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1

Herniated Lumbar Disc  

MedlinePLUS

... be treated with nonprescription medications such as aspirin, ibuprofen, naproxen or acetaminophen. If you have severe persistent ... a result of disc herniation. These include asprin, ibuprofen, naproxen and a variety of prescription drugs. If ...

2

Lumbar Disc Herniation in Adolescence  

Microsoft Academic Search

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

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

2007-01-01

3

[Cervical disc herniation].  

PubMed

The cervical disc herniation is characterized by prolapsed nucleus pulposus material through the annulus into the spinal canal. The local mechanical or chemical irritation of neural structures typically leads to symptoms of radiculopathy, cervicocephalgia or myelopathy. Pronounced sensorimotor deficits or intractable pain constitute surgical treatment. In all other cases conservative treatment is indicated, including pain medication, active and passive physiotherapy, and local injections, respectively. Anterior cervical discectomy and interbody fusion (ACDF) is still the surgical treatment of choice. Predominantly, cages with or without plates are in use to obtain solid fusion. The implantation of a total disc replacement is a viable alternative, if no contraindications exist. Other surgical techniques may be performed in proper selected cases. The overall clinical and radiological results of both surgical and conservative treatment are good. PMID:23296562

Schnake, K J; Hoffmann, C-H; Kandziora, F

2012-12-01

4

Autotraction in lumbar disc herniation  

Microsoft Academic Search

Autotraction is a method of diminishing lower back pain and sciatica in which the patient stretches himself on a specially designed traction table. The pulling force ranges between 400–800 N. Clinical results are encouraging and the method can be recommended as a temporary treatment especially in lumbago with sciatica. The influence on a herniated disc is discussed with respect to

P. Gillström; K. Ericson; T. Hindmarsh

1985-01-01

5

Percutaneous Intradiscal Aspiration of a Lumbar Vacuum Disc Herniation: A Case Report  

Microsoft Academic Search

We report a case of an 83-year-old gentleman presenting with acute low back pain and radicular left lower extremity pain after\\u000a golfing. A magnetic resonance imaging (MRI) of the lumbar spine revealed a low-signal-density lesion compressing the L5 nerve.\\u000a A computed tomography scan was then ordered, confirming an extra-foraminal disc protrusion at the L5–S1 level, containing\\u000a a focus of gas

Kevin I. Pak; David C. Hoffman; Richard J. Herzog; Gregory E. Lutz

2011-01-01

6

Herniation of the upper lumbar discs  

Microsoft Academic Search

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

E. Pásztor; I. Szarvas

1981-01-01

7

Percutaneous Treatment of Intervertebral Disc Herniation  

Microsoft Academic Search

\\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

Xavier Buy; Afshin Gangi; Stéphane Guth; Ali Guermazi

8

Acupuncture and Spontaneous Regression of a Radiculopathic Cervical Herniated Disc  

PubMed Central

The spontaneous regression of herniated cervical discs is not a well-established phenomenon. However, we encountered a case of a spontaneous regression of a severe radiculopathic herniated cervical disc that was treated with acupuncture, pharmacopuncture, and herb medicine. The symptoms were improved within 12 months of treatment. Magnetic resonance imaging (MRI) conducted at that time revealed marked regression of the herniated disc. This case provides an additional example of spontaneous regression of a herniated cervical disc documented by MRI following non-surgical treatment. PMID:25780641

Kim, Sung-Ha; Park, Man-Young; Lee, Sang-Mi; Jung, Ho-Hyun; Kim, Jae-Kyoun; Lee, Jong-Deok; Kim, Dong-Woung; Yeom, Seung-Ryong; Lim, Jin-Young; Park, Min-Jung; Park, Se-Woon; Kim, Sung-Chul

2012-01-01

9

Low-Back Pain Following Surgery for Lumbar Disc Herniation  

Microsoft Academic Search

Background: Lumbar disc herniation often causes sciatica. Although surgery may provide relief of sciatic pain, it is uncertain how surgery affects the relief of low-back pain. The purpose of the present prospective study was to assess the efficacy of discectomy in the treatment of low-back pain associated with lumbar disc herniation. Methods: Between 1998 and 2001, forty consecutive patients with

TOMOAKI TOYONE; TADASHI TANAKA; DAISUKE KATO; RYUTAKU KANEYAMA

10

Risk Factors for Recurrent Lumbar Disc Herniations  

PubMed Central

The most common complication after lumbar discectomy is reherniation. As the first step in reducing the rate of recurrence, many studies have been conducted to find out the factors that may increase the reherniation risk. Some reported factors are age, sex, the type of lumbar disc herniation, the amount of fragments removed, smoking, alcohol consumption and the length of restricted activities. In this review, the factors studied thus far are summarized, excepting factors which cannot be chosen or changed, such as age or sex. Apart from the factors shown here, many other risk factors such as diabetes, family history, history of external injury, duration of illness and body mass index are considered. Few are agreed upon by all. The reason for the diverse opinions may be that many clinical and biomechanical variables are involved in the prognosis following operation. For the investigation of risk factors in recurrent lumbar disc herniation, large-scale multicenter prospective studies will be required in the future. PMID:24761206

2014-01-01

11

Percutaneous cervical nucleoplasty in the treatment of cervical disc herniation  

Microsoft Academic Search

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

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

2008-01-01

12

[Lumbar disc herniation--diagnosis and treatment].  

PubMed

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

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

2014-12-10

13

Sacral Perineural Cyst Accompanying Disc Herniation  

PubMed Central

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

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

2009-01-01

14

Percutaneous treatment of cervical and lumbar herniated disc.  

PubMed

Therapeutic armamentarium for symptomatic intervertebral disc herniation includes conservative therapy, epidural infiltrations (interlaminar or trans-foraminal), percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments for intervertebral disc herniation which can be performed as outpatient procedures. They can be classified in 4 main categories: mechanical, thermal, chemical decompression and biomaterials implantation. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. Indications include the presence of a symptomatic, small to medium sized contained intervertebral disc herniation non-responding to a 4-6 weeks course of conservative therapy. Contraindications include sequestration, infection, segmental instability (spondylolisthesis), uncorrected coagulopathy or a patient unwilling to provide informed consent. Decompression techniques are feasible and reproducible, efficient (75-94% success rate) and safe (>0.5% mean complications rate) therapies for the treatment of symptomatic intervertebral disc herniation. Percutaneous, imaging guided, intervertebral disc therapeutic techniques can be proposed either as an initial treatment or as an attractive alternative prior to surgery for the therapy of symptomatic herniation in both cervical and lumbar spine. This article will describe the mechanism of action for different therapeutic techniques applied to intervertebral discs of cervical and lumbar spine, summarize the data concerning safety and effectiveness of these treatments, and provide a rational approach for the therapy of symptomatic intervertebral disc herniation in cervical and lumbar spine. PMID:24673977

Kelekis, A; Filippiadis, D K

2015-05-01

15

Lumbar Spine Disc Herniation Diagnosis with a Joint Shape Model  

E-print Network

Lumbar Spine Disc Herniation Diagnosis with a Joint Shape Model Raja S Alomari1 , Jason J Corso1 diagnosis of the DDD for lumbar spine. We design a classifier to automatically detect degenerated disc (also. Keywords: Lumbar Spine Diagnosis, MRI, Disc Degenerative Disease 1 Introduction Low Back Pain has a major

Corso, Jason J.

16

A Symptomatic Spinal Extradural Arachnoid Cyst with Lumbar Disc Herniation  

PubMed Central

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.

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

2015-01-01

17

Thoracic Disc Herniation Presenting with Transient Anterior Spinal Artery Syndrome  

PubMed Central

Summary This report is a clinical and radiologic correlation of anterior spinal arterial distribution ischemia with a thoracic disc herniation affecting the artery of Adamkiewicz. We could only find one other similar reported case. A 38-year-old woman developed sudden onset of severe back pain and radiculopathy, followed by rapidly evolving paraparesis. The neurological examination was consistent with a deficit caused by anterior spinal artery ischemia. MRI revealed T2 signal change in the thoracolumbar spinal cord and a laterally placed, non-calcified disc herniation. Selective spinal angiography performed 30 hours after onset revealed displacement of the left T9 radicular feeding artery by the disc herniation; at this time the artery was patent. The patient experienced some resolution of symptoms within the first 24 hours and was managed conservatively and made a significant recovery within two weeks. Appropriately located thoracic disc herniations can disturb the blood supply to the thoracolumbar spinal cord. PMID:20667212

Guest, J.D.; Griesdale, D.E.; Marotta, T.

2000-01-01

18

Traumatic Intradural Lumbar Disc Herniation without Bone Injury  

PubMed Central

Intradural lumbar disc herniation is a rare disease. According to the reports of intradural lumbar disc herniations, most cases have developed as a chronic degenerative disc diseases. Traumatic intradural lumbar disc herniations are even rarer. A 52-year-old man visited our emergency center with numbness in his left calf and ankle after falling accident. Initial impression by radiologic findings was a spinal subdural hematoma at the L1 level. A follow up image two weeks later, however, did not demonstrate any interval change. The patient was decided to have an operation. In operative findings, a ruptured disc particle penetrating the ventral and dorsal dura was indentified after laminectomy. It was assumed to be a traumatic outcome not a degenerative change. PMID:24757484

Lee, Hyun-Woo

2013-01-01

19

The Far Lateral Approach to Lumbar Disc Herniations  

Microsoft Academic Search

\\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

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

20

Spontaneous Intracranial Hypotension Secondary to Lumbar Disc Herniation  

PubMed Central

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

Kim, Kyoung-Tae

2010-01-01

21

Relationship between physical work load and lumbar disc herniation.  

PubMed

Lumbar disc herniation (LDH) is a disabling problem. This retrospective case control study was done to evaluate the possible relevance of physical work load with Lumbar Disc Herniation. We have performed this study in the Spinal Surgery Unit of Department of Orthopaedic Surgery at BSMMU, Dhaka from July 2007 to June 2010 where 200 cases with Lumbar Disc Herniation and 200 control subjects matched by age, gender and area of residence were taken and analyzed. Chi-square test was computed for sex, area of residence, type of physical work and effort at work, whereas Odds ratio was computed for physical work load, stress at work and daily working period. The highest odds ratio (OR) was with the physical work load (OR: 03.48, CI: 01.84-06.59), hard work (OR: 03.14, CI: 01.74-05.65) and working period of >8 hours (OR: 01.34, CI: 0.75-02.38). Odds ratio for heavy load carrying at work was 03.48 and less job satisfaction or stress at work was 02.45. There was a statistically significant positive association between cumulative exposure of physical work load and lumbar disc herniation indicating an increased occurrence of herniation in heavy physical work load and occupation requiring harder efforts. PMID:23982545

Ahsan, M K; Matin, T; Ali, M I; Ali, M Y; Awwal, M A; Sakeb, N

2013-07-01

22

Back extensor muscle fatigue in patients with lumbar disc herniation  

Microsoft Academic Search

We investigated back muscle fatigue and endurance in patients with lumbar disc herniation before and after surgery, and established the degree of association between perceived fatigue and objectively measured fatigue. Additionally, the relationships between muscle fatigue and endurance time on the one hand, and activity, participation, self-efficacy and health on the other, were investigated to clarify the grades of association

Åsa Dedering; Karin Harms-Ringdahl; Gunnar Nèmeth

2006-01-01

23

Upper Lumbar Disc Herniation Presenting as Acute Abdomen  

Microsoft Academic Search

A woman presenting with severe right lower quadrant (RLQ) abdominal pain is presented here. She was evaluated for all usual cause of such pain. Laboratory tests and abdominal and pelvic sonograp hy was normal. MRI revealed L1-L2 disc herniation.

Mahmoud Reza Khalatbari; Seyed Taha Yahyavi; Hamid Borghei

24

Treatment of lumbar disc herniation by percutaneous laser disc decompression (PLDD) and modified PLDD  

NASA Astrophysics Data System (ADS)

Objective: To study the micro-invasive operative method and to compare the effect of treatment of PLDD and modified PLDD for Lumbar Disc Herniation. Method: Vaporized part of the nucleus pulposus in single or multiple point after acupuncture into lumbar disc, to reach the purpose of the decompression of the lumbar disc. Result: Among the 19 cases of the regular PLDD group, the excellent and good rate was 63.2%, and among the 40 cases of the modified PLDD group, the excellent and good rate was 82.5%. Conclusion: The modified PLDD has good effect on the treatment for lumbar disc herniation.

Chi, Xiao fei; Li, Hong zhi; Wu, Ru zhou; Sui, Yun xian

2005-07-01

25

High degree of kinesiophobia after lumbar disc herniation surgery  

PubMed Central

Background and purpose Several studies have investigated outcomes after disc surgery. However, the occurrence of kinesiophobia has not been investigated previously in patients after disc herniation surgery. In this cross-sectional study, we investigated kinesiophobia in patients who had been treated surgically for lumbar disc herniation, and we related the results to established outcome measures. Patients and methods 10–34 months after surgery, questionnaires were sent to 97 patients who had undergone standardized open discectomy. Outcome measures included Tampa scale for kinesiophobia (TSK); Oswestry disability index (ODI); European quality of life in 5 dimensions (EQ-5D); visual analog scale (VAS) for leg and back pain, work disability, and patient satisfaction; Zung self-rating depression scale (ZDS); pain catastrophizing scale (PCS); and a self-efficacy scale (SES). Results 36 of 80 patients reported having kinesiophobia. There were statistically significant differences in ODI, EQ-5D, VAS leg and back pain, ZDS, PCS, and SES between patients with and without kinesiophobia. Interpretation Half of the patients suffered from kinesiophobia 10–34 months after surgery for disc herniation. These patients were more disabled, had more pain, more catastrophizing thoughts, more symptoms of depression, lower self-efficacy, and poorer health-related quality of life than patients without kinesiophobia. PMID:22066555

2011-01-01

26

Brown-Sequard syndrome revealing intradural thoracic disc herniation  

Microsoft Academic Search

Brown-Sequard syndrome (BSS) is a rare form of severe myelopathy characterised by a clinical picture reflecting hemisection\\u000a of the spinal cord. This syndrome is mostly due to a penetrating injury to the spine but many other non-traumatic causes have\\u000a been described. Intradural thoracic disc herniation (TDH) is one of the rare aetiologies of this syndrome. Despite progress\\u000a in imaging techniques,

S. Diabira; P.-L. Henaux; L. Riffaud; A. Hamlat; G. Brassier; X. Morandi

2011-01-01

27

Herniated Thoracic Discs Mimic Cardiac Disease: Three Case Reports  

Microsoft Academic Search

Summary  ?The authors report three patients (two males and one female) with herniated thoracic discs whose symptoms mimicked cardiac\\u000a disease (severe intense stabbing pain beginning in the back and radiating to the lateral wall of the chest). They were evaluated\\u000a for cardiac disease and angina, but the workup of the heart was negative. Magnetic resonance imaging and computed tomography\\u000a myelography revealed

M. A. Eleraky; P. J. Apostolides; C. A. Dickman; V. K. H. Sonntag

1998-01-01

28

Percutaneous cervical nucleoplasty in the treatment of cervical disc herniation  

PubMed Central

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) ?11° or horizontal displacement (HD) ?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

Li, Jian; Zhang, Zai-Heng

2008-01-01

29

Changes in disc herniation after CT-guided Percutaneous Laser Disc Decompression (PLDD): MR findings  

NASA Astrophysics Data System (ADS)

The aim of Percutaneous Laser Disc Decompression (PLDD) is to vaporize a small portion of the nucleus pulposus. Clinical efficacy of this technique is largely proven. However, time-evolution of intervertebral disc and its hernia after PLDD is not known. This study analyses changes in disc herniation and its native intervertebral disc at a mean follow-up of 7.5 months after PLDD in asymptomatic patients. Main observations at MRI are appearance of a high signal on T2WI in the hernia in 59%, shrinking of the hernia in 66% and overall stability of disc height.

Brat, Hugues G.; Bouziane, Tarik; Lambert, Jean; Divano, Luisa

2004-09-01

30

Symptomatic disc herniation and serum lipid levels  

Microsoft Academic Search

Insufficient blood supply to the intervertebral disc (IVD) has been proposed to play a role as causative factor in IVD degeneration.\\u000a There is an association between IVD diseases and increased risk of dying of ischaemic heart disease. Obesity and tobacco are\\u000a potential risk factors for degenerative IVD disease. High blood cholesterol and triglycerides serum levels are risk factors\\u000a for atherosclerosis,

Umile Giuseppe Longo; Luca Denaro; Filippo Spiezia; Francisco Forriol; Nicola Maffulli; Vincenzo Denaro

31

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

Microsoft Academic Search

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

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

32

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

Microsoft Academic Search

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

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

33

Composite Features for Automatic Diagnosis of Intervertebral Disc Herniation from Lumbar MRI  

E-print Network

of the spinal column that provide body flexi- bility. Discs in the lumbar spine (lower-back) are composed% of herniation occurs in the lumbar and lumbosacral regions of the spine [2]; hence we are motivated to developComposite Features for Automatic Diagnosis of Intervertebral Disc Herniation from Lumbar MRI

Chaudhary, Vipin

34

Adolescent lumbar disc herniation in a Tae Kwon Do martial artist: a case report  

PubMed Central

Lumbar disc herniations are rare in children. The etiology and clinical picture may be different in children than in adults. Conservative management is the treatment of choice. Tae Kwon Do is a Korean martial art which is notorious for its high fast kicks. Tae Kwon Do will be an official Olympic sport in the year 2000. Low back pain is occasionally reported by Tae Kwon Do athletes but there are no reported cases in the literature on disc herniation in a Tae Kwon Do athlete. A case report is presented to illustrate clinical presentation, diagnosis, radiological assessment and conservative management of lumbar disc herniation in children. ImagesFigure 1Figure 2

Kazemi, Mohsen

1999-01-01

35

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

PubMed Central

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.

?brahimo?lu, Muhammet

2015-01-01

36

Lumbar Disc Herniations 'To Operate or Not' Patient Selection and Timing of Surgery  

PubMed Central

At times lumbar disc herniations present a quandary to the spine surgeon in regards to the most appropriate intervention and a need to optimize medical and surgical therapies. We discuss a case of ours and our experience in treating this common spinal pathology, along with a commentary on the article published by Kim et al. entitled 'Spontaneous regression of extruded lumbar disc herniation: three cases report in Korean J Spine. 2013 Jun;10(2):78-81.' PMID:25620990

Kamian, Kambiz

2014-01-01

37

Surgery versus conservative management of sciatica due to a lumbar herniated disc: a systematic review  

Microsoft Academic Search

The effectiveness of surgery in patients with sciatica due to lumbar disc herniations is not without dispute. The goal of\\u000a this study was to assess the effects of surgery versus conservative therapy (including epidural injections) for patients with\\u000a sciatica due to lumbar disc herniation. A comprehensive search was conducted in MEDLINE, EMBASE, CINAHL, CENTRAL, and PEDro\\u000a up to October 2009.

Wilco C. H. JacobsMaurits; Maurits van Tulder; Mark Arts; Sidney M. Rubinstein; Marienke van Middelkoop; Raymond Ostelo; Arianne Verhagen; Bart Koes; Wilco C. Peul

2011-01-01

38

Diagnosis of disc herniation based on classifiers and features generated from spine MR images  

NASA Astrophysics Data System (ADS)

In recent years the demand for an automated method for diagnosis of disc abnormalities has grown as more patients suffer from lumbar disorders and radiologists have to treat more patients reliably in a limited amount of time. In this paper, we propose and compare several classifiers that diagnose disc herniation, one of the common problems of the lumbar spine, based on lumbar MR images. Experimental results on a limited data set of 68 clinical cases with 340 lumbar discs show that our classifiers can diagnose disc herniation with 97% accuracy.

Koh, Jaehan; Chaudhary, Vipin; Dhillon, Gurmeet

2010-03-01

39

Lumbar disc herniation with contralateral radiculopathy: do we neglect the epidural fat?  

PubMed

Lumbar disc herniation (LDH) is the most common cause of radiculopathy, whose pathological entity underlying nerve root compression is usually on the same side as the symptoms. However, LDH causing contralateral radiculopathy are sometimes encountered by pain physicians. There have been tremendous developmens in the treatment options for LDH; the situation of LDH causing contralateral radiculopathy is indeed a dilemma for some pain physicians. We will report a case of a patient with a L4-5 disc herniation whose left herniated disc caused radiculopathy on the right side. After a percutaneous lumbar endoscopic discectomy via the side ipsilateral to the symptomatic side, this case obtained a significant symptom remission. The migrated epidural fat is discussed as a cause of associated contralateral neurological deficit. Only via a surgical approach ipsilateral to the herniated side, could there be a clinical improvement postoperatively. PMID:25794228

Yang, Jun-Song; Zhang, Dong-Jie; Hao, Ding-Jun

2015-01-01

40

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

PubMed Central

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

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

2015-01-01

41

[A case of thoracic disc herniation with sudden onset paraplegia on toilet straining: case report].  

PubMed

Thoracic disc herniation is less common rather than cervical or lumbar herniation. Cases of sudden onset without trauma are especially rare. Generally, the neurological onset of disc herniation is caused by mechanical cord compression due to a protruded disc, and its onset is usually gradual. Ischemia is also considered as a factor of neurological onset. We report a case of a 78-year-old male with sudden paraplegia while straining at the toilet. T2 weighted MR image on admission showed mild disc protrusion at the level of Th8-9 and intramedullary high signal intensity below the Th8-9 level. We speculate that Valsalva-like maneuver had led to the congestion of vertebral venous plexus or compression of the anterior spinal artery, and spinal ischemia occurred. PMID:14719443

Yano, Shunsuke; Hida, Kazutoshi; Seki, Toshitaka; Iwasaki, Yoshinobu; Akino, Minoru; Saitou, Hisatoshi

2003-12-01

42

Simultaneous occurrence of herniated disc and mesothelial cyst in a 16-year-old male  

Microsoft Academic Search

The unusual, simultaneous occurrence of both a herniated disc and an intraspinal mesothelial cyst in an adolescent is reported. The patient was a 16-year-old white male who presented with sciatic pain in his left lower extremity. Myelography revealed evidence of a left L4–5 discal herniation, and a L5–S3 midline sacral lesion that proved to be a mesothelial cyst.

Nancy E. Epstein; Joseph A. Epstein; Robert Gould; Roger Hyman

1986-01-01

43

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

PubMed Central

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

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

2010-01-01

44

Five and Ten Year Follow-up on Intradiscal Ozone Injection for Disc Herniation  

PubMed Central

Background Disc herniation is the most common cause for spinal surgery and many clinicians employ epidural steroid injections with limited success. Intradiscal injection of ozone gas has been used as an alternative to epidural steroids and surgical discectomy. Early results are positive but long-term data are limited. Methods One hundred and eight patients with confirmed contiguous disc herniation were treated with intradiscal injection of ozone in 2002-2003. One-hundred seven patients were available for telephone follow-up at 5 years. Sixty patients were available for a similar telephone follow-up at ten years. Patients were asked to describe their clinical outcome since the injection. Surgical events were documented. MRI images were reviewed to assess the reduction in disc herniation at six months. Results MRI films demonstrated a consistent reduction in the size of the disc herniation. Seventy-nine percent of patients had a reduction in herniation volume and the average reduction was 56%. There were 19 patients that ultimately had surgery and 12 of them occurred in the first six months after injection. One of these 12 was due to surgery at another level. Two surgeries involved an interspinous spacer indicated by stenosis or DDD. All other surgeries were discectomies. Of the patients that avoided surgery 82% were improved at 5 years and 88% were improved at 10 years. Other than subsequent surgeries, no spine-related complications were experienced. Conclusions/Level of Evidence We conclude that ozone is safe and effective in approximately 75% of patients with disc herniation and the benefit is maintained through ten years. This is a retrospective review and randomized trials are needed. Clinical Relevance Intradiscal ozone injection may enable patients to address their pain without multiple epidural injections and surgery. The benefit of ozone is durable and does not preclude future surgical options. The risk reward profile for this treatment is favorable. PMID:25694935

Buric, Josip; Rigobello, Luca; Hooper, David

2014-01-01

45

Plasma disc decompression for contained cervical disc herniation: a randomized, controlled trial  

PubMed Central

Prospective case series studies have shown that plasma disc decompression (PDD) using the COBLATION SpineWand device (ArthroCare Corporation, Austin, TX) is effective for decompressing the disc nucleus in symptomatic contained cervical disc herniations. This prospective, randomized controlled clinical trial was conducted to evaluate the clinical outcomes of percutaneous PDD as compared to conservative care (CC) through 1 year. Patients (n = 115) had neck/arm pain >50 on the visual analog scale (VAS) pain scale and had failed at least 30 days of failed CC. Patients were randomly assigned to receive either PDD (n = 62) or CC (n = 58). Clinical outcome was determined by VAS pain score, neck disability index (NDI) score, and SF-36 health survey, collected at 6 weeks, 3 months, 6 months, and 1 year. The PDD group had significantly lower VAS pain scores at all follow-up time points (PDD vs. CC: 6 weeks, ?46.87 ± 2.71 vs. ?15.26 ± 1.97; 3 months, ?53.16 ± 2.74 vs. ?30.45 ± 2.59; 6 months, ?56.22 ± 2.63 vs. ?40.26 ± 2.56; 1 year, ?65.73 ± 2.24 vs. ?36.45 ± 2.86; GEE, P < 0.0001). PDD patients also had significant NDI score improvement over baseline when compared to CC patients at the 6 weeks (PDD vs. CC: ?9.15 ± 1.06 vs. ?4.61 ± 0.53, P < 0.0001) and 1 year (PDD vs. CC: ?16.70 ± 0.29 vs. ?12.40 ± 1.26, P = 0.005) follow-ups. PDD patients showed statistically significant improvement over baseline in SF-36 physical component summary scores when compared to CC patients at 6 weeks and 1 year (PDD vs. CC: 8.86 + 8.04 vs. 4.24 ± 3.79, P = 0.0004; 17.64 ± 10.37 vs. 10.50 ± 10.6, P = 0.0003, respectively). In patients who had neck/arm pain due to a contained cervical disc herniation, PDD was associated with significantly better clinical outcomes than a CC regimen. At 1 year, CC patients appeared to suffer a “relapse, showing signs of decline in most measurements, whereas PDD patients showed continued stable improvement. PMID:19902277

Nardi, Pier Vittorio

2009-01-01

46

Clinical Outcomes of Percutaneous Plasma Disc Coagulation Therapy for Lumbar Herniated Disc Diseases  

PubMed Central

Objective This is prospective study of clinical outcomes of percutaneous plasma disc coagulation Therapy (PDCT) in patients with herniated lumbar disc disease (HLD) to evaluate the safety and efficacy in its clinical application and usefulness as a reliable alternative to microscopic discectomy. Methods Forty-six patients were enrolled in this study from April 2006 to June 2010. All patients had one-level HLD. Disc degeneration was graded on routine T2-weighted magnetic resonance Image (MRI) using the Pfirrmann's grading system and all index levels were grade 3 and grade 4. Indications for surgery were radiculopathy caused by disc protrusion with soft consistency. MRI was done at one month after the procedure in all patients to check post-PDCT change. The clinical outcomes were evaluated using Visual Analog Scales (VAS) score and MacNab's criteria. Results This study was approved by the Institutional Review Board of our institution. The age of the study population ranged from 16 to 59 years with a mean age of 37.2 years. There were 29 males and 17 females in this study. The mean period of clinical follow-up was 21 months. The average preoperative VAS score for radiculopathy was 7.4±1.4, while the final follow-up VAS score was 1.4±0.7 (p<0.001). In MacNab's criteria, 41 patients (89.1%) had achieved favorable improvement (excellent and good) until later follow-up. There were one patient from infection and two patients who needed to convert to open discectomy. Conclusion PDCT is a safe and efficient treatment modality in a selective patient with HLD. PMID:22396836

Kim, Sung Chul; Cho, Ki Hong

2012-01-01

47

[New aspects in the treatment of disc herniation in the dog].  

PubMed

Disc herniation is one of the main research topics at the Tierspital Berne. In this review article about canine disc disease, results from recent clinical research are presented and integrated to the actual knowledge about the disease. These new results deal mainly with neurosurgery/neuroradiology and especially focus on therapeutic value of commonly used treatment methods (hemilaminectomy, fenestration, durotomy, lateral corpectomy) in order to further improve therapeutical results in future. PMID:20235010

Forterre, F; Lang, J

2010-03-01

48

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

Microsoft Academic Search

Lumbar disc herniation (LDH) is a common disorder among adults with degenerated lumbar intervertebral discs. However, its\\u000a occurrence in childhood and adolescence is much less frequent mostly because children and adolescents tend to have a healthier\\u000a lumbar spine as compared with adults. This difference indicates that children and adolescents are far from being just little\\u000a adults. Over the years, there

Lei Dang; Zhongjun Liu

2010-01-01

49

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

PubMed

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

Nie, Hong-Fei; Liu, Kai-Xuan

2013-01-01

50

Does Duration of Preoperative Sciatica Impact Surgical Outcomes in Patients with Lumbar Disc Herniation?  

PubMed Central

Background. In lumbar disc herniation, most authors recommend nonoperative treatment for the first few weeks of presentation, but what about the upper limit of this golden period? The aim of this study is to assess the effect of preoperative sciatica duration on surgical outcome of lumbar disc herniation. Methods. We retrospectively evaluated 240 patients (124 males and 116 females) with a mean age of 36.4 ± 5.9 years (range 16 to 63) surgically treated due to primary stable L4-L5 disc herniation. The patients were placed into two groups: with more and less than 12-month duration of preoperative sciatalgia. Disability and pain were measured by Oswestry Disability Index (ODI) and Visual Analogue Scale (VAS). Wilcoxon test and Mann-Whitney U test were used for statistical analysis. Results. Total mean duration of preoperative sciatalgia and follow-up period were 13.3 months (range 2 to 65) and 33.7 ± 5.1 months (range 24 to 72), respectively. Comparison between the groups showed that duration of preoperative sciatalgia either less or more than 12 months did not affect the surgical outcomes significantly. Conclusions. More or less than 12-month duration of preoperative sciatalgia may not affect the surgical outcomes of simple lumbar disc herniation in the patients undergoing discectomy. PMID:24616807

Ghayem Hasankhani, Ebrahim; Khanzadeh, Reza

2014-01-01

51

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

PubMed Central

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

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

2013-01-01

52

Diagnosis of Disc Herniation Based on Classifiers and Features Generated from Spine MR Images  

E-print Network

, one of the common problems of the lumbar spine, based on lumbar MR images. Experimental resultsDiagnosis of Disc Herniation Based on Classifiers and Features Generated from Spine MR Images patients suffer from lumbar disorders and radiologists have to treat more patients reliably in a limited

Chaudhary, Vipin

53

Nucleus pulposus cells derived IGF-1 and MCP-1 enhance osteoclastogenesis and vertebrae disruption in lumbar disc herniation  

PubMed Central

Study design: Chronic strained lumbar disc herniation (LDH) cases were classified into bulging LDH, herniated LDH and prolapse LDH types according to imaging examination, and vertebrae disruptions were evaluated. Cytokines derived from the nucleus pulposus cells were detected, and their effects on osteoclastogenesis, as well as the mechanisms involved, were studied via an in vitro osteoclast differentiation system. Objective: To clarify the mechanisms of lumbar vertebrae resorption induced by lumbar herniation. Summary and background data: Chronic strained lumbar disc herniation induced vertebrae erosion exacerbates quality of patients’ life and clinical outcome. Although nucleus pulposus cells derived cytokines were reported to play an important role in this pathogenesis, the fundamental mechanisms underlying this process are still unclear. Methods: Chronic strained lumbar disc herniation patients were diagnosed with CT scan and T2-weighted magnetic resonance imaging. RNA was extracted from 192 surgical specimens of the herniated lumbar disc and 29 surgical excisions of the lumbar disc from spinal injury patients. The expressions of osteoclastogenesis related cytokines and chemokines were examined using real time PCR. Monocytes were induced into osteoclast with M-CSF and RANKL in vitro, while the IGF-1 and MCP-1 were added into the differentiation procedure in order to evaluate the effects and explore the molecular mechanisms. Results: Vertebrae erosion had a positive relationship with lumbar disc herniation severity types. In all of the osteoclastogenesis related cytokines, the IGF-1 and MCP-1 were the most highly expressed in the nucleus pulposus cells. IGF-1 enhances activation of NF-kB signaling directly, but MCP-1 upregulated the expression of RANK, so that enhanced cellular sensitivity to RANKL resulted in increasing osteoclastogenesis and activity. Conclusion: Lumbar herniation induced overexpression of IGF-1 and MCP-1 in nucleus pulposus cells aggravated vertebral erosions. Hence, this study suggests that targeting osteoclastogenesis related cytokines has potential clinical significance in the treatment of lumbar disc herniation patients. PMID:25674216

Zhu, Zhongjiao; Huang, Peng; Chong, Yanxue; George, Suraj K; Wen, Bingtao; Han, Na; Liu, Zhiqiang; Kang, Lixin; Lin, Nie

2014-01-01

54

Retrolisthesis and lumbar disc herniation: a postoperative assessment of patient function  

PubMed Central

BACKGROUND CONTEXT The presence of retrolisthesis has been associated with the degenerative changes of the lumbar spine. However, retrolisthesis in patients with L5–S1 disc herniation has not been shown to have a significant relationship with worse baseline pain or function. Whether it can affect the outcomes after discectomy, is yet to be established. PURPOSE The purpose of this study was to determine the relationship between retrolisthesis (alone or in combination with other degenerative conditions) and postoperative low back pain, physical function, and quality of life. This study was intended to be a follow-up to a previous investigation that looked at the preoperative assessment of patient function in those with retrolisthesis and lumbar disc herniation. STUDY DESIGN Cross-sectional study. PATIENT SAMPLE Patients enrolled in SPORT (Spine Patient Outcomes Research Trial) who had undergone L5–S1 discectomy and had a complete magnetic resonance imaging scan available for review (n=125). Individuals with anterolisthesis were excluded. OUTCOME MEASURES Time-weighted averages over 4 years for the Short Form (SF)-36 bodily pain scale, SF-36 physical function scale, Oswestry Disability Index (ODI), and Sciatica Bothersomeness Index (SBI). METHODS Retrolisthesis was defined as a posterior subluxation of 8% or more. Disc degeneration was defined as any loss of disc signal on T2 imaging. Modic changes were graded 1 to 3 and collectively classified as vertebral end plate degenerative changes. The presence of facet arthropathy and ligamentum flavum hypertrophy was classified jointly as posterior degenerative changes. Longitudinal regression models were used to compare the time-weighted outcomes over 4 years. RESULTS Patients with retrolisthesis did significantly worse with regard to bodily pain and physical function over 4 years. However, there were no significant differences in terms of ODI or SBI. Similarly, retrolisthesis was not a significant factor in the operative time, blood loss, lengths of stay, complications, rate of additional spine surgeries, or recurrent disc herniations. Disc degeneration, modic changes, and posterior degenerative changes did not affect the outcomes. CONCLUSIONS Although retrolisthesis in patients with L5–S1 disc herniation did not affect the baseline pain or function, postoperative outcomes appeared to be somewhat worse. It is possible that the contribution of pain or dysfunction related to retrolisthesis became more evident after removal of the disc herniation. PMID:23201024

Kang, Kevin K.; Shen, Michael S.; Zhao, Wenyan; Lurie, Jon D.; Razi, Afshin E.

2013-01-01

55

Outcome of nucleoplasty in patients with radicular pain due to lumbar intervertebral disc herniation  

PubMed Central

Background: Nucleoplasty (percutaneous lumbar disc decompression) is a minimally invasive procedure that utilizes radiofrequency energy as a treatment for symptomatic lumbar disc herniation, against open microdiscectomy, which would be the mainstay treatment modality. The literature reports a favorable outcome in up to 77% of patients at 6 months. Aim: To evaluate the effectiveness of nucleoplasty in the management of discogenic radicular pain. Materials and Methods: The medical notes of 33 patients, admitted for nucleoplasty between June 2006 and September 2007, were reviewed retrospectively. All had radicular pain, and contained herniated disc as seen on magnetic resonance imaging (MRI) of lumbosacral spine. Patients were followed up at 1 and 3 months post-procedure. The outcome measures employed in this study were satisfaction with symptoms and self-reported improvement. Results: Thirty-three cases were examined (18 males and 15 females). Twenty-seven procedures were performed with no complications and six were abandoned due to anatomical reasons. There were 18 and 15 cases of disc herniation at L5/S1 and L4/5 levels, respectively. Four weeks following the procedure, 13 patients reported improvement in symptoms, and 14 remained symptomatically the same and subsequently had open microdiscectomy. Conclusion: Nucleoplasty has been shown to be a safe and minimal-access procedure. Less than half of our selected cohort of patients reported symptomatic improvement at 1-month follow-up. We no longer offer this procedure to our patients. Possible reasons are discussed. PMID:23633860

Ogbonnaya, Sunny; Kaliaperumal, Chandrasekaran; Qassim, Abdulla; O’Sullivan, Michael

2013-01-01

56

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

PubMed Central

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

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

2015-01-01

57

Clinical outcomes after posterior dynamic transpedicular stabilization with limited lumbar discectomy: Carragee classification system for lumbar disc herniations  

PubMed Central

Background The observed rate of recurrent disc herniation after limited posterior lumbar discectomy is highest in patients with posterior wide annular defects, according to the Carragee classification of type II (fragment-defect) disc hernia. Although the recurrent herniation rate is lower in both type III (fragment-contained) and type IV (no fragment-contained) patients, recurrent persistent sciatica is observed in both groups. A higher rate of recurrent disc herniation and sciatica was observed in all 3 groups in comparison to patients with type I (fragment-fissure) disc hernia. Methods In total, 40 single-level lumbar disc herniation cases were treated with limited posterior lumbar microdiscectomy and posterior dynamic stabilization. The mean follow-up period was 32.75 months. Cases were selected after preoperative magnetic resonance imaging and intraoperative observation. We used the Carragee classification system in this study and excluded Carragee type I (fragment-fissure) disc herniations. Clinical results were evaluated with visual analog scale scores and Oswestry scores. Patients’ reherniation rates and clinical results were evaluated and recorded at 3, 12, and 24 months postoperatively. Results The most common herniation type in our study was type III (fragment-contained), with 45% frequency. The frequency of fragment-defects was 25%, and the frequency of no fragment-contained defects was 30%. The perioperative complications observed were as follows: 1 patient had bladder retention that required catheterization, 1 patient had a superficial wound infection, and 1 patient had a malpositioned transpedicular screw. The malpositioned screw was corrected with a second operation, performed 1 month after the first. Recurrent disc herniation was not observed during the follow-up period. Conclusions We observed that performing discectomy with posterior dynamic stabilization decreased the risk of recurrent disc herniations in Carragee type II, III, and IV groups, which had increased reherniation and persistent/continuous sciatica after limited lumbar microdiscectomy. Moreover, after 2 years’ follow-up, we obtained improved clinical results.

