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1

Spontaneous resorption of a large cervical herniated nucleus pulposus.  

PubMed

The majority of patients with symptomatic herniated discs can be successfully and conservatively managed and can achieve clinical improvement without surgical intervention. Resorption of the herniated nucleus pulposus (HNP) is 1 conservative mechanism for clinical improvement. We present the case of a 76-year-old healthy man with acute cervical radicular right arm pain and positive Spurling test. Magnetic resonance imaging (MRI) showed a large disc extrusion behind the C6 vertebral body, causing severe central canal stenosis and right-greater-than-left foraminal stenosis. The patient did not want surgical intervention, and his symptoms resolved with conservative treatment. A follow-up MRI 7 months after his initial presentation showed almost complete resorption of the herniated disc. The patient returned to his normal activities and has not had recurrence of symptoms for 2 years. This report provides an interesting example of complete resorption of a large, extruded cervical herniated disc in a symptomatic patient and a review of the literature on resorption of herniated discs. The review suggests that larger herniations with an epidural location (penetration of the posterior longitudinal ligament) have a greater chance of resorption. PMID:25046190

Cvetanovich, Gregory L; Hsu, Andrew R; Frank, Rachel M; An, Howard S; Andersson, Gunnar B

2014-07-01

2

Identification of novel nucleus pulposus markers  

PubMed Central

Mesenchymal stem-cell based therapies have been proposed as novel treatments for intervertebral disc degeneration, a prevalent and disabling condition associated with back pain. The development of these treatment strategies, however, has been hindered by the incomplete understanding of the human nucleus pulposus phenotype and by an inaccurate interpretation and translation of animal to human research. This review summarises recent work characterising the nucleus pulposus phenotype in different animal models and in humans and integrates their findings with the anatomical and physiological differences between these species. Understanding this phenotype is paramount to guarantee that implanted cells restore the native functions of the intervertebral disc. Cite this article: Bone Joint Res 2013;2:169–78. PMID:23958792

Rodrigues-Pinto, R.; Richardson, S. M.; Hoyland, J. A.

2013-01-01

3

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

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

4

Development of injectable hydrogels for nucleus pulposus replacement  

NASA Astrophysics Data System (ADS)

Intervertebral disc degeneration has been reported as the underlying cause for 75% of cases of lower back pain and is marked by dehydration of the nucleus pulposus within the intervertebral disc. There have been many implant designs to replace the nucleus pulposus. Some researchers have proposed the replacement of the nucleus pulposus with hydrogel materials. The insertion of devices made from these materials further compromises the annulus of the disc. An ideal nucleus replacement could be injected into the disc space and form a solid in vivo. However, injectable replacements using curing elastomers and thermoplastic materials are not ideal because of the potentially harmful exothermic heat evolved from their reactions and the toxicity of the reactants used. We propose a hydrogel system that can be injected as a liquid at 25°C and solidified to yield a hydrogel within the intervertebral disc at 37°C. In aqueous solutions, these polymers have Lower Critical Solution Temperatures (LCST) between 25-37°C, making them unique candidate materials for this application. Poly(N-isopropylacrylamide) (PNIPAAm) is the most widely studied LCST polymer due to its drastic transition near body temperature. However, by itself, pure PNIPAAm forms a hydrogel that has low water content and can readily undergo plastic deformation. To increase the water content and impart elasticity to PNIPAAm hydrogels, grafted and branched hydrogel systems were created that incorporated the thermogelling PNIPAAm and hydrophilic poly(ethylene glycol) (PEG). In this research, the effects of polymer composition and monomer to initiator ratio, which controls polymer MW, on the in vitro swelling properties (mass, chemical, and compressive mechanical stability) of hydrogels formed from aqueous solutions of these polymers were evaluated. Immersion studies were also conducted in solutions to simulate the osmotic environment of the nucleus pulposus. The effects of repeated compression and unloading cycles on the water content and dimensional recovery of hydrogels made from three candidate polymer formulations were also determined. Unlike PNIPAAm and PEG grafted PNIPAAm hydrogels, PEG branched hydrogels have covalently linked networks. Addition of 7 mol% PEG branches to PNIPAAm resulted in a hydrogel with a higher water content and better elastic recovery than hydrogels made from pure PNIPAAm. PEG branched PNIPAAm hydrogels were shown to have mass, chemical, and compressive mechanical stability in vitro. Furthermore, these hydrogels showed superior dimensional recovery after compressive cycling than pure PNIPAAm and PEG grafted PNIPAAm hydrogels. The 7 mol% PEG branched PNIPAAm hydrogels have suitable swelling and mechanical properties to potentially serve as a nucleus pulposus replacement.

Thomas, Jonathan D.

5

A complex interaction between Wnt signaling and TNF-? in nucleus pulposus cells  

PubMed Central

Introduction Increased expression of the proinflammatory cytokine TNF-? in intervertebral discs (IVDs) leads to inflammation, which results in progressive IVD degeneration. We have previously reported that activation of Wnt-?-catenin (hereafter called Wnt) signaling suppresses the proliferation of nucleus pulposus cells and induces cell senescence, suggesting that Wnt signaling triggers the process of degeneration of the IVD. However, it is not known whether cross talk between TNF-? and Wnt signaling plays a role in the regulation of nucleus pulposus cells. The goal of the present study was to examine the effect of the interaction between Wnt signaling and the proinflammatory cytokine TNF-? in nucleus pulposus cells. Methods Cells isolated from rat nucleus pulposus regions of IVDs were cultured in monolayers, and the expression and promoter activity of Wnt signaling and TNF-? were evaluated. We also examined whether the inhibition of Wnt signaling using cotransfection with Dickkopf (DKK) isoforms and Sclerostin (SOST) could block the effects of pathological TNF-? expression in nucleus pulposus cells. Results TNF-? stimulated the expression and promoter activity of Wnt signaling in nucleus pulposus cells. In addition, the activation of Wnt signaling by 6-bromoindirubin-3?-oxime (BIO), which is a selective inhibitor of glycogen synthase kinase 3 (GSK-3) activity that activates Wnt signaling, increased TNF-? expression and promoter activity. Conversely, the suppression of TNF-? promoter activity using a ?-catenin small interfering RNA was evident. Moreover, transfection with DKK-3, DKK-4, or SOST, which are inhibitors of Wnt signaling, blocked Wnt signaling-mediated TNF-? activation; these effects were not observed for DKK-1 or DKK-2. Conclusions Here, we have demonstrated that Wnt signaling regulates TNF-? and that Wnt signaling and TNF-? form a positive-feedback loop in nucleus pulposus cells. The results of the present study provide in vitro evidence that activation of Wnt signaling upregulates the TNF-? expression and might cause the degeneration of nucleus pulposus cells. We speculate that blocking this pathway might protect nucleus pulposus cells against degeneration. PMID:24286133

2013-01-01

6

Inflammatory Cytokines Induce NOTCH Signaling in Nucleus Pulposus Cells  

PubMed Central

The objective of the study was to investigate how inflammatory cytokines, IL-1?, and TNF-? control NOTCH signaling activity in nucleus pulposus (NP) cells. An increase in expression of selective NOTCH receptors (NOTCH1 and -2), ligand (JAGGED2), and target genes (HES1, HEY1, and HEY2) was observed in NP cells following cytokine treatment. A concomitant increase in NOTCH signaling as evidenced by induction in activity of target gene HES1 and HEY1 promoters and reporter 12xCSL was seen. Moreover, treatment increased activity of a 2-kb NOTCH2 promoter. Treatment of cells with NF-?B and MAPK inhibitors abolished the inductive effect of cytokines on NOTCH2 promoter and its expression. Gain and loss-of-function studies confirmed the inductive effect of p65 on NOTCH2 promoter activity. In contrast, p50 blocked the cytokine induction of promoter activity. Supporting promoter studies, lentiviral delivery of sh-p65, and sh-IKK? significantly decreased cytokine dependent change in NOTCH2 expression. Interestingly, MAPK signaling showed an isoform-specific control of NOTCH2 promoter; p38?/?2/?, ERK1, and ERK2 contributed to cytokine dependent induction, whereas p38? played no role. Analysis of human NP tissues showed that NOTCH1 and -2 and HEY2 expression correlated with each other. Moreover, expression of NOTCH2 and IL-1? as well as the number of cells immunopositive for NOTCH2 significantly increased in histologically degenerate discs compared with non-degenerate discs. Taken together, these results explain the observed dysregulated expression of NOTCH genes in degenerative disc disease. Thus, controlling IL-1? and TNF-? activities during disc disease may restore NOTCH signaling and nucleus pulposus cell function. PMID:23589286

Wang, Hua; Tian, Ye; Wang, Jianru; Phillips, Kate L. E.; Binch, Abbie L. A.; Dunn, Sara; Cross, Alison; Chiverton, Neil; Zheng, Zhaomin; Shapiro, Irving M.; Le Maitre, Christine L.; Risbud, Makarand V.

2013-01-01

7

Physical analysis of collagen-GAG composite scaffolds for nucleus pulposus tissue regeneration  

E-print Network

In this study biomaterial scaffolds for regeneration of nucleus pulposus were developed by freeze drying slurries with different proportions of collagen II (CII), chondroitin-6-sulfate (CS), and hyaluronic acid (HA). The ...

Simson, Jacob A

2008-01-01

8

Advanced glycation end products in degenerative nucleus pulposus with diabetes.  

PubMed

Diabetes mellitus (DM) has been clinically proved as a risk factor of disc degeneration, and the accumulation of advanced glycation end products (AGEs) is known to be potentially involved in diabetes. The purpose of this study is to investigate the effect of AGEs in the degeneration process of diabetic nucleus pulposus (NP) in rats and humans. Diabetic NP cells from rat coccygeal discs were treated with different concentrations of AGEs (0, 50, and 100?µg/ml) for 3 days, and mRNA expressions of MMP-2 and RAGE were measured by real-time RT-PCR. In addition, conditioned medium from NP cells was used to analyze protein expression of MMP-2 activity and ERK by gelatin zymography and Western blot. These experiments were repeated using human intervertebral disc samples. The immunohistochemical expression of AGEs was significantly increased in diabetic discs. In response to AGEs, an increase of MMP-2, RAGE, and ERK at both mRNA and protein expression levels was observed in diabetic NP cells. The findings suggest that AGEs and DM are associated with disc degeneration in both species. Hyperglycemia in diabetes enhances the accumulation of AGEs in the NP and triggers disc degeneration. PMID:24151186

Tsai, Tsung-Ting; Ho, Natalie Yi-Ju; Lin, Ying-Ting; Lai, Po-Liang; Fu, Tsai-Sheng; Niu, Chi-Chien; Chen, Lih-Huei; Chen, Wen-Jer; Pang, Jong-Hwei S

2014-02-01

9

Identification of transglutaminase substrates from porcine nucleus pulposus as potential amplifiers in cross-linking cell scaffolds.  

PubMed

Nucleus pulposus from the porcine intervertebral disc was separated chromatographically to discover substrates of microbial transglutaminase. Highly purified proteins were prepared, among them type II collagen, the major protein of the nucleus pulposus. Determination of substrates was performed by transglutaminase-mediated incorporation of biotinylated probes displaying several glutamine and lysine donor proteins. Type II collagen was only labeled if smaller nucleus pulposus proteins were present. One of the modulating proteins was serotransferrin, a lysine donor substrate of bacterial transglutaminase. An additional substrate was the carboxy-terminal propeptide of type II collagen, chondrocalcin. Chondrocalcin, a regulator of type II collagen fibrillogenesis, occurs abundantly in juvenile cartilage and nucleus pulposus. Accordingly, the protein may be regarded as an excellent additive for the preparation of injectable stem cells in nucleus pulposus-like matrices cross-linked by microbial transglutaminase. PMID:23495872

Gebauer, Elke; Goßla, Elke; Kwas, Carolin; Salzig, Denise; Schmiermund, Alexandra; Czermak, Peter; Fuchsbauer, Hans-Lothar

2013-05-13

10

In vitro measurement of nucleus pulposus swelling pressure: A new technique for studies of spinal adaptation to gravity  

NASA Technical Reports Server (NTRS)

Swelling of the intervertebral disc nucleus pulposus is altered by posture and gravity. We have designed and tested a new osmometer for in vitro determination of nucleus pulposus swelling pressure. The functional principle of the osmometer involves compressing a sample of nucleus pulposus with nitrogen gas until saline pressure gradients across a 0.45 microns Millipore filter are eliminated. Swelling pressure of both pooled dog and pooled pig lumbar disc nucleus pulposus were measured on the new osmometer and compared to swelling pressures determined using the equilibrium dialysis technique. The osmometer measured swelling pressures comparable to those obtained by the dialysis technique. This osmometer provides a rapid, direct, and accurate measurement of swelling pressure of the nucleus pulposus.

Hargens, A. R.; Glover, M. G.; Mahmood, M. M.; Gott, S.; Garfin, S. R.; Ballard, R.; Murthy, G.; Brown, M. D.

1992-01-01

11

Molecular phenotypes of notochordal cells purified from immature nucleus pulposus.  

PubMed

The immature nucleus pulposus (NP) is populated by cells of notochordal-origin that are larger and contain an extensive cytoskeletal network and numerous vacuoles. The disappearance of these cells with age is believed important in regulating metabolic shifts that may contribute to age-related disc degeneration. The precise biological function of these notochordal cells in the immature NP remains unclear, however, because of challenges in studying the mixed cell population in the NP. In this study, notochordal-like cells were purified from immature NP cells using a new fluorescence-activated cell sorting (FACS) protocol with auto-fluorescence and size analysis. The unique molecular phenotypes of sorted notochordal-like cells were characterized by the mRNA expression pattern for key matrix proteins and modulators, and by the expression of cell-matrix receptor integrin subunits. An FACS analysis showed that the immature NP contained a majority of cells that were larger than anulus fibrosus (AF) cells and with fluorescence higher than AF cells. In comparison with the small NP cells separated by the FACS protocol, sorted notochordal-like cells expressed lower mRNA levels of type I collagen, biglycan, TIMP1, HSP70 and c-fos, and did not express detectable mRNA levels of decorin, lumican, multiple MMPs or IL-1beta via real-time quantitative RT-PCR. A greater number of these notochordal-like cells also expressed the higher levels of alpha6, alpha1 and beta1 integrin subunits as compared to small NP cells. Together, our results point towards a unique molecular phenotype for these notochordal-like cells of NP, characterized by the absence of gene expression for specific small proteoglycans and higher protein expression of integrin subunits that regulate interactions with collagens and laminin. Future studies will be important for revealing if this unique molecular profile is coordinated with functional differences in pericellular matrix regions and/or integrin-mediated cell-matrix interactions for these notochordal-like cells within the NP. PMID:16547755

Chen, Jun; Yan, Wei; Setton, Lori A

2006-08-01

12

MiR-27a Regulates Apoptosis in Nucleus Pulposus Cells by Targeting PI3K  

PubMed Central

The precise role of apoptosis in the pathogenesis of intervertebral disc degeneration (IDD) remains to be elucidated. We analyzed degenerative nucleus pulposus (NP) cells and found that the expression of miR-27a was increased. The overexpression of miR-27a was further verified using real-time RT-PCR. Bioinformatics target prediction identified phosphoinositide-3 kinases (PI3K) as putative targets of miR-27a. Furthermore, miR-27a inhibited PI3K expression by directly targeting their 3’-UTRs, and this inhibition was abolished by mutation of the miR-27a binding sites. Various cellular processes including cell growth, proliferation, migration and adhesion are regulated by activation of the PI3K/AKT signaling pathway, and nucleus pulposus cells are known to strongly express the phosphorylated survival protein AKT. Our results identify PI3K as a novel target of miR-27a. Upregulation of miR-27a thus targets PI3K, initiating apoptosis of nucleus pulposus cells. This present study revealed that downregulated miR-27a might develop a novel intervention for IDD treatment through the prevention of apoptosis in Nucleus pulposus Cells. PMID:24086481

Chen, Huajiang; Yuan, Wen; Wang, Jianxi; Tang, Xianye

2013-01-01

13

Curing kinetics and mechanical properties of a composite hydrogel for the replacement of the nucleus pulposus  

E-print Network

curable hydrogel with properties similar to the native nucleus pulposus of intervertebral disc. Neat has an influence on the time of curing and final shear stiffness of the material. NFC does not alter. 1. Introduction Lower back pain is mostly due to intervertebral disc (IVD) degeneration

Guerraoui, Rachid

14

Morphologic characteristics of processes of nucleus pulposus cells in adult human intervertebral disc  

NASA Astrophysics Data System (ADS)

To explore morphologic characterizatics of cellular processes from adult human nucleus pulposus cells, the nucleus pulposus of adult human intervertebral disc were obtained from 8 patients (Thompson's grade I~II) and then the tissues specimens were carried out by frozen section and electron microscopic section as well as cell isolation and cultured, processes of nucleus pulposus cells were examined using light microscopy, laser scanning confocal microscopy and transmission electron microscopy. When examined at both the confocal and electron microscope level, all the cells possessed the processes and adjacent nucleus pulposus cells processes possessed a gap junction. But elongated and round cells can be examined when NP cells were monolayer cultured. The rate of elongated cells to round cells is 2.3 to 1. The elongated cells protrude along with the long axis of cell body without second processes. Dendritic processes of round cells protrude to all directions from the cell body with multiple-level processes. Processes are one of the morphologic characteristics of intervertebral disc cells which are different from articular cartilage chondrocytes. The research on processes functions will be helpful to understand pathomechanism of intervertebral disc degradation and open a new approach for cytobiology treatment of the intervertebral disc diseases.

