experiments. Radiofrequency thermocoagulation reduced the hydrolyzation of herniated nucleus pulposus caused by collagenase, as well as the content of hydroxyproline and glycosaminoglycan. Furthermore, 236 patients with lumbar intervertebral disc herniation were treated by target radiofrequency thermocoagulation combined with collagenase chemonucleolysis. The efficiency was evaluated according to Macnab criteria, and the index of lumbar disc herniation (IDH) was compared pre-operation with 3 months post-operation. The post-operative good rate was 66.5% (157/236) at 2 weeks post-operation, and 88.1% (208/236) at 3 months post-operation. In the post-operative follow-up exam, 86.8% of the re-examined cases demonstrated smaller or ablated protrusion, with reduced IDH values from pre-operation, which was statistically significant. No serious complications were detected intra-operatively and post-operatively. In conclusion, target radiofrequency combined with collagenase chemonucleolysis was an effective and safe method for treatment of lumbar intervertebral disc herniation. PMID:25785026

  9. Hemilaminoplasty for the treatment of lumbar disc herniation

    PubMed Central

    Xinyu, Liu; Jianmin, Li; Liangtai, Gong

    2008-01-01

    The aim of this study was to evaluate the clinical outcome of the hemilaminoplasty technique for the treatment of lumbar disc herniation (LDH). Forty-three cases of single-level LDH underwent a discectomy and hemilaminoplasty procedure. The preoperative JOA score and VAS of lower back and leg pain were 10.4±1.3, 7.8±2.1, and 8.6±1.7, respectively. The Cobb angle of lumbar sagittal alignment was 10.1±2.0. Twenty-five patients who agreed to lumbar discectomy through fenestration were enrolled as the control group. The postoperative JOA score and VAS of low back and leg pain of the hemilaminoplasty group were 19.4±1.3, 1.4±0.4, and 2.1±0.5, respectively. The Cobb angle was 29.2±1.9 degrees. There was no epidural scar observed in any of the patients. The Cobb angle of the hemilaminoplasty group was higher than that of the control group (p?

  10. Hemilaminoplasty for the treatment of lumbar disc herniation.

    PubMed

    Xinyu, Liu; Yanping, Zheng; Jianmin, Li; Liangtai, Gong

    2009-10-01

    The aim of this study was to evaluate the clinical outcome of the hemilaminoplasty technique for the treatment of lumbar disc herniation (LDH). Forty-three cases of single-level LDH underwent a discectomy and hemilaminoplasty procedure. The preoperative JOA score and VAS of lower back and leg pain were 10.4+/-1.3, 7.8+/-2.1, and 8.6+/-1.7, respectively. The Cobb angle of lumbar sagittal alignment was 10.1+/-2.0. Twenty-five patients who agreed to lumbar discectomy through fenestration were enrolled as the control group. The postoperative JOA score and VAS of low back and leg pain of the hemilaminoplasty group were 19.4+/-1.3, 1.4+/-0.4, and 2.1+/-0.5, respectively. The Cobb angle was 29.2+/-1.9 degrees. There was no epidural scar observed in any of the patients. The Cobb angle of the hemilaminoplasty group was higher than that of the control group (p < 0.05), while the VAS was significantly lower (p < 0.05). Hemilaminoplasty is a useful method to improve clinical outcome, prevent epidural scar, and preserve the normal alignment of lumbar spine. PMID:18636258

  11. Role of interleukin-17 in chondrocytes of herniated intervertebral lumbar discs

    PubMed Central

    TIAN, PENG; LI, ZHI-JUN; FU, XIN; MA, XIN-LONG

    2015-01-01

    Lumbar disc herniation (LDH) is a common cause of lumbosacral radiculopathy. An autoimmune response to a herniated nucleus pulposus (NP) has been suggested to play an important role in the initiation of radiculopathy. Interleukin-17 (IL-17) is a cytokine associated with inflammation and autoimmunity. The presence of IL-17 has been studied in patients with LDH; however, extensive investigation into the expression of IL-17 in different disc pathologies of LDH has not yet been conducted. The aim of the present study was to investigate the role of neovascularization and hypertrophic chondrocytes in herniated intervertebral lumbar discs. Fifty-two intervertebral lumbar disc specimens were extracted from 46 patients with LDH and were subsequently classified as either contained or non-contained disc herniation (CDH and NCDH, respectively). The specimens were stained with hematoxylin and eosin or toluidine blue, or were immunostained with polyclonal antibodies to IL-17 using the streptavidin-peroxidase method. The neovascular tissue and staining results were graded to establish the histological differences between the two herniation types. The intervertebral discs (IVDs) obtained from patients with NCDH showed significantly more neovascularization and granulation tissue than the discs obtained from patients with CDH (P<0.05). Furthermore, hypertrophic chondrocytes were more abundant in the NCDH specimens than in the CDH specimens (P<0.05). Similarly, the number of IL-17-immunoreactive cells was significantly higher in the NCDH specimens than that in the CDH specimens (P<0.01). In conclusion, local inflammation and autoreactive immune activation may play an important role in the pathogenesis of LDH. These results also suggest a role of chondrocytes in the repair of herniated IVDs. PMID:26170916

  12. Massive lumbar disc herniation with complete dural sac stenosis

    PubMed Central

    Jeon, Chang-Hoon; Chung, Nam-Su; Son, Kwang-Hyun; Lee, Hyo-Sung

    2013-01-01

    Background: Large lumbar disc herniation (LDH) has been reported to have a greater tendency to resolve in clinical and pathomorphological evolutions. However, various definitions of large LDH have been used without validation, and the clinical symptoms of large LDH have not been fully elucidated. We conducted a retrospective analysis to determine the clinical characteristics and treatment outcome of massive LDH with complete dural sac stenosis Materials and Methods: We retrospectively reviewed 33 cases of LDH with complete dural sac stenosis on magnetic resonance imaging. Complete dural sac stenosis was defined as no recognizable rootlet and cerebrospinal fluid signal on T2-weighed axial MR images. The clinical outcome parameters included back pain, leg pain, Oswestry disability index (ODI), and neurological dysfunction. The paired t-test and Wilcoxon's signed rank test were used to compare serial changes in back pain, leg pain and neurological dysfunction. Results: Mean duration of followup was 66 months (range 24 - 108 months). There were 24 male and 9 female. The mean age was 37 years (range 20 - 53 years). At presentation, mean visual analogue scales for back pain and leg pain were 75.3 ± 19.1 (range 12 - 100) and 80.2 ± 14.6 (range 0 -100), respectively. Mean ODI was 67.1 ± 18.8 (range 26 - 88). Neurological dysfunction was found in 9 patients (27.3%), and the bowel/bladder dysfunction was found in 2 patients (3.1%). Conservative treatment was performed in 21 patients (63.6%) with satisfactory results. Seven patients underwent decompressive surgery, and 5 underwent posterolateral fusion. Conclusions: A massive LDH with complete dural sac stenosis was found to be associated with severe back and leg pain at presentation, however surgical treatment can be deferred unless significant neurological symptoms occur. PMID:23798754

  13. Effect of ligamenta flava hypertrophy on lumbar disc herniation with contralateral symptoms and signs: a clinical and morphometric study

    PubMed Central

    Yildizhan, Ahmet; Atar, Elmas K.; Yaycioglu, Soner; Gocmen-Mas, Nuket; Yazici, Canan

    2010-01-01

    Introduction The purpose of this study was to determine whether ligamentum flavum hypertrophy among disc herniated patients causes contralateral pain symptoms. For this reason we measured the thickness of the ligament in disc herniated patients with ipsilateral or contralateral symptoms. Material and methods Two hundred disc herniated patients with ipsilateral symptoms as group I were compared with five disc herniated patients with only contralateral symptoms as group II. Ligamenta flava thicknesses and spinal canal diameters of both groups were measured on magnetic resonance imaging (MRI) with a micro-caliper. Results Both groups underwent surgery only on the disc herniated side. The total thicknesses of the ligamenta flava in group II was thicker than in group I. There was no spinal stenosis in either group and no significance difference between the groups. Statistically significant differences were found for both ipsilateral and contralateral thickness of the ligament flava in both groups. We also compared thickness of the ligamenta flava for each level of disc herniation in group I; ligamenta flava hypertrophy was more common at L3-L4 and L4-L5 levels of vertebrae in females. Conclusions Aetiology of contralateral sciatica among disc herniated patients may be related to hypertrophy of the ligamenta flava, especially on the opposite side. Surgical approaches of the disc herniated side alone may be sufficient for a good outcome. PMID:22371809

  14. Prognostic factors for return to work after low-back disc herniation surgery.

    PubMed

    Seyedmehdi, Mohammad; Attarchi, Mirsaeed; Ghaffari, Mostafa; Mohammadi, Saber; Darnahal, Maryam; Sadeghi, Zargham

    2015-03-01

    Return to work (RTW) is an important outcome following disc herniation surgery. The present study aimed at determining factors that may affect early RTW after disc herniation surgery. Data were collected from 603 patients who underwent disc herniation surgery in an educational hospital via phone interviews during a 4-year period (2005-2009). Delayed RTW and failed RTW were associated with female gender, lower educational levels, longer hospitalization periods, greater BMI, biological age exceeding 40 years, employment in manual labor, lack of encouragement by the physician to RTW, being in pain at the time of the phone interview, having negative expectations about the outcome of surgery preoperatively, and low job satisfaction (P < .05). Psychological and occupational factors have direct effects on RTW. Important factors include positive expectations about the outcome of surgery, encouragement by the physician to RTW, job characteristics, and job satisfaction. RTW can be accelerated by appropriate strategies and team work. PMID:23293315

  15. Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly.

    PubMed

    Y?lmaz, Tevfik; Turan, Yahya; Gül?en, Ismail; Dalbayrak, Sedat

    2014-04-01

    Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury. PMID:25210343

  16. Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly

    PubMed Central

    Y?lmaz, Tevfik; Turan, Yahya; Gül?en, ?smail; Dalbayrak, Sedat

    2014-01-01

    Lumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury. PMID:25210343

  17. Percutaneous cervical nucleoplasty and percutaneous cervical discectomy treatments of the contained cervical disc herniation

    Microsoft Academic Search

    Denglu YanJian; Jian Li; Haodong Zhu; Zhi Zhang; Lijun Duan

    2010-01-01

    Background  There were no studies in literature to compare the clinical outcomes of percutaneous nucleoplasty (PCN) and percutaneous cervical\\u000a discectomy (PCD) in contained cervical disc herniation.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  A retrospective of patients with symptomatic contained cervical disc herniated were operated on with PCN and PCD from June\\u000a 2003 to July 2005. Two-hundred and four patients initially fulfilled the study criteria, and 28 patients

  18. Is there any relationship between proinflammatory mediator levels in disc material and myelopathy with cervical disc herniation and spondylosis? A non-randomized, prospective clinical study

    Microsoft Academic Search

    Mehmet Nusret Demircan; Alparslan Asir; Ahmet Cetinkal; Nursal Gedik; Ahmet Murat Kutlay; Ahmet Çolak; Sedat Kurtar; Hakan Simsek

    2007-01-01

    The proinflammatory mediator (PIM) levels were assessed in surgically removed samples of herniated cervical intervertebral\\u000a discs. The objective of this study was to investigate if there is a correlation between the levels of PIMs in disc material\\u000a and myelopathy associated with cervical intervertebral disc herniation and spondylosis. The role of proinflammatory mediators\\u000a in the degeneration of intervertebral disc and the

  19. Lumbar Disc Herniation in a Patient With Congenital Vertebral Body Anomaly: A Case Report

    PubMed Central

    Atabey, Cem; Topuz, Ali Kivanc; Velio?lu, Murat; Demircan, Mehmet Nusret

    2014-01-01

    Lumbar disc herniation is characterized with low back and leg pain resulting from the degenerated lumbar disc compressing the spinal nerve root. The etiology of degenerative spine is related to age, smoking, microtrauma, obesity, disorders of familial collagen structure, occupational and sports-related physical activity. However, disc herniations induced by congenital lumbar vertebral anomalies are rarely seen. Vertebral fusion defect is one of the causes of congenital anomalies. The pathogenesis of embryological corpus vertebral fusion anomaly is not fully known. In this paper, a 30-year-old patient who had the complaints of low back and right leg pain after falling from a height is presented. She had right L5-S1 disc herniation that had developed on the basis of S1 vertebra corpus fusion anomaly in Lumbar computed tomography. This case has been discussed in the light of literature based on evaluations of Lumbar Computed Tomography (CT) and Magnetic Resonance Imaging (MRI). This case is unique in that it is the first case with development of lumbar disc herniation associated with S1 vertebral corpus fusion anomaly. Congenital malformations with unusual clinical presentation after trauma should be evaluated through advanced radiological imaging techniques. PMID:25620987

  20. Endoscopic transforaminal thoracic foraminotomy and discectomy for the treatment of thoracic disc herniation.

    PubMed

    Nie, Hong-Fei; Liu, Kai-Xuan

    2013-01-01

    Thoracic disc herniation is a relatively rare yet challenging-to-diagnose condition. Currently there is no universally accepted optimal surgical treatment for symptomatic thoracic disc herniation. Previously reported surgical approaches are often associated with high complication rates. Here we describe our minimally invasive technique of removing thoracic disc herniation, and report the primary results of a series of cases. Between January 2009 and March 2012, 13 patients with symptomatic thoracic disc herniation were treated with endoscopic thoracic foraminotomy and discectomy under local anesthesia. A bone shaver was used to undercut the facet and rib head for foraminotomy. Discectomy was achieved by using grasper, radiofrequency, and the Holmium-YAG laser. We analyzed the clinical outcomes of the patients using the visual analogue scale (VAS), MacNab classification, and Oswestry disability index (ODI). At the final follow up (mean: 17 months; range: 6-41 months), patient self-reported satisfactory rate was 76.9%. The mean VAS for mid back pain was improved from 9.1 to 4.2, and the mean ODI was improved from 61.0 to 43.8. One complication of postoperative spinal headache occurred during the surgery and the patient was successfully treated with epidural blood patch. No other complications were observed or reported during and after the surgery. PMID:24455232

  1. Automatic Diagnosis of Lumbar Disc Herniation with Shape and Appearance Features from MRI

    E-print Network

    Corso, Jason J.

    ) CAD using MRI for detection of breast9 and prostate10 cancer. More recently, major attention has beenAutomatic Diagnosis of Lumbar Disc Herniation with Shape and Appearance Features from MRI Raja' S diagnosis reduces the large burden on radiologists who have to diagnose hundreds of cases each day using

  2. Massive epidural varix mimicking lumbar disc herniation: case report and literature review.

    PubMed

    Kramer, Kenneth M

    2014-10-01

    Sciatica is generally caused by such well-recognized entities as lumbar disc herniation and degenerative stenosis. A rarely reported alternative cause of lumbar nerve root compression is by distended epidural veins. A case is presented of sciatica produced by such a mechanism, successfully treated by decompressive laminotomy. PMID:25675591

  3. [Acupuncture combined with traction therapy for lumbar disc herniation: a systematic review].

    PubMed

    Li, Xiu-zhen; Chen, Hai-yong; Zheng, Xiao; Liu, Nong-yu

    2014-09-01

    To evaluate the efficacy and safety of acupuncture combined with traction therapy for lumbar disc herniation, providing the basis for future research strategies. Randomized control trials. (RCT) of acupuncture combined with traction therapy for lumber disc herniation at home and abroad from 2000 to 2013 were searched, analysis and evaluation of literature and strength of evidence were based on the principles and methods of Evidence-based Medicine. The total effective rate and curative rate were considered as primary outcome measures; pain improvement, quality of life, relapse rate and adverse effects were considered as secondary outcome measures. Seventeen RCTs were identified, Meta-analysis showed that (1) total effective rate and curative rate: acupuncture combined with traction therapy was better than single therapy (acupuncture or traction); (2) pain improvement: acupuncture combined with traction therapy was better than traction therapy; (3) relapse rate: current evidence could not support the conclusion that acupuncture combined with traction therapy was better than traction therapy. Acupuncture combined with traction therapy for lumbar disc herniation was effective. However, the included studies were with high risk of bias, important outcome measures such as quality of life, relapse rate and adverse effects were not found in most of the studies. Current evidence has not yet been able to fully reflect acupuncture combined with traction therapy for lumbar disc herniation is better than single therapy, so more RCTs of higher quality are needed to further confirm its efficacy and safety. PMID:25509761

  4. Genotypic and antimicrobial characterisation of Propionibacterium acnes isolates from surgically excised lumbar disc herniations.

    PubMed

    Rollason, Jess; McDowell, Andrew; Albert, Hanne B; Barnard, Emma; Worthington, Tony; Hilton, Anthony C; Vernallis, Ann; Patrick, Sheila; Elliott, Tom; Lambert, Peter

    2013-01-01

    The anaerobic skin commensal Propionibacterium acnes is an underestimated cause of human infections and clinical conditions. Previous studies have suggested a role for the bacterium in lumbar disc herniation and infection. To further investigate this, five biopsy samples were surgically excised from each of 64 patients with lumbar disc herniation. P. acnes and other bacteria were detected by anaerobic culture, followed by biochemical and PCR-based identification. In total, 24/64 (38%) patients had evidence of P. acnes in their excised herniated disc tissue. Using recA and mAb typing methods, 52% of the isolates were type II (50% of culture-positive patients), while type IA strains accounted for 28% of isolates (42% patients). Type III (11% isolates; 21% patients) and type IB strains (9% isolates; 17% patients) were detected less frequently. The MIC values for all isolates were lowest for amoxicillin, ciprofloxacin, erythromycin, rifampicin, tetracycline, and vancomycin (?1 mg/L). The MIC for fusidic acid was 1-2 mg/L. The MIC for trimethoprim and gentamicin was 2 to ?4 ?mg/L. The demonstration that type II and III strains, which are not frequently recovered from skin, predominated within our isolate collection (63%) suggests that the role of P. acnes in lumbar disc herniation should not be readily dismissed. PMID:24066290

  5. Genotypic and Antimicrobial Characterisation of Propionibacterium acnes Isolates from Surgically Excised Lumbar Disc Herniations

    PubMed Central

    Rollason, Jess; Albert, Hanne B.; Barnard, Emma; Worthington, Tony; Hilton, Anthony C.; Vernallis, Ann; Patrick, Sheila; Elliott, Tom

    2013-01-01

    The anaerobic skin commensal Propionibacterium acnes is an underestimated cause of human infections and clinical conditions. Previous studies have suggested a role for the bacterium in lumbar disc herniation and infection. To further investigate this, five biopsy samples were surgically excised from each of 64 patients with lumbar disc herniation. P. acnes and other bacteria were detected by anaerobic culture, followed by biochemical and PCR-based identification. In total, 24/64 (38%) patients had evidence of P. acnes in their excised herniated disc tissue. Using recA and mAb typing methods, 52% of the isolates were type II (50% of culture-positive patients), while type IA strains accounted for 28% of isolates (42% patients). Type III (11% isolates; 21% patients) and type IB strains (9% isolates; 17% patients) were detected less frequently. The MIC values for all isolates were lowest for amoxicillin, ciprofloxacin, erythromycin, rifampicin, tetracycline, and vancomycin (?1mg/L). The MIC for fusidic acid was 1-2 mg/L. The MIC for trimethoprim and gentamicin was 2 to ?4?mg/L. The demonstration that type II and III strains, which are not frequently recovered from skin, predominated within our isolate collection (63%) suggests that the role of P. acnes in lumbar disc herniation should not be readily dismissed. PMID:24066290

  6. Posterior approach for cervical fracture–dislocations with traumatic disc herniation

    Microsoft Academic Search

    Hiroaki Nakashima; Yasutsugu Yukawa; Keigo Ito; Masaaki Machino; Hany El Zahlawy; Fumihiko Kato

    2011-01-01

    In the treatment algorithm for cervical spine fracture–dislocations, the recommended approach for treatment if there is a\\u000a disc fragment in the canal is the anterior approach. The posterior approach is not common because of the disadvantage of potential\\u000a neurological deterioration during reduction in traumatic cervical herniation patients. However, reports about the frequency\\u000a of this deterioration and the behavior of disc

  7. Lumbar disc herniation in a child with cystic fibrosis: case report.

    PubMed

    Alexiou, George A; Stefanaki, Kalliopi; Sfakianos, George; Prodromou, Neofytos

    2014-04-01

    We report a case of child with cystic fibrosis and lumbar disc herniation. An 8-year-old boy presented with low back pain that exacerbated on coughing, sitting, walking, or bending and diminished when lying down. The straight leg raising test was positive when the right leg was lifted at 60 degrees. Crossed leg raising test was negative. Lumbar MRI revealed a L5-S1central disc protrusion. Conservative treatment was not effective and the patient underwent surgery. Postoperatively the patient experienced regression of the pain. To the best of our knowledge this is the first reported case of lumbar disc herniation in a child with cystic fibrosis. Although this case might be coincidental, thorough investigation of back pain, which is frequent in patients with cystic fibrosis, should be performed. PMID:24584798

  8. Revisional Percutaneous Full Endoscopic Disc Surgery for Recurrent Herniation of Previous Open Lumbar Discectomy

    PubMed Central

    Chang, Ho-Guen; Rhee, Nam Kyou; Lim, Kwahn Sue

    2011-01-01

    Study Design A retrospective study. Purpose To determine the feasibility and effectiveness of revisional percutaneous full endoscopic discectomy for recurrent herniation after conventional open disc surgery. Overview of the Literature Repeated open discectomy with or without fusion has been the most common procedure for recurrent lumbar disc herniation. Percutaneous endoscopic lumbar discectomy for recurrent herniation has been thought of as an impossible procedure. Despite good results with open revisional surgery, major problems may be caused by injuries to the posterior stabilized structures. Our team did revisional full endoscopic lumbar disc surgery on the basis of our experience doing primary full endoscopic disc surgery. Methods Between February 2004 and August 2009 a total of 41 patients in our hospital underwent revisional percutaneous endoscopic lumbar discectomy using a YESS endoscopic system and a micro-osteotome (designed by the authors). Indications for surgery were recurrent disc herniation following conventional open discectomy; with compression of the nerve root revealed by Gadolinium-enhanced magnetic resonance imaging; corresponding radiating pain which was not alleviated after conservative management over 6 weeks. Patients with severe neurologic deficits and isolated back pain were excluded. Results The mean follow-up period was 16 months (range, 13 to 42 months). The visual analog scale for pain in the leg and back showed significant post-treatment improvement (p < 0.001). Based on a modified version of MacNab's criteria, 90.2% showed excellent or good outcomes. There was no measurable blood loss. There were two cases of recurrence of and four cases with complications. Conclusions Percutaneous full-endoscopic revisional disc surgery without additional structural damage is feasible and effective in terms of there being less chance of fusion and bleeding. This technique can be an alternative to conventional repeated discectomy. PMID:21386940

  9. Comparison of Discectomy versus Sequestrectomy in Lumbar Disc Herniation: A Meta-Analysis of Comparative Studies

    PubMed Central

    Ran, Jisheng; Hu, Yejun; Zheng, Zefeng; Zhu, Ting; Zheng, Huawei; Jing, Yibiao; Xu, Kan

    2015-01-01

    Background Lumbar disc removal is currently the standard treatment for lumbar disc herniation. No consensus has been achieved whether aggressive disc resection with curettage (discectomy) versus conservative removal of the offending disc fragment alone (sequestrectomy) provides better outcomes. This study aims to compare the reherniation rate and clinical outcomes between discectomy and sequestrectomy by literature review and a meta-analysis. Methods A systematic search of PubMed, Medline, Embase and the Cochrane Library was performed up to June 1, 2014. Outcomes of interest assessing the two techniques included demographic and clinical baseline characteristics, perioperative variables, complications, recurrent herniation rate and post-operative functional outcomes. Results Twelve eligible trials evaluating discectomy vs sequestrectomy were identified including one randomized controlled study, five prospective and six retrospective comparative studies. By contrast to discectomy, sequestrectomy was associated with significantly less operative time (p<0.001), lower visual analogue scale (VAS) for low back pain (p<0.05), less post-operative analgesic usage (p<0.05) and better patients’ satisfaction (p<0.05). Recurrent herniation rate, reoperation rate, intraoperative blood loss, hospitalization duration and VAS for sciatica were without significant difference. Conclusions According to our pooled data, sequestrectomy entails equivalent reherniation rate and complications compared with discectomy but maintains a lower incidence of recurrent low back pain and higher satisfactory rate. High-quality prospective randomized controlled trials are needed to firmly assess these two procedures. PMID:25815514

  10. [Far lateral lumbar disc herniation: clinical and radiographical features of three cases].

    PubMed

    Fujisawa, H; Igarashi, S; Koyama, T

    1996-04-01

    The authors report three operated cases of far lateral lumbar disc herniation (FLLDH) during the past two years and discuss their diagnostic pitfalls. Until recently FLLDH was hardly ever diagnosed because the myelography was negative in almost all cases. Since the advent of CT and/or MRI, FLLDH has been found to be not such a rare entity. FLLDH has also been found to reveal characteristic clinical features and radiographical findings. Usual lumbar disc herniations occur at L4/5 or L5/S1 levels, producing low back pain with the pain or sensory disturbance from the posterolateral thigh down to the foot. In contrast, FLLDH affects upper lumbar levels and produces severe anterolateral thigh pain, dysesthesia resulting from nerve root or dorsal root ganglion (DRG) compression in the foraminal or extraforaminal region. The level predilection of these two groups can be attributed to the difference of the facet joint planes between the upper and lower lumbar levels. The facets with a coronal plane are resistant to lateral bending and rotational forces, but those with a sagittal plane are unstable resulting in more shearing stress to the intervertebral discs. A patient with definite neurological signs but a negative myelography should be examined for FLLDH by using a high-resolution CT or MRI. MRI clearly shows the detailed anatomical relationships between herniated disc and nerve root or DRG in the foraminal and extraforaminal regions. As well as thin-sliced axial images, sagittal MR images that include the foraminal zone are useful for detecting a direct nerve root compression from FLLDH. The authors conclude that gait disturbance due to severe leg pain, antero-lateral thigh pain or dysesthesia are characteristic of FLLDH, and that either a foraminal or extraforaminal herniated disc or both on a CT and/or MRI are diagnostic radiographical findings of FLLDH. PMID:8934890

  11. Extreme lateral lumbar disc herniation in a 12-year child: case report and review of the literature

    Microsoft Academic Search

    Sheng-Dan Jiang; Lei-Sheng Jiang; Li-Yang Dai

    2010-01-01

    Extreme lateral lumbar disc herniations (ELLDHs) occur more frequently among elderly patients, with a peak incidence in the\\u000a sixth decade, and are rarely found in children. The patient presented is a 12-year-old boy with a 3-month history of right-sided\\u000a leg pain. Computerized tomography and magnetic resonance imaging demonstrated an extreme lateral disc herniation on the right\\u000a at L4–L5 with compression

  12. Peridural scar and its relation to clinical outcome: a randomised study on surgically treated lumbar disc herniation patients

    Microsoft Academic Search

    Katarina Rönnberg; B. Lind; B. Zoega; G. Gadeholt-Göthlin; K. Halldin; M. Gellerstedt; H. Brisby

    2008-01-01

    A prospective randomised 2-year follow-up study on patients undergoing lumbar disc herniation surgery. The objective was to\\u000a investigate the relationship between peridural scarring and clinical outcome, the scar development 6 and 24 months postoperatively\\u000a by using MRI, and if ADCON-L (a bioresorbable carbohydrate polymer gel) has an effect on scar size and\\/or improve patients’\\u000a outcome after lumbar disc herniation surgery. The

  13. Herniated intervertebral disc associated with a lumbar spine dislocation as a cause of Cauda Equina syndrome: a case report

    Microsoft Academic Search

    Gaby E. Kreichati; Farid N. Kassab; Khalil E. Kharrat

    2006-01-01

    To report a case of Cauda Equina syndrome with the completion of the paralysis after the reduction of a L4L5 dislocation due to a herniated disc. Although several articles have described a post-traumatic disc herniation in the cervical spinal canal, this is not well known in the lumbar region. A 30-year-old man was admitted to the emergency room with blunt

  14. Comparison of Percutaneous Endoscopic Lumbar Discectomy and Open Lumbar Microdiscectomy for Recurrent Disc Herniation

    PubMed Central

    Lee, Dong Yeob; Shim, Chan Shik; Ahn, Yong; Choi, Young-Geun; Kim, Ho Jin

    2009-01-01

    Objective The purpose of this study was to compare clinical and radiological outcomes of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar microdiscectomy (OLM) for recurrent disc herniation. Methods Fifty-four patients, who underwent surgery, either PELD (25 patients) or repeated OLM (29 patients), due to recurrent disc herniation at L4-5 level, were divided into two groups according to the surgical methods. Excluded were patients with sequestrated disc, calcified disc, severe neurological deficit, or instability. Clinical outcomes were assessed using Visual Analogue Scale (VAS) score and Oswestry Disability Index (ODI). Radiological variables were assessed using plain radiography and/or magnetic resonance imaging. Results Mean operating time and hospital stay were significantly shorter in PELD group (45.8 minutes and 0.9 day, respectively) than OLM group (73.8 minutes and 3.8 days, respectively) (p < 0.001). Complications occurred in 4% in PELD group and 10.3% in OLM group in the perioperative period. At a mean follow-up duration of 34.2 months, the mean improvements of back pain, leg pain, and functional improvement were 4.0, 5.5, and 40.9% for PELD group and 2.3, 5.1, and 45.0% for OLM group, respectively. Second recurrence occurred in 4% after PELD and 10.3% after OLM. Disc height did not change after PELD, but significantly decreased after OLM (p = 0.0001). Neither sagittal rotation angle nor volume of multifidus muscle changed significantly in both groups. Conclusion Both PELD and repeated OLM showed favorable outcomes for recurrent disc herniation, but PELD had advantages in terms of shorter operating time, hospital stay, and disc height preservation. PMID:20062565

  15. A history of lumbar disc herniation from hippocrates to the 1990s.

    PubMed

    Truumees, Eeric

    2015-06-01

    In ancient times, a supernatural understanding of the syndrome of lumbar radiculopathy often involved demonic forces vexing the individual with often crippling pain. The ancient Greeks and Egyptians began to take a more naturalistic view and, critically, suspected a relationship between lumbar spinal pathology and leg symptoms. Relatively little then changed for those with sciatica until the classic works by Cotugno and Kocher arrived in the late 18th century. Early lumbar canal explorations were performed in the late 1800s and early 1900s by MacEwen, Horsley, Krause, Taylor, Dandy, and Cushing, among others. In these cases, when compressive pathologies were found and removed, the lesions typically were (mis-)identified as enchondromas or osteochondritis dissecans. To better understand the history, learn more about the first treatments of lumbar disc herniation, and evaluate the impact of the early influences on modern spine practice, searches of PubMed and Embase were performed using the search terms discectomy, medical history, lumbar spine surgery, herniated disc, herniated nucleus pulposus, sciatica, and lumbar radiculopathy. Additional sources were identified from the reference lists of the reviewed papers. Many older and ancient sources including De Ischiade Nervosa are available in English translations and were used. When full texts were not available, English abstracts were used. The first true, intentional discectomy surgery was performed by Mixter and Barr in 1932. Early on, a transdural approach was favored. In 1938, Love described the intralaminar, extradural approach. His technique, although modified with improved lighting, magnification, and retractors, remains a staple approach to disc herniations today. Other modalities such as chymopapain have been investigated. Some remain a part of the therapeutic armamentarium, whereas others have disappeared. By the 1970s, CT scanning after myelography markedly improved the clinical evaluation of patients with lumbar disc herniation. In this era, use of discectomy surgery increased rapidly. Even patients with very early symptoms were offered surgery. Later work, especially by Weber and Hakelius, showed that many patients with lumbar disc herniation would improve without surgical intervention. In the ensuing decades, the debate over operative indications and timing continued, reaching another pivotal moment with the 2006 publication of the initial results of Spine Patient Outcomes Research Trial. PMID:24752913

  16. The Impact of Epidural Steroid Injections on the Outcomes of Patients Treated for Lumbar Disc Herniation

    PubMed Central

    Radcliff, Kristen; Hilibrand, Alan; Lurie, Jon D.; Tosteson, Tor D.; Delasotta, Lawrence; Rihn, Jeffrey; Zhao, Wenyan; Vaccaro, Alexander; Albert, Todd J.; Weinstein, James N.

    2012-01-01

    Background: The Spine Patient Outcomes Research Trial (SPORT) is a prospective, multicenter study of operative versus nonoperative treatment of lumbar intervertebral disc herniation. It has been suggested that epidural steroid injections may help improve patient outcomes and lower the rate of crossover to surgical treatment. Methods: One hundred and fifty-four patients included in the intervertebral disc herniation arm of the SPORT who had received an epidural steroid injection during the first three months of the study and no injection prior to the study (the ESI group) were compared with 453 patients who had not received an injection during the first three months of the study or prior to the study (the No-ESI group). Results: There was a significant difference in the preference for surgery between groups (19% in the ESI group compared with 56% in the No-ESI group, p < 0.001). There was no difference in primary or secondary outcome measures at four years between the groups. A higher percentage of patients changed from surgical to nonsurgical treatment in the ESI group (41% versus 12% in the No-ESI, p < 0.001). Conclusions: Patients with lumbar disc herniation treated with epidural steroid injection had no improvement in short or long-term outcomes compared with patients who were not treated with epidural steroid injection. There was a higher prevalence of crossover to nonsurgical treatment among surgically assigned ESI-group patients, although this was confounded by the increased baseline desire to avoid surgery among patients in the ESI group. Given these data, we concluded that more studies are necessary to establish the value of epidural steroid injection for symptomatic lumbar intervertebral disc herniation. Level of Evidence: Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:22739998

  17. The clinical significance of gadolinium enhancement of lumbar disc herniations and nerve roots on preoperative MRI

    Microsoft Academic Search

    P. C. A. J. Vroomen; S. J. M. Van Hapert; R. E. H. Van Acker; E. A. M. Beuls; A. G. H. Kessels; J. T. Wilmink

    1998-01-01

    The clinical significance of preoperative gadolinium DPTA enhancement around disc herniations and in the epidural space on\\u000a MRI is not clear. The relation of nerve root enhancement to dysfunction also remains controversial. To investigate the clinical\\u000a significance of contrast enhancement we looked at the symptoms and signs and gadolinium DPTA-enhanced images of 71 consecutive\\u000a surgical candidates in a standardised fashion.

  18. Sacroiliac joint dysfunction in patients with imaging-proven lumbar disc herniation

    Microsoft Academic Search

    R. Galm; M. Fröhling; M. Rittmeister; E. Schmitt

    1998-01-01

    A dysfunction of a joint is defined as a reversible functional restriction of motion presenting with hypomobility according\\u000a to manual medicine terminology. The aim of our study was to evaluate the frequency and significance of sacroiliac joint (SIJ)\\u000a dysfunction in patients with low back pain and sciatica and imaging-proven disc herniation. We examined the SIJs of 150 patients\\u000a with low

  19. Microsurgical cordotomy in 20 patients with epi-\\/intradural fibrosis following operation for lumbar disc herniation

    Microsoft Academic Search

    Ch. Probst

    1990-01-01

    Summary Using an improved microsurgical technique, cordotomy was carried out by the cervicothoracic route in 20 patients with persistent radicular pain due to epi-\\/intradural fibrosis following operation for lumbar disc herniation. 65% of them had good long-term results with respect to radicular pain (follow-up period 6–132 months; mean 66 months). Permanent severe motor impairment was not observed. In patients with

  20. Estimates of success in patients with sciatica due to lumbar disc herniation depend upon outcome measure

    Microsoft Academic Search

    Anne Julsrud Haugen; Lars Grøvle; Jens Ivar Brox; Bård Natvig; Anne Keller; Dag Soldal; Margreth Grotle

    The objectives were to estimate the cut-off points for success on different sciatica outcome measures and to determine the\\u000a success rate after an episode of sciatica by using these cut-offs. A 12-month multicenter observational study was conducted\\u000a on 466 patients with sciatica and lumbar disc herniation. The cut-off values were estimated by ROC curve analyses using Completely recovered or Much

  1. When should conservative treatment for lumbar disc herniation be ceased and surgery considered?

    Microsoft Academic Search

    Ralf D. Rothoerl; Chris Woertgen; Alexander Brawanski

    2002-01-01

    .   Different authors recommend different time spans for conservative treatment before considering surgery in patients suffering\\u000a from lumbar disc herniation. We analyzed the time of onset of symptoms such as pain, sensory deficit, and motor deficit in\\u000a a surgically treated group in comparison to outcome after surgery in order to define a time threshold when surgical results\\u000a deteriorate and operation

  2. A systematic review of randomised clinical trials using posterior discectomy to treat lumbar disc herniations

    Microsoft Academic Search

    Alberto Gotfryd; Osmar Avanzi

    2009-01-01

    The focus of this study was to examine the safety and effectiveness of three different discectomy techniques using a posterior\\u000a approach for the treatment of herniated lumbar discs. There are only a small number of prospective randomised studies comparing\\u000a posterior lumbar discectomy techniques, and no recent systematic review has been published on this matter. Using the Cochrane\\u000a Collaboration guidelines, all

  3. Ten to 15-year outcome of surgery for lumbar disc herniation: radiographic instability and clinical findings

    Microsoft Academic Search

    R. Padua; S. Padua; E. Romanini; L. Padua; E. De Santis

    1999-01-01

    The most appropriate treatment for radiculopathy associated with disc pathology is still controversial. Since 1934, surgical\\u000a treatment has consisted of hemilaminectomy and removal of the herniated material. Many authors believe that these procedures\\u000a may cause degenerative spondylosis and vertebral instability. Several surgical methods have been proposed, but the long-term\\u000a effects are still being debated. In addition there appear to be

  4. Matrix metalloproteinase expression levels suggest distinct enzyme roles during lumbar disc herniation and degeneration

    PubMed Central

    Bachmeier, Beatrice E.; Nerlich, Andreas; Mittermaier, Norbert; Weiler, Christoph; Lumenta, Christianto; Wuertz, Karin

    2009-01-01

    The disruption of the extracellular disc matrix is a major hallmark of disc degeneration. This has previously been shown to be associated with an up-regulation of major matrix metalloproteinase (MMP) expression and activity. However, until now hardly any data are available for MMP/TIMP regulation and thereby no concept exists as to which MMP/TIMP plays a major role in disc degeneration. The objective of this study was, therefore, to identify and quantify the putative up-regulation of MMPs/TIMPs on the mRNA and protein level and their activity in disc material in relation to clinical data and histological evidence for disc degeneration. A quantitative molecular analysis of the mRNA expression levels for the MMPs (MMPs-1, -2, -3, -7, -8, -9, -13) and the MMP inhibitors (TIMPs-1 and -2) was performed on 37 disc specimens obtained from symptomatic disc herniation or degeneration. In addition, disc specimens from patients without disc degeneration/herniation (=controls) were analyzed. Expression of MMPs-1, -2, -3, -7, -8, -9, -13 and TIMPs-1, -2 was analyzed using quantitative RT-PCR, normalized to the expression level of a house keeping gene (GAPDH). Gene expression patterns were correlated with MMP activity (in situ zymography), protein expression patterns (immunohistochemistry), degeneration score (routine histology) and clinical data. MMP-3 mRNA levels were consistently and substantially up-regulated in samples with histological evidence for disc degeneration. A similar but less pronounced up-regulation was observed for MMP-8. This up-regulation was paralleled by the expression of TIMP-1 and to a lesser extent TIMP-2. In general, these findings could be confirmed with regard to protein expression and enzyme activity. This study provides data on the gene and protein level, which highlights the key role of MMP-3 in the degenerative cascade leading to symptomatic disc degeneration and herniation. Control of the proteolytic activity of MMP-3 may, therefore, come into the focus when aiming to develop new treatment options for early disc degeneration. PMID:19466462

  5. Lumbar Spine Disc Herniation Diagnosis with a Joint Shape Model

    E-print Network

    Corso, Jason J.

    an active shape model (ASM) and a gradient vector flow snake model (GVF-snake). The ASM roughly segments distribution to initial- ize a GVF-snake model to delineate the posterior disc segment. We then extract the set

  6. Comparison of Two Methods of Epidural Steroid Injection in the Treatment of Recurrent Lumbar Disc Herniation

    PubMed Central

    Ebrahimi-Nejad, Ali; Shahsavarani, Shahram; Keikhosravi, Ehsan; Shahba, Mohsen; Ebrahimi, Farzaneh

    2014-01-01

    Study Design Prospective study. Purpose We compared the effects of two methods of epidural steroid injection in patients with recurrent disc herniation. Overview of Literature To our knowledge, there is no previous report of such a comparison in these patients. Methods The study was performed with 30 patients with relapsed lumbar disc herniation whose pain was not relieved by conservative remedies. The patients were divided into two groups, each of 15 patients, and entered the study for caudal or transforaminal injections. The degree of pain, ability to stand and walk, and the Prolo function score were evaluated in both groups before the injection and 2 months and 6 months after the injection. Results The degrees of pain reduction in the caudal injection group in the second and sixth months were 0.6 and 1.63, respectively, and in the transforaminal injection group were 1.33 and 1.56, respectively. The difference between the two methods was not statistically significant. Similarly, no other evaluated criterion showed a significant difference between the methods. Conclusions In the current study, the caudal and transforaminal steroid injection methods showed similar outcomes in the treatment of relapsed lumbar disc herniation. However, more detailed patient categorizing may help in finding possible subgroups with differences. PMID:25346818

  7. A systematic review of randomised clinical trials using posterior discectomy to treat lumbar disc herniations

    PubMed Central

    Avanzi, Osmar

    2008-01-01

    The focus of this study was to examine the safety and effectiveness of three different discectomy techniques using a posterior approach for the treatment of herniated lumbar discs. There are only a small number of prospective randomised studies comparing posterior lumbar discectomy techniques, and no recent systematic review has been published on this matter. Using the Cochrane Collaboration guidelines, all randomised or “quasi-randomised” clinical trials, comparing classic, microsurgical, and endoscopic lumbar discectomies using a posterior approach were systematically reviewed. No statistically significant differences were found between these techniques regarding improvement in pain, sensory deficits, motor strength, reflexes, and patient satisfaction. Current data suggest that the microsurgical and endoscopic techniques are superior to the classic technique for the treatment of single level lumbar disc herniations with respect to volume of blood loss, systemic repercussions, and duration of hospital stay. All three surgical techniques were found to be effective for the treatment of single level lumbar disc herniations in patients without degenerative vertebral deformities. No conclusions could be drawn from the clinical randomised studies reviewed regarding the safety of the three techniques studied due to insufficient data on postoperative complications. PMID:18500517

  8. Calcified thoracic disc with herniation of the nucleus pulposus in a child.

    PubMed Central

    Schapira, D.; Goldsher, D.; Nahir, M.; Scharf, Y.

    1988-01-01

    A twelve year old boy presented with acute cervical and interscapular pain, torticollis and low grade fever. The neurological examination was normal. Roentgenograms showed calcification of the T3-T4 disc and posterior herniation of the nucleus pulposus was demonstrated by computed tomography. A rapid and dramatic amelioration of the symptoms was produced by treatment with a non-steroidal anti-inflammatory drug. Intervertebral disc calcification in childhood is an uncommon and usually benign condition. Its clinical and radiological features are discussed in the light of the relevant literature. Images Figure 1 Figure 2 Figure 3 PMID:3174531

  9. Migration of lumbar disc herniation: An unusual case

    Microsoft Academic Search

    Ralph J. Mobbs; T. R. Steel

    2007-01-01

    We illustrate a patient with a migrating lumbar disc fragment that caused a change in radicular symptoms from the L3 nerve root on one side to the L5 nerve root on the contralateral side, documented by magnetic resonance imaging (MRI). Our patient presented with 3 months of L3 pain on the right side with sensory and motor changes. Over a

  10. Endoscopic Transforaminal Suprapedicular Approach in High Grade Inferior Migrated Lumbar Disc Herniation

    PubMed Central

    Kim, Hyeun Sung; Kim, Seok Won; Kim, Jong Gue

    2009-01-01

    Objective Although endoscopic procedures for lumbar disc diseases have improved greatly, the postoperative outcomes for high grade inferior migrated discs are not satisfactory. Because of anatomic limitations, a rigid endoscope cannot reach all lesions effectively. The purpose of this study was to determine the feasibility of endoscopic transforaminal suprapedicular approach to high grade inferior-migrated lumbar disc herniations. Methods Between May 2006 and March 2008, a suprapedicular approach was performed in 53 patients with high grade inferior-migrated lumbar disc herniations using a rigid endoscope and a semi-rigid flexible curved probe. One-to-four hours after surgery, the presence of remnant discs was checked with MRI. The outcomes were evaluated with the visual analogue scale (VAS) score and the Oswestry Disability Index (ODI) one week after surgery. Results The L2-3 level was involved in 2 patients and the L3-4 level was involved in 14 patients, while the L4-5 level was involved in 39 patients. There were single piece-type in 34 cases and a multiple piece-type in 19 cases. Satisfactory results were obtained in all cases. The mean preoperative VAS for leg pain was 9.32±0.43 points (range, 7-10 points), whereas the mean ODI was 79.82±4.53 points (range, 68-92 points). At the last follow-up examination, the mean postoperative VAS for leg pain was 1.78±0.71 points and the mean postoperative ODI improved to 15.27±3.82 points. Conclusion A high grade inferior migrated lumbar disc is difficult to remove sufficiently by posterolateral endoscopic lumbar dscectomy using a rigid endoscope. However, a satisfactory result can be obtained by applying a transforaminal suprapedicular approach with a flexible semi-rigid curved probe. PMID:19274114

  11. Surgery for Recurrent Lumbar Disc Herniation During Pregnancy: A Case Report

    PubMed Central

    Lee, Jae Meen; Moon, Soo Hyeon; Choi, Byung Kwan

    2011-01-01

    A few cases of lumbar disc herniation (LDH) that have been treated by surgery during pregnancy have been reported in the literature. However, symptomatic recurrent LDH during pregnancy has been rarely reported. A 32-year-old parous woman presented with lumbago and severe right leg pain at 20 weeks' gestation. Eleven years prior to admission, she had undergone an open discectomy for right-sided LDH at the L4-5 level. Magnetic resonance imaging (MRI) showed a recurrent disc herniation that affected the nerve root at the right L4-5 level. The radiating pain did not respond to conservative treat-ment. Revision surgery was performed under general anesthesia and in the left lateral position to avoid fetal stress and aortocaval compression, and the ruptured disc particle was completely removed. Postoperatively, the radiating pain was completely relieved. She delivered a full-term healthy girl (birth weight, 3.39 kg) at 40 weeks' gestation by normal vaginal delivery. We report the rare case of a 32-year-old parous woman with recurrent LDH that was successfully treated by revision surgery. In recurrent LDH patients with incapacitating pain who do not respond to opioid injections, surgical treat-ment could lead to a satisfactory outcome maintaining pregnancy.

  12. Transforaminal endoscopic surgery for symptomatic lumbar disc herniations: a systematic review of the literature

    PubMed Central

    Nellensteijn, Jorm; Bartels, Ronald; Peul, Wilco; van Royen, Barend; van Tulder, Maurits

    2009-01-01

    The study design includes a systematic literature review. The objective of the study was to evaluate the effectiveness of transforaminal endoscopic surgery and to compare this with open microdiscectomy in patients with symptomatic lumbar disc herniations. Transforaminal endoscopic techniques for patients with symptomatic lumbar disc herniations have become increasingly popular. The literature has not yet been systematically reviewed. A comprehensive systematic literature search of the MEDLINE and EMBASE databases was performed up to May 2008. Two reviewers independently checked all retrieved titles and abstracts and relevant full text articles for inclusion criteria. Included articles were assessed for quality and outcomes were extracted by the two reviewers independently. One randomized controlled trial, 7 non-randomized controlled trials and 31 observational studies were identified. Studies were heterogeneous regarding patient selection, indications, operation techniques, follow-up period and outcome measures and the methodological quality of these studies was poor. The eight trials did not find any statistically significant differences in leg pain reduction between the transforaminal endoscopic surgery group (89%) and the open microdiscectomy group (87%); overall improvement (84 vs. 78%), re-operation rate (6.8 vs. 4.7%) and complication rate (1.5 vs. 1%), respectively. In conclusion, current evidence on the effectiveness of transforaminal endoscopic surgery is poor and does not provide valid information to either support or refute using this type of surgery in patients with symptomatic lumbar disc herniations. High-quality randomized controlled trials with sufficiently large sample sizes are direly needed to evaluate if transforaminal endoscopic surgery is more effective than open microdiscectomy. PMID:19756781

  13. [Use of glucocorticoids in low back pain due to disc herniation with radicular involvement].

    PubMed

    Lazarou, Ilias; Genevay, Stéphane; Nendaz, Mathieu

    2011-10-19

    Although systemic glucocorticoids are frequently used for the treatment of radicular pain due to disc herniation, there are only few studies available. No trial has successfully demonstrated the superiority of systemic glucocorticoids compared to placebo. Therefore their use is not recommended. Spinal injection using radiographic guidance appears to provide some beneficial short-term effect on pain. It might be offered when pain treatments according to the WHO steps have failed. Because rare but serious adverse events have been reported, transforaminal periradicular injections should only be used after thorough analysis of risks and benefits with the patient. PMID:22073701

  14. Recurrent lumbar disc herniation: A prospective comparative study of three surgical management procedures

    PubMed Central

    El Shazly, Ayman A.; El Wardany, Mohammed A.; Morsi, Ahmad M.

    2013-01-01

    Context: The optimal surgical treatment of recurrent lumbar disc herniation is controversial. Aim: To compare prospectively the clinical outcomes of surgical treatment of recurrent lumbar disc herniation by three different methods; discectomy alone, discectomy with transforaminal lumbar interbody fusion (TLIF), and diecectomy with posterolateral fusion (PLF), regardless of the postoperative radiological findings. Study Design: This is a prospective, randomized, comparative study. Materials and Methods: This is a prospective, randomized, comparative study on 45 patients with first time recurrent lumbar disc herniation. Patients were evaluated clinically by using the criteria of the Japanese Orthopedic Association's evaluation system for low back pain syndrome (JOA score). The patients were classified into three groups: Group A; patients who had revision discectomy alone, group B; patients who had revision discectomy with TLIF, and group C; patients who had revision discectomy with PLF. The mean follow-up period was 37 (±7.85 STD) months. Results: The mean overall recovery rate was 87.2% (±19.26 STD) and the satisfactory rate was 88.9%. Comparison between the three groups showed no significant difference with regard to the mean total postoperative JOA score, recovery rate, and satisfactory rate. However, the postoperative low back pain was significantly higher in group A than that of group B and C. Two patients in group A required further revision surgery. The incidences of dural tear and postoperative neurological deficit were higher in group A. The intraoperative blood loss and length of operation were significantly less in group A. The total cost of the procedure was significantly different between the three groups, being least in group A and highest in group B. There was no significant difference between the three groups with regard to the length of postoperative hospital stay. Conclusion: Revision discectomy is effective in patients with recurrent lumbar disc herniation. Fusion with revision discectomy improves the postoperative low back pain, decreases the intraoperative risk of dural tear or neural damage and decreases the postoperative incidence of mechanical instability or re-recurrence. TLIF and PLF have comparable results when used with revision discectomy, but PLF has significantly less total cost than TLIF. PMID:24403956

  15. Matrix metalloproteinase-7–dependent release of tumor necrosis factor-? in a model of herniated disc resorption

    PubMed Central

    Haro, Hirotaka; Crawford, Howard C.; Fingleton, Barbara; Shinomiya, Kenichi; Spengler, Dan M.; Matrisian, Lynn M.

    2000-01-01

    Herniated disc (HD), one of the major causes of low back pain, is often resolved spontaneously without surgical intervention. Resorption is associated with a marked increase in infiltrating macrophages, and the matrix metalloproteinases (MMP) MMP-3 and MMP-7 have been implicated in this phenomenon. We developed a murine organ culture model in which intact intervertebral discs were cocultured with peritoneal macrophages to investigate the role of MMPs in HD resorption. Using macrophages isolated from MMP-null mice, we report that macrophage-produced MMP-7 was required for proteoglycan degradation, loss of wet weight, and macrophage infiltration of cocultured discs. The inability of MMP-7–deficient macrophages to infiltrate discs could not be attributed to a defect in macrophage migration. MMP-7 was required for the release of the cytokine TNF-? from peritoneal macrophages. The generation of soluble TNF-? was essential for the induction of MMP-3 in disc cocultures, which in turn is required for the generation of a macrophage chemoattractant and subsequent macrophage infiltration. TNF-? release from macrophages was necessary but insufficient for disc resorption, which required macrophage infiltration. We conclude that there is extensive communication between macrophages and chondrocytes in HD resorption and that an essential component of this communication is the requirement for MMPs to release soluble bioactive factors. PMID:10642592

  16. Paraplegia after Gastrectomy in a Patient with Cervical Disc Herniation: A Case Report and Review of Literature

    PubMed Central

    Zhang, Qingfu; Jiang, Wei; Zhou, Quanhong; Wang, Guangyan; Zhao, Linlin

    2014-01-01

    Paraplegia is a rare postoperative complication. We present a case of acute paraplegia after elective gastrectomy surgery because of cervical disc herniation. The 73-year-old man has the medical history of cervical spondylitis with only symptom of temporary pain in neck and shoulder. Although the patient's neck was cautiously preserved by using the Discopo, an acute paraplegia emerged at about 10 hours after the operation. Severe compression of the spinal cord by herniation of the C4-C5 cervical disc was diagnosed and emergency surgical decompression was performed immediately. Unfortunately the patient showed limited improvement in neurologic deficits even after 11 months. PMID:24757571

  17. Thoracic Disc Herniation of the Adjacent Segment With Acutely Progressing Myelopathy

    PubMed Central

    Oh, In-Soo; Seo, Jun-Yeong; Kim, Yoon-Chung

    2010-01-01

    We report a case of a 66-year-old woman with progressing myelopathy. Her history revealed instrumented fusion from T10 to S1 for degenerative lumbar kyphosis and spinal stenosis. The plain radiographs showed narrowing of the intervertebral disc space with a gas shadow and sclerotic end-plate changes at T9-T10. Magnetic resonance imaging revealed a posterolateral mass compressing the spinal cord at the T9-T10 level. The patient was treated with a discectomy through the posterior approach combined with posterior instrumentation. The patient's symptoms and myelopathy resolved completely after the discectomy and instrumented fusion. The thoracic disc herniation might have been caused by the increased motion and stress concentration at the adjacent segment. PMID:20622956

  18. Co-existence of L5-S1 disc herniation and conus medullaris ependymoma

    PubMed Central

    Mino?lu, Mustafa; Akkol, ?smail; Özdemir, Nail; Y?ld?r?m, Levent

    2014-01-01

    INTRODUCTION The lumbar disc herniations are seen very common than spinal ependymomas in the neurosurgery polyclinic routine. PRESENTATION OF CASE In our case, both pathologies were seen at the most frequently located levels compatible with the literature. Aim of this case report is, to remind once more that, different pathologies can be found at the same time in a single patient; differential diagnosis must be done very carefully. DISCUSSION The routine Computed Tomography (CT) imaging for low back pain can not show the conus medullaris pathology. Spinal tumors or other similar pathologies should be kept in mind for differential diagnosis. A good medical history and a good physical examination must be completed before the final diagnosis. CONCLUSION Viewing of spinal canal with Magnetic Resonance Imaging (MRI) will be useful for the patients who we intend to do disc surgery. PMID:25460457

  19. Vertebral axial decompression therapy for pain associated with herniated or degenerated discs or facet syndrome: An outcome study

    Microsoft Academic Search

    Earl E. Gose; William K. Naguszewski; Robert K. Naguszewski

    The outcomes of vertebral axial decompression (DECOMPRESSION) therapy for patients with low back pain from various causes are reported. Data was collected from twenty-two medical centers for patients who received DECOMPRESSION therapy for low back pain, which was sometimes accompanied by referred leg pain. Only patients who received at least ten sessions and had a diagnosis of herniated disc, degenerative

  20. Minimally invasive far lateral microendoscopic discectomy for extraforaminal disc herniation at the lumbosacral junction: cadaveric dissection and technical case report

    Microsoft Academic Search

    John E. O'Toole; Kurt M. Eichholz; Richard G. Fessler

    2007-01-01

    Background contextExtraforaminal lumbar disc herniations (ELDHs) at the lumbosacral junction are an uncommon cause of L5 radiculopathy. The surgical anatomy of the extraforaminal space at L5–S1 is uniquely challenging for the various open surgical approaches that have been described for ELDHs in general. Reports specifically describing minimally invasive surgical approaches to lumbosacral ELDHs are lacking.