Kaner, Tuncay; Sasani, Mehdi; Oktenoglu, Tunc; Cosar, Murat; Ozer, Ali Fahir

2010-01-01

58

A History of Lumbar Disc Herniation From Hippocrates to the 1990s.  

PubMed

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

Truumees, Eeric

2014-04-22

59

Adjacent Lumbar Disc Herniation after Lumbar Short Spinal Fusion  

PubMed Central

A 70-year-old outpatient presented with a chief complaint of sudden left leg motor weakness and sensory disturbance. He had undergone L4/5 posterior interbody fusion with L3–5 posterior fusions for spondylolisthesis 3 years prior, and the screws were removed 1 year later. He has been followed up for 3 years, and there had been no adjacent segment problems before this presentation. Lumbar magnetic resonance imaging (MRI) showed a large L2/3 disc hernia descending to the L3/4 level. Compared to the initial MRI, this hernia occurred in an “intact” disc among multilevel severely degenerated discs. Right leg paresis and bladder dysfunction appeared a few days after admission. Microscopic lumbar disc herniotomy was performed. The right leg motor weakness improved just after the operation, but the moderate left leg motor weakness and difficulty in urination persisted. PMID:25276453

Iwatsuki, Koichi; Ohnishi, Yu-ichiro; Yoshimine, Toshiki

2014-01-01

60

Adjacent lumbar disc herniation after lumbar short spinal fusion.  

PubMed

A 70-year-old outpatient presented with a chief complaint of sudden left leg motor weakness and sensory disturbance. He had undergone L4/5 posterior interbody fusion with L3-5 posterior fusions for spondylolisthesis 3 years prior, and the screws were removed 1 year later. He has been followed up for 3 years, and there had been no adjacent segment problems before this presentation. Lumbar magnetic resonance imaging (MRI) showed a large L2/3 disc hernia descending to the L3/4 level. Compared to the initial MRI, this hernia occurred in an "intact" disc among multilevel severely degenerated discs. Right leg paresis and bladder dysfunction appeared a few days after admission. Microscopic lumbar disc herniotomy was performed. The right leg motor weakness improved just after the operation, but the moderate left leg motor weakness and difficulty in urination persisted. PMID:25276453

Ninomiya, Koshi; Iwatsuki, Koichi; Ohnishi, Yu-Ichiro; Ohkawa, Toshika; Yoshimine, Toshiki

2014-01-01

61

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

PubMed Central

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

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

2009-01-01

62

Using geographical information system for spatial evaluation of canine extruded disc herniation.  

PubMed

Disc herniation is one of the most common pathologies of the vertebral column in dogs. The aim of this study was to develop a geographical information system (GIS)-based vertebral canal (VC) map useful for spatial evaluation of extruded disc herniation (EDH) in dogs. ArcGIS® was used to create two-dimensional and three-dimensional maps, in which the VC surface is divided into polygons by lines representing latitude and longitude. Actual locations and directions of the herniated disc material were assessed by a series of 142 computer tomographies of dogs collected between 2005 and 2013. Most EDHs were located on the cervical and transitional regions (thoraco-lumbar and lumbo-sacral) and shown at the level of the ventro- cranial and ventro-central polygons created. Choropleth maps, highlighting the distribution and the location/direction patterns of the EDHs throughout the VC, were produced based on the frequency of the ailment. GIS proved to be a valuable tool in analysing EDH in dogs. Further studies are required for biomechanical analysis of EDH patterns. PMID:25545938

Daraban, Constantin; Murino, Carla; Marzatico, Giuseppe; Mennonna, Giuseppina; Fatone, Gerardo; Auletta, Luigi; Miceli, Fabiana; Vulpe, Vasile; Meomartino, Leonardo

2014-11-01

63

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

PubMed Central

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

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

2014-01-01

64

The clinical study of percutaneous disc decompression of treating herniation of cervical disc with Nd:YAG laser  

NASA Astrophysics Data System (ADS)

Objective: The possibility of PLDD (percutaneous laser disc decompression) and an ideal non-operative method which is long everlasting effect for PLDD was investigated. Methods: 159 patients of Cervical Disc Herniation with PLDD were studied. All the herniated discs were irradiated with 10­15J/S Nd:YAG laser quantum through optical-fiber under the supervision of C-arm X-ray. Results: All the patients were followed and reexamined CT or MRI after one to six months of PLDD. The result of cured (67.92%), excellent (24.53%), moderation (5.66%), non-effect (1.88%) was got. The excellent rate was 88.24%. The effective rate was 97.65%. Non-effective rate was 2.35%. Conclusion: When irradiated with Nd:YAG laser, the nucleus pulposus was vapouring, charring and coagulating. The volume and inner-pressure of the disc decreased. So the symptoms and signs improved. The main value of this methods were micro-damage, non-operation, no bleeding, no bone injury, good therapy effect, quick recovery, lesser pain, safety and excellent long everlasting effect. It is an ideal non-operative method of treating PLDD.

Zhang, Dianxue; Cheng, Hefu; Wang, Jindong

2005-07-01

65

Degenerative disc disease of herniated intervertebral discs is associated with extracellular matrix remodeling, vimentin-positive cells and cell death.  

PubMed

We studied patients with degenerative disc disease (DDD) to demonstrate that i) remodeling of the extracellular matrix (ECM) in the intervertebral disc (IVD), particularly the elastic fiber system, of subjects with herniated discs is dysregulated and that ii) it is accompanied by accelerated elastin degradation due to increased expression of matrix metalloprotease-9 (MMP-9). Moreover we wanted to obtain a deeper insight into the pathogenesis of DDD through the study of ECM calcification, DNA fragmentation using TUNEL analysis, BAX, bcl-2 and vimentin immunopositive cells. We studied herniated discs from patients of three age groups (group 1=30-40 years; group 2=40-50 years; and group 3=50-65 years) to evaluate the oxytalan fiber systemMMP-9, apoptosis and vimentin immunopositive cells. The results demonstrated the presence of oxytalan fibers in the annulus fibrosus (AF) and the nucleus pulposus (NP) of herniated discs. In the AF oxytalan fibers replaced disrupted mature elastic fibers in calcified areas, while in the NP they were mostly found in nests at the periphery of chondrocytes. MMP-9 was prevalently observed in NP nests above all in group 1 and group 3 discs while group 2 exhibited a lower MMP-9 immunostaining. Activation of the apoptotic process was demonstrated by upregulated BAX expression in group 3. BAX immunopositivity was inversely mirrored by a significant decrease in bcl-2 expression. Intermediate filament protein vimentin was strongly expressed only in group 1 samples. A large number of apoptotic TUNEL+ cells was observed in group 3 specimens. The presence of oxytalan fibers may be the result of a process of incomplete elastogenesis, or a response to mechanical stress trying to functionally replace the lack of elastic fibers. MMP-9 expression seems to relate to disc damage, while chondrocyte BAX upregulation and TUNEL+ cell staining revealed apoptosis activation regardless of patient age. Vimentin immunopositivity was clearly detected in group 1 annulus fibrosus and nucleus pulposus cells. In conclusion, as demonstrated by the vimentin-positive cells, the injured IVD has endogenous resources that can stem the DDD damage, including substitution of damaged elastic fibers by oxytalan fibers. In addition, induction of apoptosis suggests an increased cell turnover in response to repair needs. PMID:21330123

Loreto, Carla; Musumeci, Giuseppe; Castorina, Alessandro; Loreto, Corrado; Martinez, Giuseppa

2011-03-01

66

Acute Paraplegia Secondary to Thoracic Disc Herniation of the Adjacent Segment Following Thoracolumbar Fusion and Instrumentation  

PubMed Central

Proximal junctional disease is a well-recognized postoperative phenomenon in adults who are undergoing long thoracolumbar fusion and instrumentation, and is attributed to increased a junctional stress concentration. In general, the onset of symptoms in these patients is insidious and the disease progresses slowly. We report on a contrary case of rapidly progressing paraplegia secondary to acute disc herniation at the proximal adjacent segment after long posterior thoracolumbar fusion with cement augmentation at the upper instrumented vertebra and the supra-adjacent vertebra. The patient was treated with a discectomy through the costo-transverse approach combined with extension of the posterior instrumentation. The patient's neurological status improved markedly. Stress concentration at the proximal junction disc space may have caused accelerated disc degeneration which in turn lead to this complication. PMID:23508671

Assaker, Richard; Musharrafieh, Ramzi Sharif

2013-01-01

67

Crohn's disease with pelvic abscess appearing as lumbar disc herniation.  

PubMed

Crohn's disease (regional enteritis) is a chronic inflammatory disease of the bowel with well-documented clinical manifestations and complications. This report of a 35-year-old woman with Crohn's disease outlines the clinical presentation and studies illustrating "quiescent" regional enteritis. The patient was treated for one of the complications of this disease entity. She was referred to the orthopedic clinic with symptoms of lumbar disc syndrome, as well as a painful hip. Crohn's disease was diagnosed and assumed to be well controlled. Physical examination revealed a subgluteal abscess, ostensibly caused by Crohn's disease. The abscess fistulized through the greater sciatic notch. The capricious nature of this disease entity is self-evident. PMID:3621717

O'Neil, D J; Harding, D

1987-09-01

68

Herniated Lumbar Disc Combined with Spinal Intradural Extramedullary Cysticercosis  

PubMed Central

Spinal cysticercosis is a very uncommon manifestation of neurocysticercosis which is caused by the larvae of Taenia solium. However, it can develop as a primary infection through blood stream or direct larval migration. It can result in high recurrence and severe neurologic morbidity if not treated appropriately. We report the case of a 43-year-old woman who presented with severe lower back pain and left leg radiating pain in recent 2 weeks. Magnetic resonance image (MRI) of lumbar spine demonstrated extruded disc at the L5-S1 level combined with intradural extramedullary cystic lesion. We performed the open lumbar microdiscectomy (OLM) at L5-S1 on the left with total excision of cystic mass. After surgery, the patient showed an improvement of previous symptoms. Diagnosis was confirmed by histopathological examination as intradural extramedullary cysticercosis. We discuss clinical features, diagnostic screening, and treatment options of spinal cysticercosis. PMID:21430986

Choi, Kyeong Bo; Choi, Won Gyu; Lee, Sang-Ho

2010-01-01

69

A Novel Approach to the Surgical Treatment of Lumbar Disc Herniations: Indications of Simple Discectomy and Posterior Transpedicular Dynamic Stabilization Based on Carragee Classification  

PubMed Central

Surgery of lumbar disc herniation is still a problem since Mixter and Barr. Main trouble is dissatisfaction after the operation. Today there is a debate on surgical or conservative treatment despite spending great effort to provide patients with satisfaction. The main problem is segmental instability, and the minimally invasive approach via microscope or endoscope is not necessarily appropriate solution for all cases. Microsurgery or endoscopy would be appropriate for the treatment of Carragee type I and type III herniations. On the other hand in Carragee type II and type IV herniations that are prone to develop recurrent disc herniation and segmental instability, the minimal invasive techniques might be insufficient to achieve satisfactory results. The posterior transpedicular dynamic stabilization method might be a good solution to prevent or diminish the recurrent disc herniation and development of segmental instability. In this study we present our experience in the surgical treatment of disc herniations. PMID:23653862

Ozer, A. F.; Keskin, F.; Oktenoglu, T.; Suzer, T.; Ataker, Y.; Gomleksiz, C.; Sasani, M.

2013-01-01

70

Assessment of sexual dysfunction before and after surgery for lumbar disc herniation.  

PubMed

Object Sexuality is an important aspect of human life. Sexual activity may be affected in lumbar disc herniation through different mechanisms. The aim of this study is to evaluate patients' sexual problems and sexual behavior patterns before and after surgical treatment of lumbar disc herniation. Methods Forty-three patients were included in the study (mean age 41.4 years). A visual analog scale, the Oswestry Disability Index, the Hospital Anxiety and Depression Scale, and a sexuality assessment questionnaire developed for this study were administered to the patients to evaluate pain and sexual dysfunction. Results Fifty-five percent of the men and 84% of the women reported experiencing sexual problems after the onset of low-back pain. The most common sexual problems were decreased sexual desire (18%) and premature ejaculation together with erectile dysfunction (18%) for the male patients, and decreased sexual desire (47%) for the female patients. The frequency of sexual intercourse before the operation was reduced in 78% of cases compared with the pain-free period. Postoperatively, the patients first attempted sexual intercourse a mean of 26.5 days after surgery. The frequency of intercourse was found to have increased (p = 0.01), while description of any type of sexual problem had decreased (p = 0.005) significantly. Conclusions Lumbar disc herniation has negative effects on sexual life, and not enough attention is given to the patients' sexual problems by the physicians. Decreased sexual desire and decreased sexual intercourse are the most commonly reported problems. Taking time during examination and giving simple recommendations may improve sexuality and life quality of the patients. PMID:21039147

Akba?, Naz B; Dalbayrak, Sedat; Külcü, Duygu G; Yilmaz, Mesut; Yilmaz, Tevfik; Naderi, Sait

2010-11-01

71

Application of Percutaneous Cervical Nucleoplasty Using the Navigable Disc Decompression Device in Patient of Cervical Herniated Intervertebral Disc: A Case Report  

PubMed Central

Recent years, various percutaneous procedures including cervical nucleoplasty have been developed for disc decompressions to relieve radicular pains caused by disc herniations. We report the application of percutaneous cervical nucleoplasty (PCN) by using the navigable disc decompression device in two patients of cervical herniated intervertebral discs (HIVD). A 38-year-old female diagnosed with C4-C5 disc extrusion with bilateral C5 roots impingement received nucleoplasty twice at C4-C5 disc level. After second procedure, her pain was improved from 6-7/10 to 1-2/10 by visual analog scale (VAS). The second case, a 51-year-male was diagnosed with C6-C7 disc extrusion with right C7 roots impingement and received the procedure at C6-C7 disc level. The pain improved from 8/10 to 3-4/10 by VAS. Successfully, we decompressed cervical herniated discs in 2 HIVD patients without major complications. The PCN with the navigable device will be recommended as an alternative treatment method for cervical HIVD. PMID:24236264

Lim, Ji-Hoon; Lee, Hye-Jin

2013-01-01

72

Catabolic cytokine expression in degenerate and herniated human intervertebral discs: IL-1? and TNF? expression profile  

PubMed Central

Low back pain is a common and debilitating disorder. Current evidence implicates intervertebral disc (IVD) degeneration and herniation as major causes, although the pathogenesis is poorly understood. While several cytokines have been implicated in the process of IVD degeneration and herniation, investigations have predominately focused on Interleukin 1 (IL-1) and tumor necrosis factor alpha (TNF?). However, to date no studies have investigated the expression of these cytokines simultaneously in IVD degeneration or herniation, or determined which may be the predominant cytokine associated with these disease states. Using quantitative real time PCR and immunohistochemistry we investigated gene and protein expression for IL-1?, TNF? and their receptors in non-degenerate, degenerate and herniated human IVDs. IL-1? gene expression was observed in a greater proportion of IVDs than TNF? (79% versus 59%). Degenerate and herniated IVDs displayed higher levels of both cytokines than non-degenerate IVDs, although in degenerate IVDs higher levels of IL-1? gene expression (1,300 copies/100 ng cDNA) were observed compared to those of TNF? (250 copies of TNF?/100 ng cDNA). Degenerate IVDs showed ten-fold higher IL-1 receptor gene expression compared to non-degenerate IVDs. In addition, 80% of degenerate IVD cells displayed IL-1 receptor immunopositivity compared to only 30% of cells in non-degenerate IVDs. However, no increase in TNF receptor I gene or protein expression was observed in degenerate or herniated IVDs compared to non-degenerate IVDs. We have demonstrated that although both cytokines are produced by human IVD cells, IL-1? is expressed at higher levels and in more IVDs, particularly in more degenerate IVDs (grades 4 to 12). Importantly, this study has highlighted an increase in gene and protein production for the IL-1 receptor type I but not the TNF receptor type I in degenerate IVDs. The data thus suggest that although both cytokines may be involved in the pathogenesis of IVD degeneration, IL-1 may have a more significant role than TNF?, and thus may be a better target for therapeutic intervention. PMID:17688691

Le Maitre, Christine Lyn; Hoyland, Judith Alison; Freemont, Anthony J

2007-01-01

73

Composite features for automatic diagnosis of intervertebral disc herniation from lumbar MRI.  

PubMed

Lower back pain is widely prevalent in the world today, and the situation is aggravated due to a shortage of radiologists. Intervertebral disc disorders like desiccation, degeneration and herniation are some of the major causes of lower back pain. In this paper, we propose a robust computer-aided herniation diagnosis system for lumbar MRI by first extracting an approximate Region Of Interest (ROI) for each disc and then using a combination of viable features to produce a highly accurate classifier. We describe the extraction of raw, LBP (Local Binary Patterns), Gabor, GLCM (Gray-Level Co-occurrence Matrix), shape, and intensity features from lumbar SPIR T2-weighted MRI and also present a thorough performance comparison of individual and combined features. We perform 5-fold cross validation experiments on 35 cases and report a very high accuracy of 98.29% using a combination of features. Also, combining the desired features and reducing the dimensionality using LDA, we achieve a high sensitivity (true positive rate) of 98.11%. PMID:22255478

Ghosh, Subarna; Alomari, Raja' S; Chaudhary, Vipin; Dhillon, Gurmeet

2011-01-01

74

The implantation of non-cell-based materials to prevent the recurrent disc herniation: an in vivo porcine model using quantitative discomanometry examination  

PubMed Central

Recurrent disc herniation is frequently observed due to leakage of nucleus pulposus through injured anulus fibrosus. There is no effective treatment to prevent recurrent disc herniation yet. In this study, we proposed to implant non-cell-based materials into the porcine disc to stimulate the growth of fibrous tissue and thereby increase the disc functional integrity. The disc herniation was simulated by anular punctures using the spinal needles. Four clinically used implantation materials, i.e., gelfoam, platinum coil, bone cement and tissue glue, were delivered into the discs via percutaneous spinal needles. Two months after the surgery, the swine were killed. The degree of disc integrity of intact, naturally healed and implanted discs, was examined by quantitative discomanometry apparatus. We found the disc injury could not recover after 2 months of healing, and the disc implantation affected the degree of disc integrity. The disc integrity of gelfoam-implanted discs was better than that of coil-, bone cement-, and glue-implanted discs. The implantation of non-cell-based material was proved to be a potentially clinically applicable method to recover the integrity of injured discs and to prevent recurrent disc herniation. PMID:17252217

Wang, Yao-Hung; Kuo, Tzong-Fu

2007-01-01

75

Describing a new syndrome in L5-S1 disc herniation: Sexual and sphincter dysfunction without pain and muscle weakness  

PubMed Central

Context: Little seems to be known about the sexual dysfunction (SD) in lumbar intervertebral disc herniation. Aims: Investigation of sexual and sphincter dysfunction in patient with lumbar disc hernitions. Settings and Design: A retrospective analysis. Materials and Methods: Sexual and sphincter dysfunction in patients admitted with lumbar disc herniations between September 2012-March 2014. Statistical Analysis Used: Statistical analysis was performed using the Predictive Analytics SoftWare (PASW) Statistics 18.0 for Windows (Statistical Package for the Social Sciences, SPSS Inc., Chicago, Illinois). The statistical significance was set at P < 0.05. The Wilcoxon signed ranks test was used to evaluate the difference between patients. Results: Four patients with sexual and sphincter dysfunction were found, including two women and two men, aged between 20 and 52 years. All of them admitted without low back pain. In addition, on neurological examination, reflex and motor deficit were not found. However, almost all patients had perianal sensory deficit and sexual and sphincter dysfunction. Magnetic resonance imaging (MRI) of three patients displayed a large extruded disc fragment at L5-S1 level on the left side. In fourth patient, there were not prominent disc herniations. There was not statistically significant difference between pre-operative and post-operative sexual function, anal-urethral sphincter function, and perianal sensation score. A syndrome in L5-S1 disc herniation with sexual and sphincter dysfunction without pain and muscle weakness was noted. We think that it is crucial for neurosurgeons to early realise that paralysis of the sphincter and sexual dysfunction are possible in patients with lumbar L5-S1 disc disease. Conclusion: A syndrome with perianal sensory deficit, paralysis of the sphincter, and sexual dysfunction may occur in patients with lumbar L5-S1 disc disease. The improvement of perianal sensory deficit after surgery was counteracted by a trend toward disturbed sexual function. Further researches are needed to explore the extent of this problem. PMID:25558144

Akca, Nezih; Ozdemir, Bulent; Kanat, Ayhan; Batcik, Osman Ersagun; Yazar, Ugur; Zorba, Orhan Unal

2014-01-01

76

Nonmedical methods to relieve low back pain caused by lumbar disc herniation: a descriptive study in northeastern Turkey.  

PubMed

Low back pain due to the effects of lumbar disc herniation is a common complaint of patients who often subsequently seek help from medical professionals. It is also a significant health problem which is quite difficult to treat. This descriptive study was conducted to determine nonmedical methods used by patients with lumbar disc herniation to relieve low back pain; the patients' intensity of low back pain when they were admitted to the hospital was also explored. Ninety-two patients with lumbar disc herniation participated in this study, which was carried out at a university hospital in northeastern Turkey. Data were collected using a patient information form and the visual analog scale (VAS). When the patients were admitted to hospital, their mean VAS score was 6.56 ± 2.45. The study results showed that as a first choice nearly all of the patients (94.6%) with lumbar disc herniation preferred consulting with their physicians before to obtain relief for low back pain. However, in addition to seeing their physician, more than one-half of these patients (57.6%) also used nonmedical methods. The primary nonmedical methods were hot/cold compresses, wrapping various substances on the back, and herbal preparations. An increase in pain was noted by 17.0% of patients after using nonmedical methods. Findings indicated that more than two-thirds of patients experienced either no change or an increase in pain after using nonmedical methods to find relief. PMID:24882024

Cilingir, Dilek; Hintistan, Sevilay; Yigitbas, Cagla; Nural, Nesrin

2014-06-01

77

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

Microsoft Academic Search

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

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

78

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

PubMed Central

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

2014-01-01

79

Air Bubbles Mimic Disc Herniation in MRI after Cervical Epidural Block  

PubMed Central

Magnetic resonance image (MRI) is the most sensitive imaging test of the spine in routine clinical practice. Unlike conventional x-ray examinations and computed tomography scans, high-quality magnetic resonance images can be assured only if patients are able to remain perfectly still. However, some patients find it uncomfortable to remain still because of pain. In that condition, interlaminar cervical epidural injections can reduce pain and allow the procedure. When using air with the "loss of resistance" technique in epidural injections to identify the epidural space, there is the possibility of injected excessive air epidurally to mimic a herniated disc. We describe a case report of epidural air artifact in a cervical MRI after cervical epidural injections. PMID:20830267

Shin, Sung Sik; Kim, Jung Ryul; Kim, Dal Yong

2010-01-01

80

Spinal cord injury secondary to cervical disc herniation in ambulatory patients with cerebral palsy.  

PubMed

Early onset of degeneration of the cervical spine and instability due to sustained abnormal tonicity or abnormal movement of the neck are found in patients with cerebral palsy. An unexplained change or deterioration of neurological function in patients with cerebral palsy should merit the consideration of the possibility of cervical myelopathy due to early degeneration or instability of the cervical spine. We describe two patients who had a spinal cord injury due to a cervical disc herniation, one patient was athetoid and the second had spastic diplegia, they both had cerebral palsy. It is not easy to determine whether new neurological symptoms are as a result of the cervical spinal cord disorder. These cases suggest that consideration of a cervical spine disorder with myelopathy is required in the evaluation of patients with cerebral palsy who develop deterioration of neurological function or activities over a short period of time. PMID:9589531

Ko, H Y; Park-Ko, I

1998-04-01

81

Brain herniation  

MedlinePLUS

... herniation; Uncal herniation; Subfalcine herniation; Tonsillar herniation; Herniation - brain ... Brain herniation occurs when something inside the skull produces pressure that moves brain tissues. This is most ...

82

Brown–Sequard syndrome produced by cervical disc herniation with complete neurologic recovery: report of three cases and review of the literature  

Microsoft Academic Search

Study design:Case report.Objective:To report three cases of Brown–Sequard syndrome (BSS) associated with cervical disc herniation.Method:We describe clinical and radiographic review of three patients who presented with BSS caused by cervical disc herniation. Three patients presented with ipsilateral motor weakness and diminished sensation to pain and temperature on the contralateral side. Magnetic resonance images of the cervical spine in all cases,

J-K Lee; Y-S Kim; S-H Kim; Jung-Kil Lee

2007-01-01

83

Structural Brain Alterations in Patients with Lumbar Disc Herniation: A Preliminary Study  

PubMed Central

Chronic pain is one of the most common health complaints in industrial nations. For example, chronic low back pain (cLBP) disables millions of people across the world and generates a tremendous economic burden. While previous studies provided evidence of widespread functional as well as structural brain alterations in chronic pain, little is known about cortical changes in patients suffering from lumbar disc herniation. We investigated morphometric alterations of the gray and white matter of the brain in patients suffering from LDH. The volumes of the gray and white matter of 12 LDH patients were determined in a prospective study and compared to the volumes of healthy controls to distinguish local differences. High-resolution MRI brain images of all participants were performed using a 3 Tesla MRI scanner. Voxel-based morphometry was used to investigate local differences in gray and white matter volume between patients suffering from LDH and healthy controls. LDH patients showed significantly reduced gray matter volume in the right anterolateral prefrontal cortex, the right temporal lobe, the left premotor cortex, the right caudate nucleus, and the right cerebellum as compared to healthy controls. Increased gray matter volume, however, was found in the right dorsal anterior cingulate cortex, the left precuneal cortex, the left fusiform gyrus, and the right brainstem. Additionally, small subcortical decreases of the white matter were found adjacent to the left prefrontal cortex, the right premotor cortex and in the anterior limb of the left internal capsule. We conclude that the lumbar disk herniation can lead to specific local alterations of the gray and white matter in the human brain. The investigation of LDH-induced brain alterations could provide further insight into the underlying nature of the chronification processes and could possibly identify prognostic factors that may improve the conservative as well as the operative treatment of the LDH. PMID:24595036

Luchtmann, Michael; Steinecke, Yvonne; Baecke, Sebastian; Lützkendorf, Ralf; Bernarding, Johannes; Kohl, Jana; Jöllenbeck, Boris; Tempelmann, Claus; Ragert, Patrick; Firsching, Raimund

2014-01-01

84

Eight Year Outcome after Surgery for Lumbar Disc Herniation: A Comparison of Reoperated and not Reoperated Patients  

Microsoft Academic Search

Summary  ?A retrospective study of 211 patients with unilateral sciatica operated on for lumbar disc herniation during 1988 and 1989\\u000a was performed in order to compare the results of reoperated patients with the results of patients operated on only once. The\\u000a patients completed a standardized questionnaire in 1997 which included questions about reoperations, back and leg pain, functional\\u000a status and disability

A. Vik; J. A. Zwart; G. Hulleberg; Ø. P. Nygaard

2001-01-01

85

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

PubMed Central

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

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

2015-01-01

86

Pure traumatic upper cervical disc herniation causing spinal cord injury: a case report and review of literature  

PubMed Central

Abstract: One third of all spinal injuries involve cervical vertebrae, and the impact of injury to the cervical spinal cord is profound and requires systemic treatment. The role and timing of surgical decompression after an acute spinal cord injury (SCI) remains one of the most controversial topics pertaining to spinal surgery. Lack of controlled, prospective, multicenter clinical studies has contributed to confusion in optimal treatment methods for patients with injuries of the cervical spinal cord. Clinically, the question of whether surgical decompression improves motor recovery following SCI remains surrounded by controversy. Case: Two cases with a 32-year-old man who developed right -sided Brown-Séquard Syndrome Following a motor to car accident with the large right paramedian C3–C4 disc herniation, and ipsilateral spinal cord compression and a 30-year-old man with the syndrome of acute central cervical spinal cord injury with motor impairment involving only upper extremities due to central C2–C3 disc herniation following a pedestrian accident are reported. Discectomy and anterior cervical fusion with the polyetheretherketone (PEEK) cage were performed. A complete motor deficit recovery and a marked sensitive deficit improvement were obtained. The need for and timing of surgical decompression in post traumatic spinal cord injury is controversial. Surgery may expedite neurological recovery in some patients and may provide additional neurological recovery when clinical improvement has plateaued or worsened. In our patient a complete motor deficit recovery was observed. Keywords: Cervical, Disc herniation, Spinal cord injury

Sharifi, Guive; Mosavi, Seyed Ali; Shafieezad, Misagh; Asgari Nosari, Massoud

2012-01-01

87

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

PubMed Central

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

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

2015-01-01

88

Subgaleal hemorrhage with dural tear and parietal-lobe herniation in association with a vacuum extraction.  

PubMed

Use of the vacuum for operative vaginal deliveries has become more favorable with fewer obstetricians and family practitioners trained in the use of forceps. When compared with forcep-assisted deliveries, the vacuum has been associated with a higher incidence of subgaleal hemorrhage (SGH), cephalhematomas, skull and clavicular fractures, Erb's Palsy, intracranial hemorrhage and need for ICN admission. We report the case of an infant who developed a large SGH with midline dural tear and herniation of the medial aspect of the parietal lobes bilaterally in association with a vacuum extraction (VE) delivery. Counseling of families prior to instrumented delivery as to the potential complications, adherence to recommendations for abandoning operative vaginal delivery in favor of a cesarean section and close observation of those infants delivered by VE is warranted. PMID:18034165

Kicklighter, S D; Wolfe, D; Perciaccante, J V

2007-12-01

89

A PHASED REHABILITATION PROTOCOL FOR ATHLETES WITH LUMBAR INTERVERTEBRAL DISC HERNIATION  

PubMed Central

Conservative non-surgical management of a herniated lumbar intervertebral disc (HLD) in athletes is a complex task due to the dramatic forces imparted on the spine during sport participation. The demands placed upon the athlete during rehabilitation and return to sport are unique not only from a sport specific perspective, but also regarding return to the sport strength and conditioning programs utilized for sport preparation. Many prescriptions fail to address postural and motor control faults specific to athletic development, which may prevent full return to sport after suffering a HLD or predispose the athlete to future exacerbations of a HLD. Strength exercises involving squatting, deadlifting, and Olympic power lifts are large components of the typical athlete's conditioning program, therefore some progressions are provided to address potential underlying problems in the athlete's technique that may have contributed to their HLD in the first place. The purpose of this clinical commentary is to propose a framework for rehabilitation that is built around the phases of healing of the disc. Phase I: Non-Rotational/Non-Flexion Phase (Acute Inflammatory Phase), Phase II: Counter rotation/Flexion Phase (Repair Phase), Phase III: Rotational Phase/Power development (Remodeling Phase), and Phase IV: Full return to sport. This clinical commentary provides a theoretical basis for these phases based on available literature as well as reviewing many popular current practice trends in the management of an HLD. The authors recognize the limits of any general exercise rehabilitation recommendation with regard to return to sport, as well as any general strength and conditioning program. It is vital that an individual assessment and prescription is made for every athlete which reviews and addresses movement in all planes of motion under all necessary extrinsic and intrinsic demands to that athlete. Level of Evidence: 5 PMID:24175134

VanGelder, Leonard H.; Vaughn, Daniel W.

2013-01-01

90

Clinical and Magnetic Resonance Imaging Factors Which May Predict the Need for Surgery in Lumbar Disc Herniation  

PubMed Central

Study Design Case-control. Purpose Evaluate clinical and imaging factors which may predict the risk of failure of medical therapy in patients with lumbar disc herniation (LDH). Overview of Literature LDH is a common cause of low back pain and radicular leg pain, with a generally favorable natural course. At present, however, it is not possible to identify patients who may be candidates for surgery in an early stage of their disease by means of clinical signs or diagnostic imaging criteria. Methods We designed a study investigating patients with untreated low back pain to assess the predictive value of demographic, clinical or imaging findings in identifying patients who finally would meet the classic current criteria for surgery. Results Among 134 patients, 80.6% were successfully treated with conservative therapy and 19.4% finally underwent surgery. Sex, occupation, involved root level, presence of Modic changes, osteophytes or annular tears were not significantly different between the 2 groups, while cerebrospinal fluid block, Pfirrmann's grade, location of herniation with regard to the midline, and type of herniation were significantly different. Anteroposterior fragment size was significantly higher and intervertebral foramen height and thecal sac diameters were significantly lower in the surgical group. Conclusions Although it is strongly recommended to practice conservative management at first for patients with LDH symptoms, the results of this study shows that higher Pfirrmann's grade, more laterally located discs, extrusion and protrusion herniation types, and larger fragments could predict the risk of conservative treatment failure. This way, unnecessarily prolonged conservative management (beyond 4-8 weeks) may be precluded. PMID:25187861

Motiei-Langroudi, Rouzbeh; Sadeghian, Homa

2014-01-01

91

Correlative analyses of isolated upper lumbar disc herniation and adjacent wedge-shaped vertebrae  

PubMed Central

Background: Upper lumbar disc herniation (ULDH) is easy to be misdiagnosed due to its special anatomical and atypical clinical features. Few studies have identified the relationship between ULDH and adjacent wedge-shaped vertebrae (WSV). Hypothesis: WSV may have some indicative relations withULDH. Patients and methods: Between January 2003 and October 2013, 47 patients (27 males and 20 females; mean age, 41.2 years) with single-level ULDH (as study group) and 47 sex- and age-matched healthy volunteers (as control group) were studied by radiograph. The two groups were compared with respect to age, sexual proportion, body mass index (BMI), kyphotic angle, and the proportion of WSV. Also, correlative analyses were conducted in the study group to investigate the relation between the kyphotic angle of target vertebrae and other factors including age, BMI, Cobb angle, JOA score and bone mineral density (BMD). Results: The average kyphotic angle in the study group was 11° (4°-22°), while the average kyphotic angle in the control group was 2° (0°-7°). Obviously, the mean kyphotic angle in the study group was statistically larger than that in the control group (t=13.797, P<0.001). The proportion of WSV in the study group was significantly larger than that in the control group (x2=36.380, P<0.0001). The correlations between kyphotic angles and other items (i.e., age, BMI, BMD, Cobb angle and JOA score) in the study group and the control group were low or uncorrelated. Conclusions: WSV are indicatively associated with adjacent ULDH. Thus, ULDH should be alerted when WSV are first found in radiograph and accompanied by clinical symptoms. PMID:25785106

Xu, Jia-Xin; Yang, Si-Dong; Wang, Bao-Lin; Yang, Da-Long; Ding, Wen-Yuan; Shen, Yong

2015-01-01

92

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

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

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

2014-01-01

93

Acute spontaneous cervical disc herniation causing rapidly progressive myelopathy in a patient with comorbid ossified posterior longitudinal ligament: Case report and literature review  

PubMed Central

Background: Ossification of the posterior longitudinal ligament (OPLL) and cervical disc herniation are commonly encountered neurosurgical conditions. Here we present an unusual case of nontraumatic rapidly progressive myelopathy due to cervical disc herniation with comorbid OPLL and conduct a literature review focusing on the frequency and management of disc herniations with OPLL. Case Description: A 52-year-old healthy female presented with a 72-h history of rapid progression of dense quadriparesis with sensory deficits, with a precedent 4-week history of nontraumatic midline neck pain. Clinical examination revealed profound motor deficits below the C5 myotome. Spinal neuroimaging revealed OPLL (computed tomography [CT]) and a cervical disc herniation spanning from C4/5 to C5/6 with significant retrovertebral disease (magnetic resonance imaging [MRI]). Operative management involved an anterior cervical corpectomy and instrumented fusion, with removal of both the sequestered disc material and the locally compressive OPLL. The patient recovered full motor function and independent ambulation with no residual signs or symptoms of myelopathy at the time of discharge. Conclusion: This unique case of a spontaneous cervical disc herniation in the context of OPLL causing rapidly progressive myelopathy illustrates the complementarity of CT and MRI in diagnosing the underlying cause of a rapidly progressive neurologic deficit in the absence of antecedent trauma. Though the optimal surgical management of such pathology remains uncertain; in this case, the anterior approach was motivated by the significant retrovertebral ventrally compressive sequestrum, and provided for excellent neurologic outcome. This article also reviews the occurrence/management of such acute cervical discs with OPLL. PMID:25289163

Westwick, Harrison J.; Goldstein, Christina L.; Shamji, Mohammed F.