Liu, Xiaoyun; Wu, Xinghuo; Hui, Liu; Xu, Weihua; Liu, Xianze; Yang, Shuhua

2008-12-01

15

Notochordal cell conditioned medium stimulates mesenchymal stem cell differentiation toward a young nucleus pulposus phenotype  

Microsoft Academic Search

Introduction  Mesenchymal stem cells (MSCs) offer promise for intervertebral disc (IVD) repair and regeneration because they are easily\\u000a isolated and expanded, and can differentiate into several mesenchymal tissues. Notochordal (NC) cells contribute to IVD development,\\u000a incorporate into the nucleus pulposus (NP), and stimulate mature disc cells. However, there have been no studies investigating\\u000a the effects of NC cells on adult stem

Casey L Korecki; Juan M Taboas; Rocky S Tuan; James C Iatridis

2010-01-01

16

Exhaustion of nucleus pulposus progenitor cells with ageing and degeneration of the intervertebral disc  

PubMed Central

Despite the high prevalence of intervertebral disc disease, little is known about changes in intervertebral disc cells and their regenerative potential with ageing and intervertebral disc degeneration. Here we identify populations of progenitor cells that are Tie2 positive (Tie2+) and disialoganglioside 2 positive (GD2+), in the nucleus pulposus from mice and humans. These cells form spheroid colonies that express type II collagen and aggrecan. They are clonally multipotent and differentiated into mesenchymal lineages and induced reorganization of nucleus pulposus tissue when transplanted into non-obese diabetic/severe combined immunodeficient mice. The frequency of Tie2+ cells in tissues from patients decreases markedly with age and degeneration of the intervertebral disc, suggesting exhaustion of their capacity for regeneration. However, progenitor cells (Tie2+GD2+) can be induced from their precursor cells (Tie2+GD2?) under simple culture conditions. Moreover, angiopoietin-1, a ligand of Tie2, is crucial for the survival of nucleus pulposus cells. Our results offer insights for regenerative therapy and a new diagnostic standard. PMID:23232394

Sakai, Daisuke; Nakamura, Yoshihiko; Nakai, Tomoko; Mishima, Taishi; Kato, Shunichi; Grad, Sibylle; Alini, Mauro; Risbud, Makarand V.; Chan, Danny; Cheah, Kathryn S.E.; Yamamura, Ken-ichi; Masuda, Koichi; Okano, Hideyuki; Ando, Kiyoshi; Mochida, Joji

2012-01-01

17

Percutaneous Disc Decompression with Nucleoplasty-Volumetry of the Nucleus Pulposus Using Ultrahigh-Field MRI  

PubMed Central

Purpose To evaluate changes in nucleus pulposus volume as a potential parameter for the effects of disc decompression. Methods Fifty-two discs (T8 to L1) were extracted from 26 pigs and separated into thoracic (T8 to T11) and thoracolumbar discs (T12 to L1). The discs were imaged using 7.1 Tesla ultrahigh-field magnetic resonance imaging (MRI) with acquisition of axial T2-weighted turbo spin-echo sequences for determination of baseline and postinterventional nucleus pulposus volumes. Volumes were calculated using OsiriX® (http://www.osirix-viewer.com). After randomization, one group was treated with nucleoplasty, while the placebo group was treated with an identical procedure but without coblation current. The readers analyzing the MR images were blinded to the kind of procedure performed. Baseline and postinterventional volumes were compared between the nucleoplasty and placebo group. Results Average preinterventional nucleus volume was 0.799 (SD: 0.212) ml. Postinterventional volume reduction in the nucleoplasty group was significant at 0.052 (SD: 0.035) ml or 6.30% (p<0.0001) (thoracic discs) and 0.082 (SD: 0.042) ml or 7.25% (p?=?0.0078) (thoracolumbar discs). Nucleoplasty achieved volume reductions of 0.114 (SD: 0.054) ml or 14.72% (thoracic) and 0.093 (SD: 0.081) ml or 11.61% (thoracolumbar) compared with the placebo group. Conclusions Nucleoplasty significantly reduces thoracic and thoracolumbar nucleus pulposus volumes in porcine discs. PMID:22848512

Kasch, Richard; Mensel, Birger; Schmidt, Florian; Drescher, Wolf; Pfuhl, Ralf; Ruetten, Sebastian; Merk, Harry R.; Kayser, Ralph

2012-01-01

18

The effects of epidural application of allografted nucleus pulposus in rats on cytokine expression, limb withdrawal and nerve root discharge  

Microsoft Academic Search

This study investigated cytokine expression, behavioral and neurophysiologic changes in Lewis rats whose lumbar nerve roots were exposed to nucleus pulposus (NP). Allografted NP or fat was implanted over the left L5 nerve root. Sham rats had no NP or fat implantation. Control rats had no surgery. Rats were allowed to survive for 7 days and were tested daily for hind-paw

Srinivasu Kallakuri; Tsuneo Takebayashi; A. Cuneyt Ozaktay; Chaoyang Chen; Shangyou Yang; Paul H. Wooley; John M. Cavanaugh

2005-01-01

19

Effects of the ablation of the nucleus pulposus on the vibrational behavior of the lumbosacral hinge.  

PubMed

This study was designed to investigate the respective damping properties of the annulus fibrosus and nucleus pulposus of the intervertebral disc during propagation of vibration waves through the osteoligamento-muscular axis of the spine. The study was conducted on a 8-10 kg deeply anesthetized baboon. In the first surgical phase five accelerometers were implanted in the first sacral vertebra and on the anterior side of the four lower lumbar vertebrae. The bioinstrumented animal was placed in a restraining chair and exposed to narrow-bandwidth (0-100 Hz) 0.16 G RMS random vibration. Once data was recorded, the nuclei pulposi of the studied discs were removed by suction, the surrounding annuli remaining intact. The still deeply anesthetized animal was again exposed to the same 0-100 Hz, 0.16 G RMS vibration. Results were analyzed and their reproducibility was tested on three animals. PMID:6643515

Quandieu, P; Pellieux, L; Lienhard, F; Valezy, B

1983-01-01

20

Regulatory Role of Hypoxia Inducible Factor in the Biological Behavior of Nucleus Pulposus Cells  

PubMed Central

Intervertebral disc (IVD) degeneration is implicated as a major cause of low back pain. The alternated phenotypes, reduced cell survival, decreased metabolic activity, loss of matrix production and dystrophic mineralization of nucleus pulposus (NP) cells may be key contributors to progressive IVD degeneration. IVD is the largest avascular structure in the body, characterized by low oxygen tension in vivo. Hypoxia-inducible factor (HIF) is a master transcription factor that is induced upon hypoxia and directs coordinated cellular responses to hypoxic environments. This review summarizes relevant studies concerning the involvement of HIF in the regulation of biological behaviors of NP cells. We describe current data on the expression of HIF in NP cells and further discuss the various roles that HIF plays in the regulation of the phenotype, survival, metabolism, matrix production and dystrophic mineralization of NP cells. Here, we conclude that HIF may be a promising target for the prevention and treatment of IVD degeneration. PMID:23709411

Li, Hao; Liang, Cheng Zhen

2013-01-01

21

Magnetic resonance imaging of adolescent disc herniation.  

PubMed

Magnetic resonance imaging (MRI) was used to compare the appearance of the spine in 20 adolescents with proven symptomatic intervertebral disc herniations with that in 20 asymptomatic patients who acted as controls. Abnormality in the signal from the nucleus pulposus of one or more discs was present in all patients, while only four of the 20 controls had any abnormal signals. In all the patients the symptomatic disc produced an abnormal signal and in most a herniated fragment of the nucleus pulposus was identified. Fifteen of the 20 patients had multiple-disc abnormality: six had three abnormal discs and nine had two. This suggests there was an underlying diathesis in patients who later developed disc herniation. PMID:3680327

Gibson, M J; Szypryt, E P; Buckley, J H; Worthington, B S; Mulholland, R C

1987-11-01

22

[Diagnostics and therapy of spinal disc herniation].  

PubMed

Degenerative processes in a movement segment of the vertebral column, which can potentially give rise to herniation of elements of the nucleus pulposus, are complex and of variable clinical and radiological dimensions; however the mere assumption that degenerative changes precede disc herniation remains a matter of debate. By definition, spinal disc herniation (SDH) refers to components of the gelatinous nucleus pulposus protruding beyond the dorsal level of the vertebral body margin through tears in the annulus fibrosus. Clinical presentation may include pain, paresis and sensory disturbances. Magnetic resonance imaging (MRI) is considered the gold standard in the diagnosis of SDH. In the majority of patients a conservative approach with physical therapy exercises and adequate analgesic and antiphlogistic medical treatment results in a substantial improvement of symptoms. PMID:25398570

Zimmer, A; Reith, W

2014-11-01

23

MicroRNA-10b Promotes Nucleus Pulposus Cell Proliferation through RhoC-Akt Pathway by Targeting HOXD10 in Intervetebral Disc Degeneration  

PubMed Central

Aberrant proliferation of nucleus pulposus cell is implicated in the pathogenesis of intervertebral disc degeneration. Recent findings revealed that microRNAs, a class of small noncoding RNAs, could regulate cell proliferation in many pathological conditions. Here, we showed that miR-10b was dramatically upregulated in degenerative nucleus pulposus tissues when compared with nucleus pulposus tissues isolated from patients with idiopathic scoliosis. Moreover, miR-10b levels were associated with disc degeneration grade and downregulation of HOXD10. In cultured nucleus pulposus cells, miR-10b overexpression stimulated cell proliferation with concomitant translational inhibition of HOXD10 whereas restored expression of HOXD10 reversed the mitogenic effect of miR-10b. MiR-10b-mediated downregulation of HOXD10 led to increased RhoC expression and Akt phosphorylation. Either knockdown of RhoC or inhibition of Akt abolished the effect of miR-10b on nucleus pulposus cell proliferation. Taken together, aberrant miR-10b upregulation in intervertebral disc degeneration could contribute to abnormal nucleus pulposus cell proliferation through derepressing the RhoC-Akt pathway by targeting HOXD10. Our study also underscores the potential of miR-10b and the RhoC-Akt pathway as novel therapeutic targets in intervertebral disc degeneration. PMID:24376640

Shen, Jianxiong; Wu, William K. K.; Liang, Jinqian; Weng, Xisheng; Qiu, Guixing

2013-01-01

24

Augmentation and repair tissue formation of the nucleus pulposus after partial nucleotomy in a rabbit model.  

PubMed

Disc degeneration alters disc height and mechanics of the spinal column and is associated with lower back pain. In preclinical studies gel-like materials or resorbable polymer-based implants are frequently used to rebuild the nucleus pulposus, aiming at tissue regeneration and restoration of tissue function. To compare the outcome of tissue repair, freeze-dried resorbable polyglycolic acid-hyaluronan (PGA/HA) implants without any bioactive components or bioactivated fibrin (fibrin-serum) was used in a degenerated disc disease model in New Zealand white rabbits. Animals with partial nucleotomy only served as controls. The T2-weighted/fat suppression sequence signal intensity in the nuclear region of operated discs as assessed by magnet resonance imaging was reduced in operated compared to healthy discs, indicating loss of water and did not change from week 1 to month 6 after surgery. Quantification of histological and immunohistochemical staining indicated that the implantation of PGA/HA leads to significantly more repair tissue compared to nucleotomy only. Type II collagen content of the repair tissue formed after PGA/HA or fibrin-serum treatment is significantly increased compared to controls with nucleotomy only. The data indicate that intervertebral disc augmentation after nucleotomy has a positive effect on repair tissue formation and type II collagen deposition as shown in the rabbit model. PMID:25287887

Endres, M; Zenclussen, M L; Casalis, P A; Freymann, U; Gil Garcia, S; Krueger, J P; Thomale, U-W; Woiciechowsky, C; Kaps, C

2014-12-01

25

Monitoring of the effect of intervertebral disc nucleus pulposus ablation by MRI.  

PubMed

In order to investigate intervertebral disc (IVD) degeneration and repair, a quantitative non-invasive tool is needed. Various MRI methods including qCPMG, which yields dipolar echo relaxation time (T(DE)), magnetization transfer contrast (MTC), and (1)H and (2)H double quantum filtered (DQF) MRI were used in the present work to monitor changes in rat IVD after ablation of the nucleus pulposus (NP), serving as a model of severe IVD degeneration. In the intact IVD, a clear distinction between the annulus fibrosus (AF) and the NP is obtained on T(2) and T(DE) weighted images as well as on MTC maps, reflecting the high concentration of ordered collagen fibers in the AF. After ablation of the NP, the distinction between the compartments is lost. T(2) and T(DE) relaxation times are short throughout the disc and MTC is high. (1)H and (2)H DQF signal, which in intact discs is obtained only for the AF, is now observable throughout the tissue. These results indicate that after ablation, there is an ingression of collagen fibers from the AF into the area that was previously occupied by the NP, as was confirmed by histology. PMID:20175140

Saar, Galit; Zilberman, Yoram; Shinar, Hadassah; Keinan-Adamsky, Keren; Pelled, Gadi; Gazit, Dan; Navon, Gil

2010-07-01

26

Characterization and mechanical performance study of silk/PVA cryogels: towards nucleus pulposus tissue engineering.  

PubMed

Poly (vinyl) alcohol (PVA) cryogels are reported in the literature for application in nucleus pulposus (NP) replacement strategies. However, these studies are mainly limited to acellular approaches-in part due to the high hydrophilicity of PVA gels that renders cellular adhesion difficult. Silk is a versatile biomaterial with excellent biocompatibility. We hypothesize that the incorporation of silk with PVA will (i) improve the cell-hosting abilities of PVA cryogels and (ii) allow better tailoring of physical properties of the composite cryogels for an NP tissue engineering purpose. 5% (wt/vol) PVA is blended with 5% silk fibroin (wt/vol) to investigate the effect of silk?:?PVA ratios on the cryogels' physical properties. Results show that the addition of silk results in composite cryogels that are able to swell to more than 10 times its original dry weight and rehydrate to at least 70% of its original wet weight. Adding at least 20% silk significantly improves surface hydrophobicity and is correlated with an improvement in cell-hosting abilities. Cell-seeded cryogels also display an increment in compressive modulus and hoop stress values. In all, adding silk to PVA creates cryogels that can be potentially used as NP replacements. PMID:25329452

Neo, Puay Yong; Shi, Pujiang; Goh, James Cho-Hong; Toh, Siew Lok

2014-01-01

27

Leptin Downregulates Aggrecan through the p38-ADAMST Pathway in Human Nucleus Pulposus Cells  

PubMed Central

The mechanistic basis of obesity-associated intervertebral disc degeneration (IDD) is unclear. Aberrant expression of aggrecan and its degrading enzymes ADAMTS-4 and ADAMTS-5 is implicated in the development of IDD. Here, we investigated the effect of leptin, a hormone with increased circulating levels in obesity, on the expression of aggrecan and ADAMTSs in primary human nucleus pulposus (NP) cells. Real-time PCR and Western blots showed that leptin increased the mRNA and protein expression of ADAMTS-4 and ADAMTS-5 and reduced the level of aggrecan in NP cells, accompanied by a prominent induction of p38 phosphorylation. Treatment of NP cells with SB203580 (a p38 inhibitor) abolished the regulation of aggrecan and ADAMTSs by leptin. Knockdown of ADAMTS-4 and ADAMTS-5 by siRNAs also attenuated the degradation of aggrecan in leptin-stimulated NP cells. To conclude, we demonstrated that leptin induces p38 to upregulate ADAMTSs and thereby promoting aggrecan degradation in human NP cells. These results provide a novel mechanistic insight into the molecular pathogenesis of obesity-associated IDD. PMID:25299465

Liang, Jinqian; Wu, William Ka Kei; Yu, Jun; Shen, Jianxiong

2014-01-01

28

An Injectable Nucleus Pulposus Implant Restores Compressive Range of Motion in the Ovine Disc  

PubMed Central

Study Design Investigation of injectable nucleus pulposus (NP) implant. Objective To assess the ability of a recently developed injectable hydrogel implant to restore non-degenerative disc mechanics through support of NP functional mechanics. Summary of Background Data While surgical intervention for low back pain is effective for some patients, treated discs undergo altered biomechanics and adjacent levels are at increased risk for accelerated degeneration. One potential treatment as an alternative to surgery for degenerated disc includes the percutaneous delivery of agents to support NP functional mechanics. The implants are delivered in a minimally invasive fashion, potentially on an outpatient basis, and do not preclude later surgical options. One of the challenges in designing such implants include the need to match key NP mechanical behavior and mimic the role of native non-degenerate NP in spinal motion. Methods The oxidized hyaluronic acid gelatin implant material was prepared. In vitro mechanical testing was performed in mature ovine bone-disc-bone units in three stages: intact, discectomy, and implantation vs. sham. Tested samples were cut axially for qualitative structural observations. Results Discectomy increased axial range of motion (ROM) significantly compared to intact. Hydrogel implantation reduced ROM 17% (p < 0.05) compared to discectomy and returned ROM to intact levels (ROM intact 0.71 mm, discectomy 0.87 mm, post-implantation 0.72 mm). While ROM for the hydrogel implant group was statistically unchanged compared to the intact disc, ROM for sham discs, which received a discectomy and no implant, was significant increase compared to intact. The compression and tension stiffness were decreased with discectomy and remained unchanged for both implant and sham groups, as expected because the annulus fibrosus was not repaired. Gross morphology images confirmed no ejection of NP implant. Conclusion An injectable implant that mimics non-degenerate NP has the potential to return motion segment ROM to normal subsequent to injury. PMID:22588378

Malhotra, Neil R.; Han, Woojin M.; Beckstein, Jesse; Cloyd, Jordan; Chen, Weiliam; Elliott, Dawn M.

2013-01-01

29

Glucosamine protects nucleus pulposus cells and induces autophagy via the mTOR-dependent pathway.  