  1. Treatment of contained lumbar disc herniations using radiofrequency assisted micro-tubular decompression and nucleotomy: four year prospective study results

    PubMed Central

    2014-01-01

    Background Patients with radiculopathy caused by contained disc herniations are less likely to have good outcomes following discectomy surgery than patients with disc herniations that are not contained. The author presents his 4-year results from a prospective trial regarding the efficacy and safety of a tubular transforaminal radiofrequency-assisted manual decompression and annulus modulation of contained disc herniations in 58 patients. Methods Fifty-eight patients with lumbar radiculopathy due to a contained disc herniation were enrolled in a prospective clinical study. Visual analog scores (VAS) for back pain and leg pain, quality of life assessment, Macnab criteria, and SF-12 were collected from patients before treatment, at 2-years and 4-years post-treatment. Results At 4 years, results were obtained from 47 (81%) of patients. Compared to mean pre- treatment assessments, mean 4-year VAS for back pain improved from 8.6 to 2.3 points, and mean VAS for leg pain improved from 7.8 to 2.3. Eighty-three percent of respondents reported that they were “satisfied” or “very satisifed” with their quality of life at 4-years as per SF-12. At 4 years, recurrence was noted in 3 (6.4%) of respondents and no complications were reported. Conclusions The 2-year and 4-year study results are nearly identical, suggesting durable benefit out to 4 years. These results also suggest that in carefully selected patients with sustained contained disc herniations who have failed conservative treatments, manual decompression combined with radiofrequency-assisted decompression and annulus modulation are very likely to have good outcomes 4 years post-treatment. PMID:25694932

  2. Minimally invasive surgical procedures for the treatment of lumbar disc herniation

    PubMed Central

    Lühmann, Dagmar; Burkhardt-Hammer, Tatjana; Borowski, Cathleen; Raspe, Heiner

    2005-01-01

    Introduction In up to 30% of patients undergoing lumbar disc surgery for herniated or protruded discs outcomes are judged unfavourable. Over the last decades this problem has stimulated the development of a number of minimally-invasive operative procedures. The aim is to relieve pressure from compromised nerve roots by mechanically removing, dissolving or evaporating disc material while leaving bony structures and surrounding tissues as intact as possible. In Germany, there is hardly any utilisation data for these new procedures – data files from the statutory health insurances demonstrate that about 5% of all lumbar disc surgeries are performed using minimally-invasive techniques. Their real proportion is thought to be much higher because many procedures are offered by private hospitals and surgeries and are paid by private health insurers or patients themselves. So far no comprehensive assessment comparing efficacy, safety, effectiveness and cost-effectiveness of minimally-invasive lumbar disc surgery to standard procedures (microdiscectomy, open discectomy) which could serve as a basis for coverage decisions, has been published in Germany. Objective Against this background the aim of the following assessment is: Based on published scientific literature assess safety, efficacy and effectiveness of minimally-invasive lumbar disc surgery compared to standard procedures. To identify and critically appraise studies comparing costs and cost-effectiveness of minimally-invasive procedures to that of standard procedures. If necessary identify research and evaluation needs and point out regulative needs within the German health care system. The assessment focusses on procedures that are used in elective lumbar disc surgery as alternative treatment options to microdiscectomy or open discectomy. Chemonucleolysis, percutaneous manual discectomy, automated percutaneous lumbar discectomy, laserdiscectomy and endoscopic procedures accessing the disc by a posterolateral or posterior approach are included. Methods In order to assess safety, efficacy and effectiveness of minimally-invasive procedures as well as their economic implications systematic reviews of the literature are performed. A comprehensive search strategy is composed to search 23 electronic databases, among them MEDLINE, EMBASE and the Cochrane Library. Methodological quality of systematic reviews, HTA reports and primary research is assessed using checklists of the German Scientific Working Group for Health Technology Assessment. Quality and transparency of cost analyses are documented using the quality and transparency catalogues of the working group. Study results are summarised in a qualitative manner. Due to the limited number and the low methodological quality of the studies it is not possible to conduct metaanalyses. In addition to the results of controlled trials results of recent case series are introduced and discussed. Results The evidence-base to assess safety, efficacy and effectiveness of minimally-invasive lumbar disc surgery procedures is rather limited: Percutaneous manual discectomy: Six case series (four after 1998) Automated percutaneous lumbar discectomy: Two RCT (one discontinued), twelve case series (one after 1998) Chemonucleolysis: Five RCT, five non-randomised controlled trials, eleven case series Percutaneous laserdiscectomy: One non-randomised controlled trial, 13 case series (eight after 1998) Endoscopic procedures: Three RCT, 21 case series (17 after 1998) There are two economic analyses each retrieved for chemonucleolysis and automated percutaneous discectomy as well as one cost-minimisation analysis comparing costs of an endoscopic procedure to costs for open discectomy. Among all minimally-invasive procedures chemonucleolysis is the only of which efficacy may be judged on the basis of results from high quality randomised controlled trials (RCT). Study results suggest that the procedure maybe (cost)effectively used as an intermediate therapeutical option between conservative and operative management of small lumbar disc herniations

  3. The Influence of Obesity on the Outcome of Treatment of Lumbar Disc Herniation

    PubMed Central

    Rihn, Jeffrey A.; Kurd, Mark; Hilibrand, Alan S.; Lurie, Jon; Zhao, Wenyan; Albert, Todd; Weinstein, James

    2013-01-01

    Background: Questions remain as to the effect that obesity has on patients managed for symptomatic lumbar disc herniation. The purpose of this study was to determine if obesity affects outcomes following the treatment of symptomatic lumbar disc herniation. Methods: An as-treated analysis was performed on patients enrolled in the Spine Patient Outcomes Research Trial for the treatment of lumbar disc herniation. A comparison was made between patients with a body mass index of <30 kg/m2 (nonobese) (n = 854) and those with a body mass index of ?30 kg/m2 (obese) (n = 336). Baseline patient demographic and clinical characteristics were documented. Primary and secondary outcomes were measured at baseline and at regular follow-up time intervals up to four years. The difference in improvement from baseline between operative and nonoperative treatment was determined at each follow-up period for both groups. Results: At the time of the four-year follow-up evaluation, improvements over baseline in primary outcome measures were significantly less for obese patients as compared with nonobese patients in both the operative treatment group (Short Form-36 physical function, 37.3 compared with 47.7 points [p < 0.001], Short Form-36 bodily pain, 44.2 compared with 50.0 points [p = 0.005], and Oswestry Disability Index, ?33.7 compared with ?40.1 points [p < 0.001]) and the nonoperative treatment group (Short Form-36 physical function, 23.1 compared with 32.0 points [p < 0.001] and Oswestry Disability Index, ?21.4 compared with ?26.1 points [p < 0.001]). The one exception was that the change from baseline in terms of the Short Form-36 bodily pain score was statistically similar for obese and nonobese patients in the nonoperative treatment group (30.9 compared with 33.4 points [p = 0.39]). At the time of the four-year follow-up evaluation, when compared with nonobese patients who had been managed operatively, obese patients who had been managed operatively had significantly less improvement in the Sciatica Bothersomeness Index and the Low Back Pain Bothersomeness Index, but had no significant difference in patient satisfaction or self-rated improvement. In the present study, 77.5% of obese patients and 86.9% of nonobese patients who had been managed operatively were working a full or part-time job. No significant differences were observed in the secondary outcome measures between obese and nonobese patients who had been managed nonoperatively. The benefit of surgery over nonoperative treatment was not affected by body mass index. Conclusions: Obese patients realized less clinical benefit from both operative and nonoperative treatment of lumbar disc herniation. Surgery provided similar benefit over nonoperative treatment in obese and nonobese patients. Level of Evidence: Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence. PMID:23192403

  4. Detailed clinical characteristics of L1–2 disc herniation—a new classification and its features

    Microsoft Academic Search

    Koichiro Okuyama; Hiroshi Sasaki; Noriyuki Ishikawa; Tadato Kido; Hitoshi Suzuki; Mitsuho Chiba

    2011-01-01

    Background  It is no doubt that very rare incidence and anatomical complexity of L1\\/2 disc herniation are the main reasons for diagnostic\\u000a difficulty of disc hernia at the L1\\/2 level. The purpose of the current study is to propose a new classification of L1\\/2 disc\\u000a heniation and to reveal its specific neurosymptomatology.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  Between 1988 and 2010, we surgically treated 20 patients,

  5. Cervical myelopathy due to single level disc herniation presenting as intramedullary mass lesion: What to do first?

    PubMed

    Ek?i, Murat ?akir; Özcan Ek?i, Emel Ece; Y?lmaz, Baran; Tokta?, Zafer Orkun; Konya, Deniz

    2015-01-01

    Cervical myelopathy (CM) is mostly a degenerative process ending in myelopathic and/or radiculopathic syndromes. On T2-weighted magnetic resonance imaging (MRI), CM appears as a hyperintense area near the spondylotic spine. This high intensity signal depends on the impact of outer forces and their duration. It also determines the prognosis of the surgical candidate. A 40-year-old male patient admitted to our clinic with right upper extremity weakness and hypoesthesia that had started 2 months earlier. On neurological examination there was 2/5 motor weakness of right biceps brachii, and hypoesthesia over right C6 dermatome. Right upper extremity deep tendon reflexes were hypoactive, but lower ones were hyperactive. After clinical and radiological work-up, preliminary diagnosis was directed to a spinal intramedullary tumor. Total resection of the herniated cervical disc fragment and the mass lesion was managed. Pathology of the mass lesion was compatible with subacute infarct tissue and inflammatory response. Final diagnosis was CM under effect of cervical disc herniation. Contrast-enhanced spinal cord myelopathic lesions are very rare and resemble much more tumors and inflammatory processes. However, the principal treatment approach totally differs depending on pathology. When there are both a disc herniation and a high clinical suspicion; biopsy should be delayed. The most probable solution will be surgery for the disc disease with thorough preoperative scanning of vascular malformations; clinical and radiological close follow-up after surgery. Biopsy or surgical resection can be performed if patient deteriorates despite the primary surgery. PMID:25972718

  6. Risk factors for back pain-related loss of working time after surgery for lumbar disc herniation: a 5-year follow-up study

    Microsoft Academic Search

    K. Puolakka; J. Ylinen; M. H. Neva; H. Kautiainen; A. Häkkinen

    2008-01-01

    The aim of this study is to explore the occurrence and the risk factors of back-related loss of working time in patients undergoing\\u000a surgery for lumbar disc herniation. One hundred and fifty-two gainfully employed patients underwent surgery for lumbar disc\\u000a herniation. Two months postoperatively, those patients completed a self-report questionnaire including queries on back and\\u000a leg pain (VAS), functional capacity

  7. A review of current treatment for lumbar disc herniation in children and adolescents

    PubMed Central

    Liu, Zhongjun

    2009-01-01

    Lumbar disc herniation (LDH) is a common disorder among adults with degenerated lumbar intervertebral discs. However, its occurrence in childhood and adolescence is much less frequent mostly because children and adolescents tend to have a healthier lumbar spine as compared with adults. This difference indicates that children and adolescents are far from being just little adults. Over the years, there have constantly been published studies concerning this entity where the findings suggested that pediatric LDH is, in many ways, different from that in adults. To date, the prevalence, the etiological and the diagnostic features of pediatric LDH have been fully described in the literature whereas the characteristics regarding to the treatment is yet to be reviewed in details. The aim of the present review is to provide a collective opinion on the treatment of pediatric LDH as well as its outcome. It reviewed the relevant information available in the literature and compared the results among and within various treatments. It was found that pediatric patients responded less favorably to conservative treatment as compared with adults. In addition, the outcome of surgery remained to be satisfactory for at least 10 years after the initial operation, even though it appeared to deteriorate slightly. To the best of our knowledge, this is the first literature review focusing on the treatment of pediatric LDH. PMID:19890666

  8. Characteristics of lumbar disc herniation with exacerbation of presentation due to spinal manipulative therapy.

    PubMed

    Huang, Sheng-Li; Liu, Yan-Xi; Yuan, Guo-Lian; Zhang, Ji; Yan, Hong-Wei

    2015-03-01

    The aim of this article was to delineate the characteristics of lumbar disc herniation (LDH) in patients with exacerbation of symptoms caused by spinal manipulative therapy (SMT). The main emphasis should be on the prevention of this condition by identifying relevant risk factors. Detailed clinico-radiological profiles of a total number of 10 LDH patients with exacerbation of presentation after SMT were reviewed. All the patients underwent neurological and magnetic resonance imaging examinations. Laminectomy and discectomy were performed, and follow-up was carried out in all patients. The duration of symptoms in the patients before SMT was 4-15 years. After the therapy, an acute exacerbation of back and radicular pain was observed within 24?h. Magnetic resonance imaging showed that L4-L5 was the most frequently affected level observed (7 patients), and each patient had a large disc fragment in the spinal canal. The disc fragments were classified into 3 types according to their localizations. The time internal between the exacerbation of presentation and surgery was 23.1 days. No perioperative complications were noted. All the patients were relieved of radicular pain a few days after surgery. During postoperative follow-up, all patients regained the ability to walk; one patient received catheterization for 1 month and another for 6 months. Eight patients reported a complete resolution of presentation and the rest 2 patients were significantly improved. SMT should be prohibited in some LDH patients to prevent neurological damages, in whom there are 5 possible risk factors. Surgical results for these patients are encouraging. PMID:25816037

  9. Long-Term Outcome of Patients Suffering from Clinical Instability after Microsurgical Treatment of Lumbar Disc Herniation

    Microsoft Academic Search

    E. Kotilainen

    1998-01-01

    Summary   A total of 39 patients suffering from clinical instability of the lumbar spine after microdiscectomy were evaluated for\\u000a their long-term outcome. Included there were 21 (54%) male and 18(46%) female patients with a mean age of 55 years. All had\\u000a been operated on for a virgin single-level lumbar disc herniation between the years 1985–1989 and they were evaluated for

  10. The level-diagnosis of a lower lumbar disc herniation: The value of sensibility and motor testing

    Microsoft Academic Search

    O. H. Jensen

    1987-01-01

    Summary  Sensibility and motor power were prospectively tested in 52 consecutive hospitalized patients with a lower lumbar disc herniation,\\u000a verified by operation. The test results were noted in a decision matrix, and the positive and negative predictive values were\\u000a calculated. The positive predictive value of disturbed sensation in the L5 dermatome, paresis of dorsiflexion of the foot\\u000a and extension of the

  11. The role of matrix metalloproteinases and vascular endothelial growth factor in the resorption process of herniated disc

    Microsoft Academic Search

    Hirotaka Haro

    2002-01-01

    Purpose of study: Spontaneous resorption of herniated disc (HD) is frequently detected by magnetic resonance imaging. The tendency of HD to spontaneously resorb is directly proportional to the degree of Gd-DTPA enhancement suggesting a vascularization-mediated process that also correlates with prominent macrophage infiltration. Both infiltrating macrophages and factor VIII–positive cells were abundant in epidurally displaced HD, suggesting neovascularization process in

  12. Feasibility and Efficacy of Percutaneous Lateral Lumbar Discectomy in the Treatment of Patients with Lumbar Disc Herniation: A Preliminary Experience

    PubMed Central

    Jiang, Wenjin; Sun, Bolin; Sheng, Qirui; Song, Xuepeng; Zheng, Yanbo; Wang, Ligang

    2015-01-01

    Objective. This study was aimed at evaluating the effectiveness and safety of percutaneous lateral lumbar discectomy (PLLD) in treating patients with lumber disc herniation. Methods. A total of 183 patients with lumbar disc herniation were recruited to receive PLLD surgery from April 2006 to October 2011. All the adverse effects were recorded during the follow-up at 1, 3, 6, and 12 months after PLLD. The clinical outcomes were determined by visual analog scale and Japanese Orthopaedic Association score. Results. The surgery was performed successfully in all patients (102 males and 81 females aged from 21 to 66 years) with a mean 16.6-month follow-up (range from 26 to 65 months). No postoperative complications, including intestinal and vascular complications, nerve injuries, and postoperative infections, were associated with PLLD. At one month after surgery, visual analog scale (3.12±1.44 versus 6.76±2.31, P<0.05) was significantly lower than the baseline and was sustained until 24 months after surgery (3.25 ± 1.78 versus 6.76±2.31, P<0.05). Besides that, Japanese Orthopaedic Association score (25.25±3.21 versus 11.78±2.38, P<0.05) was increased when compared to the baseline. Conclusions. PLLD was a promising, mini-invasive, and effective treatment for lumber disc herniation. PMID:25695066

  13. Intradural schwannoma complicated by lumbar disc herniation at the same level: A case report and review of the literature

    PubMed Central

    BAEK, SEUNG-WOOK; KIM, CHEOL; CHANG, HAN

    2014-01-01

    Intradural tumours of the spine are usually benign and have a good prognosis, if they are diagnosed and removed early. Lumbar disc herniation is a common cause of chronic, acute, or recurrent lumbar radiculopathy. However, to date, there have been no reports of progressive neurological deficiencies due to the co-existence of two significant pathologies contributing to intradural and extradural compression. The current study reports the rare case of a patient with simultaneous extradural and intradural compression of the nerve root due to co-existent intervertebral disc herniation and an intradural schwannoma at the same level. A 71-year-old female suffering from lower back pain and radiating pain of the right lower extremities was admitted to Busan Korea Hospital (Busan, Korea). Magnetic resonance imaging revealed lumbar disc herniation at L4–5 and a mass occupying the intradural space at the same level of the compressed dural sac. Using the posterior approach, surgical excision of the two pathologies was performed. Pathological diagnosis confirmed schwannoma and the symptoms markedly improved. PMID:25013519

  14. Cervical Myelopathy Caused by Disc Herniation at the Segment of Existing Osteochondroma in a Patient with Hereditary Multiple Exostoses

    PubMed Central

    Tarukado, Kiyoshi; Senba, Hideyuki; Kitamura, Takahiro; Komiya, Norihiro; Shidahara, Satoshi

    2014-01-01

    Hereditary multiple exostoses (HME) is a benign hereditary disorder characterized by multiple osteochondromas. Osteochondroma appears occasionally in the spinal column as a part of HME. A 37-year-old man presented with a history of HME and cervical compressive myelopathy caused by intraspinal osteochondroma arising from the lamina of the C5 and disc herniation at the C5-6. He was treated by open-door laminoplasty at the C5 and C6 with excision of the tumor. The neurological symptoms were immediately relieved after surgery. Magnetic resonance images demonstrated a sufficient decompression of the spinal cord with a spontaneous regression of the herniated disc at one year after surgery. There was no recurrence of the tumor and no appearance of kyphosis and segmental instability of the cervical spine on postoperative imaging studies for three years after surgery. The patient could be successfully treated by laminoplasty with excision of the tumor and without removal of the herniated disc. PMID:25558330

  15. Comparison of Percutaneous Endoscopic Lumbar Discectomy and Open Lumbar Surgery for Adjacent Segment Degeneration and Recurrent Disc Herniation

    PubMed Central

    Chen, Huan-Chieh; Lee, Chih-Hsun; Wei, Li; Lui, Tai-Ngar; Lin, Tien-Jen

    2015-01-01

    Objective. The goal of the present study was to examine the clinical results of percutaneous endoscopic lumbar discectomy (PELD) and open lumbar surgery for patients with adjacent segment degeneration (ASD) and recurrence of disc herniation. Methods. From December 2011 to November 2013, we collected forty-three patients who underwent repeated lumbar surgery. These patients, either received PELD (18 patients) or repeated open lumbar surgery (25 patients), due to ASD or recurrence of disc herniation at L3-4, L4-5, or L5-S1 level, were assigned to different groups according to the surgical approaches. Clinical data were assessed and compared. Results. Mean blood loss was significantly less in the PELD group as compared to the open lumbar surgery group (P < 0.0001). Hospital stay and mean operating time were shorter significantly in the PELD group as compared to the open lumbar surgery group (P < 0.0001). Immediate postoperative pain improvement in VAS was 3.5 in the PELD group and ?0.56 in the open lumbar surgery group (P < 0.0001). Conclusion. For ASD and recurrent lumbar disc herniation, PELD had more advantages over open lumbar surgery in terms of reduced blood loss, shorter hospital stay, operating time, fewer complications, and less postoperative discomfort. PMID:25861474

  16. Prevalence of Lumbar Disc Herniation in Adolescent Males in Seoul, Korea: Prevalence of Adolescent LDH in Seoul, Korea

    PubMed Central

    Kim, Do-Keun; Oh, Chang Hyun; Lee, Myoung Seok; Park, Hyung-chun; Park, Chong Oon

    2011-01-01

    Objective The authors surveyed the prevalence and the clinical character of lumbar disc herniation (LDH) in Korean male adolescents, and the usefulness of current conscription criteria. Methods The data of 39,673 nineteen-year-old males that underwent a conscription examination at the Seoul Regional Korean Military Manpower Administration (MMA) from October 2010 to May 2011 were investigated. For those diagnosed as having lumbar disc herniation, prevalences, subject characteristics, herniation severities, levels of herniation, and modified Korean Oswestry low back pain disability scores by MMA physical grade were evaluated. The analysis was performed using medical certificates, medical records, medical images, and electromyographic and radiologic findings. Results The prevalence of adolescent LDH was 0.60%(237 of the 39,673 study subjects), and the prevalence of serious adolescent LDH with thecal sac compression or significant discogenic spinal stenosis was 0.28%(110 of the 39,673 study subjects). Of the 237 adolescent LDH cases, 105 (44.3%) were of single level LDH and 132 (55.7%) were of multiple level LDH, and the L4-5 level was the most severely and frequently affected. Oswestry back pain disability scores increased with herniation severity (p<0.01), and were well correlated with MMA grade. Conclusions In this large cohort of 19-year-old Korean males, the prevalence of adolescent LDH was 0.60% and the prevalence of serious adolescent LDH, which requires management, was relatively high at 0.28%. MMA physical grade was confirmed to be a useful measure of the disability caused by LDH.

  17. Therapeutic effects of Chinese osteopathy in patients with lumbar disc herniation.

    PubMed

    Zhang, Wei; Guo, Wei; Zhao, Ping; Zhou, Wei; Wei, Jie; Li, Xi-De; Liu, Liang

    2013-01-01

    A clinical study was conducted in 72 lumbar disc herniation (LDH) patients and 40 asymptomatic subjects to evaluate the efficacy of Feng's spinal manipulation (FSM). FSM was performed twice a week for less than 20 days. Changes in the symmetrical index of spinal column (SISC) and quantified symptom index (QSI) before and after FSM in both groups were collected. The QSI consisted of the visual analogue scale (VAS), score of the Japanese Orthopedic Association, and straight leg raising test, for measurement of pain perception, dysfunction of lower limb extension or flexion, and symptomatic relief. A correlation analysis was conducted to compare the difference in protruded nucleus pulposus size using computerized projection grating profilometry, SISC, and QSI before and after the therapy. The results showed that the SISC and QSI significantly decreased after treatment in the LDH group (p < 0.01). The SISC before and after treatment was closely correlated with the improvement of QSI, although there was no change in protruded nucleus pulposus following the therapy. Among the five components in SISC, the LR was found to be an ideal indicator for evaluation of the real circumstances in LDH patients. Our data suggested that FSM achieved satisfactory therapeutic effects in relieving the symptom of LDH while no effects were observed in asymptomatic subjects. PMID:24117063

  18. Postural control in patients with lumbar disc herniation in the early postoperative period

    PubMed Central

    Chantsoulis, Marzena; Kuczy?ski, Micha?

    2009-01-01

    Chronic spinal disc disease leads to disorders in postural movement coordination. An incorrect asymmetrical movement pattern for the lower limbs loading impairs proprioception and deteriorates postural stability, particularly when the vision is occluded. The standard surgical treatment improves biomechanical conditions in the lumbar spine, reduces pain, yet does it reduce the stability deficit in the upright position? An answer to the latter question would help work out targeted therapy to improve postural stability. We hypothesized that the standard surgical treatment would improve postural stability reflected by decreased sway variability accounting for better use of proprioceptive inputs postoperatively. Thirty-nine patients with lumbar disc herniation participated in the study. Their postural sway was recorded in anterior/posterior and medial/lateral planes with their eyes open or closed (EC) before and after surgery. The variability, range, mean velocity of the recorded time series and the area of the ellipse enclosed by the statokinesiogram were used as measures of postural stability. Preoperatively, EC condition resulted in an increased variability and mean velocity of postural sway, while postoperatively it caused an increase in sway mean velocity and sway area only with no effect on sway variability and range. The comparison of the balance before and after the surgery in the EC condition showed significant decrease in all parameters. In the early postoperative period, the patients recover the ability to control their postural sway in EC within normal limits, however, at the expense of significantly increased frequency of corrective torques. It is probably a transient short-term strategy needed to compensate for the recovery phase when the normal weighting factors for all afferents are being reestablished. We propose that this transient postoperative period may be the best timing of therapeutic intervention targeted at facilitating and reinforcing the acquisition of correct motor patterns. PMID:19562385

  19. Sequential dynamics of matrix metalloproteinases, tumor necrosis factor–?, vascular endothelial growth factor and plasmin expressions in the resorption process of herniated disc

    Microsoft Academic Search

    Tsuyoshi Kato; Hirotaka Haro; Hiromichi Komori; Kennichi Shinomiya

    2002-01-01

    Purpose of study: Granulation tissues of herniated disc (HD) are composed of marked infiltration macrophages and neovascularization that is not observed in the healthy intervertebral disc. Magnetic resonance imaging (MRI) study has shown that epidurally displaced HD tissues more commonly exhibited a gradual decrease in the size of HD. We previously showed that infiltrating macrophages, neovascularization induced by vascular endothelial

  20. Imaging of Herniated Discs of the Cervical Spine: Inter-Modality Differences between 64-Slice Multidetector CT and 1.5-T MRI

    PubMed Central

    Yi, Ji Sook; Han, Jong Kyu; Kim, Hyun-Joo

    2015-01-01

    Objective To assess inter-modality variability when evaluating cervical intervertebral disc herniation using 64-slice multidetector-row computed tomography (MDCT) and magnetic resonance imaging (MRI). Materials and Methods Three musculoskeletal radiologists independently reviewed cervical spine 1.5-T MRI and 64-slice MDCT data on C2-3 though C6-7 of 51 patients in the context of intervertebral disc herniation. Interobserver and inter-modality agreements were expressed as unweighted kappa values. Weighted kappa statistics were used to assess the extents of agreement in terms of the number of involved segments (NIS) in disc herniation and epicenter measurements collected using MDCT and MRI. Results The interobserver agreement rates upon evaluation of disc morphology by the three radiologists were in fair to moderate agreement (k = 0.39-0.53 for MDCT images; k = 0.45-0.56 for MRIs). When the disc morphology was categorized into two and four grades, the inter-modality agreement rates were moderate (k-value, 0.59) and substantial (k-value, 0.66), respectively. The inter-modality agreements for evaluations of the NIS (k-value, 0.78) and the epicenter (k-value, 0.79) were substantial. Also, the interobserver agreements for the NIS (CT; k-value, 0.85 and MRI; k-value, 0.88) and epicenter (CT; k-value, 0.74 and MRI; k-value, 0.70) evaluations by two readers were substantial. MDCT tended to underestimate the extent of herniated disc lesions compared with MRI. Conclusion Multidetector-row computed tomography and MRI showed a moderate-to-substantial degree of inter-modality agreement for the assessment of herniated cervical discs. MDCT images have a tendency to underestimate the anterior/posterior extent of the herniated disc compared with MRI. PMID:26175589

  1. Return to play after conservative treatment in athletes with symptomatic lumbar disc herniation: a practice-based observational study.

    PubMed

    Iwamoto, Jun; Sato, Yoshihiro; Takeda, Tsuyoshi; Matsumoto, Hideo

    2011-01-01

    The purpose of the study was to confirm the short-term outcome of conservative treatment in terms of the ability to return to play and factors influencing return to play in athletes with symptomatic lumbar disc herniation. A total of 100 consecutive athletes (72 male and 28 female) who consulted our sports medicine clinic during the 16-year period between September 1993 and October 2009 because of severe low back pain and/or leg pain/numbness due to lumbar disc herniation were studied. The mean age of the subjects was 23 years. All of them were conservatively treated by being advised to discontinue their sporting activities with/without short-term medication. After the subjective symptoms had reduced by more than 80%, individual training was started in order to allow the athletes to return to play. Seventy-nine athletes (79.0%) returned to play at an average of 4.8 months (range 1-12 months) after the start of treatment and were able to sustain the activities for at least 6 months, the minimum duration of follow-up in the study. The outcome of the conservative treatment was not influenced by the intensity of the sporting activity. Multiple logistic regression analyses showed that the severity of the symptoms prior to the start of treatment was the factor influencing the ability of the athletes to return to play. The present study confirmed the satisfactory short-term outcome of conservative treatment in athletes with symptomatic lumbar disc herniation regarding return to play and revealed that subjective symptoms prior to the start of treatment appeared to be a key factor in return to play after conservative treatment. PMID:24198567

  2. Translaminar Microendoscopic Herniotomy for Cranially Migrated Lumbar Disc Herniations Encroaching on the Exiting Nerve Root in the Preforaminal and Foraminal Zones

    PubMed Central

    Tono, Osamu; Senba, Hideyuki; Kitamura, Takahiro; Komiya, Norihiro; Oga, Masayoshi; Shidahara, Satoshi

    2013-01-01

    Study Design Case series. Purpose The aim of this study was to describe translaminar microendoscopic herniotomy (TL-MEH) for cranially migrated lumbar disc herniations encroaching on the exiting nerve root in the preforaminal and foraminal zones and to report preliminary results of the procedure. Overview of Literature Conventional interlaminar approaches for preforaminal and foraminal lumbar disc herniations result in extensive removal of the lamina and facet joint to remove disc fragments safely. More destructive approaches increase the risk of postoperative segmental instability. Methods TL-MEH is a minimally invasive procedure for herniotomy via the translaminar approach using a microendoscopic technique. TL-MEH was performed in seven patients with a cranially migrated lumbar disc herniation encroaching on the exiting nerve root. The disc fragments were located in the preforaminal zone in four patients, and in the preforaminal and foraminal zones in three. Results All patients experienced immediate relief from symptoms after surgery and satisfactory results at the final follow-up. Surgical complications, such as a dural tear, nerve injury, and surgical site infection, were not investigated. Conclusions TL-MEH seemed to be an effective and safe alternative minimally invasive surgical option for patients with a cranially migrated lumbar disc herniation encroaching the exiting nerve root in the preforaminal and foraminal zones. PMID:24066214

  3. Cost-effectiveness of microendoscopic discectomy versus conventional open discectomy in the treatment of lumbar disc herniation: a prospective randomised controlled trial [ISRCTN51857546

    PubMed Central

    Arts, Mark P; Peul, Wilco C; Brand, Ronald; Koes, Bart W; Thomeer, Ralph TWM

    2006-01-01

    Background Open discectomy is the standard surgical procedure in the treatment of patients with long-lasting sciatica caused by lumbar disc herniation. Minimally invasive approaches such as microendoscopic discectomy have gained attention in recent years. Reduced tissue trauma allows early ambulation, short hospital stay and quick resumption of daily activities. A comparative cost-effectiveness study has not been performed yet. We present the design of a randomised controlled trial on cost-effectiveness of microendoscopic discectomy versus conventional open discectomy in patients with lumbar disc herniation. Methods/Design Patients (age 18–70 years) presenting with sciatica due to lumbar disc herniation lasting more than 6–8 weeks are included. Patients with disc herniation larger than 1/3 of the spinal canal diameter, or disc herniation less than 1/3 of the spinal canal diameter with concomitant lateral recess stenosis or sequestration, are eliglible for participation. Randomisation into microendoscopic discectomy or conventional unilateral transflaval discectomy will take place in the operating room after induction of anesthesia. The length of skin incision is equal in both groups. The primary outcome measure is the functional assessment of the patient, measured by the Roland Disability Questionnaire for Sciatica, at 8 weeks and 1 year after surgery. We will also evaluate several other outcome parameters, including perceived recovery, leg and back pain, incidence of re-operations, complications, serum creatine kinase, quality of life, medical consumption, absenteeism and costs. The study is a randomised prospective multi-institutional trial, in which two surgical techniques are compared in a parallel group design. Patients and research nurses are kept blinded of the allocated treatment during the follow-up period of 2 years. Discussion Currently, open discectomy is the golden standard in the surgical treatment of lumbar disc herniation. Whether microendoscopic discectomy is more cost-effective than unilateral transflaval discectomy has to be determined by this trial. PMID:16696861

  4. Use of Magnetic Resonance Imaging to Identify Outcome Predictors of Caudal Epidural Steroid Injections for Lower Lumbar Radicular Pain Caused by a Herniated Disc

    PubMed Central

    Cha, Sung Oh; Jang, Chul Hoon; Hong, Jin Oh; Park, Joon Sang

    2014-01-01

    Objective We used lumbar magnetic resonance image (MRI) findings to determine possible outcome predictors of a caudal epidural steroid injection (CESI) for radicular pain caused by a herniated lumbar disc (HLD). Methods Ninety-one patients with radicular pain whose MRI indicated a HLD were enrolled between September 2010 and July 2013. The CESIs were performed using ultrasound (US). A responder was defined as having complete relief or at least a 50% reduction of pain as assessed by the visual analog scale (VAS) and functional status on the Roland Morris Disability Questionnaire (RMDQ); responder (VAS n=61, RMDQ n=51), and non-responder (VAS n=30, RMDQ n=40). MRI findings were analyzed and compared between the two groups with regard to HLD level, HLD type (protrusion or exclusion), HLD zone (central, subarticular, foraminal, and extraforaminal), HLD volume (mild, moderate, or severe), relationship between HLD and nerve root (no contact, contact, displaced, or compressed), disc height loss (none, less than half, or more than half ), and disc degeneration grade (homogeneous disc structure or inhomogeneous disc structure-clear nucleus and height of intervertebral disc). Results A centrally located herniated disc was more common in the responder group than that in the non-responder group. Treatment of centrally located herniated discs showed satisfactory results. (VAS p=0.025, RMDQ p=0.040). Other factors, such as HLD level, HLD type, HLD volume, relationship to nerve root, disc height loss, and disc degeneration grade, were not critical. Conclusion The HLD zone was significant for pain reduction after CESI. A centrally located herniated disc was a predictor of a good clinical outcome. PMID:25566478

  5. Fluoroscopic cervical epidural injections in chronic axial or disc-related neck pain without disc herniation, facet joint pain, or radiculitis

    PubMed Central

    Manchikanti, Laxmaiah; Cash, Kimberly A; Pampati, Vidyasagar; Malla, Yogesh

    2012-01-01

    Background While chronic neck pain is a common problem in the adult population, with a typical 12-month prevalence of 30%–50%, there is a lack of consensus regarding its causes and treatment. Despite limited evidence, cervical epidural injections are one of the commonly performed nonsurgical interventions in the management of chronic neck pain. Methods A randomized, double-blind, active, controlled trial was conducted to evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids for the management of chronic neck pain with or without upper extremity pain in patients without disc herniation, radiculitis, or facet joint pain. Results One hundred and twenty patients without disc herniation or radiculitis and negative for facet joint pain by means of controlled diagnostic medial branch blocks were randomly assigned to one of two treatment groups, ie, injection of local anesthetic only (group 1) or local anesthetic mixed with nonparticulate betamethasone (group 2). The primary outcome of significant pain relief and improvement in functional status (?50%) was demonstrated in 72% of group 1 and 68% of group 2. The overall average number of procedures per year was 3.6 in both groups with an average total relief per year of 37–39 weeks in the successful group over a period of 52 weeks. Conclusion Cervical interlaminar epidural injections of local anesthetic with or without steroids may be effective in patients with chronic function-limiting discogenic or axial pain. PMID:22826642

  6. Lumbar instrumented fusion compared with cognitive intervention and exercises in patients with chronic back pain after previous surgery for disc herniation: A prospective randomized controlled study

    Microsoft Academic Search

    Jens Ivar Brox; Olav Reikerås; Øystein Nygaard; Roger Sørensen; Aage Indahl; Inger Holm; Anne Keller; Tor Ingebrigtsen; Oliver Grundnes; Johan Emil Lange; Astrid Friis

    2006-01-01

    The effectiveness of lumbar fusion for chronic low back pain after surgery for disc herniation has not been evaluated in a randomized controlled trial. The aim of the present study was to compare the effectiveness of lumbar fusion with posterior transpedicular screws and cognitive intervention and exercises. Sixty patients aged 25–60 years with low back pain lasting longer than 1

  7. Reliability of the Path of the Sciatic Nerve, Congruence between Patients' History and Medical Imaging Evidence of Disc Herniation and Its Role in Surgical Decision Making

    PubMed Central

    Karimi Khouzani, Reza

    2015-01-01

    Study Design The prevalence of disc herniation is estimated to be about 100,000 new cases per year in France and disc herniation accounts for 25% to 30% of surgical activity in Departments of Neurosurgery. Classically, sciatica is expected to follow its specific dermatome-L5 or S1-. In clinical practice, we regularly encounter patients showing discrepancy between clinical sciatica and imaging findings. Purpose The aim of this paper is to review the medical concept and management of sciatica pain in patients showing this discrepancy. Overview of Literature To the best of our knowledge, this subject has not yet been discussed in the medical literature. Methods The medical records of 241 patients who were operated on for L5 or S1 sciatica caused by disc herniation were reviewed. Results We found an apparent clinicoradiological discrepancy between sciatica described by patients on one side and magnetic resonance imaging (MRI) finding on the other side in 27 (11.20%) patients. We did not find any other abnormalities in the preoperative and postoperative period. All of these patients underwent lumbar discectomy via posterior interlaminar approach. Three months after surgery, 25 patients (92.59%) had been totally relieved of sciatica pain. Two patients (7.41%) continued to experience sciatica in spite of the surgery. Conclusions The discrepancy between clinical sciatica and disc herniation level on MRI is not rare. Management of this discrepancy requires further investigation in order to avoid missing the diagnosis and treatment failure. PMID:25901230

  8. Physical therapy outcomes for patients receiving worker's compensation following treatment for herniated lumbar disc and mechanical low back pain syndrome.

    PubMed

    Di Fabio, R P; Mackey, G; Holte, J B

    1996-03-01

    Outcome of physical therapy for patients receiving workers' compensation may be related to a variety of factors, including the presence or absence of herniated lumbar intervertebral disc. The purpose of this study was to determine the level of disability, physical impairment, and rate of return-to-work for patients with disc disease and for those with mechanical low back pain syndrome without evidence of disc lesion. Twenty patients with disc disease and 22 patients with mechanical low back pain syndrome participated in this study. Physical therapy consisted of multiple interventions, including manual therapy based on the pattern of motion-provoked symptoms. The Oswestry disability questionnaire, fingertip-to-floor distance, and maximum pain-free isometric static lift were measured at the initial evaluation, 1 month following the initial assessment, and at discharge from the clinic. Patients with disc disease did not show significant improvement in the mean Oswestry score or in forward bending, but did show increased static lift capacity. In contrast, patients with mechanical low back pain syndrome had a significant reduction in disability and significant improvements in fingertip-to-floor distance and maximum pain-free isometric static lift. At the time of discharge, 90% of the patients followed with mechanical low back pain syndrome returned to work in some capacity compared with 45% of the patients followed with disc disease. A physical therapy program with multiple interventions that includes treatment based on the pattern of motion-provoked symptoms appears to have the greatest benefit for patients with mechanical low back pain syndrome. PMID:8919396

  9. Cytokine expression in the epidural space: a model of non-compressive disc herniation-induced inflammation

    PubMed Central

    Cuellar, Jason M.; Borges, Paula M.; Cuéllar, Vanessa Gabrovsky; Yoo, Andrew; Scuderi, Gaetano J.; Yeomans, David C.

    2012-01-01

    Study Design Animal study Objective Development of an animal model for the study of biochemical changes that occur in the epidural space after intervertebral disc herniation. Summary of Background Data Although strong evidence for an inflammatory component exists, the biochemical processes underlying pain following disc herniation remain unknown. Methods Epidural lavage was performed in 48 rats after L5 dorsal root ganglion (DRG) exposure at baseline and 3, 6, or 24 hours after placement of autologous nucleus pulposus (NP) (N = 15), saline (N = 15), or NP + an interferon-gamma antibody (anti-IFN?; N = 18) directly onto the DRG. Multiplex assays quantifying interleukin (IL-)-1-?, IL-1?, IL-2, IL-4, IL-6, IL-10, TNF?, IFN? and GM-CSF were performed. NP (N = 7) was also analyzed for these cytokines by placing NP into saline and measuring the relative concentration. Results Cytokines measured low at baseline (0–100pg/ml) in all groups. Compared to saline, NP application caused IL-6 elevation, peaking at T=3hr, that was prevented by anti-IFN?. NP induced elevation of TNF?, peaking at T=24hr and was prevented by anti-IFN?. IFN? was elevated after NP at T=3hr and T=24hr. IL-1? was similar after saline versus NP. The concentrations of IL-1? and IL-10 were elevated at T=3hr, 6hr and 24hr in all groups without between-groups difference. The level of IL-4 peaked at T=3hr in the NP group and was different than saline and NP +anti-IFN? groups but the time effect was insignificant. There was no change for GM-CSF. The concentration of cytokines measured in normal NP was < 2pg/ml for all cytokines except TNF?. Conclusion In this model of acute non-compressive disc herniation, NP caused the elevation of epidural IL-6, TNF? and IFN?; all attenuated by IFN? blockade. IL-1? and IL-10 were both significantly elevated by saline alone and their response was not prevented by IFN? blockade. This model may prove useful for the study of the biochemical processes by which NP induces inflammation-induced nerve root irritation and radiculopathic pain. PMID:22648034

  10. Minimally invasive surgery for synchronous, same-level lumbar intradural-extramedullary neoplasm and acute disc herniation.

    PubMed

    Tan, Lee A; Kasliwal, Manish K; Wewel, Joshua; Fontes, Ricardo B V; O'Toole, John E

    2014-09-01

    Schwannomas are the most common intradural-extramedullary spinal tumors, with an estimated incidence of 3 to 10 cases per 100,000 people. With continued advances in minimally invasive surgery (MIS) over recent years, MIS techniques have been utilized by spine surgeons in the resection of intradural spinal neoplasms with favorable surgical results and clinical outcomes. This video demonstrates a rare case of symptomatic, synchronous, same-level lumbar intradural-extramedullary neoplasm and acute disc herniation, both of which were successfully treated using a single MIS approach. Surgical pearls and nuances are discussed to better delineate technique and minimize potential complications. The video can be found here: http://youtu.be/78ibbicBRUk. PMID:25175577

  11. Percutaneous kyphoplasty for the treatment of osteoporotic thoracolumbar fractures with neurological deficit: radicular pain can mimic disc herniation

    PubMed Central

    Niu, Jun-Jie; Shen, Min-Jie; Meng, Bin; Yang, Yan; Yang, Hui-Lin

    2014-01-01

    Osteoporotic vertebral fractures (OVFs) are the common disease found in elderly population. Neurological deficit in OVFs is rare despite the involved posterior cortex of the fractured vertebral body, severe kyphotic deformity, or the instability at the fracture site. OVF with resulting neurological deficit was considered as a contraindication for vertebral augmentation techniques. We reported a rare case of a 75-year-old woman with L1, L2 osteoporotic vertebral fractures and L5/S1 disc herniation who presented with back pain and radicular pain extending along the posterior aspect of the left leg. Physical examination showed slight weakness of her flexor hallucis longus and absence of ankle jerk on her left leg. The result of a straight leg-raising test was limited to an angle of 50 degrees. The radiographs showed that the nerve root was compressed by the retropulsed bone fragment of the L2 vertebral body and a herniated disc at the level of L5/S1 on the left side. After L1 and L2 kyphoplasty the radicular pain as well as the back pain was completely disappeared. At her two-year follow-up examination, the patient was completely symptom free and reported no radicular pain. This case suggested that minimally invasive techniques such as kyphoplasty or vertebroplasty are effective in certain OVF patients with neurological deficit. Radicular pain could be caused by osteoporotic fracture that involves the posterior cortex of the vertebral body. Understanding the anatomy of nerve roots and pathogenetic mechanism of radicular pain is particularly important for treatment option. PMID:25232437

  12. Percutaneous kyphoplasty for the treatment of osteoporotic thoracolumbar fractures with neurological deficit: radicular pain can mimic disc herniation.

    PubMed

    Niu, Jun-Jie; Shen, Min-Jie; Meng, Bin; Yang, Yan; Yang, Hui-Lin

    2014-01-01

    Osteoporotic vertebral fractures (OVFs) are the common disease found in elderly population. Neurological deficit in OVFs is rare despite the involved posterior cortex of the fractured vertebral body, severe kyphotic deformity, or the instability at the fracture site. OVF with resulting neurological deficit was considered as a contraindication for vertebral augmentation techniques. We reported a rare case of a 75-year-old woman with L1, L2 osteoporotic vertebral fractures and L5/S1 disc herniation who presented with back pain and radicular pain extending along the posterior aspect of the left leg. Physical examination showed slight weakness of her flexor hallucis longus and absence of ankle jerk on her left leg. The result of a straight leg-raising test was limited to an angle of 50 degrees. The radiographs showed that the nerve root was compressed by the retropulsed bone fragment of the L2 vertebral body and a herniated disc at the level of L5/S1 on the left side. After L1 and L2 kyphoplasty the radicular pain as well as the back pain was completely disappeared. At her two-year follow-up examination, the patient was completely symptom free and reported no radicular pain. This case suggested that minimally invasive techniques such as kyphoplasty or vertebroplasty are effective in certain OVF patients with neurological deficit. Radicular pain could be caused by osteoporotic fracture that involves the posterior cortex of the vertebral body. Understanding the anatomy of nerve roots and pathogenetic mechanism of radicular pain is particularly important for treatment option. PMID:25232437

  13. Inpatient or Outpatient Rehabilitation after Herniated Disc Surgery? – Setting-Specific Preferences, Participation and Outcome of Rehabilitation

    PubMed Central

    Löbner, Margrit; Luppa, Melanie; Konnopka, Alexander; Meisel, Hans J.; Günther, Lutz; Meixensberger, Jürgen; Stengler, Katarina; Angermeyer, Matthias C.; König, Hans-Helmut; Riedel-Heller, Steffi G.

    2014-01-01

    Objective To examine rehabilitation preferences, participation and determinants for the choice of a certain rehabilitation setting (inpatient vs. outpatient) and setting-specific rehabilitation outcomes. Methods The longitudinal observational study referred to 534 consecutive disc surgery patients (18–55 years). Face-to-face baseline interviews took place about 3.6 days after disc surgery during acute hospital stay. 486 patients also participated in a follow-up interview via telephone three months later (dropout-rate: 9%). The following instruments were used: depression and anxiety (Hospital Anxiety and Depression Scale), pain intensity (numeric analog scale), health-related quality of life (Short Form 36 Health Survey), subjective prognosis of gainful employment (SPE-scale) as well as questions on rehabilitation attendance, return to work, and amount of sick leave days. Results The vast majority of patients undergoing surgery for a herniated disc attended a post-hospital rehabilitation treatment program (93%). Thereby two-thirds of these patients took part in an inpatient rehabilitation program (67.9%). Physical, psychological, vocational and health-related quality of life characteristics differed widely before as well as after rehabilitation depending on the setting. Inpatient rehabilitees were significantly older, reported more pain, worse physical quality of life, more anxiety and depression and a worse subjective prognosis of gainful employment before rehabilitation. Pre-rehabilitation differences remained significant after rehabilitation. More than half of the outpatient rehabilitees (56%) compared to only one third of the inpatient rehabilitees (33%) returned to work three months after disc surgery (p<.001). Conclusion The results suggest a “pre-selection” of patients with better health status in outpatient rehabilitation. Gaining better knowledge about setting-specific selection processes may help optimizing rehabilitation allocation procedures and improve rehabilitation effects such as return to work. PMID:24598904

  14. Higher preoperative Oswestry Disability Index is associated with better surgical outcome in upper lumbar disc herniations

    Microsoft Academic Search

    Hooshang Saberi; Arash Vatankhahan Isfahani

    2008-01-01

    To evaluate the surgical outcome in terms of functional and subjective recovery, patients who needed discectomies at L1–L2,\\u000a L2–L3 and L3–L4 levels were compared with an age and sex-matched group of patients who required L4–L5 and L5–S1 discectomies.\\u000a We prospectively enrolled 50 consecutive patients, referred to our center, who had L1–L2, L2–L3 and L3–L4 herniations and\\u000a required surgical intervention. Likewise,

  15. Fragmentectomy versus Conventional Microdiscectomy in Single-Level Lumbar Disc Herniations : Comparison of Clinical Results and Recurrence Rates

    PubMed Central

    Kim, Yeon-Seong; Lee, Min-Cheol; Song, Jae-Wook; Kim, Sang-Kyu; Kim, In-Hwan

    2012-01-01

    Objective This retrospective study aimed to compare clinical outcomes in terms of pain relief and recurrence rate between fragmentectomies and conventional microdiscectomies in patients with lumbar disc herniation (LDH). Methods Between January 2008 and May 2011, a total of 175 patients met the inclusion criteria of this study. The visual analogue scale (VAS) scores of back and radicular pains were recorded before surgery, 2 and 6 weeks after surgery. Recurrence was defined when a patient had the same pattern of preoperative symptoms and was confirmed with magnetic resonance imaging. Results Seventy-four patients (42.3%) were suitable for fragmentectomy, and 101 patients underwent conventional microdiscectomy. There were no significant differences in VAS scores between the fragmentectomy and conventional microdiscectomy groups 2 and 6 weeks after surgery. During the follow-up period, 3 patients (4.05%) in the fragmentectomy group and 7 patients (6.93%) in the conventional microdiscectomy group relapsed. Conclusion If patients are selected according to well-defined criteria, fragmentectomy can be a good surgical option for LDH, in the physiological aspect of preserving healthy intervertebral disc materials. PMID:23115663

  16. The influence of torsion on disc herniation when combined with flexion

    Microsoft Academic Search

    Samuel P. VeresPeter; Peter A. Robertson; Neil D. Broom

    2010-01-01

    The role of torsion in the mechanical derangement of intervertebral discs remains largely undefined. The current study sought\\u000a to investigate if torsion, when applied in combination with flexion, affects the internal failure mechanics of the disc wall\\u000a when exposed to high nuclear pressure. Thirty ovine lumbar motion segments were each positioned in 2° axial rotation plus\\u000a 7° flexion. Whilst maintained

  17. The prognostic value of cerebrospinal fluid characteristics in dogs without deep pain perception due to thoracolumbar disc herniation.

    PubMed

    Chamisha, Y; Aroch, I; Kuzi, S; Srugo, I; Bdolah-Abram, T; Chai, O; Christopher, M M; Merbl, Y; Rothwell, K; Shamir, M H

    2015-06-01

    Providing a pre-operative prognosis for dogs presented with absent deep pain perception (DPP) is extremely challenging, as the overall recovery rates widely vary. This study assesses the possible correlation between the severity of spinal cord injury and CSF cytology in 31 paraplegic dogs presented with absent DPP due to acute thoracolumbar intervertebral disc herniation (TL-IVDH). All dogs underwent surgical decompression immediately following diagnosis. CSF TNCC, macrophage percentage and macrophage to monocyte (M?:M) ratio were significantly higher in dogs that failed to regain DPP within 10 days post-operatively and in dogs that failed to regain ambulation at the end of the study period (P

  18. Lateral transmuscular or combined interlaminar/paraisthmic approach to lateral lumbar disc herniation? A comparative clinical series of 48 patients

    PubMed Central

    Ryang, Y; Rohde, I; Ince, A; Oertel, M; Gilsbach, J; Rohde, V

    2005-01-01

    Background: The optimum operative technique for lateral lumbar disc herniations (LLDH) remains unclear, and both interlaminar and extraspinal approaches are used. Objective: To compare outcome after LLDH removal either by a lateral transmuscular approach (LTM) or by a combined interlaminar and paraisthmic approach (CIP). Methods: 28 patients underwent surgery using CIP and 20 using LTM. All patients were operated on by the same neurosurgeon. The clinical presentation of the two groups was comparable. Overall outcome was assessed after a mean follow up period of between 19 and 37 months using the Ebeling classification. In addition, the effect of surgery on radicular pain, low back pain, and sensory and motor deficits was defined. Results: Excellent to good results were achieved in 95% of the LTM group and 57% of the CIP group. The outcome was satisfactory to poor in 5% of the LTM and 43% of the CIP group (p<0.004). The percentage of sensorimotor deficit and of radicular pain improvement was higher in the LTM group. New low back pain was found exclusively in the CIP group (21%). The complication rate was 5% in the LTM group and 11% in the CIP group. Conclusions: The LTM approach achieves a better overall outcome and improvement in radiculopathy. The complication rate is lower with the transmuscular route and the risk of new low back pain is minimised. These results are likely to be attributable at least in part to the lesser invasiveness of the LTM approach. PMID:15965204

  19. Assessing the Effect of Spaceflight on the Propensity for Astronauts to Develop Disc Herniation

    NASA Technical Reports Server (NTRS)

    Feiveson, A.; Mendez, C.; Somers, J.

    2015-01-01

    A previous study reported that the instantaneous risk of developing a Herniated Nucleus Pulposus (HNP) was higher in astronauts who had flown at least one mission, as compared with those in the corps who had not yet flown. However, the study only analyzed time to HNP after the first mission (if any) and did not account for the possible effects of multiple missions. While many HNPs occurred well into astronauts' careers or in somecases years after retirement, the higher incidence of HNPs relatively soon after completion of space missions appears to indicate that spaceflight may lead to an increased risk of HNP. In addition, when an HNP occurs after spaceflight, is it related to previous spaceflight exposure? The purpose of this study was to investigate whether multiple missions, sex, age, vehicle landing dynamics, and flight duration affect the risk of developing an HNP usinga competing risks model. The outcome of the study will inform the Human System Risk Board assessment of back pain, inform the risk of injury due to dynamic loads, and update the previous dataset, which contained events up to December 31, 2006.