2014-01-01

94

Lumbar disc herniation associated with separation of the posterior ring apophysis: analysis of five surgical cases and review of the literature  

Microsoft Academic Search

Summary¶Background. Separation of the posterior ring apophysis of an adjacent vertebral body can sometimes accompany lumbar intervertebral disc herniation. The condition can be both difficult to detect in conventional radiographs and is somewhat controversial to treat. Although there is general agreement on the frequent need for surgery, there is no consensus on the choice of operation. One procedure, posterior lumbar

T. Asazuma; M. Nobuta; M. Sato; M. Yamagishi; K. Fujikawa

2003-01-01

95

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

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

Karimi Khouzani, Reza

2015-01-01

96

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

PubMed Central

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

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

2012-01-01

97

The Surgical Treatment of Single Level Multi-Focal Subarticular and Paracentral and/or Far-Lateral Lumbar Disc Herniations: The Single Incision Full Endoscopic Approach  

PubMed Central

Background Surgery for same level multi-focal extruded lumbar disc herniations is technically challenging and the optimal method controversial. The subarticular disc herniation may pose the most challenging subtype requiring partial or complete facetectomy with or without fusion. The far-lateral disc herniation, often treated using a Wiltse approach, can also be difficult to access especially in the obese patient. When both the subarticular and far-lateral subtypes are simultaneously present at the same level with or without a paracentral disc herniation, a total facetectomy and interbody fusion (TLIF) or a total disc replacement (TDR) may be necessary. Endoscopic surgical techniques may reduce the need for these more invasive methods. Methods Fifteen patients (6 male and 9 female) who had same level multi-focal (subarticular as well as far-lateral and/or paracentral) extruded disc herniations underwent single incision unilateral endoscopic disc excision by the same surgeon at a single institution. Patients were prospectively followed for an average of 15.3 months (range 14-18 months) and outcomes were evaluated radiographically and clinically (Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). Results The mean operative time was 52 minutes with minimal blood loss in all cases. Fourteen of the 15 patients were discharged to home on the day of their surgery. The mean ODI and leg VAS scores improved from 22.9 ± 3.2 to 12.9 ± 2.7 (p < 0.005), and from 8.6 ± 1.6 to 2.1 + 0.4 (p < 0.005), respectively. Conclusions After an average of 15.3 months of follow-up, the clinical and radiographic results of full endoscopic surgical treatment of single level multi-focal (subarticular as well as far-lateral and/or paracentral) disc herniations are excellent. This study is a case series with mid-term follow-up (Level IV). Clinical Relevance Foraminal and extra-foraminal full endoscopic decompression appears to offer a safe minimally invasive solution to a complex pathologic problem. PMID:25694941

Scott, David L.; Han, Xiao; Yacob, Alem

2014-01-01

98

A finite element analysis of the influence of surgical herniation on the viscoelastic properties of the intervertebral disc.  

PubMed

The purpose of this paper was to study the influence of surgical herniation on the viscoelastic properties of the intervertebral disc. The work was broken down into two phases: experimentation and analysis. In the first step of experimentation, five specimens were excised from the L1-L2 level of young adult rhesus monkeys. The prepared specimen consisted of the intervertebral joint and the two adjacent vertebral centrums without either the posterior elements or associated soft tissue. The specimens were subjected to a constant compressive load for eight hours followed by a sixteen hour relaxation time. During all the load cycles, displacement of the specimens was measured with an LVDT. After the first compressive test, the specimens were herniated and then the compressive test repeated. In the second phase of the work, a viscoelastic axisymmetric finite element model was used to quantify the experimental data. A three parameter Kelvin solid was employed in the finite element model. The results of this paper will be used to construct a dynamic model for the vertebral column. PMID:6643516

Furlong, D R; Palazotto, A N

1983-01-01

99

Clinical factors of importance for outcome after lumbar disc herniation surgery: long-term follow-up  

PubMed Central

Factors as age, sex, smoking, duration of leg pain, working status, type/level of disc herniation and psychosocial factors have been demonstrated to be of importance for short-term results after lumbar discectomy. There are few studies with long-term follow-up. In this prospective study of lumbar disc herniation patients undergoing surgery, the result was evaluated at 2 and 5–10 (mean 7.3) years after surgery. Predictive factors for satisfaction with treatment and objective outcome were investigated. Out of the included 171 patients undergoing lumbar discectomy, 154 (90%) patients completed the 2-year follow-up and 140 (81%) completed the long-term follow-up. Baseline data and questionnaires about leg- and back pain intensity (VAS), duration of leg pain, disability (Oswestry Disability Index), depression (Zung Depression Scale), sick leave and employment status were obtained preoperatively, at 2-year- and long-term follow-up. Primary outcome included patient satisfaction with treatment (at both time points) and assessment of an independent observer at the 2-year follow-up. Secondary outcomes at 2-year follow-up were improvement of leg and back pain, working capacity and the need for analgesics or sleeping pills. In about 70% of the patients excellent or good overall result was reported at both follow-ups, with subjective outcome measurements. The objective evaluation after 2 years was in agreement with this result. Time on sick leave was found to be a clinically important predictor of the primary outcomes, with a potential of changing the probability of a satisfactory outcome (both objective and subjective) from around 50% (sick leave >3 months) to 80% (sick leave <2 months). Time on sick leave was also an important predictor for several of the secondary outcomes; e.g. working capacity and the need for analgesics. PMID:20512513

Lind, B.; Zoëga, B.; Halldin, K.; Gellerstedt, M.; Brisby, H.; Rutberg, L.

2010-01-01

100

Comparison of the Efficacy of Caudal, Interlaminar, and Transforaminal Epidural Injections in Managing Lumbar Disc Herniation: Is One Method Superior to the Other?  

PubMed Central

Background Epidural injections are performed utilizing 3 approaches in the lumbar spine: caudal, interlaminar, and transforaminal. The literature on the efficacy of epidural injections has been sporadic. There are few high-quality randomized trials performed under fluoroscopy in managing disc herniation that have a long-term follow-up and appropriate outcome parameters. There is also a lack of literature comparing the efficacy of these 3 approaches. Methods This manuscript analyzes data from 3 randomized controlled trials that assessed a total of 360 patients with lumbar disc herniation. There were 120 patients per trial either receiving local anesthetic alone (60 patients) or local anesthetic with steroids (60 patients). Results Analysis showed similar efficacy for caudal, interlaminar, and transforaminal approaches in managing chronic pain and disability from disc herniation. The analysis of caudal epidural injections showed the potential superiority of steroids compared with local anesthetic alone a 2-year follow-up, based on the average relief per procedure. In the interlaminar group, results were somewhat superior for pain relief in the steroid group at 6 months and functional status at 12 months. Interlaminar epidurals provided improvement in a significantly higher proportion of patients. The proportion of patients nonresponsive to initial injections was also lower in the group for local anesthetic with steroid in the interlaminar trial. Conclusions The results of this assessment show significant improvement in patients suffering from chronic lumbar disc herniation with 3 lumbar epidural approaches with local anesthetic alone, or using steroids with long-term follow-up of up to 2 years, in a contemporary interventional pain management setting. PMID:25589942

Singh, Vijay; Pampati, Vidyasagar; Falco, Frank JE; Hirsch, Joshua A.

2015-01-01

101

A Minimally Invasive Treatment for Lumbar Disc Herniation: DiscoGel® Chemonucleolysis in Patients Unresponsive to Chemonucleolysis with Oxygen-Ozone  

PubMed Central

Summary A multitude of therapies is available to treat disc herniation, ranging from conservative methods (medication and physical therapy) to minimally invasive (percutaneous) treatments and surgery. O2-O3 chemonucleolysis (O2-O3 therapy) is one of the minimally invasive treatments with the best cost/benefit ratio and lowest complication rate. Another substance recently made available exploiting the chemical properties of pure ethanol is DiscoGel®, a radiopaque gelified ethanol more viscous than absolute alcohol8,9. The present study aimed to assess the therapeutic outcome of DiscoGel® chemonucleolysis in patients with lumbar disc herniation unresponsive to O2-O3 therapy. Thirty-two patients aged between 20 and 79 years were treated by DiscoGel® chemonucleolysis between December 2008 and January 2010. The treatment was successful (improvement in pain) in 24 out of 32 patients. DiscoGel® is safe and easy to handle and there were no complications related to product diffusivity outside the treatment site. The therapeutic success rate of DiscoGel® chemonucleolysis in patients unresponsive to O2-O3 therapy was satisfactory. Among other methods used to treat lumbar disc herniation, DiscoGel® chemonucleolysis can be deemed an intermediate procedure bridging conservative medical treatments and surgery. PMID:22440607

Stagni, S.; de Santis, F.; Cirillo, L.; Dall’Olio, M.; Princiotta, C.; Simonetti, L.; Stafa, A.; Leonardi, M.

2012-01-01

102

Comparative analysis of the influence of Fructus Ligustri Lucidi on a rat lumbar disc herniation model.  

PubMed

Lumbar disc herniation (LDH) is a term used for a group of conditions, including back pain, femoral nerve pain and sciatica. Currently available treatments and surgical options are insufficient for patients with LDH. Fructus Ligustri Lucidi (FLL) is a herb that is used for treating age?associated diseases. The results of the present study suggested that FLL may be used for treatment of patients with LDH. In the present study, matrix metalloproteinase?1, ?3, ?8 and ?9 (MMP?1, ?3, ?8 and ?9) protein and mRNA expression downregulation was observed in patients with LDH according to western blotting and reverse transcription?quantitative polymerase chain reaction. By contrast, upregulation of interleukin?2 (IL?2), IL?6, IL?8 and tumor necrosis factor?? (TNF??) expression was observed in patients with LDH, according to an enzyme?linked immunosorbent assay. Mechanical allodynia was observed in rats with LDH not treated with FLL; however, not in FLL?treated rats. IL?2, IL?6, IL?8 and TNF?? expression levels in the serum from untreated rats were significantly higher than that of the FLL?treated rat models. Protein expression levels of MMPs in FLL?treated rats were lower than those in untreated rats. However, the mechanisms underlying the association between FLL and protein expression levels require further investigation. PMID:25816023

Han, Ya-Xin; Liang, Dong; Han, Xiao-Rui; Liang, De-Yong

2015-07-01

103

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

NASA Technical Reports Server (NTRS)

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.

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

2015-01-01

104

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

Microsoft Academic Search

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

Tomasz Sipko; Marzena Chantsoulis; Micha? Kuczy?ski

2010-01-01

105

The Combined Use of a Posterior Dynamic Transpedicular Stabilization System and a Prosthetic Disc Nucleus Device in Treating Lumbar Degenerative Disc Disease With Disc Herniations  

PubMed Central

Background Prosthetic replacement of spinal discs is emerging as a treatment option for degenerative disc disease. Posterior dynamic transpedicular stabilization (PDTS) and prosthetic disc nucleus (PDN) devices have been used sporadically in spinal surgery. Methods This was a prospective study of 13 patients averaging 40.9 years of age with degenerative disc disease who underwent posterior placement of a PDN with a PDTS. The Oswestry low-back pain disability questionnaire and visual analog scale (VAS) for pain were used to assess patient outcomes at the 3rd, 6th, and 12th postoperative months. Lumbar range of motion was evaluated using a bubble inclinometer preoperatively and at 12 months postoperatively. Radiological parameters including lumbar lordosis angle (LL), segmental lordosis angle (?), disc height at the operated level (DHo), and disc height of the adjacent level (DHu) were evaluated. A typical midline posterior approach for complete discectomy was followed by the simultaneous placement of the PDN with PDTS. Results Both the Oswestry and VAS scores showed significant improvement postoperatively (P < .05). There were no significant differences in LL, ?, DHo, and DHu parameters. We observed complications in 3 patients including 2 patients who had the PDN device embedded into the adjacent corpus; 1 had massive endplate degeneration, and the other experienced interbody space infection. In 1 patient, the PDN device migrated to one side in the vertebral space. Conclusion The use of a PDN in combination with posterior dynamic instrumentation can help to restore the physiologic motion of the anterior and posterior column and could help to establish posterior dynamic instrumentation as an important treatment of degenerative disc disease. Theoretically this concept is superior, but practically we need more advanced technology to replace disc material. Because this study examined the combination of the PDN and stabilization instrumention, the results cannot be compared with those reported in the literature for either PDN alone or dynamic screws alone. Level of Evidence Prospective cohort study with good follow-up (level 1b).

Aydin, Ahmet Levent; Oktenoglu, Tunc; Cosar, Murat; Ataker, Yaprak; Kaner, Tuncay; Ozer, Ali Fahir

2008-01-01

106

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

PubMed Central

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

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

107

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

PubMed

[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

Choi, Jioun; Lee, Sangyong; Hwangbo, Gak

2015-02-01

108

Comparison Of Percutaneous Laser Discectomy With Other Modalities For The Treatment Of Herniated Lumbar Discs And Cadaveric Studies Of Percutaneous Laser Discectomy  

NASA Astrophysics Data System (ADS)

Current modalities for treating a herniated lumbar disc include standard open discectomy, microsurgical discectomy, chemonucleoysis and percutaneous discectomy. The Food and Drug Administration has not yet approved percutaneous laser discectomy for clinical investigation. The investigators believe that percutaneous laser discectomy combines the efficacy of both chemonucleoysis and percutaneous discectomy with the safety of both open standard discectomy and microsurgical discectomy. The investigators removed two lumbar discs from a cadaveric spine and weighed each of them. The two lumbar discs weighed in the range of 13.654 grams and 15.713 grams, respectively. The investigators initiated several series of 10 firing cycles from a surgical carbon dioxide laser system. In each firing cycle the surgical carbon dioxide laser system delivered a beam of light energy having an output power of 18.0 watts at pulse duration of 0.045 second at the rate of 15 pulses per second for a period of 6 seconds and vaporized approximately 325 milligrams of disc material. Based on the findings of other investigators reported in the literature relating to percutaneous discectomy the investigators postulated that 10 to 20 firing cycles are required to vaporize 30 to 40% (2.4 to 6.4 grams) of the disc material. The investigators initiated two series of 10 firing cycles in order to perform laser discectomy in a third lumbar disc of the cadaveric spine in situ. The investigators harvested and then bisected the laser-treated third lumbar disc for gross review. Their gross findings indicated a high probability of success For percutaneous laser discectomy.

Johansen, W. E.; Smith, Chadwick F.; Vangsness, Thomas; McEleney, Emmett T.; Yamaguchi, Ken; Bales, Peter

1987-03-01

109

Subgaleal hemorrhage with dural tear and parietal-lobe herniation in association with a vacuum extraction  

Microsoft Academic Search

Use of the vacuum for operative vaginal deliveries has become more favorable with fewer obstetricians and family practitioners trained in the use of forceps. When compared with forcep-assisted deliveries, the vacuum has been associated with a higher incidence of subgaleal hemorrhage (SGH), cephalhematomas, skull and clavicular fractures, Erb's Palsy, intracranial hemorrhage and need for ICN admission. We report the case

S D Kicklighter; D Wolfe; J V Perciaccante

2007-01-01

110

Herniated Cervical Disc  

MedlinePLUS

... collar, anti-inflammatory medications to reduce the swelling, analgesic drugs to control the pain, physical therapy, exercise ... management Medications used to control pain are called analgesics. Most pain can be treated with nonprescription medications ...

111

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

PubMed Central

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

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

2014-01-01

112

Four-year follow-up results of transforaminal lumbar interbody fusion as revision surgery for recurrent lumbar disc herniation after conventional discectomy.  

PubMed

This study investigated the safety, effectiveness, and clinical and radiological outcomes of transforaminal lumbar interbody fusion (TLIF) for recurrent lumbar disc herniation (rLDH) following previous lumbar spine surgery. Seventy-three consecutive patients treated for rLDH between June 2005 and May 2012 were included in the study. The previous surgical procedures included percutaneous discectomy, discectomy with laminotomy, discectomy with unilateral laminectomy, and discectomy with bilateral laminectomy. The level of rLDH was L4-L5 in 51 patients, L5-S1 in 19 patients, and L3-L4 in three patients. All patients underwent reoperation using the TLIF technique. Outcomes were evaluated using the Oswestry disability index (ODI), visual analogue scale (VAS) scores for low back pain and leg pain, and the Japanese Orthopaedic Association (JOA) score, based on the results of physical examinations and questionnaires. The range of motion and disc height index of the operative segment were compared between preoperative and postoperative radiographs. The mean follow-up period was 4.1 years. The VAS scores for low back pain and leg pain, ODI, and JOA score improved significantly between the preoperative and final follow-up evaluations. The mean recovery rate of the JOA score was 89.0%. The disc space height and stability at the fused level were significantly improved after surgery. The fusion rate at the final follow-up was 93.2%. There were no major complications. These results indicate that TLIF can be considered an effective, reliable, and safe alternative procedure for the treatment of rLDH. PMID:25443080

Li, Zhonghai; Tang, Jiaguang; Hou, Shuxun; Ren, Dongfeng; Li, Li; Lu, Xiang; Hou, Tiesheng

2015-02-01

113

Modification of rat model of sciatica induced by lumber disc herniation and the anti-inflammatory effect of osthole given by epidural catheterization.  

PubMed

One of the most treatable causes of lower back pain and associated sciatica is lumbar disc herniation (LDH), which is characterized by rupture of the hard outer wall (annulus fibrosis) in a lumbar intervertebral disc. In the current study, we aimed to: (1) develop and characterize a rat model of sciatica induced by LDH, while introducing a novel method of epidural catheterization; (2) use this model to evaluate the effect of osthole on pain due to LDH, and (3) gain insight into the mechanisms through which osthole affects sciatica induced by LDH. The results indicate that our newly developed rat model maintained mechanical allodynia for 28 days without reduction. Moreover, cyclooxygenase-2 (COX-2) and nitric oxide synthase (NOS) were overexpressed in the associated inflammatory response, which is consistent with clinical manifestations of the disease. We then used this model to study the effect and mechanisms through which osthole affected pain due to LDH. Our study suggests that osthole is capable of reversing hyperalgesia due to LDH, potentially through modulation of activity of COX-2 and NOS, two important proteins for the exacerbation of pain due to LDH. Finally, a molecular modeling simulation showed that osthole has unique binding capabilities to both NOS and COX-2. As the model-induced mechanical hyperalgesia response was consistent, and the position of the catheter tip and the extension/spreading of the drug in the epidural space were reliable, this study developed an improved model to study remedies for sciatic pain. Moreover, our studies demonstrate that osthole may be a feasible treatment for the reduction of pain due to hyperalgesia. PMID:23018204

Wei, Ming; Mo, Sui-Lin; Nabar, Neel R; Chen, Yuling; Zhang, Jin-Jun; He, Qiu-Lan; Zou, Xue-Nong; Liu, Xian-Guo; Sun, Lai-Bao; Zhou, Shu-Feng

2012-01-01

114

Transforaminal epidural steroid injections prevent the need for surgery in patients with sciatica secondary to lumbar disc herniation: a retrospective case series  

PubMed Central

Background The median orthopedic surgery wait time in Canada is 33.7 weeks, thus alternative treatments for pathologies such as lumbar disc herniations (LDH) are needed. We sought to determine whether transforaminal epidural steroid injections (TFESIs) alleviate or merely delay the need for surgery. Methods We retrospectively reviewed the charts of patients with LDH who received TFESIs between September 2006 and July 2008. Patient demographics, level and side of pathology, workers’ compensation status, levels injected, treatment outcome and time from referral to treatment were evaluated. The primary outcome measure was the need for versus the avoidance of surgery. Results We included 91 patients in our analysis. Time from family physician referral to injection was 123 (standard deviation [SD] 88) days; no significant differences in wait times were found between TFESI patients and those requiring surgery. In all, 51 patients (22 women, 29 men) with a mean age of 45.8 (SD 10.2) years avoided surgery following TFESI, whereas 40 patients (16 women, 24 mean) with a mean age of 43.1 (SD 12.0) years proceeded to surgery within 189 (SD 125) days postinjection. In all, 15 patients received multiple injections, and of these, 9 did not require surgical intervention. Age, sex and level/side of pathology did not influence the treatment outcome. Workers’ compensation status influenced outcome significantly; these patients demonstrated less benefit from TFESI. Conclusion Transforaminal epidural steroid injections are an important treatment tool, preventing the need for surgery in 56% of patients with LDH. PMID:23351495

Manson, Neil A.; McKeon, Melissa D.; Abraham, Edward P.

2013-01-01

115

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

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

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

2009-01-01

116

Foraminoplastic transfacet epidural endoscopic approach for removal of intraforaminal disc herniation at the L5-S1 level  

PubMed Central

Transforaminal endoscopic disc removal in the L5-S1 motion segment of the lumbar spine creates a technical challenge due to anatomical reasons and individual variability. The majority of surgeons prefer a posterior classical or minimally invasive approach. There is only one foraminoplastic modification of the technique in the literature so far. In this paper we present a new technique with a foraminoplastic transfacet approach that may be suitable in older patients with advanced degenerative disease of the spine. PMID:24729817

Kaczmarczyk, Jacek; Nowakowski, Andrzej; Sulewski, Adam

2014-01-01

117

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

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.

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

2014-01-01

118

Psychometric properties of the Polish language version of the Chronic Pain Coping Inventory-42 for patients treated surgically due to herniated lumbar discs and spondylotic changes  

PubMed Central

Background The development of a pain-management program tailored to the specific needs of patients with chronic low back pain (CLBP) requires the proper assessment of psychosocial factors affecting each individual. The Chronic Pain Coping Inventory-42 (CPCI-42) refers to coping strategies, which are commonly defined as the cognitive and behavioral techniques an individual may resort to in stressful or demanding situations. Evidence from a number of sources suggests that differences in pain coping strategies may significantly affect how an individual deals with chronic pain. We aimed to adapt the CPCI-42 to Polish cultural conditions (PL-CPCI-42) and then verify its psychometric properties based on a group of patients treated surgically due to herniated lumbar discs and coexisting spondylotic changes. Material/Methods The average age of the study participants (n=90) was 43.47 years (SD 10.21). The average duration of chronic low back pain (CLBP) was 49.37 months (SD 64.71). Lumbosacral spine X-rays and magnetic resonance imaging scans were performed and all patients completed the PL-CPCI-42 and the Polish versions of the Numeric Pain Rating Scale (NPRS-PL) twice. Internal consistency of the PL-CPCI-42, floor and ceiling effects, test-retest reliability, and criterion validity were analyzed. Results Resting, guarding, and coping self-statements were frequently used as coping strategies both in the test and in the retest, in contrast to relaxation and exercise/stretch. The NPRS-PL result was 5.70 cm in the test and 5.66 in the retest. Cronbach’s alpha values were recorded for the asking for assistance, coping self-statements, and seeking social support domains (0.83, 0.80, 0.83, respectively). Test-retest reliability of the PL-CPCI-42 varied from 0.53 (relaxation domain) to 0.84 (asking for assistance and coping self-statements domains). Conclusions The present study provides evidence of the validity of the PL-CPCI-42 and supports its usefulness in assessing chronic pain coping strategies, which are especially important to pain adjustment and in the creation of multidisciplinary pain management programs for patients with severe CLBP. PMID:24824781

Misterska, Ewa; Jankowski, Roman; G?owacki, Maciej

2014-01-01

119

Childhood intervertebral disc calcification  

Microsoft Academic Search

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

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

1993-01-01

120

Subjective health complaints in patients with lumbar radicular pain and disc herniation are associated with a sex - OPRM1 A118G polymorphism interaction: a prospective 1-year observational study  

PubMed Central

Background Earlier observations show that development of persistent pain may be associated with the genetic variability in the gene encoding for the ?-opioid receptor 1, the OPRM1 A118G (rs1799971). The aim of this study was to investigate the association between OPRM1 genotype and subjective health complaints in patients with radicular pain and disc herniation. Methods A prospective, 1-year observational study was conducted at a hospital back clinic, including 118 Caucasian patients with lumbar radicular pain and MRI confirmed disc herniation. Single nucleotide polymorphism genotyping regarding the OPRM1 A118G was performed. The data of individuals with AA versus AG or GG were analysed separately by linear mixed models. The Subjective Health Complaints Inventory (0-81) including 27 common complaints experienced the previous month on a scale from not at all (0) to severe (3) was used as outcome. Pain, prior duration of leg pain, age, smoking status, and lumbar disc surgery were considered as covariates. Results In total 23 of 118 patients were carriers of the OPRM1 G-allele. All patients except female carriers of the G-allele reported a decrease in pain from baseline to 1 year. Female carriers of the G-allele reported significantly higher subjective health complaints score during the study time span than male carriers of the G-allele when controlling for pain and pain duration. Conclusion The present data indicate that, when controlling for pain intensity and duration, subjective health complaints are associated with a sex - OPRM1 A118G polymorphism interaction in patients with radicular pain. PMID:24884878

2014-01-01

121

A Combinatorial Relative Mass Value Evaluation of Endogenous Bioactive Proteins in Three-Dimensional Cultured Nucleus Pulposus Cells of Herniated Intervertebral Discs: Identification of Potential Target Proteins for Gene Therapeutic Approaches  

PubMed Central

Painful degenerative disc diseases have been targeted by different biological treatment approaches. Nucleus pulposus (NP) cells play a central role in intervertebral disc (IVD) maintenance by orchestrating catabolic, anabolic and inflammatory factors that affect the extracellular matrix. IVD degeneration is associated with imbalances of these factors, resulting in a catabolic inflammatory metabolism. Therefore, accurate knowledge about their quantity and quality with regard to matrix synthesis is vital for a rational gene therapeutic approach. NP cells were isolated from 63 patients operated due to lumbar disc herniation (mean age 56 / range 29 - 84 years). Then, three-dimensional culture with low-glucose was completed in a collagen type I scaffold for four weeks. Subsequently cell proliferation evaluation was performed using 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide and intracellular concentration of 28 endogenously expressed anabolic, catabolic, inflammatory factors and relevant matrix proteins was determined by enzyme-linked immunosorbent assay. Specimen-related grades of degeneration were confirmed by preoperative magnetic resonance imaging. Independent from gender, age and grade of degeneration proliferation rates remained similar in all groups of NP cells. Progressive grades of degeneration, however, showed a significant influence on accumulation of selective groups of factors such as disintegrin and metalloproteinase with thrombospondin motifs 4 and 5, matrix metalloproteinase 3, metalloproteinase inhibitor 1 and 2, interleukin-1? and interleukin-1 receptor. Along with these changes, the key NP matrix proteins aggrecan and collagen II decreased significantly. The concentration of anabolic factors bone morphogenetic proteins 2, 4, 6 and 7, insulin-like growth factor 1, transforming growth factor beta 1 and 3, however, remained below the minimal detectable quantities. These findings indicate that progressive degenerative changes in NP may be problematic with regard to biologic treatment strategies. Hence, gene therapeutic interventions regulating relevant bioactive factors identified in this work might contribute to the development of regenerative treatment approaches for degenerative disc diseases. PMID:24278441

Mern, Demissew S.; Fontana, Johann; Beierfuß, Anja; Thomé, Claudius; Hegewald, Aldemar A.

2013-01-01

122

Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum  

PubMed Central

Summary Graphene-based electrodes are very promising for molecular electronics and spintronics. Here we report a systematic characterization of the electroburning (EB) process, leading to the formation of nanometer-spaced gaps, on different types of few-layer graphene (namely mechanically exfoliated graphene on SiO2, graphene epitaxially grown on the C-face of SiC and turbostratic graphene discs deposited on SiO2) under air and vacuum conditions. The EB process is found to depend on both the graphene type and on the ambient conditions. For the mechanically exfoliated graphene, performing EB under vacuum leads to a higher yield of nanometer-gap formation than working in air. Conversely, for graphene on SiC the EB process is not successful under vacuum. Finally, the EB is possible with turbostratic graphene discs only after the creation of a constriction in the sample using lithographic patterning.

Richter, Nils; Convertino, Domenica; Coletti, Camilla; Balestro, Franck; Wernsdorfer, Wolfgang; Kläui, Mathias; Affronte, Marco

2015-01-01

123

Percutaneous cervical disc decompression  

Microsoft Academic Search

Background  Cervical disc nucleoplasty is a significant and clinically demonstrated innovation in percutaneous disc decompression in case\\u000a of non-herniated disc protrusions or prolpase. It allows a percutaneous decompression via a 19-gauge needle under utilization\\u000a of the Coblation® technique and under C-arm control. Until now the patients suffering of a cervicobrachialgia in cause of a disc prolapse had\\u000a only the therapeutical solution

Klaus Birnbaum

2009-01-01

124

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

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.

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

125

Can Prevention of a Reherniation Be Investigated? Establishment of a Herniation Model and Experiments With an Anular Closure Device  

PubMed Central

Study Design. Biomechanical in vitro study. Objective. To establish a reliable in vitro herniation model with human cadaver spines that enables evaluation of anular closure devices. Summary of Background Data. Biomechanically, it is desirable to close anulus defects after disc herniation to preserve as much nucleus as possible. Multiple anular closure options exist to prevent reherniation. A reliable test procedure is needed to evaluate the efficacy and reliability of these implants. Methods. Two groups of human lumbar segments (n = 6 per group) were tested under cyclic loading until herniation occurred or 100,000 load cycles were applied. One group contained moderate/severe degenerated discs. A second group had mild degenerated discs. Intradiscal pressure was measured in the intact state to confirm disc quality. If herniation occurred, the extruded material was reinserted into the disc and the anulus defect was treated with the Barricaid anular closure device (Intrinsic Therapeutics, Inc., Woburn, MA). Disc height and 3-dimensional flexibility of the specimens in the intact, defect, and implanted states were measured under pure moments in each principal motion plane. Afterwards, provocation of reherniation was attempted with additional 100,000 load cycles. Results. Likelihood of herniation was strongly linked to disc degeneration and supported by the magnitude of intradiscal pressure. In moderate/severe degenerated discs, only 1 herniation was created. In mild degenerated discs, herniations were reliably created in all specimens. Using this worst-case model, herniation caused a significant reduction of disc height, which was nearly restored with the implant. In no case was reherniation or implant migration visible after 100,000 load cycles after Barricaid implantation. Conclusion. We established a human herniation model that reliably produced nucleus extrusion during cyclic loading by selecting specimens with low disc degeneration. The Barricaid seems to prevent nucleus from reherniating. The reliability of this method suggests the opportunity to investigate other anulus closure devices and nucleus replacement techniques critically. PMID:23429676

Wilke, Hans-Joachim; Ressel, Lena; Heuer, Frank; Graf, Nicolas; Rath, Stefan

2013-01-01

126

Traumatic extrathoracic lung herniation  

Microsoft Academic Search

Traumatic extrathoracic lung herniation is an exceptional complication of blunt chest trauma. We report the case of a 46-year-old man who was involved in a motorcycle accident and who suffered a left clavicle fracture-dislocation associated with multiple rib fractures and massive herniation of the left upper lobe through an upper anterior chest wall defect. Immediate surgical repair through an atypical

Pierre-Mathieu Bonnet; François Pons; Louis Brinquin; René Jancovici

2002-01-01

127

Traumatic extrathoracic lung herniation.  

PubMed

Traumatic extrathoracic lung herniation is an exceptional complication of blunt chest trauma. We report the case of a 46-year-old man who was involved in a motorcycle accident and who suffered a left clavicle fracture-dislocation associated with multiple rib fractures and massive herniation of the left upper lobe through an upper anterior chest wall defect. Immediate surgical repair through an atypical transcostal vertical thoracotomy resulted in full recovery of pulmonary function at 1 year. PMID:12238872

Lang-Lazdunski, Loïc; Bonnet, Pierre-Mathieu; Pons, François; Brinquin, Louis; Jancovici, René

2002-09-01

128

The cell biology of intervertebral disc aging and degeneration  

Microsoft Academic Search

Intervertebral disc degeneration, which mimics disc aging but occurs at an accelerated rate, is considered to be related to neck or low back pain and disc herniation. Degenerated discs show breakdown of the extracellular matrix and thus fail to bear the daily loadings exerted on the spine. Rather than a passive process of wear and tear, disc degeneration is an

Chang-Qing Zhao; Li-Min Wang; Lei-Sheng Jiang; Li-Yang Dai

2007-01-01

129

Advances in susceptibility genetics of intervertebral degenerative disc disease.  

PubMed

The traditional view that the etiology of lumbar disc herniation is primarily due to age, gender, occupation, smoking and exposure to vehicular vibration dominated much of the last century. Recent research indicates that heredity may be largely responsible for the degeneration as well as herniation of intervertebral discs. Since 1998, genetic influences have been confirmed by the identification of several genes forms associated with disc degeneration. These researches are paving the way for a better understanding of the biologic mechanisms. Now, many researchers unanimously agree that lumbar disc herniation appears to be similar to other complex diseases, whose etiology has both environmental and hereditary influence, each with a part of contribution and relative risk. Then addressing the etiological of lumbar disc herniation, it is important to integrate heredity with the environment factors. For the purpose of this review, we have limited our discussion to several susceptibility genes associated with disc degeneration. PMID:18781226

Zhang, Yin'gang; Sun, Zhengming; Liu, Jiangtao; Guo, Xiong

2008-01-01

130

Herniated nucleus pulposus as a result of emesis in a 20-yr-old man.  

PubMed

The causes of herniated disc in vivo vary, and recent studies stress the role of intradiscal pressure as an important factor. Identifying causes of increased intradiscal pressure is difficult. This case report describes the diagnosis of a herniated nucleus pulposus in a 20-yr-old healthy man, with sudden onset of emesis. The diagnosis was made by a complete history, physical examination, electrodiagnostic studies, and magnetic resonance imaging. This etiology of herniated nucleus pulposus has not been described in the medical literature, and the severity of the symptoms, clinical examination, electrodiagnostic findings, and radiologic findings are discussed. Intradiscal pressures and their role in herniated nucleus pulposus are discussed, with a review of the medical literature on the measurement of intradiscal pressure. The amount of force required to produce a herniated nucleus pulposus is also discussed. PMID:15024336

Pecha, Marc D

2004-04-01

131

Cervical arthroplasty using ProDisc-C case report.  

PubMed

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

Nica, D A; Copaciu, R

2013-03-15

132

Lumbar disc nucleoplasty using coblation technology: clinical outcome  

Microsoft Academic Search

Background and purposeAlthough the standard treatment for lumbar disc herniation is lumbar microdiscectomy, nucleoplasty offers a new technique with encouraging results in well selected cases. Nucleoplasty is a minimally invasive technique that manages intradiscal herniation through energy based removal of part of the nucleus pulposus. The purpose of this study was to assess the safety and clinical outcome of the

Alaa Azzazi; Sherif AlMekawi; Mostafa Zein

2010-01-01

133

Intramuscular Oxygen-Ozone Therapy in the Treatment of Acute Back Pain With Lumbar Disc Herniation A Multicenter, Randomized, Double-Blind, Clinical Trial of Active and Simulated Lumbar Paravertebral Injection  

Microsoft Academic Search

Study Design. Multicenter randomized, double-blind, simulated therapy-controlled trial in a cohort of patients with acute low back pain (LBP) due to lumbar disc herni- ation (LDH). Objective. To assess the benefit of intramuscular-para- vertebral injections of an oxygen-ozone (O2O3) mixture. Summary of Background Data. Recent findings have shown that O2O3 therapy can be used to treat LDH that fails to

Marco Paoloni; Angelo Cacchio; Dario Apuzzo; Salvatore Marotta; Michele Razzano; Marianno Franzini; Valter Santilli

134

Percutaneous disc decompression for the treatment of chronic atypical cervical discogenic pain.  

PubMed

Percutaneous disc decompression with the radiofrequency coblation technique has been described to treat contained, symptomatic lumbar disc herniations. In symptomatic cervical disc herniations it has been used very selectively. We report a 42-year-old female with cervical disc pathology, predominantly at C6/C7, treated with percutaneous disc decompression using coblation technology. Her complaint of cervicogenic cephalgia completely resolved, along with an 85% reduction of neck pain and upper extremity pain 6-months post-operatively. This is the first case report of chronic cervical discogenic pain being treated with this technique. PMID:16868623

Singh, Vijay

2004-01-01

135

Fusion around cervical disc prosthesis: case report  

Microsoft Academic Search

OBJECTIVE AND IMPORTANCE: Cervical arthroplasty is a relatively new method to maintain motion after cervical anterior discectomy. Two cases are presented in which bony fusion occurred around a cervical disc prosthesis. CLINICAL PRESENTATION: A 30-year-old man and a 49-year-old woman underwent a right-sided anterior cervical discectomy because of pain in the right arm resulting from a herniated disc (C5-C6). INTERVENTION:

Ronald H. M. A. Bartels; Roland Donk

2005-01-01

136

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

E-print Network

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 ...

Hastreiter, Dawn (Dawn Marie), 1973-

2002-01-01

137

Paraduodenal herniation: An internal herniation in a virgin abdomen  

PubMed Central

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

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

2014-01-01

138

[Traumatic recurrence of idiopathic spinal cord herniation].  

PubMed

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

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

2013-01-01

139

Lumbar disk herniation with contralateral symptoms.  

PubMed

The aim of the study is to determine if leg pain can be caused by contralateral lumbar disk herniation and if intervention from only the herniation side would suffice in these patients. Five patients who had lumbar disk herniations with predominantly contralateral symptoms were operated from the side of disk herniation without exploring or decompressing the symptomatic side. Patients were evaluated pre- and postoperatively. To our knowledge, this is the first reported series of such patients who were operated only from the herniation side. The possible mechanisms of how contralateral symptoms predominate in these patients are also discussed. In all patients, the shape of disk herniations on imaging studies were quite similar: a broad-based posterior central-paracentral herniated disk with the apex deviated away from the side of the symptoms. The symptoms and signs resolved in the immediate postoperative period. Our data clears that sciatica can be caused by contralateral lumbar disk herniation. When operation is considered, intervention only from the herniation side is sufficient. It is probable that traction rather than direct compression is responsible from the emergence of contralateral symptoms. PMID:16231173

Sucu, Hasan Kamil; Gelal, Fazil

2006-05-01

140

Intervertebral disc replacement for cervical degenerative disease – clinical results and functional outcome at two years in patients implanted with the Bryan ® cervical disc prosthesis  

Microsoft Academic Search

Summary  \\u000a Background. This is a prospective study of patients with degenerative cervical disease who underwent ventral discectomy and disc replacement\\u000a with the Bryan® cervical disc prosthesis. The objective was to investigate clinical outcome at 2 years of patients implanted with the Bryan® disc and to evaluate function of the implant itself.\\u000a \\u000a \\u000a Methods. Fifty-four consecutive patients with cervical disc herniation and\\/or

V. Heidecke; W. Burkert; M. Brucke; N. G. Rainov

2008-01-01

141

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

Microsoft Academic Search

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

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

2010-01-01

142

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2010 CFR

...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

2010-10-01

143

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2012 CFR

...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

2012-10-01

144

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2011 CFR

...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

2011-10-01

145

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2014 CFR

...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

2014-10-01

146

46 CFR 64.61 - Rupture disc.  

Code of Federal Regulations, 2013 CFR

...SECURITY (CONTINUED) MARINE ENGINEERING MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS Pressure Relief Devices and Vacuum Relief Devices for MPTs § 64.61 Rupture disc. If a rupture disc is the only pressure relief device on the tank,...