PubMed

Although glucosamine has been suggested to be effective in the treatment of osteoarthritis, its effect on disc degeneration remains unclear. We sought to explore whether glucosamine can activate autophagy in rat nucleus pulposus (NP) cells and protect cells treated with IL-1? or hydrogen peroxide (H2 O2 ). Autophagy in cells was examined by detecting for LC3, Beclin-1, m-TOR, and p70S6K, as well as by analyzing autophagosomes. To inhibit autophagy, 3-methyladenine (3-MA) was used. In the cells treated with IL-1?, the levels of Adamts-4, Mmp-13, aggrecan, and Col2a1 were analyzed by real-time PCR and immunofluorescence. Apoptosis was analyzed by TUNEL. Cell senescence under H2 O2 was revealed by SA-?-Gal staining. Glucosamine could activate autophagy in a dose-dependent manner within 24?h and inhibit the phosphorylation of m-TOR and p70S6K. Autophagy in IL-1? or H2 O2 -treated cells was increased by glucosamine. Glucosamine attenuated the decrease of aggrecan and prevented the apoptosis of the NP cells induced by IL-1?, whereas 3-MA partly reversed these effects. The percentage of SA-?-Gal-positive cells induced by H2 O2 treatment was decreased by glucosamine, accompanied by the decline of p70S6K phosphorylation. Glucosamine protects NP cells and up-regulates autophagy by inhibiting the m-TOR pathway, which might point a potential therapeutic agent for disc degeneration. PMID:25087910

Jiang, LiBo; Jin, YongLong; Wang, HuiRen; Jiang, YunQi; Dong, Jian

2014-11-01

30

Expression of soluble Fas and soluble FasL in human nucleus pulposus cells  

PubMed Central

The study aimed for addressing the expression of soluble Fas (sFas) and soluble Fas Ligand (sFasL) in human nucleus pulposus (NP) and its attendant relationship with disc degeneration. Human NP samples were collected from patients with disc degeneration and cadavers as degenerate and normal groups, respectively. Subsequently, NP cells were cultured in monolayer. ELISA was performed to identify the expression levels of sFas and sFasL in the supernatant of NP cell cultures in vitro. Quantitative real-time PCR was used to detect the expression of sFas and sFasL in human NP cells in mRNA solution. The study comprised 12 degenerate and 8 normal cadaveric NP samples. The concentration value of sFas in the supernatant was significantly higher from degenerate NP than that from normal NP at each time point. In contrast, sFasL was significantly lower at each time point. Moreover, the expression of sFas and sFasL reached the peak at various early stages of cell cultures and decreased thereafter. Furthermore, the mRNA level of Fas in degenerate NP cells was significantly higher than that in normal cells; whereas FasL showed an opposite pattern. The study is the first addressing the expression of sFas and sFasL in human NP cell cultures. Moreover, the expression of sFas and sFasL varies with culture time in vitro with different levels in degenerate and normal settings. These findings indicate that sFas and sFasL might play a role in intervertebral disc degeneration. PMID:23923075

Sun, Zhen; Wan, Zhong-Yuan; Liu, Zhi-Heng; Guo, Yun-Shan; Yin, Jun-Bin; Duan, Chun-Guang; Gao, Yang; Li, Tao; Wang, Hai-Qiang; Luo, Zhuo-Jing

2013-01-01

31

Changes in the Molecular Phenotype of Nucleus Pulposus Cells with Intervertebral Disc Aging  

PubMed Central

Intervertebral disc (IVD) disorder and age-related degeneration are believed to contribute to low back pain. Cell-based therapies represent a promising strategy to treat disc degeneration; however, the cellular and molecular characteristics of disc cells during IVD maturation and aging still remain poorly defined. This study investigated novel molecular markers and their age-related changes in the rat IVD. Affymetrix cDNA microarray analysis was conducted to identify a new set of genes characterizing immature nucleus pulposus (NP) cells. Among these markers, select neuronal-related proteins (Basp1, Ncdn and Nrp-1), transcriptional factor (Brachyury T), and cell surface receptors (CD24, CD90, CD155 and CD221) were confirmed by real-time PCR and immunohistochemical (IHC) staining for differential expression between IVD tissue regions and among various ages (1, 12 and 21 months). NP cells generally possessed higher levels of mRNA or protein expression for all aforementioned markers, with the exception of CD90 in anulus fibrosus (AF) cells. In addition, CD protein (CD24 and CD90) and Brachyury (T) expression in immature disc cells were also confirmed via flow cytometry. Similar to IHC staining, results revealed a higher percentage of immature NP cells expressing CD24 and Brachyury, while higher percentage of immature AF cells was stained positively for CD90. Altogether, this study identifies that tissue-specific gene expression and age-related differential expression of the above markers do exist in immature and aged disc cells. These age-related phenotype changes provide a new insight for a molecular profile that may be used to characterize NP cells for developing cell-based regenerative therapy for IVD regeneration. PMID:23284858

Tang, Xinyan; Jing, Liufang; Chen, Jun

2012-01-01

32

Novel immortal human cell lines reveal subpopulations in the nucleus pulposus  

PubMed Central

Introduction Relatively little is known about cellular subpopulations in the mature nucleus pulposus (NP). Detailed understanding of the ontogenetic, cellular and molecular characteristics of functional intervertebral disc (IVD) cell populations is pivotal to the successful development of cell replacement therapies and IVD regeneration. In this study, we aimed to investigate whether phenotypically distinct clonal cell lines representing different subpopulations in the human NP could be generated using immortalization strategies. Methods Nondegenerate healthy disc material (age range, 8 to 15 years) was obtained as surplus surgical material. Early passage NP monolayer cell cultures were initially characterized using a recently established NP marker set. NP cells were immortalized by simian virus 40 large T antigen (SV40LTag) and human telomerase reverse transcriptase expression. Immortalized cells were clonally expanded and characterized based on collagen type I, collagen type II, ?1 (COL2A1), and SRY-box 9 (SOX9) protein expression profiles, as well as on expression of a subset of established in vivo NP cell lineage markers. Results A total of 54 immortal clones were generated. Profiling of a set of novel NP markers (CD24, CA12, PAX1, PTN, FOXF1 and KRT19 mRNA) in a representative set of subclones substantiated successful immortalization of multiple cellular subpopulations from primary isolates and confirmed their NP origin and/or phenotype. We were able to identify two predominant clonal NP subtypes based on their morphological characteristics and their ability to induce SOX9 and COL2A1 under conventional differentiation conditions. In addition, cluster of differentiation 24 (CD24)–negative NP responder clones formed spheroid structures in various culture systems, suggesting the preservation of a more immature phenotype compared to CD24-positive nonresponder clones. Conclusions Here we report the generation of clonal NP cell lines from nondegenerate human IVD tissue and present a detailed characterization of NP cellular subpopulations. Differential cell surface marker expression and divergent responses to differentiation conditions suggest that the NP subtypes may correspond to distinct maturation stages and represent distinct NP cell subpopulations. Hence, we provide evidence that the immortalization strategy that we applied is capable of detecting cell heterogeneity in the NP. Our cell lines yield novel insights into NP biology and provide promising new tools for studies of IVD development, cell function and disease. PMID:24972717

2014-01-01

33

Regeneration of nucleus pulposus tissue in an ovine intervertebral disc degeneration model by cell-free resorbable polymer scaffolds.  

PubMed

Degeneration of intervertebral discs (IVDs) occurs frequently and is often associated with lower back pain. Recent treatment options are limited and treat the symptoms rather than regenerate the degenerated disc. Cell-free, freeze-dried resorbable polyglycolic acid (PGA)-hyaluronan implants were used in an ovine IVD degeneration model. The nucleus pulposus of the IVD was partially removed, endoscopically. PGA-hyaluronan implants were immersed in autologous sheep serum and implanted into the disc defect. Animals with nucleotomy only served as controls. The T2-weighted/fat suppression sequence signal intensity index of the operated discs, as assessed by magnetic resonance imaging (MRI), showed that implantation of the PGA-hyaluronan implant improved (p?=?0.0066) the MRI signal compared to controls at 6?months after surgery. Histological analysis by haematoxylin and eosin and safranin O staining showed the ingrowth of cells with typical chondrocytic morphology, even cell distribution, and extracellular matrix rich in proteoglycan. Histomorphometric analyses confirmed that the implantation of the PGA-hyaluronan scaffolds improved (p?=?0.027) the formation of regenerated tissue after nucleotomy. Disc heights remained stable in discs with nucleotomy only as well as after implantation of the implant. In conclusion, implantation of cell-free polymer-based implants after nucleotomy induces nucleus pulposus tissue regeneration and improves disc water content in the ovine model. Copyright © 2012 John Wiley & Sons, Ltd. PMID:22865642

Woiciechowsky, Christian; Abbushi, Alexander; Zenclussen, Maria L; Casalis, Pablo; Krüger, Jan Philipp; Freymann, Undine; Endres, Michaela; Kaps, Christian

2014-10-01

34

Up-Regulation of Pain Behavior and Glial Activity in the Spinal Cord after Compression and Application of Nucleus Pulposus onto the Sciatic Nerve in Rats  

PubMed Central

Study Design Experimental animal study. Purpose To evaluate pain-related behavior and changes in glial activity in the spinal dorsal horn after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. Overview of Literature Mechanical compression and inflammation caused by prostaglandins and cytokines at disc herniation sites induce pain. Structural changes and pain-associated cytokines in the dorsal root ganglia and spinal dorsal horn contribute to prolonged pain. Glial cells in the spinal dorsal horn may also function in pain transmission. Methods The sciatic nerve was compressed with NP for 2 seconds using forceps in the NP+nerve compression group; the sham-operated group received neither compression nor NP; and the control group received no operation. Mechanical hyperalgesia was measured for 3 weeks using von Frey filaments. Glial activity in the spinal dorsal horn was examined 7 days and 14 days postsurgery using anti-glial fibrillary acidic protein and anti-Ionized calcium binding adaptor molecule-1 antibodies to detect astrocytes and microglia, respectively. Results Mechanical hyperalgesia was detected throughout the 14-day observation in the NP+nerve compression group, but not in control or sham-operated groups (p<0.05). Both astrocytes and microglia were significantly increased in the spinal dorsal horn of the NP+nerve compression group compared to control and sham groups on days 7 and 14 (p<0.05). Conclusions Nerve compression with NP application produces pain-related behavior, and up-regulates astrocytes and microglia in the spinal dorsal horn, suggesting that these glia may be related to pain transmission. PMID:25346806

Norimoto, Masaki; Sakuma, Yoshihiro; Suzuki, Miyako; Orita, Sumihisa; Yamauchi, Kazuyo; Inoue, Gen; Aoki, Yasuchika; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Kubota, Gou; Oikawa, Yasuhiro; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Nakamura, Junichi; Toyone, Tomoaki; Takahashi, Kazuhisa

2014-01-01

35

PKC? Signalling Activates ERK1/2, and Regulates Aggrecan, ADAMTS5, and miR377 Gene Expression in Human Nucleus Pulposus Cells  

PubMed Central

The protein kinase C (PKC) signaling, a major regulator of chondrocytic differentiation, has been also implicated in pathological extracellular matrix remodeling, and here we investigate the mechanism of PKC?-dependent regulation of the chondrocytic phenotype in human nucleus pulposus (NP) cells derived from herniated disks. NP cells from each donor were successfully propagated for 25+ culture passages, with remarkable tolerance to repeated freeze-and-thaw cycles throughout long-term culturing. More specifically, after an initial downregulation of COL2A1, a stable chondrocytic phenotype was attested by the levels of mRNA expression for aggrecan, biglycan, fibromodulin, and lumican, while higher expression of SOX-trio and Patched-1 witnessed further differentiation potential. NP cells in culture also exhibited a stable molecular profile of PKC isoforms: throughout patient samples and passages, mRNAs for PKC ?, ?, ?, ?, ?, ?, and µ were steadily detected, whereas ?, ?, and ? were not. Focusing on the signalling of PKC?, an isoform that may confer protection against degeneration, we found that activation with the PKC?-specific activator small peptide ??RACK led sequentially to a prolonged activation of ERK1/2, increased abundance of the early gene products ATF, CREB1, and Fos with concurrent silencing of transcription for Ki67, and increases in mRNA expression for aggrecan. More importantly, ??RACK induced upregulation of hsa-miR-377 expression, coupled to decreases in ADAMTS5 and cleaved aggrecan. Therefore, PKC? activation in late passage NP cells may represent a molecular basis for aggrecan availability, as part of an PKC?/ERK/CREB/AP-1-dependent transcriptional program that includes upregulation of both chondrogenic genes and microRNAs. Moreover, this pathway should be considered as a target for understanding the molecular mechanism of IVD degeneration and for therapeutic restoration of degenerated disks. PMID:24312401

Pneumaticos, Spiros G.; Tragas, Adamantios A.; Michalopoulos, Ioannis; Mangoura, Dimitra

2013-01-01

36

Osthole, a herbal compound, alleviates nucleus pulposus-evoked nociceptive responses through the suppression of overexpression of acid-sensing ion channel 3 (ASIC3) in rat dorsal root ganglion  

PubMed Central

Summary Background Osthole (Ost), a natural coumarin derivative, has been shown to inhibit many pro-inflammatory mediators and block voltage-gated Na+ channels. During inflammation, acidosis is an important pain inducer which activates nociceptors by gating depolarizing cationic channels, such as acid-sensing ion channel 3 (ASIC3). The aim of this study was to examine the effects of Ost on nucleus pulposus-evoked nociceptive responses and ASIC3 over-expression in the rat dorsal root ganglion, and to investigate the possible mechanism. Material/Methods Radicular pain was generated with application of nucleus pulposus (NP) to nerve root. Mechanical allodynia was evaluated using von Frey filaments with logarithmically incremental rigidity to calculate the 50% probability thresholds for mechanical paw withdrawal. ASIC3 protein expression in dorsal root ganglions (DRGs) was assessed with Western blot and immunohistochemistry. Membrane potential (MP) shift of DRG neurons induced by ASIC3-sensitive acid (pH6.5) was determined by DiBAC4 (3) fluorescence intensity (F.I.). Results The NP-evoked mechanical hyperalgesia model showed allodynia for 3 weeks, and ASIC3 expression was up-regulated in DRG neurons, reaching peak on Day 7. Epidural administration of Ost induced a remarkable and prolonged antinociceptive effect, accompanied by an inhibition of over-expressed ASIC3 protein and of abnormal shift of MP. Amiloride (Ami), an antagonist of ASIC3, strengthened the antinociceptive effect of Ost. Conclusions Up-regulation of ASIC3 expression may be associated with NP-evoked mechanical hyperalgesia. A single epidural injection of Ost decreased ASIC3 expression in DGR neurons and the pain in the NP-evoked mechanical hyperalgesia model. Osthole may be of great benefit for preventing chronic pain status often seen in lumbar disc herniation (LDH). PMID:22648244

He, Qiu-Lan; Chen, Yuling; Qin, Jian; Mo, Sui-Lin; Wei, Ming; Zhang, Jin-Jun; Li, Mei-Na; Zou, Xue-Nong; Zhou, Shu-Feng; Chen, Xiao-Wu; Sun, Lai-Bao

2012-01-01

37

Posterior thecal lumbar disc herniation mimicking synovial cyst  

Microsoft Academic Search

We describe a 70 year-old-patient with a rare, misleading presentation of lumbar disc prolapse, which on CT mimicked a synovial cyst. The whole nucleus pulposus had herniated, become sequestrated, and migrated behind the theca adjacent to the L4–5 facet joint. There was no continuity of the disc material with the intervertebral space. A fenestration was performed and the sequestrated disc

D. E. Sakas; M. A. Farrell; S. Young; J. Toland

1995-01-01

38

Posterior thecal lumbar disc herniation mimicking synovial cyst  

Microsoft Academic Search

We describe a 70 year-old-patient with a rare, misleading presentation of lumbar disc prolapse, which on CT mimicked a synovial cyst. The whole nucleus pulposus had herniated, become sequestrated, and migrated behind the theca adjacent to the L4-5 facet joint. There was no continuity of the disc material with the intervertebral space. A fenestration was performed and the sequestrated disc

D. E. Sakas; M. A. Farrell; S. Young; J. Toland

1995-01-01

39

Influence of different commercial scaffolds on the in vitro differentiation of human mesenchymal stem cells to nucleus pulposus-like cells  

Microsoft Academic Search

Introduction  Cell-based therapies for regeneration of the degenerated intervertebral disc (IVD) are an alternative to current surgical\\u000a intervention. Mesenchymal stem cells (MSCs), in combination with a scaffold, might be ideal candidates for regenerating nucleus\\u000a pulposus (NP), the pressure-distributing part of the IVD. While the use of growth factors for MSCs differentiation currently\\u000a receives major attention, in this study we compare the

Alessandro Bertolo; Marco Mehr; Niklaus Aebli; Martin Baur; Stephen J. Ferguson; Jivko V. Stoyanov

40

Reconstruction of an In Vitro Niche for the Transition from Intervertebral Disc Development to Nucleus Pulposus Regeneration  

PubMed Central

The nucleus pulposus (NP) plays a prominent role in both the onset and progression of intervertebral disc degeneration. While autologous repair strategies have demonstrated some success, their in vitro culture system is outdated and insufficient for maintaining optimally functioning cells through the required extensive passaging. Consequently, the final population of cells may be unsuitable for the overwhelming task of repairing tissue in vivo and could result in subpar clinical outcomes. Recent work has identified synovium-derived stem cells (SDSCs) as a potentially important new candidate. This population of precursors can promote matrix regeneration and additionally restore the balance of catabolic and anabolic metabolism of surrounding cells. Another promising application is their ability to produce an extracellular matrix in vitro that can be modified via decellularization to produce a tissue-specific substrate for efficient cell expansion, while retaining chondrogenic potential. When combined with hypoxia, soluble factors, and other environmental regulators, the resultant complex microenvironment will more closely resemble the in vivo niche, which further improves the cell capacity, even after extensive passaging. In this review, the adaptive mechanisms NP cells utilize in vivo are considered for insight into what factors are important for constructing a tissue-specific in vitro niche. Evidence for the use of SDSCs for NP regeneration is also discussed. Many aspects of NP behavior are still unknown, which could lead to future work yielding key information on producing sufficient numbers of a high-quality NP-specific population that is able to regenerate deteriorated NP in vivo. PMID:23259403

Shoukry, Mark; Li, Jingting

2013-01-01

41

Integrin-Mediated Interactions with Extracellular Matrix Proteins for Nucleus Pulposus Cells of the Human Intervertebral Disc  

PubMed Central

The extracellular matrix (ECM) of the human intervertebral disc is rich in molecules that interact with cells through integrin-mediated attachments. Porcine nucleus pulposus (NP) cells have been shown to interact with laminin (LM) isoforms LM-111 and LM-511 through select integrins that regulate biosynthesis and cell attachment. Since human NP cells lose many phenotypic characteristics with age, attachment and interaction with the ECM may be altered. Expression of LM-binding integrins was quantified for human NP cells using flow cytometry. The cell-ECM attachment mechanism was determined by quantifying cell attachment to LM-111, LM-511, or type II collagen after functionally blocking specific integrin subunits. Human NP cells express integrins ?1, ?3, and ?5, with over 70% of cells positive for each subunit. Blocking subunit ?1 inhibited NP cell attachment to all substrates. Blocking subunits ?1, ?2, ?3 and ?5 simultaneously, but not individually, inhibits NP cell attachment to laminins. While integrin ?6?1 mediated porcine NP cell attachment to LM-111, we found integrins ?3, ?5, and ?1 instead contributed to human NP cell attachment. These findings identify integrin subunits that may mediate interactions with the ECM for human NP cells and could be used to promote cell attachment, survival and biosynthesis in cell-based therapeutics. PMID:23737292

Bridgen, D.T.; Gilchrist, C.L.; Richardson, W.J.; Isaacs, R.E.; Brown, C.R.; Yang, K.L.; Chen, J.; Setton, L.A.