  20. Postural control in patients with lumbar disc herniation in the early postoperative period

    Microsoft Academic Search

    Tomasz Sipko; Marzena Chantsoulis; Micha? Kuczy?ski

    2010-01-01

    Chronic spinal disc disease leads to disorders in postural movement coordination. An incorrect asymmetrical movement pattern\\u000a for the lower limbs loading impairs proprioception and deteriorates postural stability, particularly when the vision is occluded.\\u000a The standard surgical treatment improves biomechanical conditions in the lumbar spine, reduces pain, yet does it reduce the\\u000a stability deficit in the upright position? An answer to

  1. Affective, anxiety, and substance-related disorders in patients undergoing herniated disc surgery

    Microsoft Academic Search

    Margrit ZiegerMelanie; Melanie Luppa; Herbert Matschinger; Hans J. Meisel; Lutz Günther; Jürgen Meixensberger; René Toussaint; Matthias C. Angermeyer; Hans-Helmut König; Steffi G. Riedel-Heller

    Purpose  At present only a small number of studies have investigated psychiatric comorbidity in disc surgery patients. Objectives of\\u000a this study are (1) to examine the prevalence rate of comorbid affective, anxiety, and substance-related disorders in nucleotomy\\u000a patients in comparison to the German general population and (2) to investigate associations between psychiatric comorbidity\\u000a and socio-demographic and illness-related characteristics.\\u000a \\u000a \\u000a \\u000a \\u000a Methods  The study refers

  2. The Impact of Workers' Compensation on Outcomes of Surgical and Nonoperative Therapy for Patients with a Lumbar Disc Herniation SPORT

    PubMed Central

    Atlas, Steven J.; Tosteson, Tor D.; Blood, Emily A.; Skinner, Jonathan S.; Pransky, Glenn S.; Weinstein, James N.

    2010-01-01

    Study Design Prospective randomized and observational cohorts. Objective To compare outcomes of patients with and without workers' compensation who had surgical and nonoperative treatment for a lumbar intervertebral disc herniation (IDH). Summary of Background Data Few studies have examined the association between worker's compensation and outcomes of surgical and nonoperative treatment. Methods Patients with at least 6 weeks of sciatica and a lumbar IDH were enrolled in either a randomized trial or observational cohort at 13 US spine centers. Patients were categorized as workers' compensation or nonworkers' compensation based on baseline disability compensation and work status. Treatment was usual nonoperative care or surgical discectomy. Outcomes included pain, functional impairment, satisfaction and work/disability status at 6 weeks, 3, 6, 12, and 24 months. Results Combining randomized and observational cohorts, 113 patients with workers' compensation and 811 patients without were followed for 2 years. There were significant improvements in pain, function, and satisfaction with both surgical and nonoperative treatment in both groups. In the nonworkers' compensation group, there was a clinically and statistically significant advantage for surgery at 3 months that remained significant at 2 years. However, in the workers' compensation group, the benefit of surgery diminished with time; at 2 years no significant advantage was seen for surgery in any outcome (treatment difference for SF-36 bodily pain [?5.9; 95% CI: ?16.7–4.9] and physical function [5.0; 95% CI: ?4.9–15]). Surgical treatment was not associated with better work or disability outcomes in either group. Conclusion Patients with a lumbar IDH improved substantially with both surgical and nonoperative treatment. However, there was no added benefit associated with surgical treatment for patients with workers' compensation at 2 years while those in the nonworkers' compensation group had significantly greater improvement with surgical treatment. PMID:20023603

  3. Surgical versus Non-Operative Treatment for Lumbar Disc Herniation: Four-Year Results for the Spine Patient Outcomes Research Trial (SPORT)

    PubMed Central

    Weinstein, James N.; Lurie, Jon D.; Tosteson, Tor D.; Tosteson, Anna N. A.; Blood, Emily; Abdu, William A.; Herkowitz, Harry; Hilibrand, Alan; Albert, Todd; Fischgrund, Jeffrey

    2009-01-01

    Study Design Concurrent prospective randomized and observational cohort study. Objectives To assess the 4-year outcomes of surgery vs. non-operative care. Background Although randomized trials have demonstrated small short-term differences in favor of surgery, long-term outcomes comparing surgical to non-operative treatment remain controversial. Methods Surgical candidates with imaging-confirmed lumbar intervertebral disc herniation meeting SPORT eligibility criteria enrolled into prospective randomized (501 participants) and observational cohorts (743 participants) at 13 spine clinics in 11 US states. Interventions were standard open discectomy versus usual non-operative care. Main outcome measures were changes from baseline in the SF-36 Bodily Pain (BP) and Physical Function (PF) scales and the modified Oswestry Disability Index (ODI - AAOS/Modems version) assessed at 6 weeks, 3 and 6 months, and annually thereafter. Results Non-adherence to treatment assignment caused the intent-to-treat analyses to underestimate the treatment effects. In the 4-year combined as-treated analysis, those receiving surgery demonstrated significantly greater improvement in all the primary outcome measures (mean change Surgery vs. Non-operative; treatment effect; 95% CI): BP (45.6 vs. 30.7; 15.0; 11.8 to 18.1), PF (44.6 vs. 29.7; 14.9; 12.0 to 17.8) and ODI (?38.1 vs. ?24.9; ?13.2; ?15.6 to ?10.9). The percent working was similar between the surgery and non-operative groups, 84.4% vs. 78.4% respectively. Conclusion In a combined as-treated analysis at 4 years, patients who underwent surgery for a lumbar disc herniation achieved greater improvement than non-operatively treated patients in all primary and secondary outcomes except work status. Trial Registration Spine Patient Outcomes Research Trial (SPORT): Intervertebral Disc Herniation; #NCT00000410; http://www.clinicaltrials.gov/ct/show/NCT00000410?order=2 PMID:19018250

  4. The NEtherlands Cervical Kinematics (NECK) Trial. Cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in the treatment of cervical disc herniation; a double-blind randomised multicenter study

    PubMed Central

    2010-01-01

    Background Patients with cervical radicular syndrome due to disc herniation refractory to conservative treatment are offered surgical treatment. Anterior cervical discectomy is the standard procedure, often in combination with interbody fusion. Accelerated adjacent disc degeneration is a known entity on the long term. Recently, cervical disc prostheses are developed to maintain motion and possibly reduce the incidence of adjacent disc degeneration. A comparative cost-effectiveness study focused on adjacent segment degeneration and functional outcome has not been performed yet. We present the design of the NECK trial, a randomised study on cost-effectiveness of anterior cervical discectomy with or without interbody fusion and arthroplasty in patients with cervical disc herniation. Methods/Design Patients (age 18-65 years) presenting with radicular signs due to single level cervical disc herniation lasting more than 8 weeks are included. Patients will be randomised into 3 groups: anterior discectomy only, anterior discectomy with interbody fusion, and anterior discectomy with disc prosthesis. The primary outcome measure is symptomatic adjacent disc degeneration at 2 and 5 years after surgery. Other outcome parameters will be the Neck Disability Index, perceived recovery, arm and neck pain, complications, re-operations, quality of life, job satisfaction, anxiety and depression assessment, medical consumption, absenteeism, and costs. The study is a randomised prospective multicenter trial, in which 3 surgical techniques are compared in a parallel group design. Patients and research nurses will be kept blinded of the allocated treatment for 2 years. The follow-up period is 5 years. Discussion Currently, anterior cervical discectomy with fusion is the golden standard in the surgical treatment of cervical disc herniation. Whether additional interbody fusion or disc prothesis is necessary and cost-effective will be determined by this trial. Trial Registration Netherlands Trial Register NTR1289 PMID:20553591

  5. Influences of spinal decompression therapy and general traction therapy on the pain, disability, and straight leg raising of patients with intervertebral disc herniation.

    PubMed

    Choi, Jioun; Lee, Sangyong; Hwangbo, Gak

    2015-02-01

    [Purpose] The purpose of this study was to identify how spinal decompression therapy and general traction therapy influence the pain, disability, and straight leg raise (SLR) ability of patients with intervertebral disc herniation. [Subjects] The subjects were 30 patients with chronic lumbar pain who were divided into a spinal decompression therapy group (SDTG, n=15), and a general traction therapy group (GTTG, n=15). [Methods] The SDTG used a spinal decompression device, and the GTTG used a lumbar traction device. Both groups received conservative physical therapy three times a week for four weeks. A visual analog scale (VAS) was used to measure the degree of pain the patients with chronic lumbar pain. The Oswestry Disability Index (ODI) was used to measure the degree of functional disability. A goniometer was used to measure the patients' SLR ability. [Results] Both SDTG and GTTG showed statistically significant decreases in VAS and ODI scores and a statistically significant increase in SLR angle. A comparison of the two groups found no statistically significant differences. [Conclusion] Spinal decompression therapy and general traction therapy are effective at improving the pain, disability, and SLR of patients with intervertebral disc herniation. Thus, selective treatment may be required. PMID:25729196

  6. Local Irrigation of the Surgical Field with Antibiotics in the End of Procedure Reduces the Infection Rate in Herniated Lumbar Disc Surgery

    PubMed Central

    Kërveshi, Armend; Halili, Nehat; Kastrati, Bujar; Qosja, Faik; Kabashi, Serbeze; Muçaj, Sefedin

    2014-01-01

    Introduction: Reported rate of infections after lumbar discectomy is 1%–15 %. This complication may result in disability or even the death. Aim The aim of the study is to assess the rate of infection associated with lumbar discectomies when combined systemic and local antibiotic prophylaxis was employed. Patients and methods: In this retrospective study we analyzed all patients operated for herniated lumbar disc from 2009 -2012 in our institute. Beside of receiving systemic prophylaxis with 2g of Cefazoline, all patients had their operative field irrigated at the end of operation with Amikacin sulfate injection. Wound was considered infected when local and systemic signs of infection were revealed and were associated with elevated ESR, leukocytosis and elevated CRP. Assessment of infection is done by neurosurgeon during the hospitalization and later at outpatient’s clinic along postoperative course of three months. Results: A total of 604 patients were operated, of those 285 patients (47.2 %) females and 319 males (52.8 %), 12 patients were operated on two levels (1.98 %). Average patient age was 32.5 years (range 20–65 years) Localization of herniated disc was: in L/2-L/3 20 patients or 3.3 %, the L/3-L/4 level 42 patients or 7 % , the L/4 -L /5 262 patients or 43.3 % at the level L/V- S/1 280 patients or 46.3 %. Three patients (0.49%) developed wound infection, two of them superficial infection only with local signs: local pain, redness and leakage. They were treated with oral antibiotics. One with deep wound infection. He presented with local and systemic signs and treated with i.v antibiotics. All the cultures from wound swab revealed staphylococcus aureus. Conclusion: Prophylaxis with systemic antibiotic (Cefazoline 2.0) intravenous administration 30 minutes before the incision and irrigation of operative field with local antibiotic Amikacine sulfate at the end of procedure reduces the infection rate in patients operated for herniated lumbar disc when compared with systemic antibiotic prophylaxis only. PMID:25685087

  7. Diffusion-Weighted Imaging for Pretreatment Evaluation and Prediction of Treatment Effect in Patients Undergoing CT-Guided Injection for Lumbar Disc Herniation

    PubMed Central

    Niu, Xiang-Ke; Bhetuwal, Anup

    2015-01-01

    Objective To determine whether a change in apparent diffusion coefficient (ADC) value could predict early response to CT-guided Oxygen-Ozone (O2-O3) injection therapy in patients with unilateral mono-radiculopathy due to lumbar disc herniation. Materials and Methods A total of 52 patients with unilateral mono-radiculopathy received a single intradiscal (3 mL) and periganglionic (5 mL) injection of an O2-O3 mixture. An ADC index of the involved side to the intact side was calculated using the following formula: pre-treatment ADC index = ([ADC involved side - ADC intact side] / ADC intact side) × 100. We analyzed the relationship between the pre-treatment Oswestry Disability Index (ODI) and the ADC index. In addition, the correlation between ODI recovery ratio and ADC index was investigated. The sensitivity and specificity of the ADC index for predicting response in O2-O3 therapy was determined. Results Oswestry Disability Index and the ADC index was not significantly correlated (r = -0.125, p = 0.093). The ADC index and ODI recovery ratio was significantly correlated (r = 0.819, p < 0.001). When using 7.10 as the cut-off value, the ADC index obtained a sensitivity of 86.3% and a specificity of 82.9% for predicting successful response to therapy around the first month of follow-up. Conclusion This preliminary study demonstrates that the patients with decreased ADC index tend to show poor improvement of clinical symptoms. The ADC index may be a useful indicator to predict early response to CT-guided O2-O3 injection therapy in patients with unilateral mono-radiculopathy due to lumbar disc herniation.

  8. Plasma metabonomic profiling of lumbar disc herniation and its traditional Chinese medicine subtypes in patients by using gas chromatography coupled with mass spectrometry.

    PubMed

    Shan, Letian; Liao, Fei; Jin, Hongting; Ye, Fusheng; Tong, Peijian; Xiao, Luwei; Zhou, Jia; Wu, Chengliang

    2014-11-01

    Lumbar disc herniation (LDH) is a commonly occurring disease, threatening human health and life quality. Lack of a gold standard of diagnosis has hindered the efficiency and efficacy of clinical therapy against LDH. Traditional Chinese medicine (TCM) has provided an experience-based but subjective diagnosis system for LDH, demanding objective evidence and explanation. In this study, we adopted a metabonomics approach using gas chromatography-mass spectrometry (GC-MS) to profile metabolic characteristics of LDH and its TCM subtypes. Plasma samples of 41 LDH patients and 25 healthy controls were collected. LDH patients were classified into two main subtypes, the reality syndrome and deficiency syndrome, according to TCM theory. By using multivariate statistical analysis and metabolism network analysis, we found diverse perturbations of metabolites in amino acid metabolism and carbohydrate metabolism, in which the amino acids (glutamic acid, aspartic acid, glycine, etc.) were up-regulated and a key carbohydrate metabolite (glucose 1-phosphate) was down-regulated. Few differences were found between the two TCM subtypes. Our findings reveal the metabolic disorders of LDH for the first time and demonstrate the feasibility of the metabonomics approach for LDH research but not for its TCM subtypes. PMID:25144444

  9. Variation in eligibility criteria from studies of radiculopathy due to a herniated disc and of neurogenic claudication due to lumbar spinal stenosis: A structured literature review

    PubMed Central

    Genevay, S.; Atlas, S.J.; Katz, J.N.

    2009-01-01

    Study Design A structured literature review. Summary of the Background Data Widely recognized classification criteria for rheumatologic disorders have resulted in well-defined patient populations for clinical investigation. Objectives We sought to determine whether similar criteria were needed for back pain disorders by examining variability in eligibility criteria in published studies Methods Studies involving radiculopathy due to lumbar herniated disc (HD) and for neurogenic claudication due to lumbar spinal stenosis (LSS) were identified. Randomized controlled trials published between January 1, 2006 and October 1, 2008 in select peer reviewed journals were retrieved, their eligibility criteria were identified and categorized. Results Twelve eligible HD studies were identified. Thirteen unique categories of eligibility criteria were identified with a mean of 3.9 (+/?2.0) and a range from 0 to 8 categories per study. More categories were present for studies that included nonsurgical (5.6 +/? 2.5) treatment for studies with only surgical treatment (2.6 +/? 1.7) p= 0.04). Seven LSS studies met eligibility criteria, and 9 unique categories were identified. A mean of 5.0 (+/?2.2) categories with a range from 2 to 7 was used per study. Conclusion Wide variation in the number and type of eligibility criteria from randomized clinical trials of well defined back pain syndromes was identified. These results support the need for developing and disseminating international classification criteria for these clinical conditions. PMID:20228710

  10. Combination of serum phosphorylated neurofilament heavy subunit and hyperintensity of intramedullary T2W on magnetic resonance imaging provides better prognostic value of canine thoracolumbar intervertebral disc herniation.

    PubMed

    Mashita, Tadahisa; Kamishina, Hiroaki; Nakamoto, Yuya; Akagi, Yosuke; Nakanishi, Ataru; Harasaki, Yusuke; Ozawa, Tsuyoshi; Uemura, Takashi; Kobatake, Yui; Shimamura, Shunsuke; Kitamura, Naoki; Maeda, Sadatoshi; Uzuka, Yuji; Shaw, Gerry; Yasuda, Jun

    2015-04-01

    The aim of this study was to evaluate the prognostic value of concurrent measurement of serum phosphorylated neurofilament heavy subunit (pNF-H) concentration and intramedullary T2W hyperintensity in paraplegic to paraplegic dogs. Our hypothesis was that concurrent measurement of these would provide a more accurate prediction of functional outcome in dogs with thoracolumbar intervertebral disc herniation (IVDH). A prospective case-control clinical study was designed using 94 dogs with acute onset of thoracolumbar IVDH. The association of serum pNF-H concentration, T2W hyperintensity on sagittal MRI (T2H/L2), deep pain perception and surgical outcome were evaluated with logistic regression analysis after three months for all 94 surgically treated dogs. Sensitivity to predict non-ambulatory outcome was compared among pNF-H and T2H/L2 and combination of both. Logistic regression analysis indicated that serum pNF-H concentration and T2H/L2 were significantly correlated with surgical outcome (P<0.05); however, deep pain perception was not (P=0.41). The results of logistic regression analysis indicated that the odds ratios of unsuccessful long-term outcome were 2.6 for serum pNF-H concentration, 1.9 for T2H/L2 and 2.3 for deep pain sensation. The sensitivity and specificity to predict non-ambulatory outcome for using serum parameter pNF-H>2.6 ng/ml, using T2H/L2 value of>0.84 and using both serum pNF-H and T2H/L2, were 95% and 75.7%, 65% and 86.5%, and 90.0% and 97.5%, respectively. Therefore, combined measurements of serum pNF-H and T2H/L2 might be useful for predicting long-term outcome in dogs with thoracolumbar IVDH. PMID:25650056

  11. Combination of serum phosphorylated neurofilament heavy subunit and hyperintensity of intramedullary T2W on magnetic resonance imaging provides better prognostic value of canine thoracolumbar intervertebral disc herniation

    PubMed Central

    MASHITA, Tadahisa; KAMISHINA, Hiroaki; NAKAMOTO, Yuya; AKAGI, Yosuke; NAKANISHI, Ataru; HARASAKI, Yusuke; OZAWA, Tsuyoshi; UEMURA, Takashi; KOBATAKE, Yui; SHIMAMURA, Shunsuke; KITAMURA, Naoki; MAEDA, Sadatoshi; UZUKA, Yuji; SHAW, Gerry; YASUDA, Jun

    2014-01-01

    The aim of this study was to evaluate the prognostic value of concurrent measurement of serum phosphorylated neurofilament heavy subunit (pNF-H) concentration and intramedullary T2W hyperintensity in paraplegic to paraplegic dogs. Our hypothesis was that concurrent measurement of these would provide a more accurate prediction of functional outcome in dogs with thoracolumbar intervertebral disc herniation (IVDH). A prospective case-control clinical study was designed using 94 dogs with acute onset of thoracolumbar IVDH. The association of serum pNF-H concentration, T2W hyperintensity on sagittal MRI (T2H/L2), deep pain perception and surgical outcome were evaluated with logistic regression analysis after three months for all 94 surgically treated dogs. Sensitivity to predict non-ambulatory outcome was compared among pNF-H and T2H/L2 and combination of both. Logistic regression analysis indicated that serum pNF-H concentration and T2H/L2 were significantly correlated with surgical outcome (P<0.05); however, deep pain perception was not (P=0.41). The results of logistic regression analysis indicated that the odds ratios of unsuccessful long-term outcome were 2.6 for serum pNF-H concentration, 1.9 for T2H/L2 and 2.3 for deep pain sensation. The sensitivity and specificity to predict non-ambulatory outcome for using serum parameter pNF-H>2.6 ng/ml, using T2H/L2 value of>0.84 and using both serum pNF-H and T2H/L2, were 95% and 75.7%, 65% and 86.5%, and 90.0% and 97.5%, respectively. Therefore, combined measurements of serum pNF-H and T2H/L2 might be useful for predicting long-term outcome in dogs with thoracolumbar IVDH. PMID:25650056

  12. The long-term course of patients undergoing alternative and integrative therapy for lumbar disc herniation: 3-year results of a prospective observational study

    PubMed Central

    Shin, Joon-Shik; Lee, Jinho; Kim, Me-riong; Shin, Byung-Cheul; Lee, Myeong Soo; Ha, In-Hyuk

    2014-01-01

    Objectives This study aimed to assess the efficacy and safety of an integrative complementary and alternative medicine (CAM) approach in the management of lumbar herniated disc (LHD) with sciatic pain and investigate pain relapse, use of medical care and surgery rates in patients who actively chose non-surgical CAM treatment for LHD. Study design/Setting This prospective observational study was undertaken at a Korean medicine hospital outpatient setting in Korea. Participants A total of 128 consecutive patients with LHD with a numeric rating scale for leg pain of ?5 completed 6?months of CAM treatment after recruitment from November 2006, and 73/128 participants (57%) attended follow-up 3?years later. Interventions 6?months of CAM treatment (herbal medicine, acupuncture, bee venom pharmacopuncture, and Chuna manipulation). Primary outcome measures Visual analogue scale (VAS) for low back and leg pain, Oswestry Disability Index (ODI), and Short Form (SF)-36 Health Survey. Secondary outcome measures Neurological impairment (muscular weakness, sensory loss, Straight Leg Raise test), MRIs, recurrence of low back pain and/or radiating pain, and use of medical care. Results 92 patients could be assessed for surgical state, of whom 4 replied that they had received surgery. 73 patients attended the 3-year follow-up. The baseline VAS of back pain (4.37±2.70) decreased after treatment (0.90±1.01; p<0.001) and was maintained at 3?years (1.12±1.64; p=0.19). The baseline VAS of leg pain (7.57±1.40) also decreased on treatment (0.82±1.18; p<0.001) and was sustained at 3?years (0.99±1.58; p=0.34). ODI scores declined from 40.74±16.15 to 9.84±9.67 (p<0.001), then decreased further to 6.30±7.19 (p<0.01). SF-36 scores increased from 34.96±13.30 to 69.20±14.96 (p<0.001), reaching 76.19±14.45 (p<0.001) at 3?years. 37 patients reported recurrence of pain and most chose CAM treatment for management of relapse symptoms. Conclusions Although the absence of a control group prevents validation of effectiveness, many patients showed favourable long-term outcomes. Trial registration number ClinicalTrials.gov Identifier: NCT01989403.

  13. Childhood intervertebral disc calcification

    Microsoft Academic Search

    B. Theo Mellion; John P. Laurent; William C. Watters

    1993-01-01

    Two cases of intervertebral disc calcification in children are reported. A 13-year-old boy presented with right subscapular pain radiating into the axilla with radiographic demonstration of multiple calcified intervertebral discs and a herniated fragment of calcified nucleus pulposus at T2–3. His condition improved with conservative therapy, and follow-up radiographic evaluation revealed resolution of the herniated calcified disc material. A second

  14. Lumbar disc herniation in teenagers

    Microsoft Academic Search

    Luigi Ferrante; Luciano Mastronardi; Pierpaolo Lunardi; Fabrizio Puzzilli; Aldo Fortuna

    1992-01-01

    48 patients ont été opérés de hernie lombaire discale dans les deux premières décades de vie (âge 13–20), dans notre Division de Neurochirurgie. On a comparé les différences cliniques et chirurgicales entre les adultes et les enfants, nous avons étudié plus de 900 cas juvéniles en comparaison avec plus de 11000 cas adultes décrits dans la littérature. La douleur lombaire

  15. Lipoxin A4 attenuates radicular pain possibly by inhibiting spinal ERK, JNK and NF-?B/p65 and cytokine signals, but not p38, in a rat model of non-compressive lumbar disc herniation.

    PubMed

    Miao, G-S; Liu, Z-H; Wei, S-X; Luo, J-G; Fu, Z-J; Sun, T

    2015-08-01

    Inflammatory response induced by protrused nucleus pulposus (NP) has been shown to play a crucial role in the process of radicular pain. Lipoxins represent a unique class of lipid mediators that have anti-inflammatory and pro-resolving action. The present study was undertaken to investigate if intrathecal lipoxin A4 (LXA4) could alleviate mechanical allodynia in the rat models of application of NP to the L5 dorsal root ganglion (DRG). Non-compressive models of application of NP to L5 DRG were established and intrathecal catheterization for drug administration was performed in rats. Daily intrathecal injection of vehicle or LXA4 (10ng or 100ng) was performed for three successive days post-operation. Mechanical thresholds were tested and the ipsilateral lumbar (L4-L6) segment of spinal dorsal horns were removed for the determination of tumor necrosis factor-? (TNF-?), IL-1?, transforming growth factor-?1 (TGF-?1) and IL-10 expression and NF-?B/p65, extracellular signal-regulated kinase (ERK), C-Jun N-terminal kinase (JNK) and P38 expression. Application of NP to DRG in rats induced mechanical allodynia, increased the expression of pro-inflammatory factors (TNF-? and IL-1?), NF-?B/p65, the phosphorylated-ERK (p-ERK), -JNK (p-JNK) and -P38 (p-p38) and decreased the expression of anti-inflammatory cytokines (TGF-?1 and IL-10) in the ipsilateral lumbar (L4-L6) segment of spinal dorsal horns. Intrathecal injection of LXA4 alleviated the development of neuropathic pain, inhibited the upregulation of pro-inflammatory cytokines (TNF-? and IL-1?), upregulated the expression of anti-inflammatory cytokines (TGF-?1 and IL-10) and attenuated the activation of NF-?B/p65, p-ERK, p-JNK, but not p-p38, in a dose-dependent manner. In this study, we have demonstrated that LXA4 potently alleviate radicular pain in a rat model of non-compressive lumbar disc herniation. The anti-inflammatory and pro-resolution properties of LXA4 have shown a great promise for the management of radicular pain caused by intervertebral disc herniation. PMID:25943485

  16. Clinical Results of a Single Central Interbody Fusion Cage and Transpedicle Screws Fixation for Recurrent Herniated Lumbar Disc and Low-Grade Spondylolisthesis

    Microsoft Academic Search

    Kuo-Feng Huang; Tzu-Yung Chen

    Background: The posterior lumbar interbody fusion (PLIF) procedure allows restoration of the weight-bearing capacity to a more physiological ventral position and maintenance of disc space height. However, the procedure can be technically difficult and may cause complications. It has always been performed bilater- ally with paired cages; a single central cage has not been commonly used. Methods: Twenty-eight patients who

  17. Prolonged conservative care versus early surgery in patients with sciatica caused by lumbar disc herniation: two year results of a randomised controlled trial

    Microsoft Academic Search

    Wilco C Peul; Wilbert B van den Hout; Ronald Brand; Ralph T W M Thomeer; Bart W Koes

    2008-01-01

    Objectives To evaluate the effects of early lumbar disc surgery compared with prolonged conservative care for patients with sciatica over two years of follow-up.Design Randomised controlled trial.Setting Nine Dutch hospitals.Participants 283 patients with 6-12 weeks of sciatica.Interventions Early surgery or an intended six months of continued conservative treatment, with delayed surgery if needed.Main outcome measures Scores from Roland disability questionnaire

  18. Quantitative Discomanometry: Correlation of Intradiscal Pressure Values to Pain Reduction in Patients With Intervertebral Disc Herniation Treated With Percutaneous, Minimally Invasive, Image-Guided Techniques

    SciTech Connect

    Filippiadis, Dimitrios K., E-mail: dfilippiadis@yahoo.gr; Mazioti, A., E-mail: argyromazioti@yahoo.gr; Papakonstantinou, O., E-mail: sogofianol@gmail.com; Brountzos, E., E-mail: ebrountz@med.uoa.gr [University General Hospital 'Attikon', Second Radiology Department (Greece); Gouliamos, A., E-mail: agouliam@med.uoa.gr [University General Hospital 'Areteion', First Radiology Department (Greece); Kelekis, N., E-mail: kelnik@med.uoa.gr; Kelekis, A., E-mail: akelekis@med.uoa.gr [University General Hospital 'Attikon', Second Radiology Department (Greece)

    2012-10-15

    Purpose: To illustrate quantitative discomanometry's (QD) diagnostic efficacy and predictive value in discogenic-pain evaluation in a prospective study correlating intradiscal pressure values with pain reduction after percutaneous image-guided technique (i.e., percutaneous decompression, PD). Materials and Methods: During the last 3 years, 36 patients [21 male and 15 female (mean age 36 {+-} 5.8 years)] with intervertebral disc hernia underwent QD before PD. Under absolute sterilization and fluoroscopy, a mixture of contrast medium and normal saline (3:1 ratio) was injected. A discmonitor performed a constant rate injection and recorded pressure and volume values, thus producing the relative pressure-volume curve. PD was then performed. Pain reduction and improved mobility were recorded at 3, 12, and 24 months after PD using clinical evaluation and a numeric visual scale (NVS; 0 to 10 units). Results: Mean pain values of 7.5 {+-} 1.9 (range 4 to 8) NVS units were recorded before PD; these decreased to 2.9 {+-} 2.44 at 3 months, 1.0 {+-} 1.9 at 12 months, and 1.0 {+-} 1.9 NVS units at 24 months after PD. Recorded correlations (pressure, volume, significant pain-reduction values) with bilateral statistical significance included a maximum injected volume of 2.4 ml (p = 0.045), P{sub o} < 14 psi [initial pressure required to inject 0.1 ml of the mixture inside the disc (p = 0.05)], P{sub max} {<=} 65 psi [greatest pressure value on the curve (p = 0.018)], and P{sub max} - P{sub o} {<=} 47 psi (p = 0.038). Patients meeting these pressure or volume cut-off points, either independently or as a total, had significant pain reduction (>4 NVS units) after PD. No complications were noted. Conclusions: QD is an efficient technique that may have predictive value for discogenic pain evaluation. It might serve as a useful tool for patient selection for intervertebral disc therapies.

  19. [Effects of 3-hydroxypyridine and succinic acid derivatives on the dynamics of dorsalgia and affective disorders after surgical treatment of disc herniation].

    PubMed

    Volchegorski?, I A; Mester, K M

    2010-01-01

    A prospective, placebo-controlled randomized study of the effects of 3-hydropxypyridine and succinic acid derivatives (emoxipine, reamberin and mexi the early dynamics of dorsalgia and the corresponding affective disorders has been performed in 136 patients after surgical treatment of lumbal disc hen It is established that a two-week administration of all preparations reduced the manifestations of depression during 3.5 months after spinal surgery. The course of emoxipine (150 mg, i.v., daily) produced an antidepressant effect without any changes in the dynamics of dorsalgia, psychological dysada (PD), and quality of life (QL). The 14-day administration of reamberin (400 ml, i.v., daily) significantly reduced in the manifestations of depression and pathic pain, without any effect upon nociceptive pain, PD, and QL dynamics. The two-week course of mexidol (300 mg, i.v., daily) led to the most pron antidepressant effect, which was accompanied by the attenuation of both nociceptive and neuropathic pain, a decrease in PD, and appreciable increase in ter the surgical treatment. PMID:20184287

  20. The presence and absence of lymphatic vessels in the adult human intervertebral disc: relation to disc pathology

    Microsoft Academic Search

    Karolina Kliskey; Kelly Williams; J. Yu; David Jackson; Jill Urban; Nick Athanasou

    2009-01-01

    Objective  Although the normal adult human intervertebral disc is considered to be avascular, vascularised cellular fibrous tissue can\\u000a be found in pathological conditions involving the disc such as disc herniation. Whether lymphatics vessels form a component\\u000a of this reparative tissue is not known as the presence or absence of lymphatics in herniated and normal disc tissue is not\\u000a known. We examined

  1. Cervical arthroplasty using ProDisc-C Case Report

    PubMed Central

    Nica, DA; Copaciu, R

    2013-01-01

    Cervical disc replacement is an emerging motion-preserving technology in the surgical treatment of the cervical degenerative disc disorders used as an alternative to the classic interbody fusion. We present a case report of a patient diagnosed with C6-7 right disc herniation who underwent anterior discectomy and received a total disc replacement using ProDisc C artificial disc prosthesis. PMID:23599830

  2. Cervical arthroplasty using ProDisc-C case report.

    PubMed

    Nica, D A; Copaciu, R

    2013-03-15

    Cervical disc replacement is an emerging motion-preserving technology in the surgical treatment of the cervical degenerative disc disorders used as an alternative to the classic interbody fusion. We present a case report of a patient diagnosed with C6-7 right disc herniation who underwent anterior discectomy and received a total disc replacement using ProDisc C artificial disc prosthesis. PMID:23599830

  3. Can E-selectin be a reliable marker of inflammation in lumbar disc disease?

    Microsoft Academic Search

    Orhan Sen; M. Volkan Aydin; Celal Bagdatoglu; M. Eda Ertorer; Filiz Aka Bolat; Ozlem Yalcin; Hakan Caner; Nur Altinors

    2005-01-01

    The cause of sciatica and low back pain associating with lumbar disc herniation has not been clearly identified until now. Inflammation has been shown to occur via immunohistochemical and biochemical methods in herniated disc tissues. The important prognostic role of E-selectin has recently been substantiated by other studies in early rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA). The important

  4. Failure of the Intervertebral Disc

    Microsoft Academic Search

    Famke Kraaijeveld; Jacques M. Huyghe; Joris J. C. Remmers; Rene de Borst; Frank P. T. Baaijens

    2008-01-01

    In ionized porous media, such as shales, clays and biological tissues, localization or even crack forma- tion during swelling or shrinking can take place. This can lead to for example earthquakes, borehole instability and intervertebral disc (IVD) herniation. The goal is to study the effect of swelling on the failure mechanism. Currently, there is no numerical framework which includes osmotic

  5. Experimental model of multidirectional disc hernia in rats

    Microsoft Academic Search

    A. Latorre; J. Albareda; T. Castiella; J. M. Lasierra; F. Seral

    1998-01-01

    Summary. We have carried out an experimental investigation of lesions of the intervertebral disc produced by flexion, lateral bending\\u000a and rotational forces in an attempt to produce disc herniations. Adult Wistar rats were divided into 4 groups: control and\\u000a posterior, lateral and rotational herniation. There were 10 rats in each group. The tail between the 5th and 8th vertebral\\u000a segments

  6. Paraduodenal herniation: An internal herniation in a virgin abdomen

    PubMed Central

    Kabbani, Dana; Salem, Ayman; Holloway, Daniel K.

    2014-01-01

    INTRODUCTION A paraduodenal hernia is an uncommon hernia that results from an abnormal rotation of the midgut. Commonly, these hernias are congenital in nature, and are reported to cause 1.5–5.8% of intestinal obstructions. These hernias occur when a part of the jejunum herniates through the posterior portion of the ligament of Treitz. Diagnosing these hernias preoperatively has been shown to be difficult, despite the studies that are available. Early diagnosis is imperative to the patient in order to avoid strangulation of the bowel, which is associated with a high mortality. PRESENTATION OF CASE In this case, we present a case of a left-sided paraduodenal hernia in a virgin abdomen in a 38-year-old African American male with a herniation of a loop of jejunum through a defect of the posterior portion of the ligament of Treitz. The patient also had a volvulized segment of the proximal jejunum, and part of this bowel was found to be ischemic. DISCUSSION Acute intestinal obstruction caused by a left paraduodenal hernia is a rare cause of intestinal obstruction. A literary search of PubMed between 1980 and 2012 indicated only 44 cases of intestinal obstruction secondary to a left paraduodenal hernia. CONCLUSION The patient underwent exploratory laparotomy, and the herniated bowel was found to be ischemic. The hernia was reduced, and the ischemic bowel resected. The defect was closed, and the patient had a non-complicated recovery. PMID:25437660

  7. [Traumatic recurrence of idiopathic spinal cord herniation].

    PubMed

    Lorente-Muñoz, Asís; Cortés-Franco, Severiano; Moles-Herbera, Jesús; Casado-Pellejero, Juan; Rivero-Celada, David; Alberdi-Viñas, Juan

    2013-01-01

    Idiopathic spinal cord herniation is a rare cause of thoracic myelopathy and its recurrence is even more infrequent. Cord herniation is through an anterior dural defect in thoracic spine with unknown causes. Symptomatic cases must be surgically treated to reduce the hernia and seal the defect to prevent recurrences. We report a patient presenting a Brown-Séquard syndrome secondary to a D5 spinal cord herniation treated successfully and its posterior traumatic recurrence. PMID:23453309

  8. A collagen-GAG matrix for the growth of intervertebral disc tissue

    E-print Network

    Hastreiter, Dawn (Dawn Marie), 1973-

    2002-01-01

    Intervertebral disc (IVD) degeneration and herniation is a significant problem, more so in the aviation field. The IVD also changes during spaceflight. Current treatments for IVD problems can have unfavorable long-term ...

  9. Herniation of the mylohyoid muscle.

    PubMed

    Windisch, Gunther; Weiglein, Andreas H; Kiesler, Karl

    2004-07-01

    During ultrasound examinations in patients with dysphagia, deficiencies in the mylohyoid muscle with herniation of the sublingual gland were found, which may be mistaken as soft tissue tumors. Between the years 2001 and 2003, 205 half-heads used in dissection courses were examined to determine the location and contents of these gaps. In 25 of these cadaveric specimens, the hiatus (of variable size) appeared as small fissures between the divided fibers of the mylohyoid. In 18 cases (72%), the sublingual gland slipped through these deficiencies and occurred in the front part of the submandibular triangle. From the inferior surface of the muscle, the submental artery also coursed through the separated muscle fibers. The herniations of 7 specimens (28%) were found without any contents, neither with gland perforation nor with a submental artery. The following study points out the spatial relation of the salivary glands to the floor of the mouth and the clinical significance, and some factors referred to the development of herniations are discussed. PMID:15213531

  10. MRI Evaluation of Lumbar Disc Degenerative Disease

    PubMed Central

    Patel, Rupal; Mehta, Chetan; Patel, Narrotam

    2015-01-01

    Introduction: Lower back pain secondary to degenerative disc disease is a condition that affects young to middle-aged persons with peak incidence at approximately 40 y. MRI is the standard imaging modality for detecting disc pathology due to its advantage of lack of radiation, multiplanar imaging capability, excellent spinal soft-tissue contrast and precise localization of intervertebral discs changes. Aims and Objective: To evaluate the characterization, extent, and changes associated with the degenerative lumbar disc disease by Magnetic Resonance Imaging. Study Design: Cross-sectional and observational study. Materials and Methods: A total 109 patients of the lumbar disc degeneration with age group between 17 to 80 y were diagnosed & studied on 1.5 Tesla Magnetic Resonance Imaging machine. MRI findings like lumbar lordosis, Schmorl’s nodes, decreased disc height, disc annular tear, disc herniation, disc bulge, disc protrusion and disc extrusion were observed. Narrowing of the spinal canal, lateral recess and neural foramen with compression of nerve roots observed. Ligamentum flavum thickening and facetal arthropathy was observed. Result: Males were more commonly affected in Degenerative Spinal Disease & most of the patients show loss of lumbar lordosis. Decreased disc height was common at L5-S1 level. More than one disc involvement was seen per person. L4 – L5 disc was the most commonly involved. Annular disc tear, disc herniation, disc extrusion, narrowing of spinal canal, narrowing of lateral recess, compression of neural foramen, ligamentum flavum thickening and facetal arthropathy was common at the L4 –L5 disc level. Disc buldge was common at L3 – L4 & L4 – L5 disc level. Posterior osteophytes are common at L3 - L4 & L5 –S1 disc level. L1- L2 disc involvement and spondylolisthesis are less common. Conclusion: Lumbar disc degeneration is the most common cause of low back pain. Plain radiograph can be helpful in visualizing gross anatomic changes in the intervertebral disc. But, MRI is the standard imaging modality for detecting disc pathology due to its advantage of lack of radiation, multiplanar imaging capability, excellent spinal soft-tissue contrast and precise localization of intervertebral discs changes. PMID:26023617

  11. Higher risk of dural tears and recurrent herniation with lumbar micro-endoscopic discectomy

    Microsoft Academic Search

    Marco Teli; Alessio Lovi; Marco Brayda-Bruno; Antonino Zagra; Andrea Corriero; Fabrizio Giudici; Leone Minoia

    2010-01-01

    Existing studies on micro-endoscopic lumbar discectomy report similar outcomes to those of open and microdiscectomy and conflicting\\u000a results on complications. We designed a randomised controlled trial to investigate the hypothesis of different outcomes and\\u000a complications obtainable with the three techniques. 240 patients aged 18–65 years affected by posterior lumbar disc herniation\\u000a and symptoms lasting over 6 weeks of conservative management were randomised

  12. A new pathological classification of lumbar disc protrusion and its clinical significance.

    PubMed

    Ma, Xin-long

    2015-02-01

    Lumbar disc protrusion is common. Its clinical manifestations and treatments are closely related to the pathological changes; however, the pathological classification of lumbar disc protrusion is controversial. This article introduces a new pathological classification comprising four types of lumbar disc protrusion according to intraoperative findings. The damage-herniation type is probably caused by injury and is characterized by soft herniation, the capsule can easily be cut and the broken disc tissue blocks overflow or is easily removed. The broken disc substances should be completely removed; satisfactory results can be achieved by minimally invasive endoscopic surgery. The degeneration-protrusion type is characterized by hard and tough protrusions and the pathological process by degeneration and proliferative reaction. The nerve should be decompressed and relaxed with minimally invasive removal of the posterior wall; the bulged or protruded disc often need not be excised. The posterior vertebral osteochondrosis with disc protrusion type is characterized by deformity of the posterior vertebral body, osteochondral nodules and intervertebral disc protrusion. The herniated and fragmented disc tissue should be removed with partially protruding osteochondral nodules. Intervertebral disc cyst is of uncertain pathogenesis and is characterized by a cyst that communicates with the disc. Resection of the cyst under microscopic or endoscopic control can achieve good results; and whether the affected disc needs to be simultaneously resected is controversial. The new pathological classification proposed here is will aid better understanding of pathological changes and pathogenesis of lumbar disc protrusion and provides a reference for diagnosis and treatment. PMID:25708029

  13. Unusual case of camptocormia triggered by lumbar-disc herniation

    Microsoft Academic Search

    Iltekin Duman; Korhan Baklac?; Arif Kenan Tan; Tunc Alp Kalyon

    2008-01-01

    A 21-year-old male patient with low back pain and marked forward bending was presented. The exaggerated lumbar flexion was\\u000a preventing him to stand in erect posture but disappeared while lying. The symptoms had begun after he had lifted a heavy object.\\u000a Straight-leg-raising test could not be performed properly because of the exaggerated pain. The light-touch sense was decreased\\u000a on L5

  14. Cerebellopontine angle empyema after lumbar disc herniation surgery

    PubMed Central

    Nascimento, Clarissa Gambara; Brock, Roger Schmidt; Morais, Barbara Albuquerque; Tavares, Wagner Malagó; Teixeira, Manoel Jacobsen; Paiva, Wellingson Silva

    2015-01-01

    Background: Lumbar discectomy is still one of the most common spinal surgeries performed today. Nevertheless, there are few publications considering severe complications. Case Description: We report a case with severe complication, without any previous report, a brain empyema after cerebrospinal fluid leak with good outcome afterword. A 45 years old man, returned six days after surgery, presenting cerebrospinal fluid leak, which after clinical and laboratory deterioration was reoperated. In the 14th postoperative facing worsening level of consciousness was diagnosed empyema in cerebellopontine angle and hydrocephalus underwent emergency surgery. Evolved with hemiplegia in the first postoperative attributed to vasculitis, completely recovered after 5 days. Conclusions: Although infrequent, lumbar discectomy is subject to severe complications, which as the case presented, can be dramatic. In surgeries must be careful to avoid cerebrospinal fluid leak e infectious complications.

  15. Thoracoabdominal herniation--but not as you know it.

    PubMed

    Wigley, J; Noble, F; King, A

    2014-07-01

    Thoracoabdominal hernias are uncommon following blunt trauma. If diaphragmatic rupture does occur, the abdominal viscera can herniate into the thorax through the diaphragm. We report a rare case of thoracoabdominal herniation in which the bowel herniated through the lateral abdominal wall, migrating cranially and entering the thorax through an intercostal defect. This case highlights the need for early and definitive surgical repair. PMID:24992399

  16. Case report: The operation for the lumbar disk herniation just after cesarean delivery in the third trimester of pregnancy

    PubMed Central

    Ochi, Hironori; Ohno, Ryuichi; Kubota, Mitsuaki; Hanyu, Ryo; Sakai, Kensuke; Sugawara, Yu; Mukasa, Fumihiro; Kaneko, Kazuo

    2014-01-01

    INTRODUCTION Low back pain is common during pregnancy. However, the incidence of symptomatic lumbar disc herniation during pregnancy is very rare. We report a case of lumbar disc herniation underwent discectomy just after cesarean delivery in the third trimester of pregnancy. PRESENTATION OF CASE A 33-year-old woman presented at 32 weeks gestation. She had a low back pain and the left-sided leg pain below the knee. At 34 weeks gestation, she had severe weakness of the left extension halluces longus, left ankle dorsiflexion. MRI showed a large disc herniation at L4/5 expanded to the spinal canal more. The cesarean delivery was performed in the supine position. The patient was then turned to a prone position, and a left L4/5 discectomy was performed. But the day after surgery, she had a severe low back pain and the right leg pain below the knee. MRI showed a disc herniation at L4/5 on the right side of the spinal canal. At 6 days after the first surgery, a right L4/5 discectomy was performed. In the immediate postoperative period, the patient experienced complete relief of the right leg pain. DISCUSSION It is necessary to cooperate with a pediatrician, an obstetrician, and an anethesiologists. For obtaining the best outcome on mother and child, it is important to discuss in advance to be able to respond quickly for changeable situation. CONCLUSION It is necessary to conduct the operation under pregnancy in consideration of the great influence on mother and child. PMID:25437670

  17. 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

  18. Percutaneous diode laser disc nucleoplasty

    NASA Astrophysics Data System (ADS)

    Menchetti, P. P.; Longo, Leonardo

    2004-09-01

    The treatment of herniated disc disease (HNP) over the years involved different miniinvasive surgical options. The classical microsurgical approach has been substituted over the years both by endoscopic approach in which is possible to practice via endoscopy a laser thermo-discoplasty, both by percutaneous laser disc nucleoplasty. In the last ten years, the percutaneous laser disc nucleoplasty have been done worldwide in more than 40000 cases of HNP. Because water is the major component of the intervertebral disc, and in HNP pain is caused by the disc protrusion pressing against the nerve root, a 980 nm Diode laser introduced via a 22G needle under X-ray guidance and local anesthesia, vaporizes a small amount of nucleous polposus with a disc shrinkage and a relief of pressure on nerve root. Most patients get off the table pain free and are back to work in 5 to 7 days. Material and method: to date, 130 patients (155 cases) suffering for relevant symptoms therapy-resistant 6 months on average before consulting our department, have been treated. Eightyfour (72%) males and 46 (28%) females had a percutaneous laser disc nucleoplasty. The average age of patients operated was 48 years (22 - 69). The level of disc removal was L3/L4 in 12 cases, L4/L5 in 87 cases and L5/S1 in 56 cases. Two different levels were treated at the same time in 25 patients. Results: the success rate at a minimum follow-up of 6 months was 88% with a complication rate of 0.5%.

  19. Clarifying the nomenclature of intervertebral disc degeneration and displacement: from bench to bedside.

    PubMed

    Wang, Hai-Qiang; Samartzis, Dino

    2014-01-01

    As a significant determinant of low back pain, intervertebral disc degeneration (IDD) has attracted more and more attention of both investigators and physicians. Disc herniation, termed as intervertebral disc displacement, is amongst the most prevalent spinal diseases closely linked with IDD. Due to the same origins and similar pathophysiology, the ambiguity regarding the similarity and difference of IDD and intervertebral disc displacement thus remains. The aim of this study was to clarify the nomenclature of IDD and disc herniation in terms of molecular etiology, pathophysiology, nature history and clinical outcomes. Collectively, IDD is a type of multifaceted, progressive spinal disease with or without clinical symptoms as back pain, characterized by extracellular matrix and the integrity of NP and AF lost, fissures formation. Disc herniation (termed as intervertebral disc displacement) is a type of spinal disease based on IDD or not, with local pain and/or sciatica due to mechanical compression and autoimmune cascades upon the corresponding nerve roots. Clarifying the nomenclature of intervertebral disc degeneration and displacement has important implications both for investigators and for physicians. PMID:24817926

  20. Use of lumbar extension, slump test, physical and neurological examination in the evaluation of patients with suspected herniated nucleus pulposus. A prospective clinical study.

    PubMed

    Stankovic, R; Johnell, O; Maly, P; Willner, S

    1999-02-01

    This prospective and consecutive study was designed to evaluate the validity of different clinical tests, e.g. lumbar extension in lying and slump test for patients with suspected herniated nucleus pulposus, in comparison with findings on computed tomography (CT) and/or magnetic resonance imaging (MRI) scan. There were 105 patients who were seen and examined by the senior author (for the sake of the study) at the Orthopaedic Physiotherapy Department, on an average of 5.5 days (range 0-21 days) before CT and/or MRI examination were carried out. There were 36 women and 69 men with an average age of 42.7 +/- 9.8 (range 19-64) years. According to the radiological findings on CT and/or MRI, the patients were divided into three groups: 52 patients with disc hernia, 41 patients with bulging discs and 12 patients without positive findings. The mean values with standard deviations of 25 variables of three diagnostic groups were studied. Multiple comparison adjustment according to Bonferroni showed significant differences for three variables that were of diagnostic value (lumbar range of motion for forward flexion, left side-bending in standing, and pain distribution during extension in standing). The agreement between clinical and radiological findings for type and level of diagnosis of disc herniation was accurate in 72 patients (69%). The diagnostic sensitivity for disc herniation was 82.6% and the specificity 54.7%. PMID:10463018

  1. Lumbar Disk Herniation Surgery: Outcome and Predictors

    PubMed Central

    Sedighi, Mahsa; Haghnegahdar, Ali

    2014-01-01

    Study Design?A retrospective cohort study. Objectives?To determine the outcome and any differences in the clinical results of three different surgical methods for lumbar disk herniation and to assess the effect of factors that could predict the outcome of surgery. Methods?We evaluated 148 patients who had operations for lumbar disk herniation from March 2006 to March 2011 using three different surgical techniques (laminectomy, microscopically assisted percutaneous nucleotomy, and spinous process osteotomy) by using Japanese Orthopaedic Association (JOA) Back Pain Evaluation Questionnaire, Resumption of Activities of Daily Living scale and changes of visual analog scale (VAS) for low back pain and radicular pain. Our study questionnaire addressed patient subjective satisfaction with the operation, residual complaints, and job resumption. Data were analyzed with SPSS version 16.0 (SPSS, Inc., Chicago, Illinois, United States). Statistical significance was set at 0.05. For statistical analysis, chi-square test, Mann-Whitney U test, Kruskal-Wallis test, and repeated measure analysis were performed. For determining the confounding factors, univariate analysis by chi-square test was used and followed by logistic regression analysis. Results?Ninety-four percent of our patients were satisfied with the results of their surgeries. VAS documented an overall 93.3% success rate for reduction of radicular pain. Laminectomy resulted in better outcome in terms of JOA Back Pain Evaluation Questionnaire. The outcome of surgery did not significantly differ by age, sex, level of education, preoperative VAS for back, preoperative VAS for radicular pain, return to previous job, or level of herniation. Conclusion?Surgery for lumbar disk herniation is effective in reducing radicular pain (93.4%). All three surgical approaches resulted in significant decrease in preoperative radicular pain and low back pain, but intergroup variation in the outcome was not achieved. As indicated by JOA Back Pain Evaluation Questionnaire–Low Back Pain (JOABPQ-LBP) and lumbar function functional scores, laminectomy achieved significantly better outcome compared with other methods. It is worth mentioning that relief of radicular pain was associated with subjective satisfaction with the surgery among our study population. Predictive factors for ineffective surgical treatment for lumbar disk herniation were female sex and negative preoperative straight leg raising. Age, level of education, and preoperative VAS for low back pain were other factors that showed prediction power. PMID:25396104

  2. Deuk Laser Disc Repair® is a safe and effective treatment for symptomatic cervical disc disease

    PubMed Central

    Deukmedjian, Ara J.; Jason Cutright, S. T.; Augusto Cianciabella, PA-C; Deukmedjian, Arias

    2013-01-01

    Background: Deuk Laser Disc Repair® is a new full-endoscopic surgical procedure to repair symptomatic cervical disc disease. Methods: A prospective cohort of 66 consecutive patients underwent cervical Deuk Laser Disc Repair® for one (n = 21) or two adjacent (n = 45) symptomatic levels of cervical disc disease and were evaluated postoperatively for resolution of headache, neck pain, arm pain, and radicular symptoms. All patients were candidates for anterior cervical discectomy and fusion (ACDF) or arthroplasty. The Mann–Whitney Wilcoxon test was used to calculate P values. Results: All patients (n = 66) had significant improvement in preoperative symptoms with an average symptom resolution of 94.6%. Fifty percent (n = 33) had 100% resolution of all preoperative cervicogenic symptoms. Only 4.5% (n = 3) had less than 80% resolution of preoperative symptoms. Visual analog scale (VAS) significantly improved from 8.7 preoperatively to 0.5 postoperatively (P < 0.001) for the cohort. Average operative and recovery times were 57 and 52 minutes, respectively. There were no perioperative complications. Recurrent disc herniation occurred in one patient (1.5%). Average postoperative follow-up was 94 days and no significant intergroup difference in outcomes was observed (P = 0.111) in patients with <90 days (n = 52) or >90 days (n = 14, mean 319 days) follow-up. No significant difference in outcomes was observed (P = 0.774) for patients undergoing one or two level Deuk Laser Disc Repair®. Patients diagnosed with postoperative cervical facet syndrome did significantly worse (P < 0.001). Conclusion: Deuk Laser Disc Repair® is a safe and effective alternative to ACDF or arthroplasty for the treatment of one or two adjacent symptomatic cervical disc herniations with an overall success rate of 94.6%. PMID:23776754

  3. Annulo-nucleoplasty using Disc-FX in the management of lumbar disc pathology: Early results

    PubMed Central

    Kumar, Aravind; Siddharth M, Shah; Sambhav P, Shah; Tan, Justin

    2014-01-01

    Background Back pain due to Lumbar Disc Disease is a major clinical problem. The treatment options range from physiotherapy to fusion surgery. A number of minimally invasive procedures have also been developed in the recent past for its management. Disc-FX is a new minimally invasive technique that combines percutaneous discectomy, nuclear ablation and annular modification. Literature on its role in the management of lumbar disc pathology is scarce. Methods We included 24 consecutive patients who underwent the Disc-FX for back pain due to lumbar disc pathology non-responsive to non-operative treatment for a period of at least 6 months. Based on Magnetic Resonance Imaging (MRI) these patients fell into 2 groups – those with degenerative disc disease (DDD) (n = 12) and those with a contained lumbar disc herniation (CLDH)(n = 12). They were evaluated using the Visual analogue scale (VAS), Oswestry Disability Index (ODI) and Short Form-36 (SF-36) scores preoperatively and postoperatively. Results The mean age was 37.9 years (21-53 years). There were 17 males and 7 females. One patient in each subgroup was excluded from the final evaluation. Significant improvement was seen in all outcome measures. The overall rate of reintervention for persistent symptoms was 18.18% (4/22); in the CLDH subgroup, it was 36.36% (4/11). Conclusions and level of evidence Early results after the Disc-FX procedure suggest that it s a reasonable treatment option for patients with back pain due to lumbar disc disease, especially for those with DDD who fail conservative treatment. It could be an alternative to procedures like fusion or disc replacement. This study presents Level IV evidence. Clinical relevance We feel that our study establishes Disc-FX as a modality of treating symptomatic lumbar disc disease due to DDD. However, longer term prospective studies are needed to prove this and to evaluate its role in the treatment of patients with CLDH. PMID:25694914

  4. Lumbar spinal surgery for sciatica due to intervertebral disc disease in the elderly

    Microsoft Academic Search

    Alpaslan Kulali; Klaus von Wild

    1996-01-01

    This report reviews 36 patients aged 71 to 93 years who had lumbar spinal surgey for sciatica pain some with motor and or sensory disturbances and with no motor and sensory disturbances. Even though we found soft disc herniations, these patients should have a thorough circumferential decompression because of bony osteophytes and facet hypertrophy. Special attention is drawn to the

  5. The influence of slouching and lumbar support on iliolumbar ligaments, intervertebral discs and sacroiliac joints

    Microsoft Academic Search

    Chris J. Snijders; Paul F. G. Hermans; Ruud Niesing; Cornelis W. Spoor; Rob Stoeckart

    2004-01-01

    Objective. To investigate lumbopelvic kinematics when moving into a slouch.Design. A biomechanical model was developed. Load tests in vitro verified the model.Background. The precise mechanism causing disc herniation and back sprain is still debated. Most biomechanical studies have focused on lifting in a stooped posture. Previous studies address instability situations due to Euler buckling of the spine under axial load.