2013-10-01

147

[The apparent parallelism of L5-S1 as an early radiologic sign of lumbo-sacral disk herniation].  

PubMed

The purpose of ths study was to confirm the authors' impression of parallel margins between the lower vertebral plate of the last lumbar vertebra and the upper plate of the first sacral vertebra in patients suffering from herniation of the last disc. The study involved 3 groups of patients: the first comprised patients with sciatica due to compression of the S1 nerve root, the second group consisted of normal subjects and the third included patients suffering from low back pain without disc pathology. The results show that a parallel appearance between the L5 ad S1 vertebral bodies was apparent for angles of lambda less than or equal to 10 degrees. The authors have found these parallel margins only in patients suffering from disc herniation between L5 and S1. PMID:6453424

Radi, I; Balagué, F

1981-04-18

148

Osteopoikilosis mimicking lumbar disc herniation: a case report  

Microsoft Academic Search

It is important for the chiropractor to be able to determine the nature of the pathology discovered on plain film radiography, and to suggest appropriate follow-up investigations, deemed to be clinically appropriate. This case demonstrates the value of plain-film radiography in diagnosing a rare sclerosing bone dysplasia, which in 10–15% of affected individuals is associated with articular pain and swelling.

Michelle Wessely

2000-01-01

149

Lumbar disc herniation mimicking meralgia paresthetica: case report  

Microsoft Academic Search

BACKGROUNDMeralgia paresthetica, a syndrome of pain and\\/or dysesthesia in the anterolateral thigh, is normally caused by an entrapment of the lateral femoral cutaneous nerve (LFCN) at the anterior superior iliac spine. In a few cases compression of the nerve in the retroperitoneum has been reported to mimic meralgia paresthetica.CASE DESCRIPTIONA 67-year-old woman presented with a 5-year history of permanent paresthesia

Martin Trummer; Gerhard Flaschka; Frank Unger; Sandro Eustacchio

2000-01-01

150

Assessing the Risk of Disc Heniation Related to Landing Impact Following Long-duration Spacecraft  

NASA Technical Reports Server (NTRS)

Previous research has shown that crewmembers returning on the Space Shuttle have an increased incidence of herniated nucleus pulposus after spaceflight. This increased risk is thought to be related to disc volume expansion due to unloading and prolonged exposure to microgravity. Although there is an increased risk of disc herniation in Space Shuttle astronauts, it is unknown if dynamic landing loads further contribute to the risk of herniation. To determine if dynamic loads increase the risk of incidence, data from crewmembers (excluding cosmonauts) returning on the Soyuz spacecraft will be compared to Space Shuttle astronauts. These data will be obtained from the Lifetime Surveillance of Astronaut Health (LSAH) Project at NASA. Severity and incidence after spaceflight will be mined from the data, and statistical analyses will be used to determine if Soyuz crewmembers have a higher incidence of disc herniation than Space Shuttle crewmembers. The results are expected to show no difference between Space Shuttle and Soyuz crewmembers, indicating that higher dynamic loads on landing and long-duration spaceflight do not significantly increase the risk of disc herniation. If no difference is shown between the two crewmember populations, then disc volume expansion due to microgravity does not significantly increase the risk of injury due to dynamic loads for deconditioned crewmembers. Any risk associated with deconditioning would be primarily due to bone structure changes and resulting bone strength changes. This study is an important first step in determining whether the spinal disc plays a role in injury due to dynamic loads.

Somers, J. T.; Newby, N..; Wells, J.

2014-01-01

151

Repeated microendoscopic discectomy for recurrent lumbar disk herniation  

PubMed Central

OBJECTIVES: To explore the microendoscopic discectomy technique and inclusion criteria for the treatment of recurrent lumbar disc herniation and to supply feasible criteria and technical notes to avoid complications and to increase the therapeutic effect. METHODS: A consecutive series of 25 patients who underwent posterior microendoscopic discectomy for recurrent lumbar disc herniation were included. The inclusion criteria were as follows: no severe pain in the lumbar region, no lumbar instability observed by flexion-extension radiography and no intervertebral discitis or endplate damage observed by magnetic resonance imaging. All patients were diagnosed by clinical manifestations and imaging examinations. RESULTS: Follow-up visits were carried out in all cases. Complications, such as nerve injuries, were not observed. The follow-up outcomes were graded using the MacNab criteria. A grade of excellent was given to 12 patients, good to 12 patients and fair to 1 patient. A grade of excellent or good occurred in 96% of cases. One patient relapsed 3 months after surgery and then underwent lumbar interbody fusion and inner fixation. The numerical rating scale of preoperative leg pain was 7.4± 1.5, whereas it decreased to 2.1±0.8 at 7 days after surgery. The preoperative Oswestry disability index of lumbar function was 57.5±10.0, whereas it was 26.0±8.5 at 7 days after surgery. CONCLUSION: In these cases, microendoscopic discectomy was able to achieve satisfactory clinical results. Furthermore, it has advantages over other methods because of its smaller incision, reduced bleeding and more efficient recovery. PMID:25789521

Hou, Tianyong; Zhou, Qiang; Dai, Fei; Luo, Fei; He, Qingyi; Zhang, Jinsong; Xu, Jianzhong

2015-01-01

152

Cerebral herniation during bacterial meningitis in children  

Microsoft Academic Search

OBJECTIVE--To see whether the incidence of cerebral herniation is increased immediately after lumbar puncture in children with bacterial meningitis and whether any children with herniation have normal results on cranial computed tomography. DESIGN--Retrospective review of case notes; computed tomograms were read again. SETTING--Large paediatric teaching hospital. SUBJECTS--445 children over 30 days old admitted to hospital with bacterial meningitis. MAIN OUTCOME

G Rennick; F Shann; J de Campo

1993-01-01

153

Evaluation of Percutaneous Disc Decompression Using Coblation in Chronic Back Pain With or Without Leg Pain  

Microsoft Academic Search

months post procedure. Eighty patients who presented with dis- cogenic low back pain with or without radicular pain associated with contained disc herniation underwent percutaneous disc decompression using Coblation™ technology (Nucleoplas- ty™) after failing at least 3 months of conserva- tive and injection therapies. Overall, 75% of patients indicated a decrease in their numeric pain scores at 12 months with

Vijay Singh; Chandur Piryani; Katherine Liao

2003-01-01

154

Lumbar Disc Degenerative Disease: Disc Degeneration Symptoms and Magnetic Resonance Image Findings  

PubMed Central

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

Saleem, Shafaq; Rehmani, Muhammad Asim Khan; Raees, Aisha; Alvi, Arsalan Ahmad; Ashraf, Junaid

2013-01-01

155

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

PubMed Central

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

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

2014-01-01

156

Thoracoabdominal herniation--but not as you know it.  

PubMed

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

Wigley, J; Noble, F; King, A

2014-07-01

157

Scrotal Herniation of Bladder: A Case Report  

PubMed Central

Inguinal bladder hernia is a rare clinical condition, with 1–3% of all inguinal hernias involving the bladder. Any portion of the bladder may herniate, from a small portion or a diverticulum to most of the bladder. We present a 55-year-old male with an intermittent right scrotal mass of 6 months’ duration. The mass lesion protruded through the right inguinal canal before voiding and reduced after that. Scrotal sonography revealed a hypoechoic lesion in the scrotum that stretched cranially to the intra-abdominal portion of the bladder. Excretory urography showed a duplicated system in the left kidney and deviation of the left orifice to the right side of the trigon. Finally, cystography illustrated herniation of the bladder to the right scrotum. Surgical repair of the hernia was done with mesh. Follow-up cystography one month postoperatively revealed no herniation. PMID:23645960

Hamidi Madani, Ali; Mohammadi Nikouei, Hossein; Baghani Aval, Hamidreza; Enshaei, Ahmad; Asadollahzade, Ahmad; Esmaeili, Samaneh

2013-01-01

158

Percutaneous diode laser disc nucleoplasty  

NASA Astrophysics Data System (ADS)

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%.

Menchetti, P. P.; Longo, Leonardo

2004-09-01

159

Histologic findings of disc, end plate and neural elements after coblation of nucleus pulposus: an experimental nucleoplasty study  

Microsoft Academic Search

Background contextPartial removal of the nucleus has been shown to decompress herniated discs, relieving pressure on nerve roots and, in some cases, offering relief from disc pain. The nucleoplasty technique builds on earlier surgical approaches that helped validate the strategy of intranuclear tissue removal. Nucleoplasty, a new minimally invasive procedure using patented coblation technology, combines coagulation and ablation for partial

Yung C Chen; Sang-Heon Lee; Yamil Saenz; Norman L Lehman

2003-01-01

160

Intercostal lung herniation - The role of imaging  

PubMed Central

Extrathoracic lung hernias can be congenital or acquired. Acquired hernias may be classified by etiology into traumatic, spontaneous, and pathologic. We present a case of a 40-year-old male with a history of bronchial asthma and a blunt chest trauma who presented complaining of sharp chest pain of acute onset that began after five consecutive days of vigorous coughing. Upon physical examination a well-demarcated deformity overlying the third intercostal space of the left upper anterior hemithorax was revealed. Thoracic CT scan showed that a portion of the anterior bronchopulmonary segment of the left upper lobe had herniated through a chest wall defect. The role of imaging, especially chest computed tomography with multiplanar image reconstructions and maximum (MIP) and minimum intensity projection (MinIP) reformats can clearly confirm the presence of the herniated lung, the hernial sac, the hernial orifice in the chest wall, and exclude possible complications such as lung tissue strangulation. PMID:24967031

Detorakis, Efstathios E.; Androulidakis, Emmanuel

2014-01-01

161

Cecal bascule herniation into the lesser sac.  

PubMed

Cecal bascule is a rare cause of bowel obstruction in which a mobile cecum folds anteriorly and superiorly over the ascending colon. Herein, we present the first case of internal herniation of a cecal bascule into the lesser sac through the foramen of winslow, aiming at discussing radiological findings, differential diagnosis, and surgical management of this uncommon condition. A 75-year-old female presented to the emergency room with an 18-h history of sudden onset sharp, progressively worsening abdominal pain associated with vomiting. Physical exam revealed abdominal distention and epigastric tenderness while initial laboratory tests were unremarkable. Computed tomography of her abdomen and pelvis showed a loop of distended colon within lesser sac without signs of bowel ischemia or perforation. On exploratory laparotomy, a cecal bascule was found herniating into lesser sac via foramen of winslow. Upon reduction, the cecum appeared viable therefore a cecopexy was performed without bowel resection. Unlike cecal volvulus, cecal bascule consists of no axial rotation of the bowel with no mesenteric vascular compromise and therefore ischemia would only occur from intraluminal tension or extraluminal compression from the borders of foramen of winslow. The management of internal herniation of a cecal bascule is always surgical including anatomic resection or cecopexy. PMID:25516868

Makarawo, Tafadzwa; Macedo, Francisco Igor; Jacobs, Michael J

2014-12-16

162

Cecal bascule herniation into the lesser sac  

PubMed Central

Cecal bascule is a rare cause of bowel obstruction in which a mobile cecum folds anteriorly and superiorly over the ascending colon. Herein, we present the first case of internal herniation of a cecal bascule into the lesser sac through the foramen of winslow, aiming at discussing radiological findings, differential diagnosis, and surgical management of this uncommon condition. A 75-year-old female presented to the emergency room with an 18-h history of sudden onset sharp, progressively worsening abdominal pain associated with vomiting. Physical exam revealed abdominal distention and epigastric tenderness while initial laboratory tests were unremarkable. Computed tomography of her abdomen and pelvis showed a loop of distended colon within lesser sac without signs of bowel ischemia or perforation. On exploratory laparotomy, a cecal bascule was found herniating into lesser sac via foramen of winslow. Upon reduction, the cecum appeared viable therefore a cecopexy was performed without bowel resection. Unlike cecal volvulus, cecal bascule consists of no axial rotation of the bowel with no mesenteric vascular compromise and therefore ischemia would only occur from intraluminal tension or extraluminal compression from the borders of foramen of winslow. The management of internal herniation of a cecal bascule is always surgical including anatomic resection or cecopexy. PMID:25516868

Makarawo, Tafadzwa; Macedo, Francisco Igor; Jacobs, Michael J

2014-01-01

163

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

PubMed Central

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

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

2014-01-01

164

Accretion discs  

NASA Astrophysics Data System (ADS)

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.

Abramowicz, Marek A.; Straub, Odele

2014-08-01

165

Lumbar Disk Herniation Surgery: Outcome and Predictors  

PubMed Central

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

Sedighi, Mahsa; Haghnegahdar, Ali

2014-01-01

166

Lumbar disk herniation surgery: outcome and predictors.  

PubMed

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

Sedighi, Mahsa; Haghnegahdar, Ali

2014-12-01

167

Is the outcome of traditional lumbar disc surgery related to the size of the exposure?  

Microsoft Academic Search

Summary The purpose of this study was to evaluate whether wide surgical exposures result in poorer outcome of lumbar disc surgery compared to smaller traditional exposures. The aim was also to assess if a dural tear has any impact on the postoperative clinical outcome. One hundred and twenty-two patients (56 women and 66 men, mean age 40.8 years) with herniated

V. Graver; A. E. Ljunggren; B. Magnæs; M. Loeb; H. Lie

1996-01-01

168

Current and Future Approaches to Lumbar Disc Surgery (A Literature Review)  

Microsoft Academic Search

Herniation may occur anywhere along the spine but most commonly in the lumbar region, usually between the fifth lumbar and first sacral vertebrae (L5-S1). The usual cause is degeneration of the posterior longitudinal ligaments and the annulus fibrosis, frequently occurring in adults 35 years and older. Surgical interventions to treat degenerative disc disease range from the widely accepted microdiscectomy to

Cargill H. Alleyne Jr; Gerald E. Rodts Jr.

169

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

PubMed Central

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.

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

2014-01-01

170

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

PubMed Central

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

Risbud, Makarand V.; Shapiro, Irving. M

2014-01-01

171

Cervical pulmonary herniation due to blunt chest trauma.  

PubMed

Traumatic lung herniation through the superior thoracic aperture rarely occurs. In this case report we present a motor vehicle accident of a 40 year old male victim with cervical lung herniation. After an enormous blunt trauma to the chest, the disrupted and lacerated lung tissue left the thoracic cavity and was pushed into the laryngeal and oral cavity. Extrathoracic post-traumatic lung herniation through the thoracic inlet and connective tissue spaces of the neck into the oral cavity is a unique complication of blunt trauma to the chest, and the post-mortem medico-legal investigations may collect more information about this phenomenon. PMID:22000908

Töro, Klára; Halász, Judit; Marcsa, Boglárka; Biczó, Dávid; Nemeskéri, Agnes

2011-11-01

172

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

173

Standards of Practice: Quality Assurance Guidelines for Percutaneous Treatments of Intervertebral Discs  

SciTech Connect

Percutaneous treatments are used in the therapy of small- to medium-sized hernias of intervertebral discs to reduce the intradiscal pressure in the nucleus and theoretically create space for the herniated fragment to implode inward, thus reducing pain and improving mobility and quality of life. These techniques involve the percutaneous removal of the nucleus pulposus by using a variety of chemical, thermal, or mechanical techniques and consist of removal of all or part of nucleus pulposus to induce more rapid healing of the abnormal lumbar disc. These guidelines are written to be used in quality improvement programs for assessing fluoroscopy- and/or computed tomography-guided percutaneous intervertebral disc ablative techniques.

Kelekis, Alexis D., E-mail: akelekis@med.uoa.gr; Filippiadis, Dimitris K., E-mail: dfilippiadis@yahoo.g [Attikon University Hospital, 2nd Radiology Department (Greece); Martin, Jean-Baptiste, E-mail: jbmartin@cird.c [Geneva University Hospital, Service d'Imagerie Medicale (Switzerland); Brountzos, Elias, E-mail: ebrountz@med.uoa.g [Attikon University Hospital, 2nd Radiology Department (Greece)

2010-10-15

174

Migratory Intradural Disk Herniation and a Strategy for Intraoperative Localization  

PubMed Central

Study Design?Case report. Objective?Describe a case of intradural disk herniation and a method for intraoperative localization. Methods?Intradural disk herniations are uncommon but well described. The diagnosis of these lesions is often difficult, and sometimes they may be diagnosed only through an intradural exploration after an expected disk fragment cannot be located. We report the case of an intradural disk herniation with an additional diagnostic difficulty—a migrated intradural disk. Results?We present the first intraoperative imaging evidence of disk migration and propose a strategy to locate intradural disk fragments prior to durotomy. Conclusion?Intradural disk herniations should be suspected when intraoperative findings are not congruent with imaging findings. An intraoperative myelogram may be helpful. PMID:25648315

Daffner, Scott D.; Sedney, Cara L.; Rosen, Charles L.

2014-01-01

175

Does minimally invasive lumbar disc surgery result in less muscle injury than conventional surgery? A randomized controlled trial  

Microsoft Academic Search

The concept of minimally invasive lumbar disc surgery comprises reduced muscle injury. The aim of this study was to evaluate\\u000a creatine phosphokinase (CPK) in serum and the cross-sectional area (CSA) of the multifidus muscle on magnetic resonance imaging\\u000a as indicators of muscle injury. We present the results of a double-blind randomized trial on patients with lumbar disc herniation,\\u000a in which

Mark ArtsRonald; Ronald Brand; Bas van der Kallen; Geert Lycklama à Nijeholt; Wilco Peul

2011-01-01

176

Ambulatory surgery is safe and effective in radicular disc disease.  

PubMed

Advances in medicine, including diagnostic techniques and therapeutic procedures, have resulted in the ambulatory management of many diseases. A number of surgical procedures previously considered to require hospitalization now are offered on a routine basis as an outpatient or short-stay admission. Although the use of microdiscectomy for the treatment of virgin herniated disc in ambulatory patients has been reported in very limited numbers, it has not been applied to other problems, such as recurrent herniated disc, far lateral disc, or foramenal stenosis. In addition, it only has been used in optimal patients. The authors analyzed a diverse group of patients who underwent outpatient microdiscectomy and found, for most patients studied, hospitalization was not necessary. Seventy-four patients were prospectively studied to determine whether unilateral root decompression for disc or stenosis could be accomplished on an ambulatory basis. Ninety percent of the patients were able to be discharged on the day of surgery. There was no significant morbidity related to the ambulatory approach. The authors also found a significant cost savings for third party reimbursers. PMID:8184345

Bookwalter, J W; Busch, M D; Nicely, D

1994-03-01

177

Treatment of a symptomatic forearm muscle herniation with a mesh graft.  

PubMed

Symptomatic muscle herniations are an unusual cause of upper extremity pain in the athlete that is rarely reported in the literature. Out of 18 reported cases of upper extremity herniations, only 3 were caused by strenuous exertion. This article describes a successful repair of a 21-year-old rock climber's ventral forearm herniation with polypropylene mesh. PMID:23016006

Sanders, Brett S; Bruce, Jeremy; Robertson, Jason

2011-03-01

178

Intraspinal Extradural Cysts Communicating with Adjacent Herniated Disks: Imaging Characteristics and Possible Pathogenesis  

Microsoft Academic Search

Summary: We report two cases of intraspinal extradural cysts communicating with an adjacent herniated disk that we term ''disk cysts.'' These cysts were well defined and homogeneous, and were present in the ventrolateral ex- tradural space adjacent to a lumbar herniated disk. They had rim enhancement on contrast-enhanced MR images, and communication with a herniated disk was revealed by diskography.

Kinuko Kono; Hiroaki Nakamura; Yuichi Inoue; Terue Okamura; Miyuki Shakudo; Ryusaku Yamada

179

Disc protrusion in the childParticular features and comparison with neoplasms  

Microsoft Academic Search

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

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

1997-01-01

180

Non-reclosing pressure relief device for vacuum systems  

DOEpatents

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. 6 figures.

Swansiger, W.A.

1994-02-08

181

Non-reclosing pressure relief device for vacuum systems  

DOEpatents

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.

Swansiger, William A. (Livermore, CA)

1994-01-01

182

Surgical intradiscal decompression without annulotomy in lumbar disc herniation using a coblation device: preliminary results  

Microsoft Academic Search

Annulotomy is a mandatory step to perform intradiscal decompression to resolve a disco radicular conflict. However, this manoeuvre can lead to post surgical complications such as vertebral instability and back pain.

A. P. Fabrizi; M. Zucchelli

183

Spinal cord injury secondary to cervical disc herniation in ambulatory patients with cerebral palsy  

Microsoft Academic Search

Early onset of degeneration of the cervical spine and instability due to sustained abnormal tonicity or abnormal movement of the neck are found in patients with cerebral palsy. An unexplained change or deterioration of neurological function in patients with cerebral palsy should merit the consideration of the possibility of cervical myelopathy due to early degeneration or instability of the cervical

Hyun-Yoon Ko; Insun Park-Ko

1998-01-01

184

Examine for Low Back Pain: The Focus on Inter Vertebral Disc Herniation  

Microsoft Academic Search

Many patients require a medical check?up as an outpatient with the chief complaint of low back pain because the morbidity of low back pain is high. Many cases of acute lumbago resolve spontaneously but some cases shift to chronic lumbago. Low back pain is classified as somatic pain and radicular pain resulting from the lumbar area and other pain originating

Yoshikazu Gembun; Hiromoto Ito

2006-01-01

185

Spontaneous intracranial hypotension due to intradural thoracic osteophyte with superimposed disc herniation: report of two cases  

Microsoft Academic Search

Spontaneous intracranial hypotension (SIH) is a clinical syndrome in which absolute or relative hypovolemia of the cerebrospinal\\u000a fluid (CSF) results in various neurological symptoms. The etiology of spontaneous CSF leaks often remains unknown. However,\\u000a it is believed that the most common cause is the fragility of spinal meninges at the level of radicular nerve root sleeve.\\u000a These tears can be

Zehra Isik Hasiloglu; Bashar Abuzayed; Ahmet Esat Imal; Emin Cagil; Sait Albayram

186

Intercostal lung herniation--the role of imaging.  

PubMed

Extrathoracic lung hernias can be congenital or acquired. Acquired hernias may be classified by etiology into traumatic, spontaneous, and pathologic. We present a case of a 40-year-old male with a history of bronchial asthma and a blunt chest trauma who presented complaining of sharp chest pain of acute onset that began after five consecutive days of vigorous coughing. Upon physical examination a well-demarcated deformity overlying the third intercostal space of the left upper anterior hemithorax was revealed. Thoracic CT scan showed that a portion of the anterior bronchopulmonary segment of the left upper lobe had herniated through a chest wall defect. The role of imaging, especially chest computed tomography with multiplanar image reconstructions and maximum (MIP) and minimum intensity projection (MinIP) reformats can clearly confirm the presence of the herniated lung, the hernial sac, the hernial orifice in the chest wall, and exclude possible complications such as lung tissue strangulation. PMID:24967031

Detorakis, Efstathios E; Androulidakis, Emmanuel

2014-04-01

187

Herniation of a pulmonary emphysematous bulla to contralateral hemithorax.  

PubMed

Herniation of an emphysematous bulla is extremely rare. A 55-year-old male patient presented with complains of shortness of breath and cough for the last 10 years which had exacerbated in the last two days. The patient was a diagnosed case of chronic obstructive pulmonary disease. Chest x-ray showed bilateral hyperinflated lung fields along with loss of lung markings in left upper lobe and a thin white line in right upper lobe suggestive of wall of bulla. High resolution computed tomography of the chest revealed anterior herniation of a pulmonary bulla from left to right side across midline. Patient was put on antibiotics, hydrocortisone and aminophylline by intravenous route and nebulization of steroid and bronchodilator. However, the patient expired after 5 days following admission. PMID:25191377

Akhtar, Jamal; Shameem, Mohammad; Baneen, Ummul; Khan, Nafees Ahmad; Siddiqui, Mohammed Azfar

2011-01-01

188

Herniation of a Pulmonary Emphysematous Bulla to Contralateral Hemithorax  

PubMed Central

Herniation of an emphysematous bulla is extremely rare. A 55-year-old male patient presented with complains of shortness of breath and cough for the last 10 years which had exacerbated in the last two days. The patient was a diagnosed case of chronic obstructive pulmonary disease. Chest x-ray showed bilateral hyperinflated lung fields along with loss of lung markings in left upper lobe and a thin white line in right upper lobe suggestive of wall of bulla. High resolution computed tomography of the chest revealed anterior herniation of a pulmonary bulla from left to right side across midline. Patient was put on antibiotics, hydrocortisone and aminophylline by intravenous route and nebulization of steroid and bronchodilator. However, the patient expired after 5 days following admission. PMID:25191377

Shameem, Mohammad; Baneen, Ummul; Khan, Nafees Ahmad; Siddiqui, Mohammed Azfar

2011-01-01

189

Imbalanced Protein Expression Patterns of Anabolic, Catabolic, Anti-Catabolic and Inflammatory Cytokines in Degenerative Cervical Disc Cells: New Indications for Gene Therapeutic Treatments of Cervical Disc Diseases  

PubMed Central

Degenerative disc disease (DDD) of the cervical spine is common after middle age and can cause loss of disc height with painful nerve impingement, bone and joint inflammation. Despite the clinical importance of these problems, in current publications the pathology of cervical disc degeneration has been studied merely from a morphologic view point using magnetic resonance imaging (MRI), without addressing the issue of biological treatment approaches. So far a wide range of endogenously expressed bioactive factors in degenerative cervical disc cells has not yet been investigated, despite its importance for gene therapeutic approaches. Although degenerative lumbar disc cells have been targeted by different biological treatment approaches, the quantities of disc cells and the concentrations of gene therapeutic factors used in animal models differ extremely. These indicate lack of experimentally acquired data regarding disc cell proliferation and levels of target proteins. Therefore, we analysed proliferation and endogenous expression levels of anabolic, catabolic, ant-catabolic, inflammatory cytokines and matrix proteins of degenerative cervical disc cells in three-dimensional cultures. Preoperative MRI grading of cervical discs was used, then grade III and IV nucleus pulposus (NP) tissues were isolated from 15 patients, operated due to cervical disc herniation. NP cells were cultured for four weeks with low-glucose in collagen I scaffold. Their proliferation rates were analysed using 3-(4, 5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide. Their protein expression levels of 28 therapeutic targets were analysed using enzyme-linked immunosorbent assay. During progressive grades of degeneration NP cell proliferation rates were similar. Significantly decreased aggrecan and collagen II expressions (P<0.0001) were accompanied by accumulations of selective catabolic and inflammatory cytokines (disintegrin and metalloproteinase with thrombospondin motifs 4 and 5, matrix metalloproteinase 3, interleukin-1?, interleukin-1 receptor) combined with low expression of anti-catabolic factor (metalloproteinase inhibitor 3) (P<0.0001). This study might contribute to inhibit inflammatory catabolism of cervical discs. PMID:24804684

Mern, Demissew S.; Beierfuß, Anja; Fontana, Johann; Thomé, Claudius; Hegewald, Aldemar A.

2014-01-01

190

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

PubMed

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

Battal, Bilal; Castillo, Mauricio

2014-02-01

191

Herniation of the spinal cord 38 years after childhood trauma  

Microsoft Academic Search

We report an unusual post-traumatic spinal cord herniation, which became symptomatic 38 years after the trauma. A 44-year-old man presented with a 2-year history of increasing impotence, neuropathic bladder dysfunction and dissociated sensory loss below the level of T6. At the age of 6 years he had a severe blunt spinal injury with transient paraparesis. MRI revealed right lateral and

H. Urbach; B. Kaden; U. Pechstein; L. Solymosi

1996-01-01

192

Cervical lung lobe herniation in dogs identified by fluoroscopy  

PubMed Central

This study aimed to determine the frequency of cervical lung lobe herniation (CLLH) in dogs evaluated fluoroscopically and to identify associated characteristics. Reports of diagnostic procedures and patient summaries from 2008 to 2010 were reviewed retrospectively. Signalment, body weight, duration of cough, presence of heart murmur and airway collapse, and radiographic findings were compared between dogs with and without CLLH. Of the 121 dogs that were examined, CLLH occurred in 85 (70%). The extra-thoracic trachea kinked during herniation in 33 (39%) dogs with CLLH. Collapse of the intra-thoracic trachea (assessed fluoroscopically or bronchoscopically) and collapse of major bronchi (assessed fluoroscopically) were strongly associated with CLLH. Although redundant dorsal tracheal membrane on radiographs was associated with CLLH, extra-thoracic tracheal collapse, assessed fluoroscopically or bronchoscopically, was not. No other associations were found. Cervical lung lobe herniation was present in most dogs evaluated during cough and was associated with intra-thoracic large airway collapse, but not duration of cough. PMID:24155415

Nafe, Laura A.; Robertson, Ian D.; Hawkins, Eleanor C.

2013-01-01

193

Automotive disc brake squeal  

Microsoft Academic Search

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

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

2003-01-01

194

Turbine disc sealing assembly  

DOEpatents

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.

Diakunchak, Ihor S.

2013-03-05

195

Potential regenerative treatment strategies for intervertebral disc degeneration in dogs  

PubMed Central

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

2014-01-01

196

Potential regenerative treatment strategies for intervertebral disc degeneration in dogs.  

PubMed

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

Bach, Frances C; Willems, Nicole; Penning, Louis C; Ito, Keita; Meij, Björn P; Tryfonidou, Marianna A

2014-01-01

197

Intermittent cervical traction for cervical radiculopathy caused by large-volume herniated disks  

Microsoft Academic Search

Objective: To describe the use of intermittent cervical traction in managing 4 patients with cervical radiculopathy and large-volume herniated disks. Clinical Features: Four patients had neck pain radiating to the arm. The clinical examination was typical in all cases for radiculopathy of cervical origin. Magnetic resonance imaging (MRI) of the cervical spine revealed large-volume herniated disks in all patients. Intervention

Constantine Constantoyannis; Demetres Konstantinou; Harry Kourtopoulos; Nicolas Papadakis

2002-01-01

198

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

PubMed

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

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

2015-04-01

199

Incarcerated tubal herniation, an unusual complication of operative laparoscopy and an odd cause of pelvic pain  

Microsoft Academic Search

Tubal herniation after laparoscopic surgery to relieve pelvic pain and adhesions was associated with long-term, chronic pelvic pain in the left lower quadrant. Laparoscopy was performed to diagnose and reduce the herniation. Review of the literature revealed no previous report of this complication.

Donald L. Chatman

2000-01-01

200

Percutaneous Laser Disc Decompression (PLDD): Experience and Results From Multiple Centers and 19,880 Procedures  

NASA Astrophysics Data System (ADS)

In mid-February 1986, Peter Ascher and Daniel Choy performed the first Percutaneous Laser Disc Decompression (PLDD) at the Neurosurgical Department, University of Graz, Graz, Austria. It was planned to deliver 1000 joules with a Nd:YAG laser to a herniated L4-5 disc causing sciatica. At 600 joules the procedure was terminated because the pain was gone. Since then, PLDD has spread all over the world, with procedures being performed in the entire spine except for T1-T4 because these discs do not permit percutaneous access with a needle. The success rate has ranged from 70 to 89%, and the complication rate, chiefly discitis, from 0.3 to 1.0%. When successful, return to normal work averages one week. Long term follow-up to 23 years yields a recurrence rate of 4-5%.

Paolo Tassi, Gian; Choy, Daniel S. J.; Hellinger, Johannes; Hellinger, Stefan; Lee, Sang-Ho

2010-05-01

201

Twin disc gear tooth simulator  

Microsoft Academic Search

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

Martin W. Eusepi; James F. Dill

1994-01-01

202

Herniation of uncus and parahippocampal gyrus: an accidental finding on magnetic resonance imaging of cerebrum  

PubMed Central

Idiopathic herniation of uncus and parahippocampal gyrus into the ambient cistern is a very rare entity, which could be mistaken for other pathology such as tumor. To the best of our knowledge, two prior cases of this kind of herniation have been described. One of these cases was with associated symptomatology and other abnormalities, and the other was characterized as idiopathic. In this case report, we report a case of accidental finding of a herniation of uncus and parahippocampal gyrus into the ambient cistern, without any other accompanying abnormalities, well depicted by magnetic resonance imaging without further necessity for surgical brain intervention. PMID:25610616

Bayat, Michael; Brøndum Frøkjær, Jens

2015-01-01

203

Evidence for shoulder girdle dystonia in selected patients with cervical disc prolapse.  

PubMed

Some patients with cervical disc herniation suffer from persistent nuchal pain and muscle spasms after decompressive surgery despite the lack of clinical and radiological signs for actual spinal root compression. Sonographic examination of the brain in some of these patients showed increased echogenicity of the lentiform nuclei as described in patients with idiopathic dystonia. This has been linked to an altered Menkes protein level and copper metabolism. We suggest a relationship between persistent nuchal pain after adequate cervical disc surgery and dystonic movement disorders. Thirteen patients with persistent nonradicular nuchal pain after at least one cervical disc surgery and without evidence of continuing spinal root compression and 13 age-matched controls were included. All patients had a complete neurological examination, ultrasound, and MRI scan of the brain. In addition, Menkes protein mRNA levels of leucocytes were analyzed in patients and controls. All patients with persistent nuchal pain exhibited a constant tonic unilateral shoulder elevation associated with an ipsilateral hypertrophy of the trapezius muscle. Ultrasound examination showed an increased echogenicity of the lentiform nucleus in one patient unilaterally and in 10 patients bilaterally but in none of the controls. On MRI the T2-values of the lentiform nuclei were found to be higher in patients exhibiting a hyperechogenicity of the lentiform nuclei compared to controls (P = 0.01). In addition, Menkes protein mRNA levels were decreased in patients with cervical disc herniation (P = 0.03). Clinical, neuroimaging, and biochemical findings of this selected patient sample with chronic nuchal pain and muscle spasms after cervical disc surgery resemble alterations in patients with idiopathic cervical dystonia. This suggests a link between both disorders. A peripheral trauma to the nerve roots may precipitate dystonic movements in susceptible patients and chronic dystonic muscle contraction would account for the persistent nuchal pain. PMID:12210860

Becker, Georg; Berg, Daniela; Kruse, Niels; Schröder, Ute; Warmuth-Metz, Monika; Rieckmann, Peter; Naumann, Markus; Reiners, Karlheinz

2002-07-01

204

Traumatic Acute Brain Herniation through the Ear in a Child  

PubMed Central

A seven-year-old girl presented to Sultan Qaboos University Hospital, Oman, with a history of having been hit by a motor vehicle. After this, she had right-sided cerebrospinal fluid otorrhoea, and a week later, brain matter extruded through the right ear. A computed tomography scan of the brain demonstrated a tegmen fracture communicating with the external auditory canal. There was no hearing or facial nerve impairment and an otoscopic examination showed an intact tympanic membrane. She underwent a transcranial repair of the middle cranial fossa base, which revealed a wide dural and bony defect of the tegmen with herniation of the temporal lobe. Repair was made with an intradural patch of artificial dura. The rarity of this type of presentation of temporal bone fracture and its management are discussed. PMID:22912929

Kariyattil, Rajeev; Muthukuttiparambil, Unnikrishnan

2012-01-01

205

CT of lumbar spine disk herniation: correlation with surgical findings  

SciTech Connect

Computed tomography (CT) of the lumbar spine was performed with selectively positioned 5-mm-thick axial cross sections to examine each disk level from the top of the neural foramen to the pedicle of the next caudad vertebra. One hundred consecutive patients with 116 surgical disk explorations were reviewed. There was agreement between the CT and surgical findings in 89 patients (104 explorations) in determination of presence or absence of a herniated nucleus pulposus (HNP). Discrepancy occurred in 12 instances (11 patients): two because of incorrect interpretations, five in previously operated patients, three in spondylolisthesis, and two in spinal stenosis. There were 97 true-positives, eight false-negatives, seven true-negatives, and four false-positives. If nine previously operated patients are excluded from the study, then CT was accurate in detection of presence or absence of an HNP in 93% of the disk explorations.

Firooznia, H.; Benjamin, V.; Kricheff, I.I.; Rafii, M.; Golimbu, C.

1984-03-01

206

A Case of Spontaneous Temporomandibular Joint Herniation into the External Auditory Canal with Clicking Sound  

PubMed Central

A bony defect of the external auditory canal (EAC) and herniation of the temporomandibular joint (TMJ) can be caused by tumorous conditions, inflammation, trauma, and otologic procedures. Spontaneous TMJ herniation into the EAC can be caused by a congenital bony defect known as patent Huschke's foramen, which is a very rare condition. In our case, an objective clicking sound was produced when the patient opened his mouth. A protruding mass was found in the anterior wall of the EAC during mouth closing, and herniation of the TMJ was confirmed with computed tomography. Therefore, we thought the clicking sound of our case could have resulted from spontaneous TMJ herniation through the patent foramen of Huschke. PMID:24653913

Kim, Tae Hyun; Lee, Sun Kyu; Kim, Su Jin

2013-01-01

207

Intrathoracic omental herniation through the esophageal hiatus in a young patient.  