2013-01-01

42

Variations in Gene and Protein Expression in Canine Chondrodystrophic Nucleus Pulposus Cells following Long-Term Three-Dimensional Culture  

PubMed Central

Intervertebral disc (IVD) degeneration greatly affects quality of life. The nucleus pulposus (NP) of chondrodystrophic dog breeds (CDBs) is similar to the human NP, because the cells disappear with age and are replaced by fibrochondrocyte-like cells. However, because IVD develops as early as within the first year of life, we used canines as a model to investigate in vitro the mechanisms underlying IVD degeneration. Specifically, we evaluated the potential of a three-dimensional (3D) culture of healthy NP as an in vitro model system to investigate the mechanisms of IVD degeneration. Agarose hydrogels were populated with healthy NP cells from beagles after performing magnetic resonance imaging, and mRNA expression profiles and pericellular extracellular matrix (ECM) protein distribution were determined. After 25 days of 3D culture, there was a tendency for redifferentiation into the native NP phenotype, and mRNA levels of Col2A1, COMP, and CK18 were not significantly different from those of freshly isolated cells. Our findings suggest that long-term 3D culture promoted chondrodystrophic NP redifferentiation through reconstruction of the pericellular microenvironment. Further, lipopolysaccharide (LPS) induced expression of TNF-?, MMP3, MMP13, VEGF, and PGES mRNA in the 3D cultures, creating a molecular milieu that mimics that of degenerated NP. These results suggest that this in vitro model represents a reliable and cost-effective tool for evaluating new therapies for disc degeneration. PMID:23658803

Iwata, Munetaka; Ochi, Hiroki; Asou, Yoshinori; Haro, Hirotaka; Aikawa, Takeshi; Harada, Yasuji; Nezu, Yoshinori; Yogo, Takuya; Tagawa, Masahiro; Hara, Yasushi

2013-01-01

43

A new non-enzymatic method for isolating human intervertebral disc cells preserves the phenotype of nucleus pulposus cells.  

PubMed

Cells isolated from intervertebral disc (IVD) tissues of human surgical samples are one of potential sources for the IVD cellular therapy. The purpose of this study was to develop a new non-enzymatic method, "tissue incubation", for isolating human IVD cells. The IVD tissues of annulus fibrosus (AF) and nucleus pulposus (NP) were incubated separately in tissue culture flasks with culture medium. After 7-10 days incubation, cells were able to migrate out of IVD tissues and proliferate in vitro. After 3-4 weeks culture, expanded cells were harvested by trypsinization, and the remaining tissues were transferred to a new flask for another round of incubation. The molecular phenotype of IVD cells from juvenile and adult human samples was evaluated by both flow cytometry analysis and immunocytochemical staining for the expression of protein markers of NP cells (CD24, CD54, CD239, integrin ?6 and laminin ?5). Flow cytometry confirmed that both AF and NP cells of all ages positively expressed CD54 and integrin ?6, with higher expression levels in NP cells than in AF cells for the juvenile group sample. However, CD24 expression was only found in juvenile NP cells, and not in AF or older disc cells. Similar expression patterns for NP markers were also confirmed by immunocytochemistry. In summary, this new non-enzymatic tissue incubation method for cell isolation preserves molecular phenotypic markers of NP cells and may provide a valuable cell source for the study of NP regeneration strategies. PMID:24101443

Tang, Xinyan; Richardson, William J; Fitch, Robert D; Brown, Christopher R; Isaacs, Robert E; Chen, Jun

2014-12-01

44

Loss of HIF-1? in the Notochord Results in Cell Death and Complete Disappearance of the Nucleus Pulposus  

PubMed Central

The intervertebral disc (IVD) is one of the largest avascular organs in vertebrates. The nucleus pulposus (NP), a highly hydrated and proteoglycan-enriched tissue, forms the inner portion of the IVD. The NP is surrounded by a multi-lamellar fibrocartilaginous structure, the annulus fibrosus (AF). This structure is covered superior and inferior side by cartilaginous endplates (CEP). The NP is a unique tissue within the IVD as it results from the differentiation of notochordal cells, whereas, AF and CEP derive from the sclerotome. The hypoxia inducible factor-1? (HIF-1?) is expressed in NP cells but its function in NP development and homeostasis is largely unknown. We thus conditionally deleted HIF-1? in notochordal cells and investigated how loss of this transcription factor impacts NP formation and homeostasis at E15.5, birth, 1 and 4 months of age, respectively. Histological analysis, cell lineage studies, and TUNEL assay were performed. Morphologic changes of the mutant NP cells were identified as early as E15.5, followed, postnatally, by the progressive disappearance and replacement of the NP with a novel tissue that resembles fibrocartilage. Notably, lineage studies and TUNEL assay unequivocally proved that NP cells did not transdifferentiate into chondrocyte-like cells but they rather underwent massive cell death, and were completely replaced by a cell population belonging to a lineage distinct from the notochordal one. Finally, to evaluate the functional consequences of HIF-1? deletion in the NP, biomechanical testing of mutant IVD was performed. Loss of the NP in mutant mice significantly reduced the IVD biomechanical properties by decreasing its ability to absorb mechanical stress. These findings are similar to the changes usually observed during human IVD degeneration. Our study thus demonstrates that HIF-1? is essential for NP development and homeostasis, and it raises the intriguing possibility that this transcription factor could be involved in IVD degeneration in humans. PMID:25338007

Robling, Alexander; Wilson, Tremika LeShan; Giaccia, Amato J.; Shapiro, Irving M.; Schipani, Ernestina; Risbud, Makarand V.

2014-01-01

45

Notochordal cells protect nucleus pulposus cells from degradation and apoptosis: implications for the mechanisms of intervertebral disc degeneration  

PubMed Central

Introduction The relative resistance of non-chondrodystrophic (NCD) canines to degenerative disc disease (DDD) may be due to a combination of anabolic and anti-catabolic factors secreted by notochordal cells within the intervertebral disc (IVD) nucleus pulposus (NP). Factors known to induce DDD include interleukin-1 beta (IL-1ß) and/or Fas-Ligand (Fas-L). Therefore we evaluated the ability of notochordal cell conditioned medium (NCCM) to protect NP cells from IL-1ß and IL-1ß +FasL-mediated cell death and degeneration. Methods We cultured bovine NP cells with IL-1ß or IL-1ß+FasL under hypoxic serum-free conditions (3.5% O2) and treated the cells with either serum-free NCCM or basal medium (Advanced DMEM/F-12). We used flow cytometry to evaluate cell death and real-time (RT-)PCR to determine the gene expression of aggrecan, collagen 2, and link protein, mediators of matrix degradation ADAMTS-4 and MMP3, the matrix protection molecule TIMP1, the cluster of differentiation (CD)44 receptor, the inflammatory cytokine IL-6 and Ank. We then determined the expression of specific apoptotic pathways in bovine NP cells by characterizing the expression of activated caspases-3, -8 and -9 in the presence of IL-1ß+FasL when cultured with NCCM, conditioned medium obtained using bovine NP cells (BCCM), and basal medium all supplemented with 2% FBS. Results NCCM inhibits bovine NP cell death and apoptosis via suppression of activated caspase-9 and caspase-3/7. Furthermore, NCCM protects NP cells from the degradative effects of IL-1ß and IL-1ß+Fas-L by up-regulating the expression of anabolic/matrix protective genes (aggrecan, collagen type 2, CD44, link protein and TIMP-1) and down-regulating matrix degrading genes such as MMP-3. Expression of ADAMTS-4, which encodes a protein for aggrecan remodeling, is increased. NCCM also protects against IL-1+FasL-mediated down-regulation of Ank expression. Furthermore, NP cells treated with NCCM in the presence of IL-1ß+Fas-L down-regulate the expression of IL-6 by almost 50%. BCCM does not mediate cell death/apoptosis in target bovine NP cells. Conclusions Notochordal cell-secreted factors suppress NP cell death by inhibition of activated caspase-9 and -3/7 activity and by up-regulating genes contributing anabolic activity and matrix protection of the IVD NP. Harnessing the restorative powers of the notochordal cell could lead to novel cellular and molecular strategies in the treatment of DDD. PMID:22206702

2011-01-01

46

Evaluation of Behavior and Expression of Receptor Activator of Nuclear Factor-Kappa B Ligand in Dorsal Root Ganglia after Sciatic Nerve Compression and Application of Nucleus Pulposus in Rats  

PubMed Central

Study Design Experimental animal study. Purpose To evaluate pain-related behavior and changes in nuclear factor-kappa B (NF-kB), receptor activator of NF-kB (RANK), and ligand (RANKL) in dorsal root ganglia (DRG) after combined sciatic nerve compression and nucleus pulposus (NP) application in rats. Overview of Literature The pathological mechanisms underlying pain from lumbar-disc herniation have not been fully elucidated. RANKL are transcriptional regulators of inflammatory cytokines. Our aim was to evaluate pain-related behavior and RANKL expression in DRG after sciatic-nerve compression and application of NP in rats. Methods Mechanical hyperalgesia and RANKL expression were assessed in three groups of rats: NP+sciatic nerve compression (2 seconds), sham-operated, and controls (n=20 each). Mechanical hyperalgesia was measured every other day for 3 weeks using von Frey filaments. RANKL expression in L5 DRGs was examined at five and ten days after surgery using immunohistochemistry. Results Mechanical hyperalgesia was observed over the 12-day observation period in the NP+nerve compression group, but not in the control and sham-operated animal groups (p<0.05). RANKL immunoreactivity was seen in the nuclei of L5 DRG neurons, and its expression was significantly upregulated in NP+nerve compression rats compared with control and sham-operated rats (p<0.01). Conclusions The exposure of sciatic nerves to mechanical compression and NP produces pain-related behavior and up-regulation of RANKL in DRG neurons. RANKL may play an important role in mediating pain after sciatic nerve injury with exposure to NP.

Matsuyama, Yoshiyuki; Sakuma, Yoshihiro; Suzuki, Miyako; Orita, Sumihisa; Yamauchi, Kazuyo; Inoue, Gen; Aoki, Yasuchika; Ishikawa, Tetsuhiro; Miyagi, Masayuki; Kamoda, Hiroto; Kubota, Gou; Oikawa, Yasuhiro; Inage, Kazuhide; Sainoh, Takeshi; Sato, Jun; Nakamura, Junichi; Toyone, Tomoaki; Takahashi, Kazuhisa

2014-01-01

47

Tonicity enhancer binding protein (TonEBP) and hypoxia-inducible factor (HIF) coordinate heat shock protein 70 (Hsp70) expression in hypoxic nucleus pulposus cells: role of Hsp70 in HIF-1? degradation.  

PubMed

The objective of our study was to examine the regulation of hypoxic expression of heat shock protein 70 (Hsp70) in nucleus pulposus cells and to determine if Hsp70 promoted hypoxia-inducible factor (HIF)-1? degradation. Rat nucleus pulposus cells were maintained in culture in either 21% or 1% oxygen. To determine the regulation of Hsp70 expression by tonicity enhancer binding protein (TonEBP) and HIF-1/2, loss-of-function and gain-of-function experiments and mutational analysis of the Hsp70 promoter were performed. Hypoxia increased Hsp70 expression in nucleus pulposus cells. Noteworthy, hypoxia increased TonEBP transactivation and mutation of TonE motifs blocked hypoxic induction of the Hsp70 promoter. In contrast, mutation of hypoxia response element (HRE) motifs coupled with loss-of-function experiments suggested that HIF-1 and HIF-2 suppressed Hsp70 promoter activity and transcription. Interestingly, HIF-? interferes with TonEBP function and suppresses the inductive effect of TonEBP on the Hsp70 promoter. In terms of Hsp70 function, when treated with Hsp70 transcriptional inhibitor, KNK437, there was an increase in HIF-1? protein stability and transcriptional activity. Likewise, when Hsp70 was overexpressed, the stability of HIF-1? and its transcriptional activity decreased. Hsp70 interacted with HIF-1? under hypoxic conditions and evidenced increased binding when treated with MG132, a proteasomal inhibitor. These results suggest that Hsp70 may promote HIF-1? degradation through the proteasomal pathway in nucleus pulposus cells. In hypoxic and hyperosmolar nucleus pulposus cells, Hsp70, TonEBP, and HIFs form a regulatory loop. We propose that the positive regulation by TonEBP and negative regulation of Hsp70 by HIF-1 and HIF-2 may serve to maintain Hsp70 levels in these cells, whereas Hsp70 may function in controlling HIF-1? homeostasis. PMID:22322648

Gogate, Shilpa S; Fujita, Nobuyuki; Skubutyte, Renata; Shapiro, Irving M; Risbud, Makarand V

2012-05-01

48

The catabolic effect of TNF? on bovine nucleus pulposus intervertebral disc cells and the restraining role of glucosamine sulfate in the TNF?-mediated up-regulation of MMP-3.  

PubMed

Glucosamine is an endogenous amino monosaccharide naturally occurring in the cartilage. We have recently shown that glucosamine sulfate promotes the biosynthesis of glycosaminoglycans in intervertebral disc cells. Here we assessed the role of glucosamine sulfate in the response of bovine nucleus pulposus cell monolayers to TNF? that constitutes an early signal of disc degeneration. TNF? was not found to affect nucleus pulposus cells' viability, while it resulted in a ?2.5-fold increase of the intracellular ROS levels, a rapid transient phosphorylation of p38 MAPK and a ROS-dependent activation of JNKs. In addition, TNF? had a prominent inflammatory effect on nucleus pulposus cells by up-regulating MMP-3 expression that was reversed when inhibiting the kinase activity of p38 MAPK. Glucosamine sulfate also diminished the increased by TNF? MMP-3 mRNA levels, but this was unrelated to the p38 MAPK or ROS-mediated JNK activation. Even though the mode of action of glucosamine towards TNF? remains to be elucidated, to the best of our knowledge, this is the first report providing evidence for the protective role of glucosamine against this early mediator of disc degeneration that could support the potential usage of this molecule as a treatment for preventing disc degenerative disorders. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1701-1707, 2014. PMID:25220975

Mavrogonatou, Eleni; Angelopoulou, Maria T; Kletsas, Dimitris

2014-12-01

49

Levofloxacin increases the effect of serum deprivation on anoikis of rat nucleus pulposus cells via Bax/Bcl-2/caspase-3 pathway.  