  6. Higher risk of dural tears and recurrent herniation with lumbar micro-endoscopic discectomy

    PubMed Central

    Lovi, Alessio; Brayda-Bruno, Marco; Zagra, Antonino; Corriero, Andrea; Giudici, Fabrizio; Minoia, Leone

    2010-01-01

    Existing studies on micro-endoscopic lumbar discectomy report similar outcomes to those of open and microdiscectomy and conflicting results on complications. We designed a randomised controlled trial to investigate the hypothesis of different outcomes and complications obtainable with the three techniques. 240 patients aged 18–65 years affected by posterior lumbar disc herniation and symptoms lasting over 6 weeks of conservative management were randomised to micro-endoscopic (group 1), micro (group 2) or open (group 3) discectomy. Exclusion criteria were less than 6 weeks of pain duration, cauda equina compromise, foraminal or extra-foraminal herniations, spinal stenosis, malignancy, previous spinal surgery, spinal deformity, concurrent infection and rheumatic disease. Surgery and follow-up were made at a single Institution. A biomedical researcher independently collected and reviewed the data. ODI, back and leg VAS and SF-36 were the outcome measures used preoperatively, postoperatively and at 6-, 12- and 24-month follow-up. 212/240 (91%) patients completed the 24-month follow-up period. VAS back and leg, ODI and SF36 scores showed clinically and statistically significant improvements within groups without significant difference among groups throughout follow-up. Dural tears, root injuries and recurrent herniations were significantly more common in group 1. Wound infections were similar in group 2 and 3, but did not affect patients in group 1. Overall costs were significantly higher in group 1 and lower in group 3. In conclusion, outcome measures are equivalent 2 years following lumbar discectomy with micro-endoscopy, microscopy or open technique, but severe complications are more likely and costs higher with micro-endoscopy. PMID:20127495

  7. Accretion discs

    NASA Astrophysics Data System (ADS)

    Abramowicz, Marek A.; Straub, Odele

    2014-08-01

    Accretion discs are flattened astronomical objects made of rapidly rotating gas which slowly spirals onto a central gravitating body. The gravitational energy of infalling matter extracted in accretion discs powers stellar binaries, active galactic nuclei, proto-planetary discs and some gamma-ray bursts. The black hole accretion in quasars is the most powerful and efficient stationary engine known in the universe. In accretion discs the high angular momentum of rotating matter is gradually transported outwards by stresses (related to turbulence, viscosity, shear and magnetic fields). This gradual loss of angular momentum allows matter to progressively move inwards, towards the centre of gravity. The gravitational energy of the gaseous matter is thereby converted to heat. A fraction of the heat is converted into radiation, which partially escapes and cools down the accretion disc. Accretion disc physics is thus governed by a non-linear combination of many processes, includ! ing gravity, hydrodynamics, viscosity, radiation and magnetic fields.

  8. Lifestyle factors and lumbar disc disease: results of a German multi-center case-control study (EPILIFT)

    PubMed Central

    2010-01-01

    Introduction In the large-scale case-control study EPILIFT, we investigated the dose-response relationship between lifestyle factors (weight, smoking amount, cumulative duration of different sports activities) and lumbar disc disease. Methods In four German study regions (Frankfurt am Main, Freiburg, Halle/Saale, Regensburg), 564 male and female patients with lumbar disc herniation and 351 patients with lumbar disc narrowing (chondrosis) aged 25 to 70 years were prospectively recruited. From the regional population registers, 901 population control subjects were randomly selected. In a structured personal interview, we enquired as to body weight at different ages, body height, cumulative smoking amount and cumulative duration of different sports activities. Confounders were selected according to biological plausibility and to the change-in-estimate criterion. Adjusted, gender-stratified odds ratios with 95% confidence intervals were calculated using unconditional logistic regression analysis. Results The results of this case-control study reveal a positive association between weight and lumbar disc herniation as well as lumbar disc narrowing among men and women. A medium amount of pack-years was associated with lumbar disc herniation and narrowing in men and women. A non-significantly lowered risk of lumbar disc disease was found in men with high levels of cumulative body building and strength training. Conclusions According to our multi-center case-control study, body weight might be related to lumbar disc herniation as well as to lumbar disc narrowing. Further research should clarify the potential protective role of body building or strength training on lumbar disc disease. PMID:20955546

  9. The Etiologies of Low Back Pain in Patients With Lumbar Disk Herniation

    PubMed Central

    Samini, Fariborz; Gharedaghi, Mohammad; Khajavi, Mahdi; Samini, Mohammad

    2014-01-01

    Background: Low back pain (LBP) is a common complaint in population that lowers the quality of life. The main etiology of LBP is recognized in about 20% of patients while it is attributed to lumbar disk herniation (LDH) in 80% of cases and causes some unnecessary lumbar surgeries without realizing the definite cause. Objectives: This study was planned to evaluate the etiologies of LBP in patients who had LDH to clarify whether the disc herniation is the main cause of patients` pain or other diseases were responsible for this kind of pain. Materials and Methods: In this cross-sectional study, we analyzed the medical profiles of the patients with proven LDH in a private clinic in Mashhad City, Iran, between 2005 and 2012, for demographic and the etiologies of LBP with clinical and paraclinical studies. We also calculated the incidence of each etiology by SPSS 13. Results: In our study, among 1250 patients with proven LDH by MRI, 500 patients (40%) had chronic LBP and the most common causes of LBP were heavy constant working (40.2%), osteoporosis (35.6%), and sacroiliac joint pain (34.6%), consecutively. Interestingly, LDH had the ninth rank among the common cause of LBP. Conclusions: In this study, we found that in spite of previous beliefs, discopathies were not common etiologies of LBP. Thus, even in patients with proven LDH by imaging studies, the physician should perform a thorough evaluation for other causes of LBP to avoid unnecessary lumbar surgeries. PMID:25763198

  10. An Unappreciated Correlation : Surgical Treatment of Lumbosacral Disc Disease and Erectile Dysfunction

    PubMed Central

    Kulaksizoglu, Haluk

    2010-01-01

    Objective The aim of the present study was to assess the effect of lumbar disc herniation surgery for low back pain on the erectile functioning. Methods Thirty-eight patients, with age ranging from 22 to 56 years, who had presented with pain due to herniated lumbar discs were included in the study. International Index of Erectile Function (IIEF) Short Form questionnaire was used to evaluate the erectile functioning. Patient visits on the 1st week,1st month and 3rd month postoperatively were analyzed. Pain scores were also noted together with side effects and the complications of the surgery. Results Of the 38 patients, 18 patients had reported erectile dysfunction; 10 patients mild and 8 patients moderate erectile dysfunction. Twenty patients did not report erectile problems. The herniation levels mostly were L5-S1 in 12 (31.6%). Overall, erectile dysfunction rates have improved in 31.7% of those previously with erectile dysfunction in a 3 month period after the surgery. Best results were obtained in those patients with mild erectile dysfunction preoperatively. Conclusion Mild erectile dysfunction together with radiculopathy tends to improve after lumbosacral disc surgery. Moderate and severe erectile dysfunction may be related to a more severe nerve injury or to vascular and/or psychiatric factors. An evaluation of erectile functioning should routinely be performed in patients with lumbosacral disc disease both for data accumulation and for medico legal causes since the documentation of the correlation between erectile dysfunction and lumbosacral disc disease is still lacking. PMID:20461169

  11. Role of Cytokines in Intervertebral Disc Degeneration: Pain and Disc-content

    PubMed Central

    Risbud, Makarand V.; Shapiro, Irving. M

    2014-01-01

    Degeneration of the intervertebral disc is the major contributor to back/neck and radicular pain. It is characterized by an elevation in levels of the inflammatory cytokines tumor necrosis factor (TNF)-?, interleukin (IL)-1 ?/?, IL-6 and IL-17 secreted by the disc cells themselves; these cytokines promote matrix degradation, chemokine production and changes in cell phenotype. The resulting imbalance between catabolic and anabolic responses leads to degeneration, as well as herniation and radicular pain. Release of chemokines from degenerating discs promote infiltration and activation of T and B cells, macrophages, neutrophils, and mast cells further amplifying the inflammatory cascade. Immunocyte migration into the disc is accompanied by the appearance of microvasculature and nerve fibers arising from the dorsal root ganglion (DRG). In this inflammatory milieu, neurogenic factors in particular nerve growth factor (NGF) and brain-derive neurotrophic factor (BDNF) generated by disc and immune cells induce expression of pain associated cation channels in DRGs. Depolarization of these channels is likely to promote discogenic and radicular pain and reinforce the cytokine-mediated degenerative cascade. Taken together, the enhanced understanding of the contribution of cytokines and immune cells to catabolic and nociceptive processes provide new targets for treating symptomatic disc disease. PMID:24166242

  12. DETAIL OF DENVER DISC FILTER IN CO91107, SUCTION END. NOTE ...

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

    DETAIL OF DENVER DISC FILTER IN CO-91-107, SUCTION END. NOTE BEARING HOUSING WITH CAST LOGO, SUCTION PIPE GOING OFF TO THE RIGHT, AND FILTER DISC IN BACKGROUND. VACUUM INSIDE DISCS FURTHER DEWATERED CONCENTRATE. AS DISC SLOWLY ROTATED A BAR SCRAPED DRIED CONCENTRATE FROM OUTSIDE OF FILTER CLOTH. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

  13. Correlation between clinical features and magnetic resonance imaging findings in lumbar disc prolapse

    PubMed Central

    Janardhana, Aithala P; Rajagopal; Rao, Sharath; Kamath, Asha

    2010-01-01

    Background: Lumbar disc prolapse is one of the common causes of low back pain seen in the working population. There are contradictorty reports regarding the clinical significance of various magnetic resonance imaging (MRI) findings observed in these patients. The study was conducted to correlate the abnormalities observed on MRI and clinical features of lumbar disc prolapse. Materials and Methods: 119 clinically diagnosed patients with lumbar disc prolapse were included in the study. Clinical evaluation included pain distribution, neurological symptoms and signs. MR evaluation included grades of disc degeneration, type of herniation, neural foramen compromise, nerve root compression, and miscellaneous findings. These MRI findings were tested for inter- and intraobserver variability. The MRI findings were then correlated with clinical symptoms and the level of disc prolapse as well as neurological signs and symptoms. Statistical analysis included the Kappa coefficient, Odd’s ratio, and logistic regression analysis. Results: There were no significant inter- or intraobserver variations for most of MRI findings (Kappa value more than 0.5) except for type of disc herniation which showed a interobserver variation of 0.46 (Kappa value). The clinical level of pain distribution correlated well with the MRI level (Kappa 0.8), but not all disc bulges produced symptoms. Central bulges and disc protrusions with thecal sac compression were mostly asymptomatic, while centrolateral protrusions and extrusions with neural foramen compromise correlated well with the dermatomal distribution of pain. Root compression observed in MRI did not produce neurological symptoms or deficits in all patients but when deficits were present, they correlated well with the presence of root compression in MRI. Multiple level disc herniations with foramen compromise were strongly associated with the presence of neurological signs. Conclusions: The presence of centrolateral protrusion or extrusion with gross foramen compromise correlates with clinical signs and symptoms very well, while central bulges and disc protrusions correlate poorly with clinical signs and symptoms. The presence of neural foramen compromise is more important in determining the clinical signs and symptoms while type of disc herniation (bulge, protrusion, or extrusion) correlates poorly with clinical signs and symptoms. PMID:20697478

  14. Minimally invasive techniques for the treatment of intervertebral disk herniation.

    PubMed

    Mathews, Hallett H; Long, Brenda H

    2002-01-01

    Hemilaminectomy with diskectomy, the original surgical option to address intervertebral disk herniation, was superseded by open microdiskectomy, a less invasive technique recognized as the surgical benchmark with which minimally invasive spine surgery techniques have been compared as they have been developed. These minimally invasive surgical techniques for patients with herniated nucleus pulposus and radiculopathy include laser disk decompression, arthroscopic microdiskectomy, laparoscopic techniques, foraminal endoscopy, and microendoscopic diskectomy. Each has its own complications and requires a long learning curve to develop familiarity with the technique. Patient selection, and especially disk morphology, are the most important factors in choice of technique. The optimal candidate has a previously untreated single-level herniation with limited migration or sequestration of free fragments. PMID:11929202

  15. Spontaneous disappearance of lumbar disk herniation within 3 months.

    PubMed

    Nozawa, Satoshi; Nozawa, Asae; Kojima, Hisashi; Shimizu, Katsuji

    2009-11-01

    Although spontaneous regression of disk herniation is a well-known phenomenon, the time taken for the condition to resolve has not been detailed in previous studies. This article describes a case of vanishing lumbar disk herniation in a 33-year-old man. The patient experienced sudden severe lumbar pain while lifting a 240-kg weight while attempting a Donkey Calf Raise during muscle training. The pain persisted despite the use of a lumbar corset and nonsteroidal anti-inflammatory drugs. Twelve days after onset, sensory disturbance appeared in the right L5 dermatome, and a manual muscle test of the right anterior tibial muscle revealed level 3. The pain gradually spread over the right lower extremity and the indistinct lumbago changed to localized back pain at the L4/5 vertebral level. Magnetic resonance imaging (MRI) of the lumbar spine 12 days after onset revealed a large disk herniation at L4/5. T2-weighted images demonstrated the herniated disk with a sequestrated disk fragment, which compressed the right L5 nerve root. Over the following month, his pain gradually diminished and he was able to resume his muscle-building program. Follow-up MRI 3 months after the lumbar injury showed complete disappearance of the extruded disk material. This is the first reported case of disk herniation that disappeared within only 3 months, as previous reports have reported that a minimum 30-week period was needed. Clinical awareness of the possibility that disk herniation may resolve within a relatively short time may aid both correct informed consent and treatment. PMID:19902881

  16. Clinical correlation of magnetic resonance imaging with symptom complex in prolapsed intervertebral disc disease: A cross-sectional double blind analysis

    PubMed Central

    Bajpai, Jeetendra; Saini, Sumit; Singh, Rakhi

    2013-01-01

    Introduction: Low backache (LBA) is one of the most common problems and herniated lumbar disc is one of the most commonly diagnosed abnormalities associated with LBA. Disc herniation of the same size may be asymptomatic in one patient and can lead to severe nerve root compromise in another patient. Objective: To evaluate correlation between the clinical features of disc collapse and magnetic resonance imaging (MRI) finding to determine the clinical importance of anatomical abnormalities identified by MRI technique. Summary: From January 2010 to January 2012, 75 otherwise healthy patients (43 males 32 females) between the age of 19 and 55 years (average age was 44.5 years) with low back pain and predominant complaint of root pain who presented to our clinic were included in the study. Materials and Methods: Proper screening was done to rule out previous spine affection and subjected to MRI. Results: The results were analyzed under four headings viz. disc herniation, disc degeneration, thecal sac deformation and neural foramen effacement. All patients had a visual analog score (VAS) score more than 6. The interrater correlation coefficient kappa was calculated to be k=0.51. There were total 44 patients with herniation, 25 patients had mild, one patient had moderate degree of thecal sac deformation, 21 patients had one or more levels of foraminal effacement by the herniated tissue, 100% of the patients had disc degeneration ranging from grade 1 to 3 at different levels; and 48 patients (64%) had radiculopathy, six (8%) patients had bilateral and others had ipsilateral affection. Conclusion: In our study, the correlation was made between clinical findings and MRI findings. It can safely be concluded that treating physician should put more emphasis on history, clinical examination, and make the inference by these and then should correlate the clinical findings with that of MRI to reach a final diagnosis. PMID:24381451

  17. Disc protrusion in the childParticular features and comparison with neoplasms

    Microsoft Academic Search

    Juan F. Martínez-Lage; Antonio Martínez-Robledo; Francisco López; Máximo Poza

    1997-01-01

    Lumbar intervertebral disc herniation, although common in adults, is infrequent in the young, and especially in patients\\u000a under 17 years old. In this work we review clinical data pertaining to two pediatric groups of patients whose main complaint\\u000a was low back pain and\\/or sciatica, trying to identify factors that might contribute to their earlier referral and to the differential\\u000a diagnosis

  18. Needle puncture injury of the rat intervertebral disc affects torsional and compressive biomechanics differently

    Microsoft Academic Search

    Arthur J. Michalek; Kristin L. Funabashi; James C. Iatridis

    2010-01-01

    Needle puncture is a common method of inducing intervertebral disc (IVD) degeneration in small animal models and may have\\u000a some similarities to IVD injury conditions such as herniation. Yet, the influence of puncture injuries on IVD biomechanics\\u000a is not well understood. This study quantified the acute effects of anular injury on the biomechanics of rat caudal IVDs in\\u000a compression and

  19. Intervertebral Disc Calcification in Childhood – A Case Report and Review of the Literature

    Microsoft Academic Search

    R. Gerlach; M. Zimmermann; S. Kellermann; R. Lietz; A. Raabe; V. Seifert

    2001-01-01

    Summary  ?The authors report the case of a 10-year-old girl with intervertebral disc calcifications from the levels C6\\/C7 to Th1\\/Th2,\\u000a presenting with a herniated calcified intervertebral disc at the C7\\/Th1 level, causing spinal cord compression with subsequent\\u000a progressive paresis and sensory loss of her left leg. After anterior cervical discectomy and fusion the neurological deficits\\u000a completely resolved within 2 weeks. It

  20. D-Zero Cryostat Supplemental Rupture Disc

    SciTech Connect

    Mulholland, G.T.; /Fermilab

    1987-08-03

    The common relief and rupture disc vent line requires a double disc assembly with vented interspace for accurate disc burst pressures. The first disc must take pump and purge vacuum loading, but be set to operate at 110% of the MAWP, 18.3 psig (ASME code). The available solution is 18.3 psig with a burst tolerance of +/- psig. The interspace should be locally vented by a flow limiting vent valve to decouple the vent line backpressure from the vessel rupture disc. The second disc must take the worst case vent line backpressure, the steady state value found in D-Zero engineering note 3740.000-EN-63 with all three cryostats simultaneously venting at the fire condition into the 4-inch x 6-inch and 6-inch x 8-inch sections. This value is less than 2 psid. The maximum rupture value for the second disc must be less than the minimum rupture value for the first disc less 2 psid i.e. < 16.3.

  1. Brain herniations into the dural venous sinuses or calvarium: MRI of a recently recognized entity.

    PubMed

    Battal, Bilal; Castillo, Mauricio

    2014-02-01

    Brain herniations into dural venous sinuses (DVS) are rare findings recently described and their etiology and clinical significance are controversial. We describe five patients with brain herniations into the DVS or calvarium identified on MRI, and discuss their imaging findings, possible causes, and relationship to the patient's symptoms. All patients were examined with MRI including high resolution pre- and post-contrast T1- and T2-weighted sequences. With respect to brain herniations we documented their locations, signal intensities in different sequences, and size. We then reviewed clinical records in an attempt to establish if any symptoms were related to the presence of these herniations. Three males and two females were examined (age range, 11-68 years). Three patients had unilateral temporal lobe herniations into transverse sinuses, one had a cerebellar herniation into the skull, and one had bilateral temporal lobe herniations into the transverse sinuses as well as a cerebellar herniation into the sigmoid sinus. In all, the herniated brain and surrounding cerebrospinal fluid (CSF) had normal signal intensity on all MRI sequences. When correlated with clinical symptoms, brain herniations were thought to be incidental and asymptomatic in three patients and two patients had histories of headaches. Brain herniations with surrounding CSF into the DVS/skull should be considered potential sources of filling defects in the DVS. We believe that they are probably incidental findings that may be more common than previously recognized and should be not confused with the more common arachnoid granulations, clots, or tumors. Two patients had headaches, but their relation to the presence of herniated brain was uncertain. PMID:24571834

  2. Asymptomatic tonsillar herniation in a neonate with cleidocranial dysplasia.

    PubMed

    Myers, Kenneth A; Thomas, Mary Ann; Wei, Xing-Chang; Scantlebury, Morris H

    2014-02-01

    A male neonate was antenatally diagnosed with cleidocranial dysplasia on the basis of prenatal ultrasound findings and molecular testing of the RUNX2 gene. The patient presented with urosepsis at 24 days of life and subsequently developed apneas after endoscopic examination of the vocal cords. Computed tomography and MRI studies of the head revealed crowding of the posterior fossa with tonsillar and uncal herniation. Apneas were initially thought to be related to brainstem compression; however, the patient responded immediately to caffeine and subsequently stabilized with antibiotic therapy. To our knowledge, this is the first published MRI study of the brain of a neonate with cleidocranial dysplasia to demonstrate the striking posterior fossa findings seen secondary to the reduced bony skull structures. However, despite the dramatic herniation, brainstem function was not compromised. PMID:24446448

  3. Seat Belt-Related Chondrosternal Disruption With Lung Herniation

    Microsoft Academic Search

    David Rice; Naveen Bikkasani; Raphael Espada; Kenneth Mattox; Matthew Wall

    eat belt-related injuries have been well characterized and predominately involve the intraabdominal or- gans. Significant injury to the chest wall, cervical vascu- lature, and intrathoracic structures is infrequent, how- ever. We report a case of severe chest wall injury with resulting lung herniation after a motor vehicle accident in which the driver was restrained. A 54-year-old 270-lb male was a

  4. Herniation through the foramen of Morgagni: early diagnosis and treatment

    Microsoft Academic Search

    Ahmed H. Al-Salem; Akhter Nawaz; Hilal Matta; Alic Jacobsz

    2002-01-01

    The majority of congenital diaphragmatic hernias (CDH) occur through the foramen of Bochdalek; herniation through the foramen\\u000a of Morgagni (MH) is rare. Fifteen children (12 males and 3 females) with congenital MH (7 right, 3 left, 5 bilateral) were\\u000a treated over a period of 15 years, comprising 11% of a total of 135 children with different types of CDH. The

  5. Endoscopic transsphenoidal treatment of a prolactinoma patient with brain and optic chiasmal herniations.

    PubMed

    Zhang, Ning; Guo, Liemei; Ge, Jianwei; Qiu, Yongming

    2014-05-01

    Bromocriptine has been the most widely used and effective agent to treat macroprolactinoma, and chiasmal herniation in a macroprolactinoma patient following the treatment with bromocriptine is a well-recognized complication. However, herniation of the inferior mesial frontal lobe into the sella has been rarely reported. The present clinical report is the second radiographic demonstration of herniation of the inferior mesial frontal lobe into the sella. After the treatment with transsphenoidal endoscopic chiasmopexy, the patient's visual disturbance improved dramatically. We suggest that transsphenoidal endoscopic chiasmopexy is an effective treatment option for the prolactinoma patient with brain and chiasmal herniations following the treatment with bromocriptine. PMID:24820730

  6. Transforaminal Approach in Thoracal Disc Pathologies: Transforaminal Microdiscectomy Technique

    PubMed Central

    Dalbayrak, Sedat; Öztürk, Kadir; Y?lmaz, Mesut; Gökda?, Mahmut; Ayten, Murat

    2014-01-01

    Objective. Many surgical approaches have been defined and implemented in the last few decades for thoracic disc herniations. The endoscopic foraminal approach in foraminal, lateral, and far lateral disc hernias is a contemporary minimal invasive approach. This study was performed to show that the approach is possible using the microscope without an endoscope, and even the intervention on the discs within the spinal canal is possible by having access through the foramen. Methods. Forty-two cases with disc hernias in the medial of the pedicle were included in this study; surgeries were performed with transforaminal approach and microsurgically. Extraforaminal disc hernias were not included in the study. Access was made through the Kambin triangle, foramen was enlarged, and spinal canal was entered. Results. The procedure took 65 minutes in the average, and the mean bleeding amount was about 100cc. They were mobilized within the same day postoperatively. No complications were seen. Follow-up periods range between 5 and 84 months, and the mean follow-up period is 30.2 months. Conclusion. Transforaminal microdiscectomy is a method that can be performed in any clinic with standard spinal surgery equipment. It does not require additional equipment or high costs. PMID:24839557

  7. Autotraction versus passive traction: an open controlled study in lumbar disc herniation.

    PubMed

    Tesio, L; Merlo, A

    1993-08-01

    Autotraction (AT) is a treatment for low-back pain syndrome of benign etiology that uses a specially designed traction table divided into two movable sections. While lying on the table, the pelvis secured, the patient controls the traction forces by grasping and pulling the bars at the head of the table. There are controls for the therapist to apply, through movable sections of the table, rotation and bending forces to help restore mobility to the lumbar spine without inducing pain. The present study is based upon a randomized treatment trial comparing conventional passive traction (PT) to AT. The following outcome indicators were used: (1) subjective response concerning overall improvement, (2) pain intensity (visual analog scale, 0-100), (3) qualitative pain severity (McGill Pain Questionnaire, short-form, 0-45), and (4) pain related disability (Oswestry Low Back Pain Disability Score, 0-100). The favorable response to AT was 75% (30 of the 40 patients) versus the 22% (6 of 27 patients) to PT (p < 0.001). After 3 months, 19 of the 30 responders to AT (63%) reported continued improvement. In these patients, pain ratings remained stable and the disability scores decreased to 0 to 23% of the pretreatment value (median and mean respectively, p < 0.001). PMID:8347073

  8. Central nervous system lesions and cervical disc herniations in amateur divers

    Microsoft Academic Search

    J Reul; A Jung; A Thron; J Weis; K Willmes

    1995-01-01

    Permanent neuropsychological changes such as memory disturbances and depression have been found in professional divers, even in those who have never had decompression sickness. The changes are probably the result of intravascular gas bubbles insufficient to cause acute symptoms. We examined amateur divers with long histories of self-contained underwater breathing apparatus diving by magnetic resonance imaging and compared them with

  9. Anterior cervical fusion using porous hydroxyapatite ceramics for cervical disc herniation

    Microsoft Academic Search

    Futoshi Suetsuna; Toru Yokoyama; Eiji Kenuka; Seiko Harata

    2001-01-01

    Background context: The Smith-Robinson Method (SR), which employs autogenous bone, is the current standard for anterior cervical fusion (AF) surgery. However, autogenous bone has graft-related complications and morbidity, and harvesting it increases trauma and risk to the patient. The use of hydroxyapatite ceramic (HAP) inserts may provide a superior alternative.Purpose: To determine the efficacy of using HAP in AF.Study design\\/setting:

  10. Strain in fibers of a lumbar disc. Analysis of the role of lifting in producing disc prolapse.

    PubMed

    Shirazi-Adl, A

    1989-01-01

    A three-dimensional nonlinear finite element model has been used to predict the strain in the disc fibers of a lumbar motion segment under various single and combined loads such as those representing symmetric and non-symmetric liftings. A progressive failure analysis also has been performed under loads representing lifting while bending to one side: assuming yield and ultimate fiber strains of 14 and 16%, respectively. Large tensile strains of about 10% in the disc fibers are predicted under the maximum loads simulating symmetric lifting. Addition of lateral bending and twisting significantly increases the maximum fiber strain to more than 20%, and hence augments the risk for disc rupture. The maximum fiber strain occurs in the innermost annulus layer at the posterolateral location. Loss of intradiscal pressure or volume has a marked diminishing effect on the magnitude of maximum fiber strain predicted under flexion loadings. Failure analysis indicates that rupture initiates in the fibers in the innermost layer at the posterolateral location. With a slight increase in the loads, rupture progresses radially to the adjacent outer layer. Further progress of rupture in the fibers toward the annulus outer periphery resulting in complete radial fissure and disc prolapse appears to require additional increase in the loads. In the presence of large intradiscal pressure, the generated partial or complete radial fissure is likely to result in annulus protrusion or disc herniation, respectively. The results of clinical, epidemiologic, and experimental studies support the failure mechanism predicted in the present study. PMID:2913676

  11. Non-reclosing pressure relief device for vacuum systems

    DOEpatents

    Swansiger, William A. (Livermore, CA)

    1994-01-01

    A non-reclosing overpressure protection device such as a rupture disc provides a non-reclosing opening upon forcible contact with a knife blade. A bellows, having an inlet capable of being sealably connected to a source of pressure (the vacuum system) and an outlet containing the rupture disc, transmits the pressure in the system to the disc. The bellows maintains the disc away from the knife when the pressure is below an overpressure amount, and carries the disc to a position when the pressure is above an overpressure amount where the disc is ruptured by the knife.

  12. Uncal herniation in a fully conscious patient-The sliding uncus syndrome.

    PubMed

    Katzir, Miki; Attia, Moshe; Sviri, Gill E; Zaaroor, Menashe

    2015-04-01

    Uncal herniation is accompanied by a decreased level of consciousness. We describe a patient who remained fully alert despite the uncal herniation. The computed tomography (CT) scans allowed us to visualize the uncus and its spatial relation to the cerebral peduncle. We describe the sliding uncus syndrome. PMID:25375327

  13. Potential regenerative treatment strategies for intervertebral disc degeneration in dogs

    PubMed Central

    2014-01-01

    Pain due to spontaneous intervertebral disc (IVD) disease is common in dogs. In chondrodystrophic (CD) dogs, IVD disease typically develops in the cervical or thoracolumbar spine at about 3–7 years of age, whereas in non-chondrodystrophic (NCD) dogs, it usually develops in the caudal cervical or lumbosacral spine at about 6–8 years of age. IVD degeneration is characterized by changes in the biochemical composition and mechanical integrity of the IVD. In the degenerated IVD, the content of glycosaminoglycan (GAG, a proteoglycan side chain) decreases and that of denatured collagen increases. Dehydration leads to tearing of the annulus fibrosus (AF) and/or disc herniation, which is clinically characterized by pain and/or neurological signs. Current treatments (physiotherapy, anti-inflammatory/analgesic medication, surgery) for IVD disease may resolve neurological deficits and reduce pain (although in many cases insufficient), but do not lead to repair of the degenerated disc. For this reason, there is interest in new regenerative therapies that can repair the degenerated disc matrix, resulting in restoration of the biomechanical function of the IVD. CD dogs are considered a suitable animal model for human IVD degeneration because of their spontaneous IVD degeneration, and therefore studies investigating cell-, growth factor-, and/or gene therapy-based regenerative therapies with this model provide information relevant to both human and canine patients. The aim of this article is to review potential regenerative treatment strategies for canine IVD degeneration, with specific emphasis on cell-based strategies. PMID:24387033

  14. Left Diaphragmatic Herniation following Orthotopic Liver Transplantation in an Adult

    PubMed Central

    Rosat, Adriá; Alonso, Ayaya; Padilla, Javier; Sanz, Pablo; Varona, M. Aránzazu; Méndiz, Javier; Moneva, Enrique; Barrera, Manuel

    2015-01-01

    Diaphragmatic herniation is an uncommon complication in the postquirurgic follow of the liver transplant. The associated symptoms are unspecific and may not suggest the correct diagnosis. It may explain why in many patients the diagnosis remains unmade or it is made only after a long interval of time. We present the case of a fifty-seven-year-old male who required an orthotopic liver transplant in 2010 due to a trifocal hepatocarcinoma. In postoperatory follow-up the patient showed alimentary regurgitation, vomiting, and dyspepsia. The diagnosis was made by an oesophagogastroduodenal transit with barium and an abdominal CT scan that showed a left diaphragmatic herniation with the gastric fundus into the thorax. With these findings we decided to perform a programmed surgery. After takedown of adhesions and replacement of the stomach into the upper abdomen, the palm-sized diaphragmatic opening was closed with a synthetic material. The patient's condition remained stable throughout the entire operation. The postoperative course was uneventful and he was discharged at the fifth day after surgery with a normal digestive intake. In a 12-month follow-up the patient shows no symptoms.

  15. Automotive disc brake squeal

    Microsoft Academic Search

    N. M. Kinkaid; O. M. O'Reilly; P. Papadopoulos

    2003-01-01

    Disc brake squeal remains an elusive problem in the automotive industry. Since the early 20th century, many investigators have examined the problem with experimental, analytical, and computational techniques, but there is as yet no method to completely suppress disc brake squeal. This paper provides a comprehensive review and bibliography of works on disc brake squeal. In an effort to make

  16. Turbine disc sealing assembly

    DOEpatents

    Diakunchak, Ihor S.

    2013-03-05

    A disc seal assembly for use in a turbine engine. The disc seal assembly includes a plurality of outwardly extending sealing flange members that define a plurality of fluid pockets. The sealing flange members define a labyrinth flow path therebetween to limit leakage between a hot gas path and a disc cavity in the turbine engine.

  17. Gradual disc prolapse.

    PubMed

    Adams, M A; Hutton, W C

    1985-01-01

    Fifty-two cadaveric lumbar motion segments were subjected to fatigue loading in compression and bending to determine if the intervertebral discs could prolapse in a gradual manner. Prior to testing, the nucleus pulposus of each disc was stained with a small quantity of blue dye and radiopaque solution. This enabled the progress of any gradual prolapse to be monitored by direct observation and by discogram. Six discs developed a gradual prolapse during the testing period. The injury starts with the lamellae of the annulus being distorted to form radial fissures and then nuclear pulp is extruded from the disc and leaks into the spinal canal. Discs most commonly affected were from the lower lumbar spine of young cadavers. Tests on ten older discs with pre-existing ruptures showed that such discs are stable and do not leak nuclear pulp. PMID:4081867

  18. Diaphragmatic Herniation through Prosthetic Material after Extrapleural Pneumonectomy: Be Aware of Tumor Recurrence

    PubMed Central

    Pop, Daniel; Cohen, Charlotte; Schneck, Anne-Sophie; Nadeemy, Ahmad S.; Venissac, Nicolas; Mouroux, Jerome

    2013-01-01

    Extrapleural pneumonectomy (EPP) is indicated in selected group of patients with pleural mesothelioma. Diaphragmatic reconstruction represents a part of this complex operation. We present the case of a late diaphragmatic gastric herniation through prosthetic material after EPP. PMID:25360411

  19. Surgical vs Nonoperative Treatment for Lumbar Disk Herniation

    PubMed Central

    Weinstein, James N.; Tosteson, Tor D.; Lurie, Jon D.; Tosteson, Anna N. A.; Hanscom, Brett; Skinner, Jonathan S.; Abdu, William A.; Hilibrand, Alan S.; Boden, Scott D.; Deyo, Richard A.

    2008-01-01

    Context Lumbar diskectomy is the most common surgical procedure performed for back and leg symptoms in US patients, but the efficacy of the procedure relative to nonoperative care remains controversial. Objective To assess the efficacy of surgery for lumbar intervertebral disk herniation. Design, Setting, and Patients The Spine Patient Outcomes Research Trial, a randomized clinical trial enrolling patients between March 2000 and November 2004 from 13 multidisciplinary spine clinics in 11 US states. Patients were 501 surgical candidates (mean age, 42 years; 42% women) with imaging-confirmed lumbar intervertebral disk herniation and persistent signs and symptoms of radiculopathy for at least 6 weeks. Interventions Standard open diskectomy vs nonoperative treatment individualized to the patient. Main Outcome Measures Primary outcomes were changes from baseline for the Medical Outcomes Study 36-item Short-Form Health Survey bodily pain and physical function scales and the modified Oswestry Disability Index (American Academy of Orthopaedic Surgeons MODEMS version) at 6 weeks, 3 months, 6 months, and 1 and 2 years from enrollment. Secondary outcomes included sciatica severity as measured by the Sciatica Bothersomeness Index, satisfaction with symptoms, self-reported improvement, and employment status. Results Adherence to assigned treatment was limited: 50% of patients assigned to surgery received surgery within 3 months of enrollment, while 30% of those assigned to nonoperative treatment received surgery in the same period. Intent-to-treat analyses demonstrated substantial improvements for all primary and secondary outcomes in both treatment groups. Between-group differences in improvements were consistently in favor of surgery for all periods but were small and not statistically significant for the primary outcomes. Conclusions Patients in both the surgery and the nonoperative treatment groups improved substantially over a 2-year period. Because of the large numbers of patients who crossed over in both directions, conclusions about the superiority or equivalence of the treatments are not warranted based on the intent-to-treat analysis. Trial Registration clinicaltrials.gov Identifier: NCT00000410 PMID:17119140

  20. Tegmen Tympani Defect and Brain Herniation Secondary to Mastoid Surgery: Case Presentation

    PubMed Central

    Egilmez, Oguz Kadir; Hanege, Fatih Mehmet; Kalcioglu, M. Tayyar; Kaner, Tuncay; Kokten, Numan

    2014-01-01

    Brain herniation into the middle ear is very rarely seen. In addition to reasons like congenital factors, trauma, and infection, tegmen defect may develop as a result of iatrogenic events secondary to chronic otitis media surgery with or without cholesteatoma. Since it may cause life-threatening complications, patients must be evaluated and monitored for tegmen defect. In this paper, diagnosis and treatment of a brain herniation case due to iatrogenic tegmen defect were described along with relevant literature. PMID:25140266

  1. Radially truncated galactic discs

    E-print Network

    Richard de Grijs; Michiel Kregel; Karen H. Wesson

    2001-02-02

    We present the first results of a systematic analysis of radially truncated exponential discs for four galaxies of a complete sample of disc-dominated edge-on spiral galaxies. The discs of our sample galaxies are truncated at similar radii on either side of their centres. With possible the exception of the disc of ESO 416-G25, it appears that the truncations in our sample galaxies are closely symmetric, in terms of both their sharpness and the truncation length. However, the truncations occur over a larger region and not as abruptly as found in previous studies. We show that the truncated luminosity distributions of our sample galaxies, if also present in the mass distributions, comfortably meet the requirements for longevity. The formation and maintenance of disc truncations are likely closely related to stability requirements for galactic discs.

  2. Traumatic herniation of buccal fat pad in 1 year old child: case report and review of literature.

    PubMed

    Gadipelly, Srinivas; Sudheer, M V S; Neshangi, Srisha; Harsha, G; Reddy, Vijaybaskar

    2015-03-01

    Traumatic herniation of buccal fat pad (BFP) is very rare, usually seen in infants and young children ranging from 5 months to 12 years of age. Etiology will be blunt injury to buccal mucosa from foreign objects or trauma due to teeth and fall. The suckling activity in infants may also encourage the herniation following trauma. A minor injury or perforation to the buccal mucosa can cause herniation of BFP. The size of herniated mass is very large when compared to the size of the perforation. The history of trauma, absence of prolapse before the injury, its occurrence in infants and young children, specific anatomic sites and location of perforation in mucosa, histopathological appearance of adipose tissue are the characteristic features important for diagnosing the condition. The treatment options for the herniated BFP are usually excision. Alternative to excision is repositioning of the herniated fat in its anatomical location if noticed early. PMID:25848153

  3. Tissue-engineered intervertebral discs produce new matrix, maintain disc height, and restore biomechanical function to the rodent spine

    PubMed Central

    Bowles, Robby D.; Gebhard, Harry H.; Härtl, Roger; Bonassar, Lawrence J.

    2011-01-01

    Lower back and neck pain are leading physical conditions for which patients see their doctors in the United States. The organ commonly implicated in this condition is the intervertebral disc (IVD), which frequently herniates, ruptures, or tears, often causing pain and limiting spinal mobility. To date, approaches for replacement of diseased IVD have been confined to purely mechanical devices designed to either eliminate or enable flexibility of the diseased motion segment. Here we present the evaluation of a living, tissue-engineered IVD composed of a gelatinous nucleus pulposus surrounded by an aligned collagenous annulus fibrosus in the caudal spine of athymic rats for up to 6 mo. When implanted into the rat caudal spine, tissue-engineered IVD maintained disc space height, produced de novo extracellular matrix, and integrated into the spine, yielding an intact motion segment with dynamic mechanical properties similar to that of native IVD. These studies demonstrate the feasibility of engineering a functional spinal motion segment and represent a critical step in developing biological therapies for degenerative disc disease. PMID:21808048

  4. A Study on Dispersion and Rate of Fat Infiltration in the Lumbar Spine of Patients with Herniated Nucleus Polpusus

    PubMed Central

    Kong, Bong-jun; Lim, Jong-soo; Kim, Kyung

    2014-01-01

    [Purpose] This study investigated the relationship between herniated nucleus pulposus (HNP) and fat infiltration of muscles around the spine by measuring body mass index (BMI) and fat infiltration of the muscles around the spine. [Subjects and Methods] Subjects were 82 people, both men and women they were divided into two groups, a normal group and a patient group who were suffering from serious HNP between L4 and L5. Of the anthropometric measurement, and fat infiltration muscles by measuring the cross-sectional area from the center of the disc to the muscle around the spine and the cross-sectional area of fat infiltration. [Results] Fat infiltration rate of each lumbar layer in the normal group was different L34–L45 and L45–L5S1, but not between L23–L34. Fat infiltration in the muscle between the normal group and patients with HNP was different in the layers and the difference was greatest in the L5–S1 layer. [Conclusion] We performed correlation analysis of BMI and the total fat infiltration rate in each group to find the relationship between obesity and fat infiltration in the lumbar spine. Fat infiltration increased, and normal people or patients with chronic back pain are considered to be exposed to other diseases as fat infiltration in the lumbar spine increases. PMID:24567672

  5. New sources for Kerr and other metrics: rotating relativistic discs with pressure support

    Microsoft Academic Search

    C. Pichon; D. Lynden-Bell

    1996-01-01

    Complete sequences of new analytic solutions of Einstein's equations which describe thin supermassive discs are constructed. These solutions are derived geometrically. The identification of points across two symmetrical cuts through a vacuum solution of Einstein's equations defines the gradient discontinuity from which the properties of the disc can be deduced. The subset of possible cuts which lead to physical solutions

  6. Microstructure affects the rate of chemical, physical and color changes during storage of dried apple discs

    Microsoft Academic Search

    Nuria C. Acevedo; Vilbett Briones; Pilar Buera; José M. Aguilera

    2008-01-01

    Blanching, freezing and drying induce major changes in the physical properties of processed foods. Microstructural changes induced by these processes in apple discs were related to the degree and kinetics of browning and to fracture mechanics after drying and later storage at 70°C under a wide range of relative humidity (RH). Blanched and unblanched apple discs were dehydrated by vacuum

  7. Effectiveness and cost-effectiveness of rehabilitation after lumbar disc surgery (REALISE): design of a randomised controlled trial

    PubMed Central

    2013-01-01

    Background Patients who undergo lumbar disc surgery for herniated discs, are advocated two different postoperative management strategies: a watchful waiting policy, or referral for rehabilitation immediately after discharge from the hospital. A direct comparison of the effectiveness and cost-effectiveness of these two strategies is lacking. Methods/Design A randomised controlled trial will be conducted with an economic evaluation alongside to assess the (cost-) effectiveness of rehabilitation after lumbar disc surgery. Two hundred patients aged 18–70 years with a clear indication for lumbar disc surgery of a single level herniated disc will be recruited and randomly assigned to either a watchful waiting policy for first six weeks or exercise therapy starting immediately after discharge from the hospital. Exercise therapy will focus on resumption of activities of daily living and return to work. Therapists will tailor the intervention to the individual patient’s needs. All patients will be followed up by the neurosurgeon six weeks postoperatively. Main outcome measures are: functional status, pain intensity and global perceived recovery. Questionnaires will be completed preoperatively and at 3, 6, 9, 12 and 26 weeks after surgery. Data will be analysed according to the intention-to-treat principle, using a linear mixed model for continuous outcomes and a generalised mixed model for dichotomous outcomes. The economic evaluation will be performed from a societal perspective. Discussion The results of this trial may lead to a more consistent postoperative strategy for patients who will undergo lumbar disc surgery. Trial registration Netherlands Trial Register: NTR3156 PMID:23560810

  8. Prevalence of Disc Degeneration in Asymptomatic Korean Subjects. Part 1 : Lumbar Spine

    PubMed Central

    Lee, Tae Hoon; Lim, Soo Mee

    2013-01-01

    Objective Asymptomatic patients show high degeneration prevalence at lumbar disc in previous literatures. Unfortunately, there are few Korean data, so the authors attempted to analyze the prevalence of disc degeneration in highly selective asymptomatic Korean subjects using MRI. Methods We performed 3 T MRI sagittal scans from T12 to S1 on 102 asymptomatic subjects (50 men and 52 women) who visited our hospital between the ages of 14 and 82 years (mean age 46.3 years). All images were read independently by three observers (two neurosurgeons and one neuroradiologist) who were not given any information about the subjects. We classified grading for lumbar disc herniation (HN), annular fissure (AF), and nucleus degeneration (ND), using disc degeneration classification. Results The prevalence of HN, AF, and ND were 81.4%, 76.1%, and 75.8% respectively. Almost all levels showed an age-related proportional tendency with some exceptions. Conclusion In asymptomatic Korean subjects, the abnormal findings showed high prevalence of AF, ND, and extrusion. Especially in young ages, the authors found that bulging, protrusion, and AF showed high prevalence at L4/5 and L5/S1. And ND showed high prevalence at L5/S1. So, all lumbar disc degenerations are not pathologic, especially in children and adolescents. PMID:23440899

  9. Multipoint determination of pressure-volume curves in human intervertebral discs.

    PubMed Central

    Ranu, H S

    1993-01-01

    To gain further insight into the biomechanics of the human intervertebral disc and to determine a potential mechanism for causation and relief of symptoms related to a herniated disc, the pressure-volume relation was determined within the nucleus pulposus. Pressure was measured continuously within the nucleus pulposus in 17 intact lumbar discs from human cadavers by means of a miniature strain gauge at the tip of a size 4 French (1.3 mm) catheter inserted into the nucleus pulposus. The volume of the nucleus pulposus was increased at the slow, continuous rate of 0.034 ml/min by the pump regulated infusion of saline coloured with methylene blue. In 12 unloaded discs, nucleus pulposus pressure rose in a linear fashion (linear r = 0.96) from an initial mean pressure of 174 (SD 81) kPa. The mean rate of pressure rise was 327 (SD 109) kPa/ml volume increase. The peak pressure measured was 550 kPa; this was slightly higher than the capability of the transducer. Similar linear relations were obtained during infusion of saline into five vertically loaded discs fixed at the deformation produced by a 9.1 kg weight. The data define the pressure-volume relation within the disc and show that the nucleus pulposus, surrounded by the relatively inelastic annulus and the solid vertebral end plates, has the properties of a tight hydraulic space in which a large pressure rise will regularly result from a small increase in volume. Presumably the opposite is also true. The data may provide a biomechanical basis for the physiological variation in symptoms related to the disc, and for any benefits obtained from interventions designed to remove disc tissue. PMID:8447694

  10. Mechanical concepts for disc regeneration

    Microsoft Academic Search

    Klaus John Schnake; Michael Putzier; Norbert P. Haas; Frank Kandziora

    2006-01-01

    Different strategies exist to treat intervertebral disc degeneration. Biological attempts to regenerate the disc are promising.\\u000a However, degeneration of the disc is always accompanied by alterations of disc height, intradiscal pressure, load distribution,\\u000a and motion patterns, respectively. Since those preconditions are independent factors for disc degeneration, it is unlikely\\u000a that regeneration may occur without firstly restoring the physiological status of

  11. Bryan total disc arthroplasty: a replacement disc for cervical disc disease

    PubMed Central

    Wenger, Markus; Markwalder, Thomas-Marc

    2010-01-01

    Total disc arthroplasty is a new option in the treatment of cervical degenerative disc disease. Several types of cervical disc prostheses currently challenge the gold-standard discectomy and fusion procedures. This review describes the Bryan Cervical Disc System and presents the Bryan prosthesis, its indications, surgical technique, complications, and outcomes, as given in the literature. PMID:22915917

  12. Blunt Force Thoracic Trauma: A Case Study of Pericardial Rupture and Associated Cardiac Herniation

    PubMed Central

    Glotzer, O. S.; Bhakta, A.; Fabian, T.

    2014-01-01

    Pericardial rupture, with associated cardiac herniation, is generally fatal. Diagnosis is difficult and frequently missed due to the subtlety of identifying characteristics. We report a case of a left sided pericardial rupture and cardiac herniation resulting from a high speed motorcycle collision. This report describes the course of treatment from the emergent admission to the diagnosis of the pericardial tear to retrospective CT analysis and rupture identification. In addition the difficulties of initial diagnosis, key symptoms, and identification of CT images are presented and discussed. PMID:25184070

  13. Magnetic resonance imaging on disc degeneration changes after implantation of an interspinous spacer and fusion of the adjacent segment

    PubMed Central

    Liu, Xiaokang; Liu, Yingjie; Lian, Xiaofeng; Xu, Jianguang

    2015-01-01

    The aim of the study was to investigate the changes of the lumbar intervertebral disc degeneration by magnetic resonance imaging (MRI) after the implantation of interspinous device and the fusion of the adjacent segment. A total of 62 consecutive patients suffering L5/S1 lumbar disc herniation (LDH) with concomitant disc space narrowing or low-grade instability up to 5 mm translational slip in L5/S1 level were treated with lumbar interbody fusion (LIF) via posterior approach. Thirty-four of these patients (Coflex group) received an additional implantation of the interspinous spacer device (Coflex™) in the level L4/L5, while the rest of 28 patients (fusion group) underwent the fusion surgery alone. Clinical and radiographic examinations were performed at pre- and postoperative visits to compare the clinical outcomes and the changes of the L4/L5 vertebral disc degeneration on MRI in both Coflex and fusion group. Although both Coflex and fusion group showed improvements of the clinical outcomes assessed by the Oswestry Disability Index (ODI) after surgery, patients in Coflex group had more significant amelioration (P < 0.05) compared to fusion group. During follow up, the postoperative disc degeneration changes in Coflex group assessed by the relative signal intensity (RSI) differed from those in fusion group (P < 0.05). The supplemental implantation of Coflex™ after the fusion surgery could delay the disc degeneration of the adjacent segment.

  14. Vacuum Technology

    SciTech Connect

    Biltoft, P J

    2004-10-15

    The environmental condition called vacuum is created any time the pressure of a gas is reduced compared to atmospheric pressure. On earth we typically create a vacuum by connecting a pump capable of moving gas to a relatively leak free vessel. Through operation of the gas pump the number of gas molecules per unit volume is decreased within the vessel. As soon as one creates a vacuum natural forces (in this case entropy) work to restore equilibrium pressure; the practical effect of this is that gas molecules attempt to enter the evacuated space by any means possible. It is useful to think of vacuum in terms of a gas at a pressure below atmospheric pressure. In even the best vacuum vessels ever created there are approximately 3,500,000 molecules of gas per cubic meter of volume remaining inside the vessel. The lowest pressure environment known is in interstellar space where there are approximately four molecules of gas per cubic meter. Researchers are currently developing vacuum technology components (pumps, gauges, valves, etc.) using micro electro mechanical systems (MEMS) technology. Miniature vacuum components and systems will open the possibility for significant savings in energy cost and will open the doors to advances in electronics, manufacturing and semiconductor fabrication. In conclusion, an understanding of the basic principles of vacuum technology as presented in this summary is essential for the successful execution of all projects that involve vacuum technology. Using the principles described above, a practitioner of vacuum technology can design a vacuum system that will achieve the project requirements.

  15. Posterolateral microdisectomy for cervical monoradiculopathy caused by posterolateral soft cervical disc sequestration.

    PubMed

    Aldrich, F

    1990-03-01

    The controversy over whether to use a posterior or anterior approach for surgical treatment of soft cervical discs is still largely unsettled. However, although the posterior approach may be underutilized, it has distinct advantages when there are specific indications. Out of a large pool of cases, 53 patients presented with acute monoradiculopathy caused by soft cervical disc herniation. In 36 of these, the disc was sequestered (nonconfined) and was posterolateral to the disc space as seen on computerized tomography-myelography. Distinct motor weakness was a common clinical finding in all 36 cases. These patients were treated by using a 2- to 3-cm skin incision for the posterolateral microsurgical approach. The extent of the lateral facetectomy depended upon the relationship between the nerve root and the disc. All fragments were lateral to the dural sac and were sequestered through the anulus fibrosus and the posterior longitudinal ligament. Sequestrations were removed under direct microscopic vision, but the disc space was not entered. Pain relief and motor-power improvement in the affected radicular distribution were immediate in all patients. Sensory deficit and residual motor loss improved dramatically with normalization at approximately 6 months. No complications occurred and the mean hospital stay was 2 days. The follow-up period varied from 4 to 42 months with a mean of 26 months. Thus far, there have been no recurrences or other associated complications. By using strict selection criteria and a microsurgical posterolateral approach with removal of the sequestered disc fragment, excellent results with normalization of the monoradiculopathy can be obtained. The ease of this technique, low risk, minimal complications, and excellent results make it an attractive alternative to the anterior approach. The clinical presentations, specific indications, surgical technique, and clinical results are discussed; and a prototype of a small cervical self-retaining retractor is described. PMID:2303870

  16. One decade follow up after nucleoplasty in the management of degenerative disc disease causing low back pain and radiculopathy

    PubMed Central

    Cincu, Rafael; Lorente, Francisco de Asis; Gomez, Joaquin; Eiras, Jose; Agrawal, Amit

    2015-01-01

    Objectives: Nucleoplasty is a minimally invasive procedure that is developed to treat patients with symptomatic, but contained disc herniations or bulging discs. The purpose of this study was to evaluate a decade follow-up of coblation nucleoplasty treatment for protruded lumbar intervertebral disc. Methods: In this retrospective study there a total 50 patients who underwent intradiscal coblation therapy for symptomatic, but contained lumbar degenerative disc disease were included. Relief of low back pain, leg pain and numbness after the operation were assessed by visual analog pain scale (VAS). Function of lower limb and daily living of patients were evaluated by the Oswestry disability index (ODI) and subjective global rating of overall satisfaction were recorded and analyzed. Results: There were 27 male and 23 female with followup mean follow up of 115 months (range 105–130 months) with a mean age was 52 years (range 26–74 years). Analgesic consumption was reduced or stopped in 90% of these cases after 1 year. At 24 months follow up VAS was four points and ODI was 7.2. In three patients, we repeated the cool ablation after 36 months, at L3–4 level in two cases. Ten patients continue to be asymptomatic after 114 months of intervention. There were no complications with the procedure including nerve root injury, discitis or allergic reactions. Conclusions: Nucleoplasty may provide intermittent relief in contained disc herniation without significant complications and minimal morbidity. In accordance with the literature the evidence for intradiscal coablation therapy is moderate in managing chronic discogenic low back pain; nucleoplasty appears to be safe and effective. PMID:25767571

  17. Vacuum mechatronics

    NASA Technical Reports Server (NTRS)

    Hackwood, Susan; Belinski, Steven E.; Beni, Gerardo

    1989-01-01

    The discipline of vacuum mechatronics is defined as the design and development of vacuum-compatible computer-controlled mechanisms for manipulating, sensing and testing in a vacuum environment. The importance of vacuum mechatronics is growing with an increased application of vacuum in space studies and in manufacturing for material processing, medicine, microelectronics, emission studies, lyophylisation, freeze drying and packaging. The quickly developing field of vacuum mechatronics will also be the driving force for the realization of an advanced era of totally enclosed clean manufacturing cells. High technology manufacturing has increasingly demanding requirements for precision manipulation, in situ process monitoring and contamination-free environments. To remove the contamination problems associated with human workers, the tendency in many manufacturing processes is to move towards total automation. This will become a requirement in the near future for e.g., microelectronics manufacturing. Automation in ultra-clean manufacturing environments is evolving into the concept of self-contained and fully enclosed manufacturing. A Self Contained Automated Robotic Factory (SCARF) is being developed as a flexible research facility for totally enclosed manufacturing. The construction and successful operation of a SCARF will provide a novel, flexible, self-contained, clean, vacuum manufacturing environment. SCARF also requires very high reliability and intelligent control. The trends in vacuum mechatronics and some of the key research issues are reviewed.