PubMed

We herein present a case of intrathoracic omental herniation through the esophageal hiatus in a young patient. A 21-year-old obese man was asymptomatic, and his chest X-ray demonstrated a large, sharply defined mass. A computed tomography scan of the thorax indicated a large retrocardial mediastinal mass in which the density indicated the presence of fatty tissue judging from the Hounsfield unit range. A thoracotomy was performed under a diagnosis of either mediastinal lipoma or liposarcoma with an encapsulated fatty mass, measuring 17 x 12 x 8 cm in size. The mass, however, proved to be an omental herniation through the esophageal hiatus. It is generally assumed that the major contributing factors leading an individual to develop an omental herniation through the esophageal hiatus include aging and obesity. This is the first report of omental herniation through the esophageal hiatus in a patient still in his twenties. PMID:16164260

Maruyama, Riichiroh; Miyamoto, Tetsuya; Shoji, Fumihiro; Okamoto, Tatsuro; Miyake, Tetsuro; Ichinose, Yukito

2005-08-01

208

A unique perineal herniation of large bladder diverticulum: successful surgical repair through posterior sagittal approach  

Microsoft Academic Search

We report a case of symptomatic perineal herniation of a massive posterior bladder diverticulum following abdominoperineal resection in a 75-year-old man with Crohn's disease and renal failure. Presentation, evaluation, and management issues are discussed.

Michael Gong; Muta M. Issa

1996-01-01

209

Discs gone with the wind?  

Microsoft Academic Search

We examine the conditions imposed on the vertical structure of accretion discs for them to exist. We find that a wind powered by a thermal instability exists in all discs with certain opacity laws. We find that for discs dominated by bremsstrahlung radiation, an inner hole develops below a certain accretion rate, and that for very low accretion rates, discs

G. Shaviv; D. Wickramasinghe; R. Wehrse

1999-01-01

210

Vacuum aperture isolator for retroreflection from laser-irradiated target  

DOEpatents

The disclosure is directed to a vacuum aperture isolator for retroreflection of a laser-irradiated target. Within a vacuum chamber are disposed a beam focusing element, a disc having an aperture and a recollimating element. The edge of the focused beam impinges on the edge of the aperture to produce a plasma which refracts any retroreflected light from the laser's target.

Benjamin, Robert F. (Los Alamos, NM); Mitchell, Kenneth B. (Los Alamos, NM)

1980-01-01

211

Artificial Disc Replacement  

MedlinePLUS

... each other. Most nucleus replacement devices are made of plastic-like (biopolymer) materials. One such material is called ... disc nucleus. Another design consists of a piece of a plastic-like material that coils around to fill the ...

212

Vacuum Technology  

SciTech Connect

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.

Biltoft, P J

2004-10-15

213

Blu-ray disc  

Microsoft Academic Search

A key aspect of any novel optical disc format is compatibility with existing, widely used formats. For BD this means that the optical disc drive must be able to read and write BDs as well as DVDs and CDs, i.e. the dual CD\\/DVD compatibility of present day drives must be enlarged to triple CD\\/DVD\\/BD-compatibility. The main obstacle originates from the

S. Stallinga

2005-01-01

214

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

PubMed Central

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

Wenger, Markus; Markwalder, Thomas-Marc

2010-01-01

215

Vacuum Virtues  

ERIC Educational Resources Information Center

Upright vacuums, like cars, vary in quality, features and performance. Like automobiles, some uprights are reliable, others may be problematic, and some become a problem as a result of neglect or improper use. So, how do education institutions make an informed choice and, having done so, ensure that an upright vacuum goes the distance? In this…

Rathey, Allen

2007-01-01

216

Vacuum Energy  

E-print Network

There appears to be three, perhaps related, ways of approaching the nature of vacuum energy . The first is to say that it is just the lowest energy state of a given, usually quantum, system. The second is to equate vacuum energy with the Casimir energy. The third is to note that an energy difference from a complete vacuum might have some long range effect, typically this energy difference is interpreted as the cosmological constant. All three approaches are reviewed, with an emphasis on recent work. It is hoped that this review is comprehensive in scope. There is a discussion on whether there is a relation between vacuum energy and inertia. The solution suggested here to the nature of the vacuum is that Casimir energy can produce short range effects because of boundary conditions, but that at long range there is no overall effect of vacuum energy, unless one considers lagrangians of higher order than Einstein's as vacuum induced. No original calculations are presented in support of this position. This is not a review of the cosmological constant {\\it per se}, but rather vacuum energy in general, my approach to the cosmological constant is not standard.

Mark D. Roberts

2001-07-22

217

Vacuum mechatronics  

NASA Technical Reports Server (NTRS)

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.

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

1989-01-01

218

The origin of thick discs  

NASA Astrophysics Data System (ADS)

Thick discs are defined to be disc-like components with a scale height larger than that of the classical discs. They are ubiquitous (Yoachim & Dalcanton 2006; Comerón et al. 2011a), they are made of mostly old and metal-poor stars and are most easily detected in close to edge-on galaxies. Their origin has been considered mysterious and several formation theories have been proposed: • The thick disc being formed secularly by thin disc stars heated by disc overdensities such as giant molecular clouds or spiral arms (Villumsen 1985, ApJ, 290, 75) and by stars moved outwards from their original orbits by radial migration mechanisms (Schönrich & Binney 2009). • The thick disc being formed by the heating of the thin disc by satellites (Quinn et al. 1993) and the tidal stripping of them (Abadi et al. 2003). • The thick disc being formed fast and already thick at high redshift in an highly unstable disc. Inside that thick disc, a thin disc would form afterwards as suggested by Elemgreen & Elmegreen (2006). • The thick disc being formed originally thick at high redshift by the merger of gas-rich protogalactic fragments and a thin disc forming afterwards within it (Brook et al. 2007). The first mechanism is a secular evolution mechanism. The time-scale of the second one is dependent on the merger history of the main galaxy. In the two last mechanisms, the thick disc forms already thick in a short time-scale at high redshift. Recent Milky Way studies, (see, e.g., Bovy et al. 2012), have shown indications that there is no discontinuity between the thin and the thick disc chemical and kinematic properties. Instead, those studies indicate the presence of a monotonic distribution of disc thicknesses. This would suggest a secular origin for the Milky Way thick disc. Studies in external galaxies (Yoachim & Dalcanton 2006; Comerón et al. 2011b), have shown that low-mass disc galaxies have thick disc relative masses much larger than those found in large-mass galaxies. Because low-mass galaxies are dynamically younger than their larger counterparts, it seems difficult for their thick discs to have a secular evolution origin, but simulations show that their thick disc masses are compatible with those of a thick disc formed at high redshift. Thus, recent studies seem to indicate that large-mass galaxies have their thick discs formed mainly due to secular evolution and that low-mass galaxies have them formed at high redshift.

Comerón, Sébastien

2015-03-01

219

Transmastoid approach to repair meningoencephalic herniation in the middle ear.  

PubMed

Meningoencephalic herniation (MEH) in the middle ear and mastoid is a rare pathological entity with possible life-threatening complications. We treated 24 patients with a trans-mastoid approach, and the bony defect was closed by heterologous materials positioned in a multilayer fashion. The cause of the bony defect were chronic otitis media with cholesteatoma, iatrogenic, spontaneous and post-traumatic. The major presenting symptoms were meningitis, headache, conductive hearing loss, cerebrospinal fluid (CSF leak), neurologic deficit and pneumoencephalus, and stenosis of a canal wall down cavity. During follow-up, no patient developed complications due to surgery or related to the pathology, and imaging showed a stable occlusion of the bony defect. Different surgical treatments have been proposed to repair MEH, and the choice is based on the localization and size of the bony defect, preoperative auditory function and the presence of a coexisting pathology. We propose the use of collagenous membranes and bone substitutes for reconstruction of the floor of the middle fossa. PMID:23853399

Sergi, B; Passali, G C; Picciotti, P M; De Corso, E; Paludetti, G

2013-04-01

220

Intrathoracic omental herniation through the esophageal hiatus: report of a case.  

PubMed

We report herein an extremely rare case of intrathoracic omental herniation through the esophageal hiatus. In fact, according to our review of the literature, only eight other cases have been reported, most of which were misdiagnosed as mediastinal lipoma after being identified as an intrathoracic mass. We report herein the ninth case of intrathoracic omental herniation through the esophageal hiatus. A 54-year-old obese woman was admitted to our hospital for investigation of a chest roentgenographic abnormality. She was asymptomatic, and her physical examination and laboratory data were all within normal limits. Her chest X-ray demonstrated a large, sharply-defined mass, and a computed tomography scan of the thorax indicated a large mediastinal mass with fat density. A thoracotomy was performed under the diagnosis of a mediastinal lipoma which revealed an encapsulated fatty mass, 10x7.5x6 cm in size, that proved to be an omental herniation through the esophageal hiatus. There was no herniation of the stomach or intestines into the thorax. The esophageal hiatus was repaired after the omental mass and hernia sac had been resected. This case report serves to demonstrate that whenever a mass of fat density is recognized in the lower thorax, an omental herniation should be borne in mind as a possible differential diagnosis. PMID:10211566

Kato, N; Iwasaki, H; Rino, Y; Imada, T; Amano, T; Kondo, J

1999-01-01

221

Percutaneous Coblation Nucleoplasty in Patients with Contained Lumbar Disc Prolapse: 1 Year Follow-Up in a Prospective Case Series  

Microsoft Academic Search

\\u000a \\u000a Background: Nucleoplasty appears a successful minimally-invasive treatment for symptomatic contained disc herniation (protrusion). The\\u000a purpose of this prospective study was to assess the effectiveness of nucleoplasty for alleviating pain and dysfunction in\\u000a our patients.\\u000a \\u000a \\u000a \\u000a Method: All patients who presented with established low back and\\/or leg pain of at least 3 months’ duration were clinically followed\\u000a for 1 year following the

Tariq Sinan; Mehraj Sheikh; Josip Buric; Khalida Dashti; Ali Al-Mukhaimi

222

Vacuum Technology: Vacuum Technology II  

NSDL National Science Digital Library

This is a PDF version of lecture slides that discuss flow regimes of gas. The PDF includes 14 instructional slides demonstrating related concepts in vacuum technology. Keywords: Reynolds' number, Knudsen's number

Rack, Philip D.

223

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

PubMed Central

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.

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

2015-01-01

224

A ventral incisional hernia with herniation of the left hepatic lobe and review of the literature.  

PubMed

Ventral incisional hernias with hepatic herniation are extremely rare. Only six cases have been reported so far in the literature. We report a case of a ventral incisional hernia with hepatic herniation along with a review of the literature. A 70-year-old female patient with a history of coronary artery bypass graft surgery 6?months earlier, was admitted to our hospital with symptoms of epigastric swelling and discomfort for 3?months. On examination, she had a mild tender 5?cm×5?cm epigastric lump and was diagnosed as ventral incisional hernia. Contrast-enhanced CT of the abdomen revealed a ventral hernia with herniation of omentum and left hepatic lobe. The patient underwent onlay mesh repair and is asymptomatic at 1-month follow-up. There is a need for evaluation of risk factors for this type of ventral incisional hernia and to recognise it as a special entity. PMID:25631758

Neelamraju Lakshmi, Harish; Saini, Devendra; Om, Prabha; Bagree, Rajendra

2015-01-01

225

Revival of the Jumping Disc  

ERIC Educational Resources Information Center

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…

Ucke, C.; Schlichting, H-J.

2009-01-01

226

The Chemistry of Optical Discs.  

ERIC Educational Resources Information Center

Explains the chemistry used in compact discs (CD), digital versatile discs (DVD), and magneto-optical (MO) discs focusing on the steps of initial creation of the mold, the molding of the polycarbonate, the deposition of the reflective layers, the lacquering of the CDs, and the bonding of DVDs. (Contains 15 references.) (YDS)

Birkett, David

2002-01-01

227

Abnormalities of the optic disc  

Microsoft Academic Search

The optic disc represents the anterior end of the optic nerve, the most forward extension of the central nervous system (CNS). The optic disc gives a rare glimpse into the CNS. Hence, diseases of the CNS are often manifested on fundus examination. Abnormalities of the optic disc may reflect eye disease (such as glaucoma), problems in development (as in various

Alfredo A. Sadun; Michelle Y. Wang

2011-01-01

228

The DISC Quotient  

NASA Astrophysics Data System (ADS)

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.

Elliott, John R.; Baxter, Stephen

2012-09-01

229

Rotating disc viscometer  

Microsoft Academic Search

A rotating disc viscometer, capable of performing accurate measurements in the critical region of a fluid, is described. The apparatus, developed in the authors' laboratory, allows viscosity measurements to be performed with a very small fluid sample at the desired shear rate.

L. Bruschi; M. Santini; G. Torzo

1984-01-01

230

Vacuum Gauges  

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. Semiconductor manufacturing equipment requires the use of many different types of vacuum gauges. Selection is based on range of process operations and production requirements. This MATEC module explores the theory and functionality of vacuum gauges and provides many examples of different types of gauges. The focus is on understanding the operating ranges and application constraints of each type of gauge. Mathematical equations are used to explain calibration, sensitivity, and overall operations of each type of gauge.

231

Vacuum Waves  

E-print Network

As an example of the unification of gravitation and particle physics, an exact solution of the five-dimensional field equations is studied which describes waves in the classical Einstein vacuum. While the solution is essentially 5D in nature, the waves exist in ordinary 3D space, and may provide a way to test for an extra dimension.

Paul S. Wesson

2012-12-11

232

Safety of carboxymethylcellulose\\/polyethylene oxide for the prevention of adhesions in lumbar disc herniation – consecutive case series review  

Microsoft Academic Search

BACKGROUND: Epidural fibrosis is regarded as a cause of failed back surgery syndrome (FBSS) when excessive adhesional\\/fibrotic scar tissue causes compression, pain or discomfort by tethering of nerve tissue to the surrounding muscle or bone. Fibrosis inhibitors could therefore increase the success rate of spinal surgery and decrease the need for reoperations. In recent years, bio-resorbable gels or films for

Patrick Fransen

2008-01-01

233

Preparation of intact bovine tail intervertebral discs for organ culture.  

PubMed

The intervertebral disc (IVD) is the joint of the spine connecting vertebra to vertebra. It functions to transmit loading of the spine and give flexibility to the spine. It composes of three compartments: the innermost nucleus pulposus (NP) encompassing by the annulus fibrosus (AF), and two cartilaginous endplates connecting the NP and AF to the vertebral body on both sides. Discogenic pain possibly caused by degenerative intervertebral disc disease (DDD) and disc herniations has been identified as a major problem in our modern society. To study possible mechanisms of IVD degeneration, in vitro organ culture systems with live disc cells are highly appealing. The in vitro culture of intact bovine coccygeal IVDs has advanced to a relevant model system, which allows the study of mechano-biological aspects in a well-controlled physiological and mechanical environment. Bovine tail IVDs can be obtained relatively easy in higher numbers and are very similar to the human lumbar IVDs with respect to cell density, cell population and dimensions. However, previous bovine caudal IVD harvesting techniques retaining cartilaginous endplates and bony endplates failed after 1-2 days of culture since the nutrition pathways were obviously blocked by clotted blood. IVDs are the biggest avascular organs, thus, the nutrients to the cells in the NP are solely dependent on diffusion via the capillary buds from the adjacent vertebral body. Presence of bone debris and clotted blood on the endplate surfaces can hinder nutrient diffusion into the center of the disc and compromise cell viability. Our group established a relatively quick protocol to "crack"-out the IVDs from the tail with a low risk for contamination. We are able to permeabilize the freshly-cut bony endplate surfaces by using a surgical jet lavage system, which removes the blood clots and cutting debris and very efficiently reopens the nutrition diffusion pathway to the center of the IVD. The presence of growth plates on both sides of the vertebral bone has to be avoided and to be removed prior to culture. In this video, we outline the crucial steps during preparation and demonstrate the key to a successful organ culture maintaining high cell viability for 14 days under free swelling culture. The culture time could be extended when appropriate mechanical environment can be maintained by using mechanical loading bioreactor. The technique demonstrated here can be extended to other animal species such as porcine, ovine and leporine caudal and lumbar IVD isolation. PMID:22330901

Chan, Samantha C W; Gantenbein-Ritter, Benjamin

2012-01-01

234

Mechanotransduction in intervertebral discs  

PubMed Central

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

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

2014-01-01

235

Biomechanics of Disc Degeneration  

PubMed Central

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

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

2012-01-01

236

Vortices in Astrophysical Discs  

NASA Astrophysics Data System (ADS)

Dynamical theory of astrophysical discs predicts two different kinds of vortices: ``linear'' and ``nonlinear.'' If galactic spiral arms are density waves, linear vortices in the velocity field are predicted at infinitesimal amplitude, and both spirals and vortices grow together at equal rate. The centres of linear vortices lie in the neighborhood of the corotation circle and between spiral arms for both spiral generation mechanisms considered here. Linear vortices (anticyclones), which were predicted on the basis of experiments with rotating shallow water, have been observed in spiral galaxies both when the rotation curve has a velocity jump and when it is smooth. There are at least two kinds of nonlinear vortices which occur at a finite amplitude only: Rossby vortices and nonlinear convection. Rossby vortices are described by a 2-D equation, derived from the 3-D nonlinear hydrodynamical equations, which has both scalar and vector nonlinearities. Rossby vortices are independent of the presence of spiral waves and consist of two kinds: single solitary vortices (cyclones and anticyclones) and double solitary vortices (modons). Nonlinear convection is described by the time-averaged nonlinear 3-D hydrodynamical equations taking into account the vertical structure of the disc. It is caused by nonlinear Reynolds stresses induced by the spiral density wave and has a form of four, large-scale, toroidal vortices separated by the vertical cylindrical surface at corotation and the central plane of the disc.

Fridman, A. M.; Khoruzhii, O. V.

1999-04-01

237

Lumbar disc replacement: update.  

PubMed

Over the last decades, fusion of lumbar spinal motion segments has represented the mainstay of treatment of lumbar degenerative conditions which failed to respond adequately to conservative therapy. Increasing demands and expectations from patients as well as the necessity to avoid fusion related negative side effects such as adjacent level disc degeneration, considerable complication and reoperation rates, cranial facet joint violations, pseudarthrosis and others led to the development of motion preserving technologies such as total lumbar disc replacement (TDR). The first and rudimentary attempts to preserve motion of lumbar motion segments can be dated back to the early 1950s. Over the past two to three decades, a variety of new implants with different motion characteristics have been developed and introduced into the market. Despite of the extensive knowledge which has been gained in this field of research, insurers in the United States have refused to reimburse surgeons due to fear of late complications and reoperations as well as unknown secondary costs, which led to a global decline in the numbers of TDR procedures. The current literature review intends to provide a concise summary of the adequate indications for TDR as well as outcome determining factors and delineate the role of TDR in the currently available armamentarium for the treatment of low back pain (LBP) resulting from degenerative disc disease (DDD) without instabilities or deformities. PMID:25649068

Heider, F C; Mayer, H M; Siepe, C J

2015-06-01

238

Vacuum Technology: Vacuum Technology III  

NSDL National Science Digital Library

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

Rack, Philip D.

239

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

PubMed

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

Aldridge, T; Thomson, A; Ilankovan, V

2015-01-01

240

Six cases of inguinal urinary bladder herniation in entire male domestic rabbits.  

PubMed

Six entire male rabbits, between four and eight years old, were presented with a fluctuant scrotal and/or inguinal swelling resulting from inguinal herniation of the urinary bladder. Concurrent problems included urinary sediment (two rabbits), multiple uroliths (one rabbit) and testicular tumour (one rabbit). All rabbits underwent herniorrhaphy surgery. There was a successful outcome in four of the six cases. PMID:23909767

Thas, I; Harcourt-Brown, F

2013-12-01

241

Enclosed rotary disc air pulser  

DOEpatents

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.

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

242

Initial conditions for disc galaxies  

E-print Network

We present a general recipe for constructing N-body realizations of galaxies comprised of near-spherical and disc components. First, an exact spherical distribution function for the spheroids (halo & bulge) is determined, such that it is in equilibrium with the gravitational monopole of the disc components. Second, an N-body realisation of this model is adapted to the full disc potential by growing the latter adiabatically from its monopole. Finally, the disc is sampled with particles drawn from an appropriate distribution function, avoiding local-Maxwellian approximations. We performed test simulations and find that the halo and bulge radial density profile very closely match their target model, while they become slightly oblate due to the added disc gravity. Our findings suggest that vertical thickening of the initially thin disc is caused predominantly by spiral and bar instabilities, which also result in a radial re-distribution of matter, rather than scattering off interloping massive halo particles.

Paul J. McMillan; Walter Dehnen

2007-04-30

243

Numbered nasal discs for waterfowl  

USGS Publications Warehouse

Numbered nasal discs were successfully used in studies requiring large numbers of individually marked waterfowl. The procedure for constructing these discs is outlined. Blue-winged teal (Anas discors) with 5/8-inch discs, and canvasback (Aythya valisineria) and redhead (A. americana) with 3/4-inch discs can be individually identified up to 50 and 80 yards, respectively, with a gunstock-mounted, 20-power spotting scope. The particular value of these markers is their durability, the number of combinations possible, and the apparent absence of behavioral or mortality influence among such species as the blue-winged teal.

Bartonek, J.C.; Dane, C.W.

1964-01-01

244

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...

245

Disc Replacement for Low Back Pain  

MedlinePLUS

... Map AAPM&R > Patients & Family > Conditions & Treatments > Musculoskeletal > Spine (Neck and Back) > Disc Replacement for Low Back Pain Disc Replacement for Low Back Pain Page Content The evolution of disc replacement surgery may help select patients ...

246

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

PubMed Central

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

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

2014-01-01

247

Degeneration of the intervertebral disc  

Microsoft Academic Search

The intervertebral disc is a cartilaginous structure that resembles articular cartilage in its biochemistry, but morphologically it is clearly different. It shows degenerative and ageing changes earlier than does any other connective tissue in the body. It is believed to be important clinically because there is an association of disc degeneration with back pain. Current treatments are predominantly conservative or,

Jill PG Urban; Sally Roberts

2003-01-01

248

Resonances in retrograde circumbinary discs  

NASA Astrophysics Data System (ADS)

We analyse the interaction of an eccentric binary with a circular coplanar circumbinary disc that rotates in a retrograde sense with respect to the binary. In the circular binary case, no Lindblad resonances lie within the disc and no Lindblad resonant torques are produced, as was previously known. By analytic means, we show that when the binary orbit is eccentric, there exist components of the gravitational potential of the binary which rotate in a retrograde sense to the binary orbit and so rotate progradely with respect to this disc, allowing a resonant interaction to occur between the binary and the disc. The resulting resonant torques distinctly alter the disc response from the circular binary case. We describe results of three-dimensional hydrodynamic simulations to explore this effect and categorize the response of the disc in terms of modes whose strengths vary as a function of binary mass ratio and eccentricity. These mode strengths are weak compared to the largest mode strengths expected in the prograde case where the binary and disc rotate in the same sense. However, for sufficiently high binary eccentricity, resonant torques open a gap in a retrograde circumbinary disc, while permitting gas inflow on to the binary via gas streams. The inflow results in a time varying accretion rate on to the binary that is modulated over the binary orbital period, as was previously found to occur in the prograde case.

Nixon, Chris; Lubow, Stephen H.

2015-04-01

249

Percutaneous discectomy on lumbar radiculopathy related to disk herniation: why under CT guidance? An open study of 100 consecutive patients.  

PubMed

The primary objective of this study conducted on 100 patients is to demonstrate that performing CT-guided percutaneous discectomy for herniated disks results in a significant improvement in pain symptoms at several times (D1, D2, D7, 1 month, 3 months, 6 months). This objective assesses the effectiveness and feasibility of this technique under CT guidance in patients presenting documented lower back pain related to disk herniation that has not improved with appropriate medical treatment. The impact of various factors on the effectiveness of discectomy will also be evaluated. At 1 week, we notes a decrease in average VAS respectively of 71% and 67% in patients treated for posterolateral and foraminal herniated disks; the result for posteromedian herniated disks is only 45% in average decrease. At 6 months post op, 79% of lateralized herniated disks have a satisfactory result (? 70% decrease in pain as compared to initial pain), whereas post median herniated disks had a satisfactory result in only 50% of cases. Percutaneous fine needle discectomy probe under combined CT and fluoroscopic guidance is a minimally invasive spine surgery which should be considered as an alternative to surgery. This technique presents several advantages: the small diameter of the probe used (maximum 16 G or 1.5mm) allows a cutaneous incision of only a few millimeters, and a trans-canal approach can be possible; it also decreases the risk of ligamentary lesion and does not cause an osseous lesion of the posterior arc or of the adjacent muscular structures. PMID:21444169

Amoretti, Nicolas; Hauger, Olivier; Marcy, Pierre-Yves; Amoretti, Marie-Eve; Lesbats, Virginie; Yvonne, Maratos; Ianessi, Antoine; Boileau, Pascal

2012-06-01

250

Spinal cord herniation into pseudomeningocele after traumatic nerve root avulsion: case report and review of the literature  

PubMed Central

We present an extremely rare case of traumatic spinal cord herniation due to a brachial plexus avulsion injury and provide a review of the literature of spinal cord herniation. Spinal cord herniation is an uncommon condition that can occur spontaneously or as a result of surgery or trauma. This condition often presents with symptoms and signs as Brown-Séquard syndrome. Traumatic pseudomeningoceles after a brachial plexus avulsion injury have been reported. But transdural herniation of the spinal cord into this pseudomeningocele is an extremely rare and poorly documented condition. There is only two reports of this condition in a thoracic case. The authors report the case of a 22-year-old man presented with a 2-year history of quadriplegia. He was involved in a motorcycle accident, 3 years prior to his presentation. Four years after the initial right brachial plexus injury, he was not able to walk independently. Magnetic resonance imaging (MRI) and computerized tomography (CT) myelography revealed a lateral pseudomeningocele arising from the right C6–7 and C7–T1 intervetebral foramen and cervical spinal cord herniation into this pseudomeningocele. The patient underwent primary closure of pseudomeningocele to prevent spinal cord reherniation. He can walk with cane and use left arm unrestrictedly at the 2-year follow-up examination. Spinal cord herniation following traumatic nerve root avulsion is extremely rare but it should be considered in the differential diagnosis of patients presenting with delayed myelopathy or Brown-Séquard syndrome. PMID:17987326

Ikuma, Hisanori; Nakanishi, Kazuo; Sugimoto, Yoshihisa; Misawa, Haruo; Takigawa, Tomoaki; Ozaki, Toshifumi

2007-01-01

251

Acute gastric incarceration from thoracic herniation in pregnancy following laparoscopic antireflux surgery  

PubMed Central

Diaphragmatic hernia is a rare complication in pregnancy which due to misdiagnosis or management delays may be life-threatening. We report a case of a woman in the third trimester of pregnancy who presented with sudden onset of severe epigastric and thoracic pain radiating to the back. Earlier in the index pregnancy, she had undergone laparoscopic antireflux surgery (ARS) for a hiatus hernia because of severe gastro-oesophageal reflux. Owing to increasing epigastric pain a CT scan was carried out which diagnosed wrap disruption with gastric herniation into the thoracic cavity and threatened incarceration. This is, to our knowledge, the first report of severe adverse outcome after ARS during pregnancy, with acute intrathoracic gastric herniation. We recommend the avoidance of ARS in pregnancy, and the need to advise women undergoing ARS of the postoperative risks if pregnancy occurs within a few years of ARS. PMID:23378556

Brygger, Louise; Fristrup, Claus Wilki; Harbo, Frederik Severin Gråe; Jørgensen, Jan Stener

2013-01-01

252

Fournier's gangrene secondary to an acutely inflamed appendix herniating into the deep inguinal ring  

PubMed Central

Fournier's gangrene (FG) requires prompt recognition and management. We report the case of a 68-year-old man who presented with extensive pain and purple discolouration from the right iliac fossa to perineum. Computed tomography demonstrated gas within the right hemiscrotum extending into the inguinal canal and right buttock, with a right pelvic fluid and air collection. At debridement necrotic fluid was arising from the superficial inguinal ring so laparotomy was performed, revealing a grossly inflamed appendix herniating into the inguinal canal; a right hemicolectomy was performed. Unfortunately, the patient went into cardiac arrest and passed away on the operating table. Histological analysis demonstrated acute-on-chronic inflammation involving the appendix. The condition where appendicitis is implicated in FG is usually due to retroperitoneal rupture and tracking into the perineal spaces. This is the first case reported of an inflamed appendix herniating into the inguinal canal and thus causing FG. PMID:25829533

Sarmah, Piyush B.; Khan, Mashuk; Zilvetti, Miguel

2015-01-01

253

Swyer–James–MacLeod syndrome with ipsilateral herniation of hyperinflated hyperlucent lung  

Microsoft Academic Search

Swyer–James–MacLeod syndrome is characterised by unilateral hyperlucency on chest radiograph with small or normal-sized lung on the affected side and compensatory hyperinflation of opposite lung. Hyperinflation of the affected lung is a very rarely reported entity. An adult female patient, who presented with exertional breathlessness and diagnosed to have hypoplastic left pulmonary artery with hyperlucent, hyperinflated and herniated left lung

Rajiv Garg; Pallavi Aga; S Saheer; Jabeed P; Abhijeet Singh; Ghulam Hassan; Rajendra Prasad

2011-01-01

254

Swyer–James–MacLeod syndrome with ipsilateral herniation of hyperinflated hyperlucent lung  

PubMed Central

Swyer–James–MacLeod syndrome is characterised by unilateral hyperlucency on chest radiograph with small or normal-sized lung on the affected side and compensatory hyperinflation of opposite lung. Hyperinflation of the affected lung is a very rarely reported entity. An adult female patient, who presented with exertional breathlessness and diagnosed to have hypoplastic left pulmonary artery with hyperlucent, hyperinflated and herniated left lung is described. PMID:22679043

Garg, Rajiv; Aga, Pallavi; Saheer, S; P, Jabeed; Singh, Abhijeet; Hassan, Ghulam; Prasad, Rajendra

2011-01-01

255

Swyer-James-MacLeod syndrome with ipsilateral herniation of hyperinflated hyperlucent lung.  

PubMed

Swyer-James-MacLeod syndrome is characterised by unilateral hyperlucency on chest radiograph with small or normal-sized lung on the affected side and compensatory hyperinflation of opposite lung. Hyperinflation of the affected lung is a very rarely reported entity. An adult female patient, who presented with exertional breathlessness and diagnosed to have hypoplastic left pulmonary artery with hyperlucent, hyperinflated and herniated left lung is described. PMID:22679043

Garg, Rajiv; Aga, Pallavi; Saheer, S; Jabeed, P; Singh, Abhijeet; Hassan, Ghulam; Prasad, Rajendra

2011-01-01

256

Treatment of a symptomatic forearm muscle herniation with a wrap-around fascia lata graft  

Microsoft Academic Search

Muscle herniation in the extremity is a well-recognized cause of symptomatic pain on exertion. Only 17 cases involving the\\u000a upper limb has been previously described, 11 of them involving the anterior compartment of the forearm and only 2 were caused\\u000a by strenuous exertion. Treatment for this condition ranged from nonsurgical, primary closure with palmaris longus interweave,\\u000a formal fasciotomy, to closure

Kamarul A. Khalid; Edward T. Mah

2009-01-01

257

Cervical total disc arthroplasty.  

PubMed

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

Basho, Rahul; Hood, Kenneth A

2012-06-01

258

Double-disc gate valve  

DOEpatents

This invention relates to an improvement in a conventional double-disc gate valve having a vertically movable gate assembly including a wedge, spreaders slidably engaged therewtih, a valve disc carried by the spreaders. When the gate assembly is lowered to a selected point in the valve casing, the valve discs are moved transversely outward to close inlet and outlet ports in the casing. The valve includes hold-down means for guiding the disc-and-spreader assemblies as they are moved transversely outward and inward. If such valves are operated at relatively high differential pressures, they sometimes jam during opening. Such jamming has been a problem for many years in gate valves used in gaseous diffusion plants for the separtion of uranium isotopes. The invention is based on the finding that the above-mentioned jamming results when the outlet disc tilts about its horizontal axis in a certain way during opening of the valve. In accordance with the invention, tilting of the outlet disc is maintained at a tolerable value by providing the disc with a rigid downwardly extending member and by providing the casing with a stop for limiting inward arcuate movement of the member to a preselected value during opening of the valve.

Wheatley, Seth J. (Oak Ridge, TN)

1979-01-01

259

Medical Information on Optical Disc*  

PubMed Central

Optical discs may permit a revolutionary change in the distribution and use of medical information. A single compact disc, similar in size to that used for digital audio recording, can contain over 500 million characters of information that is accessible by a Personal Computer. These discs can be manufactured at a cost lower than that of print on paper, at reasonable volumes. Software can provide the health care professional with nearly instantaneous access to the information. Thus, for the first time, the opportunity exists to have large local medical information collections. This paper describes an application of this technology in the field of Oncology.

Schipma, Peter B.; Cichocki, Edward M.; Ziemer, Susan M.

1987-01-01

260

Cover layer technology and a new hard coat for cartridge-free Blu-ray disc  

NASA Astrophysics Data System (ADS)

Spin coating method for cover layer of Blu-ray Disc (BD) has been studied and a new hard coat resin including antifouling property has been developed. A vacuum chuck was newly designed to minimize the ski-jump effect. 3 mm hard coat layer was stacked onto the 97 mm cover layer by spin coating method.

Kang, Tae-Sik; Han, Mi Young; Lee, Seong-Keun; Jang, Sung Hoon; Hong, Young Jun; Seo, Hun; Lee, Chang-Ho

2004-09-01

261

Cover layer technology and a new hard coat for cartridge-free Blu-ray disc  

Microsoft Academic Search

Spin coating method for cover layer of Blu-ray Disc (BD) has been studied and a new hard coat resin including antifouling property has been developed. A vacuum chuck was newly designed to minimize the ski-jump effect. 3 mm hard coat layer was stacked onto the 97 mm cover layer by spin coating method.

Tae-Sik Kang; Mi Young Han; Seong-Keun Lee; Sung Hoon Jang; Young Jun Hong; Hun Seo; Chang-Ho Lee

2004-01-01

262

Enlivening Physics, a Local Video Disc Project.  

ERIC Educational Resources Information Center

Describes how to make and use an inexpensive video disc of physics demonstrations. Discusses the background, production of the disc, subject of the disc including angular momentum, "monkey and the hunter" experiment, Doppler shift, pressure of a constant volume of gas thermometer, and wave effects, and using the disc in classroom. (YP)

McInerney, M.

1989-01-01

263

THE VACUUM/STEAM/VACUUM PROCESS  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Vacuum/Steam/Vacuum surface intervention pilot plant process was developed. The process was developed for chicken, hot dogs, fruits and vegetables, and catfish. Optimum process conditions were determined as nominally, 138 C saturated steam, vacuum and steam times of 0.1 s except that the final...

264

Imaging of intervertebral disc prostheses.  

PubMed

Disc arthroplasty is the replacement of a painful pathological intervertebral disc by a prosthesis, which, unlike spinal fixation, has the advantage of retaining vertebral mobility in the segment concerned. The success of the procedure is dictated by the indication. The radiologist must look for radiographic arguments indicating or contraindicating fitting an implant, and particularly for the presence of facet arthritis which will prompt the surgeon to choose an arthrodesis. Moreover, radiological information plays a major part in preparing for a surgical procedure, as far as access to the disc via the anterior approach is concerned and assessment by CT angiography of the risk of vascular complications. After insertion, radiological monitoring using dynamic X-ray images checks that the implant is correctly positioned and that mobility is restored. In the long term, it can detect complications related to the prosthesis and premature wear to other points of support such as adjacent discs and the facet joints. PMID:22277706

Amoretti, N; Iannessi, A; Lesbats, V; Marcy, P-Y; Hovorka, E; Bronsard, N; Fonquerne, M-E; Hauger, O

2012-01-01

265

Tissue engineering: A live disc  

NASA Astrophysics Data System (ADS)

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.

Hukins, David W. L.

2005-12-01

266

Disc-based immunoassay microarrays  

Microsoft Academic Search

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 microarrays. This new methodology successfully combined high-density microarrays applied via a piezoelectric inkjet applicator with circular indexing on a polycarbonate disc. As

Horacio Kido; Angel Maquieira; Bruce D. Hammock

2000-01-01

267

Adjacent segment degeneration after single-level anterior cervical decompression and fusion: Disc space distraction and its impact on clinical outcomes.  

PubMed

The purpose of this study was to find whether excessive distraction of the disc space for cage insertion was a risk factor for adjacent segment degeneration (ASD) after anterior cervical decompression and fusion (ACDF). One hundred and sixteen consecutive patients who underwent ACDF for single-level cervical disc herniation between June 2006 and November 2008 were retrospectively reviewed. Preoperative, postoperative and final follow-up disc height (DH), sagittal segmental alignment (SSA), and sagittal alignment of the cervical spine (SACS) were measured and compared between the ASD group and non-ASD group. In 116 patients, ASD was radiographically proven in 28 (24.1%) patients. The clinical outcomes were significantly improved compared to the preoperative scores in both groups. However, the postoperative and final follow-up DH of the ASD group were significantly higher than in the non-ASD group (p<0.05). In addition, the postoperative DH was significantly correlated with the postoperative or final follow-up SSA (p<0.05). However, postoperative DH was not found to significantly correlate with postoperative or final follow-up SACS (p=0.072 and p=0.096, respectively). Multivariate analysis showed that postoperative DH was the most significant risk factor for ASD. The clinical outcomes of ACDF for single-level degenerative cervical disc disease were satisfactory. Postoperative DH (the distracted distance) had the greatest impact on the incidence of ASD. Excessive disc space distraction is a considerable risk factor for the development of radiographic ASD. PMID:25487176

Li, Jia; Li, Yongqian; Kong, Fanlong; Zhang, Di; Zhang, Yingze; Shen, Yong

2015-03-01

268

Vacuum Basics & PumpsVacuum Basics & PumpsVacuum Basics & PumpsVacuum Basics & Pumps Ref: CLC notes (JHU)  

E-print Network

Vacuum Basics & PumpsVacuum Basics & PumpsVacuum Basics & PumpsVacuum Basics & Pumps Ref: CLC notes (JHU) Some graphs courtesy of KJLesker, Edwards, Veeco #12;I. VacuumI. Vacuum 1 atm= 760 torr = 1.0132 bar = 1.013x105 Pa = 14.7 psi Rough Vacuum (RV) 1 torr ­ 760 torrg ( ) Medium Vacuum (MV) 10-5 torr

Liu, Kai

269

Germanium detector vacuum encapsulation  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

270

Prosthetic lumbar disc replacement for degenerative disc disease.  