PubMed

Abstract Levofloxacin, a fluoroquinolone, is a widely-used and effective antibiotic. However, various adverse side effects are associated with levofloxacin. The purpose of this study was to further explore the effects of levofloxacin on rat nucleus pulposus cells (NPCs). Inverted phase-contrast microscopy, flow cytometry and caspase-3 activity assays were used and revealed that serum deprivation induced apoptosis, which was markedly increased by levofloxacin in a dose-dependent manner. Simultaneously, levofloxacin decreased cell binding to type II collagen (COL2). Thus, levofloxacin-induced apoptosis exhibits characteristics of anoikis, the process by which cell death is triggered by separation from the extracellular matrix, which contains COL2. Furthermore, real-time quantitative RT-PCR was used to further confirm that levofloxacin downregulates COL2 expression in a dose-dependent manner. At last, western blot was used to find that levofloxacin increased the ratio of Bax/Bcl-2 and active caspase-3 in a dose-dependent manner. Levofloxacin therefore increases the effects of serum deprivation on anoikis by downregulating COL2 in rat NPCs in vitro via Bax/Bcl-2/caspase-3 pathway. This research provides a novel insight into the mechanisms of levofloxacin-induced toxicity and may potentially lead to a better understanding of the clinical effects of levofloxacin, especially in terms of intervertebral disc degeneration. PMID:25224805

Yang, Si-Dong; Bai, Zhi-Long; Zhang, Feng; Ma, Lei; Yang, Da-Long; Ding, Wen-Yuan

2014-12-01

50

FasL on human nucleus pulposus cells prevents angiogenesis in the disc by inducing Fas-mediated apoptosis of vascular endothelial cells  

PubMed Central

The intervertebral disc is the largest avascular organ in the human body. However, with the progress of intervertebral disc degeneration (IDD), the disc tends to be vascularized increasingly via angiogenesis. It is well established that both human nucleus pulposus (NP) cells and vascular endothelial cells express FasL and Fas. However, the issue remains open as to whether there are certain active mechanisms preventing angiogenesis in the disc via the FasL-Fas machinery. Here, we established a co-culture system of human NP cells and vascular endothelial (HMEC-1) cells. We found that normal NP cells were more capable of inducing apoptosis in HMEC-1 cells (14.2±3.4%) than degenerate NP cells (6.7±1.9%), p<0.05. By up-regulating the FasL expression in degenerate NP cells, we found that FasL played an essential role in the mediation of HMEC-1 cell apoptosis with the activation of downstream FADD and caspase-3. Furthermore, we found an increased Fas expression in HMEC-1 cells following co-cultured with NP cells, which might be closely linked with FasL produced by NP cells and enhance their interaction. Collectively, this is the first study showing FasL-Fas network might plays an important role in the molecular mechanisms of angiogenesis avoidance of human disc. Consequently, our findings might shed light on the pathogenesis in human IDD and provide a novel target for the treatment strategies for IDD. PMID:24228099

Sun, Zhen; Wan, Zhong-Yuan; Guo, Yun-Shan; Wang, Hai-Qiang; Luo, Zhuo-Jing

2013-01-01

51

Effect of Cryopreservation on Canine and Human Activated Nucleus Pulposus Cells: A Feasibility Study for Cell Therapy of the Intervertebral Disc  

PubMed Central

Abstract It has been shown that coculture of bone marrow–derived stromal cells (BMSCs) with intervertebral disc (IVD) nucleus pulposus (NP) cells significantly activates the biological characteristics of NP cells in animal models and in humans. We therefore predicted that activated NP cells would be a useful graft source for cellular transplantation therapy in the treatment of degenerative IVDs. However, the activation protocol is based on fresh isolation and activation of NP cells, which limits the timing of clinical application. Cell transplantation therapy could be offered to more patients than is now possible if activated NP cells could be transplanted as and when required by the condition of the patient. No study has investigated the effect of cryopreservation on NP cells after enzymatic isolation. We investigated the effects of cryopreservation of canine and human NP cells in both cell and tissue form before coculture with autologous BMSCs. Cell viability, proliferation, glycosaminoglycan production, aggrecan transcriptional activity, colony generation, and gene expression profile of the cells after cryopreservation and subsequent coculture were analyzed. The influence of cryopreservation on cell chromosomal abnormalities and tumorigenesis was also studied. The results showed that there were no clear differences between the noncryopreserved and cryopreserved cells in terms of cell viability, proliferation capacity, and capacity to synthesize extracellular matrix. Furthermore, the cells showed no apparent chromosomal abnormalities or tumorigenic ability and exhibited similar patterns of gene expression. These findings suggest that by using cryopreservation, it may be possible to transplant activated NP cells upon request for patients' needs. PMID:23914334

Tanaka, Masahiro; Hiyama, Akihiko; Arai, Fumiyuki; Nakajima, Daisuke; Nukaga, Tadashi; Nakai, Tomoko; Mochida, Joji

2013-01-01

52

Development and initial characterization of a chemically stabilized elastin-glycosaminoglycan-collagen composite shape-memory hydrogel for nucleus pulposus regeneration.  

PubMed

Nucleus pulposus (NP) is a resilient and hydrophilic tissue which plays a significant role in the biomechanical function of the intervertebral disc (IVD). Destruction of the NP extracellular matrix (ECM) is observed during the early stages of IVD degeneration. Herein, we describe the development and initial characterization of a novel biomaterial which attempts to recreate the resilient and hydrophilic nature of the NP via the construction of a chemically stabilized elastin-glycosaminoglycan-collagen (EGC) composite hydrogel. Results demonstrated that a resilient, hydrophilic hydrogel which displays a unique "shape-memory" sponge characteristic could be formed from a blend of soluble elastin aggregates, chondroitin-6-sulfate, hyaluronic acid and collagen following freeze-drying, stabilization with a carbodiimide and penta-galloyl glucose-based fixative, and subsequent partial degradation with glycosaminoglycan degrading enzymes. The resultant material exhibited the ability to restore its original dimensions and water content following multi-cycle mechanical compression and illustrated resistance to accelerated enzymatic degradation. Preliminary in vitro studies utilizing human adipose derived stem cells (hADSCs) demonstrated that the material was cytocompatible and supported differentiation towards an NP cell-like phenotype. In vivo biocompatibility studies illustrated host cell infiltration and evidence of active remodeling following 4 weeks of implantation. Feasibility studies demonstrated that the EGC hydrogel could be delivered via minimally invasive methods. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 4380-4393, 2014. PMID:24497431

Mercuri, Jeremy; Addington, Caroline; Pascal, Richard; Gill, Sanjitpal; Simionescu, Dan

2014-12-01

53

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

54

Three-dimensional hypoxic culture of human mesenchymal stem cells encapsulated in a photocurable, biodegradable polymer hydrogel: a potential injectable cellular product for nucleus pulposus regeneration.  

PubMed

Nucleus pulposus (NP) tissue damage can induce detrimental mechanical stresses and strains on the intervertebral disc, leading to disc degeneration. This study demonstrates the potential of a novel, photo-curable, injectable, synthetic polymer hydrogel (pHEMA-co-APMA grafted with polyamidoamine (PAA)) to encapsulate and differentiate human mesenchymal stem cells (hMSC) towards a NP phenotype under hypoxic conditions which could be used to restore NP tissue function and mechanical properties. Encapsulated hMSC cultured in media (hMSC and chondrogenic) displayed good cell viability up to day 14. The genotoxicity effects of ultraviolet (UV) on hMSC activity confirmed the acceptability of 2.5min of UV light exposure to cells. Cytotoxicity investigations revealed that hMSC cultured in media containing p(HEMA-co-APMA) grafted with PAA degradation product (10% and 20%v/v concentration) for 14days significantly decreased the initial hMSC adhesion ability and proliferation rate from 24hrs to day 14. Successful differentiation of encapsulated hMSC within hydrogels towards chondrogenesis was observed with elevated expression levels of aggrecan and collagen II when cultured in chondrogenic media under hypoxic conditions, in comparison with culture in hMSC media for 14days. Characterization of the mechanical properties revealed a significant decrease in stiffness and modulus values of cellular hydrogels in comparison with acellular hydrogels at both day 7 and day 14. These results demonstrate the potential use of an in vivo photo-curable injectable, synthetic hydrogel with encapsulated hMSC for application in the repair and regeneration of NP tissue. PMID:24793656

Kumar, Deepak; Gerges, Irini; Tamplenizza, Margherita; Lenardi, Cristina; Forsyth, Nicholas R; Liu, Yang

2014-08-01

55

Functional nucleus pulposus-like matrix assembly by human mesenchymal stromal cells is directed by macromer concentration in photocrosslinked carboxymethylcellulose hydrogels.  

PubMed

Intervertebral disc (IVD) degeneration is associated with several pathophysiologic changes of the IVD, including dehydration of the nucleus pulposus (NP). Tissue engineering strategies may be used to restore both biological and mechanical function of the IVD following removal of NP tissue during surgical intervention. Recently, photocrosslinked carboxymethylcellulose (CMC) hydrogels were shown to support chondrogenic, NP-like extracellular matrix (ECM) elaboration by human mesenchymal stromal cells (hMSCs) when supplemented with TGF-?3; however, mechanical properties of these constructs did not reach native values. Fabrication parameters (i.e., composition, crosslinking density) can influence the bulk mechanical properties of hydrogel scaffolds, as well as cellular behavior and differentiation patterns. The objective of this study was to evaluate the influence of CMC macromer concentration (1.5, 2.5 and 3.5 % weight/volume) on bulk hydrogel properties and NP-like matrix elaboration by hMSCs. The lowest macromer concentration of 1.5 % exhibited the highest gene expression levels of aggrecan and collagen II at day 7, corresponding with the largest accumulation of glycosaminoglycans and collagen II by day 42. The ECM elaboration in the 1.5 % constructs was more homogeneously distributed compared to primarily pericellular localization in 3.5 % gels. The 1.5 % gels also displayed significant improvements in mechanical functionality by day 42 compared to earlier time points, which was not seen in the other groups. The effects of macromer concentration on matrix accumulation and organization are likely attributed to quantifiable differences in polymer crosslinking density and diffusive properties between the various hydrogel formulations. Taken together, these results demonstrate that macromer concentration of CMC hydrogels can direct hMSC matrix elaboration, such that a lower polymer concentration allows for greater NP-like ECM assembly and improvement of mechanical properties over time. PMID:25092545

Gupta, Michelle S; Nicoll, Steven B

2014-11-01

56

Inflammatory Cytokines Associated with Degenerative Disc Disease Control Aggrecanase-1 (ADAMTS-4) Expression in Nucleus Pulposus Cells through MAPK and NF-?B  

PubMed Central

We investigated TNF-? and IL-1? regulation of ADAMTS-4 expression in nucleus pulposus (NP) cells and its role in aggrecan degradation. Real-time quantitative RT-PCR, Western blotting, and transient transfections with rat NP cells and lentiviral silencing with human NP cells were performed to determine the roles of MAPK and NF-?B in cytokine-mediated ADAMTS-4 expression and function. ADAMTS4 expression and promoter activity increased in NP cells after TNF-? and IL-1? treatment. Treatment of cells with MAPK and NF-?B inhibitors abolished the inductive effect of the cytokines on ADAMTS4 mRNA and protein expression. Although ERK1, p38?, p38?2, and p38? were involved in induction, ERK2 and p38? played no role in TNF-?–dependent promoter activity. The inductive effect of p65 on ADAMTS4 promoter was confirmed through gain and loss-of-function studies. Cotransfection of p50 completely blocked p65-mediated induction. Lentiviral transduction with shRNA plasmids shp65, shp52, shIKK-?, and shIKK-? significantly decreased TNF-?–dependent increase in ADAMTS-4 and -5 levels and aggrecan degradation. Silencing of either ADAMTS-4 or -5 resulted in reduction in TNF-?–dependent aggrecan degradation in NP cells. By controlling activation of MAPK and NF-?B signaling, TNF-? and IL-1? modulate expression of ADAMTS-4 in NP cells. To our knowledge, this is the first study to show nonredundant contribution of both ADAMTS-4 and ADAMTS-5 to aggrecan degradation in human NP cells in vitro. PMID:23602832

Tian, Ye; Yuan, Wen; Fujita, Nobuyuki; Wang, Jianru; Wang, Hua; Shapiro, Irving M.; Risbud, Makarand V.

2014-01-01

57

Co?culture of human nucleus pulposus cells with multipotent mesenchymal stromal cells from human bone marrow reveals formation of tunnelling nanotubes.  

PubMed

Degeneration of the intervertebral disc (IVD) is the main cause of age-related damage of spinal tissues. Using multipotent mesenchymal stromal cells (MSCs) regenerative medicine intends to restore the IVD components of annulus fibrosus (AF) and nucleus pulposus (NP). In the present study NP cells (NPCs) and MSCs obtained from adolescent patients suffering from scoliosis were used. IVDs and vertebrae were obtained during surgery and subsequently processed in order to establish cultures of NPCs and MSCs. The two cell types were co-cultured in 1-µm pore size insert system (indirect co-culture) or on one surface (direct co-culture). Prior to co-culture in these systems one of the cell types was stained by lipophilic fluorescent dye DiD (red). The results demonstrated that regardless of the cell type, the flow of DiD from stained to non-stained cells was more efficient in the direct co-culture in comparison with the insert system. Moreover, in the direct system the DiD flow was more efficient from MSCs towards NPCs compared with that in the opposite direction. These data indicated that the membrane interchange between the two cell types was asymmetric. To discriminate the subpopulation of cells that underwent membrane interchange, cells were double stained with DiD and DiO (green). In the first part of the experiment NPCs were stained by DiO and MSCs by DiD. In the second, NPCs were stained by DiD and MSCs by DiO. The cells were co-cultured in the direct system for 8 days and subsequently analyzed by flow cytometry and confocal microscopy. This analysis revealed that >50% of cells were stained by the DiO and DiD dyes. NPCs and MSCs formed structures similar to tunnelling nanotubes (TnT). In conclusion, the formation of TnT-like structures is able to promote, phenotypic changes during the direct co-culture of NPCs with MSCs. PMID:24271232

Lehmann, Tomasz P; Filipiak, Krystyna; Juzwa, Wojciech; Sujka-Kordowska, Patrycja; Jagodzi?ski, Pawe? P; Zabel, Maciej; G?owacki, Jakub; Misterska, Ewa; Walczak, Micha?; G?owacki, Maciej

2014-02-01

58

The effect of partial removal of the nucleus pulposus from the intervertebral disc on the response of the human annulus fibrosus to compression  

Microsoft Academic Search

Objective. To determine how partial removal of the nucleus changes the response of the annulus to compression.Design. The deformation of the annulus in the mid-sagittal plane, during compression, was determined from digital video images.Background. Several studies have shown that removal of the nucleus changes the external behaviour of the intervertebral disc, but few studies have investigated changes to internal behaviour.Methods.

Judith R. Meakin; Thomas W. Redpath; David W. L. Hukins

2001-01-01

59

Herniated disk  

MedlinePLUS

... weakness. The lower back (lumbar area) of the spine is the most common area for a slipped disk. The neck (cervical) disks are sometimes affected. The upper-to-mid-back (thoracic) disks are rarely involved. A herniated disk is ...

60

Effect of pathology type and severity on the distribution of MRI signal intensities within the degenerated nucleus pulposus: application to idiopathic scoliosis and spondylolisthesis  

Microsoft Academic Search

BACKGROUND: Disc degeneration is characterized by a loss of cellularity, degradation of the extracellular matrix, and, as a result, morphological changes and biomechanical alterations. We hypothesized that the distribution of the MR signal intensity within the nucleus zone of the intervertebral disc was modified according to the pathology and the severity of the pathology. The objective of this study was

Delphine Périé; Daniel Curnier

2010-01-01

61

Cytotoxic Effects of the Radiocontrast Agent Iotrolan and Anesthetic Agents Bupivacaine and Lidocaine in Three-Dimensional Cultures of Human Intervertebral Disc Nucleus Pulposus Cells: Identification of the Apoptotic Pathways  

PubMed Central

Background Discography and discoblock are imaging procedures used to diagnose discogenic low back pain. Although needle puncture of the intervertebral disc (IVD) itself induces disc degeneration, the agents used in these procedures may also have harmful effects on IVD cells. The purpose of this study was to analyze whether radiocontrast agents and local anesthetic agents have detrimental effects on human nucleus pulposus (NP) cells. Methods Healthy human NP cells were cultured for 7 days in three-dimensional (3D) cell–alginate bead composites, and were then exposed to clinically relevant doses of a radiocontrast agent (iotrolan) or local anesthetic (lidocaine or bupivacaine). Cell viability and apoptosis were measured by confocal microscopy and flow cytometry. On the basis of caspase expression profiles, the apoptotic pathways activated by the agents were identified by Western blot analysis. Results The radiocontrast agent iotrolan did not affect NP cell viability or induce apoptosis. In contrast, both the anesthetic agents significantly decreased cell viability and increased the apoptotic cell number in a time- and dose-dependent manner. After 120 min, 2% lidocaine and 0.5% bupivacaine decreased percent live cells to 13% and 10%, respectively (p<0.05). The number of apoptotic cells was doubled by increasing lidocaine dosage from 1% to 2% (23% and 42%) and bupivacaine from 0.25% to 0.50% (25% and 48%) (p<0.05). Western blot analysis revealed that both anesthetic agents upregulated cleaved caspase-3 and caspase-8, whereas only bupivacaine upregulated cleaved caspase-9. Conclusions/Significance The present study demonstrates that iotrolan does not affect the viability of healthy human NP cells. In contrast, the two anesthetic agents commonly used in discography or discoblock may cause extensive damage to IVDs by inducing apoptotic cell death. PMID:24642945

Iwasaki, Koji; Sudo, Hideki; Yamada, Katsuhisa; Ito, Manabu; Iwasaki, Norimasa

2014-01-01

62

Evolution of disc degeneration in lumbar spine: a comparative histological study between herniated and postmortem retrieved disc specimens.  

PubMed

This is a prospective comparative histological study on blood supply between lumbar herniated discs and postmortem retrieved ones. The aim of this study is to observe the evolution of disc degeneration in relation to its blood supply changes. Disc vascularization is present early in life, but the nucleus pulposus becomes avascular after adolescence. Vascularization of the annulus fibrosus (AF) probably also occurs late in life in association with degenerative changes and in response to trauma. Capillary neoformation and hypervascularity in degenerated discs have also been mentioned, based on animal cases. In the present study, intervertebral lumbar disc specimens were surgically removed from 84 patients with an average age of 41 years (range 24-60 years) operated on for disc herniation. In addition, control autopsy specimens were selected from 24 cadavera with an age of 39 years (range 24th gestation week to 80 years). The material was fixed in neutral buffered formalin, and 4-microm-thick sections were stained with hematoxylin-eosin and reticulin. In addition, with use of an immunohistochemical avidin-biotin complex technique, paraffin sections were stained for Ulex europaeus agglutinin receptors (UEA-1) after binding UEA-1 to the tissue. In surgical specimens, small blood vessels were identified in 45% of the disc cases. They were of the capillary-type vessels and were intermingled with proliferating endothelial cells, fibroblasts, and few mononuclear cells. All of them were located along the edges of the surgically retrieved fibrocartilage fragments. Sometimes thin bands of fibrin were attached to them and extravasated erythrocytes were occasionally seen. In autopsy specimens, blood vessels were identified in 78% of the retrieved discs. In contrast to the edge neovascularity observed in surgical specimens, capillaries were observed at the outer layer of AF surrounded by dense hyalinized and inactive-appearing collagen. From these results it is concluded that the blood vessels in extruded tissue from every type of herniation are newly formed, possibly through metaplasia of undifferentiated mesenchymal cells. It is also possible that they are derived from blood vessels that have invaded the AF as a result of disc degeneration. The finding of detection of progressive disc degeneration in both groups after 20-25 years seems to be of special interest because disc degeneration is a process that may not be directly correlated to disc herniation in these age groups. PMID:9493769

Repanti, M; Korovessis, P G; Stamatakis, M V; Spastris, P; Kosti, P

1998-02-01

63

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 ...