  18. Resolved DEBRIS Discs

    NASA Astrophysics Data System (ADS)

    Booth, Mark; DEBRIS Team

    2011-09-01

    The Herschel DEBRIS survey is a volume-limited survey of 446 of the closest stars at wavelengths of 100 and 160 microns. Excesses at these wavelengths imply the presence of debris discs. Many of these discs were previously imaged with Spitzer but the superior angular resolution of Herschel has allowed us to resolve more than 20 of the largest of these discs. Although similar to the Kuiper belt in our own Solar System, these discs are much more massive and extend much further from their host stars. I will present images for a selection of these systems and discuss what extra information the resolved data can provide about these systems. For instance, the radii measured from the resolved images are shown to be different from that predicted by a black-body fit to the SEDs. This information allows us to infer properties about the size and composition of the dust. Resolved images can also tell us about the planetary system as a whole as the inner edges of these discs are likely to be the result of sculpting by planets. This research is funded through a Space Science Enhancement Program grant from the Canadian Space Agency.

  19. Inguinal Herniation of the Urinary Bladder Presenting as Recurrent Urinary Retention

    PubMed Central

    Frenkel, Amit; Roy-Shapira, Aviel; Shelef, Ilan; Shaked, Gadi; Koyfman, Leonid; Borer, Abraham; Klein, Moti

    2015-01-01

    Herniation of the urinary bladder into the inguinal canal is an uncommon finding, observed in 0.5–4% of inguinal hernias (Curry (2000)). It is usually associated with other conditions that increase intra-abdominal pressure such as bladder neck obstruction due to prostatic hypertrophy. Consequently, in men, it is usually associated with some degree of urinary retention. We present a 42-year-old man in whom herniation of the urinary bladder was the cause of urinary retention, and not vice versa. The patient was on tumor necrosis factor alpha antagonist (TNFA) (Etanercept) for severe Ankylosing spondylitis. Initially, the urinary retention was thought to be a side effect of the medication, but after the drug was discontinued, urinary retention persisted. CT and MRI demonstrated huge herniation of the urinary bladder into the inguinal canal. Immediately after the hernia was repaired, bladder function was restored. TNF treatment was restarted, and no further urinary symptoms were observed in the next two years of follow-up. In this case, the primary illness and its treatment were distracting barriers to early diagnosis and treatment. In younger patients with a large hernia who develop unexpected urinary retention, herniation of the urinary bladder should be highly considered in the differential diagnosis. PMID:26075132

  20. Inguinal Herniation of the Urinary Bladder Presenting as Recurrent Urinary Retention.

    PubMed

    Frenkel, Amit; Roy-Shapira, Aviel; Shelef, Ilan; Shaked, Gadi; Brotfain, Evgeni; Koyfman, Leonid; Borer, Abraham; Klein, Moti

    2015-01-01

    Herniation of the urinary bladder into the inguinal canal is an uncommon finding, observed in 0.5-4% of inguinal hernias (Curry (2000)). It is usually associated with other conditions that increase intra-abdominal pressure such as bladder neck obstruction due to prostatic hypertrophy. Consequently, in men, it is usually associated with some degree of urinary retention. We present a 42-year-old man in whom herniation of the urinary bladder was the cause of urinary retention, and not vice versa. The patient was on tumor necrosis factor alpha antagonist (TNFA) (Etanercept) for severe Ankylosing spondylitis. Initially, the urinary retention was thought to be a side effect of the medication, but after the drug was discontinued, urinary retention persisted. CT and MRI demonstrated huge herniation of the urinary bladder into the inguinal canal. Immediately after the hernia was repaired, bladder function was restored. TNF treatment was restarted, and no further urinary symptoms were observed in the next two years of follow-up. In this case, the primary illness and its treatment were distracting barriers to early diagnosis and treatment. In younger patients with a large hernia who develop unexpected urinary retention, herniation of the urinary bladder should be highly considered in the differential diagnosis. PMID:26075132

  1. Intermittent midline suprasternal neck mass caused by superior herniation of the thymus.

    PubMed

    Su, Siew Choo; Hess, Thomas; Whybourne, Annie; Chang, Anne B

    2015-03-01

    Neck masses in infants and children have a wide differential diagnosis. However, neck masses apparent only during raised intrathoracic pressure are rare with a limited number of causes, including superior herniation of the normal thymus, apical lung herniation, jugular phlebectasia and laryngocoele. These conditions can easily be differentiated from one another by imaging. We present an infant with intermittent suprasternal neck mass visible only during increased intrathoracic pressure, produced either by crying or straining. Diagnosis of superior herniation of the thymus into the neck was confirmed by ultrasonography with the characteristic sonographic appearances of the normal thymus as well as its shape, size and location. Ultrasonography should be the first imaging modality of choice. Management of superior herniation of the thymus into the neck should be conservative as the thymus naturally involutes with increasing age. Awareness of the differential diagnosis of neck swelling present only on Vasalva manoeuvre or increased intrathoracic pressure is important to prevent unnecessary tests, avoid radiation, biopsy and surgery. PMID:25266888

  2. Abnormal anatomy of inferior orbital fissure and herniation of buccal fat pad.

    PubMed

    Aldridge, T; Thomson, A; Ilankovan, V

    2015-01-01

    The anatomy of the inferior orbital fissure has been well studied, and its reported dimensions vary little. It is encountered during exploration of the orbital floor and when possible is not disturbed. We describe a case of herniation of buccal fat through the inferior orbital fissure that was found during exploration and repair of the orbital floor. PMID:25451070

  3. Stemming the Degeneration: IVD Stem Cells and Stem Cell Regenerative Therapy for Degenerative Disc Disease.

    PubMed

    Sivakamasundari, V; Lufkin, Thomas

    2013-01-01

    The intervertebral disc (IVD) is immensely important for the integrity of vertebral column function. The highly specialized IVD functions to confer flexibility and tensile strength to the spine and endures various types of biomechanical force. Degenerative disc disease (DDD) is a prevalent musculoskeletal disorder and is the major cause of low back pain and includes the more severe degenerative lumbar scoliosis, disc herniation and spinal stenosis. DDD is a multifactorial disorder whereby an imbalance of anabolic and catabolic factors, or alterations to cellular composition, or biophysical stimuli and genetic background can all play a role in its genesis. However, our comprehension of IVD formation and theetiology of disc degeneration (DD) are far from being complete, hampering efforts to formulate appropriate therapies to tackle DD. Knowledge of the stem cells and various techniques to manipulate and direct them to particular fates have been promising in adopting a stem-cell based regenerative approach to DD. Moreover, new evidence on the residence of stem/progenitor cells within particular IVD niches has emerged holding promise for future therapeutic applications. Existing issues pertaining to current therapeutic approaches are also covered in this review. PMID:23951558

  4. Microsurgical anterior decompression and internal fixation with iliac bone graft and titanium plates for treatment of cervical intervertebral disc herniation

    Microsoft Academic Search

    M. Miihlbauer; W. Saringer; M. Aichholzer; M. Sunder-Plassmann

    1995-01-01

    Summary 42 cervical interbody fusions with iliac bone graft and titanium plate fixation were performed between October 1991 and March 1994. The mean follow up period in this study was 10.7 months. In 32 cases fusion was done for 1 and in 10 cases for 2 segments. 2 different types of plates were used. In 25 cases micro-osteosynthesis plates and

  5. Electrostatic rotation of glass disc

    Microsoft Academic Search

    Roland Moser; Toshiro Higuchi

    2002-01-01

    This paper reports the successful electrostatic rotation of a glass disc of 65mm diameter. The realized electrostatic glass disc drive features high compactness and simplicity. The goal of the presented experimental work is to verify that the concept of the electrostatic glass motor can be applied to data storage devices, especially for disc drives with diameters <1in. The basic principle

  6. Revival of the Jumping Disc

    ERIC Educational Resources Information Center

    Ucke, C.; Schlichting, H-J.

    2009-01-01

    Snap discs made of bimetal have many technical applications as thermostats. Jumping discs are a toy version of such snap discs. Besides giving technical information, we describe physical investigations. We show especially how, through simple measurements and calculations, you can determine the initial speed ([approximately equal to]3.5 m…

  7. The DISC Quotient

    NASA Astrophysics Data System (ADS)

    Elliott, John R.; Baxter, Stephen

    2012-09-01

    D.I.S.C: Decipherment Impact of a Signal's Content. The authors present a numerical method to characterise the significance of the receipt of a complex and potentially decipherable signal from extraterrestrial intelligence (ETI). The purpose of the scale is to facilitate the public communication of work on any such claimed signal, as such work proceeds, and to assist in its discussion and interpretation. Building on a "position" paper rationale, this paper looks at the DISC quotient proposed and develops the algorithmic steps and comprising measures that form this post detection strategy for information dissemination, based on prior work on message detection, decipherment. As argued, we require a robust and incremental strategy, to disseminate timely, accurate and meaningful information, to the scientific community and the general public, in the event we receive an "alien" signal that displays decipherable information. This post-detection strategy is to serve as a stepwise algorithm for a logical approach to information extraction and a vehicle for sequential information dissemination, to manage societal impact. The "DISC Quotient", which is based on signal analysis processing stages, includes factors based on the signal's data quantity, structure, affinity to known human languages, and likely decipherment times. Comparisons with human and other phenomena are included as a guide to assessing likely societal impact. It is submitted that the development, refinement and implementation of DISC as an integral strategy, during the complex processes involved in post detection and decipherment, is essential if we wish to minimize disruption and optimize dissemination.

  8. Stationary Population III accretion discs

    E-print Network

    Michael Mayer; Wolfgang J. Duschl

    2004-09-02

    We present stationary models of protostellar population III (Pop III, for short) accretion discs, compare them to Pop I discs, and investigate the influence of the different chemical compositions on the occurence of gravitational, thermal and thermal-viscous instabilities in the discs. In particular in the cooler regions, we find major differences between Pop III and Pop I discs, both in the structure and stability behaviour. This is mainly due to the absence of most molecules and dust in Pop III, which are very efficient absorbers in Pop I discs.

  9. Warp propagation in astrophysical discs

    E-print Network

    Nixon, Chris

    2015-01-01

    Astrophysical discs are often warped, that is, their orbital planes change with radius. This occurs whenever there is a non-axisymmetric force acting on the disc, for example the Lense-Thirring precession induced by a misaligned spinning black hole, or the gravitational pull of a misaligned companion. Such misalignments appear to be generic in astrophysics. The wide range of systems that can harbour warped discs - protostars, X-ray binaries, tidal disruption events, quasars and others - allows for a rich variety in the disc's response. Here we review the basic physics of warped discs and its implications.

  10. Mechanotransduction in intervertebral discs

    PubMed Central

    Tsai, Tsung-Ting; Cheng, Chao-Min; Chen, Chien-Fu; Lai, Po-Liang

    2014-01-01

    Mechanotransduction plays a critical role in intracellular functioning—it allows cells to translate external physical forces into internal biochemical activities, thereby affecting processes ranging from proliferation and apoptosis to gene expression and protein synthesis in a complex web of interactions and reactions. Accordingly, aberrant mechanotransduction can either lead to, or be a result of, a variety of diseases or degenerative states. In this review, we provide an overview of mechanotransduction in the context of intervertebral discs, with a focus on the latest methods of investigating mechanotransduction and the most recent findings regarding the means and effects of mechanotransduction in healthy and degenerative discs. We also provide some discussion of potential directions for future research and treatments. PMID:25267492

  11. Biomechanics of Disc Degeneration

    PubMed Central

    Palepu, V.; Kodigudla, M.; Goel, V. K.

    2012-01-01

    Disc degeneration and associated disorders are among the most debated topics in the orthopedic literature over the past few decades. These may be attributed to interrelated mechanical, biochemical, and environmental factors. The treatment options vary from conservative approaches to surgery, depending on the severity of degeneration and response to conservative therapies. Spinal fusion is considered to be the “gold standard” in surgical methods till date. However, the association of adjacent level degeneration has led to the evolution of motion preservation technologies like spinal arthroplasty and posterior dynamic stabilization systems. These new technologies are aimed to address pain and preserve motion while maintaining a proper load sharing among various spinal elements. This paper provides an elaborative biomechanical review of the technologies aimed to address the disc degeneration and reiterates the point that biomechanical efficacy followed by long-term clinical success will allow these nonfusion technologies as alternatives to fusion, at least in certain patient population. PMID:22745914

  12. Counter-rotating accretion discs

    NASA Astrophysics Data System (ADS)

    Dyda, S.; Lovelace, R. V. E.; Ustyugova, G. V.; Romanova, M. M.; Koldoba, A. V.

    2015-01-01

    Counter-rotating discs can arise from the accretion of a counter-rotating gas cloud on to the surface of an existing corotating disc or from the counter-rotating gas moving radially inwards to the outer edge of an existing disc. At the interface, the two components mix to produce gas or plasma with zero net angular momentum which tends to free-fall towards the disc centre. We discuss high-resolution axisymmetric hydrodynamic simulations of viscous counter-rotating discs for the cases where the two components are vertically separated and radially separated. The viscosity is described by an isotropic ?-viscosity including all terms in the viscous stress tensor. For the vertically separated components, a shear layer forms between them and the middle part of this layer free-falls to the disc centre. The accretion rates are increased by factors of ˜102-104 over that for a conventional disc rotating in one direction with the same viscosity. The vertical width of the shear layer and the accretion rate are strongly dependent on the viscosity and the mass fraction of the counter-rotating gas. In the case of radially separated components where the inner disc corotates and the outer disc rotates in the opposite direction, a gap between the two components opens and closes quasi-periodically. The accretion rates are ?25 times larger than those for a disc rotating in one direction with the same viscosity.

  13. Perforation of the Pregnant Uterus during Laparoscopy for Suspected Internal Herniation after Gastric Bypass

    PubMed Central

    Harsem, N. K.; Røstad, S.; Mathisen, L. C.; Jacobsen, A. F.

    2014-01-01

    We report perforations of a pregnant uterus during laparoscopy for suspected internal herniation after gastric bypass at 24 weeks of gestation. Abdominal access and gas insufflation were achieved by the use of a 12 mm optic trocar. An additional 5 mm trocar was positioned. The perforations were handled by suturing following laparotomy and mobilisation of the high located uterus. The uterine fundus was located in the subcostal area. Internal herniation was not verified. A cesarean section was made 6 weeks later due to acute low abdominal pain. During delivery the uterus was found normal. At 5 months of age the child has developed normal and seems healthy. Optical trocars should be used with caution for abdominal access during laparoscopy in pregnancy. Open access should probably be preferred in most cases. Accidental perforations of the uterine cavity may be handled in selected cases with simple closure even following the use of large trocars under close postoperative surveillance throughout the pregnancy. PMID:25548693

  14. Third ventricle herniation into the sphenoid sinus following endoscopic transnasal transsphenoidal fenestration of Rathkes cleft cyst.

    PubMed

    Jalessi, Maryam; Sharifi, Guive; Jahanbakhshi, Amin; Parsa, Khosro; Yazdanifard, Parin

    2014-01-01

    Rathke cleft cyst (RCC) is an uncommon albeit benign sellar lesion with an incidence rate of between 2 to 33%. RCCs are usually asymptomatic except in the large cases whit suprasellar extension. We herein describe a unique case of RCC, which presented with severe visual loss owing to massive herniation of the optic chiasm and third ventricle down into the sphenoid sinus through a small 8 x 8 mm foramen after transnasal endoscopic surgical fenestration and marsupialization of the cyst. We describe a reconstruction method via endonasal transsphenoidal approach in this case and suggest prophylactic reconstruction of the sellar floor in sellar lesions with equal or more voluminous suprasellar extensions that are susceptible to such massive herniation and secondary empty sella syndrome. PMID:24535793

  15. Unilateral inferior temporal lobectomy with hippocampectomy for relief of incisural herniation

    Microsoft Academic Search

    W. B. Scoville; D. B. Bettis

    1979-01-01

    Summary 1.The syndrome of incisural hippocampal herniation, accompanied by unilateral and then bilateral fixed pupils, deepening coma, respiratory irregularity (Cheyne-Stokes), contralateral hemiplegia, ipsilateral decerebrate posturing, rising blood pressure, and finally renal shutdown, indicates a terminal state that requires immediate relief.2.Accepted methods of relief by brain shrinkage, dexamethasone, subtemporal decompression, anterior temporal lobectomy, cutting of the tentorium, and even massive uncapping

  16. Dural herniations, encephaloceles: An index of neglected chronic otitis media and further complications

    Microsoft Academic Search

    Spiros Manolidis

    2002-01-01

    A retrospective review of 110 consecutive cases of chronic otitis media surgery was carried out in a large metropolitan public teaching hospital in the United States that serves the inner-city population. The purpose was to identify dural herniations and encephaloceles (DHE) as well as complications associated with these entities. Twenty-nine such patients (26.4%) were identified, 7 of which (6.4%) were

  17. Incidence and clinical relevance of herniation of the mylohyoid muscle with penetration of the sublingual gland.

    PubMed

    Kiesler, K; Gugatschka, M; Friedrich, G

    2007-09-01

    Swelling of the submandibular region may cause problems in daily clinical diagnosis and requires further exploration. Ultrasonic examination provides a simple, non-invasive and radiation-free method. The goal of our study was to show the high incidence of herniation of the mylohyoid muscle with penetration of the sublingual glands, in some cases clinically imposing as permanent swelling. Penetration was classified into four grades (Grade 0-III). In course of routine examinations of the neck by ultrasound, the anterior part of the mylohyoid muscle was observed in 124 consecutive patients from our outpatient's clinic, presenting with unclear swelling of the neck, mostly due to lymph nodes. In resting position and during swallowing the degree of penetration of the sublingual gland through the mylohyoid muscle was staged. Almost 60% of patients showed an affection of the mylohyoid muscle at either site of varying degrees. In 40% only a thinning of the muscle could be noticed (grade I), whereas in 21 patients (17%) a significant herniation of the gland during swallowing could be observed (grade II). In two patients (2%) a constant breach of the mylohyoid muscle with permanent herniation of the gland imposing as swelling could be seen (grade III). Occasional or permanent penetration of the sublingual gland through the mylohyoid muscle is not a rare finding and can be found in almost every fifth individual using ultrasound. This may impose clinically as permanent swelling and may be of value in the differential diagnosis of swelling in the submandibular region. PMID:17479273

  18. Intraoperative atelectasis due to endotracheal tube cuff herniation: a case report.

    PubMed

    Moazeni Bitgani, Mohammad; Madineh, Hossein

    2012-01-01

    Endotracheal tube (ETT) cuff herniation is a rare, and often difficult to diagnose, cause of bronchial obstruction. We present a case of outside cuff herniation of an endotracheal tube that caused pulmonary right lung atelectasis. A 29-year-old man ,a case of car accident with multiple fractures, was admitted to the emergency ward and transferred to the operating room(OR) for open reduction and internal fixation (ORIF) of all fractures .The procedures were done under general anesthesia (G/A). The past medical history of the patient did not indicate any problem. Anesthesia was induced with thiopental, atracurium and then maintained by propofol and remifentanyl infusions and 100% O2 via orally inserted ETT. The patient was positioned in left lateral decubitus position for operation. Two hours after induction of anesthesia, the oxygen saturation level dropped to 85 % and the breath sounds in the right side of the chest were weakened. The chest x-ray images showed right lung atelectasis especially in the upper lobe. The problem was disappeared after removal of the ETT. In this case, we observed that an ETT cuff herniation can be a cause of airway obstruction. If there is a decreased unilateral breath sounds, we recommend replacement or repositioning of ETT. PMID:23165818

  19. Enclosed rotary disc air pulser

    DOEpatents

    Olson, A. L. (Idaho Falls, ID); Batcheller, Tom A. (Idaho Falls, ID); Rindfleisch, J. A. (Arco, ID); Morgan, John M. (Arco, ID)

    1989-01-01

    An enclosed rotary disc air pulser for use with a solvent extraction pulse olumn includes a housing having inlet, exhaust and pulse leg ports, a shaft mounted in the housing and adapted for axial rotation therein, first and second disc members secured to the shaft within the housing in spaced relation to each other to define a chamber therebetween, the chamber being in communication with the pulse leg port, the first disc member located adjacent the inlet port, the second disc member being located adjacent the exhaust port, each disc member having a milled out portion, the disc members positioned on the shaft so that as the shaft rotates, the milled out portions permit alternative cyclical communication between the inlet port and the chamber and the exhaust port and the chamber.

  20. Dynamics of warped accretion discs

    NASA Astrophysics Data System (ADS)

    Tremaine, Scott; Davis, Shane W.

    2014-06-01

    Accretion discs are present around both stellar-mass black holes in X-ray binaries and supermassive black holes in active galactic nuclei. A wide variety of circumstantial evidence implies that many of these discs are warped. The standard Bardeen-Petterson model attributes the shape of the warp to the competition between Lense-Thirring torque from the central black hole and viscous angular-momentum transport within the disc. We show that this description is incomplete in many accretion discs, and that torques from the companion star (for X-ray binaries) or the self-gravity of the disc (for active galactic nuclei) can play a major role in determining the properties of the warped disc. Including these effects leads to a rich set of new phenomena. For example, (i) when a companion star is present and the warp arises from a misalignment between the companion's orbital axis and the black hole's spin axis, there is no steady-state solution of the Pringle-Ogilvie equations for a warped disc when the viscosity falls below a critical value, which typically requires a disc aspect ratio ?10-3 in X-ray binaries; (ii) in AGN accretion discs, the warp can excite short-wavelength bending waves governed by the self-gravity of the disc, which propagate inwards with growing amplitude until they are damped by the disc viscosity. We show that both phenomena can occur for plausible values of the black hole and disc parameters, and briefly discuss their observational implications.

  1. 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

  2. Twin disc gear tooth simulator

    NASA Astrophysics Data System (ADS)

    Eusepi, Martin W.; Dill, James F.

    1994-05-01

    This report describes the results of an effort to develop a disc on disc test rig for evaluating lubricant load capacity. The goal of the program has been to develop a reliable disc on disc (or Twin Disc) test rig capable of providing more reliable and lower cost evaluation of lubricant load capacity than the Ryder gear test which is currently used. Disc rigs have been evaluated for this application in the past, but have failed to provide scuffing results which are comparable to those found in gear tests. The unique feature of the rig designed and evaluated under this program is a drive system design which varies the disc to disc sliding and rolling speeds in a fixed manner to simulate the combined rolling and sliding motion found in a gear tooth contact. Other features include a drive system design which insures that the same points on each disc always contact each other as they rotate, and material selection and heating system design for operation with experimental lubricants at temperatures up to 700 deg F.

  3. Vacuum Technology: Vacuum Technology III

    NSDL National Science Digital Library

    Rack, Philip D.

    This is a link to a PDF version of lecture slides that discuss gas sources in a vacuum. The presentation explains concepts such as vapor pressure curves, thermal desorption and first and second order desorption. Keywords: Vaporization, desorption, diffusion, permeation, backstreaming

  4. Preparation of ormetoprim sulfadimethoxine medicated discs for disc diffusion assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Romet (a blend of ormetoprim and sulfadimethoxine) is a typeA medicated article for the manufacture of medicated feed in the catfish industry. Recently, the commercial manufacture of ormetoprim–sulfadimethoxine susceptibility discs was discontinued. Ormetoprim–sulfadimethoxine discs were prepared at...

  5. Sizes of protoplanetary discs after star-disc encounters

    NASA Astrophysics Data System (ADS)

    Breslau, Andreas; Steinhausen, Manuel; Vincke, Kirsten; Pfalzner, Susanne

    2014-05-01

    Most stars do not form in isolation, but as part of a star cluster or association. These young stars are initially surrounded by protoplanetary discs. In these cluster environments tidal interactions with other cluster members can alter the disc properties. Besides the disc frequency, its mass, angular momentum, and energy, the disc's size is particularly prone to being changed by a passing star. So far the change in disc size has only been investigated for a small number of very specific encounters. Several studies investigated the effect of the cluster environment on the sizes of planetary systems like our own solar system, based on a generalisation of information from this limited sample. We performed numerical simulations covering the wide parameter space typical of young star clusters, to test the validity of this approach. Here the sizes of discs after encounters are presented, based on a size definition that is comparable to the one used in observational studies. We find that, except for encounters between equal-mass stars, the usually applied estimates are insufficient. They tend to severely overestimate the remaining disc size. We show that the disc size after an encounter can be described by a relatively simple dependence on the periastron distance and the mass ratio of the encounter partners. This knowledge allows us, for example, to pin down the types of encounter possibly responsible for the structure of today's solar system. Appendix A is available in electronic form at http://www.aanda.org

  6. SPOTTED DISC AND SPHERE GRAPHS URSULA HAMENSTADT

    E-print Network

    Hamenstädt, Ursula

    SPOTTED DISC AND SPHERE GRAPHS URSULA HAMENST¨ADT Abstract. The disc graph of a handlebody H;2 URSULA HAMENST¨ADT (1) For m = 1 the disc graph of H contains quasi-isometrically embedded copies of R2

  7. Towards gravitating discs around stationary black holes

    E-print Network

    O. Semerak

    2002-04-05

    This article outlines the search for an exact general relativistic description of the exterior (vacuum) gravitational field of a rotating spheroidal black hole surrounded by a realistic axially symmetric disc of matter. The problem of multi-body stationary spacetimes is first exposed from the perspective of the relativity theory and astrophysics, listing the basic methods employed and results obtained. Then, basic formulas for stationary axisymmetric solutions are summarized. Remaining sections review what we have learnt with Miroslav Zacek and Tomas Zellerin about certain static and stationary situations recently. Although the survey part is quite general, the list of references cannot be complete. Our main desideratum was the informative value rather than originality -- novelties have been preferred, mainly reviews and those with detailed introductions.

  8. Cervical Total Disc Arthroplasty

    PubMed Central

    Basho, Rahul; Hood, Kenneth A.

    2012-01-01

    Symptomatic adjacent segment degeneration of the cervical spine remains problematic for patients and surgeons alike. Despite advances in surgical techniques and instrumentation, the solution remains elusive. Spurred by the success of total joint arthroplasty in hips and knees, surgeons and industry have turned to motion preservation devices in the cervical spine. By preserving motion at the diseased level, the hope is that adjacent segment degeneration can be prevented. Multiple cervical disc arthroplasty devices have come onto the market and completed Food and Drug Administration Investigational Device Exemption trials. Though some of the early results demonstrate equivalency of arthroplasty to fusion, compelling evidence of benefits in terms of symptomatic adjacent segment degeneration are lacking. In addition, non-industry-sponsored studies indicate that these devices are equivalent to fusion in terms of adjacent segment degeneration. Longer-term studies will eventually provide the definitive answer. PMID:24353955

  9. Herniation of the gallbladder within a hernia of the abdominal wall associated with Mirizzi Syndrome.

    PubMed

    Paolino, LA; Millan, M; Bossi, M; Champault, G; Barrat, C

    2011-01-01

    A gallbladder incarcerated hernia associated with Mirizzi syndrome is a very rare entity and to our knowledge this is the first case ever described in literature. An 85-year-old man presented at the emergency department with a tender right upper quadrant mass. Computed Tomography (CT) revealed the presence of a gallbladder lithiasis with signs of acute cholecystitis, herniated through the abdominal wall with an associated Mirizzi syndrome. Laparoscopic cholecystectomy and repair of the abdominal wall defect were performed. The patient recovered very well and the postoperative period was uneventful. PMID:24950574

  10. Herniation of the gallbladder within a hernia of the abdominal wall associated with Mirizzi Syndrome

    PubMed Central

    Paolino, LA; Millan, M; Bossi, M; Champault, G; Barrat, C

    2011-01-01

    A gallbladder incarcerated hernia associated with Mirizzi syndrome is a very rare entity and to our knowledge this is the first case ever described in literature. An 85-year-old man presented at the emergency department with a tender right upper quadrant mass. Computed Tomography (CT) revealed the presence of a gallbladder lithiasis with signs of acute cholecystitis, herniated through the abdominal wall with an associated Mirizzi syndrome. Laparoscopic cholecystectomy and repair of the abdominal wall defect were performed. The patient recovered very well and the postoperative period was uneventful. PMID:24950574

  11. Recurrent pseudoaneurysm of the left ventricle with subcutaneous herniation into the chest wall. A case report.

    PubMed Central

    Rao, M S; Vaijyanath, P; Taneja, K; Dubey, B; Manchanda, S C; Venugopal, P

    1998-01-01

    Pseudoaneurysm of the left ventricle is rare, and recurrence is extremely rare. We report the case of a 62-year-old man who presented at our hospital with a painless pulsatile swelling in the left breast. He had undergone coronary artery bypass grafting and left-ventricular aneurysmectomy 14 years earlier. On investigation, the swelling was diagnosed to be a pseudoaneurysm of the left ventricle with subcutaneous herniation. The extreme rarity of this condition prompted us to report the case. The investigative techniques and the surgical strategy are discussed. Images PMID:9885110

  12. Management of Cerebellar Tonsillar Herniation following Lumbar Puncture in Idiopathic Intracranial Hypertension

    PubMed Central

    Hoffman, Kenneth R.; Chan, Sean W.; Hughes, Andrew R.; Halcrow, Stephen J.

    2015-01-01

    Lumbar puncture is performed routinely for diagnostic and therapeutic purposes in idiopathic intracranial hypertension, despite lumbar puncture being classically contraindicated in the setting of raised intracranial pressure. We report the case of a 30-year-old female with known idiopathic intracranial hypertension who had cerebellar tonsillar herniation following therapeutic lumbar puncture. Management followed guidelines regarding treatment of traumatic intracranial hypertension, including rescue decompressive craniectomy. We hypothesize that the changes in brain compliance that are thought to occur in the setting of idiopathic intracranial hypertension are protective against further neuronal injury due to axonal stretch following decompressive craniectomy. PMID:25685562

  13. Gastric outlet obstruction secondary to paraesophageal herniation of gastric antrum after laparoscopic fundoplication.

    PubMed

    Coskun, Selcuk; Soylu, Lutfi; Sahin, Mahir; Demiray, Taylan

    2015-04-01

    The most common causes of acute gastric outlet obstruction (GOO) are duodenal and type 3 gastric ulcers. However, mechanical or functional causes may also lead to this pathology. Acute GOO is characterized by delayed gastric emptying, anorexia, or nausea accompanied by vomiting. Herein we report a 56-year-old man diagnosed with GOO secondary to paraesophageal hiatal herniation of gastric antrum after laparoscopic fundoplication. Because of the rarity of this disease, common gastrointestinal complaints may mislead the emergency physician to diagnose a nonsurgical gastrointestinal disease if a detailed history and physical examinations are not obtained. PMID:25813602

  14. Ventral Transdural Herniation of the Thoracic Spinal Cord: Surgical Treatment in Four Cases and Review of Literature

    Microsoft Academic Search

    B. Vallée; Ph. Mercier; Ph. Menei; F. Bouhour; C. Fischer; D. Fournier; R. Bougeard; S. Diabira; K. Mahla

    1999-01-01

    Summary  ?Background. A specific cause of progressive Brown-Sequard syndrome has been identified: a ventral herniation of the thoracic spinal\\u000a cord through the dural sleeve on one side.\\u000a \\u000a \\u000a Method. Four female patients who were affected by a progressive Brown Sequard syndrome related to a transdural spinal cord herniation\\u000a have been investigated and were submitted to surgery and postoperative evaluation.\\u000a \\u000a \\u000a \\u000a \\u000a Findings. The MRI

  15. Tissue engineering: A live disc

    NASA Astrophysics Data System (ADS)

    Hukins, David W. L.

    2005-12-01

    A material-cell hybrid device that mimics the anatomic shape of the intervertebral disc has been made and successfully implanted into mice to show that tissue engineering may, in the future, benefit sufferers from back pain.

  16. Optic disc shape in glaucoma

    Microsoft Academic Search

    Jost B. Jonas; Konstantinos I. Papastathopoulos

    1996-01-01

    • Background: This study was performed to evaluate the shape of the optic disc in glaucoma. • Methods: We examined morphometrically\\u000a color stereo optic disc photographs of patients with primary open-angle glaucoma (n=804), secondary open-angle glaucoma (n=130), normal-pressure glaucoma (n=75), and high myopia combined with open-angle glaucoma (n=33), visually normal subjects (n=421), and nonglaucomatous subjects with high myopia (n=36). The

  17. Idiopathic Spinal Cord Herniation: Case Report and Review of the Literature

    PubMed Central

    Sasani, Mehdi; Ozer, Ali F; Vural, Metin; Sarioglu, Ali C

    2009-01-01

    Background: Idiopathic spinal cord herniation (ISCH) is a rare cause of progressive myelopathy frequently present in Brown-Séquard syndrome. Preoperative diagnosis can be made with magnetic resonance imaging (MRI). Many surgical techniques have been applied by various authors and are usually reversible by surgical treatment. Methods: Case report and review of the literature. Findings: A 45-year-old woman with Brown-Séquard syndrome underwent thoracic MRI, which revealed transdural spinal cord herniation at T8 vertebral body level. During surgery the spinal cord was reduced and the ventral dural defect was restorated primarily and reinforced with a thin layer of subdermal fat. The dural defect was then closed with interrupted stitches. Results: Although neurologic status improved postoperatively, postsurgical MRI demonstrated swelling and abnormal T2-signal intensity in the reduced spinal cord. Review of the English language literature revealed 100 ISCH cases. Conclusions: ISCH is a rare clinical entity that should be considered in differential diagnosis of Brown-Séquard syndrome, especially among women in their fifth decade of life. Outcome for patients who initially had Brown-Séquard syndrome was significantly better than for patients who presented with spastic paralysis. Although progression of neurologic deficits can be very slow, reduction of the spinal cord and repair of the defect are crucial in stopping or reversing the deterioration. PMID:19264054

  18. Differentiation of idiopathic spinal cord herniation from CSF-isointense intraspinal extramedullary lesions displacing the cord.

    PubMed

    Haber, Marc D; Nguyen, Dustin D; Li, Shan

    2014-01-01

    Focal spinal cord displacement can be caused by idiopathic spinal cord herniation (ISCH), in which the cord protrudes through a dural defect into the epidural space, causing cord displacement and tethering. ISCH is uncommon and often is misdiagnosed initially, which results in delayed management. ISCH can be mimicked by space-occupying cerebrospinal fluid (CSF)-isointense intraspinal extramedullary lesions, such as epidermoid cysts or teratomas, intradural arachnoid cysts, epidural hematomas or abscesses, cystic nerve sheath tumors, synovial or Tarlov cysts, meningoceles, and pseudomeningoceles. Initial computed tomography (CT) and unenhanced magnetic resonance (MR) imaging studies may depict focal cord displacement and a widened CSF space but often are not sufficient to identify the underlying cause. High-resolution thin-section MR imaging can delineate the exact location of the dural defect and the protrusion of the herniated cord through this defect into the epidural space. At imaging, unimpeded CSF pulsation artifacts seen within a widened CSF space exclude a space-occupying lesion. A filling defect seen at conventional or CT myelography can help confirm a CSF-isointense space-occupying lesion; intravenous contrast agent administration can help exclude a rim-enhancing cystic extramedullary lesion. The clinical presentation usually is nonspecific, but symptom acuity, fever, and trauma can guide the imaging evaluation and help narrow the differential diagnosis. A multimodality imaging approach is essential to differentiate ISCH from space-occupying CSF-isointense intraspinal extramedullary lesions. PMID:24617681

  19. Viscoelastic Disc Arthroplasty Provides Superior Back and Leg Pain Relief in Patients with Lumbar Disc Degeneration Compared to Anterior Lumbar Interbody Fusion

    PubMed Central

    Rischke, Burkhard; Smith, Eric

    2015-01-01

    Background Lumbar disc degeneration (LDD) is one of the most frequently diagnosed spinal diseases. The symptoms these disorders cause are anticipated to increase as the population in Western countries ages. Purpose Compare back and leg pain alleviation in patients with LDD and a viscoelastic disc prosthesis documented in the SWISSspine registry versus patients with anterior lumbar interbody fusion documented in the Spine Tango registry. Study Design Prospectively collected clinical and outcome data in two independent spine registries. Outcome Measures were back and leg pain relief on 0 to 10 numerical rating scales. Materials and Methods The analysis included a single surgeon series of 48 patients with viscoelastic total disc replacement (VTDR) from the SWISSspine registry which were compared to 131 patients with anterior lumbar interbody fusion (ALIF) from the Spine Tango registry. Two linear multivariate regression models were built to assess the associations of patient characteristics with back and leg pain relief. The following covariates were included in the models: patient age and sex, disc herniation as additional diagnosis, number of treated segments, level of treated segment, treatment type (VTDR, ALIF), preoperative back and leg pain levels and follow-up interval. Results Both models showed VTDR to be associated with significantly higher back (2.76 points; 95% confidence interval (CI) 1.78 - 3.73; p < 0.001) and leg pain (2.12 points; 95% CI 1.12 to 3.13; p < 0.001) relief than ALIF. Other influential factors for higher back pain relief were female sex compared with male sex (1.03 additional points; 95% CI 0.27 to 1.78; p = 0.008), monosegmental surgery compared with bisegmental surgery (1.02 additional points; 95% CI 0.21 to 1.83; p = 0.014), and higher back pain at baseline (0.87 points additional pain relief per level of preoperative back pain; 95% CI 0.70 to 1.03; p < 0.001). Other influential factors for leg pain relief were monosegmental surgery (0.93 additional points; 95% CI 0.10 to 1.77; p = 0.029) and higher leg pain at baseline (0.83 points additional pain relief per level of preoperative leg pain; 95% CI 0.70 to 0.96). In both models the L3/4 segment showed 2.36 points (95% CI -4.27 to -0.45; p = 0.016) and 3.69 points (95% CI -5.66 to -1.71; p < 0.001) less pain relief than L5/S1. Discussion Significantly higher back and leg pain relief were observed after viscoelastic total disc replacement in comparison with anterior lumbar interbody fusion. The new less rigid materials used in the second generation total disc replacements (TDRs) may make artificial disc replacement an increasingly attractive option for patients with degenerative lumbar disc disease. Further controlled and long-term follow-up studies are required for more detailed comparisons of the outcomes of these types of disc implants. The Freedom Lumbar Disc is limited by U.S. federal law to investigational use only. PMID:26196033

  20. Posterior decompression salvages Bryan total disc arthroplasty in post-operatively recurrent uncoforaminal stenosis.

    PubMed

    Wenger, Markus; Markwalder, Thomas-Marc

    2014-05-01

    We report on 69 retrospectively reviewed patients who received 73 Bryan (Medtronic Sofamor Danek, Memphis, TN, USA) total disc arthroplasties for recent soft cervical disc herniations over a 9.3year period. Three patients returned with radiculopathy due to the redevelopment of uncoforaminal stenosis at the Bryan segment and later underwent posterior decompression of the uncoforaminal area without modification to the prosthesis. They recovered from the radiculopathy after decompression; however, one patient later required adjacent segment fusion to recover from concomitant cervicalgia. After posterior decompression, all prostheses continued to function normally. In one patient, however, bony bridging of the prosthesis is imminent, despite being currently asymptomatic. We normally exclude patients with uncoforaminal stenosis from Bryan arthroplasty. Analysis of three of these patients (4.3% of patients, 4.1% of prostheses) revealed that they received a prosthesis despite slight uncoforaminal stenosis (slight stenosis was known prior to surgery in one instance, two others were only discovered intra-operatively). Our observation raises the suspicion that slight uncoforaminal stenosis could also recur in physiologically working arthroplasty segments, and that in some instances this spur formation may progress into prosthesis bridging. However, more research is required to confirm the significance of uncoforaminal stenosis discovered pre- or intra-operatively in arthroplasty patients. Posterior minimally invasive decompression using the Frykholm-Scoville keyhole approach successfully treats uncoforaminal stenosis without revising the prosthesis. PMID:24256884

  1. Intrathoracic major duodenal papilla with transhiatal herniation of the pancreas and duodenum: A case report and review of the literature

    PubMed Central

    Jäger, Tarkan; Neureiter, Daniel; Nawara, Clemens; Dinnewitzer, Adam; Öfner, Dietmar; Lamadé, Wolfram

    2013-01-01

    Transhiatal herniation of the pancreas is an extremely rare condition. In the published literature we found only eleven cases reported in the period of 1958 to 2011. A coincidental hiatal herniation of the duodenum is described in two cases only. To our knowledge, we report the first case with a hiatal herniation of the complete duodenum and proximal pancreas presenting an intrathoracic major duodenal papilla with consecutive intrahepatic and extrahepatic cholestasis. A 72-year-old Caucasian woman was admitted to our department with a hiatal hernia grade IV for further evaluation. According to our recommendation of surgical hernia repair soon after the diagnosis of a transhiatal herniation of the proximal pancreas and entire duodenum, we had to respect the declared intention of the patient for a conservative procedure. So we were forced to wait for surgical repair within an emergency situation complicated by a myocardial infarction and reduced general condition. We discuss the therapeutic decision making process and a complete literature review of this rare entity. PMID:23805366

  2. Effect of optic disc size or age on evaluation of optic disc variables

    Microsoft Academic Search

    Changwon Kee; Hyungjin Koo; Yonghoon Ji; Seonwoo Kim

    1997-01-01

    AIMS\\/BACKGROUNDIt has been reported that the number of optic nerve fibres decrease with age, and the cup\\/disc (C\\/D) ratio increases as the optic disc size increases. Consequently, the normal value of the optic disc variables measured by an optic disc analyser may change according to the optic disc size or age. The effect of individual variations in optic disc size

  3. Epidural Fibrosis after Lumbar Disc Surgery: Prevention and Outcome Evaluation

    PubMed Central

    Abdel Razek, Naglaa M.

    2015-01-01

    Study Design This is a prospective, randomized, controlled study designed and conducted over 10 years from 2002 to 2012. Purpose The study aimed to monitor the effect of suction drains (SD) on the incidence of epidural fibrosis (EF) and to test, if the use of SD alone, SD with local steroids application, SD combined with fat grafts and local steroids application, or SD combined with fat grafts and without local steroids application, would improve outcome. Overview of Literature EF contributes to significant unsatisfactory failed-back syndrome. Efforts have been tried to reduce postoperative EF, but none were ideal. Methods Between September 2002 and 2012, 290 patients with symptomatic unilateral or bilateral, single-level lumbar disc herniation were included in the study. Two groups were included, with 165 patients in group I (intervention group) and 125 patients in group II (control group). Group I was subdivided into four subgroups: group Ia (SD alone), group Ib (SD+fat graft), group Ic (SD+local steroids), and group Id (SD+fat graft+local steroids). Results The use of SD alone or combined with only fat grafts, fats grafts and local steroids application, or only local steroids application significantly improved patient outcome and significantly reduced EF as measured by magnetic resonance imaging (MRI). Conclusions This study has clearly demonstrated the fact that the use of suction drainage alone or combined with only fat grafts, fats grafts and local steroids application, or only local steroids application significantly improved patient outcome with respect to pain relief and functional outcome and significantly reduced EF as measured by an MRI. A simple grading system of EF on MRI was described.

  4. Can intervertebral disc prolapse be predicted by disc mechanics?

    PubMed

    McNally, D S; Adams, M A; Goodship, A E

    1993-09-01

    The hypothesis was tested that stress concentrations in the posterior anulus of an intervertebral disc predispose it to prolapse under high compressive loads and anterolateral bending. The distribution of compressive stress inside the intervertebral discs of 22 cadaveric lumbar motion segments was measured with the specimens loaded in pure compression and in compression combined with anterolateral bending. Each motion segment was then loaded to failure in combined compression and anterolateral bending. Failure occurred in the vertebral body (n = 12) or posterolateral anulus (n = 10); the latter group showed a significantly greater incidence of stress concentrations (P < 0.001) in the posterior anulus, when loaded in compression and bending. It was concluded that some discs are predisposed to prolapse because of damaging, localized concentrations of stress in the posterior anulus in combined anterolateral bending and compression. PMID:8235825

  5. The Chemistry of Optical Discs

    NASA Astrophysics Data System (ADS)

    Birkett, David

    2002-09-01

    The rapid rise of optical data storage is clearly a triumph for physics, engineering, and information technology, but a great deal of chemical innovation has also been necessary to make this revolution possible. This article explores the polymer and material science that has gone into the development of CDs and DVDs in prerecorded, write-once, and erasable formats, and magneto-optical (MO) discs and the related minidiscs. Prerecorded CDs and DVDs, where the data is stored as a series of pits physically stamped into a plastic disc, have required new optically-clear grades of the base plastic, technically sophisticated UV acrylic adhesives and lacquers, and a detailed understanding of the surface energy and the optical and electrochemical properties of metals in very thin layers. The different recordable formats have all needed new chemistry for the recording layer: cyanine and phthalocyanine dyes for write-once discs, low-melting alloys with a glassy state for erasable discs, and magnetic materials with closely defined Curie temperatures and hysteresis for MO and minidiscs. Even newer optical storage formats, including multilayer fluorescent or holographic discs are under development, and these are already demanding critical inputs by chemists.

  6. Debris disc formation induced by planetary growth

    NASA Astrophysics Data System (ADS)

    Kobayashi, H.; Löhne, T.

    2014-08-01

    Several hundred stars older than 10 million years have been observed to have infrared excesses. These observations are explained by dust grains formed by the collisional fragmentation of hidden planetesimals. Such dusty planetesimal discs are known as debris discs. In a dynamically cold planetesimal disc, collisional coagulation of planetesimals produces planetary embryos which then stir the surrounding leftover planetesimals. Thus, the collisional fragmentation of planetesimals that results from planet formation forms a debris disc. We aim to determine the properties of the underlying planetesimals in debris discs by numerically modelling the coagulation and fragmentation of planetesimal populations. The brightness and temporal evolution of debris discs depend on the radial distribution of planetesimal discs, the location of their inner and outer edges, their total mass, and the size of planetesimals in the disc. We find that a radially narrow planetesimal disc is most likely to result in a debris disc that can explain the trend of observed infrared excesses of debris discsvvv around G-type stars, for which planet formation occurs only before 100 million years. Early debris disc formation is induced by planet formation, while the later evolution is explained by the collisional decay of leftover planetesimals around planets that have already formed. Planetesimal discs with underlying planetesimals of radii ˜100 km at ?30 au most readily explain the Spitzer Space Telescope 24 and 70 ?m fluxes from debris discs around G-type stars.

  7. Inhomogeneous vacuum energy

    NASA Astrophysics Data System (ADS)

    Wands, David; De-Santiago, Josue; Wang, Yuting

    2012-07-01

    Vacuum energy remains the simplest model of dark energy which could drive the accelerated expansion of the Universe without necessarily introducing any new degrees of freedom. Inhomogeneous vacuum energy is necessarily interacting in general relativity. Although the 4-velocity of vacuum energy is undefined, an interacting vacuum has an energy transfer and the vacuum energy defines a particular foliation of spacetime. In particular we will discuss cosmological solutions where the background vacuum energy is spatially homogeneous. It is possible to give a consistent description of vacuum dynamics and in particular the relativistic equations of motion for spatially inhomogeneous perturbations given a covariant prescription for the vacuum energy, or equivalently the energy transfer 4-vector, and we construct gauge-invariant vacuum perturbations. We show that any dark energy cosmology can be decomposed into an interacting vacuum+matter cosmology whose inhomogeneous perturbations obey simple first-order equations.

  8. Photon Bubbles in Accretion Discs

    E-print Network

    Charles F. Gammie

    1998-02-17

    We show that radiation dominated accretion discs are likely to suffer from a ``photon bubble'' instability similar to that described by Arons in the context of accretion onto neutron star polar caps. The instability requires a magnetic field for its existence. In an asymptotic regime appropriate to accretion discs, we find that the overstable modes obey the remarkably simple dispersion relation \\omega^2 = -i g k F(B,k). Here g is the vertical gravitational acceleration, B the magnetic field, and F is a geometric factor of order unity that depends on the relative orientation of the magnetic field and the wavevector. In the nonlinear outcome it seems likely that the instability will enhance vertical energy transport and thereby change the structure of the innermost parts of relativistic accretion discs.

  9. Herniated disk

    MedlinePLUS

    ... often starts slowly. It may get worse: After standing or sitting At night When sneezing, coughing, or ... a hard time lifting your leg or arm, standing on your toes on one side, squeezing tightly ...

  10. Germanium detector vacuum encapsulation

    NASA Technical Reports Server (NTRS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-01-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  11. Germanium detector vacuum encapsulation

    NASA Astrophysics Data System (ADS)

    Madden, N. W.; Malone, D. F.; Pehl, R. H.; Cork, C. P.; Luke, P. N.; Landis, D. A.; Pollard, M. J.

    1991-08-01

    This paper describes an encapsulation technology that should significantly improve the viability of germanium gamma-ray detectors for a number of important applications. A specialized vacuum chamber has been constructed in which the detector and the encapsulating module are processed in high vacuum. Very high vacuum conductance is achieved within the valveless encapsulating module. The detector module is then sealed without breaking the chamber vacuum. The details of the vacuum chamber, valveless module, processing, and sealing method are presented.

  12. Assessing the Effect of Spaceflight on the Propensity for Astronauts to Develop Disk Herniation

    NASA Technical Reports Server (NTRS)

    Feiveson, Alan H.; Mendez, C. M.; Somers, J. T.

    2015-01-01

    A previous study [1] reported the instantaneous risk of developing a Herniated Nucleus Pulosus (HNP) was higher in astronauts who had flown at least one mission, as compared with those in the corps who had not yet flown. However, the study only analyzed time to HNP after the first mission (if any) and did not account for the possible effects of multiple missions. While many HNP's occurred well into astronauts' careers or in some cases years after retirement, the higher incidence of HNPs relatively soon after completion of space missions appears to indicate that spaceflight may lead to an increased risk of HNP. The purpose of this study was to support the Human System Risk Boards assessment of back pain, assess the risk of injury due to dynamic loads, and update the dataset analyzed which contained data through December 31, 2006.

  13. Herniation of unruptured tuberculous lung abscess into chest wall without pleural or bronchial spillage

    PubMed Central

    Magazine, Rahul; Mohapatra, Aswini K.; Manu, Mohan K.; Srivastava, Rajendra K.

    2011-01-01

    A 22-year-old unmarried man presented to the chest outpatient department with a history of productive cough of two-month duration. He also complained of pain and swelling on the anterior aspect of right side of chest of one-month duration. Imaging studies of the thorax, including chest roentgenography and computerized tomography, revealed an unruptured lung abscess which had herniated into the chest wall. Culture of pus aspirated from the chest wall swelling grew Mycobacterium tuberculosis. He was diagnosed to have a tuberculous lung abscess which had extended into the chest wall, without spillage into the pleural cavity or the bronchial tree. Antituberculosis drugs were prescribed, and he responded to the treatment with complete resolution of the lesion. PMID:22084547

  14. Subdural haemorrhage and severe coagulopathy resulting in transtentorial uncal herniation in a neonate undergoing therapeutic hypothermia.

    PubMed

    Wang, Dianna; McMillan, Hugh; Bariciak, Erika

    2014-01-01

    Therapeutic hypothermia has been shown to be efficacious for improving long-term neurodevelopmental outcomes following perinatal asphyxia. Thus, cooling protocols have been adopted at most tertiary neonatal centres. We present a case of a term neonate who underwent therapeutic whole-body cooling for hypoxic ischaemic encephalopathy following a difficult forceps delivery. She abruptly deteriorated, exhibiting signs of transtentorial uncal herniation and severe disseminated intravascular coagulopathy. CT of the head confirmed a life-threatening subdural haematoma and a concealed skull fracture. Hypothermia has been shown to impair haemostasis in vivo and thus may potentially exacerbate occult haemorrhages in a clinical setting. Newborns that require instrument-assisted delivery are a particularly high-risk group for occult head injuries and should undergo careful clinical assessment for fractures and intracranial haemorrhage prior to initiation of therapeutic hypothermia. PMID:25100805

  15. Computer animation via optical video disc

    E-print Network

    Bender, Walter

    1981-01-01

    This paper explores the notion of marrying two technologies: raster-scan computer animation and optical video discs. Animated sequences, generated at non real-time rates, then transfered to video disc, can be recalled under ...

  16. Physics and chemistry of gas in discs 

    E-print Network

    Tilling, Ian

    2013-11-28

    Protoplanetary discs set the initial conditions for planet formation. By combining observations with detailed modelling, it is possible to constrain the physics and chemistry in such discs. I have used the detailed ...

  17. JOURNAL DE PHYSIQUE Colloque C6,supplgment au no 8, Tome 39, aozit 1978, page C6.1194 A METHOD TO MEASURE THE THERMAL CONDUCTIVITY OF DISCS OF ARBITRARY SHAPE,

    E-print Network

    Paris-Sud XI, Université de

    was mounted in a vacuum chamber inside a su- perconducting solenoid so that the magnetic field is directed TO MEASURE THE THERMAL CONDUCTIVITY OF DISCS OF ARBITRARY SHAPE, DEMONSTRATED ON A TYPE-II SUPERCONDUCTOR P of discs of arbitrary shape has been converted to the case of thermal conduction. The method has been

  18. Relatively uniform and accelerated degradation of pure iron coated with micro-patterned Au disc arrays.

    PubMed

    Cheng, J; Huang, T; Zheng, Y F

    2015-03-01

    Pure iron has been proven to be a potential biodegradable metal, but its degradation rate was too slow. To accelerate its biodegradation, micro-patterned Au disc films were deposited on the surface of pure iron by vacuum sputtering. The influence of Au disc films on the degradation of pure iron matrix in vitro was investigated in the present study. Electrochemical measurement results indicated that the corrosion current density of pure iron coated with micro-patterned Au disc films in Hank's solution was 4 times larger than that of the uncoated one, while the difference between the influences of micro-patterned Au discs with different diameters on the corrosion rate of pure iron was insignificant. Immersion test indicated that the corrosion depth for pure iron coated with Au disc films was about three times as that of bare pure iron. Both electrochemical test and immersion test revealed that the corrosion of pure iron matrix coated with Au disc array became more uniform. PMID:25579971

  19. Location of Optical Disc in Retinal Image

    Microsoft Academic Search

    D. Santhi; D. Manimegalai

    2007-01-01

    This paper proposes a method to automatically locate the optic disc in a retinal image. Our method of finding the optic disc is based on the properties of the optic disc using simple image processing algorithms which include multilevel thresholding, Morphological process detection of object roundness and circle detection by circle fitting method. The proposed method is able to recognize

  20. Locating the Optic Disc in Retinal Images

    Microsoft Academic Search

    Mira Park; Jesse S. Jin; Suhuai Luo

    2006-01-01

    We present a method to automatically outline the optic disc in a retinal image. Our method for finding the optic disc is based on the properties of the optic disc using simple image processing algorithms which include thresholding, detection of object roundness and circle detection by Hough transformation. Our method is able to recognize the retinal images with general properties

  1. Requirements and specifications for cartographic video discs

    Microsoft Academic Search

    D. J. Costanzo

    1984-01-01

    Video discs can store large quantities of analog (paper, film, and video tape) and digital cartographic products on a compact, nonvolatile medium. These discs can be interfaced with microcomputers to provide compact and portable systems for accessing this cartographic information. Such interactive video disc systems could be used for terrain analysis, navigation, map use training, and command and control. Video

  2. Optical Discs: New Storage Media for Education.

    ERIC Educational Resources Information Center

    Helgerson, Linda W.