PubMed

Mechanical articulated device to replace intervertebral disc as a treatment for low back pain secondary to disc degeneration has emerged as a promising tool for selected patients. The potential advantages are prevention of adjacent segment degeneration, maintenance of mobility as well as avoidance of all the complications associated with fusion. The short-term results have been comparable to that of fusion, a few mid-term results have shown mixed outcome, but information on long-term results and performance are not available at present. The rationale for lumbar disc arthroplasty, indications, contraindications, the various artificial devices in the market and the concepts intrinsic to each of them, basic technique of insertion, complications are discussed and a brief summary of our experience with one of the devices is presented. PMID:16565543

Kulkarni, Arvind G; Diwan, Ashish D

2005-12-01

271

Marathon related death due to brainstem herniation in rehydration-related hyponatraemia: a case report  

PubMed Central

Introduction Identifying marathon runners at risk of neurological deterioration at the end of the race (within a large cohort complaining of exhaustion, dehydration, nausea, headache, dizziness, etc.) is challenging. Here we report a case of rehydration-related hyponatraemia with ensuing brain herniation. Case presentation We report the death of runner in his 30's who collapsed in the recovery area following a marathon. Following rehydration he developed a respiratory arrest in the emergency room. He was found to be hyponatraemic (130 mM). A CT brain scan showed severe hydrocephalus and brain stem herniation. Despite emergency insertion of an extraventricular drain, he was tested for brainstem death the following morning. Funduscopy demonstrated an acute-on-chronic papilledema; CSF spectrophotometry did not reveal any trace of oxyhemoglobin or bilirubin, but ferritin levels were considerably raised (530 ng/mL, upper reference value 12 ng/mL), consistent with a previous bleed. Retrospectively it emerged that the patient had suffered from a thunderclap headache some months earlier. Subsequently he developed morning headaches and nausea. This suggests that he may have suffered from a subarachnoid haemorrhage complicated by secondary hydrocephalus. This would explain why in this case the relatively mild rehydration-related hyponatremia may have caused brain swelling sufficient for herniation. Conclusion Given the frequency of hyponatraemia in marathon runners (serum Na <135 mM in about 13%), and the non-specific symptoms, we discuss how a simple screening test such as funduscopy may help to identify those who require urgent neuroimaging. PMID:18163909

Petzold, Axel; Keir, Geoffrey; Appleby, Ian

2007-01-01

272

[Herniation of the cecum and ascending colon through the Winslowi foramen in the bursa omentalis].  

PubMed

Herniation through the foramen of Winslow (HFW) is exceedingly rare, the ileum, coecum or ascending colon is involved mostly. One new case is presented here to illustrate the clinical findings, which are often discreet, and the characteristical radiographic features, which can lead to definitive preoperative diagnosis. Treatment is by surgical reduction of the hernia, resection of non-viable bowel or fixation of coecum and ascending colon. Closure of the foramen is generally considered unnecessary. Without delay in diagnosis and treatment, the former high letality rate of the condition is now nearly zero. PMID:7876025

Villiger, A; Fartab, M; Mayer, M

1994-12-01

273

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

PubMed

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

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

2015-04-01

274

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

PubMed Central

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

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

2015-01-01

275

Debris disc formation induced by planetary growth  

NASA Astrophysics Data System (ADS)

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.

Kobayashi, H.; Löhne, T.

2014-08-01

276

History of cervical disc arthroplasty.  

PubMed

Enthusiasm for cervical disc arthroplasty is based on the premise that motion-preserving devices attenuate the progression of adjacent-segment disease (ASD) in the cervical spine. Arthrodesis, on the other hand, results in abnormal load transfer on adjacent segments, leading to the acceleration of ASD. It has taken several decades of pioneering work to produce clinically relevant devices that mimic the kinematics of the intervertebral disc. The goal of this work is to trace the origins of cervical arthroplasty technology and highlight the attributes of devices currently available in the market. PMID:19722812

Baaj, Ali A; Uribe, Juan S; Vale, Fernando L; Preul, Mark C; Crawford, Neil R

2009-09-01

277

Indian Vacuum Society: The Indian Vacuum Society  

NASA Astrophysics Data System (ADS)

The Indian Vacuum Society (IVS) was established in 1970. It has over 800 members including many from Industry and R & D Institutions spread throughout India. The society has an active chapter at Kolkata. The society was formed with the main aim to promote, encourage and develop the growth of Vacuum Science, Techniques and Applications in India. In order to achieve this aim it has conducted a number of short term courses at graduate and technician levels on vacuum science and technology on topics ranging from low vacuum to ultrahigh vacuum So far it has conducted 39 such courses at different parts of the country and imparted training to more than 1200 persons in the field. Some of these courses were in-plant training courses conducted on the premises of the establishment and designed to take care of the special needs of the establishment. IVS also regularly conducts national and international seminars and symposia on vacuum science and technology with special emphasis on some theme related to applications of vacuum. A large number of delegates from all over India take part in the deliberations of such seminars and symposia and present their work. IVS also arranges technical visits to different industries and research institutes. The society also helped in the UNESCO sponsored post-graduate level courses in vacuum science, technology and applications conducted by Mumbai University. The society has also designed a certificate and diploma course for graduate level students studying vacuum science and technology and has submitted a syllabus to the academic council of the University of Mumbai for their approval, we hope that some colleges affiliated to the university will start this course from the coming academic year. IVS extended its support in standardizing many of the vacuum instruments and played a vital role in helping to set up a Regional Testing Centre along with BARC. As part of the development of vacuum education, the society arranges the participation of expert members on the subject to deliver lectures and take part in devising courses in the universities. IVS publishes a quarterly called the `Bulletin of Indian Vacuum Society' since its inception, in which articles on vacuum and related topics are published. NIRVAT, news, announcements, and reports are the other features of the Bulletin. The articles in the Bulletin are internationally abstracted. The Bulletin is distributed free to all the members of the society. The society also publishes proceedings of national/international symposia and seminars, manuals, lecture notes etc. It has published a `Vacuum Directory' containing very useful information on vacuum technology. IVS has also set up its own website http://www.ivsnet.org in January 2002. The website contains information about IVS, list of members, list of EC members, events and news, abstracts of articles published in the `Bulletin of Indian Vacuum Society', utilities, announcements, reports, membership and other forms which can be completed online and also gives links to other vacuum societies. Our Society has been a member of the executive council of the International Union of Vacuum Science, Techniques and Applications (IUVSTA) and its various committees since 1970. In 1983 IVS conducted an International Symposium on Vacuum Technology and Nuclear Applications in BARC, Mumbai, under the sponsorship of IUVSTA. In 1987 IVS arranged the Triennial International Conference on Thin Films in New Delhi, where more than 200 foreign delegates participated. IVS also hosted the IUVSTA Executive Council Meeting along with the conference. The society organized yet again an International Conference on Vacuum Science and Technology and SRS Vacuum Systems at CAT, Indore in1995. IVS arranges the prestigious Professor Balakrishnan Memorial Lecture in memory of its founder vice-president. Leading scientists from India and abroad in the field are invited to deliver the talks. So far 23 lectures have been held in this series. IVS has instituted the `IVS- Professor D Y Phadke Memorial Prize' in memory of our founder presid

Saha, T. K.

2008-03-01

278

Computer animation via optical video disc  

E-print Network

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 ...

Bender, Walter

1981-01-01

279

Artificial Discs for Lumbar and Cervical Degenerative Disc Disease –Update  

PubMed Central

Executive Summary Objective To assess the safety and efficacy of artificial disc replacement (ADR) technology for degenerative disc disease (DDD). Clinical Need Degenerative disc disease is the term used to describe the deterioration of 1 or more intervertebral discs of the spine. The prevalence of DDD is roughly described in proportion to age such that 40% of people aged 40 years have DDD, increasing to 80% among those aged 80 years or older. Low back pain is a common symptom of lumbar DDD; neck and arm pain are common symptoms of cervical DDD. Nonsurgical treatments can be used to relieve pain and minimize disability associated with DDD. However, it is estimated that about 10% to 20% of people with lumbar DDD and up to 30% with cervical DDD will be unresponsive to nonsurgical treatments. In these cases, surgical treatment is considered. Spinal fusion (arthrodesis) is the process of fusing or joining 2 bones and is considered the surgical gold standard for DDD. Artificial disc replacement is the replacement of the degenerated intervertebral disc with an artificial disc in people with DDD of the lumbar or cervical spine that has been unresponsive to nonsurgical treatments for at least 6 months. Unlike spinal fusion, ADR preserves movement of the spine, which is thought to reduce or prevent the development of adjacent segment degeneration. Additionally, a bone graft is not required for ADR, and this alleviates complications, including bone graft donor site pain and pseudoarthrosis. It is estimated that about 5% of patients who require surgery for DDD will be candidates for ADR. Review Strategy The Medical Advisory Secretariat conducted a computerized search of the literature published between 2003 and September 2005 to answer the following questions: What is the effectiveness of ADR in people with DDD of the lumbar or cervical regions of the spine compared with spinal fusion surgery? Does an artificial disc reduce the incidence of adjacent segment degeneration (ASD) compared with spinal fusion? What is the rate of major complications (device failure, reoperation) with artificial discs compared with surgical spinal fusion? One reviewer evaluated the internal validity of the primary studies using the criteria outlined in the Cochrane Musculoskeletal Injuries Group Quality Assessment Tool. The quality of concealment allocation was rated as: A, clearly yes; B, unclear; or C, clearly no. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to evaluate the overall quality of the body of evidence (defined as 1 or more studies) supporting the research questions explored in this systematic review. A random effects model meta-analysis was conducted when data were available from 2 or more randomized controlled trials (RCTs) and when there was no statistical and or clinical heterogeneity among studies. Bayesian analyses were undertaken to do the following: Examine the influence of missing data on clinical success rates; Compute the probability that artificial discs were superior to spinal fusion (on the basis of clinical success rates); Examine whether the results were sensitive to the choice of noninferiority margin. Summary of Findings The literature search yielded 140 citations. Of these, 1 Cochrane systematic review, 1 RCT, and 10 case series were included in this review. Unpublished data from an RCT reported in the grey literature were obtained from the manufacturer of the device. The search also yielded 8 health technology assessments evaluating ADR that are also included in this review. Six of the 8 health technology assessments concluded that there is insufficient evidence to support the use of either lumbar or cervical ADR. The results of the remaining 2 assessments (one each for lumbar and cervical ADR) led to a National Institute for Clinical Excellence guidance document supporting the safety and effectiveness of lumbar and cervical ADR with the proviso that an ongoing audit of all clinical outcomes be undertaken owing to a lack of long-term outcome data from clinical trials. Regard

2006-01-01

280

512 GB recording on 16-layer optical disc with Blu-ray Disc based optics  

Microsoft Academic Search

We confirmed the feasibility of a 16-layer write once disc based on Blu-ray Disc optics that was fabricated with inorganic recording material Bi-Ge-O. The total capacity of the disc achieved 400 GB and 512 GB per single disc side with BD 1x recording speed utilizing conventional BD technique.

Motohiro Inoue; Atsuko Kosuda; Koji Mishima; Tomoki Ushida; Takashi Kikukawa

2010-01-01

281

512 GB recording on 16-layer optical disc with Blu-ray Disc based optics  

NASA Astrophysics Data System (ADS)

We confirmed the feasibility of a 16-layer write once disc based on Blu-ray Disc optics that was fabricated with inorganic recording material Bi-Ge-O. The total capacity of the disc achieved 400 GB and 512 GB per single disc side with BD 1x recording speed utilizing conventional BD technique.

Inoue, Motohiro; Kosuda, Atsuko; Mishima, Koji; Ushida, Tomoki; Kikukawa, Takashi

2010-06-01

282

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

PubMed

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

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

2014-01-01

283

[Coma and transtentorial herniation syndrome due to acute non-expansive hemispheric lesion].  

PubMed

An 81-year-old woman developed left hemiplegia and coma due to a right hemisphere infarct and died 6 days later. When first seen in coma she had the classical signs of descending central herniation in the diencephalic stage. The CT scan of the third day showed a large hypodense area occupying the superficial and deep territories of the middle and anterior cerebral arteries on the left as well as a frontal cortico-subcortical hypodense area indicative of an older infarct on the opposite hemisphere. No mass effects were apparent. She followed a downhill course with signs of brainstem deterioration. A second CT scan a few hours before death revealed the expected pattern of brain shift and herniations. This case adds to the available evidence showing that the clinical signs of encroachment of supratentorial structures upon the basal forebrain can be reproduced by an acute mono-hemispheral lesion without visible mass effects. It indicates, further, that the role of intracranial displacements in the genesis and short-term prognosis of coma remains an unsettled matter. In at least a few number of cases, diaschisis might play a major role. PMID:8729780

De Oliveira-Souza, R; Benchimol, M

1995-12-01

284

Cervical lung herniation complicating a case of acute asphyxial asthma in a child.  

PubMed

The abrupt onset of respiratory failure secondary to asthma, known as acute asphyxial asthma (AAA) in adults, is uncommonly reported in children. Here, we report a case of a child with the acute onset of respiratory failure consistent with AAA complicated by the finding of a neck mass during resuscitation. This 11-year-old boy with a history of asthma initially presented in respiratory failure with altered mental status after the complaint of difficulty in breathing minutes before collapsing at home. Initially, his respiratory failure was thought to be secondary to status asthmaticus, and treatment was initiated accordingly. However, a neck mass noted during the resuscitation was cause for concern, and other etiologies for his respiratory failure were considered, including an airway obstructing neck mass. After pediatric surgery and anesthesia consultation for intubation and possible tracheostomy placement, general anesthesia was induced in the operating room with an inhaled anesthetic, with prompt resolution of the bronchspasm and decompression of the neck mass. Review of the imaging and clinical course ultimately yielded a diagnosis of cervical lung herniation as the etiology of his neck mass. We report this case of AAA and cervical lung herniation and a review of the literature of these 2 uncommon phenomena in children. PMID:25831031

Martchek, Melissa A; Padilla, Benjamin E; Zonfrillo, Mark R; Friedlaender, Eron Y

2015-04-01

285

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

PubMed

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

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

2015-03-01

286

Degenerative disc and vertebral disease – basic sciences  

Microsoft Academic Search

This article summarizes the pathophysiology of spinal degeneration from a mechanistic basic sciences viewpoint, emphasizing the interdependence of discs and vertebrae. Intervertebral disc degeneration differs from normal ageing by involving physical disruption, typically in the form of annular fissures, prolapse or endplate fracture. Frustrated attempts to heal this large avascular tissue give rise to the typical biological features of disc

Michael A. Adams

2009-01-01

287

Reading of cracked optical discs using Iterative Learning Control  

Microsoft Academic Search

Optical discs, including Compact Discs (CDs), Digital Versatile Discs (DVDs), and Blu-ray Discs (BDs), can get cracked during storage and usage. Such cracks commonly lead to discontinuities in the data track, potentially preventing reading of the data on the disc. The aim of the present paper is to improve tracking performance of the optical disc drive in the presence of

Maarten Steinbuch; Koos van Berkel; George Leenknegt; TAE Oomen; Jeroen van de Wijdeven

2009-01-01

288

Educational Vacuum Trainers  

NSDL National Science Digital Library

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

Hansen, Steve

289

Intramural Sports Ultimate Disc "Hat"  

E-print Network

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

Escher, Christine

290

Circumstellar discs around A stars  

NASA Astrophysics Data System (ADS)

Since the IRAS mission it is known that a couple of nearby young stars are surrounded by dust disks (Aumann 1995); two prominent examples are Vega and \\beta Pictoris. CO radio observations of these stars, carried out to trace the gas component of these disks, revealed a strong depletion of CO (Dent et al. 1995). This has been interpreted as a general gas depletion, and models for the formation of gas-giant planets have been called in question. Detailed disc models concentrating on the discs' gas component show that CO has been selectively depleted in the dusty and gaseous discs by photodissociation and freezing out of CO on the cold dust grain surfaces (Rentzsch-Holm, Holweger & Bertoldi (1998), Kamp & Bertoldi 1998). We will now compare our models with the observation to fix the remaining free parameters. The disc mass, the main free parameter, can be inferred from modeling the infrared excess using dust models with various grain sizes and chemical composition. References: Aumann, H.H. 1985. PASP 97, 885 Dent, W.R.F., et al. 1995. MNRAS 277, L25 Rentzsch-Holm, I., Holweger, H., Bertoldi, F. 1998. ASP Conference Series 132, 275 Kamp, I., Bertoldi, F. 1998. in preparation

Kamp, I.; Holweger, H.; Bertoldi, I.

291

Electromagnetic Levitation of a Disc  

ERIC Educational Resources Information Center

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…

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

2012-01-01

292

Radiation hard vacuum switch  

DOEpatents

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.

Boettcher, Gordon E. (Albuquerque, NM)

1990-01-01

293

Cosmology of Vacuum  

E-print Network

Shortly the vacuum component of the Universe from the geometry point of view and from the point of view of the standard model of physics of elementary particles is discussed. Some arguments are given to the calculated value of the cosmological constant (Zeldovich approximation). A new component of space vacuum (the gravitational vacuum condensate) is involved the production of which has fixed time in our Universe. Also the phenomenon of vacuum selforganization must be included in physical consideration of the Universe evolution.

V. Burdyuzha; G. Vereshkov

2007-12-29

294

Use of cervical spine manipulation under anesthesia for management of cervical disk herniation, cervical radiculopathy, and associated cervicogenic headache syndrome  

Microsoft Academic Search

Objective: To demonstrate the benefits of cervical spine manipulation with the patient under anesthesia as an approach to treating a patient with chronic cervical disk herniation, associated cervical radiculopathy, and cervicogenic headache syndrome. Clinical Features: The patient had neck pain with radiating paresthesia into the right upper extremity and incapacitating headaches and had no response to 6 months of conservative

James Herzog

1999-01-01

295

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

PubMed Central

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

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

2013-01-01

296

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

PubMed

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

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

2013-06-27

297

Vacuum String Field Theory  

Microsoft Academic Search

This is a brief review of vacuum string field theory, a new approach to open string field theory based on the stable vacuum of the tachyon. We discuss the sliver state explaining its role as a projector in the space of half-string functionals. We review the construction of D-brane solutions in vacuum string field theory, both in the algebraic approach

Leonardo Rastelli; Ashoke Sen; Barton Zwiebach

2001-01-01

298

Vacuum Vessel Remote Handling  

E-print Network

FIRE Vacuum Vessel and Remote Handling Overview B. Nelson, T. Burgess, T. Brown, H-M Fan, G. Jones #12;13 July 2002 Snowmass Review: FIRE Vacuum Vessel and Remote Handling 2 Presentation Outline · Vacuum Vessel - Design requirements - Design concept and features - Analysis to date - Status and summary

299

The Classical Vacuum.  

ERIC Educational Resources Information Center

The classical vacuum of physics is not empty, but contains a distinctive pattern of electromagnetic fields. Discovery of the vacuum, thermal spectrum, classical electron theory, zero-point spectrum, and effects of acceleration are discussed. Connection between thermal radiation and the classical vacuum reveals unexpected unity in the laws of…

Boyer, Timothy H.

1985-01-01

300

Modelling the Milky Way disc  

NASA Astrophysics Data System (ADS)

RAVE, SEGUE and Hipparcos data are used to study the dynamics of stars in the extended solar neighbourhood. The asymmetric drift of thin disc dwarfs is studied as a function of colour and metallicity. Linear extrapolation of the data falls within the error bars from Aumer & Binney (2009) for local standard of rest. The observed metallicity dependence of the asymmetric drift is consistent with the known radial metallicity distribution in the disc. Implying the asymmetric drift correction to the SEGUE data allows us to reconstruct the behaviour of the rotation curve of the Milky Way in the extended solar neighbourhood. The rotation curve appears to be essentially flat, giving no hint for a dip just outside the solar radius followed by an increase observed in some other data sets. The data are supplemented by tangent point measurements for the inner rotation curve. Thus a synthetic rotation curve of the Milky Way is obtained. It is fitted by a density model consisting of a D! ehnen bulge, an exponential disc with a hole, and a flattened dark matter halo with either cored isothermal or NFW density profile. In this fitting the parameters are constrained to reproduce the local surface density of the disc and the local volume density of the halo, which are known from local stellar dynamics in the solar neighbourhood. Thus the density model of the Milky Way is reconstructed. The vertical structure of the disc of theMilkyWay is consistent with the model by Just & Jahreiß (2010). Some basic features of distribution functions of the Milky Way and of the dynamical heating are also discussed.

Golubov, Oleksiy

2012-10-01

301

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

NASA Astrophysics Data System (ADS)

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.

Foucart, Francois; Lai, Dong

2014-12-01

302

Sealing arrangement with annular flexible disc  

DOEpatents

Fluid sealing arrangements including an annular shaped flexible disc having enlarged edges disposed within channel-shaped annular receptacles which are spaced from one another. The receptacles form an annular region for contacting and containing the enlarged edges of the disc, and the disc is preloaded to a conical configuration. The disc is flexibly and movably supported within the receptacles so that unevenly distributed relative motion between the components containing the receptacles is accommodated without loss of sealing contact between the edges of the disc and the walls of the receptacles.

Pennell, William E. (Greensburg, PA); Honigsberg, Charles A. (Monroeville, PA)

1983-01-01

303

Factors regulating viable cell density in the intervertebral disc: blood supply in relation to disc height  

PubMed Central

The intervertebral disc is an avascular tissue, maintained by a small population of cells that obtain nutrients mainly by diffusion from capillaries at the disc–vertebral body interface. Loss of this nutrient supply is thought to lead to disc degeneration, but how nutrient supply influences viable cell density is unclear. We investigated two factors that influence nutrient delivery to disc cells and hence cell viability: disc height and blood supply. We used bovine caudal discs as our model as these show a gradation in disc height. We found that although disc height varied twofold from the largest to the smallest disc studied, it had no significant effect on cell density, unlike the situation found in articular cartilage. The density of blood vessels supplying the discs was markedly greater for the largest disc than the smallest disc, as was the density of pores allowing capillary penetration through the bony endplate. Results indicate that changes in blood vessels in the vertebral bodies supplying the disc, as well as changes in endplate architecture appear to influence density of cells in intervertebral discs. PMID:23311982

Boubriak, Olga A; Watson, Natasha; Sivan, Sarit S; Stubbens, Naomi; Urban, Jill P G

2013-01-01

304

Herniated Disk  

MedlinePLUS

... With treatment, most people recover. Treatments include rest, pain and anti-inflammatory medicines, physical therapy, and sometimes surgery. NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases

305

[Innervation of the intervertebral disc].  

PubMed

Until very recently, intervertebral disc innervation was a subject of considerable debate. Nowadays, the introduction of inmunohistochemical techniques associated to specific antibodies and studies with retrograde tracers in nerves have allowed greater understanding of disc innervation in physiological and pathological conditions and also endings characteristics and their patterns of distribution in both situations. The existing controversies regarding structural basis of discogenic pain, have raised the interest of knowing the influence of innervation in back pain from discal origin and its characteristics. Today, we know that pathologic neoinnervation accompanying radial fissures is an important factor in the genesis of discogenic pain; within a complex mechanism in which other neurobiomechemical, inflammatory and biomechanical factors are involved. PMID:23582224

García-Cosamalón, José; Fernández-Fernández, Javier; González-Martínez, Emilio; Ibáñez-Plágaro, Javier; Robla Costales, Javier; Martínez-Madrigal, Milton; López Muñíz, Alfonso; del Valle, Miguel Enrique; Vega, José Antonio

2013-01-01

306

Incidence of basilar invagination in patients with tonsillar herniation? A case control craniometrical study.  

PubMed

A retrospective case-control study based on craniometrical evaluation was performed to evaluate the incidence of basilar invagination (BI). Patients with symptomatic tonsillar herniation treated surgically had craniometrical parameters evaluated based on CT scan reconstructions before surgery. BI was diagnosed when the tip of the odontoid trespassed the Chamberlain's line in three different thresholds found in the literature: 2, 5 or 6.6 mm. In the surgical group (SU), the mean distance of the tip of the odontoid process above the Chamberlain's line was 12 mm versus 1.2 mm in the control (CO) group (p<0.0001). The number of patients with BI according to the threshold used (2, 5 or 6.6 mm) in the SU group was respectively 19 (95%), 16 (80%) and 15 (75%) and in the CO group it was 15 (37%), 4 (10%) and 2 (5%). PMID:25252235

Joaquim, Andrei F; Fernandes, Yvens Barbosa; Mathias, Roger N; Batista, Ulysses C; Ghizoni, Enrico; Tedeschi, Helder; Patel, Alpesh A

2014-09-01

307

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

NASA Technical Reports Server (NTRS)

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.

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

2015-01-01

308

Traumatic Acute Brain Herniation through the Ear in a Child: Concealed compound fracture.  

PubMed

A seven-year-old girl presented to Sultan Qaboos University Hospital, Oman, with a history of having been hit by a motor vehicle. After this, she had right-sided cerebrospinal fluid otorrhoea, and a week later, brain matter extruded through the right ear. A computed tomography scan of the brain demonstrated a tegmen fracture communicating with the external auditory canal. There was no hearing or facial nerve impairment and an otoscopic examination showed an intact tympanic membrane. She underwent a transcranial repair of the middle cranial fossa base, which revealed a wide dural and bony defect of the tegmen with herniation of the temporal lobe. Repair was made with an intradural patch of artificial dura. The rarity of this type of presentation of temporal bone fracture and its management are discussed. PMID:22912929

Kariyattil, Rajeev; Muthukuttiparambil, Unnikrishnan

2012-08-01

309

Thermal cracking in disc brakes  

Microsoft Academic Search

Disc brakes are exposed to large thermal stresses during routine braking and extraordinary thermal stresses during hard braking. High-g decelerations typical of passenger vehicles are known to generate temperatures as high as 900°C in a fraction of a second. These large temperature excursions have two possible outcomes: thermal shock that generates surface cracks; and\\/or large amounts of plastic deformation in

Thomas J. Mackin; Steven C. Noe; K. J. Ball; B. C. Bedell; D. P. Bim-Merle; M. C. Bingaman; D. M. Bomleny; G. J. Chemlir; D. B. Clayton; H. A. Evans; R. Gau; J. L. Hart; J. S. Karney; B. P. Kiple; R. C. Kaluga; P. Kung; A. K. Law; D. Lim; R. C. Merema; B. M. Miller; T. R. Miller; T. J. Nielson; T. M. O'Shea; M. T. Olson; H. A. Padilla; B. W. Penner; C. Penny; R. P. Peterson; V. C. Polidoro; A. Raghu; B. R. Resor; B. J. Robinson; D. Schambach; B. D. Snyder; E. Tom; R. R. Tschantz; B. M. Walker; K. E. Wasielewski; T. R. Webb; S. A. Wise; R. S. Yang; R. S. Zimmerman

2002-01-01

310

Ultrahigh vacuum equipment described  

NASA Astrophysics Data System (ADS)

Ultrahigh vacuum equipment for filming with a blockade value and a substrate at the temperature of liquid nitrogen. The equipment has the following characteristics: (1) the vacuum chamber is exposed to the atmosphere, the lockade valve can maintain a vacuum of 1 to 10 to the -9 power torr for a long period of time; (2) it greatly reduces the working cycle compared to before the blockade valve was installed; and (3) the temperature of the sample substrate in the vacuum chamber can be adjusted continuously between 77 K and room temperature. The ultrahigh vacuum filming equipment China now produces does not have an ultrahigh vacuum valve, when inserting and removing samples, the pump casing is exposed to the atmosphere so that even after the pump has operated for a time, its limited vacuum is 10 to the -8 power torr. A bakeable metallic blockade valve is installed between the vacuum pump intake and the vacuum chamber to form a fliming device. The device is simple, the vacuum is increased several levels, and it can make samples at different substrate temperatures.

Li, Yuzhi; Jing, Shiqun; Peng, Xianhui

1985-10-01

311

Dark Matter in Disc Galaxies  

E-print Network

Recent work on the mass distribution in spiral galaxies, using mainly HI observations, is reviewed. The principal problem is still to determine to what extent the dark matter is important in the inner parts of a galaxy, or in other words, how dominant is the self-gravitation of the disc. Studies of the shapes of rotation curves show that in detail there is sufficient individuality in spiral galaxies to prohibit the construction of ``Universal Rotation Curves''. A detailed account is given of the method of Athanassoula et al. (1987), where swing amplifier criteria are applied to set a range in the mass-to-light ratio of the disc. To restrict this range further, other methods might be useful. For a number of bright spirals the rotation curve drops just outside the optical image, but this feature by itself cannot constrain unambiguously the mass models. The use of velocity dispersions seems a promising way, though the observational problems are hard. Within the uncertainties, discs can be close to ``maximum'', even though a range of values cannot be excluded.

A. Bosma

1998-12-01

312

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

PubMed Central

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

2013-01-01

313

Hydrodynamic instability in eccentric astrophysical discs  

NASA Astrophysics Data System (ADS)

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.

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

2014-12-01

314

Magnetic jets from swirling discs  

NASA Astrophysics Data System (ADS)

A broad swathe of astrophysical phenomena, ranging from tubular planetary nebulae through Herbig-Haro objects, radio galaxy and quasar emissions to gamma-ray bursts and perhaps high-energy cosmic rays, may be driven by magnetically dominated jets emanating from accretion discs. We give a self-contained account of the analytic theory of non-relativistic magnetically dominated jets wound up by a swirling disc and making a magnetic cavity in a background medium of any prescribed pressure, p(z). We solve the time-dependent problem for any specified distribution of magnetic flux P(R, 0) emerging from the disc at z = 0, with any specified disc angular velocity ?d(R). The physics required to do this involves only the freezing of the lines of force to the conducting medium and the principle of minimum energy. In a constant pressure environment, the magnetically dominated cavity is highly collimated and advances along the axis at a constant speed closely related to the maximum circular velocity of the accretion disc. Even within the cavity the field is strongly concentrated towards the axis. The twist in the jet field /<|Bz|> is close to and the width of the jet decreases upwards. By contrast, when the background pressure falls off with height with powers approaching z-4, the head of the jet accelerates strongly and the twist of the jet is much smaller. The width increases to give an almost conical magnetic cavity with apex at the source. Such a regime may be responsible for some of the longest strongly collimated jets. When the background pressure falls off faster than z-4, there are no quasi-static configurations of well-twisted fields and the pressure confinement is replaced by a dynamic effective pressure or a relativistic expansion. In the regimes with rapid acceleration, the outgoing and incoming fields linking the twist back to the source are almost anti-parallel so there is a possibility that magnetic reconnections may break up the jet into a series of magnetic `smoke-rings' travelling out along the axis.

Lynden-Bell, D.

2006-07-01

315

Vacuum pump aids ejectors  

SciTech Connect

The steam ejector/vacuum pump hybrid system has been operating satisfactorily since the summer of 1981. This system has essentially been as troublefree as the all-ejector system and, of course, has provided a substantial cost savings. Construction is currently under way to convert the vacuum system of another crude still which is equipped with steam ejectors and barometric condensers to the hybrid system of steam ejectors, surface condensers, and vacuum pumps. This current project is even more financially attractive because it allows a dirty water cooling tower which serves the barometric condensers to be shut down. Providing a vacuum for crude distillation vacuum towers with this hybrid system is by no means the only application of this technique. Any vacuum system consisting of all steam ejectors would be a candidate for this hybrid system and the resulting savings in energy.

Nelson, R.E.

1982-12-01

316

Enhancing tissue repair in annulus fibrosus defects of the intervertebral disc: analysis of a bio-integrative annulus implant in an in-vivo ovine model.  

PubMed

Annulus fibrosus repair techniques for the intervertebral disc (IVD) address the unsolved problem of reherniation after IVD herniation and might facilitate the development of nucleus pulposus replacement techniques for IVD diseases. This study investigates the suitability of a bio-integrative annulus implant.Standardized box defects were applied to the annulus L3/4 and L4/5 of 16 sheep, followed by randomized insertion of the textile polyglycolic acid/polyvinylidene fluoride annulus implant in one of the defects. Explantation was conducted after 2, 6 and 12 weeks, followed by provocative pressure testing and histological analysis. At 2 weeks' follow-up, all specimens of the control defect group demonstrated uncontained herniated nucleus pulposus tissue in the annulus defects. For the treated specimens, the annulus implant consistently provided an effective barrier for herniating nucleus pulposus tissue, with no implant dislocation at all time-points. After 2 weeks, a homogeneous cell infiltration of the annulus implant was observed, leading to a progressive directional matrix build-up. Repair tissue thickness was significantly stronger with the annulus implant at all follow-ups (p < 0.01). No pronounced foreign body reaction and no difference in the amount of supra-annular scar tissue over the defect sites were observed. The implantation procedure inflicted annulus damage adjacent to the defect. At later time-points, however, no difference in comparison with the control defect group was evident. The investigated biointegrative annulus implant showed promising results with regard to biointegration, enhancement of repair tissue and function as a mechanical barrier in an ovine model. © 2013 The Authors. Journal of Tissue Engineering and Regenerative Medicine published by John Wiley & Sons, Ltd. PMID:24227682

Hegewald, Aldemar Andres; Medved, Fabian; Feng, Daxiong; Tsagogiorgas, Charalambos; Beierfuß, Anja; Schindler, Genevieve Ama Kyremaa; Trunk, Marcus; Kaps, Christian; Mern, Demissew Shenegelegn; Thomé, Claudius

2015-04-01

317

Physical Vacuum in Superconductors  

E-print Network

Although experiments carried out by Jain et al. showed that the Cooper pairs obey the strong equivalence principle, The measurement of the Cooper pairs inertial mass by Tate et al. revealed an anomalous excess of mass. In the present paper we interpret these experimental results in the framework of an electromagnetic model of dark energy for the superconductors' vacuum. We argue that this physical vacuum is associated with a preferred frame. Ultimately from the conservation of energy for Cooper pairs we derive a model for a variable vacuum speed of light in the superconductors physical vacuum in relation with a possible breaking of the weak equivalence principle for Cooper pairs.

Clovis Jacinto de Matos

2009-08-31

318

NSLS II Vacuum System  

SciTech Connect

National Synchrotron Light Source II, being constructed at Brookhaven, is a 3-GeV, 500 mA, 3rd generation synchrotron radiation facility with ultra low emittance electron beams. The storage ring vacuum system has a circumference of 792 m and consists of over 250 vacuum chambers with a simulated average operating pressure of less than 1 x 10{sup -9} mbar. A summary of the update design of the vacuum system including girder supports of the chambers, gauges, vacuum pumps, bellows, beam position monitors and simulation of the average pressure will be shown. A brief description of the techniques and procedures for cleaning and mounting the chambers are given.

Ferreira, M.; Doom, L.; Hseuh, H.; Longo, C.; Settepani, P.; Wilson, K.; Hu, J.

2009-09-13

319

Vacuum probe surface sampler  

NASA Technical Reports Server (NTRS)

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.

Zahlava, B. A. (inventor)

1973-01-01

320

On the warping of Be star discs  

E-print Network

The theory of radiatively-induced warps in accretion discs is applied to the discs of Be stars. It is found that these discs may develop warps in their inner regions, although once the warp amplitude is large enough then the interaction between the disc and fast radiatively-driven wind will determine its evolution. The warping is shown to be more important for later than earlier B stars. Although the interaction of the fast-wind with the disc will limit the amplitude of the warp, it cannot drive the warp radially outwards, and so the radial evolution of the warp depends on the dominant advective process within the disc. Typical timescales associated with growing modes are shown to be short, of the order of days-weeks, although these are not likely to be the timescales inferred from observations of line-profile variations which are much longer, of the order of years.

John M. Porter

1998-05-26

321

Close-packing of growing discs  

SciTech Connect

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.

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

1988-12-01

322

Capillary hemangioma of the cervical intervertebral disc  

Microsoft Academic Search

An anterior cervical decompression and fusion operation was complicated by extensive bleeding from the disc space. Histopathological\\u000a evaluation of the resected specimen revealed the diagnosis as the very first reported case of capillary hemangioma in intervertebral\\u000a disc space. Retrospective review of the preoperative MRI demonstrated supporting findings of a capillary hemangioma within\\u000a the cervical intervertebral disc.

Ahmet Cetinkal; Ahmet Colak; Kivanc Topuz; Cem Atabey; Ufuk Berber

2011-01-01

323

Liquid immersion deep-UV optical disc mastering for high data capacity ROM discs  

Microsoft Academic Search

In this paper we describe the liquid immersion mastering technique and its application to the mastering of ROM discs for the Blu-ray Disc system and for ROM discs with considerably higher data densities. Replicated 25GB BD-ROM discs were evaluated using a standard blue test player (lambda=405nm, NA=0.85). A bottom jitter value with limit equalizer of less than 5% was measured.

Jaap H. M. Neijzen; Erwin R. Meinders; Marius I. Boamfa; Dianyong Chen

2005-01-01

324

On the evolution of the protolunar disc.  

PubMed

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

Ward, William R

2014-09-13

325

Unilateral pupillary mydriasis from nebulized ipratropium bromide: A false sign of brain herniation in the intensive care unit.  