64

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

65

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.; Cuellar, Vanessa Gabrovsky; Yoo, Andrew; Scuderi, Gaetano J.; Yeomans, David C.

2012-01-01

66

Biomechanical and in vivo evaluation of experimental closure devices of the annulus fibrosus designed for a goat nucleus replacement model.  

PubMed

Promising strategies are being developed to replace or regenerate the herniated nucleus pulposus. However, clinical efficacy of these methods has still to be addressed, and the lack of appropriate annulus closure techniques is increasingly being recognised as a major limiting factor. In the current study, in vitro and in vivo evaluation of novel annulus closure devices (ACDs) was performed. These devices are intended to be used in adjunct to nucleus replacement therapies in an experimental goat study. After a standardised discectomy had been performed, different ACDs were implanted solely or in addition to a collagen nucleus replacement implant. Biomechanical effects and axial failure load were assessed in vitro and followed by in vivo evaluation in a goat model. On axial compression, the average axial failure load for ACDs with four barb rings was significantly higher compared to the implants with five barb rings. The increased range of flexion-extension and latero-flexion observed after discectomy were restored to the normal range after implantation of the implants. Positive findings with the four-ring ACD were confirmed in goats after a follow-up of 2 weeks in vivo. However, after 6 weeks most implants (n = 16) showed signs of destruction and displacement. Although there seemed to be a tendency towards better results when ACDs were placed in addition to the nucleus replacements, these differences were not statistically significant. Moreover, two endplate reactions extending into the subchondral bone were observed, most likely due to continuous friction between the ACD and the vertebrae. Although current results are encouraging first steps towards the development of an efficient ACD for animal models, further optimisation is necessary. Current results also show that one cannot rely on in vitro biomechanical studies with annulus closure techniques, and these should always be confirmed in vivo in a large animal model. PMID:20401620

Bron, Johannes L; van der Veen, Albert J; Helder, Marco N; van Royen, Barend J; Smit, Theodoor H

2010-08-01

67

CT recognition of lateral lumbar disk herniation  

SciTech Connect

Although computed tomography (CT) has been shown to be useful in diagnosing posterolateral and central lumbar disk herniations, its effectiveness in demonstrating lateral herniated disks has not been emphasized. The myelographic recognition of those herniations may be difficult because root sheaths or dural sacs may not be deformed. A total of 274 CT scans interpreted as showing lumbar disk herniation was reviewed. Fourteen (5%) showed a lateral disk herniation. The CT features of a lateral herniated disk included: (1) focal protrusion of the disk margin within or lateral to the intervertebral foramen: (2) displacement of epidural fat within the intervertebral foramen; (3) absence of dural sac deformity; and (4) soft-tissue mass within or lateral to the intervertebral foramen. Because it can image the disk margin and free disk fragments irrespective of dural sac or root sheath deformity, CT may be more effective than myelography for demonstrating the presence and extent of lateral disk herniation.

Williams, A.L.; Haughton, V.M.; Daniels, D.L.; Thornton, R.S.

1982-08-01

68

Migrated herniated disc mimicking a neoplasm  

Microsoft Academic Search

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

Benjamin Hoch; George Hermann

2010-01-01

69

Incidence of trocar site herniation following robotic gynecologic surgery  

PubMed Central

Objective Trocar site herniation is a recognized complication of minimally invasive surgery, but published data on trocar site herniation after robotic surgery are scarce. We sought to determine the incidence of trocar site herniation in women undergoing robotic surgery for gynecologic disease. Methods A retrospective review of robotic surgeries performed from January 1, 2006, through December 31, 2012, was conducted. Postoperative trocar site herniations were identified, along with time to presentation, location of herniation, and management. Patients were excluded if surgery was converted to laparotomy or traditional laparoscopy. The Wilcoxon rank-sum test was used to compare patients with and without herniation with respect to continuous variables, and Fisher's exact test was used to compare these 2 groups with respect to categorical variables. Results The study included 500 patients, 3 of whom experienced herniation at a single trocar site. The patients with and without herniation did not differ with respect to age, body mass index, smoking status, medical comorbidities, operating time, or estimated blood loss. All 3 herniations occurred at 12-mm trocar sites. Two herniations occurred at assistant port sites, and 1 occurred at the umbilical camera port site. The median time to herniation was 21 days (range, 8-38 days). One patient required immediate surgical intervention; the other 2 patients had conservative management. Conclusions Trocar site herniation is a rare complication following robotic surgery. The most important risk factor for trocar site herniation appears to be larger trocar size, as all herniations occurred at 12-mm port sites. PMID:23988416

Clark, Leslie H.; Soliman, Pamela T.; Odetto, Diego; Munsell, Mark F.; Schmeler, Kathleen M.; Fleming, Nicole; Westin, Shannon N.; Nick, Alpa M.; Ramirez, Pedro T.

2014-01-01

70

Characterization of novel photocrosslinked carboxymethylcellulose hydrogels for encapsulation of nucleus pulposus cells  

Microsoft Academic Search

Back pain is a significant clinical concern often associated with degeneration of the intervertebral disc (IVD). Tissue engineering strategies may provide a viable IVD replacement therapy; however, an ideal biomaterial scaffold has yet to be identified. One candidate material is carboxymethylcellulose (CMC), a water-soluble derivative of cellulose. In this study, 90 and 250kDa CMC polymers were modified with functional methacrylate

Anna T. Reza; Steven B. Nicoll

2010-01-01

71

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

72

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

73

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 clinically known as Herniation) using shape potentials. We extract these shape potentials by jointly applying cold. In fact, it is the most common reason patients visited the emergency room in the U.S. in 2008

Corso, Jason J.

74

Lung herniation: a rare complication in minimally invasive cardiothoracic surgery  

Microsoft Academic Search

Objective: Lung herniation, defined as a protrusion of the lung parenchyma with pleural membranes through a defect of the thoracic wall, is a rare entity. As minimally invasive cardiac procedures evolve, different complications may be evident such as lung herniation. A retrospective review of all patients submitted to minimally invasive cardiac or transplant surgery through anterior mini-thoracotomy at our department

Kalliopi Athanassiadi; Erik Bagaev; Andre Simon; Axel Haverich

2010-01-01

75

Lung herniation: a rare complication in minimally invasive cardiothoracic surgery  

Microsoft Academic Search

Objective: Lung herniation, defined as a protrusion of the lung parenchyma with pleural membranes through a defect of the thoracic wall, is a rare entity. As minimally invasive cardiac procedures evolve, different complications may be evident such as lung herniation. A retrospective review of all patients submitted to minimally invasive cardiac or transplant surgery through anterior mini-thoracotomy at our department

Kalliopi Athanassiadi; Erik Bagaev; Andre Simon; Axel Haverich

2008-01-01

76

Intradural disc herniations pathogenesis, clinical picture, diagnosis and treatment  

Microsoft Academic Search

Summary The relatively rare occurrence and uncertainty about pathogenesis of intradurally displaced disc herniations stimulated an anatomico-pathological study into intradural disc herniations. The relation between the ventral dura and posterior longitudinal ligament in the cervical, thoracic, lumbar and sacral regions were examined macroscopically and microscopically, and ventral and dorsal durai thickness was compared in 20 adult autopsies on patients who

A. Yildizhan; A. Pa?ao?lu; T. Okten; N. Ekinci; K. Aycan; Ö. Aral

1991-01-01

77

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

78

Sacral perineural cyst accompanying disc herniation.  

PubMed

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, Seok Won; Kim, Hyeun Sung

2009-03-01

79

Nucleus implantation: the biomechanics of augmentation versus replacement with varying degrees of nucleotomy.  

PubMed

Nucleus pulposus replacement and augmentation has been proposed to restore disk mechanics in early stages of degeneration with the option of providing a minimally invasive procedure for pain relief to patients with an earlier stage of degeneration. The goal of this paper is to examine compressive stability of the intervertebral disk after either partial nucleus replacement or nuclear augmentation in the absence of denucleation. Thirteen human cadaver lumbar anterior column units were used to study the effects of denucleation and augmentation on the compressive mechanical behavior of the human intervertebral disk. Testing was performed in axial compression after incremental steps of partial denucleation and subsequent implantation of a synthetic hydrogel nucleus replacement. In a separate set of experiments, the disks were not denucleated but augmented with the same synthetic hydrogel nucleus replacement. Neutral zone, range of motion, and stiffness were measured. The results showed that compressive stabilization of the disk can be re-established with nucleus replacement even for partial denucleation. Augmentation of the disk resulted in an increase in disk height and intradiskal pressure that were linearly related to the volume of polymer implanted. Intervertebral disk instability, evidenced by increased neutral zone and ranges of motion, associated with degeneration can be restored by volume filling of the nucleus pulposus using the hydrogel device presented here. PMID:24599572

Cannella, Marco; Isaacs, Jessica L; Allen, Shanee; Orana, Argjenta; Vresilovic, Edward; Marcolongo, Michele

2014-05-01

80

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

81

Idiopathic brain herniation. A report of two paediatric cases.  

PubMed

SUMMARY - 'Idiopathic' herniation of the brain is a rare entity previously reported in 13 cases. It may be incidentally encountered in neuroimaging studies acquired for various clinical indications. We herein describe two cases of idiopathic brain herniation that were incidentally diagnosed. A 12-year-old boy presented with a six-month history of daytime sleepiness and sudden spells of sleep. Herniation of the left inferior temporal gyrus was revealed in MRI acquired with the suspicion of epilepsy. His overnight polysomnogram and multiple sleep latency tests were compatible with the diagnosis of narcolepsy. The other case, a two-year-old girl, was transferred from an outside hospital due to partial seizures with the fever. Herniation of the precuneal gyrus was encountered in MRI acquired after controlling her seizures with the initiation of phenytoin. The brain herniations of both patients were considered to be inconsistent with their medical conditions, so that they were symptom-free with only medical treatment for following three and six months, respectively. This is a rare presentation of idiopathic brain herniation as an incidental finding that accompanied narcolepsy and epilepsy. Awareness of this entity would avoid excessive surgical and medical treatments. PMID:25260205

Koc, Gonca; Doganay, Selim; Bayram, Ayse Kacar; Gorkem, Sureyya Burcu; Dogan, Mehmet Sait; Per, Huseyin; Coskun, Abdulhakim

2014-10-01

82

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

83

Outcomes of cervical and lumbar disk herniations in Major League Baseball pitchers.  

PubMed

The effects of disk herniations on the career and performance outcomes of Major League Baseball (MLB) pitchers are unknown. The purpose of this study is to determine the outcomes after a cervical or lumbar disk herniation for MLB pitchers. Forty MLB pitchers from 1984 to 2009 with a cervical disk herniation or lumbar disk herniation were identified using a previously established protocol. Cervical disk herniation was identified in 11 pitchers, 8 of which were treated operatively. The majority of pitchers with cervical disk herniation (8/11) returned to play at an average of 11.6 months. Lumbar disk herniation was identified in 29 pitchers, 20 of which were treated operatively. All pitchers with lumbar disk herniation (29/29) returned to play at an average of 7.3 months after diagnosis. PMID:21800814

Roberts, David W; Roc, Gilbert J; Hsu, Wellington K

2011-08-01

84

Intradural disc herniation at L5 level mimicking an intradural spinal tumor  

Microsoft Academic Search

Intradural lumbar disc herniation is a rare complication of disc disease. The reason for the tearing of the dura matter by\\u000a a herniated disc is not clearly known. Intradural disc herniations usually occur at the disc levels and are often seen at\\u000a L4–L5 level but have also been reported at other intervertebral disc levels. However, intradural disc herniation at mid-vertebral

Chang-Chih Liu; Chih-Ta Huang; Chih-Ming Lin; Kan-Nan Liu

2011-01-01

85

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

86

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

87

Repair of tibialis anterior muscle herniation using periosteum.  

PubMed

Muscular herniation consists of focal muscular protrusions through an acquired or congenital fascial defect. The anterior tibialis muscle is most frequently affected. Asymptomatic muscle hernias are usually treated conservatively. For severe symptoms or cosmetic complaints, several surgical techniques are available to treat muscle herniation, including fasciotomy, fascial patch grafting using autologous fascia lata, or synthetic mesh. However, the optimal surgical approach remains debatable. The authors propose a novel and reproducible surgical method using a periosteal turn-down technique. This surgical technique has the advantages of fewer complications, greater cost-effectiveness, and high reproducibility. The authors find this to be a useful technique. [Orthopedics. 2014; 37(11):748-750.]. PMID:25361358

Harwin, Steven F; Choi, Young-Rak; Hong, Chul-Gie

2014-11-01

88

Flaccid quadriplegia from tonsillar herniation in pneumococcal meningitis  

Microsoft Academic Search

A young woman with fulminant pyogenic meningitis became quadriplegic, areflexic and flaccid due to herniation of the cerebellar tonsils and compression of the upper cervical cord. This state of spinal shock was associated with absent F-waves. Intracranial pressure was greatly elevated and there was an uncertain relationship of tonsillar descent to a preceding lumbar puncture. Partial recovery occurred over 2

A. H. Ropper; K. B. Kanis

2000-01-01

89

Skull malformation and cerebellar herniation in captive African lions  

Microsoft Academic Search

Thickening of the cranial vault with a resulting cerebellar herniation is described in a series of litters of lion cubs, all with the same parents, one of whom was also very mildly affected. This animal, when mated to his daughter, also produced affected cubs. The aetiology of the condition is discussed and it is considered that vitamin A deficiency may

JR Baker; DG Lyon

1977-01-01

90

The cost-utility of lumbar disc herniation surgery.  

PubMed

The cost and utility of surgery for a herniated lumbar disc has not been determined simultaneously in a single cohort. The aim of this study is to perform a cost-utility analysis of surgical and nonsurgical treatment of patients with lumbar disc herniation. Ninety-two individuals in a cohort of 1,146 Swedish subjects underwent lumbar disc herniation surgery during a 2-year study. Each person operated on was individually matched with one treated conservatively. The effects and costs of the treatments were determined individually. By estimating quality of life before and after the treatment, the number of quality adjusted life years (QALY) gained with and without surgery was calculated. The medical costs were much higher for surgical treatment; however, the total costs, including disability costs, were lower among those treated surgically. Surgery meant fewer recurrences and less permanent disability benefits. The gain in QALY was ten times higher among those operated. Lower total costs and better utility resulted in a better cost utility for surgical treatment. Surgery for lumbar disc herniation was cost-effective. The total costs for surgery were lower due to lower recurrence rates and fewer disability benefits, and surgery improved quality of life much more than nonsurgical treatments. PMID:16683121

Hansson, Elisabeth; Hansson, Tommy

2007-03-01

91

Notochordal conditioned media from tissue increases proteoglycan accumulation and promotes a healthy nucleus pulposus phenotype in human mesenchymal stem cells  

Microsoft Academic Search

Introduction  Notochordal cells (NCs) are influential in development of the intervertebral disc (IVD) and species that retain NCs do not\\u000a degenerate. IVD repair using bone marrow derived mesenchymal stem cells (MSCs) is an attractive approach and the harsh microenvironment\\u000a of the IVD suggests pre-differentiation is a necessary first step. The goal of this study was to use soluble factors from\\u000a NCs

Devina Purmessur; Rachel M Schek; Rosalyn D Abbott; Bryan A Ballif; Karolyn E Godburn; James C Iatridis

2011-01-01

92

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

93

Lumbar-sacral radiculopathy secondary to intraspinal synovial cyst  

Microsoft Academic Search

Objective:The presentation of a patient with acute low back pain and distal radiation to the lower extremities is often attributed to a herniated nucleus pulposus (NHP). The purpose of this report is to illustrate how an intraspinal lumbar synovial cyst can have a similar presentation.

Philip Jordan Marion; Neil Kahanovitz

1995-01-01

94

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

95

Asymptomatic tonsillar herniation in a neonate with cleidocranial dysplasia.  

PubMed

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

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

2014-02-01

96

Hemifacial hyperhidrosis associated with ipsilateral/contralateral cervical disc herniation myelopathy. Functional considerations on how compression pattern determines the laterality  

PubMed Central

Summary Sweating is an important mechanism for ensuring constant thermoregulation, but hyperhidrosis may be disturbing. We present five cases of hemifacial hyperhidrosis as a compensatory response to an/hypohidrosis caused by cervical disc herniation. All the patients complained of hemifacial hyperhidrosis, without anisocoria or blepharoptosis. Sweat function testing and thermography confirmed hyperhidrosis of hemifacial and adjacent areas. Neck MRI showed cervical disc herniation. Three of the patients had lateral compression with well-demarcated hypohidrosis below the hyperhidrosis on the same side as the cervical lesion. The rest had paramedian compression with poorly demarcated hyperhidrosis and hypohidrosis on the contralateral side. Although MRI showed no intraspinal pathological signal intensity, lateral dural compression might influence the circulation to the sudomotor pathway, and paramedian compression might influence the ipsilateral sulcal artery, which perfuses the sympathetic descending pathway and the intermediolateral nucleus. Sweat function testing and thermography should be performed to determine the focus of the hemifacial hyperhidrosis, and the myelopathy should be investigated on both sides. PMID:25014051

Iwase, Satoshi; Inukai, Yoko; Nishimura, Naoki; Sato, Maki; Sugenoya, Junichi

2014-01-01

97

Automatic diagnosis of lumbar disc herniation with shape and appearance features from MRI  

NASA Astrophysics Data System (ADS)

Intervertebral disc herniation is a major reason for lower back pain (LBP), which is the second most common neurological ailment in the United States. Automation of herniated disc diagnosis reduces the large burden on radiologists who have to diagnose hundreds of cases each day using clinical MRI. We present a method for automatic diagnosis of lumbar disc herniation using appearance and shape features. We jointly use the intensity signal for modeling the appearance of herniated disc and the active shape model for modeling the shape of herniated disc. We utilize a Gibbs distribution for classification of discs using appearance and shape features. We use 33 clinical MRI cases of the lumbar area for training and testing both appearance and shape models. We achieve over 91% accuracy in detection of herniation in a cross-validation experiment with specificity of 91% and sensitivity of 94%.