    1987-01-01

    Discusses three new advances in the use of optical disc technology in education. Describes the storage formats and capabilities of the videodisc, the compact disc, and the optical write-once disc. Contrasts the three technologies in terms of their production requirements, the hardware involved, and some projected applications in education. (TW)

  3. Intramural Sports Ultimate Disc "Hat"

    E-print Network

    Escher, Christine

    Intramural Sports Ultimate Disc "Hat" Tournament Summer 2014 Intramural Sports Calendar of Events on the day of the tournament, teams will be drawn out of a hat and mixed for play. Sports and Special or Faculty/Staff/Affiliates with a Recreational Sports Membership are eligible to participate. http://oregonstate.edu/recsports/intramural-sports

  4. Optical Disc Applications in Libraries.

    ERIC Educational Resources Information Center

    Andre, Pamela Q. J.

    1989-01-01

    Discusses a variety of library applications of optical disc storage technology, including CD-ROM, digital videodisc, and WORM. Research and development projects at the Library of Congress, National Library of Medicine, and National Agricultural Library are described, products offered by library networks are reviewed, and activities in academic and…

  5. Electromagnetic Levitation of a Disc

    ERIC Educational Resources Information Center

    Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.

    2012-01-01

    This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…

  6. OPTIC DISC CHARACTERISTICS ASSESSED BY EVALUATION OF CLINICAL OPTIC DISC PHOTOGRAPHS IN GLAUCOMA PATIENTS

    Microsoft Academic Search

    Ikuyo Ohguro; Hiroshi Ohguro; Hiroshi Ohkuro; Mitsuru Nakazawa

    Purpose: To describe optic disc characteristics assessed by evaluation of clinical optic disc photographs and to utilize these findings to differentiate glaucoma patients and normal subjects. Patients and Methods: A total of 329 eyes of 329 glaucoma patients and 220 eyes of 220 normal subjects were included The disc diameter to disc-to-macula distance ratio (DD\\/DM ratio), cup-to-disc diameter ratio (C\\/D

  7. Evolution of linear warps in accretion discs and applications to protoplanetary discs in binaries

    NASA Astrophysics Data System (ADS)

    Foucart, Francois; Lai, Dong

    2014-12-01

    Warped accretion discs are expected in many protostellar binary systems. In this paper, we study the long-term evolution of disc warp and precession for discs with dimensionless thickness H/r larger than their viscosity parameter ?, such that bending waves can propagate and dominate the warp evolution. For small warps, these discs undergo approximately rigid-body precession. We derive analytical expressions for the warp/twist profiles of the disc and the alignment time-scale for a variety of models. Applying our results to circumbinary discs, we find that these discs align with the orbital plane of the binary on a time-scale comparable to the global precession time of the disc, and typically much smaller than its viscous time-scale. We discuss the implications of our finding for the observations of misaligned circumbinary discs (such as KH 15D) and circumbinary planetary systems (such as Kepler-413); these observed misalignments provide useful constraints on the uncertain aspects of the disc warp theory. On the other hand, we find that circumstellar discs can maintain large misalignments with respect to the plane of the binary companion over their entire lifetime. We estimate that inclination angles larger than ˜20° can be maintained for typical disc parameters. Overall, our results suggest that while highly misaligned circumstellar discs in binaries are expected to be common, such misalignments should be rare for circumbinary discs. These expectations are consistent with current observations of protoplanetary discs and exoplanets in binaries, and can be tested with future observations.

  8. The lumbar disc and low back pain.

    PubMed

    Bogduk, N

    1991-10-01

    The lumbar disc serves to sustain compression loads and is subject to tension and shear in forward bending and rotation. Its outer third is innervated and can be a source of pain. The annulus fibrosus may be injured in rotation and flexion of the lumbar spine and may become symptomatic as a ligamentous injury. Compression injuries of the disc are initially asymptomatic but may set in train a degradative process that, in time, leads to internal disc disruption, which becomes symptomatic as a result of chemical or mechanical irritation of nociceptors in the annulus fibrosus. Disc prolapse is but one possible end stage of internal disc disruption and represents the culmination of a series of destructive processes affecting the disc. This condition can be symptomatic while the external appearance of the disc remains normal and before nerve roots are affected in any way. PMID:1821758

  9. Educational Vacuum Trainers

    NSDL National Science Digital Library

    Hansen, Steve

    Have you inherited a bell jar vacuum system and are scratching your head over how to set it up or are unsure of its operations or capabilities? Or do you want to do more with your bell jar vacuum? The forum on Bell Jar Vacuums - with the topic Vacuum Trainers can help you. The intent of this forum is for this to be a place where technical issues, classroom exercises, activities, etc. can be discussed. There's no endorsement by manufacturers and commercial issues are off limits. Steve Hansen (bell jar expert) gives some brief descriptions of the vacuum trainers that are or have been available over the past decade or so - Varian, MKS, Science Source, American Vacuum Society. Links are provided to various data sheets, articles and online exercises. Steve, the forum moderator has experience in all of these.Keywords: vacuum, "vacuum trainer","bell jar" and/or belljar, MKSVarian, VPAL, VTS, sputtering, plasma

  10. A method for quantitative measurement of lumbar intervertebral disc structures: an intra- and inter-rater agreement and reliability study

    PubMed Central

    2013-01-01

    Background There is a shortage of agreement studies relevant for measuring changes over time in lumbar intervertebral disc structures. The objectives of this study were: 1) to develop a method for measurement of intervertebral disc height, anterior and posterior disc material and dural sac diameter using MRI, 2) to evaluate intra- and inter-rater agreement and reliability for the measurements included, and 3) to identify factors compromising agreement. Methods Measurements were performed on MRIs from 16 people with and 16 without lumbar disc herniation, purposefully chosen to represent all possible disc contours among participants in a general population study cohort. Using the new method, MRIs were measured twice by one rater and once by a second rater. Agreement on the sagittal start- and end-slice was evaluated using weighted Kappa. Length and volume measurements were conducted on available slices between intervertebral foramens, and cross-sectional areas (CSA) were calculated from length measurements and slice thickness. Results were reported as Bland and Altman’s limits of agreement (LOA) and intraclass correlation coefficients (ICC). Results Weighted Kappa (Kw (95% CI)) for start- and end-slice were: intra-: 0.82(0.60;0.97) & 0.71(0.43;0.93); inter-rater: 0.56(0.29;0.78) & 0.60(0.35;0.81). For length measurements, LOA ranged from [?1.0;1.0] mm to [?2.0;2.3] mm for intra-; and from [?1.1; 1.4] mm to [?2.6;2.0] mm for inter-rater. For volume measurements, LOA ranged from [?293;199] mm3 to [?582;382] mm3 for intra-, and from [?17;801] mm3 to [?450;713] mm3 for inter-rater. For CSAs, LOA ranged between [?21.3; 18.8] mm2 and [?31.2; 43.7] mm2 for intra-, and between [?10.8; 16.4] mm2 and [?64.6; 27.1] mm2 for inter-rater. In general, LOA as a proportion of mean values gradually decreased with increasing size of the measured structures. Agreement was compromised by difficulties in identifying the vertebral corners, the anterior and posterior boundaries of the intervertebral disc and the dural sac posterior boundary. With two exceptions, ICCs were above 0.81. Conclusions Length measurements and calculated CSAs of disc morphology and dural sac diameter from MRIs showed acceptable intra- and inter-rater agreement and reliability. However, caution should be taken when measuring very small structures and defining anatomical landmarks. PMID:23953197

  11. Radiation hard vacuum switch

    DOEpatents

    Boettcher, Gordon E. (Albuquerque, NM)

    1990-01-01

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction.

  12. Ptolemy relations for punctured discs

    E-print Network

    Baur, Karin

    2007-01-01

    We construct frieze patterns of type D_N with entries which are numbers of matchings between vertices and triangles of corresponding triangulations of a punctured disc. For triangulations corresponding to orientations of the Dynkin diagram of type D_N, we show that the numbers in the pattern can be interpreted as specialisations of cluster variables in the corresponding Fomin-Zelevinsky cluster algebra.

  13. Hydrodynamic instability in eccentric astrophysical discs

    NASA Astrophysics Data System (ADS)

    Barker, A. J.; Ogilvie, G. I.

    2014-12-01

    Eccentric Keplerian discs are believed to be unstable to three-dimensional hydrodynamical instabilities driven by the time-dependence of fluid properties around an orbit. These instabilities could lead to small-scale turbulence, and ultimately modify the global disc properties. We use a local model of an eccentric disc, derived in a companion paper, to compute the non-linear vertical (`breathing mode') oscillations of the disc. We then analyse their linear stability to locally axisymmetric disturbances for any disc eccentricity and eccentricity gradient using a numerical Floquet method. In the limit of small departures from a circular reference orbit, the instability of an isothermal disc is explained analytically. We also study analytically the small-scale instability of an eccentric neutrally stratified polytropic disc with any polytropic index using a Wentzel-Kramers-Brillouin (WKB) approximation. We find that eccentric discs are generically unstable to the parametric excitation of small-scale inertial waves. The non-linear evolution of these instabilities should be studied in numerical simulations, where we expect them to lead to a decay of the disc eccentricity and eccentricity gradient as well as to induce additional transport and mixing. Our results highlight that it is essential to consider the three-dimensional structure of eccentric discs, and their resulting vertical oscillatory flows, in order to correctly capture their evolution.

  14. Accretion Discs with Strong Toroidal Magnetic Fields

    E-print Network

    M. C. Begelman; J. E. Pringle

    2006-12-12

    Simulations and analytic arguments suggest that the turbulence driven by magnetorotational instability (MRI) in accretion discs can amplify the toroidal (azimuthal) component of the magnetic field to a point at which magnetic pressure exceeds the combined gas + radiation pressure in the disc. Arguing from the recent analysis by Pessah and Psaltis, and other MRI results in the literature, we conjecture that the limiting field strength for a thin disc is such that the Alfven speed roughly equals the geometric mean of the Keplerian speed and the gas sound speed. We examine the properties of such magnetically-dominated discs, and show that they resolve a number of outstanding problems in accretion disc theory. The discs would be thicker than standard (Shakura-Sunyaev) discs at the same radius and accretion rate, and would tend to have higher colour temperatures. If they transport angular momentum according to an alpha-prescription, they would be stable against the thermal and viscous instabilities that are found in standard disc models. In discs fuelling active galactic nuclei, magnetic pressure support could also alleviate the restriction on accretion rate imposed by disc self-gravity.

  15. Heating steels in vacuum

    SciTech Connect

    Marmer, E.N.

    1983-03-01

    It is recommended that high-strength and corrosion-resistant steels be heated in an electric vacuum furnace. Absence of oxidation and decarburization, decrease in the deformation of the part, increase in service life, plus safety, and nontoxicity in the shop, are cited as advantages. Annealing, carburizing, hardening, brazing, and sintering--all detailed-can be more efficiently accomplished in vacuum heating. As vacuum heating requires certain surface conditions, the compositions of residual mediums is studied. The microrelief and surface finish obtained after vacuum heating is determined. Annealing in a vacuum is compared to annealing in air, a depletion in manganese indicating a greater savings by use of vacuum. Ductility is also tested. The gas of special purity nitrogen is recommended for best results. In general, then, use of electric vacuum furnaces is recommended.

  16. Cloning and Characterization of Disc1, the Mouse Ortholog of DISC1 (Disrupted-in-Schizophrenia 1)

    Microsoft Academic Search

    Lei Ma; Yuan Liu; Betty Ky; Paul J. Shughrue; Christopher P. Austin; Jill A. Morris

    2002-01-01

    We cloned the mouse ortholog of DISC1 (Disrupted-in-Schizophrenia 1), a candidate gene for schizophrenia. Disc1 is 3163 nucleotides long and has 60% identity with the human DISC1. Disc1 encodes 851 amino acids and has 56% identity with the human protein. Disc1 maps to the DISC1 syntenic region in the mouse, and genomic structure is conserved. A Disc1 splice variant deletes

  17. Proto-planetary disc evolution and dispersal

    NASA Astrophysics Data System (ADS)

    Rosotti, Giovanni Pietro

    2015-05-01

    Planets form from gas and dust discs in orbit around young stars. The timescale for planet formation is constrained by the lifetime of these discs. The properties of the formed planetary systems depend thus on the evolution and final dispersal of the discs, which is the main topic of this thesis. Observations reveal the existence of a class of discs called "transitional", which lack dust in their inner regions. They are thought to be the last stage before the complete disc dispersal, and hence they may provide the key to understanding the mechanisms behind disc evolution. X-ray photoevaporation and planet formation have been studied as possible physical mechanisms responsible for the final dispersal of discs. However up to now, these two phenomena have been studied separately, neglecting any possible feedback or interaction. In this thesis we have investigated what is the interplay between these two processes. We show that the presence of a giant planet in a photo-evaporating disc can significantly shorten its lifetime, by cutting the inner regions from the mass reservoir in the exterior of the disc. This mechanism produces transition discs that for a given mass accretion rate have larger holes than in models considering only X-ray photo-evaporation, constituting a possible route to the formation of accreting transition discs with large holes. These discs are found in observations and still constitute a puzzle for the theory. Inclusion of the phenomenon called "thermal sweeping", a violent instability that can destroy a whole disc in as little as 10 4 years, shows that the outer disc left can be very short-lived (depending on the X-ray luminosity of the star), possibly explaining why very few non accreting transition discs are observed. However the mechanism does not seem to be efficient enough to reconcile with observations. In this thesis we also show that X-ray photo-evaporation naturally explains the observed correlation between stellar masses and accretion rates and is therefore the ideal candidate for driving disc evolution. Another process that can influence discs is a close encounter with another star. In this thesis we develop a model to study the effect of stellar dynamics in the natal stellar cluster on the discs, following for the first time at the same time the stellar dynamics together with the evolution of the discs. We find that, although close encounters with stars are unlikely to change significantly the mass of a disc, they can change substantially its size, hence imposing an upper limit on the observed disc radii. Finally, we investigated in this thesis whether discs can be reformed after their dispersal. If a star happens to be in a region that is currently forming stars, it can accrete material from the interstellar medium. This mechanism may result in the production of "second generation" discs such that in a given star forming region a few percent of stars may still possess a disc, in tentative agreement with observations of so called "old accretors", which are difficult to explain within the current paradigm of disc evolution and dispersal.

  18. Management of herniated intervertebral disks during saturation dives: a case report.

    PubMed

    Stevens, D M; Caras, B G; Flynn, E T; Dutka, A J; Thorp, J W; Thalmann, E D

    1992-05-01

    During research saturation dives at 5.0 and 5.5 atm abs, 2 divers developed an acute herniation of the nucleus pulposus of the L5-S1 intervertebral disk. In both cases the pain was severe enough to require intravenous morphine or intramuscular meperidine. Although the symptoms presented by these divers are frequently considered to be an indication for immediate surgical consultation, we decided that emergency decompression posed an unacceptable risk that decompression sickness (DCS) would develop in the region of acute inflammation. In both cases strict bedrest and medical therapy were performed at depth. In the first case, 12 h was spent at depth before initiating a standard U.S. Navy saturation decompression schedule with the chamber partial pressure of oxygen elevated to 0.50 atm abs. In the second case, a conservative He-N2-O2 trimix decompression schedule was followed to the surface. In both cases, no initial upward excursion was performed. The required decompression time was 57 h 24 min from 5.5 atm abs and 55 h 38 min from 5.0 atm abs. During the course of decompression, the first diver's neurologic exam improved and he required decreasing amounts of intravenous narcotic; we considered both to be evidence against DCS. The second diver continued to have pain and muscle spasm throughout decompression, however he did not develop motor, reflex, or sphincter abnormalities. Both divers have responded well to nonsurgical therapy. PMID:1534427

  19. On the theory of disc photoevaporation

    E-print Network

    Owen, James E; Ercolano, Barbara

    2011-01-01

    We discuss a hydrodynamical model for the dispersal of protoplanetary discs around young, low mass (100) luminosity ratios, the FUV constricts the X-ray flow and may dominate the mass-loss. Simulations of low mass discs with inner holes demonstrate a further stage of disc clearing, which we call `thermal sweeping'. This process occurs when the mid-plane pressure drops to sufficiently low values. At this stage a bound, warm, X-ray heated region becomes sufficiently large and unstable, such that the remaining disc material is cleared on approximately dynamical time-scales. This process significantly reduces the time taken to clear the outer regions of the disc, resulting in an expected transition disc population that will be dominated by accreting objects, as indicated by recent observations.

  20. Close-packing of growing discs

    SciTech Connect

    Bursill, L.A.; Xudong, F. (Melbourne Univ., Parkville (Australia). School of Physics)

    1988-12-01

    Spiral lattices are derived by allowing growing discs to aggregate under a close-packing rule. Both Fibonacci and Lucas numbers of visible spirals arise naturally, dependent only on the choice of growth centre. Both the rate of convergence towards an ideal spiral, and chirality, are determined by the initial placement of the first few discs (initial conditions). Thus the appearance of spiral packings is no more or less mysterious than the appearance of hexagonal packed arrays of equal discs.

  1. Stellar capture by an accretion disc

    E-print Network

    D. Vokrouhlicky; V. Karas

    1997-10-15

    Long-term evolution of a stellar orbit captured by a massive galactic center via successive interactions with an accretion disc has been examined. An analytical solution describing evolution of the stellar orbital parameters during the initial stage of the capture was found. Our results are applicable to thin Keplerian discs with an arbitrary radial distribution of density and rather general prescription for the star-disc interaction. Temporal evolution is given in the form of quadrature which can be carried out numerically.

  2. Enhancing cell migration in shape-memory alginate-collagen composite scaffolds: In vitro and ex vivo assessment for intervertebral disc repair.

    PubMed

    Guillaume, Olivier; Naqvi, Syeda Masooma; Lennon, Kerri; Buckley, Conor Timothy

    2015-04-01

    Lower lumbar disc disorders pose a significant problem in an aging society with substantial socioeconomic consequences. Both inner tissue (nucleus pulposus) and outer tissue (annulus fibrosus) of the intervertebral disc are affected by such debilitating disorders and can lead to disc herniation and lower back pain. In this study, we developed an alginate-collagen composite porous scaffold with shape-memory properties to fill defects occurring in annulus fibrosus tissue of degenerated intervertebral discs, which has the potential to be administered using minimal invasive surgery. In the first part of this work, we assessed how collagen incorporation on preformed alginate scaffolds influences the physical properties of the final composite scaffold. We also evaluated the ability of annulus fibrosus cells to attach, migrate, and proliferate on the composite alginate-collagen scaffolds compared to control scaffolds (alginate only). In vitro experiments, performed in intervertebral disc-like microenvironmental conditions (low glucose and low oxygen concentrations), revealed that for alginate only scaffolds, annulus fibrosus cells agglomerated in clusters with limited infiltration and migration capacity. In comparison, for alginate-collagen scaffolds, annulus fibrosus cells readily attached and colonized constructs, while preserving their typical fibroblastic-like cell morphology with spreading behavior and intense cytoskeleton expression. In a second part of this study, we investigated the effects of alginate-collagen scaffold when seeded with bone marrow derived mesenchymal stem cells. In vitro, we observed that alginate-collagen porous scaffolds supported cell proliferation and extracellular matrix deposition (collagen type I), with secretion amplified by the local release of transforming growth factor-?3. In addition, when cultured in ex vivo organ defect model, alginate-collagen scaffolds maintained viability of transplanted mesenchymal stem cells for up to 5 weeks. Taken together, these findings illustrate the advantages of incorporating collagen as a means to enhance cell migration and proliferation in porous scaffolds which could be used to augment tissue repair strategies. PMID:25376622

  3. EFFECT OF DISC HEIGHT AND DISC WEDGE ANGLE ON LUMBAR SPINE UNDER AXIAL COMPRESSIVE FORCE

    Microsoft Academic Search

    YUAN LI ZHOU; QING HANG ZHANG; EE CHON TEO

    Three-dimensional L4-L5 finite element (FE) models of three disc heights (9.5mm, 11.5mm, and 13.5mm) and three disc wedge angles (5º, 8 º, and 10 º) were developed to investigate their effect on L4-L5 lumbar motion segment under pure axial compressive loading. The FE predictions indicated that the axial disc displacement and the posterior disc bulge increased greatly with an increase

  4. A prospective study of the interrelationship between subjective and objective measures of disability before and 2 months after lumbar decompression surgery for disc herniation

    Microsoft Academic Search

    Anne F. Mannion; Jiri Dvorak; Markus Müntener; Dieter Grob

    2005-01-01

    The value of range of motion (ROM) as an indicator of impairment associated with spinal problems, and in monitoring changes in response to treatment, is a controversial issue. The aim of this study was to examine the interrelationship between subjective disability (Roland-Morris scores) and objectively measured impairment (ROM), both before and in response to spinal decompression surgery, in an older

  5. Symptomatic cervical disc herniation following a motor vehicle collision: return to work comparative study of workers' compensation versus personal injury insurance status

    Microsoft Academic Search

    Gaetano J. Scuderi; Andrew L. Sherman; Georgiy V. Brusovanik; Michael A. Pahl; Alexander R. Vaccaro

    2005-01-01

    Background contextPatients with approved workers' compensation injuries receive guaranteed compensation for the duration of their injury, whereas patients with personal injury claims are only compensated, if at all, at the time of a successful settlement or trial verdict at a time point distant from their injury.

  6. On the evolution of the protolunar disc.

    PubMed

    Ward, William R

    2014-09-13

    The structure and viscous evolution of a post-impact, protolunar disc is examined. The equations for a silicate disc in two-phase (vapour-liquid) equilibrium are employed to derive an analytical solution to vertical structure. Both a vertically mixed phase disc and a stratified disc, where a magma layer exists in the mid-plane surrounded by a vapour reservoir, are considered. The former largely reproduces the low gas mass fraction, x?1, profiles of the disc described in earlier literature that proposed that the disc would hover on the brink of gravitational instability. In the latter, the vapour layer has x?1 and is generally gravitationally stable, while the magma layer is vigorously unstable. The viscous evolution of the stratified model is then explored. Initially, the disc quickly settles to a quasi-steady state with a vapour reservoir containing the majority of the disc mass. The magma layer viscously spreads on a time scale of approximately 3-4 years, during which vapour continuously condenses into droplets that settle to the mid-plane, maintaining the magma surface density in spite of disc spreading. Material flowing inwards is accreted by the Earth; material flowing outwards past the Roche boundary can become incorporated into accreting moonlets. This evolution persists until the vapour reservoir is depleted in approximately 50-100 years, depending on its initial mass. PMID:25114314

  7. DSC Study of Collagen in Disc Disease.

    PubMed

    Skrzy?ski, S; Sionkowska, A; Marciniak, A

    2009-01-01

    Differential scanning calorimetry (DSC) has been used to estimate the effect of disc disease on the collagen helix-coil transition and morphology for tissue extracted from patients during surgical operation. Forty discs were obtained from patients with degenerative disc disease undergoing surgery for low back pain. The patients were in the age between 20 and 70 years old. The specimens were kept wet during DSC experiment. The data allow the comparison between thermal stability of collagen tissue from healthy patients and from patients suffering from disc disease. In the paper the comparison between thermal helix-coil transition for collagen fibers from patients suffering from disc disease and collagen fibers from healthy organisms has been discussed. The heating rate has an influence on the position on denaturation temperatures of collagen in disc tissues. Higher helix-coil transition temperature of collagen in degenerated disc suggests that additional intermolecular cross linking of collagen fibers occurs. Denaturation temperatures of collagen in degenerated male disc possess smaller values than in female ones. Disc disease induces changes in collagen structure and leads to formation of additional crosslinks between collagen fibers. PMID:20169086

  8. Leak locator for vacuum jacketed pipelines eliminates need for removal of outer jacket

    NASA Technical Reports Server (NTRS)

    Wells, G. H.

    1966-01-01

    Device for locating leaks in a vacuum-jacketed liquid-hydrogen transfer line consists of two Mylar discs, a source of nitrogen and helium gas, and a mass spectrometer. The outer jacket of the pipeline does not need to be removed for the locator to be used.

  9. The automatic detection of the optic disc location in retinal images using optic disc location regression

    Microsoft Academic Search

    M. D. Abramoff; M. Niemeijer

    2006-01-01

    The automatic detection of the position of the optic disc is an important step in the automatic analysis of retinal images. A method to detect the approximate position of the optic disc using kNN regression is presented. The method starts by building a regression model of the optic disc position. Using a prior vessel segmentation all vessel pixels are searched

  10. Misaligned angular momentum in hydrodynamic cosmological simulations: warps, outer discs and thick discs

    NASA Astrophysics Data System (ADS)

    Roškar, Rok; Debattista, Victor P.; Brooks, Alyson M.; Quinn, Thomas R.; Brook, Chris B.; Governato, Fabio; Dalcanton, Julianne J.; Wadsley, James

    2010-10-01

    We present a detailed analysis of a disc galaxy forming in a high-resolution fully cosmological simulation to investigate the nature of the outer regions of discs and their relevance for the disc formation process. Specifically, we focus on the phenomenon of misaligned disc components and find that the outer disc warp is a consequence of the misalignment between the inner disc and the surrounding hot gaseous halo. As the infalling cold gas sinks towards the centre of the galaxy, it is strongly torqued by the hot gas halo. By the time the fresh gas reaches the central disc-forming region, its angular momentum is completely aligned with the spin of the hot gas halo. If the spin of the hot gas halo, in turn, is not aligned with that of the inner disc, a misaligned outer disc forms, comprised of newly accreted material. The inner and outer components are misaligned with each other because they respond differently to infalling substructure and accretion. The warped disc feeds the main gas disc due to viscous angular momentum losses, but small amounts of star formation in the warp itself form a low-metallicity thick disc. We show that observations of resolved stellar populations in warped galaxies in the local Universe could provide evidence for the presence of these processes and therefore indirectly reveal ongoing gas accretion and the existence of hot gas haloes.

  11. Heating steels in vacuum

    Microsoft Academic Search

    Marmer

    1983-01-01

    It is recommended that high-strength and corrosion-resistant steels be heated in an electric vacuum furnace. Absence of oxidation and decarburization, decrease in the deformation of the part, increase in service life, plus safety, and nontoxicity in the shop, are cited as advantages. Annealing, carburizing, hardening, brazing, and sintering--all detailed-can be more efficiently accomplished in vacuum heating. As vacuum heating requires

  12. Vacuum probe surface sampler

    NASA Technical Reports Server (NTRS)

    Zahlava, B. A. (inventor)

    1973-01-01

    A vacuum probe surface sampler is described for rapidly sampling relatively large surface areas which possess relatively light loading densities of micro-organism, drug particles or the like. A vacuum head with a hollow handle connected to a suitable vacuum source is frictionally attached to a cone assembly terminating in a flared tip adapted to be passed over the surface to be sampled. A fine mesh screen carried by the vacuum head provides support for a membrane filter which collects the microorganisms or other particles. The head assembly is easily removed from the cone assembly without contacting the cone assembly with human hands.

  13. Theory of Black Hole Accretion Discs

    NASA Astrophysics Data System (ADS)

    Abramowicz, Marek A.; Björnsson, Gunnlaugur; Pringle, James E.

    2010-08-01

    Part I. Observations of Black Holes: 1. Black holes in our Galaxy: observations P. Charles; 2. Black holes in Active Galactic Nuclei: observations G. M. Madejski; Part II. Physics Close to a Black Hole: 3. Physics of black holes I. D. Novikov; 4. Physics of black hole accretion M. A. Abramowicz; Part III. Turbulence, Viscosity: 5. Disc turbulence and viscosity A. Brandenburg; Part IV. Radiative Processes: 6. The role of electron-positron pairs in accretion flows G. Björnsson; 7. Accretion disc-corona models and X/Y-ray spectra of accreting black holes J. Poutanen; 8. Emission lines: signatures of relativistic rotation A. C. Fabian; Part V. Accretion Discs: 9. Spectral tests of models for accretion disks around black holes J. H. Krolik; 10. Advection-dominated accretion around black holes R. Narayan, R. Mahadevan and E. Quataert; 11. Accretion disc instabilities and advection dominated accretion flows J.-P. Lasota; 12. Magnetic field and multi-phase gas in AGN A. Celotti and M. J. Rees; Part V. Discs in Binary Black Holes: 13. Supermassive binary black holes in galaxies P. Artymowicz; Part VI. Stability of Accretion Discs: 14. Large scale perturbation of an accretion disc by a black hole binary companion J. C. B. Papaloizou, C. Terquem and D. N. C. Lin; 15. Stable oscillations of black hole accretion discs M. Nowak and D. Lehr; Part VI. Coherant Structures: 16. Spotted discs A. Bracco, A. Provenzale, E. A. Spiegel and P. Yecko; Self-organized critically in accretion discs P. Wiita and Y. Xiong; Summary: old and new advances in black hole accretion disc theory R. Svensson.

  14. Theory of Black Hole Accretion Discs

    NASA Astrophysics Data System (ADS)

    Abramowicz, Marek A.; Björnsson, Gunnlaugur; Pringle, James E.

    1999-03-01

    Part I. Observations of Black Holes: 1. Black holes in our Galaxy: observations P. Charles; 2. Black holes in Active Galactic Nuclei: observations G. M. Madejski; Part II. Physics Close to a Black Hole: 3. Physics of black holes I. D. Novikov; 4. Physics of black hole accretion M. A. Abramowicz; Part III. Turbulence, Viscosity: 5. Disc turbulence and viscosity A. Brandenburg; Part IV. Radiative Processes: 6. The role of electron-positron pairs in accretion flows G. Björnsson; 7. Accretion disc-corona models and X/Y-ray spectra of accreting black holes J. Poutanen; 8. Emission lines: signatures of relativistic rotation A. C. Fabian; Part V. Accretion Discs: 9. Spectral tests of models for accretion disks around black holes J. H. Krolik; 10. Advection-dominated accretion around black holes R. Narayan, R. Mahadevan and E. Quataert; 11. Accretion disc instabilities and advection dominated accretion flows J.-P. Lasota; 12. Magnetic field and multi-phase gas in AGN A. Celotti and M. J. Rees; Part V. Discs in Binary Black Holes: 13. Supermassive binary black holes in galaxies P. Artymowicz; Part VI. Stability of Accretion Discs: 14. Large scale perturbation of an accretion disc by a black hole binary companion J. C. B. Papaloizou, C. Terquem and D. N. C. Lin; 15. Stable oscillations of black hole accretion discs M. Nowak and D. Lehr; Part VI. Coherant Structures: 16. Spotted discs A. Bracco, A. Provenzale, E. A. Spiegel and P. Yecko; Self-organized critically in accretion discs P. Wiita and Y. Xiong; Summary: old and new advances in black hole accretion disc theory R. Svensson.

  15. The properties of discs around planets and brown dwarfs as evidence for disc fragmentation

    NASA Astrophysics Data System (ADS)

    Stamatellos, Dimitris; Herczeg, Gregory J.

    2015-06-01

    Direct imaging searches have revealed many very low mass objects, including a small number of planetary-mass objects, as wide-orbit companions to young stars. The formation mechanism of these objects remains uncertain. In this paper, we present the predictions of the disc fragmentation model regarding the properties of the discs around such low-mass objects. We find that the discs around objects that have formed by fragmentation in discs hosted by Sun-like stars (referred to as parent discs and parent stars) are more massive than expected from the Mdisc-M* relation (which is derived for stars with masses M* > 0.2 M?). Accordingly, the accretion rates on to these objects are also higher than expected from the dot{M}_*-M_* relation. Moreover, there is no significant correlation between the mass of the brown dwarf or planet with the mass of its disc nor with the accretion rate from the disc on to it. The discs around objects that form by disc fragmentation have larger than expected masses as they accrete gas from the disc of their parent star during the first few kyr after they form. The amount of gas that they accrete and therefore their mass depend on how they move in their parent disc and how they interact with it. Observations of disc masses and accretion rates on to very low mass objects are consistent with the predictions of the disc fragmentation model. Future observations (e.g. by Atacama Large Millimeter/submillimeter Array) of disc masses and accretion rates on to substellar objects that have even lower masses (young planets and young, low-mass brown dwarfs), where the scaling relations predicted by the disc fragmentation model diverge significantly from the corresponding relations established for higher mass stars, will test the predictions of this model.

  16. Idiopathic spinal cord herniation: Clinical review and report of three cases

    PubMed Central

    Summers, Johanne C.; Balasubramani, Yagnesh V.; Chan, Patrick C. H.; Rosenfeld, Jeffrey V.

    2013-01-01

    Idiopathic spinal cord herniation (ISCH) is a rare condition, of unknown pathogenesis, that primarily affects the thoracic spinal cord. It is characterized by ventral displacement of the spinal cord through a dural defect. The aim of this study was to review the literature and to present a retrospective single center experience with three cases of ISCH. The literature review analyzed a total of 78 relevant publications on ISCH, which included a total of 171 patients, supplemented with 3 patients treated at our institution. Numerous case reports have demonstrated improvement in clinical outcomes after surgery; however, follow-up is predominantly short, data are incomplete, the condition is frequently misdiagnosed, and it is difficult to predict which patients will benefit from surgery. We identified 159 cases treated with surgical management. The mean symptom duration was 54 months, and the mean follow-up 33 months. The result at follow-up was improved neurological outcome in 74%, unchanged result in 18%, and worse outcome in 8%. There were 15 cases of conservative management, with mean symptom duration 52 months and mean follow-up 33 months. The neurological outcome was unchanged in 100%. ISCH is a rare condition causing progressive thoracic myelopathy, and the natural history is unknown. There is a lack of evidence-based treatment strategies, and the majority of cases are treated with surgical management at diagnosis. Management of ISCH needs to be individualized for each patient, and clinicians should be encouraged to report new cases, standardize case reports, and ensure long-term follow-up. PMID:24049553

  17. Mechanisms of cerebellar tonsil herniation in patients with Chiari malformations as guide to clinical management

    PubMed Central

    Nishikawa, Misao; Kula, Roger W.; Dlugacz, Yosef D.

    2010-01-01

    Background The pathogenesis of Chiari malformations is incompletely understood. We tested the hypothesis that different etiologies have different mechanisms of cerebellar tonsil herniation (CTH), as revealed by posterior cranial fossa (PCF) morphology. Methods In 741 patients with Chiari malformation type I (CM-I) and 11 patients with Chiari malformation type II (CM-II), the size of the occipital enchondrium and volume of the PCF (PCFV) were measured on reconstructed 2D-CT and MR images of the skull. Measurements were compared with those in 80 age- and sex-matched healthy control individuals, and the results were correlated with clinical findings. Results Significant reductions of PCF size and volume were present in 388 patients with classical CM-I, 11 patients with CM-II, and five patients with CM-I and craniosynostosis. Occipital bone size and PCFV were normal in 225 patients with CM-I and occipitoatlantoaxial joint instability, 55 patients with CM-I and tethered cord syndrome (TCS), 30 patients with CM-I and intracranial mass lesions, and 28 patients with CM-I and lumboperitoneal shunts. Ten patients had miscellaneous etiologies. The size and area of the foramen magnum were significantly smaller in patients with classical CM-I and CM-I occurring with craniosynostosis and significantly larger in patients with CM-II and CM-I occurring with TCS. Conclusions Important clues concerning the pathogenesis of CTH were provided by morphometric measurements of the PCF. When these assessments were correlated with etiological factors, the following causal mechanisms were suggested: (1) cranial constriction; (2) cranial settling; (3) spinal cord tethering; (4) intracranial hypertension; and (5) intraspinal hypotension. PMID:20440631

  18. Pressure transduction and fluid evacuation during conventional negative pressure wound therapy of the open abdomen and NPWT using a protective disc over the intestines

    PubMed Central

    2012-01-01

    Background Negative pressure wound therapy (NPWT) has gained acceptance among surgeons, for the treatment of open abdomen, since very high closure rates have been reported with this method, compared to other kinds of wound management for the open abdomen. However, the method has occasionally been associated with increased development of fistulae. We have previously shown that NPWT induces ischemia in the underlying small intestines close to the vacuum source, and that a protective disc placed between the intestines and the vacuum source prevents the induction of ischemia. In this study we compare pressure transduction and fluid evacuation of the open abdomen with conventional NPWT and NPWT with a protective disc. Methods Six pigs underwent midline incision and the application of conventional NPWT and NPWT with a protective disc between the intestines and the vacuum source. The pressure transduction was measured centrally beneath the dressing, and at the anterior abdominal wall, before and after the application of topical negative pressures of -50, -70 and -120 mmHg. The drainage of fluid from the abdomen was measured, with and without the protective disc. Results Abdominal drainage was significantly better (p < 0. 001) using NPWT with the protective disc at -120 mmHg (439 ± 25 ml vs. 239 ± 31 ml), at -70 mmHg (341 ± 27 ml vs. 166 ± 9 ml) and at -50 mmHg (350 ± 50 ml vs. 151 ± 21 ml) than with conventional NPWT. The pressure transduction was more even at all pressure levels using NPWT with the protective disc than with conventional NPWT. Conclusions The drainage of the open abdomen was significantly more effective when using NWPT with the protective disc than with conventional NWPT. This is believed to be due to the more even and effective pressure transduction in the open abdomen using a protective disc in combination with NPWT. PMID:22443416

  19. Misunderstanding of foot drop in a patient with charcot-marie-tooth disease and lumbar disk herniation.

    PubMed

    Han, Youngmin; Kim, Kyoung-Tae; Cho, Dae-Chul; Sung, Joo-Kyung

    2015-04-01

    We report the case of 57-year-old woman diagnosed with Charcot-Marie-Tooth (CMT) disease and lumbar disk herniation (LDH). She had left leg weakness and foot numbness, foot deformity (muscle atrophy, high arch, and clawed toes). The lumbar spine MRI showed LDH at L4-5. Additionally, electrophysiology results were consistent with chronic peripheral motor-sensory polyneuropathy (axonopathy). In genetic testing, 17p11.2-p12 duplication/deletions characteristic of CMT disease were observed. We confirmed the patient's diagnosis as CMT disease and used conservative treatment. PMID:25932299

  20. Optic Disc Segmentation in Retinal Images

    Microsoft Academic Search

    Radim Chrástek; Matthias Wolf; Klaus Donath; Georg Michelson; Heinrich Niemann

    2002-01-01

    Abstract: Retinal images give unique diagnostic information not onlyabout eye disease but about other organs as well [1]. To give the physiciansa tool for objective quantitative assessment of the retina, automatedmethods have been developed. In this paper an automated methodfor the optic disc segmentation is presented. The method consists of 4steps: localization of the optic disc, nonlinearltering, Canny edge detectorand

  1. Counterrotating stars in simulated galaxy discs

    NASA Astrophysics Data System (ADS)

    Algorry, David G.; Navarro, Julio F.; Abadi, Mario G.; Sales, Laura V.; Steinmetz, Matthias; Piontek, Franziska

    2014-02-01

    Counterrotating stars in disc galaxies are a puzzling dynamical feature whose origin has been ascribed to either satellite accretion events or to disc instabilities triggered by deviations from axisymmetry. We use a cosmological simulation of the formation of a disc galaxy to show that counterrotating stellar disc components may arise naturally in hierarchically clustering scenarios even in the absence of merging. The simulated disc galaxy consists of two coplanar, overlapping stellar components with opposite spins: an inner counterrotating bar-like structure made up mostly of old stars surrounded by an extended, rotationally supported disc of younger stars. The opposite-spin components originate from material accreted from two distinct filamentary structures which at turn around, when their net spin is acquired, intersect delineating a `V'-like structure. Each filament torques the other in opposite directions; the filament that first drains into the galaxy forms the inner counterrotating bar, while material accreted from the other filament forms the outer disc. Mergers do not play a substantial role and most stars in the galaxy are formed in situ; only 9 per cent of all stars are contributed by accretion events. The formation scenario we describe here implies a significant age difference between the co- and counterrotating components, which may be used to discriminate between competing scenarios for the origin of counterrotating stars in disc galaxies.

  2. Spiral waves in accretion discs - theory

    E-print Network

    Henri M. J. Boffin

    2001-10-09

    Spirals shocks have been widely studied in the context of galactic dynamics and protostellar discs. They may however also play an important role in some classes of close binary stars, and more particularly in cataclysmic variables. In this paper, we review the physics of spirals waves in accretion discs, present the results of numerical simulations and consider whether theory can be reconcilied with observations.

  3. On the reliability of protostellar disc mass measurements and the existence of fragmenting discs

    NASA Astrophysics Data System (ADS)

    Dunham, Michael M.; Vorobyov, Eduard I.; Arce, Héctor G.

    2014-10-01

    We couple non-magnetic, hydrodynamical simulations of collapsing protostellar cores with radiative transfer evolutionary models to generate synthetic observations. We then use these synthetic observations to investigate the extent to which a simple method for measuring protostellar disc masses used in the literature recovers the intrinsic masses of the discs formed in the simulations. We evaluate the effects of contamination from the surrounding core, partially resolving out the disc, optical depth, fixed assumed dust temperatures, inclination, and the dust opacity law. We show that the combination of these effects can lead to disc mass underestimates by up to factors of 2-3 at millimetre wavelengths and up to an order of magnitude or larger at submillimetre wavelengths. The optically thin portions of protostellar discs are generally cooler in the Class I stage than the Class 0 stage since Class I discs are typically larger and more optically thick, and thus more shielded. The observed disc mass distribution closely resembles the intrinsic distribution if this effect is taken into account, especially at millimetre wavelengths where optical depth effects are minimized. Approximately 50-70 per cent of protostellar discs observed to date with this method are consistent with the masses of the gravitationally unstable discs formed in the simulations, suggesting that at least some protostellar discs are likely sufficiently massive to fragment. We emphasize key future work needed to confirm these results, including assembling larger, less biased samples, and using molecular line observations to distinguish between rotationally supported, Keplerian discs and magnetically supported pseudodiscs.

  4. Chapter 13. The Vacuum System

    E-print Network

    Brookhaven National Laboratory - Experiment 821

    to the exact radius for a 28 degree arc. A short aluminum bellows adapter is placed between each vacuum chamberChapter 13. The Vacuum System Revised February 1994 13.1. The Vacuum Chambers A plan view of the assembled vacuum chamber ring is shown in Fig. 13.1.1. The vacuum chamber ring includes twelve 28 degree

  5. Photon acceleration in vacuum

    E-print Network

    J. T. Mendonca; M. Marklund; P. K. Shukla; G. Brodin

    2006-08-16

    A new process associated with the nonlinear optical properties of the electromagnetic vacuum, as predicted by quantum electrodynamics, is described. This can be called photon acceleration in vacuum, and corresponds to the frequency shift that takes place when a given test photon interacts with an intense beam of background radiation.

  6. Vacuum Arc Anode Phenomena

    Microsoft Academic Search

    H. Craig Miller

    1983-01-01

    This paper briefly reviews anode phenomena in vacuum arcs, specially experimental work. It discusses, in succession, arc modes at the anode, anode temperature measurements, anode ions, transitions of the arc into various modes (principally the anode spot mode), and theoretical explanations of anode phenomena. The two most common anode modes in a vacuum arc are a low current mode where

  7. Bending Instabilities in Magnetized Accretion Discs

    E-print Network

    Vasso Agapitou; John C. B. Papaloizou; Caroline Terquem

    1997-07-29

    We study the global bending modes of a thin annular disc subject to both an internally generated magnetic field and a magnetic field due to a dipole embedded in the central star with axis aligned with the disc rotation axis. When there is a significant inner region of the disc corotating with the star, we find spectra of unstable bending modes. These may lead to elevation of the disc above the original symmetry plane facilitating accretion along the magnetospheric field lines. The resulting non-axisymmetric disc configuration may result in the creation of hot spots on the stellar surface and the periodic photometric variations observed in many classical T Tauri stars (CTTS). Time-dependent behaviour may occur including the shadowing of the central source in magnetic accretors even when the dipole and rotation axes are aligned.

  8. The quantum vacuum

    E-print Network

    G. S. Paraoanu

    2014-12-12

    The vacuum is the lowest energy state of a field in a certain region of space. This definition implies that no particles can be present in the vacuum state. In classical physics, the only features of vacuum are those of its geometry. For example, in the general theory of relativity the geometry is a dynamical structure that guides the motion of matter, and, in turn, it is bent and curved by the presence of matter. Other than this, the classical vacuum is a structure void of any physical properties, since classically properties are strictly associated with physical objects such as particles and finite-amplitude fields. The situation is very different in quantum physics. As I will show in this paper, the difference stems from the fact that in quantum physics the properties are not strictly tied to objects. We know for example that physical properties come into existence - as values of observables - only when the object is measured. Thus, quantum physics allows us to detach properties from objects. This has consequences: one does not need pre-existing real objects to create actual properties, and indeed under certain perturbations the quantum vacuum produces observable effects such as energy shifts and creation of particles. An open question is if by necessity the vacuum comes with an embedded geometry, and if it is possible to construct viable physical theories in which geometry is detached from the vacuum.

  9. Tidal Warping of Be Star Decretion Discs

    E-print Network

    Martin, Rebecca G; Tout, Christopher A; Lubow, Stephen H

    2011-01-01

    Rapidly rotating Be stars are observed as shell stars when the decretion disc is viewed edge on. Transitions between the two implies that the discs may be warped and precessing. Type II X-ray outbursts are thought to occur when the warped disc interacts with the fast stellar wind. We suggest that tides from a misaligned companion neutron star can cause the observed effects. We make numerical models of a Be star decretion disc in which the spin of the Be star is misaligned with the orbital axis of a neutron star companion. Tidal torques from the neutron star truncate the disc at a radius small enough that the neutron star orbit does not intersect the disc unless the eccentricity or misalignment is very large. A magnetic torque from the Be star that is largest at the equator, where the rotation is fastest, is approximated by an inner boundary condition. There are large oscillations in the mass and inclination of the disc as it moves towards a steady state. These large variations may explain the observed changes...

  10. Thermophoretic vacuum wand

    DOEpatents

    Klebanoff, Leonard Elliott (San Ramon, CA); Rader, Daniel John (Lafayette, CA)

    2000-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  11. Thermophoretic vacuum wand

    DOEpatents

    Klebanoff, Leonard Elliott (San Ramon, CA); Rader, Daniel John (Lafayette, CA)

    2001-01-01

    A thermophoretic vacuum wand that is particularly suited for transporting articles in a cleanroom environment so that potential particle contaminants in the air do not become adhered to the surface of the article is described. The wand includes a housing having a platen with a front surface with suction port(s) through the platen; a vacuum source for applying a negative pressure to the suction port(s); and heating device for the object. Heating the article when it is held by the vacuum wand affords thermophoretic protection that effectively prevents particles in the air from depositing onto the article.

  12. Evading death by vacuum

    E-print Network

    A. Barroso; P. M. Ferreira; I. P. Ivanov; Rui Santos; João P. Silva

    2013-03-15

    In the Standard Model, the Higgs potential allows only one minimum at tree-level. But the open possibility that there might be two scalar doublets enriches the vacuum structure, allowing for the risk that we might now be in a metastable state, which we dub the panic vacuum. Current experiments at the LHC are probing the Higgs particle predicted as a result of the spontaneous symmetry breaking. Remarkably, in the two Higgs model with a softly broken U(1) symmetry, the LHC experiments already preclude panic vacuum solutions.

  13. Vacuum tight window through which a high power laser beam and a high energy particle beam can be transmitted within close proximity to each other

    SciTech Connect

    Kimura, W.D.

    1984-05-22

    An apparatus and method by which a high-power laser beam and a high-energy particle beam may enter or exit a region, typically filled with gas, to or from another region, typically under vacuum. The two beams are spaced about 3-4 mm apart center-to-center at the entry/exit point and no gas is permitted to leak into the vacuum region. A disc of material capable of resisting high radiation fluxes without forming color centers is sealed into a metallic holding block. Prior to sealing of the disc, a hole approximately 0.16 cm is drilled into the disc while the disc is tilted at or above Brewster's angle forming an eliptical hole. A thin film, approximately 6000 A, indium metallization is sputtered in a circular pattern about the hole and around the edges of a beryllium disc. An indium disc is then sandwiched between the disc with the hole and the beryllium disc touching the indium metallization on each piece.

  14. Steroid treatment can inhibit nuclear localization of members of the NF-?B pathway in human disc cells stimulated with TNF-?.

    PubMed

    Quan, Meiling; Park, Sang-Eun; Lin, Zhenhua; Hong, Myung-Wha; Park, Seong-Yel; Kim, Young-Yul

    2015-07-01

    Steroid applications are able to repress inflammatory activity in various conditions, including herniation of the nucleus pulposus (HNP), by inhibiting tumour necrosis factor (TNF)-?, but the effects of long-term use are unknown. Here, we investigated the effect of dexamethasone (DEXA) on TNF-?-stimulated intervertebral disc cells by monitoring the expression and localization of NF-?B in the cytoplasm and nucleus. Cultured human intervertebral disc cells were left untreated or treated with only TNF-?, only DEXA, or with TNF-? and DEXA simultaneously. Cytoplasmic and nuclear proteins were extracted and Western blotted after 10 min, 1 or 2 h, to evaluate the expression of p50, p65, p52, and p100 (components of NF-?B). Immunofluorescence analysis was used to determine the subcellular localization of the proteins at 1 h. DEXA had limited effects on NF-?B expression in TNF-?-stimulated disc cells within the first 10 min. At 1 h, DEXA prevented the TNF-?-stimulated translocation of p50, p52, and p65. After 2 h, DEXA reduced the nuclear expression of p50, p65, and p52. Thus, DEXA resulted in delayed expression of NF-?B components and inhibited the translocation of p50, p52, and p65 to the nucleus, which would prevent expression of the corresponding genes. Therefore, following stimulation with TNF-?, transcriptional regulation of NF-?B in disc cells is mainly mediated via the classical pathway, but also to some extent via the alternative pathway. Hence, blockade of sub-acute inflammatory changes in HNP can be achieved by early injection of steroids, whereas long-term injection of a steroid may initiate NF-?B autophosphorylation. PMID:25037120

  15. DISC1 genetics, biology and psychiatric illness

    PubMed Central

    THOMSON, Pippa A.; MALAVASI, Elise L.V.; GRÜNEWALD, Ellen; SOARES, Dinesh C.; BORKOWSKA, Malgorzata; MILLAR, J. Kirsty

    2012-01-01

    Psychiatric disorders are highly heritable, and in many individuals likely arise from the combined effects of genes and the environment. A substantial body of evidence points towards DISC1 being one of the genes that influence risk of schizophrenia, bipolar disorder and depression, and functional studies of DISC1 consequently have the potential to reveal much about the pathways that lead to major mental illness. Here, we review the evidence that DISC1 influences disease risk through effects upon multiple critical pathways in the developing and adult brain. PMID:23550053

  16. Vacuum mechatronics first international workshop

    SciTech Connect

    Belinski, S.E.; Shirazi, M.; Hackwood, S.; Beni, G. (eds.) (California Univ., Santa Barbara, CA (USA))

    1989-01-01

    This report contains papers on the following topics: proposed epitaxial thin film growth in the ultra-vacuum of space; particle monitoring and control in vacuum processing equipment; electrostatic dust collector for use in vacuum systems; materials evaluation of an electrically noisy vacuum slip ring assembly; an overview of lubrication and associated materials for vacuum service; the usage of lubricants in a vacuum environment; guidelines and practical applications for lubrication in vacuum; recent development in leak detector and calibrator designs; the durability of ballscrews for ultrahigh vacuum; vacuum-compatible robot for self-contained manufacturing systems; the design, fabrication, and assembly of an advanced vacuum robotics system for space payload calibration; design criteria for mechanisms used in space; and concepts and requirements for semiconductor multiprocess integration in vacuum. These papers are indexed separately elsewhere.

  17. New strategies for disc repair: novel preclinical trials

    Microsoft Academic Search

    Joji Mochida

    2005-01-01

    Degeneration of lumbar intervertebral discs is a major cause of low back complaints, an irreversible occurrence with no currently available treatment. Furthermore, various surgical procedures can accelerate disc degeneration. On the other hand, recent experimental studies on disc cells have demonstrated an important role for the nucleus pulposus in preserving overall disc structure. The author’s group has already found that

  18. 21 CFR 866.1620 - Antimicrobial susceptibility test disc.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro...bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is...

  19. 21 CFR 866.1620 - Antimicrobial susceptibility test disc.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro...bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is...

  20. 21 CFR 866.1620 - Antimicrobial susceptibility test disc.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...antimicrobic-impregnated paper discs used to measure by a disc-agar diffusion technique or a disc-broth elution technique the in vitro...bacterial pathogens to antimicrobial agents. In the disc-agar diffusion technique, bacterial susceptibility is...

  1. Cervical intervertebral disc injury during simulated frontal impact

    Microsoft Academic Search

    S. Ito; P. C. Ivancic; A. M. Pearson; Y. Tominaga; S. E. Gimenez; W. Rubin; Manohar M. Panjabi

    2005-01-01

    Cervical disc injury due to frontal impact has been observed in both clinical and biomechanical investigations; however, there is a lack of data that elucidate the mechanisms of disc injury during these collisions. The goals of the current study were to determine the peak dynamic disc annular tissue strain and disc shear strain during simulated frontal impact of the whole

  2. Supermite vacuum interface design

    NASA Astrophysics Data System (ADS)

    Moore, W. B.; Stinnett, R. W.; McDaniel, D. H.

    A new water plastic vacuum interface has been designed for Sandia Laboratory's Supermite (2.8 MV, 2.2 ohm) accelerator. This design was based on the PBFA I vacuum interface. Electrostatic field plots show that in positive polarity the water feed to the PBFA I interface will fail at 2 MV on Supermite. This is confirmed by positive polarity experiments and field plots using the PBFA I style vacuum interface at the Naval Research Labs. Modifications to the water section geometry to increase the water breakdown strength in positive polarity result in equivalent electric field grading at the plastic vacuum interface but allow positive polarity operation at voltages up to 3.1 MV. This is accomplished by incorporating a dielectric field shaper which significantly improves the electric field grading across the insulator.

  3. Vacuum Camera Cooler

    NASA Technical Reports Server (NTRS)

    Laugen, Geoffrey A.

    2011-01-01

    Acquiring cheap, moving video was impossible in a vacuum environment, due to camera overheating. This overheating is brought on by the lack of cooling media in vacuum. A water-jacketed camera cooler enclosure machined and assembled from copper plate and tube has been developed. The camera cooler (see figure) is cup-shaped and cooled by circulating water or nitrogen gas through copper tubing. The camera, a store-bought "spy type," is not designed to work in a vacuum. With some modifications the unit can be thermally connected when mounted in the cup portion of the camera cooler. The thermal conductivity is provided by copper tape between parts of the camera and the cooled enclosure. During initial testing of the demonstration unit, the camera cooler kept the CPU (central processing unit) of this video camera at operating temperature. This development allowed video recording of an in-progress test, within a vacuum environment.