PubMed

Although there are many causes of anisocoria in the intensive care setting, the development of unilateral mydriasis in patients with intracranial hemorrhage or tumor is a neurological emergency, as it may herald the onset of uncal herniation. We describe two patients with a hemiparesis from neurosurgical disorder who subsequently developed a fixed and dilated pupil. The pupillary abnormality was caused by nebulized ipratropium bromide in both cases, and resolved when the medication was discontinued. Nebulized ipratropium may leak from the mask into ipsilateral eye and cause mydriasis in patients with facial weakness. This benign cause of anisocoria in the intensive care setting is distinguished from uncal herniation by the laterality of neurologic findings, and lack of mental status change, ptosis, and extraocular movement impairment. PMID:24701070

Chaudhry, Priyanka; Friedman, Deborah I; Yu, Wengui

2014-03-01

326

Intravenous contrast-enhanced CT of the postoperative lumbar spine: improved identification of recurrent disk herniation, scar, arachnoiditis, and diskitis  

SciTech Connect

Unsuccessful relief of symptoms after back surgery is usually attributable to hypertrophic extradural scar or recurrent herniated disk. Their clinical and myelographic differentiation is difficult, yet important because reoperation is not always beneficial for scar removal. This article examines the usefulness of intravenous contrast-enhanced computed tomography for this problem. Forty-five postsurgical patients were studied; eight had subsequent surgery. In the four with hypertrophic scars, intravenous contrast enhancement of the scar allowed its recognition in each case; in the four with hypertrophic scars, intravenous contrast enhancement of the scar allowed its recognition in each case; in the four with recurrent disk herniation, nonenhancement of the extruded disk allowed its recognition in three. In the other 37 patients who were not reoperated, 33 were believed to have scar on the basis of contrast enhancement. The method seems promising for more accurate evaluation of failed back surgery, including the recognition of diskitis.

Teplick, J.G.; Haskin, M.E.

1984-10-01

327

Delayed repair in a case of forearm fascial muscle herniation using non-cross-linked acellular porcine dermal matrix.  

PubMed

The options for treatment of symptomatic muscle herniation in the limbs traditionally include fasciotomy, direct repair, tendon weave graft (palmaris longus), fascial graft (tensor fascia lata), and synthetic mesh (prolene). A recent case report has described the use of acellular cadaveric dermal matrix to reconstruct fascial defects in 2 cases. We describe the use of Strattice, a non-cross-linked acellular porcine dermal matrix, as a fascial underlay graft in a case of symptomatic upper limb muscle herniation. We propose that Strattice has the advantages over cadaveric dermal matrices in terms of avoiding the use of human donor tissue. It has suitable tensile properties to be used for reconstructing fascial defects. PMID:22913999

Hartmann, Christoph E A; Branford, Olivier A; Floyd, David

2012-09-01

328

Large disc intermediate precedes formation of apolipoprotein A-I DMPC small discs  

PubMed Central

Small ~8.5 nm discs formed spontaneously when and dimyristoyl phosphatidylcholine (DMPC) large unilamellar vesicles (LUVs) were incubated with apolipoprotein A-I (apoA-I) (100:1 molar ratio). However, in a time course study, the transient production of ~11 nm large discs was detected and isolated by gel filtration. The intermediate large discs contained three apoA-I molecules and were stable over time; but, when additional apoA-I was added they formed small discs containing two molecules of apoA-I. The reaction kinetics of apoA-I with DMPC LUVs was monitored by fluorescence resonance energy transfer and two phases were observed, supporting the presence of the intermediate in the formation of small discs. The lipid dynamics of LUVs and discs were assayed revealing the presence of sequestered lipid-protein domains upon apoA-I binding to DMPC LUVs. In addition, the lipids in the intermediate large discs were more constrained than those in the small discs. We propose that apoA-I binds with DMPC LUVs to form small lipid-protein domains on the LUV, then the domains are released to form large discs, which can mature in the presence of additional apoA-I to form small discs. Thus, the formation of small apoA-I lipid discs proceeds through the formation of a large disc intermediate. PMID:17474718

Zhu, Keng; Brubaker, Gregory; Smith, Jonathan D.

2008-01-01

329

Total Disc Arthroplasty for Treating Lumbar Degenerative Disc Disease  

PubMed Central

Study Design Lumber disc arthroplasty is a technological advancement that has occurred in the last decade to treat lumbar degenerative disk diseases. Purpose The aim of this retrospective study was to establish the impact and outcomes of managing patients with lumbar degenerative disk disease who have been treated with lumbar total disc arthroplasty (TDA). Overview of Literature Several studies have shown promising results following this surgery. Methods We reviewed the files of 104 patients at the Department of Neurosurgery in Colmar (France) who had been operated on by lumbar spine arthroplasty (Prodisc) between April 2002 and October 2008. Results Among the 104 patients, 67 were female and 37 were male with an average age of 33.1 years. We followed the cases for a mean of 20 months. The most frequent level of discopathy was L4-L5 with 62 patients (59.6%) followed by L5-S1 level with 52 patients (50%). Eighty-three patients suffered from low back pain, 21 of which were associated with radiculopathy. The status of 82 patients improved after surgery according to the Oswestry Disability Index score, and 92 patients returned to work. Conclusions The results indicate that TDA is a good alternative treatment for lumbar spine disk disease, particularly for patients with disabling and chronic low back pain. This technique contributes to improve living conditions with correct patient selection for surgery. PMID:25705336

2015-01-01

330

Vacuuming radioactive sludge  

SciTech Connect

Vacuuming an estimated 55 cubic yards of radioactive sludge from the floor of Hanford's K East Basin was a complicated process. Workers stood on grates suspended above the 20-foot deep basin and manipulated vacuuming equipment at the end of long poles--using underwater cameras to guide their work.

2006-10-16

331

Vacuum Energy Decay  

E-print Network

The problem of the vacuum energy decay is studied through the analysis of the vacuum survival amplitude ${\\mathcal A}(z, z')$. Transition amplitudes are computed for finite time-span, $Z\\equiv z^\\prime-z$, and their {\\em late time} behavior is discussed up to first order in the coupling constant, $\\l$.

Enrique Álvarez; Roberto Vidal

2011-11-09

332

Modeling Vacuum Arcs  

Microsoft Academic Search

We are developing a model of vacuum arcs to describe vacuum breakdown in 805 MHz systems, however the basic mechanisms at work should apply to other applications. The model assumes: 1) that arcs develop as a result of mechanical failure of the surface due to Coulomb explosions, 2) this is followed by ionization of fragments by field emitted currents and

J. Norem; Z. Insepov; Th. Proslier; D. Huang; S. Mahalingam; S. Veitzer

2010-01-01

333

Working in a Vacuum  

ERIC Educational Resources Information Center

In this article, the author discusses several myths about vacuum cleaners and offers tips on evaluating and purchasing this essential maintenance tool. These myths are: (1) Amps mean performance; (2) Everyone needs high-efficiency particulate air (HEPA): (3) Picking up a "bowling ball" shows cleaning power; (4) All vacuum bags are the same; (5)…

Rathey, Allen

2005-01-01

334

Microfabricated triggered vacuum switch  

DOEpatents

A microfabricated vacuum switch is disclosed which includes a substrate upon which an anode, cathode and trigger electrode are located. A cover is sealed over the substrate under vacuum to complete the vacuum switch. In some embodiments of the present invention, a metal cover can be used in place of the trigger electrode on the substrate. Materials used for the vacuum switch are compatible with high vacuum, relatively high temperature processing. These materials include molybdenum, niobium, copper, tungsten, aluminum and alloys thereof for the anode and cathode. Carbon in the form of graphitic carbon, a diamond-like material, or carbon nanotubes can be used in the trigger electrode. Channels can be optionally formed in the substrate to mitigate against surface breakdown.

Roesler, Alexander W. (Tijeras, NM); Schare, Joshua M. (Albuquerque, NM); Bunch, Kyle (Albuquerque, NM)

2010-05-11

335

Minimally Invasive Endourological Techniques may Provide a Novel Method for Relieving Urinary Obstruction due to Ureterosciatic Herniation  

PubMed Central

Ureterosciatic herniation, the protrusion of the hernia sac through the sciatic foramen, is an extremely rare cause of ureteral obstruction. We describe a case revealed by severe left back pain in a 72-year-old female. She was referred to our hospital for urological assessment of left hydronephrosis observed by ultrasonography. Intravenous ureterography (IVU) showed findings compatible with a left sciatic ureter, a dilated ureter with a fixed kinking, which is known as the ‘curlicue’ sign. We decided to attempt recovery of the herniated ureter using a retrograde approach. Ureteral stent placement was performed to decompress the dilated upper urinary tract. The ureterosciatic hernia was relieved with the passage of a flexible guide wire and a double-pigtail stent. Three months after ureteral stenting, she refused continuing to have an indwelling stent and the stent was removed. Thereafter, IVU revealed recurrent ureterosciatic hernia; however, there was no hydroureter or hydronephrosis. The patient is currently being under observation for 6 years after stenting and continues to be without hydronephrosis or symptoms. Placement of an internal stent possibly provides the rigidity to the ureter, thereby reducing the hernia and urinary obstruction. In the previous reports, most symptomatic patients have been treated surgically, with conservative therapy reserved for asymptomatic patients. For the patient who is elderly or a poor surgical candidate, retrograde stenting may provide safe reduction and efficacious treatment. This endourological approach provides a minimally invasive means for the management of urinary obstruction caused by ureterosciatic herniation.

Kato, Tomonori; Komiya, Akira; Ikeda, Ryoichi; Nakamura, Takeshi; Akakura, Koichiro

2015-01-01

336

Minimally Invasive Endourological Techniques may Provide a Novel Method for Relieving Urinary Obstruction due to Ureterosciatic Herniation.  

PubMed

Ureterosciatic herniation, the protrusion of the hernia sac through the sciatic foramen, is an extremely rare cause of ureteral obstruction. We describe a case revealed by severe left back pain in a 72-year-old female. She was referred to our hospital for urological assessment of left hydronephrosis observed by ultrasonography. Intravenous ureterography (IVU) showed findings compatible with a left sciatic ureter, a dilated ureter with a fixed kinking, which is known as the 'curlicue' sign. We decided to attempt recovery of the herniated ureter using a retrograde approach. Ureteral stent placement was performed to decompress the dilated upper urinary tract. The ureterosciatic hernia was relieved with the passage of a flexible guide wire and a double-pigtail stent. Three months after ureteral stenting, she refused continuing to have an indwelling stent and the stent was removed. Thereafter, IVU revealed recurrent ureterosciatic hernia; however, there was no hydroureter or hydronephrosis. The patient is currently being under observation for 6 years after stenting and continues to be without hydronephrosis or symptoms. Placement of an internal stent possibly provides the rigidity to the ureter, thereby reducing the hernia and urinary obstruction. In the previous reports, most symptomatic patients have been treated surgically, with conservative therapy reserved for asymptomatic patients. For the patient who is elderly or a poor surgical candidate, retrograde stenting may provide safe reduction and efficacious treatment. This endourological approach provides a minimally invasive means for the management of urinary obstruction caused by ureterosciatic herniation. PMID:25849669

Kato, Tomonori; Komiya, Akira; Ikeda, Ryoichi; Nakamura, Takeshi; Akakura, Koichiro

2015-01-01

337

Pharmacological mydriasis and optic disc examination  

PubMed Central

AIM—To determine whether pharmacological mydriasis leads to a significant difference in interobserver agreement of optic disc measurement compared with examination without mydriasis.?METHOD—A cross sectional study was performed with a pair of observers examining the optic disc of two randomised groups of patients, one group before diagnostic mydriasis, and the other afterwards. Horizontal and vertical disc diameters and cup/disc ratios were measured with a 78 dioptre lens. The study was repeated with another observer pair and two further groups of patients.?RESULTS—In study A 86 subjects were examined in total (52 without and 34 with mydriasis). In study B 87 subjects were examined (45 without and 42 with mydriasis). The 95% limits of agreement of the cup/disc ratio measurement differences were significantly larger without mydriasis (p<0.001 for all studies (F test)). For both studies examination after mydriasis gave significantly greater agreement for vertical and horizontal cup/disc ratios. The cases with good agreement (0.1 difference or better) for vertical cup/disc ratios were 37/52 (72%) and 34 /45 (76%) without mydriasis and 33/34 (97%) and 40/42 (95%) respectively with mydriasis. Similar differences were recorded for horizontal cup/disc ratios. Disc diameter measurement results showed similar differences in study A but were not affected by mydriasis in study B.?CONCLUSIONS—Examination of the optic disc without pharmacological mydriasis gives significantly poorer interobserver agreement. In this study, the mean 95% limits of agreement values for all cup/disc ratio values were 0.27 for examination without mydriasis and 0.13 for examination with mydriasis. A measure outside these limits would suggest a real difference. This study indicates that mydriasis is important for reproducible clinical examination in glaucoma.?? PMID:10906099

Kirwan, J.; Gouws, P.; Linnell, A.; Crowston, J.; Bunce, C.

2000-01-01

338

Theory of Black Hole Accretion Discs  

NASA Astrophysics Data System (ADS)

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.

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

2010-08-01

339

Transcalvarial brain herniation volume after decompressive craniectomy is the difference between two spherical caps.  

PubMed

Decompressive craniectomy (DC) is a surgical procedure used to relieve severely increased intracranial pressure (ICP) by removing a portion of the skull. Following DC, the brain expands through the skull defect created by DC, resulting in transcalvarial herniation (TCH). Traditionally, people measure only changes in the ICP but not in the intracranial volume (ICV), which is equivalent to the volume of TCH (VTCH), in patients undergoing DC. We constructed a simple model of the cerebral hemispheres, assuming the shape of the upper half of a sphere with a radius of 8cm. We hypothesized that the herniated brain following DC also conforms to the shape of a spherical cap. Considering that a circular piece of the skull with a radius of a was removed, VTCH is the volume difference between 2 spherical caps at the operated side and the corresponding non-operated side, which represents the pre-DC volume underneath the removed skull due to the bilateral symmetry of the skull and the brain. Subsequently, we hypothesized that the maximal extent of TCH depends on a because of the biomechanical limitations imposed by the inelastic scalp. The maximum value of VTCH is 365.0mL when a is 7.05cm and the height difference between the spherical caps (?h) at its maximum is 2.83cm. To facilitate rapid calculation of VTCH, we proposed a simplified estimation formula, VˆTCH=12A(2)?h, where A=2a. With the a value ranging between 0 and 7cm, the ratio between VˆTCH and VTCH ranges between 0.77 and 1.27, with different ?h values. For elliptical skull defects with base diameters of A and C, the formula changes to VˆTCH=12AC?h. If our hypothesis is correct, surgeons can accurately calculate VTCH after DC. Furthermore, this can facilitate volumetric comparisons between the effects of DCs in skulls of varying sizes, allowing quantitative comparisons between ICVs in addition to ICPs. PMID:25583637

Liao, Chun-Chih; Tsai, Yi-Hsin; Chen, Yi-Long; Huang, Ke-Chun; Chiang, I-Jen; Wong, Jau-Min; Xiao, Furen

2015-03-01

340

Are all young stars disc accretors?  

E-print Network

We now understand how low mass stars evolve through cloud collapse and disc accretion, but whether higher mass stars are also disc accretors is as yet unknown. Spectropolarimetry observations can help in answering this basic question, as they probe the first few stellar radii around young stars.

Jorick S. Vink; Janet E. Drew; Tim J. Harries; Rene D. Oudmaijer

2001-10-05

341

Transmural migration of gastrostomy tube retention discs  

Microsoft Academic Search

Background Accidental dislodgment is one of the most frequent causes of avoidable cost and consternation related to gastrostomy tubes. The Sacks–Vine gastrostomy tube, inserted in an antegrade fashion by a percutaneous technique, is extremely stable due to the construction of its disc retention device. However, transmural migration of the retention disc is a known severe delayed complication associated with this

AnneMarie Cahill; Kevin M. Baskin; Robin D. Kaye; Charles R. Fitz; Richard B. Towbin

2004-01-01

342

Precision manufacture of optical disc master stampers  

E-print Network

industry term for the mold used to replicate polymer compact discs (CDs) in an injection molding device are not required, and a ceramic master is used directly as a stamper for injection molding. In the new process and photoresist, this nickel stamper can be used in an injection molding system to replicate polymer discs

343

Counterrotating stars in simulated galaxy discs  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

344

The tidal disruption of protoplanetary accretion discs  

E-print Network

In this paper we revisit the problem of the tidal interaction occuring between a protostellar accretion disc and a secondary point mass following a parabolic trajectory. We model the disc response analytically and we compare our results with three-dimensional SPH simulations. Inviscid as well as viscous hydrodynamics is considered. We show that in a viscous system the response derived from inviscid considerations is predominant even for the highest estimates of an anomalous disc shear viscosity. The angular momentum lost from the disc during the encounter is derived from linear theory, for distant fly-bys, as well as the changes to the disc orientation expected in non-coplanar encounters. It is shown that the target discs can become warped and precess by a small amount during non-coplanar encounters. This small precession is shown to give rise to a relative tilt of the disc which is always more important for determining its final orientation than is the change to the orbital inclination. We discuss the implications of our results for protostellar accretion discs and planetary systems.

John D. Larwood

1997-05-30

345

Rapid evolution of the innermost dust disc of protoplanetary discs surrounding intermediate-mass stars  

NASA Astrophysics Data System (ADS)

We derived the intermediate-mass (?1.5-7 M?) disc fraction (IMDF) in the near-infrared JHK photometric bands as well as in the mid-infrared (MIR) bands for young clusters in the age range of 0 to ˜10 Myr. From the JHK IMDF, the lifetime of the innermost dust disc (˜0.3 au; hereafter the K disc) is estimated to be ˜3 Myr, suggesting a stellar mass (M*) dependence of K-disc lifetime (?1.5-7 M?). However, from the MIR IMDF, the lifetime of the inner disc (˜5 au; hereafter the MIR disc) is estimated to be ˜6.5 Myr, suggesting a very weak stellar mass dependence (M*). The much shorter K-disc lifetime compared to the MIR-disc lifetime for intermediate-mass (IM) stars suggests that IM stars with transition discs, which have only MIR excess emission but no K-band excess emission, are more common than classical Herbig Ae/Be stars, which exhibit both. We suggest that this prominent early disappearance of the K disc for IM stars is due to dust settling/growth in the protoplanetary disc, and it could be one of the major reasons for the paucity of close-in planets around IM stars.

Yasui, Chikako; Kobayashi, Naoto; Tokunaga, Alan T.; Saito, Masao

2014-08-01

346

Dependence of optic disc parameters on disc area according to Heidelberg Retina Tomograph: Part II.  

NASA Astrophysics Data System (ADS)

With the help of Heidelberg Retina Tomograph (HRT-II) optic disc parameters in 211 eyes of 115 healthy patients with refraction Em +/- 3,0 D and 96 eyes of 72 patients with myopia 3,5-14,0 D without any signs of glaucoma were studied. Analysis of optic disc parameters were carried out in 5 groups of patients according to disc area: less than 1,5 mm2, 1,5- 2,5 mm2, 2,5-3,0 mm2, 3,0-3,5 mm2 and more than 3,5 mm2. An accurate depending on disc area was revealed for all optic disc parameters in all sectors, which was manifested by increasing cup disc and rim disc (area and volume) and other parameters. We consider it is necessary to use the proper tables for right interpretation of received data for early diagnosis of glaucoma.

Machekhin, V.; Manaenkova, G.; Bondarenko, O.

2007-05-01

347

A 3-Arm, Randomized, Controlled Trial of Heat-Sensitive Moxibustion Therapy to Determine Superior Effect among Patients with Lumbar Disc Herniation  

PubMed Central

Systematic reviews of moxibustion for LDH have identified ponderable evidence, especially for heat-sensitive moxibustion (HSM). Therefore, we designed and carried out the large sample trial to evaluate it. 456 patients were recruited from 4 centers in China and were randomly divided into three groups by the ratio of 1?:?1?:?1 to HSM (152) group, conventional moxibustion (152) group, and conventional drug plus acupuncture (152) group. Compared with usual care, there was a statistically significant reduction in mean M-JOA score at 2 weeks and 6 months for HSM (3.8 ± 2.6 versus 8.5 ± 2.9; 3.7 ± 2.2 versus 10.1 ± 2.9) and conventional moxibustion (7.9 ± 3.0 versus 8.5 ± 2.9; 8.9 ± 3.1 versus 10.1 ± 2.9). Compared with conventional moxibustion group, HSM group showed greater improvement in all the outcomes. The mean dose of moxibustion was 41.13 ± 5.26 (range 21–60) minutes in the HSM group. We found that HSM was more effective in treating patients with LDH, compared with conventional moxibustion and conventional drug plus acupuncture. This finding indicated that the application of moxibustion on the heat-sensitive points is a good moxibustion technique in treating disease. PMID:25152757

Chen, Rixin; Chen, Mingren; Su, Tongsheng; Zhou, Meiqi; Sun, Jianhua; Xiong, Jun; Chi, Zhenhai; Xie, Dingyi; Zhang, Bo

2014-01-01

348

Hydrodynamics of the Vacuum  

E-print Network

Hydrodynamics is the appropriate "effective theory" for describing any fluid medium at sufficiently long length scales. This paper treats the vacuum as such a medium and derives the corresponding hydrodynamic equations. Unlike a normal medium the vacuum has no linear sound-wave regime; disturbances always "propagate" nonlinearly. For an "empty vacuum" the hydrodynamic equations are familiar ones (shallow water-wave equations) and they describe an experimentally observed phenomenon -- the spreading of a clump of zero-temperature atoms into empty space. The "Higgs vacuum" case is much stranger; pressure and energy density, and hence time and space, exchange roles. The speed of sound is formally infinite, rather than zero as in the empty vacuum. Higher-derivative corrections to the vacuum hydrodynamic equations are also considered. In the empty-vacuum case the corrections are of quantum origin and the post-hydrodynamic description corresponds to the Gross-Pitaevskii equation. I conjecture the form of the post-hydrodynamic corrections in the Higgs case. In the 1+1-dimensional case the equations possess remarkable `soliton' solutions and appear to constitute a new exactly integrable system.

P. M. Stevenson

2005-07-30

349

Evading death by vacuum  

E-print Network

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.

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

2013-03-15

350

Thermophoretic vacuum wand  

DOEpatents

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.

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

2000-01-01

351

Thermophoretic vacuum wand  

DOEpatents

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.

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

2001-01-01

352

On Entanglement with Vacuum  

E-print Network

The so-called entanglement with vacuum is not a property of the Fock space, but of some rather pathological representations of CCR/CAR algebras. In some other Fock space representations the notion simply does not exist. We have checked all the main Gedanken experiments where the notion of entanglement with vacuum was used, and found that all the calculations could be performed at a representation-independent level. In particular any such experiment can be formulated in a Fock-space representation where the notion of entanglement with vacuum is meaningless. So, for the moment there is no single experiment where the notion is needed, and probably it is simply unphysical.

Marcin Pawlowski; Marek Czachor

2005-07-16

353

Collapse of vacuum bubbles in a vacuum  

SciTech Connect

We revisit the dynamics of a false vacuum bubble in a background de Sitter spacetime. We find that there exists a large parameter space that allows the bubble to collapse into a black hole or to form a wormhole. This may have interesting implications for the creation of a baby universe in the laboratory, the string landscape where the bubble nucleation takes place among a plenitude of metastable vacua, and the inflationary physics.

Ng, Kin-Wang; Wang, Shang-Yung [Institute of Physics, Academia Sinica, Taipei, Taiwan 11529 (China); Department of Physics, Tamkang University, Tamsui, Taiwan 25137 (China)

2011-02-15

354

Vacuum Camera Cooler  

NASA Technical Reports Server (NTRS)

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.

Laugen, Geoffrey A.

2011-01-01

355

Cosmology of gravitational vacuum  

E-print Network

Production of gravitational vacuum defects and their contribution to the energy density of our Universe are discussed. These topological microstructures (defects) could be produced in the result of creation of the Universe from "nothing" when a gravitational vacuum condensate has appeared. They must be isotropically distributed over the isotropic expanding Universe. After Universe inflation these microdefects are smoothed, stretched and broken up. A part of them could survive and now they are perceived as the structures of Lambda-term and an unclustered dark matter. It is shown that the parametrization noninvariance of the Wheeler-De Witt equation can be used to describe phenomenologically vacuum topological defects of different dimensions (worm-holes, micromembranes, microstrings and monopoles). The mathematical illustration of these processes may be the spontaneous breaking of the local Lorentz-invariance of the quasi-classical equations of gravity. Probably the gravitational vacuum condensate has fixed tim...

Burdyuzha, V; Pacheco, J

2008-01-01

356

Cosmology of gravitational vacuum  

E-print Network

Production of gravitational vacuum defects and their contribution to the energy density of our Universe are discussed. These topological microstructures (defects) could be produced in the result of creation of the Universe from "nothing" when a gravitational vacuum condensate has appeared. They must be isotropically distributed over the isotropic expanding Universe. After Universe inflation these microdefects are smoothed, stretched and broken up. A part of them could survive and now they are perceived as the structures of Lambda-term and an unclustered dark matter. It is shown that the parametrization noninvariance of the Wheeler-De Witt equation can be used to describe phenomenologically vacuum topological defects of different dimensions (worm-holes, micromembranes, microstrings and monopoles). The mathematical illustration of these processes may be the spontaneous breaking of the local Lorentz-invariance of the quasi-classical equations of gravity. Probably the gravitational vacuum condensate has fixed time in our Universe. Besides, 3-dimensional topological defects renormalize Lambda-term.

V. Burdyuzha; G. Vereshkov; J. Pacheco

2007-12-29

357

Pumpdown and Vacuum Pumps  

NSDL National Science Digital Library

This is a link to a PDF version of lecture slides that discuss vacuum pumpdown. Graphics are included which depict pumpdown procedure, venting procedure, pressure curves and system pumpdown. Keywords: Outgassing, pressure range, rotary vane, rotary piston, roots blower

Rack, Philip D.

358

Ferromagnetic Ni(II) discs.  

PubMed

A family of planar disc-like hexa-, octa- and decametallic Ni(II) complexes exhibit dominant ferromagnetic exchange. The deca- and octametallic clusters [Ni(II) (10)(tmp)(2)(N(3))(8)(acac)(6)(MeOH)(6)] (1, H(3)tmp=1,1,1-tris(hydroxymethyl)propane; acac=acetylacetonate) and [Ni(II) (8)(thme)(2)(O(2)CPh)(4)(Cl)(6)(MeCN)(6)(H(2)O)(2)] (2, H(3)thme=1,1,1-tris(hydroxymethyl)ethane) represent rare examples of Ni(II)-based single-molecule magnets, and [Ni(II) (10)] (1) possesses the largest barrier to magnetisation reversal of any Ni(II) single-molecule magnet to date. PMID:19757431

Scott, Richard T W; Jones, Leigh F; Tidmarsh, Ian S; Breeze, Barbara; Laye, Rebecca H; Wolowska, Joanna; Stone, Daniel J; Collins, Anna; Parsons, Simon; Wernsdorfer, Wolfgang; Aromí, Guillem; McInnes, Eric J L; Brechin, Euan K

2009-11-16

359

Autologous adipose stem cells and polylactide discs in the replacement of the rabbit temporomandibular joint disc  

PubMed Central

The temporomandibular joint (TMJ) disc lacks functional replacement after discectomy. We investigated tissue-engineered bilayer polylactide (PLA) discs and autologous adipose stem cells (ASCs) as a potential replacement for the TMJ disc. These ASC discs were pre-cultured either in control or in differentiation medium, including transforming growth factor (TGF)-?1 for one week. Prior to implantation, expression of fibrocartilaginous genes was measured by qRT-PCR. The control and differentiated ASC discs were implanted, respectively, in the right and left TMJs of rabbits for six (n = 5) and 12 months (n = 5). Thereafter, the excised TMJ areas were examined with cone beam computed tomography (CBCT) and histology. No signs of infection, inflammation or foreign body reactions were detected at histology, whereas chronic arthrosis and considerable condylar hypertrophy were observed in all operated joints at CBCT. The left condyle treated with the differentiated ASC discs appeared consistently smoother and more sclerotic than the right condyle. The ASC disc replacement resulted in dislocation and morphological changes in the rabbit TMJ. The ASC discs pre-treated with TGF-?1 enhanced the condylar integrity. While adverse tissue reactions were not shown, the authors suggest that with improved attachment and design, the PLA disc and biomaterial itself would hold potential for TMJ disc replacement. PMID:23720535

Ahtiainen, Katja; Mauno, Jari; Ellä, Ville; Hagström, Jaana; Lindqvist, Christian; Miettinen, Susanna; Ylikomi, Timo; Kellomäki, Minna; Seppänen, Riitta

2013-01-01

360

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

E-print Network

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 ${M}_{\\rm disc}-M_*$ relation (which is derived for stars with masses $M_*>0.2 {\\rm M}_{\\odot}$). Accordingly, the accretion rates onto 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 onto it. The discs around objects that form by disc fragmentation have larger than expected m...

Stamatellos, Dimitris

2015-01-01

361

Episodic accretion in magnetically layered protoplanetary discs  

E-print Network

We study protoplanetary disc evolution assuming that angular momentum transport is driven by gravitational instability at large radii, and magnetohydrodynamic (MHD) turbulence in the hot inner regions. At radii of the order of 1 AU such discs develop a magnetically layered structure, with accretion occurring in an ionized surface layer overlying quiescent gas that is too cool to sustain MHD turbulence. We show that layered discs are subject to a limit cycle instability, in which accretion onto the protostar occurs in bursts with an accretion rate of 10^{-5} solar masses / yr, separated by quiescent intervals where the accretion rate is 10^{-8} solar masses / yr. Such bursts could lead to repeated episodes of strong mass outflow in Young Stellar Objects. The transition to this episodic mode of accretion occurs at an early epoch (t < 1 Myr), and the model therefore predicts that many young pre-main-sequence stars should have low rates of accretion through the inner disc. At ages of a few Myr, the discs are up to an order of magnitude more massive than the minimum mass solar nebula, with most of the mass locked up in the quiescent layer of the disc at around 1 AU. The predicted rate of low mass planetary migration is reduced at the outer edge of the layered disc, which could lead to an enhanced probability of giant planet formation at radii of 1-3 AU.

Philip J. Armitage; Mario Livio; J. E. Pringle

2001-01-16

362

Spectroscopic Parameters of Lumbar Intervertebral Disc Material  

NASA Astrophysics Data System (ADS)

There are numerous methods of investigating intervertebral disc. Visualization methods are widely used in clinical practice. Histological, imunohistochemical and biochemical methods are more used in scientific research. We propose that a new spectroscopic investigation would be useful in determining intervertebral disc material, especially when no histological specimens are available. Purpose: to determine spectroscopic parameters of intervertebral disc material; to determine emission spectra common for all intervertebral discs; to create a background for further spectroscopic investigation where no histological specimen will be available. Material and Methods: 20 patients, 68 frozen sections of 20 ?m thickness from operatively removed intervertebral disc hernia were excited by Nd:YAG microlaser STA-01-TH third harmonic 355 nm light throw 0, 1 mm fiber. Spectrophotometer OceanOptics USB2000 was used for spectra collection. Mathematical analysis of spectra was performed by ORIGIN multiple Gaussian peaks analysis. Results: In each specimen of disc hernia were found distinct maximal spectral peaks of 4 types supporting the histological evaluation of mixture content of the hernia. Fluorescence in the spectral regions 370-700 nm was detected in the disc hernias. The main spectral component was at 494 nm and the contribution of the components with the peak wavelength values at 388 nm, 412 nm and 435±5 nm were varying in the different groups of samples. In comparison to average spectrum of all cases, there are 4 groups of different spectral signatures in the region 400-500 nm in the patient groups, supporting a clinical data on different clinical features of the patients. Discussion and Conclusion: besides the classical open discectomy, new minimally invasive techniques of treating intervertebral disc emerge (PLDD). Intervertebral disc in these techniques is assessed by needle, no histological specimen is taken. Spectroscopic investigation via fiber optics through the needle can give additional information of needle position, assuring the needle tip is directed into intervertebral disc material. Spectroscopic analysis of intervertebral disc removed during open surgery, creates background for further investigation on intervertebral disc degeneration spectral classification.

Terbetas, G.; Kozlovskaja, A.; Varanius, D.; Graziene, V.; Vaitkus, J.; Vaitkuviene, A.

2009-06-01

363

DISC1 genetics, biology and psychiatric illness  

PubMed Central

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

THOMSON, Pippa A.; MALAVASI, Elise L.V.; GRÜNEWALD, Ellen; SOARES, Dinesh C.; BORKOWSKA, Malgorzata; MILLAR, J. Kirsty

2012-01-01

364

VACUUM SYSTEMS PHYSICS 359E  

E-print Network

VACUUM SYSTEMS PHYSICS 359E September 28, 2004 INTRODUCTION In this laboratory, you will familiarize yourself with the principles of simple vacuum systems and their use. You will measure the pumping.) VACUUM SYSTEMS AND COMPONENTS In one way or another vacuum techniques appear in most fields of modern

Landstreet, John D.

365

Laser photoacoustic detection of CO2 in old disc tree-rings.  

PubMed

A homemade CO2-laser photoacoustic spectrometer has been used for monitoring CO2 in gas samples extracted under vacuum from the wood of old spruce disc tree-rings for a ?60 year series. The experimental results show that (1) the CO2 concentration exhibits annual trends correlated with an increase in atmospheric CO2 in a number of cases; (2) at the time when the annual CO2 trend changes from positive to negative, the annual tree-ring stable carbon isotope ratios (?13C) of CO2 change as well; (3) the disc tree-ring widths are observed to decrease in most cases where the annual CO2 increased; (4) simultaneously with the annual CO2 variation, annual H2O distribution was detected in gas samples of the wood tree-rings of one spruce disc. The observed patterns of the annual CO2 distribution in the disc tree-rings are assumed to be the evidence of the impact of the atmospheric CO2 increase. In other words, a change in the concentration gradient between the stem and the atmospheric CO2 may lead to a gradual CO2 accumulation in the stem because of a decrease in the diffusion rate and to a change in the tree parameters. PMID:22319299

Ageev, Boris; Ponomarev, Yurii; Sapozhnikova, Valeria

2010-01-01

366

Optical effects related to Keplerian discs orbiting Kehagias-Sfetsos naked singularities  

NASA Astrophysics Data System (ADS)

We demonstrate possible optical signatures of the Kehagias-Sfetsos (KS) naked singularity spacetimes representing a spherically symmetric vacuum solution of the modified Ho?ava gravity. In such spacetimes, accretion structures significantly different from those present in standard black hole spacetimes occur due to the ‘antigravity’ effect, which causes an internal static sphere surrounded by Keplerian discs. We focus our attention on the optical effects related to the Keplerian accretion discs, constructing the optical appearance of the Keplerian discs, the spectral continuum due to their thermal radiation, and the spectral profiled lines generated in the innermost parts of such discs. The KS naked singularity signature is strongly encoded in the characteristics of predicted optical effects, especially in cases where the spectral continuum and spectral lines are profiled by the strong gravity of the spacetimes due to the vanishing region of the angular velocity gradient influencing the effectiveness of the viscosity mechanism. We can conclude that optical signatures of KS naked singularities can be well distinguished from the signatures of standard black holes.

Stuchlík, Zden?k; Schee, Jan

2014-10-01

367

Mechanical differences between lumbar and tail discs in the mouse  

Microsoft Academic Search

The mouse lumbar and tail discs are both used as models to study disc degeneration; however, the mechanical behavior of these two levels has not been compared. The objective of this study was to compare the elastic and viscoelastic mechanical properties of lumbar and tail discs of the mouse under axial compression–tension loading. We hypothesized that tail discs would have

Joseph J. Sarver; Dawn M. Elliott

2005-01-01

368

21 CFR 866.1620 - Antimicrobial susceptibility test disc.  

Code of Federal Regulations, 2013 CFR

...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...

2013-04-01

369

Total disc replacement surgery for symptomatic degenerative lumbar disc disease: a systematic review of the literature  

Microsoft Academic Search

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

Karin D. van den Eerenbeemt; Raymond W. Ostelo; Barend J. van Royen; Wilco C. Peul; Maurits W. van Tulder

2010-01-01

370

Evolution from protoplanetary to debris discs: the transition disc around HD 166191  

NASA Astrophysics Data System (ADS)

HD 166191 has been identified by several studies as hosting a rare and extremely bright warm debris disc with an additional outer cool disc component. However, an alternative interpretation is that the star hosts a disc that is currently in transition between a full gas disc and a largely gas-free debris disc. With the help of new optical to mid-infrared (IR) spectra and Herschel imaging, we argue that the latter interpretation is supported in several ways: (i) we show that HD 166191 is comoving with the ˜4-Myr-old Herbig Ae star HD 163296, suggesting that the two have the same age; (ii) the disc spectrum of HD 166191 is well matched by a standard radiative transfer model of a gaseous protoplanetary disc with an inner hole and (iii) the HD 166191 mid-IR silicate feature is more consistent with similarly primordial objects. We note some potential issues with the debris disc interpretation that should be considered for such extreme objects, whose lifetime at the current brightness is much shorter than the stellar age, or in the case of the outer component requires a mass comparable to the solid component of the solar nebula. These aspects individually and collectively argue that HD 166191 is a 4-5 Myr old star that hosts a gaseous transition disc. Though it does not argue in favour of either scenario, we find strong evidence for 3-5 ?m disc variability. We place HD 166191 in context with discs at different evolutionary stages, showing that it is a potentially important object for understanding the protoplanetary to debris disc transition.

Kennedy, G. M.; Murphy, S. J.; Lisse, C. M.; Ménard, F.; Sitko, M. L.; Wyatt, M. C.; Bayliss, D. D. R.; DeMeo, F. E.; Crawford, K. B.; Kim, D. L.; Rudy, R. J.; Russell, R. W.; Sibthorpe, B.; Skinner, M. A.; Zhou, G.

2014-03-01

371

Spinal cord herniation as a complication of en bloc, multilevel, anterior thoracic vertebrectomy for a giant cell tumor: success of posterior cord reduction and dural repair.  