Alomari, Raja'S.; Corso, Jason J.; Chaudhary, Vipin; Dhillon, Gurmeet

2010-03-01

98

Nucleus Research Inc. NucleusResearch.com  

E-print Network

Nucleus Research Inc. NucleusResearch.com Corporate Headquarters Nucleus Research Inc. 100 State these support agreements, Nucleus analyzed deployments at a number of companies, including US Lumber, Blue Mountain Resorts, Martin's Point, and Ryerson. THE BENEFITS IBM COGNOS SUPPORT Companies that augment

99

Herniation of the temporomandibular joint into the external auditory meatus secondary to benign necrotising otitis externa  

Microsoft Academic Search

The temporomandibular joint (TMJ) is intimately related to the external auditory meatus (EAM). Herniation of the joint into the EAM occurs secondary to neoplasia, trauma, inflammation and developmental problems [Conover GL, Crammond RJ. Tympanic plate fracture from mandibular trauma. J Oral Maxillofac Surg 1985;43:292–4; Ali TS, Rubinstein JT. Rheumatoid arthritis of the temporomandibular joint with herniation into the external auditory

Neil C.-W. Tan; Alan Wilson; Jonathan Buckland

2009-01-01

100

Recurrent wound dehiscence and small bowel herniation following Caesarean section in a woman with hidradenitis suppurativa.  

PubMed

Caesarean wound dehiscence that is severe enough to result in bowel herniation is exceptionally rare. This case describes a woman who experienced wound dehiscence following each of her two Caesarean sections, with bowel herniation present in the second case. The contribution of her comorbid hidradenitis suppurativa will be discussed. PMID:24876503

Fernando, Magage; Schultz, Meleesa J

2014-01-01

101

Recurrent wound dehiscence and small bowel herniation following Caesarean section in a woman with hidradenitis suppurativa  

PubMed Central

Caesarean wound dehiscence that is severe enough to result in bowel herniation is exceptionally rare. This case describes a woman who experienced wound dehiscence following each of her two Caesarean sections, with bowel herniation present in the second case. The contribution of her comorbid hidradenitis suppurativa will be discussed. PMID:24876503

Fernando, Magage; Schultz, Meleesa J.

2014-01-01

102

Hindbrain herniation develops in surgically created myelomeningocele but is absent after repair in fetal lambs  

Microsoft Academic Search

Objective: The purpose of our study was to determine whether prenatal repair of myelomeningocele prevents or reverses hindbrain herniation in the sheep model. Study Design: A myelomeningocele was surgically created in fetal sheep. One group was repaired later in utero; the others were delivered without repair. After delivery, lambs were assessed for the presence of hindbrain herniation. Results: In all

Bettina W. Paek; Diana L. Farmer; C. Corbett Wilkinson; Craig T. Albanese; Warrick Peacock; Michael R. Harrison; Russell W. Jennings

2000-01-01

103

Psychopathological Influence of Lumbar Disc Herniation in Male Adolescent  

PubMed Central

Purpose There is no report about psychopathological effect causing by disc herniation. The disease could impose psychopathological influence on the social life, the treatment period, and response to the treatment. This study was to evaluate retrospectively the psychopathological influence of lumbar disc herniation (LDH) among Korean 19-year-old males. Materials and Methods We compared the Korean military multiphasic personality inventory (KMPI) profiles of 74 LDH cases with the KMPI profiles of 150 controls. The LDH groups were categorized to 2 groups according to the presence of thecal sac compression by disc materials, and evaluated the relation between the KMPI and LDH. Results The decrease of the faking-good response scale and increase of the faking-bad response scale were observed more in the LDH group than in the normal volunteer group (p<0.05). The neurosis set such as anxiety, depression and somatization was markedly increased in the LDH group compared to the normal volunteers group (p<0.05). The scale of personality disorder was also increased more in the LDH group (p=0.002). The differences of KMPI scales were not correlated with the severe pathology of LDH. Conclusion Young male with LDH may tend to have more abnormal results of multiphasic personality inventory test compared to the normal volunteers, suggesting that LDH may be related to the psychopathology in young males in Korea. Therefore, clinicians are recommended to evaluate and treat the psychopathological aspects in patients with LDH. PMID:23709412

Kim, Tae Woo; Oh, Chang Hyun; Shim, Yu Sik; Park, Hyeong-chun; Park, Chong Oon

2013-01-01

104

Posteriorly migrated thoracic disc herniation: a case report  

PubMed Central

Introduction Posterior epidural migration of thoracic disc herniation is extremely rare but may occur in the same manner as in the lumbar spine. Case presentation A 53-year-old Japanese man experienced sudden onset of incomplete paraplegia after lifting a heavy object. Magnetic resonance imaging revealed a posterior epidural mass compressing the spinal cord at the T9-T10 level. The patient underwent emergency surgery consisting of laminectomy at T9-T10 with right medial facetectomy, removal of the mass lesion, and posterior instrumented fusion. Histological examination of the mass lesion yielded findings consistent with sequestered disc material. His symptoms resolved, and he was able to resume walking without a cane 4 weeks after surgery. Conclusions Pre-operative diagnosis of posterior epidural migration of herniated thoracic disc based on magnetic resonance imaging alone may be overlooked, given the rarity of this pathology. However, this entity should be considered among the differential diagnoses for an enhancing posterior thoracic extradural mass. PMID:23402642

2013-01-01

105

The effect of nucleus implant parameters on the compressive mechanics of the lumbar intervertebral disc: a finite element study.  

PubMed

A simplified finite element model of the human lumbar intervertebral disc was utilized for understanding nucleus pulposus implant mechanics. The model was used to assess the effect of nucleus implant parameter variations on the resulting compressive biomechanics of the lumbar anterior column unit. The effects of nucleus implant material (modulus and Poisson's ratio) and geometrical (height and diameter) parameters on the mechanical behavior of the disc were investigated. The model predicted that variations in implant modulus contribute less to the compressive disc mechanics compared to the implant geometrical parameters, for the ranges examined. It was concluded that some threshold exists for the nucleus implant modulus, below which little variations in load-displacement behavior were shown. Compressive biomechanics were highly affected by implant volume (under-filling the nucleus cavity, line-to-line fit, or over-filling the nucleus cavity) with a greater restoration of compressive mechanics observed with the over-filled implant design. This work indicated the effect of nucleus implant parameter variations on the compressive mechanics of the human lumbar intervertebral disc and importance of the "fit and fill" effect of the nuclear cavity in the restoration of the human intervertebral disc mechanics in compression. These findings may have clinical significance for nucleus implant design. PMID:19180527

Joshi, Abhijeet; Massey, Christopher J; Karduna, Andrew; Vresilovic, Edward; Marcolongo, Michele

2009-08-01

106

Nucleus Research Inc. NucleusResearch.com  

E-print Network

Nucleus Research Inc. NucleusResearch.com Corporate Headquarters Nucleus Research Inc. 100 State in the assesment of specific training needs so that end-user adoption is both high and fulfills business, so that skills gaps can be identified and addressed. Enterprise learning licenses (ELL), under which

107

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

108

Sagittal spinal alignment in patients with lumbar disc herniation.  

PubMed

A retrospective cross-sectional study was designed to evaluate total sagittal spinal alignment in patients with lumbar disc herniation (LDH) and healthy subjects. Abnormal sagittal spinal alignment could cause persistent low back pain in lumbar disease. Previous studies analyzed sciatic scoliotic list in patients with lumbar disc herniation; but there is little or no information on the relationship between sagittal alignment and subjective findings. The study subjects were 61 LDH patients and 60 age-matched healthy subjects. Preoperative and 6-month postoperatively lateral whole-spine standing radiographs were assessed for the distance between C7 plumb line and posterior superior corner on the top margin of S1 sagittal vertical axis (SVA), lumbar lordotic angle between the top margin of the first lumbar vertebra and first sacral vertebra (L1S1), pelvic tilting angle (PA), and pelvic morphologic angle (PRS1). Subjective symptoms were evaluated by the Japanese Orthopedic Association (JOA) score for lower back pain (nine points). The mean SVA value of the LDH group (32.7 +/- 46.5 mm, +/- SD) was significantly larger than that of the control (2.5 +/- 17.1 mm), while L1S1 was smaller (36.7 +/- 14.5 degrees ) and PA was larger (25.1 +/- 9.0 degrees ) in LDH than control group (49.0 +/- 10.0 degrees and 18.2 +/- 6.0 degrees , respectively). At 6 months after surgery, the malalignment recovered to almost the same level as the control group. SVA correlated with the subjective symptoms measured by the JOA score. Sagittal spinal alignment in LDH exhibits more anterior translation of the C7 plumb line, less lumbar lordosis, and a more vertical sacrum. Measurements of these spinal parameters allowed assessment of the pathophysiology of LDH. PMID:20091188

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

2010-03-01

109

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

PubMed Central

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

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

2013-01-01

110

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

PubMed Central

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

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

2014-01-01

111

[Abdominal wall closure by incisional hernia and herniation after laparostoma].  

PubMed

As hernias and abdominal wall defects have a variety of etiologies each with its own complications and comorbidities in various constellations, efficient treatment requires patient-oriented management. There is no recommended standard treatment and the very different clinical pictures demand an individualized interdisciplinary approach. Particularly in the case of complicated hernias, the planning of the operation should focus on the problems posed by the individual patient. Treatment mainly depends on the etiology of the hernia, immediate or long-term complications and the efficiency of individual repair techniques. Abdominal wall repair for recurrent herniation requires direct closure of the fascia generally using the sublay technique with a lightweight mesh. It is still unclear whether persistent inflammation, mesh dislocation, fistula formation or other long-term complications are due to certain materials or to the surgical technique. With mesh infections it has been shown to be advantageous to remove a polytetrafluoroethylene (PTFE) mesh, while the combination of systemic and local treatment appears to suffice for a polypropylene or polyester mesh. Heavier meshes in the sublay position or plastic reconstruction with autologous tissue are indicated as substitutes for the abdominal wall for giant hernias, repeated recurrences and large abdominal wall defects. A laparostoma is increasingly more often created to treat septic intra-abdominal processes but is very often responsible for a complicated hernia. If primary repair of the abdominal wall is not an option, resorbable material or split skin is used for coverage under the auspices of a planned hernia repair. PMID:20145901

Mischinger, H-J; Kornprat, P; Werkgartner, G; El Shabrawi, A; Spendel, S

2010-03-01

112

What about the nucleus?  

NSDL National Science Digital Library

What holds the nucleus together? This web page, part of a tutorial on particle physics, focuses on what possible forces may hold the nucleus together. Students are questioned why the nucleus doesn't blast apart due to all of the positive particles packed so tightly together. Students learn that electromagnetic forces and gravitational forces are not strong enough to hold the nucleus together. Copyright 2005 Eisenhower National Clearinghouse

Group, Lawrence B.

2002-01-01

113

Epidural steroid injections are useful for the treatment of low back pain and radicular symptoms: pro.  

PubMed

Epidural steroid injection has been used to treat low back pain for many decades. Numerous randomized trials have examined the efficacy of this approach. This review details the findings of older systematic reviews, newer randomized controlled trials, and two recent systematic reviews that examine the effectiveness of this treatment. Collectively, studies in acute radicular pain due to herniated nucleus pulposus have failed to show that epidural steroid injection reduces long-term pain or obviates the need for surgery. Similarly, there is scant evidence that epidural steroids have any beneficial effect in those with acute low back pain without leg pain or in those with chronic low back or leg pain. However, most studies have demonstrated more rapid resolution of leg pain in those who received epidural steroid injections versus those who did not. The role of epidural steroid injections in the management of acute radicular pain due to herniated nucleus pulposus is simply to provide earlier pain relief. PMID:19126368

Sethee, Jai; Rathmell, James P

2009-02-01

114

Ultrasound-Guided Posterolateral Approach for Midline Calcified Thoracic Disc Herniation  

PubMed Central

Objective Symptomatic thoracic disc herniation often requires prompt surgical treatment to prevent neurological deterioration and permanent deficits. Anterior approaches offer direct visualization and access to the herniated disc and anterior dura but require access surgeons and are often associated with considerable postoperative pain and pulmonary complications. A disadvantage with using posterior approaches in the setting of central calcified thoracic disc herniation however, has been the limited visualization of anterior dura and difficulty to accurately assess the extent of decompression. Methods We report our experience with intraoperative ultrasound (US) guidance during a modified posterior transpedicular approach for removal of a central calcified thoracic disc herniation with a review of pertinent literature. Results The herniated thoracic disc was successfully removed with posterior approach with the aid of intraoperative US. The patient had significant neurological improvement at three months follow-up. Conclusion Intraoperative ultrasound is a simple yet valuable tool for real-time imaging during transpedicular thoracic discectomy. Visualization provided by intraoperative US increases the safety profile of posterior approaches and may make thoracotomy unnecessary in a selected group of patients, especially when a patient has existing pulmonary disease or is otherwise not medically fit for the transthoracic approach.

Lopes, Demetrius K.; Fontes, Ricardo B. V.

2014-01-01

115

Enucleation/partial nephrectomy for large mixed epithelial stromal tumor and herniating into the pelvicalyceal system  

PubMed Central

Objectives: Mixed Epithelial and Stromal Tumor of the kidney is an adult renal neoplasm. It is mostly benign in nature. Typically it is composed of a mixture of epithelial and mesenchymal components. We hereby report on the feasibility of performing partial nephrectomy/enucleation for Huge Mixed Epithelial Stromal Tumor of the kidney without sacrificing the involved renal unit even in the tumors herniating into the collecting system. Methods: Two female patients on long term hormonal therapy developed large enhancing multiloculated and septated renal masses. Kidney mass size was 18.5 cms in one patient and 11.5 in the second. In one patient, the mass was herniating into the collecting system. Both patients had enucleation/partial nephrectomy. Results: Enucleation and partial nephrectomy were successfully performed in both patients. In the patient with the mass herniating into the collecting system, the horns of the mass herniating into the collecting system were easily enucleated with repair of the collecting system and salvage of the involved renal unit. Post op pathology revealed MEST in both patients. There were no intraoperative or postoperative complications. Conclusions: Enucleation and partial nephrectomy for huge MEST is feasible. Mixed Epithelial Stromal Tumor herniating into the pelvicalyceal system may not warrant nephroureterectomy as previously reported. PMID:25371624

Kamel, Mohamed H.; Davis, Rodney; Cox, Roni M.; Cole, Adam; Eltahawy, Ehab

2014-01-01

116

Lumbar intraspinal extradural ganglion cyst  

PubMed Central

A case is presented of an intraspinal extradural ganglion cyst at the L4–5 level. The clinical picture suggested a herniated nucleus pulposus at this level. A myelogram revealed a round lesion almost completely obstructing the flow of Pantopaque at the L4–5 level. A ganglion cyst with a haemorrhage into it and the surrounding tissue was removed, and surgery was followed by complete recovery. Images PMID:4647850

Brish, Adam; Payan, Hushong M.

1972-01-01

117

Relationship between low-back pain, muscle spasm and pressure pain thresholds in patients with lumbar disc herniation  

Microsoft Academic Search

It is not known whether or not muscle spasm of the back muscles presented in patients with sciatic scoliosis caused by lumbar disc herniation produces muscle pain and\\/or tenderness. Pressure pain thresholds (PPTs) of the lower back and low-back pain were examined in 52 patients (13 of 52 presenting sciatic scoliosis) with lumbar disc herniation who complained of radicular pain

Jiro Hirayama; Masatsune Yamagata; Satoshi Ogata; Koh Shimizu; Yoshikazu Ikeda; Kazuhisa Takahashi

2006-01-01

118

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

119

Herniation of the temporomandibular joint into the external auditory meatus secondary to benign necrotising otitis externa.  

PubMed

The temporomandibular joint (TMJ) is intimately related to the external auditory meatus (EAM). Herniation of the joint into the EAM occurs secondary to neoplasia, trauma, inflammation and developmental problems [Conover GL, Crammond RJ. Tympanic plate fracture from mandibular trauma. J Oral Maxillofac Surg 1985;43:292-4; Ali TS, Rubinstein JT. Rheumatoid arthritis of the temporomandibular joint with herniation into the external auditory canal. Ann Otol Rhinol Laryngol 2000;109:177-9]. Benign necrotising otitis externa (BNOE) is an uncommon condition characterized by avascular necrosis of the tympanic plate that has been described as a sequela of simple otitis externa. [Wormald PJ. Surgical management of benign necrotizing otitis externa. J Laryngol Otol 1994;108:101-5.] We present a case of BNOE that resulted in a posterior herniation of the TMJ capsule into the EAM. PMID:18848375

Tan, Neil C-W; Wilson, Alan; Buckland, Jonathan

2009-03-01

120

Translational research of herniated discs: current status of diagnosis and treatment.  