  4. III. Vacuum PumpsIII. Vacuum Pumps Gas transfer

    E-print Network

    Liu, Kai

    : Oil Diffusion PumpB. High Vacuum: Oil Diffusion Pump (Wet, Gas Transfer)(Wet, Gas Transfer, Screw High vacuum Oil diffusion, Turbomolecular, Cryo, Ion Auxiliary Titanium Sublimation, LN2 Liu, UCDIII. Vacuum PumpsIII. Vacuum Pumps Mechanism Gas transfer Gas capture FunctionFunction Roughing

  5. Total disc replacement surgery for symptomatic degenerative lumbar disc disease: a systematic review of the literature

    Microsoft Academic Search

    Karin D. van den Eerenbeemt; Raymond W. Ostelo; Barend J. van Royen; Wilco C. Peul; Maurits W. van Tulder

    2010-01-01

    The objective of this study is to evaluate the effectiveness and safety of total disc replacement surgery compared with spinal\\u000a fusion in patients with symptomatic lumbar disc degeneration. Low back pain (LBP), a major health problem in Western countries,\\u000a can be caused by a variety of pathologies, one of which is degenerative disc disease (DDD). When conservative treatment fails,\\u000a surgery

  6. Vertical cup\\/disc ratio in relation to optic disc size: its value in the assessment of the glaucoma suspect

    Microsoft Academic Search

    David F Garway-Heath; Simon T Ruben; Ananth Viswanathan; Roger A Hitchings

    1998-01-01

    AIMSThe vertical cup\\/disc ratio (CDR) has long been used in the assessment of the glaucoma suspect, though the wide range of CDR values in the normal population limits its use. Cup size is related physiologically to disc size and pathologically to glaucomatous damage. Disc size can be measured at the slit lamp as the vertical disc diameter (DD). The ability

  7. Planet formation in self-gravitating discs 

    E-print Network

    Gibbons, Peter George

    2013-11-28

    The work performed here studies particle dynamics in local two-dimensional simulations of self-gravitating accretion discs with a simple cooling law. It is well known that the structure which arises in the gaseous component ...

  8. Disc valve for sampling erosive process streams

    DOEpatents

    Mrochek, John E. (Oak Ridge, TN); Dinsmore, Stanley R. (Norris, TN); Chandler, Edward W. (Knoxville, TN)

    1986-01-01

    A four-port disc valve for sampling erosive, high temperature process streams. A rotatable disc defining opposed first and second sampling cavities rotates between fired faceplates defining flow passageways positioned to be alternatively in axial alignment with the first and second cavities. Silicon carbide inserts and liners composed of .alpha. silicon carbide are provided in the faceplates and in the sampling cavities to limit erosion while providing lubricity for a smooth and precise operation when used under harsh process conditions.

  9. Investigation of cryogenic rupture disc design

    NASA Technical Reports Server (NTRS)

    Keough, J. B.; Oldland, A. H.

    1973-01-01

    Rupture disc designs of both the active (command actuated) and passive (pressure ruptured) types were evaluated for performance characteristics at cryogenic temperatures and for capability to operate in a variety of cryogens, including gaseous and liquid fluorine. The test results, coupled with information from literature and industry searches, were used to establish a statement of design criteria and recommended practices for application of rupture discs to cryogenic rocket propellant feed and vent systems.

  10. Kinematic structures in galactic disc simulations

    NASA Astrophysics Data System (ADS)

    Roca-Fàbrega, S.; Romero-Gómez, M.; Figueras, F.; Antoja, T.; Valenzuela, O.

    2011-10-01

    N-body and test particle simulations have been used to characterize the stellar streams in the galactic discs of Milky Way type galaxies. Tools such as the second and third order moments of the velocity ellipsoid and clustering methods -EM-WEKA and FoF- allow characterizing these kinematic structures and linking them to the stellar overdensities and to the resonant regions all through the disc.

  11. Mach disc formation in cylindrical recovery systems

    SciTech Connect

    Morris, C.E.; McQueen, R.G.; Marsh, S.P.

    1983-01-01

    Cylindrical recovery systems have been used to shock-load polymers to pressures exceeding 50 GPa. In order to determine the pressures generated in these recovery systems the formation of the Mach disc on axis and its approach to steady state was monitored. The relation of the Mach disc diameter to the lateral dimension of the high explosive used to compress the polymer samples was also investigated.

  12. Particle Acceleration in (by) Accretion Discs

    E-print Network

    J. I. Katz

    1992-05-04

    I present a model for acceleration of protons by the second-order Fermi process acting on randomly scrambled magnetic flux arches above an accretion disc. The accelerated protons collide with thermal protons in the disc, producing degraded energetic protons, charged and neutral pions, and neutrons. The pions produce gamma-rays by spontaneous decay of $\\pi^0$ and by bremsstrahlung and Compton processes following the decay of $\\pi^\\pm$ to $e^\\pm$.

  13. Theory of Disc-Like Crystal Growth

    Microsoft Academic Search

    Jian-Jun Xu; Junichiro Shimizu

    2004-01-01

    The present paper is concerned with disc-like crystal growth from a pure undercooled melt. We assume that the growth of the top\\/bottom interface of the disc is very slow, dominated by the kinetic effect, while the growth of its side-interface is much faster, dominated by heat diffusion mechanism. We obtained the uniformly valid asymptotic solution for the basic state in

  14. Optic disc morphology--rethinking shape.

    PubMed

    Sanfilippo, Paul G; Cardini, Andrea; Hewitt, Alex W; Crowston, Jonathan G; Mackey, David A

    2009-07-01

    Morphometrics, a branch of morphology, represents the study of size and shape components of biological form and their variation in the population. Assessment of optic disc morphology is essential in the diagnosis and management of many ophthalmic disorders. Much work has been performed to characterize size-related parameters of the optic disc; however, limited information is available on shape variation in the general population. In contrast to optic disc or cup sizes, which are conceptually meaningful variables with a defined unit of measurement, there are few metric constructs by which to quantify, visualize and interpret variation in optic disc or cup shape. This has significance in ophthalmic diseases with a genetic basis as recent evidence has suggested that optic disc shape may be heritable. Conventional optic disc shape measures of 'ovality' and 'form-factor' reduce a complex structure to a single number and eliminate information of potential diagnostic relevance from further analyses. The recent advent of 'geometric morphometrics', a branch of statistics that incorporates tools from geometry, biometrics and computer graphics in the quantitative analysis of biological forms, has enabled spatial relationships in shape data to be retained during analysis. The analytical methods employed in geometric morphometrics can be separated into two distinct groups: landmark-based (e.g. Procrustes analysis, thin-plate splines) and boundary outline techniques (e.g. Fourier analysis). In this review, we summarize current approaches to the study of optic disc morphology, discuss the underlying theory of geometric morphometrics within the context of analytical techniques and then explore the contemporary relevance of the subject matter to several biological fields. Finally we illustrate the potential application of geometric morphometrics to the specific problem of optic disc shape and glaucoma assessment. PMID:19520180

  15. Electron beam recording of optical disc

    Microsoft Academic Search

    Giles Cartwright; Gerald Reynolds; Chris Baylis; Adrian Pearce; Colin Dix; Nick Ogilvie

    2002-01-01

    The Nimbus Technology & Engineering e?Beam Mastering System was developed to gain a large improvement in optical disc and structured hard disc recording capacity, significantly more than is possible from deep UV and SIL mastering. The current electron beam recorder is essentially a production machine capable of making full-length exposures at capacities of up to 50GB with a simple low-cost

  16. Optic disc anomalies and frontonasal dysplasia

    PubMed Central

    Hodgkins, P; Lees, M; Lawson, J; Reardon, W; Leitch, J; Thorogood, P; Winter, R; Taylor, D

    1998-01-01

    AIMS—To document the optic disc abnormalities in patients with frontonasal dysplasia in association with basal encephalocele.?METHODS—Names and hospital numbers of patients with midline clefts were obtained from the ophthalmology and genetics database. Six patients were identified who had the following common findings: midline facial cleft with midline cleft lip and palate; hypertelorism; absent corpus callosum; basal (sphenoethmoidal) encephalocele; and pituitary deficiency (five out of six cases). Ophthalmic examination was performed with fundal photography where possible.?RESULTS—Two patients had unilateral and one a bilateral peripapillary staphyloma. Two patients had bilateral optic disc hypoplasia and one appeared to have a peripapillary staphyloma in one eye and a morning glory disc in the other.?CONCLUSION—Optic disc abnormalities were found in all patients with this constellation of clinical findings. This association appears to represent a distinct subgroup within the spectrum of frontonasal dysplasia. The presence of midline facial anomalies and any dysplastic disc should alert the physician as to the presence of an encephalocele.?? Keywords: frontonasal dysplasia; optic disc; encephalocele PMID:9602627

  17. Turbulent drag reduction through oscillating discs

    E-print Network

    Wise, Daniel J

    2014-01-01

    The changes of a turbulent channel flow subjected to oscillations of wall flush-mounted rigid discs are studied by means of direct numerical simulations. The Reynolds number is $R_\\tau$=$180$, based on the friction velocity of the stationary-wall case and the half channel height. The primary effect of the wall forcing is the sustained reduction of wall-shear stress, which reaches a maximum of 20%. A parametric study on the disc diameter, maximum tip velocity, and oscillation period is presented, with the aim to identify the optimal parameters which guarantee maximum drag reduction and maximum net energy saving, computed by taking into account the power spent to actuate the discs. This may be positive and reaches 6%. The Rosenblat viscous pump flow is used to predict the power spent for disc motion in the turbulent channel flow and to estimate localized and transient regions over the disc surface subjected to the turbulent regenerative braking effect, for which the wall turbulence exerts work on the discs. The...

  18. Complications corner: Anterior thoracic disc surgery with dural tear/CSF fistula and low-pressure pleural drain led to severe intracranial hypotension

    PubMed Central

    Oudeman, Eline A.; Tewarie, Rishi D. S. Nandoe; Jöbsis, G. Joost; Arts, Mark P.; Kruyt, Nyika D.

    2015-01-01

    Background: Thoracic disc surgery can lead to a life-threatening complication: intracranial hypotension due to a subarachnoid-pleural fistula. Case Description: We report a 63-year-old male with paraparesis due to multiple herniated thoracic discs, with compressive myelopathy. The patient required a circumferential procedure including a laminectomy/fusion followed by an anterior thoracic decompression to address both diffuse idiopathic skeletal hyperostosis (DISH) anteriorly and posterior stenosis. The postoperative course was complicated by severe intracranial hypotension attributed to the erroneous placement of a low-pressure drain placed in the pleural cavity instead of a lumbar drain; this resulted in subdural hematoma's necessitating subsequent surgery. Conclusion: Severe neurological deterioration occurring after thoracic decompressive surgery may rarely be attributed to intracranial hypotension due to a subarachnoid-pleural fistula. Patients should be treated with external lumbar drainage of cerebrospinal fluid for 3–5 days rather than a low-pressure pleural drain to avoid the onset of intracranial hypotension leading to symptomatic subdural hematomas. PMID:26005575

  19. Vacuum Energy: Myths and Reality

    Microsoft Academic Search

    2006-01-01

    We discuss the main myths related to the vacuum energy and cosmological\\u000aconstant, such as: ``unbearable lightness of space-time''; the dominating\\u000acontribution of zero point energy of quantum fields to the vacuum energy;\\u000anon-zero vacuum energy of the false vacuum; dependence of the vacuum energy on\\u000athe overall shift of energy; the absolute value of energy only has significance\\u000afor

  20. Stellarator helical vacuum vessel

    SciTech Connect

    Yavornik, E.J.

    1983-01-01

    A design study of a stainless steel, heavy wall, helically shaped vacuum torus has been made for use in a proposed Stellarator configuration. The study concerns itself with the shape of the vacuum vessel and the division of the vessel into components that can be machined and welded together into a helical configuration. A complication in the design requires that a circular magnet coil be located at the minor toroidal axis and that this coil be embedded within the periphery of the vacuum vessel. The vacuum vessel has a minor toroidal axis diameter of 4 meters, a 68.6-cm shell diameter, and a 1.9-cm wall thickness. It twists about the minor toroidal axis twice in 360/sup 0/C. (An n value of 2). It is proposed that the unit be made of cylindrical segments with the ends of the cylinders cut at appropriate lengths and angles to form the helix. A mathematical derivation of the dimensions necessary to produce the required shapes of the segments has been made. Also, drawings of the vacuum vessel components have been produced on LANL's CTR CAD/CAM system. The procedure developed can be used for any value of n as dictated by physics requirements.

  1. Vacuum Techniques Lecture Notes

    NSDL National Science Digital Library

    Most modern day experimental research in physical chemistry is performed with the use of some sort of vacuum system. Organic and inorganic chemists are also finding it is essential to conduct synthetic and kinetic work under controlled or reduced pressures. The term "vacuum system" is applied rather broadly, from instrumentation that operates at very low pressures (i.e., below 10-8 torr) to systems that are only pumped down once to remove air and then used to handle gases at moderate pressures (up to and sometimes over one atmosphere). Vacuum systems vary widely in their size and complexity (and expense) depending on the requirements of pumping speed and attainable vacuum. This experiment is designed to illustrate the purpose and use of the basic components found on typical vacuum apparati. The volumes of the isolatable sections of the system will be measured. Also, some of the variables, such as pumping speed, which should be considered in designing such a system, will be investigated.

  2. Assessing the Effect of Spaceflight on the Propensity for Astronauts to Develop Disk Herniation

    NASA Technical Reports Server (NTRS)

    Feiveson, A. H.; Mendez, C. M.; Somers, J. T.

    2014-01-01

    BACKGROUND: A previous study [1] reported that the instantaneous risk of developing a Herniated Nucleus Pulposus (HNP) was higher in astronauts who had flown at least one mission, as compared with those in the corps who had not yet flown. However, the study only analyzed time to HNP after the first mission (if any) and did not account for the possible effects of multiple missions. While many HNP's occurred well into astronauts' careers or in some cases years after retirement, the higher incidence of HNPs relatively soon after completion of space missions appears to indicate that spaceflight may lead to an increased risk of HNP. The purpose of this study was to support the Human System Risk Board assessment of back pain, evaluate the risk of injury due to dynamic loads, and update the previous dataset which contained events up to December 31, 2006. METHODS: Data was queried from the electronic medical record and provided by the Lifetime Surveillance of Astronaut Health. The data included all 330 United States astronauts from 1959 through February 2014. Cases were confirmed by Magnetic Resonance Imaging, Computerized Tomography, Myelography, operative findings, or through clinical confirmation with a neurologist or neurosurgeon. In this analysis, astronauts who had an HNP at selection into the corps or had an HNP diagnosis prior to their first flight were excluded. The statistical challenges in using the available data to separate effects of spaceflight from those associated with general astronaut training and lifestyle on propensity to develop HNPs are many. The primary outcome is reported date of first HNP (if any), which at best is only an approximation to the actual time of occurrence. To properly analyze this data with a survival analysis model, one must also know the "exposure" time - i.e. how long each astronaut has been at risk for developing an HNP. If an HNP is reported soon after a mission, is it mission caused or general? If the former, exposure time should be counted from the time of landing (assuming the risk of HNP occurring during a mission is zero). If the latter, exposure time should be counted from the time of selection; however we can't directly know which one to use. In our analysis we take both of these possibilities into account with a competing risks model, wherein two distinct stochastic processes are going on: TG = time to HNP (general) and TS = time to HNP (spaceflight). Under this type of model, whichever of these occurs first is what we observe; in other words we don't observe TG or TS, only min(TG, TS). Here, we parameterized the model in terms of separate Weibull hazard functions for each process and estimated all parameters using maximum likelihood. In addition, we allowed for a "cured fraction" - i.e. the possibility that some astronauts may never develop an HNP. RESULTS: Results will include a depiction of the competing hazard functions as well as a probability curve for the relative likelihood that an HNP reported at a given time after a mission is actually mission caused. Other factors, such as dwell time in microgravity and vehicle landing environment will be explored. An overall assessment as to whether spaceflight truly exacerbates HNP risk will be made.

  3. Preparation of ormetoprim-sulfadimethoxine-medicated discs for disc diffusion assay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Romet ( a blend of ormetoprim and sulfadimethoxine) is a type A medicated article for the manufacture of medicated feed in the catfish industry. Recently, the commercial manufacture of ormetoprim-sulfadimethoxine susceptibility discs was discontinued. Ormetoprim-sulfadimethoxine discs were prepare...

  4. Modeling and optimization of an elastic arthroplastic disc for a degenerated disc

    NASA Astrophysics Data System (ADS)

    Ghouchani, Azadeh; Ravari, Mohammad; Mahmoudi, Farid

    2011-10-01

    A three-dimensional finite element model (FEM) of the L3-L4 motion segment using ABAQUS v 6.9 has been developed. The model took into account the material nonlinearities and is imposed different loading conditions. In this study, we validated the model by comparison of its predictions with several sets of experimental data. Disc deformation under compression and segmental rotational motions under moment loads for the normal disc model agreed well with the corresponding in vivo studies. By linking ABAQUS with MATLAB 2010.a, we determined the optimal Young s modulus as well as the Poisson's ratio for the artificial disc under different physiologic loading conditions. The results of the present study confirmed that a well-designed elastic arthroplastic disc preferably has an annulus modulus of 19.1 MPa and 1.24 MPa for nucleus section and Poisson ratio of 0.41 and 0.47 respectively. Elastic artificial disc with such properties can then achieve the goal of restoring the disc height and mechanical function of intact disc under different loading conditions and so can reduce low back pain which is mostly caused due to disc degeneration.

  5. Reappraisal of the ratio of disc to macula\\/disc diameter in optic nerve hypoplasia

    Microsoft Academic Search

    S M Zeki; J Dudgeon; G N Dutton

    1991-01-01

    The ratio of disc to macula\\/disc diameter is characteristically increased in eyes with optic nerve hypoplasia. We present the largest reported series of patients with a definitive diagnosis of optic nerve hypoplasia for whom this ratio has been determined. All measurements were made by an independent masked observer. Our results are in accordance with previous reports. A ratio of 2.94

  6. Heidelberg Retina Tomograph Disc Area: Correlation with Glaucoma Severity, Using the Disc Damage Likelihood Scale

    Microsoft Academic Search

    Paul Harasymowycz; Gang Xu; Jonathan Myers; William Steinmann; George L. Spaeth

    Purpose: To determine the correlation of Heidelberg Retina Tomograph disc area (HRT DA) to glaucoma severity, and how the severity of glaucoma may influence this relationship. Definition: The Disc Damage Likelihood Scale (DDLS) is a method of estimating the amount of optic nerve damage based on the width of the neuroretinal rim or the circum- ferential extent of rim absence.

  7. Improving Vacuum Cleaners

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Under a Space Act Agreement between the Kirby company and Lewis Research Center, NASA technology was applied to a commercial vacuum cleaner product line. Kirby engineers were interested in advanced operational concepts, such as particle flow behavior and vibration, critical factors to improve vacuum cleaner performance. An evaluation of the company 1994 home care system, the Kirby G4, led to the refinement of the new G5 and future models. Under the cooperative agreement, Kirby had access to Lewis' holography equipment, which added insight into how long a vacuum cleaner fan would perform, as well as advanced computer software that can simulate the flow of air through fans. The collaboration resulted in several successes including fan blade redesign and continuing dialogue on how to improve air-flow traits in various nozzle designs.

  8. Reconstructing the star formation history of the Milky Way disc(s) from chemical abundances

    NASA Astrophysics Data System (ADS)

    Snaith, O.; Haywood, M.; Di Matteo, P.; Lehnert, M. D.; Combes, F.; Katz, D.; Gómez, A.

    2015-06-01

    We develop a chemical evolution model to study the star formation history of the Milky Way. Our model assumes that the Milky Way has formed from a closed-box-like system in the inner regions, while the outer parts of the disc have experienced some accretion. Unlike the usual procedure, we do not fix the star formation prescription (e.g. Kennicutt law) to reproduce the chemical abundance trends. Instead, we fit the abundance trends with age to recover the star formation history of the Galaxy. Our method enables us to recover the star formation history of the Milky Way in the first Gyrs with unprecedented accuracy in the inner (R < 7-8 kpc) and outer (R > 9-10 kpc) discs, as sampled in the solar vicinity. We show that half the stellar mass formed during the thick-disc phase in the inner galaxy during the first 4-5 Gyr. This phase was followed by a significant dip in star formation activity (at 8-9 Gyr) and a period of roughly constant lower-level star formation for the remaining 8 Gyr. The thick-disc phase has produced as many metals in 4 Gyr as the thin-disc phase in the remaining 8 Gyr. Our results suggest that a closed-box model is able to fit all the available constraints in the inner disc. A closed-box system is qualitatively equivalent to a regime where the accretion rate maintains a high gas fraction in the inner disc at high redshift. In these conditions the SFR is mainly governed by the high turbulence of the interstellar medium. By z ~ 1 it is possible that most of the accretion takes place in the outer disc, while the star formation activity in the inner disc is mostly sustained by the gas that is not consumed during the thick-disc phase and the continuous ejecta from earlier generations of stars. The outer disc follows a star formation history very similar to that of the inner disc, although initiated at z ~ 2, about 2 Gyr before the onset of the thin-disc formation in the inner disc.

  9. The automatic detection of the optic disc location in retinal images using optic disc location regression.

    PubMed

    Abràmoff, Michael D; Niemeijer, Meindert

    2006-01-01

    The automatic detection of the position of the optic disc is an important step in the automatic analysis of retinal images. A method to detect the approximate position of the optic disc using kNN regression is presented. The method starts by building a regression model of the optic disc position. Using a prior vessel segmentation all vessel pixels are searched for those which are inside the optic disc according to the regression model. The regression output is blurred to handle noise. The point which is closest to the middle of the optic disc is chosen. The method was tested on 1000 screening images and was able to find the correct position in 99.9% of all cases. PMID:17947087

  10. Reoperations Following Cervical Disc Replacement

    PubMed Central

    Skovrlj, Branko; Lee, Dong-Ho; Caridi, John Michael

    2015-01-01

    Cervical disc replacement (CDR) has emerged as an alternative surgical option to cervical arthrodesis. With increasing numbers of patients and longer follow-ups, complications related to the device and/or aging spine are growing, leaving us with a new challenge in the management and surgical revision of CDR. The purpose of this study is to review the current literature regarding reoperations following CDR and to discuss about the approaches and solutions for the current and future potential complications associated with CDR. The published rates of reoperation (mean, 1.0%; range, 0%-3.1%), revision (mean, 0.2%; range, 0%-0.5%), and removal (mean, 1.2%; range, 0%-1.9%) following CDR are low and comparable to the published rates of reoperation (mean, 1.7%; range; 0%-3.4%), revision (mean, 1.5%; range, 0%-4.7%), and removal (mean, 2.0%; range, 0%-3.4%) following cervical arthrodesis. The surgical interventions following CDR range from the repositioning to explantation followed by fusion or the reimplantation to posterior foraminotomy or fusion. Strict patient selection, careful preoperative radiographic review and surgical planning, as well as surgical technique may reduce adverse events and the need for future intervention. Minimal literature and no guidelines exist for the approaches and techniques in revision and for the removal of implants following CDR. Adherence to strict indications and precise surgical technique may reduce the number of reoperations, revisions, and removals following CDR. Long-term follow-up studies are needed, assessing the implant survivorship and its effect on the revision and removal rates.

  11. Vacuum Arc Ion Sources

    E-print Network

    Brown, I

    2013-01-01

    The vacuum arc ion source has evolved into a more or less standard laboratory tool for the production of high-current beams of metal ions, and is now used in a number of different embodiments at many laboratories around the world. Applications include primarily ion implantation for material surface modification research, and good performance has been obtained for the injection of high-current beams of heavy-metal ions, in particular uranium, into particle accelerators. As the use of the source has grown, so also have the operational characteristics been improved in a variety of different ways. Here we review the principles, design, and performance of vacuum arc ion sources.

  12. Spacecraft thermal vacuum testing

    NASA Technical Reports Server (NTRS)

    Elam, B. F.; Lancaster, L. D.

    1972-01-01

    An approach for developing a general thermal vacuum test program philosophy is discussed. Guidelines are established that will assist the project engineer in relating the risk associated with flying any spacecraft to its test program. Computerized techniques can be used to help ascertain these guidelines, which relate the risk to the level of test (component, subsystem, etc), as well as to the type of test (development, qualification, etc). The interrelationship between the test program and the analytical effort is also discussed. The Skylab Apollo telescope mount general thermal vacuum test program, including test schedules, instrumentation, and test results is also discussed.

  13. K-130 Cyclotron vacuum system

    NASA Astrophysics Data System (ADS)

    Yadav, R. C.; Bhattacharya, S.; Bhole, R. B.; Roy, Anindya; Pal, Sarbajit; Mallik, C.; Bhandari, R. K.

    2012-11-01

    The vacuum system for K-130 cyclotron has been operational since 1977. It consists of two sub-systems, main vacuum system and beam line vacuum system. The main vacuum system is designed to achieve and maintain vacuum of about 1 × 10-6 mbar inside the 23 m3 volume of acceleration chamber comprising the Resonator tank and the Dee tank. The beam line vacuum system is required for transporting the extracted beam with minimum loss. These vacuum systems consist of diffusion pumps backed by mechanical pumps like roots and rotary pumps. The large vacuum pumps and valves of the cyclotron vacuum system were operational for more than twenty five years. In recent times, problems of frequent failures and maintenance were occurring due to aging and lack of appropriate spares. Hence, modernisation of the vacuum systems was taken up in order to ensure a stable high voltage for radio frequency system and the extraction system. This is required for efficient acceleration and transportation of high intensity ion beam. The vacuum systems have been upgraded by replacing several pumps, valves, gauges and freon units. The relay based control system for main vacuum system has also been replaced by PLC based state of the art control system. The upgraded control system enables inclusion of additional operational logics and safety interlocks into the system. The paper presents the details of the vacuum system and describes the modifications carried out for improving the performance and reliability of the vacuum system.

  14. The vacuum interpretation of quantum mechanics and the vacuum universe

    E-print Network

    Ding-Yu Chung

    2001-10-27

    Quantum mechanics is interpreted by the adjacent vacuum that behaves as a virtual particle to be absorbed and emitted by its matter. As described in the vacuum universe model, the adjacent vacuum is derived from the pre-inflationary universe in which the pre-adjacent vacuum is absorbed by the pre-matter. This absorbed pre-adjacent vacuum is emitted to become the added space for the inflation in the inflationary universe whose space-time is separated from the pre-inflationary universe. This added space is the adjacent vacuum. The absorption of the adjacent vacuum as the added space results in the adjacent zero space (no space), Quantum mechanics is the interaction between matter and the three different types of vacuum: the adjacent vacuum, the adjacent zero space, and the empty space. The absorption of the adjacent vacuum results in the empty space superimposed with the adjacent zero space, confining the matter in the form of particle. When the absorbed vacuum is emitted, the adjacent vacuum can be anywhere instantly in the empty space superimposed with the adjacent zero space where any point can be the starting point (zero point) of space-time. Consequently, the matter that expands into the adjacent vacuum has the probability to be anywhere instantly in the form of wavefunction. In the vacuum universe model, the universe not only gains its existence from the vacuum but also fattens itself with the vacuum. During the inflation, the adjacent vacuum also generates the periodic table of elementary particles to account for all elementary particles and their masses in a good agreement with the observed values.

  15. The vacuum conservation theorem

    E-print Network

    E. Minguzzi

    2015-02-28

    A version of the vacuum conservation theorem is proved which does not assume the existence of a time function nor demands stronger properties than the dominant energy condition. However, it is shown that a stronger stable version plays a role in the study of compact Cauchy horizons.

  16. Langmuir vacuum and superconductivity

    SciTech Connect

    Veklenko, B. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2012-06-15

    It is shown that, in the 'jelly' model of cold electron-ion plasma, the interaction between electrons and the quantum electromagnetic vacuum of Langmuir waves involves plasma superconductivity with an energy gap proportional to the energy of the Langmuir quantum.

  17. Vacuum insulator coating development

    Microsoft Academic Search

    I. S. Roth; P. S. Sincerny; L. Mandelcorn; M. Mendelsohn; D. Smith; T. G. Engel; L. Schlitt; C. M. Cooke

    1997-01-01

    The authors discuss the electrical and mechanical requirements for vacuum insulators in high peak power generators. To increase the lifetime of these insulators, they have developed a coating called Dendresist. This coating has extended the insulator lifetime on the PITHON, DM2, CASINO, and Double-EAGLE pulsed power generators. They describe its development, and compare its electrical and mechanical strength to that

  18. Vacuum Kundt waves

    NASA Astrophysics Data System (ADS)

    McNutt, David; Milson, Robert; Coley, Alan

    2013-03-01

    We discuss the invariant classification of vacuum Kundt waves using the Cartan-Karlhede algorithm and determine the upper bound on the number of iterations of the Karlhede algorithm to classify the vacuum Kundt waves (Collins (1991 Class. Quantum Grav. 8 1859-69), Machado Ramos (1996 Class. Quantum Grav. 13 1589)). By choosing a particular coordinate system we partially construct the canonical coframe used in the classification to study the functional dependence of the invariants arising at each iteration of the algorithm. We provide a new upper bound, q ? 4, and show that this bound is sharp by analyzing the subclass of Kundt waves with invariant count beginning with (0, 1,…) to show that the class with invariant count (0, 1, 3, 4, 4) exists. This class of vacuum Kundt waves is shown to be unique as the only set of metrics requiring the fourth covariant derivatives of the curvature. We conclude with an invariant classification of the vacuum Kundt waves using a suite of invariants.

  19. Safety of Minkowski Vacuum

    E-print Network

    Gia Dvali

    2011-07-05

    We give a simple argument suggesting that in a consistent quantum field theory tunneling from Minkowski to a lower energy vacuum must be impossible. Theories that allow for such a tunneling also allow for localized states of negative mass, and therefore, should be inconsistent.

  20. What is vacuum?

    Microsoft Academic Search

    Peter Rowlands

    2008-01-01

    Vacuum can be defined with exact mathematical precision as the state which remains when a fermion, with all its special characteristics, is created out of absolutely nothing. The definition leads to a special form of relativistic quantum mechanics, which only requires the construction of a creation operator. This form of quantum mechanics is especially powerful for analytic calculation, at the

  1. Vacuum Arc Anode Phenomena

    Microsoft Academic Search

    H. Craig Miller

    1977-01-01

    This paper presents a brief review of anode phenomena in vacuum arcs. It discusses in succession the transition of the arc into the anode spot mode; the temperature of the anode before, during, and after formation of an anode spot; and anode ions. Characteristically the anode spot has a temperature of the order of the atmospheric boiling point of the

  2. Vacuum arc recovery phenomena

    Microsoft Academic Search

    J. A. Rich; G. A. Farrall

    1964-01-01

    The present experimental and theoretical study has been designed to uncover the mechanism underlying the rapid recovery of electrical strength of a short vacuum gap after arcing. In the experiment the contacts were of gas-free silver and the contact area and gap length were varied. Recovery strength was measured following the forced extinction of a 250 amp arc in 0.5

  3. Vacuum arcs and switching

    Microsoft Academic Search

    G. A. Farrall

    1973-01-01

    This paper is a review of vacuum-arc phenomena which are related to switching devices. Despite the device overtones, the approach adopted for this paper is fundamental. Topics discussed include the drawn arc, the triggered arc, the power input to the cathode spot, cathode-spot division, arc stability, substructure of the cathode spot, dielectric recovery processes, and breakdown between electrodes subjected to

  4. Vacuum arc deposition devices

    SciTech Connect

    Boxman, R.L.; Zhitomirsky, V.N. [Electrical Discharge and Plasma Laboratory, Faculty of Engineering, Tel Aviv University, P.O. Box 39040, Tel Aviv 69978 (Israel)

    2006-02-15

    The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

  5. Nonlinear Oscillators Vacuum Squeezing

    E-print Network

    Haviland, David

    dz mtF dt dz mzzk =++ =+ --- Classical Physics: The Driven Damped Harmonic Oscillator - a modelNonlinear Oscillators and Vacuum Squeezing David Haviland Nanosturcture Physics, Dept. Applied #12;Splitting of Cavity Resonance Now consider damping: excitation is ½ photon, ½ atom decay rate: 2

  6. Decoherence and Vacuum Fluctuations

    Microsoft Academic Search

    L. H. Ford

    1995-01-01

    The interference pattern of coherent electrons is effected by coupling to the quantized electromagnetic field. The amplitudes of the interference maxima are changed by a factor which depends upon a double line integral of the photon two-point function around the closed path of the electrons. The interference pattern is sensitive to shifts in the vacuum fluctuations in regions from which

  7. Light-front vacuum

    NASA Astrophysics Data System (ADS)

    Herrmann, Marc; Polyzou, W. N.

    2015-04-01

    The purpose of this work is to understand the relation between the trivial vacuum in light-front field theory and the nontrivial vacuum in canonical representations of quantum field theory and the role of zero-modes in this relation. The role of the underlying field algebra in the definition of the vacuum is exploited to understand these relations. The trivial vacuum defined by an annihilation operator defines a linear functional on the algebra of fields restricted to a light front. This is extended to a linear functional on the algebra of local fields. The extension defines a unitary mapping between the physical representation of the local algebra and a sub-algebra of the light-front Fock algebra. The dynamics appears in the mapping and the structure of the sub-algebra. This correspondence provides a formulation of locality and Poincaré invariance on the light-front Fock space. Zero modes do not appear in the final mapping, but may be needed in the construction of the mapping using a local Lagrangian.

  8. The vacuum conservation theorem

    NASA Astrophysics Data System (ADS)

    Minguzzi, E.

    2015-03-01

    A version of the vacuum conservation theorem is proved which does not assume the existence of a time function nor demands stronger properties than the dominant energy condition. However, it is shown that a stronger stable version plays a role in the study of compact Cauchy horizons.

  9. The quantum vacuum

    E-print Network

    Paraoanu, G S

    2014-01-01

    The vacuum is the lowest energy state of a field in a certain region of space. This definition implies that no particles can be present in the vacuum state. In classical physics, the only features of vacuum are those of its geometry. For example, in the general theory of relativity the geometry is a dynamical structure that guides the motion of matter, and, in turn, it is bent and curved by the presence of matter. Other than this, the classical vacuum is a structure void of any physical properties, since classically properties are strictly associated with physical objects such as particles and finite-amplitude fields. The situation is very different in quantum physics. As I will show in this paper, the difference stems form the fact that in quantum physics the properties are not strictly tied to objects. We know for example that physical properties come into existence - as values of observables - only when the object is measured. Thus, quantum physics allows us to detach properties from objects. This has cons...

  10. Vacuum configurations for superstrings

    Microsoft Academic Search

    P. Candelas; Gary T. Horowitz; Andrew Strominger; Edward Witten

    1985-01-01

    We study candidate vacuum configurations in ten-dimensional O(32) and E8 × E8 supergravity and superstring theory that have unbroken N = 1 supersymmetry in four dimensions. This condition permits only a few possibilities, all of which have vanishing cosmological constant. In the E8 × E8 case, one of these possibilities leads to a model that in four dimensions has an

  11. A general model for vacuum condensates and vacuum diffusive coatings

    Microsoft Academic Search

    RI Shishkov; EM Lisichkova

    1995-01-01

    The paper suggests a general model for the classification of metal coatings obtained in vacuum. The model gives the thickness, the bond character and the bond to the coated substrate, depending on : temperature, forming time and condensation rate. The coatings have been classified in two basic groups : vacuum condensates and vacuum diffusive coatings, separated by a layer zone

  12. Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.

    ERIC Educational Resources Information Center

    Greenslade, Thomas B., Jr.

    1989-01-01

    Explains mechanisms of 19th-century vacuum pumps. Describes demonstrations using the pump including guinea and feather tube, aurora tube, electric egg, Gassiots cascade, air mill, bell in vacuum, density and buoyancy of air, fountain in vacuum, mercury shower, palm and bladder glasses, Bacchus demonstration, pneumatic man-lifter, and Magdeburg…

  13. Warped and eccentric discs around black holes

    E-print Network

    Gordon I. Ogilvie; Barbara T. Ferreira

    2008-10-01

    Accretion discs around black holes in X-ray binary stars are warped if the spin axis of the black hole is not perpendicular to the binary orbital plane. They can also become eccentric through an instability involving a resonance with the binary orbit. Depending on the thickness of the disc and the efficiency of dissipative processes, these global deformations may be able to propagate into the innermost part of the disc in the form of stationary bending or density waves. We describe the solutions in the linear regime and discuss the conditions under which a warp or eccentricity is likely to produce significant activity in the inner region, which may include the excitation of quasi-periodic oscillations.

  14. Adolescent disc dysplasia and back pain

    PubMed Central

    Anakwenze, Okechukwu A.; Kancherla, Vamsi; Rendon, Norma

    2010-01-01

    Purpose Adolescent disc dysplasia can be a cause of significant back pain and functional impairment in patients. We present a case series of patients inflicted with adolescent disc dysplasia (ADD). Methods A retrospective search was performed identifying patients presenting with ADD. Radiographic studies and advanced imaging were described. We documented presenting symptoms and clinical course. Results Six patients were identified. All patients presented with mechanical back pain, which worsened with flexion and extension. Magnetic resonance imaging was most accurate imaging modality. Conclusion Among our patient cohort, treatment for adolescent disc dysplasia consisted of a combination of physical therapy and bracing. Neither approach proved to be very effective, with only one patient asymptomatic at follow-up. PMID:22295049

  15. Vertical oscillations of fluid and stellar discs

    NASA Astrophysics Data System (ADS)

    Widrow, Lawrence M.; Bonner, Gage

    2015-06-01

    A satellite galaxy or dark matter subhalo that passes through a stellar disc may excite coherent oscillations in the disc perpendicular to its plane. We determine the properties of these modes for various self-gravitating plane symmetric systems (Spitzer sheets) using the matrix method of Kalnajs. In particular, we find an infinite series of modes for the case of a barotropic fluid. In general, for a collisionless system, there is a double series of modes, which include normal modes and/or Landau-damped oscillations depending on the phase space distribution function of the stars. Even Landau-damped oscillations may decay slowly enough to persist for several hundred Myr. We discuss the implications of these results for the recently discovered vertical perturbations in the kinematics of solar neighbourhood stars and for broader questions surrounding secular phenomena such as spiral structure in disc galaxies.

  16. Cerebrovascular bypass and aneurysm trapping for the treatment of an A2-segment anterior cerebral artery pseudoaneurysm and herniation through a skull base defect following trauma.

    PubMed

    Walcott, Brian P; Nahed, Brian V; Kahle, Kristopher T; Sekhar, Laligam N; Ferreira, Manuel J

    2012-01-01

    Fractures of the anterior skull base can lead to pseudoaneurysm formation as a result of direct injury to a vessel wall. Pseudoaneurysms in this location are challenging to treat, as both perforator and distal blood supply must be maintained. Additionally, traumatic skull base fractures can lead to a rare condition of cerebral blood vessel herniation through the bony defect, further complicating treatment planning. Treatment of these lesions is essential to (1) prevent the occurrence of potentially fatal subarachnoid hemorrhage and (2) prevent dissection from propagating and compromising blood flow to distal vessels, perforators, and even parent vessels. We present a unique case of a traumatic proximal anterior cerebral artery pseudoaneurysm, herniating through a skull base defect. Treatment consisted of aneurysm trapping and bypass with skull base reconstruction. PMID:22051032

  17. Appearance of Keplerian discs orbiting Kerr superspinars

    NASA Astrophysics Data System (ADS)

    Stuchlík, Zden?k; Schee, Jan

    2010-11-01

    We study optical phenomena related to the appearance of Keplerian accretion discs orbiting Kerr superspinars predicted by string theory. The superspinar exterior is described by standard Kerr naked singularity geometry breaking the black hole limit on the internal angular momentum (spin). We construct local photon escape cones for a variety of orbiting sources that enable us to determine the superspinars silhouette in the case of distant observers. We show that the superspinar silhouette depends strongly on the assumed edge where the external Kerr spacetime is joined to the internal spacetime governed by string theory and significantly differs from the black hole silhouette. The appearance of the accretion disc is strongly dependent on the value of the superspinar spin in both their shape and frequency shift profile. Apparent extension of the disc grows significantly with the growing spin, while the frequency shift grows with the descending spin. This behaviour differs substantially from the appearance of discs orbiting black holes enabling thus, at least in principle, to distinguish clearly the Kerr superspinars and black holes. In vicinity of a Kerr superspinar the non-escaped photons have to be separated to those captured by the superspinar and those being trapped in its strong gravitational field leading to self-illumination of the disc that could even influence its structure and cause self-reflection effect of radiation of the disc. The amount of trapped photons grows with descending superspinar spin. We thus can expect significant self-illumination effects in the field of Kerr superspinars with near-extreme spin a ~ 1.

  18. Tritium handling in vacuum systems

    SciTech Connect

    Gill, J.T. [Monsanto Research Corp., Miamisburg, OH (United States). Mound Facility; Coffin, D.O. [Los Alamos National Lab., NM (United States)

    1986-10-01

    This report provides a course in Tritium handling in vacuum systems. Topics presented are: Properties of Tritium; Tritium compatibility of materials; Tritium-compatible vacuum equipment; and Tritium waste treatment.

  19. Furnace brazing under partial vacuum

    NASA Technical Reports Server (NTRS)

    Mckown, R. D.

    1979-01-01

    Brazing furnace utilizing partial-vacuum technique reduces tooling requirements and produces better bond. Benefit in that partial vacuum helps to dissociate metal oxides that inhibit metal flow and eliminates heavy tooling required to hold parts together during brazing.

  20. A microvascular surgical practice disc for beginners.

    PubMed

    Lee, S; Coppersmith, W J

    1983-01-01

    In order to assist beginners in microsurgery in practicing microvascular suturing without the use of an animal model, we devised an apparatus composed of a Lucite disc with Lucite cylinders attached to either side. On the one side, a piece of rubber glove can be attached for practice of either continuous or interrupted suturing. On the other side, four slots in the cylinder permit suture material or simulated blood vessel to be placed and held for practice in tying knots or end-to-end anastomosis. The disc apparatus is very inexpensive, durable, and easily obtained. PMID:6355753

  1. Difficult to process? Vacuum it!

    SciTech Connect

    Eckles, A.J. [Atlanta Technology Group, GA (United States)

    1997-09-01

    Recent improvements in vacuum processing have broadened the technology`s use in the chemical process industries, running the gamut from vacuum distillation and evaporation, degassing, freeze drying, vapor deposition and etching, to vacuum filtrations. The paper discusses process improvements, attaining liquid distribution, medium-vacuum processing, falling-film evaporators, wiped-film evaporators, short-path evaporators, evaporation and crystallization, filtration, drying, refrigeration, freeze drying, degassing, semiconductor processing, pumps and their selection, and leak testing.

  2. A radiation hard vacuum switch

    DOEpatents

    Boettcher, G.E.

    1988-07-19

    A vacuum switch with an isolated trigger probe which is not directly connected to the switching electrodes. The vacuum switch within the plasmatron is triggered by plasma expansion initiated by the trigger probe which travels through an opening to reach the vacuum switch elements. The plasma arc created is directed by the opening to the space between the anode and cathode of the vacuum switch to cause conduction. 3 figs.

  3. Intervertebral disc degeneration: evidence for two distinct phenotypes

    PubMed Central

    Adams, Michael A; Dolan, Patricia

    2012-01-01

    We review the evidence that there are two types of disc degeneration. ‘Endplate-driven’ disc degeneration involves endplate defects and inwards collapse of the annulus, has a high heritability, mostly affects discs in the upper lumbar and thoracic spine, often starts to develop before age 30 years, usually leads to moderate back pain, and is associated with compressive injuries such as a fall on the buttocks. ‘Annulus-driven’ disc degeneration involves a radial fissure and/or a disc prolapse, has a low heritability, mostly affects discs in the lower lumbar spine, develops progressively after age 30 years, usually leads to severe back pain and sciatica, and is associated with repetitive bending and lifting. The structural defects which initiate the two processes both act to decompress the disc nucleus, making it less likely that the other defect could occur subsequently, and in this sense the two disc degeneration phenotypes can be viewed as distinct. PMID:22881295

  4. Clinical measurement and categorization of optic disc in glaucoma patients

    PubMed Central

    Rao, Harsha B L; Sekhar, G C; Babu, Ganesh J; Parikh, Rajul S

    2009-01-01

    Background: Assessment of optic disc size is an important component of optic nerve head examination. Agreement between different methods of disc size measurements is not very good. Purpose: To assess the agreement between the disc size assessed by Heidelberg retina tomograph (HRT) and stereobiomicroscopy with a 90 diopter (D) lens. To report the clinical (measured by biomicroscopy) disc diameters of small, average and large optic discs categorized by HRT disc areas. Setting and Design: Observational study of subjects examined in the glaucoma clinic of a tertiary eye institute. Materials and Methods: Seventy-five eyes of 75 glaucoma subjects were studied. Disc diameter was measured using stereobiomicroscopy and HRT. The agreement between the two sets of measurements was assessed by intraclass correlation coefficient (ICC). Discs were classified into small (<1.6 mm2), average (1.6-2.6 mm2) and large (>2.6 mm2) depending on cutoffs provided by the manufacturers of HRT. The means (95% CI) of the corresponding vertical disc diameter in these groups were assessed. Statistical Analysis: ICC, Bland and Altman plots. Results: ICC for measurements of clinical and HRT horizontal disc diameter was 0.518 and for vertical disc diameter measurement was 0.487. The mean difference between the clinical and HRT measurements as analyzed by the Bland and Altman plot was 0.17 (95% CI, 0.13- 0.47) for horizontal and 0.22 (95% CI, 0.11- 0.54) for vertical disc diameter. Of the 75 eyes, 3 eyes had small discs, 54 average and 18 large discs. The mean clinical vertical disc diameter for small discs was 1.55 mm (95% CI, 1.2-1.7), for average discs was 1.91 mm (95% CI, 1.87-1.96) and for large discs was 2.15 mm (95% CI, 2.03–2.27). Conclusion: The agreement between clinical and HRT disc diameter measurements is moderate. Disc diameter measurement on stereobiomicroscopy can be used to categorize discs into small, average and large discs. PMID:19700874

  5. Vacuum Energy: Myths and Reality

    E-print Network

    G. E. Volovik

    2006-07-10

    We discuss the main myths related to the vacuum energy and cosmological constant, such as: ``unbearable lightness of space-time''; the dominating contribution of zero point energy of quantum fields to the vacuum energy; non-zero vacuum energy of the false vacuum; dependence of the vacuum energy on the overall shift of energy; the absolute value of energy only has significance for gravity; the vacuum energy depends on the vacuum content; cosmological constant changes after the phase transition; zero-point energy of the vacuum between the plates in Casimir effect must gravitate, that is why the zero-point energy in the vacuum outside the plates must also gravitate; etc. All these and some other conjectures appear to be wrong when one considers the thermodynamics of the ground state of the quantum many-body system, which mimics macroscopic thermodynamics of quantum vacuum. In particular, in spite of the ultraviolet divergence of the zero-point energy, the natural value of the vacuum energy is comparable with the observed dark energy. That is why the vacuum energy is the plausible candidate for the dark energy.

  6. Compact Disc Recordable with Substrate of Biomass Plastic Material

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Atsushi; Kodama, Yasuhiro; Matsuo, Hiroto; Ohno, Minoru; Osugi, Satomi; Maeno, Yoshiaki; Higuchi, Masahiro

    2006-08-01

    Polylactic acid (PLA) is a biomass material made of starch. Compact disc recordable (CD-R) discs with a PLA substrate were prepared and their properties were measured. Although the glass transition point of PLA is lower than that of polycarbonate (PC), the PLA substrate is usable for CD-R discs. It was confirmed that the substrate is usable for recordable optical discs at temperatures under 50 °C.

  7. Compact vacuum insulation embodiments

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1992-04-28

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point' or line' contacts with the metal wall sheets. In the case of monolithic spacers that form line' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included. 26 figs.

  8. Vacuum tool manipulator

    DOEpatents

    Zollinger, W.T.

    1993-11-23

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm. 6 figures.

  9. Vacuum tool manipulator

    DOEpatents

    Zollinger, William T. (3927 Almon Dr., Martinez, GA 30907)

    1993-01-01

    Apparatus for manipulating a vacuum hose in a reactor vessel comprises a housing with two opposing openings, an arm carried by the housing and deployable from a stowed position essentially completely within the housing to an extended position where the arm extends through the two openings in a generally horizontal position. The arm preferably has a two-fingered gripping device for gripping the vacuum hose but may carry a different end effector such as a grinding wheel. The fingers are opened and closed by one air cylinder. A second air cylinder extends the device. A third air cylinder within the housing pivotally pulls the opposing end of the arm into the housing via a pivoting member pivotally connected between the third air cylinder shaft and the arm.

  10. Compact vacuum insulation

    DOEpatents

    Benson, D.K.; Potter, T.F.

    1993-01-05

    An ultra-thin compact vacuum insulation panel is comprised of two hard, but bendable metal wall sheets closely spaced apart from each other and welded around the edges to enclose a vacuum chamber. Glass or ceramic spacers hold the wall sheets apart. The spacers can be discrete spherical beads or monolithic sheets of glass or ceramic webs with nodules protruding therefrom to form essentially point'' or line'' contacts with the metal wall sheets. In the case of monolithic spacers that form line'' contacts, two such spacers with the line contacts running perpendicular to each other form effectively point'' contacts at the intersections. Corrugations accommodate bending and expansion, tubular insulated pipes and conduits, and preferred applications are also included.

  11. Automatic Optic Disc Boundary Extraction from Color Fundus Images

    Microsoft Academic Search

    Thresiamma Devasia; Paulose Jacob; Tessamma Thomas

    2014-01-01

    Efficient optic disc segmentation is an important task in automated retinal screening. For the same reason optic disc detection is fundamental for medical references and is important for the retinal image analysis application. The most difficult problem of optic disc extraction is to locate the region of interest. More over it is a time consuming task. This paper tries to

  12. Robust Optic Disc Location via Combination of Weak Detectors

    Microsoft Academic Search

    Adria Perez-Rovira; Emanuele Trucco

    2008-01-01

    This paper presents a new robust approach for the automatic location of the optic disc. We detect several candi- dates independently for optic disc, macula and the main blood vessels (arcades). Candidates are sorted by reliability. The space of all possible triplets disc-macula-arcades is searched using a- priori anatomical knowledge, selecting the triplet formed by the most reliable candidates satisfying

  13. Automatic optic disc segmentation with peripapillary atrophy elimination

    Microsoft Academic Search

    Jun Cheng; Jiang Liu; Damon Wing Kee Wong; Fengshou Yin; Carol Cheung; Mani Baskaran; Tin Aung; Tien Yin Wong

    2011-01-01

    Optic disc segmentation from retinal fundus image is a fundamental but important step for automatic glaucoma diagnosis. In this paper, an optic disc segmentation method is proposed based on peripapillary atrophy elimination. The elimination is done through edge filtering, constraint elliptical Hough transform and peripapillary atrophy detection. With the elimination, edges that are likely from non-disc structures especially peripapillary atrophy

  14. THE ULTRASTRUCTURE OF THE Z DISC IN SKELETAL MUSCLE

    Microsoft Academic Search

    G. G. KNAPPEIS; F. CARLSEN

    2010-01-01

    This electron microscopic study dcals with thc structure of thc Z disc of frog's skeletal musclc, with special rcgard to thc I filamcnts--whcthcr thcy pass through thc Z disc or terminate at it. In most longitudinal sections thc I filaments tcrminatc as rod-likc projections on cithcr sidc of the Z disc, one I filamcnt on onc side lying between two

  15. Influences of osteoporosis and disc degeneration on lumbar spinal stability

    Microsoft Academic Search

    2003-01-01

    Disc degeneration and osteoporosis are two main factors affecting the elderly and impacting the quality of life. The aims of this study were to provide the information on mechanical changes resulting from disc degeneration and osteoporosis and further to understand their roles in segmental instability. The influences of disc degeneration and osteoporosis were investigated using a 3?dimensional finite element model

  16. Spatially Varying Material Properties of the Rat Caudal Intervertebral Disc

    Microsoft Academic Search

    Mandy M. Ho; Terri-Ann N. Kelly; X. Edward Guo; Gerard A. Ateshian; Clark T. Hung

    2006-01-01

    Study Design. The use of a microscopy based material testing technique to assess the local material properties of rat caudal intervertebral discs under uniaxial compression. Objectives. To better understand the cell environment of rat caudal intervertebral discs during mechanical load- ing and elucidate better the role of the nucleus pulposus to the overall disc material properties. Summary of Background Data.

  17. Biomechanical comparison between lumbar disc arthroplasty and fusion

    Microsoft Academic Search

    Shih-Hao Chen; Zheng-Cheng Zhong; Chen-Sheng Chen; Wen-Jer Chen; Chinghua Hung

    2009-01-01

    The artificial disc is a mobile implant for degenerative disc replacement that attempts to lessen the degeneration of the adjacent elements. However, inconsistent biomechanical results for the neighboring elements have been reported in a number of studies. The present study used finite element (FE) analysis to explore the biomechanical differences at the surgical and both adjacent levels following artificial disc

  18. The Effects of Simulated Microgravity on Intervertebral Disc Degeneration

    PubMed Central

    Jin, Li; Feng, Gang; Reames, Davis L; Shimer, Adam L; Shen, Francis H; Li, Xudong

    2012-01-01

    BACKGROUND CONTEXT Astronauts experience back pain, particularly low back pain, during and after spaceflight. Recent studies have described histological and biochemical changes in rat intervertebral discs after space travel, but there is still no in vitro model to investigate the effects of microgravity on disc metabolism. PURPOSE To study the effects of microgravity on disc degeneration and to establish an in vitro simulated microgravity study model STUDY DESIGN Discs were cultured in static and rotating conditions in bioreactor, and the characteristics of disc degeneration were evaluated METHODS The mice discs were cultured in a rotating wall vessel bioreactor where the microgravity condition was simulated. Intervertebral discs were cultured in static and microgravity condition. Histology, biochemistry, and immunohistochemical assays were performed to evaluate the characteristics of the discs in microgravity condition. RESULTS Intervertebral discs cultured in rotating bioreactors were found to develop changes of disc degeneration manifested by reduced red Safranin-o staining within the annulus fibrosus, downregulated GAG content and GAG/Hypro ratio, increased MMP-3 expression, and upregulated apoptosis. CONCLUSIONS We conclude that simulated microgravity induces the molecular changes of disc degeneration. The rotating bioreactor model will provide a foundation to investigate the effects of microgravity on disc metabolism. PMID:23537452

  19. MERRA Data Access and Stephen Berrick GES DISC, NASA GSFC

    E-print Network

    MERRA Data Access and Services Stephen Berrick GES DISC, NASA GSFC Dana Ostrenga GES DISC, NASA Center (GES DISC) is the archive for the MERRA data and provides a number of data access methods and data sensors, ground measurements, and models, including MERRA. These include Aqua AIRS, Aura HIRDLS

  20. Evaluation of Disc Brake Materials for Squeal Reduction

    Microsoft Academic Search

    J. Abdo; M. Nouby; D. Mathivanan; K. Srinivasan

    2011-01-01

    A nontraditional evaluation tool is introduced to examine the effects of different materials, in practical applications, which are used in fabricating disc brake components for commonly used or special requirements such as heavy duty performance and racing cars. As an extension to earlier FE disc brake models, a detailed FE model of the whole disc brake corner that incorporates wheel

  1. Clinical Analysis of Disc Battery Ingestion in Children

    Microsoft Academic Search

    Yi-Jung Chang; Hsun-Chin Chao; Man-Shan Kong; Ming-Wei Lai

    Background: The purpose of this study was to evaluate the characteristics, management, and outcomes of disc battery ingestion in children. Methods: We reviewed the medical records of children aged between 1 and 15 years old admitted to Chang Gung Children's Hospital due to disc battery ingestion from September 1997 through July 2003). The diagnosis of disc battery ingestion was based

  2. Interactive Optical Disc Systems: Part 1: Analog Storage.

    ERIC Educational Resources Information Center

    Hessler, David W.