PubMed

Iatrogenic spinal cord herniation is a rare complication following spinal stabilization surgery. The authors present a case of circumferential thoracic tumor decompression and fixation by anterior instrumentation complicated by delayed anterior spinal cord herniation. This complication resulted in progressive paraparesis 5 years after the original procedure. The patient underwent reexploration and repair of the dural defect, resulting in the reduction of the spinal cord to its normal position. The patient's paraparesis improved significantly after dural repair. Although progression of neurological deficit can be very slow, repair of the dural defect can restore normal spinal cord alignment and improve neurological deficit. To the best of the authors' knowledge, this is the first reported case of spinal cord herniation following an anterior thoracic vertebrectomy. PMID:25237844

Kawsar, Khandkar A; Bhatia, Robin; Casey, Adrian C T H

2014-12-01

372

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.

373

Planet formation in self-gravitating discs   

E-print Network

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 ...

Gibbons, Peter George

2013-11-28

374

Evolution of solids in protoplanetary discs  

NASA Astrophysics Data System (ADS)

1d code designed to track the evolution of solids in protoplanetary discs from an early stage, when all solids are in the dust form, to the stage when most solids are in the form of a planetesimal swarm.

Kornet, K.

2006-10-01

375

Mapping applications of video disc technology  

NASA Astrophysics Data System (ADS)

Video discs can store large quantities of analog map products in a compact, nonvolatile format. Interfacing them to microcomputers provides a portable, rugged means of accessing cartographic information. This new technology has many potential applications in map data storage, navigation, training, and decision making. The U.S. Army Engineer Topographic Laboratories (USAETL) is studying hardware, software, and map design aspects of video discs with a prototype Map Video Processing (MVP) system.

Costanzo, D. J.

1983-06-01

376

Investigation of cryogenic rupture disc design  

NASA Technical Reports Server (NTRS)

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.

Keough, J. B.; Oldland, A. H.

1973-01-01

377

Footprint mismatch in lumbar total disc arthroplasty  

Microsoft Academic Search

Lumbar disc arthroplasty has become a popular modality for the treatment of degenerative disc disease. The dimensions of the\\u000a implants are based on early published geometrical measurements of vertebrae; the majority of these were cadaver studies. The\\u000a fit of the prosthesis in the intervertebral space is of utmost importance. An undersized implant may lead to subsidence, loosening\\u000a and biomechanical failure

Gstoettner Michaela; Heider Denise; Michael Liebensteiner; Bach Christian Michael

2008-01-01

378

Disc valve for sampling erosive process streams  

DOEpatents

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.

Mrochek, John E. (Oak Ridge, TN); Dinsmore, Stanley R. (Norris, TN); Chandler, Edward W. (Knoxville, TN)

1986-01-01

379

Design concepts in lumbar total disc arthroplasty  

Microsoft Academic Search

The implantation of lumbar disc prostheses based on different design concepts is widely accepted. This paper reviews currently\\u000a available literature studies on the biomechanics of TDA in the lumbar spine, and is targeted at the evaluation of possible\\u000a relationships between the aims of TDA and the geometrical, mechanical and material properties of the various available disc\\u000a prostheses. Both theoretical and

Fabio Galbusera; Chiara M. Bellini; Thomas Zweig; Stephen Ferguson; Manuela T. Raimondi; Claudio Lamartina; Marco Brayda-Bruno; Maurizio Fornari

2008-01-01

380

Stellar wind erosion of protoplanetary discs  

NASA Astrophysics Data System (ADS)

An analytic model is developed for the erosion of protoplanetary gas discs by high-velocity magnetized stellar winds. The winds are centrifugally driven from the surface of rapidly rotating, strongly magnetized young stars. The presence of the magnetic field in the wind leads to Reynolds numbers sufficiently large to cause a strongly turbulent wind/disc boundary layer which entrains and carries away the disc gas. The model uses the conservation of mass and momentum in the turbulent boundary layer. The time-scale for significant erosion depends on the disc accretion speed, disc accretion rate, the wind mass-loss rate, and the wind velocity. The time-scale is estimated to be ˜2 × 106 yr. The analytic model assumes a steady stellar wind with mass- loss rate dot {M}}_w ˜ 10^{-10} M_{?} yr-1 and velocity vw ˜ 103 km s-1. A significant contribution to the disc erosion can come from frequent powerful coronal mass ejections (CMEs) where the average mass-loss rate in CMEs, dot{M}_CME, and velocities, vCME, have values comparable to those for the steady wind.

Schnepf, N. R.; Lovelace, R. V. E.; Romanova, M. M.; Airapetian, V. S.

2015-04-01

381

Proteomic Signature of the Murine Intervertebral Disc  

PubMed Central

Low back pain is the most common musculoskeletal problem and the single most common cause of disability, often attributed to degeneration of the intervertebral disc. Lack of effective treatment is directly related to our limited understanding of the pathways responsible for maintaining disc health. While transcriptional analysis has permitted initial insights into the biology of the intervertebral disc, complete proteomic characterization is required. We therefore employed liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) protein/peptide separation and mass spectrometric analyses to characterize the protein content of intervertebral discs from skeletally mature wild-type mice. A total of 1360 proteins were identified and categorized using PANTHER. Identified proteins were primarily intracellular/plasma membrane (35%), organelle (30%), macromolecular complex (10%), extracellular region (9%). Molecular function categorization resulted in three distinct categories: catalytic activity (33%), binding (molecule interactions) (29%), and structural activity (13%). To validate our list, we confirmed the presence of 14 of 20 previously identified IVD-associated markers, including matrix proteins, transcriptional regulators, and secreted proteins. Immunohistochemical analysis confirmed distinct localization patterns of select protein with the intervertebral disc. Characterization of the protein composition of healthy intervertebral disc tissue is an important first step in identifying cellular processes and pathways disrupted during aging or disease progression. PMID:25689066

McCann, Matthew R.; Patel, Priya; Frimpong, Agya; Xiao, Yizhi; Siqueira, Walter L.; Séguin, Cheryle A.

2015-01-01

382

Steroid treatment can inhibit nuclear localization of members of the NF-?B pathway in human disc cells stimulated with TNF-?  

PubMed

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

Quan, Meiling; Park, Sang-Eun; Lin, Zhenhua; Hong, Myung-Wha; Park, Seong-Yel; Kim, Young-Yul

2014-07-19

383

Vacuum driven accelerated expansion  

E-print Network

It has been shown that an improved estimation of quantum vacuum energy can yield not only acceptable but also experimentally sensible results. The very idea consists in a straightforward extraction of gravitationally interacting part of the full quantum vacuum energy by means of gauge transformations. The implementation of the idea has been performed in the formalism of effective action, in the language of Schwinger's proper time and the Seeley-DeWitt heat kernel expansion, in the background of the Friedmann-Robertson-Walker geometry.

Bogus?aw Broda; Piotr Bronowski; Marcin Ostrowski; Micha? Szanecki

2008-12-29

384

Electrostatic Levitator Vacuum Chamber  

NASA Technical Reports Server (NTRS)

Optical ports ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (beam passes through the window at left), positioning lasers (one port is at center), and lamps to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

1998-01-01

385

Stellar irradiated discs and implications on migration of embedded planets. I. Equilibrium discs  

NASA Astrophysics Data System (ADS)

Context. The strength and direction of migration of embedded low mass planets depends on the disc's thermodynamic state. It has been shown that, in discs where the viscous heating is balanced by radiative transport, the migration can be directed outwards, a process which extends the lifetime of growing planetary embryos. Aims: We investigate the influence of opacity and stellar irradiation on the disc thermodynamics. We focus on equilibrium discs, which have no net mass flux. Utilizing the resulting disc structure, we determine the regions of outward migration in the disc. Methods: We performed two-dimensional numerical simulations of equilibrium discs with viscous heating, radiative cooling, and stellar irradiation. We used the explicit/implicit hydrodynamical code NIRVANA that includes a full tensor viscosity and stellar irradiation, as well as a two temperature solver that includes radiation transport in the flux-limited diffusion approximation. The migration of embedded planets was studied by using torque formulae. Results: In the constant opacity case, our code reproduces the analytical results corresponding to a black-body disc: the stellar irradiation dominates in the outer regions - leading to flaring (H/r ? r2/7) - while the viscous heating dominates close to the star. In particular, we find that the inner edge of the disc should not be significantly puffed-up by the stellar irradiation. If the opacity depends on the local density and temperature, the structure of the disc is different, and several bumps in the aspect ratio H/r appear, due to transitions between different opacity regimes. The bumps in the disc structure are very important, as they can shield the outer disc from stellar irradiation. Conclusions: Stellar irradiation is an important factor for determining the disc structure and has dramatic consequences for the migration of embedded planets. Compared to discs with only viscous heating and radiative cooling, a stellar irradiated disc features a much smaller region of outward migration for a range of planetary masses. This suggests that the region where the formation of giant planet cores takes place is smaller, which in turn might lead to a shorter growth phase.

Bitsch, B.; Crida, A.; Morbidelli, A.; Kley, W.; Dobbs-Dixon, I.

2013-01-01

386

Liquid Immersion Deep-UV Optical Disc Mastering for Blu-ray Disc Read-Only Memory  

Microsoft Academic Search

The liquid immersion mastering technique has been successfully applied to the mastering of read-only memory (ROM) discs for the Blu-ray disc (BD) system. Replicated discs with a density corresponding to 25 GB in a single layer on a 12 cm disc showed a bottom jitter of less than 5%. Results concerning process latitude and disc uniformity are presented. A full-format

Jaap H. M. Neijzen; Erwin R. Meinders; Helmar van Santen

2004-01-01

387

Langmuir vacuum and superconductivity  

SciTech Connect

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.

Veklenko, B. A. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2012-06-15

388

The vacuum conservation theorem  

NASA Astrophysics Data System (ADS)

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.

Minguzzi, E.

2015-03-01

389

Vacuum System at IUAC  

NASA Astrophysics Data System (ADS)

Vacuum technology is an integral part of any accelerator system. At IUAC we have a 15UD PELLETRON, superconduting LINAC, Low Energy Ion beam Facility and a 1.7MV pelletron. Vacuum requirement in these accelerators is ~10-8 torr. Various types of Vacuum pump are used in different zones of the accelerators depending on load. Since the whole accelerator is quite long, distributed pumps are placed in different sections as per load. In ion sources displacement type pump viz turbo-pumps are usually used as the gas load is quite high. In other parts of the accelerator combination of getter and ion pumps are used. It is very much necessary to isolate different sections for maintenance purpose. Proper valves are used to isolate the sections and to avoid vacuum accidents proper interlock system is introduced. If air goes in some sections accidentally, valves will close automatically to protect other sections. The talk will cover different types of pumps and interlock used in accelerators at IUAC.

Mandal, A.

2012-11-01

390

Triggered vacuum gaps  

Microsoft Academic Search

Characteristics of a sealed vacuum gap are described and the difficulties encountered in applying this gap as an overvoltage protection device are discussed. It is shown how these difficulties can be ameliorated by the use of gas-free electrode materials and by triggering the gap when breakdown is required. Several methods of triggering are discussed and some practical triggering devices are

J. M. Lafferty

1966-01-01

391

Vacuum configurations for superstrings  

Microsoft Academic Search

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

P. Candelas; Gary T. Horowitz; Andrew Strominger; Edward Witten

1985-01-01

392

Type D Vacuum Metrics  

Microsoft Academic Search

Using the Newman-Penrose formalism, the vacuum field equations are solved for Petrov type D. An exhaustive set of ten metrics is obtained, including among them a new rotating solution closely related to the Ehlers-Kundt ``C'' metric. They all possess at least two Killing vectors and depend only on a small number of arbitrary constants.

William Kinnersley

1969-01-01

393

Vacuum arc recovery phenomena  

Microsoft Academic Search

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

J. A. Rich; G. A. Farrall

1964-01-01

394

Vacuum Kundt waves  

NASA Astrophysics Data System (ADS)

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.

McNutt, David; Milson, Robert; Coley, Alan

2013-03-01

395

(Reverse) engineering vacuum alignment  

Microsoft Academic Search

In the presence of spontaneous symmetry breaking, the alignment of the vacuum with respect to the gauge group is often controlled by quadratically divergent operators in the low energy non-linear sigma model. In principle the magnitudes and signs of these operators can be changed by making different assumptions about the ultraviolet physics, but in practice all known ways of regulating

Clifford Cheung; Jesse Thaler

2006-01-01

396

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...

397

Liquid immersion deep-UV optical disc mastering for high data capacity ROM discs  

NASA Astrophysics Data System (ADS)

In this paper we describe the liquid immersion mastering technique and its application to the mastering of ROM discs for the Blu-ray Disc system and for ROM discs with considerably higher data densities. Replicated 25GB BD-ROM discs were evaluated using a standard blue test player (?=405nm, NA=0.85). A bottom jitter value with limit equalizer of less than 5% was measured. Also the values of asymmetry, normalized push pull and symbol error rate were well within the Blu-ray Disc format specification, offering a large process window. Full-format BD-ROM test discs with high definition video content were mastered and their successful read-back was demonstrated. In addition we show that liquid immersion mastering can successfully be applied for mastering of considerably higher densities. Measurements on replicated discs up to data densities above 40GB per layer are discussed. The present results demonstrate that liquid immersion mastering is a proven technology for the mass-production of high data capacity ROM discs.

Neijzen, Jaap H. M.; Meinders, Erwin R.; Boamfa, Marius I.; Chen, Dianyong

2005-09-01

398

Expression of DISC1 binding partners is reduced in schizophrenia and associated with DISC1 SNPs  

E-print Network

. INTRODUCTION Schizophrenia is a psychiatric disorder characterized by cognitive impairment, disturbances for polygenic disorders like schizophrenia will likely require demonstration that genetic variation predictsExpression of DISC1 binding partners is reduced in schizophrenia and associated with DISC1 SNPs

Baker, Chris I.

399

Blu-ray Disc\\/Digital Versatile Disc Recording and Reproducing Compatible Use Technology in the 2nd Generation Pick Up for Blu-ray Disc  

Microsoft Academic Search

We developed a 2nd generation pick up for the Blu-ray disc (BD), which makes possible recording and reproducing on both BD and digital versatile disc (DVD), and has a size for audio and visual (AV) and personal computer (PC) applications. These properties are realized by a single objective lens and a newly developed hologram element. The next generation optical disc

Ichiro Morishita; Hiroyuki Shindo; Noriyoshi Takeya; Hoseop Jeong; Yonghan Yoon; Incheol Chang; Hyungjin Kim; Dongwoo Lee; Chonsu Kyong

2004-01-01

400

Angular Momentum Transfer in Star-Discs Encounters: The Case of Low-Mass Discs  

E-print Network

A prerequisite for the formation of stars and planetary systems is that angular momentum is transported in some way from the inner regions of the accretion disc. Tidal effects may play an important part in this angular momentum transport. Here the angular momentum transfer in an star-disc encounter is investigated numerically for a variety of encounter parameters in the case of low mass discs. Although good agreement is found with analytical results for the entire disc, the loss {\\it inside} the disc can be up to an order of magnitude higher than previously assumed. The differences in angular momentum transport by secondaries on a hyperbolic, parabolic and elliptical path are shown, and it is found that a succession of distant encounters might be equally, if not more, successful in removing angular momentum than single close encounter.

S. Pfalzner

2003-10-27

401

Demonstrations with a Vacuum: Old Demonstrations for New Vacuum Pumps.  

ERIC Educational Resources Information Center

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…

Greenslade, Thomas B., Jr.

1989-01-01

402

Dynamo Action in Turbulent Accretion Discs around Black Holes - Part Two - the Mean Magnetic Field  

NASA Astrophysics Data System (ADS)

The presence of strong differential rotation and vertical density gradients in thin accretion discs allows the generation of a large-scale, mean magnetic field by ?? dynamo action. Analytic expressions for the preferred steady-state solutions are found, which when matched on to an exterior vacuum field show that the class of quadrupole modes (B? and Br even, and Bz odd functions of z) are most easily excited. The critical dynamo number of this mode is |Q*e,c1/3 = 2.4, corresponding to a turbulent Mach number of Met = 0.19.

Pudritz, R. E.

1981-06-01

403

Tritium handling in vacuum systems  

SciTech Connect

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.

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

404

Dielectric Theory of the Vacuum  

E-print Network

The vacuum is proposed to be a dielectric medium constituted of neutral but polarizable vacuuons based on overall experimental observations in separate publications. In the present paper I formally develop the dielectric theory for this dielectric vacuum.

J. X. Zheng-Johansson

2006-12-11

405

Footprint mismatch in lumbar total disc arthroplasty  

PubMed Central

Lumbar disc arthroplasty has become a popular modality for the treatment of degenerative disc disease. The dimensions of the implants are based on early published geometrical measurements of vertebrae; the majority of these were cadaver studies. The fit of the prosthesis in the intervertebral space is of utmost importance. An undersized implant may lead to subsidence, loosening and biomechanical failure due to an incorrect center of rotation. The aim of the present study was to measure the dimensions of lumbar vertebrae based on CT scans and assess the accuracy of match in currently available lumbar disc prostheses. A total of 240 endplates of 120 vertebrae were included in the study. The sagittal and mediolateral diameter of the upper and lower endplates were measured using a digital measuring system. For the levels L4/L5 and L5/S1, an inappropriate size match was noted in 98.8% (Prodisc L) and 97.6% (Charite) with regard to the anteroposterior diameter. Mismatch in the anterior mediolateral diameter was noted in 79.3% (Prodisc L) and 51.2% (Charite) while mismatch in the posterior mediolateral diameter was observed in 91.5% (Prodisc L) and 78% (Charite) of the endplates. Surgeons and manufacturers should be aware of the size mismatch of currently available lumbar disc prostheses, which may endanger the safety and efficacy of the procedure. Larger footprints of currently available total disc arthroplasties are required. PMID:18791748

Michaela, Gstoettner; Denise, Heider; Liebensteiner, Michael

2008-01-01

406

A radiation hard vacuum switch  

DOEpatents

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.

Boettcher, G.E.

1988-07-19

407

Portable vacuum object handling device  

DOEpatents

The disclosure relates to a portable device adapted to handle objects which are not to be touched by hand. A piston and bore wall form a vacuum chamber communicating with an adaptor sealably engageable with an object to be lifted. The piston is manually moved and set to establish vacuum. A valve is manually actuatable to apply the vacuum to lift the object.

Anderson, Gordon H. (Los Alamos, NM)

1983-08-09

408

Vacuum Energy:. Myths and Reality  

NASA Astrophysics Data System (ADS)

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.

Volovik, G. E.

409

Vacuum Energy: Myths and Reality  

E-print Network

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.

G. E. Volovik

2006-07-10

410

Vacuum Electronics: Status and Trends  

Microsoft Academic Search

The vast preponderance of U.S. radar transmitters today use vacuum electronic amplifiers, spanning the spectrum from UHF to EHF. Enhancements to performance, reliability, and cost of ownership are being applied continuously to these systems; routine in-service life extensions mandate continuing vacuum electronics research and development to support system needs for the foreseeable future. In addition, exciting advances in vacuum electronics

Baruch Levush; D. K. Abe; J. P. Calame; B. G. Danly; K. T. Nguyen; E. J. Dutkowski; R. H. Abrams; R. K. Parker

2007-01-01

411

Vacuum Electronics: Status and Trends  

Microsoft Academic Search

The vast preponderance of US radar transmitters today use vacuum electronic amplifiers, spanning the spectrum from UHF to EHF. Enhancements to performance, reliability, and cost of ownership are being applied continuously to these systems: routine in-service life extensions mandate continuing vacuum electronics research and development to support system needs for the foreseeable future. In addition, exciting advances in vacuum electronics

Baruch Levush; David K. Abe; Jeffrey P. Calame; Bruce G. Danly; Khanh T. Nguyen; E. Joseph Dutkowski; R. H. Abrams; Robert Parker

2007-01-01

412

Influence of the temperature on the tribological behaviour of PEEK composites in vacuum environment  

NASA Astrophysics Data System (ADS)

This paper describes tribological experiments carried out with polyetheretherketone (PEEK), filled with carbon fibres and solid lubricants (polytetrafluoroethylene (PTFE), graphite or MoS2), against steel discs. Oscillating sliding tests were performed in high vacuum environment in the temperature range between -40°C and +160°C. Results indicate that MoS2 filled PEEK show the best tribological performance in vacuum. Particularly, in the lower temperature range and at higher loads the friction behaviour is improved by the MoS2 content.

Theiler, G.; Gradt, T.

2008-03-01

413

Vacuum tool manipulator  

DOEpatents

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.

Zollinger, William T. (3927 Almon Dr., Martinez, GA 30907)

1993-01-01

414

Edison's vacuum technology patents  

NASA Astrophysics Data System (ADS)

During 1879 Thomas Edison's Menlo Park, New Jersey laboratory developed the means to evacuate glass lamp globes to less than a mTorr in 20 min and in mid-1880 began production of carbon-filament incandescent lamps. Among Edison's nearly 1100 U.S. patents are five for vacuum pump improvements, and at least eight others that are vacuum-related; all applied for between 1880 and 1886. Inspired by an 1878 article by De La Rue and Müller [Philos. Trans. R. Soc. London, Ser. A 169, 155 (1878)] on studies of glow discharges, Edison devised a combination pump using the Geissler pump as a rough pump and the Sprengel pump for continuous exhaustion. Edison's patents described means to control the mercury flow and automate the delivery of the mercury to banks of up to a hundred pumps. Other patents described various means to remove residual gases during lamp processing.

Waits, Robert K.

2003-07-01

415

Rotating vacuum wormhole  

E-print Network

We investigate whether self-maintained vacuum traversible wormhole can exist described by stationary but nonstatic metric. We consider metric being the sum of static spherically symmetric one and a small nondiagonal component which describes rotation sufficiently slow to be taken into account in the linear approximation. We study semiclassical Einstein equations for this metric with vacuum expectation value of stress-energy of physical fields as the source. In suggestion that the static traversible wormhole solution exists we reveal possible azimuthal angle dependence of angular velocity of the rotation (angular velocity of the local inertial frame) that solves semiclassical Einstein equations. We find that in the macroscopic (in the Plank scale) wormhole case a rotational solution exists but only such that, first, angular velocity depends on radial coordinate only and, second, the wormhole connects the two asymptotically flat spacetimes rotating with angular velocities different in asymptotic regions.

V. M. Khatsymovsky

1998-03-06

416

Compact vacuum insulation embodiments  

DOEpatents

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.

Benson, D.K.; Potter, T.F.

1992-04-28

417

Compact vacuum insulation  

DOEpatents

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.

Benson, D.K.; Potter, T.F.

1993-01-05

418

Vacuum Structure and Potential  

E-print Network

Based on overall experimental observations, especially the pair processes, I developed a model structure of the vacuum along with a basic-particle formation scheme begun in 2000 (with collaborator P-I Johansson). The model consists in that the vacuum is, briefly, filled of neutral but polarizable vacuuons, consisting each of a p-vaculeon and n- vaculeon of charges $+e$ and $-e$ of zero rest masses but with spin motions, assumed interacting each other with a Coulomb force. The model has been introduced in full in a book (Nova Sci, 2005) and referred to in a number of journal/E-print papers. I outline in this easier accessible paper the detailed derivation of the model and a corresponding quantitative determination of the vacuuon size.

J. X. Zheng-Johansson

2007-04-02

419

Vacuum tool manipulator  

DOEpatents

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.

Zollinger, W.T.

1993-11-23

420

Dry vacuum pumps  

NASA Astrophysics Data System (ADS)

For decades and for ultimate pressure below 1 mbar, oil-sealed Rotary Vane Pumps have been the most popular solution for a wide range of vacuum applications. In the late 80ies, Semiconductor Industry has initiated the development of the first dry roughing pumps. Today SC applications are only using dry pumps and dry pumping packages. Since that time, pumps manufacturers have developed dry vacuum pumps technologies in order to make them attractive for other applications. The trend to replace lubricated pumps by dry pumps is now spreading over many other market segments. For the Semiconductor Industry, it has been quite easy to understand the benefits of dry pumps, in terms of Cost of Ownership, process contamination and up-time. In this paper, Technology of Dry pumps, its application in R&D/industries, merits over conventional pumps and future growth scope will be discussed.

Sibuet, R.

2008-05-01

421

Compact vacuum insulation embodiments  

DOEpatents

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.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1992-01-01

422

Compact vacuum insulation  

DOEpatents

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.

Benson, David K. (Golden, CO); Potter, Thomas F. (Denver, CO)

1993-01-01

423

An automated vacuum system  

SciTech Connect

Software tools available with the Ground Test Accelerator (GTA) control system provide the capability to express a control problem as a finite state machine. System states and transitions are expressed in terms of accelerator parameters and actions are taken based on state transitions. This is particularly useful for sequencing operations which are modal in nature or are unwieldy when implemented with conventional programming. State diagrams are automatically translated into code which is executed by the control system. These tools have been applied to the vacuum system for the GTA accelerator to implement automatic sequencing of operations. With a single request, the operator may initiate a complete pump-down sequence. He can monitor the progress and is notified if an anomaly occurs requiring intervention. The operator is not required to have detailed knowledge of the vacuum system and is protected from taking inappropriate actions. 1 ref., 6 figs.

Atkins, W.H. (Oak Ridge National Lab., TN (USA)); Vaughn, G.D. (Los Alamos National Lab., NM (USA)); Bridgman, C. (Grumman Corp., Bethpage, NY (USA))

1991-01-01

424

Electrostatic Levitator Vacuum Chambers  

NASA Technical Reports Server (NTRS)

Optical prots ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), poisitioning lasers (one port is at center), and lamps (such as the deuterium arc lamp at right), and to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

1998-01-01

425

Electrostatic Levitator Vacuum Chamber  

NASA Technical Reports Server (NTRS)

Optical prots ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), poisitioning lasers (one port is at center), and lamps (arc lamp at right), and to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

1998-01-01

426

Spinning out of control: Wall turbulence over rotating discs  

NASA Astrophysics Data System (ADS)

The friction drag reduction in a turbulent channel flow generated by surface-mounted rotating disc actuators is investigated numerically. The wall arrangement of the discs has a complex and unexpected effect on the flow. For low disc-tip velocities, the drag reduction scales linearly with the percentage of the actuated area, whereas for higher disc-tip velocity, the drag reduction can be larger than the prediction found through the linear scaling with the actuated area. For medium disc-tip velocities, all the cases which display this additional drag reduction exhibit stationary-wall regions between discs along the streamwise direction. This effect is caused by the viscous boundary layer which develops over the portions of stationary wall due to the radial flow produced by the discs. For the highest disc-tip velocity, the drag reduction even increases by halving the number of discs. The power spent to activate the discs is instead independent of the disc arrangement and scales linearly with the actuated area for all disc-tip velocities. The Fukagata-Iwamoto-Kasagi identity and flow visualizations are employed to provide further insight into the dynamics of the streamwise-elongated structures appearing between discs. Sufficient interaction between adjacent discs along the spanwise direction must occur for the structures to be created at the disc side where the wall velocity is directed in the opposite direction to the streamwise mean flow. Novel half-disc and annular actuators are investigated to improve the disc-flow performance, resulting in a maximum of 26% drag reduction.

Wise, Daniel J.; Alvarenga, Claudia; Ricco, Pierre

2014-12-01

427

Adolescent disc dysplasia and back pain  

PubMed Central

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

Anakwenze, Okechukwu A.; Kancherla, Vamsi; Rendon, Norma

2010-01-01

428

Is vacuum dispersive?  

E-print Network

The question we ask is: does the speed of light {\\it{in vacuo}} depend on its frequency? While the answer is NO in the frame of classical physics, we point out that the opposite could be true if one takes into account the polarization of Dirac sea. We estimate the dependence of the index of refraction of vacuum + Dirac sea versus the wavelength of an incoming beam, and suggest a way to test this effect.

Yves Pomeau

2014-09-02

429

The vacuum energy crisis  

E-print Network

The smallness of the vacuum energy density and its near coincidence with the average matter density of the universe are naturally explained by anthropic selection. An alternative explanation, based on the cyclic model of Steinhardt and Turok, does not address the coincidence problem and is therefore less convincing. This article appeared in ``Science'' (4 May 2006) as a ``perspective'' for Steinhardt and Turok's paper in the same issue (astro-ph/0605173).

Alexander Vilenkin

2006-05-09

430

Shift in apparent contrast of disc at Secchi disc depth in coastal sea areas.  

PubMed

The relationship between Secchi disc depth and amount of suspended material in seawater varies depending on the particular marine area. To identify the cause of this dependence, we calculated the apparent contrast (C (SD)) at each Secchi disc depth in different coastal sea areas. When the turbidity from the surface to the Secchi disc depth was uniform, the C (SD) was distributed in the range of 1.3 to 0.001 for a Secchi disc depth (Z (SD)) of 2-18 m. Z (SD) tended to decrease as C (SD) became larger. The dominant wavelength for the sea color was 475-500 nm for a Secchi disc depth of 13-18 m, and 500-575 nm for a Z(SD) of 2-6 m, shifting to longer wavelengths as the Secchi disc depth increased. That is, when Z (SD) decreased, the dominant wavelength of the sea color, and the C (SD) increased simultaneously. This phenomenon seems to occur because the contrast threshold for the human eye is higher at longer wavelengths. In other words, the contrast threshold is visibly indistinguishable when the apparent contrast in ocean waters with low Secchi disc depths is high. This phenomenon occurs because the human eye is affected by the color of the sea. PMID:22688411

Arakawa, Hisayuki; Inada, Mari; Choi, Sokjin; Narita, Miho

2013-03-01

431

The runaway instability of thick discs around black holes. II. Non constant angular momentum discs  

E-print Network

We present results from a comprehensive number of relativistic, time-dependent, axisymmetric simulations of the runaway instability of non-constant angular momentum thick discs around black holes. This second paper extends earlier results where only constant angular momentum discs were considered. All relevant aspects of the theory of stationary thick discs around rotating black holes, necessary to build the initial state in our simulations, are presented in great detail. The angular momentum of the discs is assumed to increase outwards with the radial distance according to a power law. The main simplifying assumptions of our approach are not to include magnetic fields and self-gravity in the discs. Furthermore, the dynamics of the spacetime is accounted for by computing the transfer of mass and angular momentum from the disc to the black hole through the event horizon : the evolution of the central black hole is assumed to follow a sequence of Kerr black holes of increasing mass and spin. In agreement with previous results based on stationary models we find that by allowing the mass and the spin of the black hole to grow, constant angular momentum discs rapidly become unstable on a dynamical timescale. The comparison with the results of paper I shows that the effect of the angular momentum transfer from the torus to the black hole is to make constant angular momentum discs less unstable, increasing the timescale of the instability. However, we find that non-constant angular momentum discs are dramatically stabilized for very small values of the angular momentum slope. Our time-dependent simulations confirm, thus, the predictions of stationary studies concerning the stabilizing effect of non-constant angular momentum distributions.

Frederic Daigne; Jose A. Font

2003-11-28

432

The effectiveness of percutaneous laser disc decompression for the prolapsed lumbar intervertebral disc  

NASA Astrophysics Data System (ADS)

Objective: to investigate the role of associated factors in the effectiveness of laser treatment for prolapsed lumber intervertebral disc. Method: 302 prolapsed lumber intervertebral discs in 212 patients were treated with percutaneous laser disc decompression (PLDD). Patients were followed up by 12month, the associated factors which affecting the effectiveness of treatment, ie age, duration of illness were analyzed. Results: Punctual Success rate was 100%. After 12 month's follow up, 86% successful outcomes were obtained, in which 93% successful outcomes were obtained in patients less than 50 years old, 92% successful outcomes was obtained in the patients whose duration of illness less than 1 year.

Mu, Ming Wei; Liu, Wei; Feng, Wei; Ma, Nan

2009-07-01

433

Vacuum Energy: Myths and Reality  

E-print Network

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...

Volovik, G E

2006-01-01

434

On outflowing viscous disc models for Be stars  

E-print Network

It is assumed that Be star discs are driven by viscosity. Emission from disc models is calculated and is confronted with continuum observations. It is found that the outflowing viscous disc models can reproduce the observed IR continuum emission. However, to exist as outflowing discs, either the discs are significantly acted upon by the stellar radiation field and/or there is significant cooling with radius in the disc. The energy generated via viscous dissipation is calculated and shown to play only a minor role in the energy balance of the disc. A scenario whereby a B star may change into a Be star (and vice versa) by generating (reaccreting) the disc is suggested.

John M. Porter

1999-06-24

435

Understand vacuum-system fundamentals  

SciTech Connect

Crude vacuum unit heavy vacuum gas-oil (HVGO) yield is significantly impacted by ejector-system performance, especially at conditions below 20 mmHg absolute pressure. A deepcut vacuum unit, to reliably meet the yields, calls for proper design of all the major pieces of equipment. Ejector-system performance at deepcut vacuum column pressures may be independently or concurrently affected by: atmospheric column overflash, stripper performance or cutpoint; vacuum column top temperature and heat balance; light vacuum gas-oil (LVGO) pumparound entrainment to the ejector system; cooling-water temperature; motive steam pressure; non-condensible loading, either air leakage or cracked light-end hydrocarbons; condensible hydrocarbons; intercondenser or aftercondenser fouling ejector internal erosion or product build-up; and system vent back pressure. The paper discusses gas-oil yields; ejector-system fundamentals; condensers; vacuum-system troubleshooting; process operations; and a case study of deepcut operations.

Martin, G.R. (Process Consulting Services, Grapevine, TX (United States)); Lines, J.R. (Graham Manufacturing Co., Inc., Batavia, NY (United States)); Golden, S.W. (Glitsch, Inc., Dallas, TX (United States))

1994-10-01

436

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

NASA Technical Reports Server (NTRS)

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.

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

2014-01-01

437

Miniaturized Optical Pickup and Mechanism for Mobile Optical Disc Drive  

Microsoft Academic Search

Recently, the market for portable instruments has been increasing markedly. If a very small optical disc drive can be realized, it is expected that a new market for memories will be created, because the running cost of an optical disc is very low. The main issues in such realization are miniaturization of a loading mechanism with a disc cartridge and

Mitsuhiro Togashi; Takayuki Sasaoka; Ho-Cheol Lee; Ho-Seop Jeong

2004-01-01

438

Chapter 2 Requirements for an artificial intervertebral disc  

Microsoft Academic Search

Intervertebral disc degeneration is an important social and economical problem. Presently available artificial intervertebral discs (AIDs) are insufficient and the main surgical intervention is still spinal fusion. The objective of the present study is to present a list of requirements for the development of an AID which could replace the human lumbar intervertebral disc and restores its function. The list

M. F. Eijkelkamp; C. C. van Donkelaar; A. G. Veldhuizen; J. R. van Horn; J. M. Huyghe; G. J. Verkerke

2001-01-01

439

Interactive Optical Disc Systems: Part 1: Analog Storage.  

ERIC Educational Resources Information Center

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)

Hessler, David W.

1984-01-01

440

DISC1–ATF4 transcriptional repression complex: dual regulation of the cAMP-PDE4 cascade by DISC1  

E-print Network

Disrupted-In-Schizophrenia 1 (DISC1), a risk factor for major mental illnesses, has been studied extensively in the context of neurodevelopment. However, the role of DISC1 in neuronal signaling, particularly in conjunction ...

Ishizuka, K

441

Foramen of Huschke (tympanicum) in a Nigerian male with articular soft-tissue herniation into the external auditory meatus.  

PubMed

The protrusion of articular soft-tissue from the temporomandibular joint (TMJ) into the external ear in the absence of trauma, neoplasm or inflammation is rare. We present below a Nigerian adult male with retrodiscal herniation of soft-tissues of the TMJ into the external auditory meatus through a persistent foramen of Huschke. We are not aware of any reports of this developmental defect or its prevalence in the Nigerian medical literature. Therefore, this case is presented to heighten the index of suspicion of physicians when managing patients with otorrhea and otalgia; which is often primarily diagnosed or misdiagnosed as otitis externa. This will help avoid complications associated with the anomaly, some of which could be very serious. PMID:25287039

Olarinoye-Akorede, S A; Olanrewaju, I S; Suleiman, A O

2014-01-01

442

Discovery of the DISC1 Gene  

NSDL National Science Digital Library

Cytogenetics is the study of chromosomes and how changes in chromosome structure and number affect the individual. In this video, Professor Porteous describes the process of hunting for the DISC1 gene, a gene disrupted by a balanced translocation on chromosome 1q42.

2009-04-14

443

Spectra of thermally unstable slim discs  

E-print Network

Thermal instability driven by radiation pressure might be relevant for intrinsically bright accreting sources. The most promising candidate where this instability seems to be at work is one of the two known galactic superluminal sources, GRS 1915+105 (Belloni et al. 1997). In spite of being of relevance, this scenario has not yet been confirmed by proper time-dependent modelling. Non-linear time-dependent calculations performed by Szuszkiewicz and Miller (1998) show that thermally unstable discs undergo limit-cycle behaviour with successive evacuation and refilling of the central parts of the disc. This evolution is very similar to the one proposed by Belloni et al. (1997) in their phenomenological model. Further investigations are needed to confirm the thermal instability being operational in this source. First of all the spectra emitted from the disc during its evolution should be calculated and compared with observations. Here such spectra are computed assuming local blackbody emission from the best studied transonic disc model.

Ewa Szuszkiewicz; Roberto Turolla; Luca Zampieri

2000-11-21

444

Diagnostic Testing for Degenerative Disc Disease  

PubMed Central

The diagnostic of degenerative disc disease should be reached with the help of various diagnostic studies. This article briefly review the information gained by the following tests: radiographs, computed tomography, magnetic resonance, and discography. The article explains how each modality provides a piece of the diagnostic puzzle and how discography confirms the origin of the patient's pain. PMID:22844603

Hasz, Michael W.

2012-01-01

445

Frictional Torque on a Rotating Disc  

ERIC Educational Resources Information Center

Resistance to motion often includes a dry frictional term independent of the speed of an object and a fluid drag term varying linearly with speed in the viscous limit. (At higher speeds, quadratic drag can also occur.) Here, measurements are performed for an alumini