    1984-01-01

    Details distinction between digital and analog data, advantages of analog storage, and optical disc use to store analog data. Configuration and potential of three levels of laser disc systems are explained. Selection of display devices for use with laser disc systems and accessing audio data are addressed. (Continued in next issue.) (EJS)

  3. Decoherence and Vacuum Fluctuations

    Microsoft Academic Search

    L. H. Ford

    1994-01-01

    The interference pattern of coherent electrons is effected by coupling to the\\u000aquantized electromagnetic field. The amplitudes of the interference maxima are\\u000achanged by a factor which depends upon a double line integral of the photon\\u000atwo-point function around the closed path of the electrons. The interference\\u000apattern is sensitive to shifts in the vacuum fluctuations in regions from which

  4. Decoherence and Vacuum Fluctuations

    E-print Network

    L. H. Ford

    1994-08-30

    The interference pattern of coherent electrons is effected by coupling to the quantized electromagnetic field. The amplitudes of the interference maxima are changed by a factor which depends upon a double line integral of the photon two-point function around the closed path of the electrons. The interference pattern is sensitive to shifts in the vacuum fluctuations in regions from which the electrons are excluded. Thus this effect combines aspects of both the Casimir and the Aharonov-Bohm effects. The coupling to the quantized electromagnetic field tends to decrease the amplitude of the interference oscillations, and hence is a form of decoherence. The contributions due to photon emission and to vacuum fluctuations may be separately identified. It is to be expected that photon emission leads to decoherence, as it can reveal which path an electron takes. It is less obvious that vacuum fluctuations also can cause decoherence. What is directly observable is a shift in the fluctuations due, for example, to the presence of a conducting plate. In the case of electrons moving parallel to conducting boundaries, the dominant decohering influence is that of the vacuum fluctuations. The shift in the interference amplitudes can be of the order of a few percent, so experimental verification of this effect may be possible. The possibility of using this effect to probe the interior of matter, e.g., to determine the electrical conductivity of a rod by means of electrons encircling it is discussed. (Presented at the Conference on Fundamental Problems in Quantum Theory, University of Maryland, Baltimore County, June 18-22, 1994.)

  5. Vacuum Ultraviolet Detector

    NASA Astrophysics Data System (ADS)

    Shao, Chun-Lin; Tomita, Kazuhiro; Jimbo, Takashi; Umeno, Masayoshi; Hattori, Shuzo

    1985-02-01

    A new vacuum ultraviolet detector has been fabricated. A sample was made using a crystalline quartz plate on the surface of which a metal electrode was deposited. It has been experimentally established that the sample is sensitive to VUV radiation, and the external quantum efficiency is estimated to be higher than several percent. The new photodetector also has very good stability and should be a practicable new VUV photodetector.

  6. Decoherence and vacuum fluctuations

    E-print Network

    Ford, L H

    1994-01-01

    The interference pattern of coherent electrons is effected by coupling to the quantized electromagnetic field. The amplitudes of the interference maxima are changed by a factor which depends upon a double line integral of the photon two-point function around the closed path of the electrons. The interference pattern is sensitive to shifts in the vacuum fluctuations in regions from which the electrons are excluded. Thus this effect combines aspects of both the Casimir and the Aharonov-Bohm effects. The coupling to the quantized electromagnetic field tends to decrease the amplitude of the interference oscillations, and hence is a form of decoherence. The contributions due to photon emission and to vacuum fluctuations may be separately identified. It is to be expected that photon emission leads to decoherence, as it can reveal which path an electron takes. It is less obvious that vacuum fluctuations also can cause decoherence. What is directly observable is a shift in the fluctuations due, for example, to the pr...

  7. Agreement in assessing optic discs with a digital stereoscopic optic disc camera (Discam) and Heidelberg retina tomograph

    Microsoft Academic Search

    Velota C T Sung; Anna Bhan; Stephen A Vernon

    2002-01-01

    Aims: To assess the intraobserver agreement, interobserver agreement, and the agreement between a digital stereo optic disc camera (Discam) and Heidelberg retina tomograph (HRT) in measuring area cup-disc ratio (ACDR) and radial cup-disc ratio (RCDR) by two observers.Methods: The optic discs of 78 eyes of 39 people (17 cases of primary open angle glaucoma, eight normal tension glaucoma, two ocular

  8. DISC-BASED IMMUNOASSAY MICROARRAYS. (R825433)

    EPA Science Inventory

    Microarray technology as applied to areas that include genomics, diagnostics, environmental, and drug discovery, is an interesting research topic for which different chip-based devices have been developed. As an alternative, we have explored the principle of compact disc-based...

  9. Infrared Variability from Circumbinary Disc Temperature Modulations

    E-print Network

    Bodman, Eva

    2015-01-01

    The temperature of a circumbinary disc edge should undulate due to variations in illumination as a function of binary orbital phase. We explore circumbinary disc temperature variations as a source of broad-band infrared light curve variability. Approximating the wall of a circumbinary disc edge as a wide optically thick cylinder with surface temperature dependent on its illumination, we find that a binary comprised of 1 M$_\\odot$ and 0.5 M$_\\odot$ pre-main sequence stars in a $\\sim$15.5 day period, would exhibit the largest amplitude variations of $\\sim$9% at 3.77 and 4.68 {\\mu}m as seen by a distant observer. The amplitude of variations and shape of the light curve is sensitive to the luminosity and mass ratios of the stars in the binary, the radius of the circumbinary disc clearing, the binary separation, and the orbital inclination. The light curve variations are smooth and very red with a non-sinusoidal shape for most of the parameter space explored. Possible morphologies include a single peak with a flat...

  10. Nonlinear bending waves in Keplerian accretion discs

    E-print Network

    G. I. Ogilvie

    2005-10-24

    The nonlinear dynamics of a warped accretion disc is investigated in the important case of a thin Keplerian disc with negligible viscosity and self-gravity. A one-dimensional evolutionary equation is formally derived that describes the primary nonlinear and dispersive effects on propagating bending waves other than parametric instabilities. It has the form of a derivative nonlinear Schroedinger equation with coefficients that are obtained explicitly for a particular model of a disc. The properties of this equation are analysed in some detail and illustrative numerical solutions are presented. The nonlinear and dispersive effects both depend on the compressibility of the gas through its adiabatic index Gamma. In the physically realistic case Gammanonlinearity does not lead to the steepening of bending waves but instead enhances their linear dispersion. In the opposite case Gamma>3, nonlinearity leads to wave steepening and solitary waves are supported. The effects of a small effective viscosity, which may suppress parametric instabilities, are also considered. This analysis may provide a useful point of comparison between theory and numerical simulations of warped accretion discs.

  11. MR IMAGING OF DEGENERATIVE DISC DISEASE

    Microsoft Academic Search

    William G. Bradley

    Magnetic Resonance Imaging (MRI) is being increasingly applied for the evaluation of degenerative disc disease in preference to X-ray computed tomography (CT). Unlike the comparison of MRI and CT in the brain, however, there is still a significant number of uses for CT in the evaluation of the extramedullary spinal column. Some of these relative advantages depend on how thin

  12. Disc Sec 20-A02 Discussion 7

    E-print Network

    California at Davis, University of

    ECS20_A Disc Sec 20-A02 Discussion 7 Fei Yu May 17, 2013 #12;Division Algorithm ! b à divisor, (b: ! the remainder cannot be negative ! the integers q and r are unique. #12;Division Algorithm_Examples ! a>0;Division Algorithm_Solutions ! a = 19, b = 3 ! a = bq + r ! 19 = 3 * 6 +1 ! a = 19, b = -3 ! 19 = (-3

  13. Lubricant replenishment on carbon coated discs

    Microsoft Academic Search

    X. Ma; J. Gui; B. Marchon; M. S. Jhon; C. L. Bauer; G. C. Rauch

    1999-01-01

    The replenishment of a lubricant on a carbon coated disc was characterized through theoretical modeling employing experimentally acquired diffusion coefficient data. To quantify the reflow behaviour of a lubricant film, a parameter, the critical reflow time, was defined as the time to replenish a depleted hole of 1 ?m diameter in a 2 nm thick lubricant film. The results based

  14. Pharmacological enhancement of disc diffusion and differentiation of healthy, ageing and degenerated discs

    Microsoft Academic Search

    S. Rajasekaran; K. Venkatadass; J. Naresh Babu; K. Ganesh; Ajoy P. Shetty

    2008-01-01

    Degenerative disc disease (DDD) is still a poorly understood phenomenon because of the lack of availability of precise definition\\u000a of healthy, ageing and degenerated discs. Decreased nutrition is the final common pathway for DDD and the status of the endplate\\u000a (EP) plays a crucial role in controlling the extent of diffusion, which is the only source of nutrition. The vascular

  15. Transplantation of mesenchymal stem cells embedded in Atelocollagen gel to the intervertebral disc: a potential therapeutic model for disc degeneration.

    PubMed

    Sakai, Daisuke; Mochida, Joji; Yamamoto, Yukihiro; Nomura, Takeshi; Okuma, Masahiko; Nishimura, Kazuhiro; Nakai, Tomoko; Ando, Kiyoshi; Hotta, Tomomitsu

    2003-09-01

    Intervertebral disc degeneration is considered to be one of the major causes of low back pain. Despite this irreversible phenomenon, attempts to decelerate disc degeneration using various techniques have been reported. However, to date there has been no proven technique effective for broad clinical application. Based on previous studies, we hypothesize that maintenance of proteoglycan content in the disc is achieved by avoiding the depletion of nucleus pulposus and preserving the structure of the annulus is a primary factor in decelerating disc degeneration. One novel approach to solve the dilemma of intervertebral disc degeneration is found at the stem cell level. Mesenchymal stem cells (MSCs) are known to possess the ability to differentiate into various kinds of cells from mesenchymal origin. Although the majority of cells that contribute to disc formation are known to obtain chondrocyte-like phenotypes, no reported study has emphasized the correlation with mesenchymal stem cells. To evaluate the possible potential of MSCs in disc cell research and treatment of degenerative disc disease, autologous MSCs embedded in Atelocollagen gel were transplanted into the discs of rabbits which had undergone a procedure proven to induce degeneration. The results suggest that MSC transplantation is effective in decelerating disc degeneration in experimental models and provided new hopes for treatment of degenerative disc disease in humans. Atelocollagen gel served as an important carrier of MSCs in transplantation, permitting proliferation, matrix synthesis and differentiation of MSCs. This study strengthens the viable efficacy of practical application of MSCs in treatment of intervertebral disc disease. PMID:12809782

  16. Enhancement of Overgrowth by Gene Interactions in Lethal(2)giant Discs Imaginal Discs from Drosophila Melanogaster

    PubMed Central

    Buratovich, M. A.; Bryant, P. J.

    1997-01-01

    Recessive lethal mutations of the lethal(2)giant discs (l(2)gd) and lethal(2)fat (l(2)ft) loci of Drosophila melanogaster cause imaginal disc hyperplasia during a prolonged larval stage. Imaginal discs from l(2)ft l(2)gd or Gl(2)gd double homozygotes show more extensive overgrowth than in either single homozygote, and double homozygous l(2)ft l(2)gd mitotic clones in adult flies show much more overgrowth than is seen in clones homozygous for either l(2)gd or l(2)ft alone. dachsous (ds) also acts as an enhancer of l(2)gd, producing dramatically overgrown discs and causing failure to pupariate in double homozygotes. The comb gap (cg) mutation, which also interacts with ds, greatly enhances the tendency of imaginal discs from l(2)gd larvae to duplicate as they overgrow. If l(2)gd homozygotes are made heterozygous for l(2)ft, then several discs duplicate, indicating that l(2)ft acts as a dominant enhancer of l(2)gd. l(2)ft also acts as a dominant enhancer of l(2)gd, and conversely l(2)gd acts as a dominant modifier of l(2)ft. The enhancement of overgrowth caused by various mutant combinations is accompanied by changes in expression of Decapentaplegic and Wingless. These results show that tumor suppressor genes act in combination to control cell proliferation, and that tissue hyperplasia can be associated with ectopic expression of genes involved in pattern formation. PMID:9335602

  17. Enhancement of overgrowth by gene interactions in lethal(2)giant discs imaginal discs from Drosophila melanogaster.

    PubMed

    Buratovich, M A; Bryant, P J

    1997-10-01

    Recessive lethal mutations of the lethal(2)giant discs (l(2)gd) and lethal(2)fat (l(2)ft) loci of Drosophila melanogaster cause imaginal disc hyperplasia during a prolonged larval stage. Imaginal discs from l(2)ft l(2)gd or Gl(2)gd double homozygotes show more extensive overgrowth than in either single homozygote, and double homozygous l(2)ft l(2)gd mitotic clones in adult flies show much more overgrowth than is seen in clones homozygous for either l(2)gd or l(2)ft alone. dachsous (ds) also acts as an enhancer of l(2)gd, producing dramatically overgrown discs and causing failure to pupariate in double homozygotes. The comb gap (cg) mutation, which also interacts with ds, greatly enhances the tendency of imaginal discs from l(2)gd larvae to duplicate as they overgrow. If l(2)gd homozygotes are made heterozygous for l(2)ft, then several discs duplicate, indicating that l(2)ft acts an a dominant enhancer of l(2)gd. l(2)ft also acts as a dominant enhancer of l(2)gd, and conversely l(2)gd acts as a dominant modifier of l(2)ft. The enhancement of overgrowth caused by various mutant combinations is accompanied by changes in expression of Decapentaplegic and Wingless. These results show that tumor suppressor genes act in combination to control cell proliferation, and that tissue hyperplasia can be associated with ectopic expression of genes involved in pattern formation. PMID:9335602

  18. Influence of blade profile of disc cutter on numerical simulation of the disc slitting process

    NASA Astrophysics Data System (ADS)

    Zeng, J.; Lu, J. B.; Yan, Q. S.; Li, S.

    2015-03-01

    The disc slitting machining experiments for electrical steel sheet were conducted to investigate the wear process of carbide alloy disc cutter and the slitting quality in the disc slitting process, and the blade contour shape of disc cutter in different slitting distance was measured by the surface profiler. A DEFORM-2D model, where the real blade profile or arc fitting profile was used as the blade contour of the cutter, was built to simulate the disc slitting process. Results show that the blade wear of disc cutter increases. The blade wear presents uneven in the side surface and cylindrical surface of the cutter, and the side wear is more serious with the increase of the slitting distance of electrical steel sheet. As the blade wear increases, the height of the rollover increases gradually, the height of the shear area increases at first and then decreases, but the height of the fracture area decreases at first and then increases. Compared with the arc fitting profile, the simulation surface morphology using the real blade profile is in good agreement with the experimental result. The variation of blade profile can change the distribution of the hydrostatic stress of sheet metal and the occurring and propagating of the crack, and the maximum hydrostatic stress can be used to estimate the change tendency of the fracture area.

  19. Collisional dust avalanches in debris discs

    E-print Network

    Anna Grigorieva; Pawel Artymowicz; Philippe Thébault

    2006-09-26

    We quantitatively investigate how collisional avalanches may developin debris discs as the result of the initial break-up of a planetesimal or comet-like object, triggering a collisional chain reaction due to outward escaping small dust grains. We use a specifically developed numerical code that follows both the spatial distribution of the dust grains and the evolution of their size-frequency distribution due to collisions. We investigate how strongly avalanche propagation depends on different parameters (e.g., amount of dust released in the initial break-up, collisional properties of dust grains and their distribution in the disc). Our simulations show that avalanches evolve on timescales of ~1000 years, propagating outwards following a spiral-like pattern, and that their amplitude exponentially depends on the number density of dust grains in the system. We estimate a probability for witnessing an avalanche event as a function of disc densities, for a gas-free case around an A-type star, and find that features created by avalanche propagation can lead to observable asymmetries for dusty systems with a beta Pictoris-like dust content or higher. Characteristic observable features include: (i) a brightness asymmetry of the two sides for a disc viewed edge-on, and (ii) a one-armed open spiral or a lumpy structure in the case of face-on orientation. A possible system in which avalanche-induced structures might have been observed is the edge-on seen debris disc around HD32297, which displays a strong luminosity difference between its two sides.

  20. Reduction of turbulent skin-friction drag by oscillating discs

    NASA Astrophysics Data System (ADS)

    Wise, Daniel; Ricco, Pierre

    2013-11-01

    A new drag-reduction method, based on the active technique proposed by Ricco & Hahn (2013), i.e. steadily rotating flush-mounted discs, is studied by DNS. The effect of sinusoidally oscillating discs on the turbulent channel-flow drag is investigated at Re? = 180 , based on the friction velocity of the stationary-wall case and the half channel height. A parametric investigation on the disc diameter, tip velocity and oscillation period yielded a maximum drag reduction of 18.5%. Regions of net power saved, calculated by considering the power spent to enforce the disc motion against the viscous resistance of the fluid, are found to reach up to 6.5% for low disc tip velocities. Significantly, the characteristic time-scale for the oscillating disc forcing is double that for the steadily rotating discs, representing a further step towards industrial implementation. The oscillating disc forcing, similar to the steadily rotating disc forcing, creates streamwise-elongated structures between the discs. These structures - largely unaffected by the periodic wall forcing and persisting throughout the entire period of the oscillation - are the main contributor to the additional Reynolds stresses term created by the disc forcing, and are important for the drag reduction mechanism.

  1. Examination of turbine discs from nuclear power plants

    SciTech Connect

    Czajkowski, C.J.; Weeks, J.R.

    1982-01-01

    Investigations were performed on a cracked turbine disc from the Cooper Nuclear Power Station, and on two failed turbine discs (governor and generator ends) from the Yankee-Rowe Nuclear Power Station. Cooper is a boiling water reactor (BWR) which went into commercial operation in July 1974, and Yankee-Rowe is a pressurized water reactor (PWR) which went into commercial operation in June 1961. Cracks were identified in the bore of the Cooper disc after 41,913 hours of operation, and the disc removed for repair. At Yankee-Rowe two discs failed after 100,000 hours of operation. Samples of the Cooper disc and both Yankee-Rowe disc (one from the governor and one from the generator end of the LP turbine) were sent to Brookhaven National Laboratory (BNL) for failure analysis.

  2. Correlation of matrix metalloproteinases-1 and tissue inhibitor of metalloproteinases-1 with patient age and grade of lumbar disk herniation.

    PubMed

    Xu, Haidong; Mei, Qiang; He, Jin; Liu, Gang; Zhao, Jianning; Xu, Bin

    2014-07-01

    The authors studied the nuclear magnetic resonance films and the expression of MMP-1 and TIMP-1 in disk specimens' of patients who had undergone operations for lumbar disk herniation. Forty-one lumbar disk patients were evaluated imaging for degenerative changes and their disk specimens immunohistochemical expression of MMP-1 and TIMP-1. The degree of degenerative changes was based on magnetic resonance imaging films. Sections of disk immunostained for MMP-1 and TIMP-1 were evaluated semiquantitatively. Patients were categorized in three age groups: <30 years, from 30 to 60 years, and >60 years of age. The expressions of MMP-1 and TIMP-1 were related to patients' age and degree of degenerative changes. There were statistical differences in the expression of MMP-1 and TIMP-1 between the age and degree of degenerative changes groups. With the degree of degenerative changes, the expression of MMP-1 and TIMP-1 increased obviously. But in old age group, the expression of MMP-1/TIMP-1 was higher than the young groups. The expressions of MMP-1 and TIMP-1 were strongly correlated to the age and the degree of the degenerative changes. An important finding in this study is the unbalance of the expression of MMP-1 and TIMP-1 along with the growth of the age. PMID:24442990

  3. What is vacuum?

    E-print Network

    Rowlands, Peter

    2008-01-01

    Vacuum can be defined with exact mathematical precision as the state which remains when a fermion, with all its special characteristics, is created out of absolutely nothing. The definition leads to a special form of relativistic quantum mechanics, which only requires the construction of a creation operator. This form of quantum mechanics is especially powerful for analytic calculation, at the same time as explaining, from first principles, many aspects of the Standard Model of particle physics. In particular, the characteristics of the weak, strong and electric interactions can be derived from the structure of the creation operator itself.

  4. What is vacuum?

    E-print Network

    Peter Rowlands

    2008-10-01

    Vacuum can be defined with exact mathematical precision as the state which remains when a fermion, with all its special characteristics, is created out of absolutely nothing. The definition leads to a special form of relativistic quantum mechanics, which only requires the construction of a creation operator. This form of quantum mechanics is especially powerful for analytic calculation, at the same time as explaining, from first principles, many aspects of the Standard Model of particle physics. In particular, the characteristics of the weak, strong and electric interactions can be derived from the structure of the creation operator itself.

  5. Avoiding Death by Vacuum

    E-print Network

    A. Barroso; P. M. Ferreira; I. Ivanov; R. Santos; Joao P. Silva

    2013-05-08

    The two-Higgs doublet model (2HDM) can have two electroweak breaking, CP-conserving, minima. The possibility arises that the minimum which corresponds to the known elementary particle spectrum is metastable, a possibility we call the "panic vacuum". We present analytical bounds on the parameters of the softly broken Peccei-Quinn 2HDM which are necessary and sufficient conditions to avoid this possibility. We also show that, for this particular model, the current LHC data already tell us that we are necessarily in the global minimum of the theory, regardless of any cosmological considerations about the lifetime of the false vacua.

  6. Polymers in a Vacuum

    SciTech Connect

    Deutsch, J. M. [Department of Physics, University of California, Santa Cruz, California 95064 (United States)

    2007-12-07

    In a variety of situations, isolated polymer molecules are found in a vacuum, and here we examine their properties. Angular momentum conservation is shown to significantly alter the average size of a chain and its conservation is only broken slowly by thermal radiation. For an ideal chain, the time autocorrelation for monomer position oscillates with a period proportional to chain length. The oscillations and damping are analyzed in detail. Short-range repulsive interactions suppress oscillations and speed up relaxation, but stretched chains still show damped oscillatory correlations.

  7. Optic Disc Hemorrhage Is Related to Various Hemodynamic Findings by Disc Angiography

    PubMed Central

    Park, Hae Young Lopilly; Jeong, Hyun Jin; Kim, Yoon Hee; Park, Chan Kee

    2015-01-01

    Background To investigate the hemodynamic characteristics of glaucoma eyes with disc hemorrhage (DH) by disc fluorescein angiography, and its relationship with glaucomatous changes of the optic disc and surrounding retinal nerve fiber layer (RNFL). Methods This study included 35 glaucoma eyes with DH who were followed up at least 5 years and had DH at presentation. Eyes were classified as eyes with DH at the border of localized RNFL defects and eyes with DH not related to localized RNFL defects. Prevalence of DH and location of the proximal border were recorded from disc photographs. Fluorescein angiography was performed 3 months after detecting the DH. Arm-retina time, arteriovenous transit time, disc filling time, choroidal filling time, and venous filling time were measured as retinal circulation parameters. The presence of disc filling defects and disc leaks were evaluated. Results There were 19 (54.3%) eyes with DH accompanying localized RNFL defects. The arm-retina time was prolonged in eyes with DH not related to RNFL defects (P = 0.044) and the arteriovenous transit time was prolonged in eyes with DH accompanying RNFL defects (P = 0.029). Among eyes with DH accompanying RNFL defects, 11 (57.9%) had vessel filling defects or delayed filling indicating blood flow stasis at the cup margin proximal to where DH occurred. Eyes with DH not related to RNFL defects did not show vessel filling defects or delayed filling. Conclusions and Relevance Eyes with DH related to RNFL defects showed prolonged arteriovenous transit time and had frequent vessel filling defects or delayed filling indicating blood flow stasis and thrombus formation at the site DH occurred. These findings suggest that vascular and hemodynamic changes due to glaucomatous structural changes cause DH in relation to localized RNFL defects. PMID:25879852

  8. Structure formation in gas-rich galactic discs with finite thickness: from discs to rings

    NASA Astrophysics Data System (ADS)

    Behrendt, M.; Burkert, A.; Schartmann, M.

    2015-03-01

    Gravitational instabilities play an important role in structure formation of gas-rich high-redshift disc galaxies. In this paper, we revisit the axisymmetric perturbation theory and the resulting growth of structure by taking the realistic thickness of the disc into account. In the unstable regime, which corresponds for thick discs to a Toomre parameter below the critical value Q0, crit = 0.696, we find a fastest growing perturbation wavelength that is always a factor 1.93 times larger than in the classical razor-thin disc approximation. This result is independent of the adopted disc scaleheight and by this independent of temperature and surface density. In order to test the analytical theory, we compare it with a high-resolution hydrodynamical simulation of an isothermal gravitationally unstable gas disc with the typical vertical sech2 density profile and study its break up into rings that subsequently fragment into dense clumps. In the first phase, rings form, that organize themselves discretely, with distances corresponding to the local fastest growing perturbation wavelength. We find that the disc scaleheight has to be resolved initially with five or more grid cells in order to guarantee proper growth of the ring structures, which follow the analytical prediction. These rings later on contract to a thin and dense line, while at the same time accreting more gas from the inter-ring region. It is these dense, circular filaments, that subsequently fragment into a large number of clumps. Contrary to what is typically assumed, the clump sizes are therefore not directly determined by the fastest growing wavelength.

  9. R&D ERL: Vacuum

    SciTech Connect

    Mapes, M.; Smart, L.; Weiss, D.; Steszyn, A.; Todd, R.

    2010-01-01

    The ERL Vacuum systems are depicted in a figure. ERL has eight vacuum volumes with various sets of requirements. A summary of vacuum related requirements is provided in a table. Five of the eight volumes comprise the electron beamline. They are the 5-cell Superconducting RF Cavity, Superconducting e-gun, injection, loop and beam dump. Two vacuum regions are the individual cryostats insulating the 5-cell Superconducting RF Cavity and the Superconducting e-gun structures. The last ERL vacuum volume not shown in the schematic is the laser transport line. The beamline vacuum regions are separated by electropneumatic gate valves. The beam dump is common with loop beamline but is considered a separate volume due to geometry and requirements. Vacuum in the 5-cell SRF cavity is maintained in the {approx}10{sup -9} torr range at room temperature by two 20 l/s ion pumps and in the e-gun SRF cavity by one 60 l/s ion pump. Vacuum in the SRF cavities operated at 2{sup o}K is reduced to low 10{sup -11} torr via cryopumping of the cavity walls. The cathode of the e-gun must be protected from poisoning, which can occur if vacuum adjacent to the e-gun in the injection line exceeds 10-11 torr range in the injection warm beamline near the e-gun exit. The vacuum requirements for beam operation in the loop and beam dump are 10-9 torr range. The beamlines are evacuated from atmospheric pressure to high vacuum level with a particulate free, oil free turbomolecular pumping cart. 25 l/s shielded ion pumps distributed throughout the beamlines maintain the vacuum requirement. Due to the more demanding vacuum requirement of the injection beamline proximate to the e-gun, a vacuum bakeout of the injection beamline is required. In addition, two 200 l/s diode ion pumps and supplemental pumping provided by titanium sublimation pumps are installed in the injection line just beyond the exit of the e-gun. Due to expected gas load a similar pumping arrangement is planned for the beam dump. The cryostat vacuum thermally insulating the SRF cavities need only reduce the convective heat load such that heat loss is primarily radiation through several layers of multi-layer insulation and conductive end-losses which are contained by 5{sup o}K thermal transitions. Prior to cool down rough vacuum {approx}10{sup -5} torr range is established and maintained by a dedicated turbomolecular pump station. Cryopumping by the cold mass and heat shields reduces the insulating vacuum to 10{sup -7} torr range after cool down.

  10. The avian intervertebral disc arises from rostral sclerotome and lacks a nucleus pulposus: Implications for evolution of the vertebrate disc

    PubMed Central

    Bruggeman, Bradley J.; Maier, Jennifer A.; Mohiuddin, Yasmin S.; Powers, Rae; Lo, YinTing; Guimarães-Camboa, Nuno; Evans, Sylvia M.; Harfe, Brian D.

    2012-01-01

    Deterioration of the intervertebral discs is an unfortunate consequence of aging. The intervertebral disc in mammals is composed of three parts: a jelly-like center called the nucleus pulposus, the cartilaginous annulus fibrosus and anterior and posterior endplates that attach the discs to vertebrae. In order to understand the origin of the disc, we have investigated the intervertebral region of chickens. Surprisingly, our comparison of mouse and chicken discs revealed that chicken discs lack nuclei pulposi. In addition, the notochord, which in mice forms nuclei pulposi, was found to persist as a rod-like structure and express Shh throughout chicken embryogenesis. Our fate mapping data indicates that cells originating from the rostral half of each somite are responsible for forming the avian disc while cells in the caudal region of each somite form vertebrae. A histological analysis of mammalian and non-mammalian organisms suggests that nuclei pulposi are only present in mammals. PMID:22354863

  11. Vacuum vapor deposition

    NASA Technical Reports Server (NTRS)

    Poorman, Richard M. (inventor); Weeks, Jack L. (inventor)

    1995-01-01

    A method and apparatus is described for vapor deposition of a thin metallic film utilizing an ionized gas arc directed onto a source material spaced from a substrate to be coated in a substantial vacuum while providing a pressure differential between the source and the substrate so that, as a portion of the source is vaporized, the vapors are carried to the substrate. The apparatus includes a modified tungsten arc welding torch having a hollow electrode through which a gas, preferably inert, flows and an arc is struck between the electrode and the source. The torch, source, and substrate are confined within a chamber within which a vacuum is drawn. When the arc is struck, a portion of the source is vaporized and the vapors flow rapidly toward the substrate. A reflecting shield is positioned about the torch above the electrode and the source to ensure that the arc is struck between the electrode and the source at startup. The electrode and the source may be confined within a vapor guide housing having a duct opening toward the substrate for directing the vapors onto the substrate.

  12. Changing MFTF vacuum environment

    SciTech Connect

    Margolies, D.; Valby, L.

    1982-12-01

    The Mirror Fusion Test Facility (MFTF) vacuum vessel will be about 60m long and 10m in diameter at the widest point. The allowable operating densities range from 2 x 10/sup 9/ to 5 x 10/sup 10/ particles per cc. The maximum leak rate of 10/sup -6/ tl/sec is dominated during operation by the deliberately injected cold gas of 250 tl/sec. This gas is pumped by over 1000 square meters of cryopanels, external sorption pumps and getters. The design and requirements have changed radically over the past several years, and they are still not in final form. The vacuum system design has also changed, but more slowly and less radically. This paper discusses the engineering effort necessary to meet these stringent and changing requirements. Much of the analysis of the internal systems has been carried out using a 3-D Monte Carlo computer code, which can estimate time dependent operational pressures. This code and its use will also be described.

  13. Motor actuated vacuum door

    NASA Astrophysics Data System (ADS)

    Hanagud, A. V.

    1986-10-01

    Doors that allow scientific instruments to record and retrieve the observed data are often required to be designed and installed as a part of sounding rocket hardware. The motor-actuated vacuum door was designed to maintain a medium vacuum of the order of 0.0001 torr or better while closed, and to provide an opening 15 inches long x 8.5 inches wide while open for cameras to image Halley's comet. When the electric motor receives the instruction to open the door through the payload battery, timer, and relay circuit, the first operation is to unlock the door. After unlatching, the torque transmitted by the motor to the main shaft through the links opens the door. A microswitch actuator, which rides on the linear motion conversion mechanism, is adjusted to trip the limit switch at the end of the travel. The process is repeated in the reverse order to close the door. 'O' rings are designed to maintain the seal. Door mechanisms similar to the one described have flown on Aerobee 17.018 and Black Brant 27.047 payloads.

  14. Cervical Intervertebral Disc Protrusion in Two Horses

    PubMed Central

    Foss, R. R.; Genetzky, R. M.; Riedesel, E. A.; Graham, C.

    1983-01-01

    Two horses with ataxia of all four limbs were found to have cervical intervertebral disc protrusion. Severe pelvic limb ataxia, proprioceptive deficits and spasticity were present in both horses with similar but less severe signs in the thoracic limbs. Cerebrospinal fluid analysis was within normal limits. Metrizamide myelography allowed definitive diagnosis in one case when a compression of the spinal cord was demonstrated at the level of the second intervertebral space. In the second case, an intervertebral disc protrusion between cervical vertebrae 6 and 7 was found at necropsy. Fiber degeneration with poor myelin staining characterized the spinal cords histologically. ImagesFigure 1.Figure 2a.Figure 2b.Figure 3. PMID:17422269

  15. Inflammation in intervertebral disc degeneration and regeneration

    PubMed Central

    Molinos, Maria; Almeida, Catarina R.; Caldeira, Joana; Cunha, Carla; Gonçalves, Raquel M.; Barbosa, Mário A.

    2015-01-01

    Intervertebral disc (IVD) degeneration is one of the major causes of low back pain, a problem with a heavy economic burden, which has been increasing in prevalence as populations age. Deeper knowledge of the complex spatial and temporal orchestration of cellular interactions and extracellular matrix remodelling is critical to improve current IVD therapies, which have so far proved unsatisfactory. Inflammation has been correlated with degenerative disc disease but its role in discogenic pain and hernia regression remains controversial. The inflammatory response may be involved in the onset of disease, but it is also crucial in maintaining tissue homeostasis. Furthermore, if properly balanced it may contribute to tissue repair/regeneration as has already been demonstrated in other tissues. In this review, we focus on how inflammation has been associated with IVD degeneration by describing observational and in vitro studies as well as in vivo animal models. Finally, we provide an overview of IVD regenerative therapies that target key inflammatory players. PMID:25673296

  16. Low partial discharge vacuum feedthrough

    NASA Technical Reports Server (NTRS)

    Benham, J. W.; Peck, S. R.

    1979-01-01

    Relatively discharge free vacuum feedthrough uses silver-plated copper conductor jacketed by carbon filled silicon semiconductor to reduce concentrated electric fields and minimize occurrence of partial discharge.

  17. Programmed cell death in intervertebral disc degeneration

    Microsoft Academic Search

    Chang-Qing Zhao; Lei-Sheng Jiang; Li-Yang Dai

    2006-01-01

    Intervertebral disc (IVD) degeneration is largely a process of destruction and failure of the extracellular matrix (ECM),\\u000a and symptomatic IVD degeneration is thought to be one of the leading causes of morbidity or life quality deterioration in\\u000a the elderly. To date, however, the mechanism of IVD degeneration is still not fully understood. Cellular loss from cell death\\u000a in the process

  18. Radiographic identification of ingested disc batteries

    Microsoft Academic Search

    M. D. Maves; T. V. Lloyd; J. S. Carithers

    1986-01-01

    Recently, the hazards posed by the accidental ingestion and impaction of small disc batteries have been widely publicized\\u000a in the medical and lay press. These foreign bodies, when lodged in the esophagus, leak a caustic solution of 26 to 45% sodium\\u000a or potassium hydroxide which can cause a burn injury to the esophagus in a very short period of time.

  19. Mechanical Behavior of Isolated Intervertebral Disc

    Microsoft Academic Search

    F. F. Lemos; J. E. Tomazini; U. G. Oliveira

    \\u000a The study on several components of intervertebral joints is essential to understand the spine’s degenerative mechanisms and\\u000a to assess the best method for their treatment. For such study it is necessary to know the mechanical properties of the isolated\\u000a intervertebral disc (ID) mechanical properties and, it is necessary to evaluate its stresses and strains. In order to assess\\u000a the ID

  20. Optic disc morphology in pigmentary glaucoma

    Microsoft Academic Search

    Jost B Jonas; Albert Dichtl; Wido M Budde; Peter Lang

    1998-01-01

    AIMTo evaluate the morphology of the optic nerve head in eyes with pigmentary glaucoma.METHODSColour stereo optic disc photographs of 62 patients with pigmentary glaucoma and 566 patients with primary open angle glaucoma were morphometrically evaluated. By prestudy selection, mean visual field defect and neuroretinal rim area were not significantly different between the two groups (p=0.89 and p=0.45).RESULTSThe pigmentary glaucoma group

  1. Demographics of transition discs in Ophiuchus and Taurus

    NASA Astrophysics Data System (ADS)

    Najita, Joan R.; Andrews, Sean M.; Muzerolle, James

    2015-07-01

    Transition disc systems are young stars that appear to be on the verge of dispersing their protoplanetary discs. We explore the nature of these systems by comparing the stellar accretion rates dot{M}_* and disc masses Md of transition discs and normal T Tauri stars in Taurus and Ophiuchus. After controlling for the known dependences of dot{M}_* and Md on age, dot{M}_* on stellar mass and Md on the presence of stellar or substellar companions, we find that the normal T Tauri stars show a trend of dot{M}_* increasing with Md. The transition discs tend to have higher average disc masses than normal T Tauri stars as well as lower accretion rates than normal T Tauri stars of the same disc mass. These results are most consistent with the interpretation that the transition discs have formed objects massive enough to alter the accretion flow, i.e. single or multiple giant planets. Several Ophiuchus T Tauri stars that are not known transition disc systems also have very low accretion rates for their disc masses. We speculate on the possible nature of these sources.

  2. Vertical shear instability in accretion disc models with radiation transport

    NASA Astrophysics Data System (ADS)

    Stoll, Moritz H. R.; Kley, Wilhelm

    2014-12-01

    Context. The origin of turbulence in accretion discs is still not fully understood. While the magneto-rotational instability is thought to operate in sufficiently ionised discs, its role in the poorly ionised protoplanetary disc is questionable. Recently, the vertical shear instability (VSI) has been suggested as a possible alternative. Aims: Our goal is to study the characteristics of this instability and the efficiency of angular momentum transport, in extended discs, under the influence of radiative transport and irradiation from the central star. Methods: We use multi-dimensional hydrodynamic simulations to model a larger section of an accretion disc. First we study inviscid and weakly viscous discs using a fixed radial temperature profile in two and three spatial dimensions. The simulations are then extended to include radiative transport and irradiation from the central star. Results: In agreement with previous studies, for the isothermal disc we find a sustained unstable state with a weak positive angular momentum transport of the order of ? ? 10-4. Under the inclusion of radiative transport the disc cools off and the turbulence terminates. For discs irradiated from the central star we again find a persistent instability with a similar ? value as for the isothermal case. Conclusions: We find that the VSI can indeed generate sustained turbulence in discs, albeit at a relatively low level with ? about few times 10-4.

  3. Macroscopic changes during negative pressure wound therapy of the open abdomen using conventional negative pressure wound therapy and NPWT with a protective disc over the intestines

    Microsoft Academic Search

    Sandra Lindstedt; Malin Malmsjö; Johan Hansson; Joanna Hlebowicz; Richard Ingemansson

    2011-01-01

    Background  Higher closure rates of the open abdomen have been reported with negative pressure wound therapy (NPWT) than with other wound\\u000a management techniques. However, the method has occasionally been associated with increased development of fistulae. We have\\u000a previously shown that NPWT induces ischemia in the underlying small intestines close to the vacuum source, and that a protective\\u000a disc placed between the

  4. Arrhythmogenic cardiomyopathy: a disease of intercalated discs.

    PubMed

    Calore, Martina; Lorenzon, Alessandra; De Bortoli, Marzia; Poloni, Giulia; Rampazzo, Alessandra

    2015-06-01

    Arrhythmogenic cardiomyopathy (ACM) is an acquired progressive disease having an age-related penetrance and showing clinical manifestations usually during adolescence and young adulthood. It is characterized clinically by a high incidence of severe ventricular tachyarrhythmias and sudden cardiac death and pathologically by degeneration of ventricular cardiomyocytes with replacement by fibro-fatty tissue. Whereas, in the past, the disease was considered to involve only the right ventricle, more recent clinical studies have established that the left ventricle is frequently involved. ACM is an inherited disease in up to 50 % of cases, with predominantly an autosomal dominant pattern of transmission, although recessive inheritance has also been described. Since most of the pathogenic mutations have been identified in genes encoding desmosomal proteins, ACM is currently defined as a disease of desmosomes. However, on the basis of the most recent description of the intercalated disc organization and of the identification of a novel ACM gene encoding for an area composita protein, ACM can be considered as a disease of the intercalated disc, rather than only as a desmosomal disease. Despite increasing knowledge of the genetic basis of ACM, we are just beginning to understand early molecular events leading to cardiomyocyte degeneration, fibrosis and fibro-fatty substitution. This review summarizes recent advances in our comprehension of the link between the molecular genetics and pathogenesis of ACM and of the novel role of cardiac intercalated discs. PMID:25344329

  5. Accretion disc origin of the Earth's water.

    PubMed

    Vattuone, Luca; Smerieri, Marco; Savio, Letizia; Asaduzzaman, Abu Md; Muralidharan, Krishna; Drake, Michael J; Rocca, Mario

    2013-07-13

    Earth's water is conventionally believed to be delivered by comets or wet asteroids after the Earth formed. However, their elemental and isotopic properties are inconsistent with those of the Earth. It was thus proposed that water was introduced by adsorption onto grains in the accretion disc prior to planetary growth, with bonding energies so high as to be stable under high-temperature conditions. Here, we show both by laboratory experiments and numerical simulations that water adsorbs dissociatively on the olivine {100} surface at the temperature (approx. 500-1500 K) and water pressure (approx. 10?? bar) expected for the accretion disc, leaving an OH adlayer that is stable at least up to 900 K. This may result in the formation of many Earth oceans, provided that a viable mechanism to produce water from hydroxyl exists. This adsorption process must occur in all disc environments around young stars. The inevitable conclusion is that water should be prevalent on terrestrial planets in the habitable zone around other stars. PMID:23734050

  6. Control Dewar Secondary Vacuum Container

    SciTech Connect

    Rucinski, R.; /Fermilab

    1993-10-04

    This engineering note provides background information regarding the control dewar secondary vacuum container. The secondary vacuum container has it's origin with the CDP control dewar design. The name secondary vacuum container replaced the CDP term 'Watt can' which was named after Bob Watt (SLAC), a PAC/DOE review committee member who participated in a review of CDP and recommended a secondary vacuum enclosure. One of the most fragile parts of the control dewar design is the ceramic electrical feed throughs located in the secondary vacuum container. The secondary vacuum container is provided to guard against potential leaks in these ceramic insulating feed throughs. The secondary vacuum container has a pumping line separate from the main solenoid/control dewar insulating vacuum. This pumping line is connected to the inlet of the turbo pump for initial pumpdown. Under normal operation the container is isolated. Should a feedthrough develop a small leak, alternate pumping arrangements for the secondary vacuum container could be arranged. The pressure in the secondary vacuum container should be kept in a range that the breakdown voltage is kept at a maximum. The breakdown voltage is known to be a function of pressure and is described by a Paschen curve. I cannot find a copy of the curve at this time, but from what I remember, the breakdown voltage is a minimum somewhere around 10-3 torr. Ideally the pressure in the secondary vacuum can should be kept very low, around 10 E-6 or 10 E-7 torr for maximum breakdown voltage. If however a leak developed and this was not possible, then one could operate at a pressure higher than the minima point.

  7. Entrapment Type Vacuum Pumps

    NSDL National Science Digital Library

    This is a description for a learning module from Maricopa Advanced Technology Education Center. This PDF describes the module; access may be purchased by visiting the MATEC website. Entrapment type pumps operate primarily in the high to ultra-high vacuum ranges. The discussion in this MATEC module includes applications, theory of operation, operating range and preventative maintenance. The focus is on three major types of pumps: cryosorption, cryogenic and sputter-ion. The overall performance of these types of pumps depends on a variety of parameters. For example, it is important that learners understand the balance between pumping speed and capacity. Competency is demonstrated as the learners specify systems for defined process applications.

  8. Modeling Vacuum Arcs

    E-print Network

    Insepov, Z; Proslier, T; Huang, D; Mahalingam, S; Veitzer, S

    2010-01-01

    We are developing a model of vacuum arcs. This model assumes that arcs develop as a result of mechanical failure of the surface due to Coulomb explosions, followed by ionization of fragments by field emission and the development of a small, dense plasma that interacts with the surface primarily through self sputtering and terminates as a unipolar arc capable of producing breakdown sites with high enhancement factors. We have attempted to produce a self consistent picture of triggering, arc evolution and surface damage. We are modeling these mechanisms using Molecular Dynamics (mechanical failure, Coulomb explosions, self sputtering), Particle-In-Cell (PIC) codes (plasma evolution), mesoscale surface thermodynamics (surface evolution), and finite element electrostatic modeling (field enhancements). We can present a variety of numerical results. We identify where our model differs from other descriptions of this phenomenon.

  9. Radiation magnetohydrodynamics in global simulations of protoplanetary discs

    NASA Astrophysics Data System (ADS)

    Flock, M.; Fromang, S.; González, M.; Commerçon, B.

    2013-12-01

    Aims: Our aim is to study the thermal and dynamical evolution of protoplanetary discs in global simulations, including the physics of radiation transfer and magneto-hydrodynamic turbulence caused by the magneto-rotational instability. Methods: We have developed a radiative transfer method based on the flux-limited diffusion approximation that includes frequency dependent irradiation by the central star. This hybrid scheme is implemented in the PLUTO code. The focus of our implementation is on the performance of the radiative transfer method. Using an optimized Jacobi preconditioned BiCGSTAB solver, the radiative module is three times faster than the magneto-hydrodynamic step for the disc set-up we consider. We obtain weak scaling efficiencies of 70% up to 1024 cores. Results: We present the first global 3D radiation magneto-hydrodynamic simulations of a stratified protoplanetary disc. The disc model parameters were chosen to approximate those of the system AS 209 in the star-forming region Ophiuchus. Starting the simulation from a disc in radiative and hydrostatic equilibrium, the magneto-rotational instability quickly causes magneto-hydrodynamic turbulence and heating in the disc. We find that the turbulent properties are similar to that of recent locally isothermal global simulations of protoplanetary discs. For example, the rate of angular momentum transport ? is a few times 10-3. For the disc parameters we use, turbulent dissipation heats the disc midplane and raises the temperature by about 15% compared to passive disc models. The vertical temperature profile shows no temperature peak at the midplane as in classical viscous disc models. A roughly flat vertical temperature profile establishes in the optically thick region of the disc close to the midplane. We reproduce the vertical temperature profile with viscous disc models for which the stress tensor vertical profile is flat in the bulk of the disc and vanishes in the disc corona. Conclusions: The present paper demonstrates for the first time that global radiation magneto-hydrodynamic simulations of turbulent protoplanetary discs are feasible with current computational facilities. This opens up the window to a wide range of studies of the dynamics of the inner parts of protoplanetary discs, for which there are significant observational constraints.

  10. Genetic and Functional Studies of the Intervertebral Disc: A Novel Murine Intervertebral Disc Model

    PubMed Central

    Pelle, Dominic W.; Peacock, Jacqueline D.; Schmidt, Courtney L.; Kampfschulte, Kevin; Scholten, Donald J.; Russo, Scott S.; Easton, Kenneth J.; Steensma, Matthew R.

    2014-01-01

    Intervertebral disc (IVD) homeostasis is mediated through a combination of micro-environmental and biomechanical factors, all of which are subject to genetic influences. The aim of this study is to develop and characterize a genetically tractable, ex vivo organ culture model that can be used to further elucidate mechanisms of intervertebral disc disease. Specifically, we demonstrate that IVD disc explants (1) maintain their native phenotype in prolonged culture, (2) are responsive to exogenous stimuli, and (3) that relevant homeostatic regulatory mechanisms can be modulated through ex-vivo genetic recombination. We present a novel technique for isolation of murine IVD explants with demonstration of explant viability (CMFDA/propidium iodide staining), disc anatomy (H&E), maintenance of extracellular matrix (ECM) (Alcian Blue staining), and native expression profile (qRT-PCR) as well as ex vivo genetic recombination (mT/mG reporter mice; AdCre) following 14 days of culture in DMEM media containing 10% fetal bovine serum, 1% L-glutamine, and 1% penicillin/streptomycin. IVD explants maintained their micro-anatomic integrity, ECM proteoglycan content, viability, and gene expression profile consistent with a homeostatic drive in culture. Treatment of genetically engineered explants with cre-expressing adenovirus efficaciously induced ex vivo genetic recombination in a variety of genetically engineered mouse models. Exogenous administration of IL-1ß and TGF-ß3 resulted in predicted catabolic and anabolic responses, respectively. Genetic recombination of TGFBR1fl/fl explants resulted in constitutively active TGF-ß signaling that matched that of exogenously administered TGF-ß3. Our results illustrate the utility of the murine intervertebral disc explant to investigate mechanisms of intervertebral disc degeneration. PMID:25474689

  11. Accretion disc viscosity: a limit on the anisotropy

    NASA Astrophysics Data System (ADS)

    Nixon, Chris

    2015-07-01

    Observations of warped discs can give insight into the nature of angular momentum transport in accretion discs. Only a few objects are known to show strong periodicity on long time-scales, but when such periodicity is present it is often attributed to precession of the accretion disc. The X-ray binary Hercules X-1/HZ Herculis (Her X-1) is one of the best examples of such periodicity and has been linked to disc precession since it was first observed. By using the current best-fitting models to Her X-1, which invoke precession driven by radiation warping, I place a constraint on the effective viscosities that act in a warped disc. These effective viscosities almost certainly arise due to turbulence induced by the magnetorotational instability. The constraints derived here are in agreement with analytical and numerical investigations into the nature of magnetohydrodynamic disc turbulence, but at odds with some recent global simulations.

  12. The Application of Fiber-Reinforced Materials in Disc Repair

    PubMed Central

    Pei, Bao-Qing; Li, Hui; Zhu, Gang; Li, De-Yu; Fan, Yu-Bo; Wu, Shu-Qin

    2013-01-01

    The intervertebral disc degeneration and injury are the most common spinal diseases with tremendous financial and social implications. Regenerative therapies for disc repair are promising treatments. Fiber-reinforced materials (FRMs) are a kind of composites by embedding the fibers into the matrix materials. FRMs can maintain the original properties of the matrix and enhance the mechanical properties. By now, there are still some problems for disc repair such as the unsatisfied static strength and dynamic properties for disc implants. The application of FRMs may resolve these problems to some extent. In this review, six parts such as background of FRMs in tissue repair, the comparison of mechanical properties between natural disc and some typical FRMs, the repair standard and FRMs applications in disc repair, and the possible research directions for FRMs' in the future are stated. PMID:24383057

  13. [NeII] emission line profiles from photoevaporative disc winds

    E-print Network

    R. D. Alexander

    2008-09-01

    I model profiles of the [NeII] forbidden emission line at 12.81um, emitted by photoevaporative winds from discs around young, solar-mass stars. The predicted line luminosities (~ 1E-6 Lsun) are consistent with recent data, and the line profiles vary significantly with disc inclination. Edge-on discs show broad (30-40km/s) double-peaked profiles, due to the rotation of the disc, while in face-on discs the structure of the wind results in a narrower line (~10km/s) and a significant blue-shift (5-10km/s). These results suggest that observations of [NeII] line profiles can provide a direct test of models of protoplanetary disc photoevaporation.

  14. Disc1 Variation Leads to Specific Alterations in Adult Neurogenesis

    PubMed Central

    Chandran, Jayanth S.; Kazanis, Ilias; Clapcote, Steven J.; Ogawa, Fumiaki; Millar, J. Kirsty; Porteous, David J.; ffrench-Constant, Charles

    2014-01-01

    Disrupted in schizophrenia 1 (DISC1) is a risk factor for a spectrum of neuropsychiatric illnesses including schizophrenia, bipolar disorder, and major depressive disorder. Here we use two missense Disc1 mouse mutants, described previously with distinct behavioural phenotypes, to demonstrate that Disc1 variation exerts differing effects on the formation of newly generated neurons in the adult hippocampus. Disc1 mice carrying a homozygous Q31L mutation, and displaying depressive-like phenotypes, have fewer proliferating cells while Disc1 mice with a homozygous L100P mutation that induces schizophrenia-like phenotypes, show changes in the generation, placement and maturation of newly generated neurons in the hippocampal dentate gyrus. Our results demonstrate Disc1 allele specific effects in the adult hippocampus, and suggest that the divergence in behavioural phenotypes may in part stem from changes in specific cell populations in the brain. PMID:25272038

  15. Accretion disc viscosity: a limit on the anisotropy

    E-print Network

    Nixon, Chris

    2015-01-01

    Observations of warped discs can give insight into the nature of angular momentum transport in accretion discs. Only a few objects are known to show strong periodicity on long timescales, but when such periodicity is present it is often attributed to precession of the accretion disc. The X-ray binary Hercules X-1/HZ Herculis (Her X-1) is one of the best examples of such periodicity and has been linked to disc precession since it was first observed. By using the current best-fitting models to Her X-1, which invoke precession driven by radiation warping, I place a constraint on the effective viscosities that act in a warped disc. These effective viscosities almost certainly arise due to turbulence induced by the magneto-rotational instability. The constraints derived here are in agreement with analytical and numerical investigations into the nature of magneto-hydrodynamic disc turbulence, but at odds with some recent global simulations.

  16. Cartridge getter for vacuum jacketing

    NASA Technical Reports Server (NTRS)

    Luebbers, C. J.

    1977-01-01

    Inexpensively-manufactured getter cartridge save users time in vacuum system maintenance and allows almost anyone to carry out replacement procedure that formerly required skilled welder. Cartridge screws into port in outer wall of vacuum jacket. Getter is replaced by simply unscrewing cartridge rather than cutting and rewelding.

  17. Technical specification for vacuum systems

    Microsoft Academic Search

    Khaw

    1987-01-01

    The vacuum systems at the Stanford Linear Accelerator Center (SLAC) are primarily of all-metal construction and operate at pressures from 10 to 10¹¹ Torr. The primary gas loads during operation result from thermal desorption and beam-induced desorption from the vacuum chamber walls. These desorption rates can be extremely high in the case of hydrocarbons and other contaminants. These specifications place

  18. Anode modes in vacuum arcs

    Microsoft Academic Search

    H. Craig Miller

    1997-01-01

    This paper reviews the five different anode discharge modes which can occur in a vacuum arc. These modes are diffuse arc (low current, with or without anode sputtering), footpoint (intermediate current), and anode spot or intense arc (high current). Descriptions of the various modes are presented, based primarily on experimental results. The hot anode vacuum arc mode, which occurs only

  19. Joint Nonparametric Alignment for Analyzing Spatial Gene Expression Patterns in Drosophila Imaginal Discs

    E-print Network

    Sastry, S. Shankar

    Discs Parvez Ahammad , Cyrus L. Harmon , Ann Hammonds , S. Shankar Sastry and Gerald M. Rubin Abstract. First row: wing discs, second row: haltere discs, third row: leg discs, fourth row: eye discs system for the generation of large numbers of images which can then be processed by either human

  20. Vacuum energy as dark matter

    NASA Astrophysics Data System (ADS)

    Albareti, F. D.; Cembranos, J. A. R.; Maroto, A. L.

    2014-12-01

    We consider the vacuum energy of massive quantum fields in an expanding universe. We define a conserved renormalized energy-momentum tensor by means of a comoving cutoff regularization. Using exact solutions for de Sitter space-time, we show that in a certain range of mass and renormalization scales there is a contribution to the vacuum energy density that scales as nonrelativistic matter and that such a contribution becomes dominant at late times. By means of the WKB approximation, we find that these results can be extended to arbitrary Robertson-Walker geometries. We study the range of parameters in which the vacuum energy density would be compatible with current limits on dark matter abundance. Finally, by calculating the vacuum energy in a perturbed Robertson-Walker background, we obtain the speed of sound of density perturbations and show that the vacuum energy density contrast can grow on sub-Hubble scales as in standard cold dark matter scenarios.