PubMed

Lumbar herniated discs commonly occur in patients 20-40 years of age, and result in acute symptoms of shooting and intractable pain in the low back and/or lower extremities. However, the prognosis of these patients is considered to be very good. Moreover, 70% of these patients have been reported to be free from sciatica at approximately 6 months after the first onset. Magnetic resonance imaging (MRI) studies have described the spontaneous resorption process of herniated discs, which is a major cause of the reduction of symptoms in patients. New advancements in MRI have recently been developed that have facilitated the examination of nerve tract fibers and identification of symptomatic nerve tissue. Furthermore, the mechanism underlying the resorption process of a herniated disc has been determined. Inflammatory cytokines such as TNF (tumor necrosis factor)-?, angiogenic factors such as vascular endothelial growth factor, and enzymes such as matrix metalloproteinases are intricately related to each other. In our previous studies, matrix metalloproteinase-7 (MMP-7) has been shown to play a crucial role in the initiation of herniated disc resorption. Therefore, we developed recombinant human MMP-7 for intradiscal therapy through an industry-university joint research program. We have already performed in vitro and in vivo experiments to confirm its efficacy; this therapy avoids the side effects associated with surgery, such as nerve tissue damage. Moreover, the phase 1/2 studies of recombinant human (rh) MMP-7 are currently ongoing in the United States, and careful monitoring is required for these clinical trials. In conclusion, patients with lumbar herniated discs may benefit from the development of a less invasive treatment for disc herniation, which can be applied even immediately after the onset of disease symptoms. PMID:24777237

Haro, Hirotaka

2014-07-01

121

The Inguinal Herniation of the Ovary in the Newborn: Ultrasound and Color Doppler Ultrasound Findings  

PubMed Central

Inguinal hernias in the newborn age group are seldom encountered. In the affected female patient, the ovaries, fallopian tubes, and the intestines may settle in the hernia sac. The early diagnosis of torsion in cases in which the ovary is herniated into the inguinal canal is of utmost importance in order to give surgery the chance of reduction and correction. In this paper, a case of an ovarian herniation into the inguinal canal without the presence of torsion is being presented, and the place of US and CDUS in the differential diagnosis of the situation is being discussed. PMID:24795829

Kaya, Omer; Esen, Kaan; Gulek, Bozkurt; Yilmaz, Cengiz; Soker, Gokhan; Onem, Onder

2014-01-01

122

Port Site Herniation of the Small Bowel following Laparoscopic-Myomectomy  

PubMed Central

Bowel herniation, through fascial defects secondary to laparoscopic surgery at the site of trocar entry, is a rare, but potentially serious, complication. Closure of the fascia at port sites measuring 10mm or more has been highly recommended to avoid such complications. We report a case of a small bowel which herniated and strangulated through the port site immediately after laparoscopic myomectomy. Resection of the strangulated bowel with primary anastomosis was required to manage this complication. We present this case report with literature review to discuss the risk factors and the methods to prevent such a complication post laparoscopic surgery. PMID:21509090

Elshafie, Ghazi A; Al-Wahaibi, Khalifa; Al-Azri, Ahmed; Al-Qadhi, Hani; Al-Harthi, Abdullah

2010-01-01

123

Single Lung Retransplantation for Graft Infarction due to Herniation of Heart  

PubMed Central

A young woman with terminal respiratory failure due to idiopathic pulmonary hypertension underwent bilateral lung transplantation. The postoperative course was complicated by herniation of the heart through over the cut pericardial edge on left side leading to left-sided graft infarction requiring pneumonectomy. Unable to wean off mechanical ventilation, patient required lobar transplantation on the left side. PMID:25360412

Mohite, Prashant N.; Sabashnikov, Anton; Rao, Praveen; Zych, Bartlomiej; Simon, Andre

2013-01-01

124

Idiopathic Ventral Spinal Cord Herniation: An Increasingly Recognized Cause of Thoracic Myelopathy  

PubMed Central

Idiopathic spinal cord herniation (ISCH), where a segment of the spinal cord has herniated through a ventral defect in the dura, is a rarely encountered cause of thoracic myelopathy. The purpose of our study was to increase the clinical awareness of this condition by presenting our experience with seven consecutive cases treated in our department since 2005. All the patients developed pronounced spastic paraparesis or Brown-Séquard syndrome for several years (mean, 4.7 years) prior to diagnosis. MRI was consistent with a transdural spinal cord herniation in the mid-thoracic region in all the cases. The patients underwent surgical reduction of the herniated spinal cord and closure of the dural defect using an artificial dural patch. At follow-up, three patients experienced considerable clinical improvement, one had slight improvement, one had transient improvement, and two were unchanged. Two of the four patients with sphincter dysfunction regained sphincter control. MRI showed realignment of the spinal cord in all the patients. ISCH is probably a more common cause of thoracic myelopathy than previously recognized. The patients usually develop progressive myelopathy for several years before the correct diagnosis is made. Early diagnosis is important in order to treat the patients before the myelopathy has become advanced. PMID:25336997

Berg-Johnsen, Jon; Ilstad, Eivind; Kolstad, Frode; Zuchner, Mark; Sundseth, Jarle

2014-01-01

125

Herniation and strangulation of the gallbladder through the foramen of Winslow  

SciTech Connect

Herniation of the gallbladder through the foramen of Winslow into the lesser sac is rare. In this case, the diagnosis was suggested by sonography, investigated further by radionuclide and computed tomographic (CT) studies, and confirmed by percutaneous needle puncture and opacification.

Bach, D.B.; Satin, R.; Palayew, M.; Lisbona, R.; Tessler, F.

1984-03-01

126

Endoscopic Transforaminal Thoracic Foraminotomy and Discectomy for the Treatment of Thoracic Disc Herniation  

PubMed Central

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

127

Spontaneous Cervical Intradural Disc Herniation Associated with Ossification of Posterior Longitudinal Ligament  

PubMed Central

Intradural herniation of a cervical disc is rare; less than 35 cases have been reported to date. A 52-year-old man with preexisting ossification of posterior longitudinal ligament developed severe neck pain with Lt hemiparesis while asleep. Neurological exam was consistent with Brown-Séquard syndrome. Magnetic resonance images showed a C5-6 herniated disc that was adjacent to the ossified ligament and indenting the cord. The mass was surrounded by cerebrospinal fluid signal intensity margin, and caudally the ventral dura line appears divided into two, consistent with the “Y-sign” described by Sasaji et al. Cord edema were noted. Because of preexisting canal stenosis and spinal cord at risk, a laminoplasty was performed, followed by an anterior C6 corpectomy. Spot-weld type adhesions of the posterior longitudinal ligament to the dura was noted, along with a longitudinal tear in the dura. An intradural extra-arachnoid fragment of herniated disc was removed. Clinical exam at 6 months after surgery revealed normal muscle strength but persistent mild paresthesias. It is difficult to make a definite diagnosis of intradural herniation preoperatively; however, the clinical findings and radiographic signs mentioned above are suggestive and should alert the surgeon to look for an intradural fragment. PMID:25295205

Wang, Dachuan; Wang, Haifeng; Shen, Wun-Jer

2014-01-01

128

Discriminating extrusive and bulging disk herniations by using serum hs CRP.  

PubMed

It has been proposed that because there is inflammation around the nerve roots in disk herniation, there might be an association between serum C Reactive Protein (CRP) with this disease. This study aimed to distinguish between two forms of disk herniation (extrusion, bulging) by comparing the level of serum high-sensitivity CRP (hs CRP). In this perspective study, a total of 62 candidates for lumbar disk herniation surgery were recruited in Tabriz Imam Reza Hospital from 2012 to 2013. The patients categorized in two groups; with extrusion (n = 34) and with bulging (n = 28). Pre-operative serum hs CRP was measured by turbidimetric immunoassay. Both extrusion and bulging groups were matched for their patients' sex (males: 61.8% vs. 57.1%, respectively; p = 0.71) and age (mean: 52.22 +/- 7.32 years vs. 49.69 +/- 9.40 years, respectively; p = 0.48). The mean serum hs CRP was significantly higher in the extrusion group (3.56 +/- 2.90 with a range of 0.1 to 19 mg dL(-1) vs. 0.74 +/- 0.91 with a range of 0 to 5 mg dL(-1); p < 0.001). Based on the results of the receiver operator characteristics (ROC) cure, a cut-off point of hs CRP was =2.6 was highly indicative of extrusion, with a sensitivity and specificity of 66 and 63%, respectively. Based on the findings of the present study, the mean serum hs CRP is significantly higher in the patients with extrusive disk herniation vs. those with bulging. The proposed cut-off point may be useful as a preliminary indicator of the type of herniation, before more detailed imaging becomes available. PMID:24511758

Talghini, S; Vahedi, Amir; Lotfinia, I

2013-11-01

129

Nucleus, Cytoplasm, Membrane  

NSDL National Science Digital Library

Explore the form and function of three of the most important cell parts -- the nucleus, cytoplasm, and membrane -- in this video segment adapted from Carolina Biological Supply's An Introduction to the Living Cell.

Foundation, Wgbh E.

2003-09-26

130

Naturally Occurring Disk Herniation in Dogs: An Opportunity for Pre-Clinical Spinal Cord Injury Research  

PubMed Central

Abstract Traumatic spinal cord injuries represent a significant source of morbidity in humans. Despite decades of research using experimental models of spinal cord injury to identify candidate therapeutics, there has been only limited progress toward translating beneficial findings to human spinal cord injury. Thoracolumbar intervertebral disk herniation is a naturally occurring disease that affects dogs and results in compressive/contusive spinal cord injury. Here we discuss aspects of this disease that are analogous to human spinal cord injury, including injury mechanisms, pathology, and metrics for determining outcomes. We address both the strengths and weaknesses of conducting pre-clinical research in these dogs, and include a review of studies that have utilized these animals to assess efficacy of candidate therapeutics. Finally, we consider a two-species approach to pre-clinical data acquisition, beginning with a reproducible model of spinal cord injury in the rodent as a tool for discovery with validation in pet dogs with intervertebral disk herniation. PMID:21438715

Levine, Gwendolyn J.; Porter, Brian F.; Topp, Kimberly; Noble-Haeusslein, Linda J.

2011-01-01

131

Incarcerated Thoracic Gastric Herniation after Nephrectomy: A Report of Two Cases  

PubMed Central

Iatrogenic diaphragmatic hernias can occur after abdominal or thoracic surgery. Acute presentation of a diaphragmatic hernia varies depending on the extent and nature of the organ which has herniated. The initial diagnosis can be challenging due to the nonspecific nature of the presenting symptoms. Delay in diagnosis poses a significant risk to the patient, and a rapid deterioration can occur in the context of strangulation. We outline two cases of acute gastric herniation through a defect in the diaphragm after an open and a laparoscopic nephrectomy. Both had characteristic findings on imaging, required emergency, surgery and had a successful outcome. Both cases highlight the potential for late presentation with non-specific symptoms and the necessity for urgent surgical management where gastric perfusion is compromised. PMID:23762738

Fitzgerald, Conall; Mc Cormack, Orla; Awan, Faisal; Elliott, Jessie; Ravi, Narayanasamy; Reynolds, John V.

2013-01-01

132

Patho-anatomy of Herniation of the Reticulum Through the Diaphragm in the Bovine  

PubMed Central

Dissection of embalmed and untreated water buffalo carcasses (n=10) revealed that hernias had occurred at the musculotendinous junction of the diaphragm, ventral to the foramen venae cavae and slightly lateral to the median plane. The diameter of the hernial ring varied from 7 cm to 20 cm. Herniation was more common in the right thoracic cavity with the reticulum firmly adherent to the hernia ring. Adhesions between the herniated portion of the reticulum and pleura, lung, pericardium or thoracic wall were present, while in a few cases thick fibrous tracts concealing metallic bodies were found. In two cases, involvement of esophageal groove with malalignment of cardia and reticulo-omasal opening was observed. Displacement and compression of the heart was observed in four animals. ImagesFigure 1.Figure 2.Figure 3. PMID:7340924

Deshpande, K. S.; Krishnamurthy, D.; Nigam, J. M.; Sharma, D. N.

1981-01-01

133

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

PubMed

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

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

2014-04-01

134

Effects of lumbar disk herniation on the careers of professional baseball players.  

PubMed

Outcomes after lumbar disk herniation in baseball athletes are currently unknown. It has been postulated that the repetitive torque-producing motions of a baseball player may have negative implications after a disk injury. Sixty-nine lumbar disk herniations (40 treated operatively, 29 nonoperatively) in 64 professional baseball players were identified, and important outcome measures including successful return to play, time to recovery, career longevity, and performance based on vital statistics to each position were documented. Ninety-seven percent of baseball athletes successfully returned to play at an average of 6.6 months after diagnosis. Athletes treated operatively required significantly more time to return to play than those managed nonoperatively (8.7 vs 3.6 months, respectively; P<.0001). PMID:22229920

Earhart, Jeffrey S; Roberts, David; Roc, Gilbert; Gryzlo, Stephen; Hsu, Wellington

2012-01-01

135

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

136

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

137

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

PubMed Central

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

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

2011-01-01

138

Sinking Skin Flaps, Paradoxical Herniation, and External Brain Tamponade: A Review of Decompressive Craniectomy Management  

Microsoft Academic Search

Decompressive craniectomy is reclaiming a role in neurocritical care. The altered pathophysiology found in a cranium converted\\u000a from a ‘closed’ box to an ‘open’ box’ carries benefits and risks. In some craniectomy patients, the forces of atmospheric\\u000a pressure and gravity overwhelm intracranial pressures, and the brain appears sunken. This can lead to paradoxical herniation\\u000a and the sinking skin flap syndrome,

Paul T. Akins; Kern H. Guppy

2008-01-01

139

Matrix mechanical properties of transversalis fascia in inguinal herniation as a model for tissue expansion.  

PubMed

Inguinal herniation represents a common condition requiring surgical intervention. Despite being regarded as a connective tissue disorder of uncertain cause, research has focused predominantly on biochemical changes in the key tissue layer, the transversalis fascia (TF) with little direct analysis of functional tissue mechanics. Connective tissue tensile properties are dominated by collagen fibril density and architecture. This study has correlated mechanical properties of herniated TF (HTF) and non-herniated TF (NHTF) with fibrillar properties at the ultrastructural level by quasi-static tensile mechanical analysis and image analysis of collagen electron micrographs. No significant difference was found between any of the key mechanical properties (break stress, strain or modulus) for HTF and NHTF. In addition, no significant differences were found in average collagen fibril diameter, density or fibre bundle spacing. However, both groups displayed anisotropy with greater break stress (p=0.001) on average in the transverse anatomical plane compared to the longitudinal plane in a mean ratio of 2:1 (anisotropy ratio), though there was no evidence of a difference in this ratio for HTF and NHTF for both break stress and modulus. It was noted that this anisotropy ratio corresponds closely with the expected force distribution on a model cylindrical structure loaded axially. The absence of other functional differences does not support the idea of a failing (injured) tissue but is consistent with it being a tissue undergoing chronic growth/expansion under multi-vectored mechanical loading. These findings provide new clues to collagen tissue herniation for mathematical modelling and model tissue engineering. PMID:19012890

Kureshi, Alvena; Vaiude, Partha; Nazhat, Showan N; Petrie, Aviva; Brown, Robert A

2008-12-01

140

Spontaneous intradural disc herniation with focal distension of the subarachnoid space in a dog  

PubMed Central

Myelo-computed tomography of a paraparetic 14-year-old dog revealed subarachnoid distension with an intradural filling defect above the T13–L1 disc space. T12–L1 hemilaminectomy followed by durotomy allowed removal of a large piece of degenerated disc material that compressed the spinal parenchyma. Full return to function was achieved 10 days post-surgery. The distension was likely secondary to the intradural herniation, and is a rare and distinct finding. PMID:23633713

Barnoon, Itai; Chai, Orit; Srugo, Itai; Peeri, Dana; Konstantin, Lilach; Brenner, Ori; Shamir, Merav H.

2012-01-01

141

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

PubMed Central

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

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

2012-01-01

142

Disc herniation in the thoracolumbar junction treated by minimally invasive transforaminal interbody fusion surgery.  

PubMed

Minimally invasive surgery-transforaminal lumbar interbody fusion (MIS-TLIF) has demonstrated efficacy in the treatment of lumbar degenerative diseases. Use of this procedure for thoracolumbar junction disc herniation remains challenging. Reports concerning MIS-TLIF at the thoracolumbar junction are rare. Thus, we performed a retrospective analysis of the clinical outcomes of 10 patients with thoracolumbar junction disc herniation treated by MIS-TLIF between December 2007 and October 2010. The purpose of this study was to investigate the efficacy and safety of MIS-TLIF for disc herniation in the thoracolumbar junction. Clinical and radiological data were collected and analyzed. Fusion levels included T12-L1 (two patients), L1-L2 (four patients) and L2-L3 (four patients). Clinical outcome was assessed using the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI). The average follow-up period was 39.2 months, with a minimum of 24 months. The mean ± standard error of the mean of the operative time, intraoperative blood loss, and x-ray exposure were 128 ± 36 minutes, 204 ± 35 mL, and 43 ± 12 seconds, respectively. The VAS for back and leg pain decreased significantly postoperatively from 6.4 ± 2.7 to 1.5 ± 0.6 (p<0.01), and from 7.1 ± 2.4 to 1.3 ± 0.4 (p<0.01) respectively, as did the ODI from 39.3 ± 11.2 to 16.5 ± 4.7 (p<0.01). Bone fusion was observed in eight patients. There were no other major complications at last follow-up. MIS-TIF is a safe and effective procedure for disc herniation in the thoracolumbar junction. Occurrence of non-union is relatively high compared to previous findings. PMID:24225365

Wang, Jian; Zhou, Yue; Zhang, Zheng Feng; Li, Chang Qing; Zheng, Wen Jie; Huang, Bo

2014-03-01

143

Apparent diffusion coefficient in normal and abnormal pattern of intervertebral lumbar discs: initial experience?  

PubMed Central

The aim of the present study was to compare the relationship of morphologically defined non-bulging/herniated, bulging and herniated intervertebral lumbar discs with quantitative apparent diffusion coefficient (ADC). Thirty-two healthy volunteers and 28 patients with back pain or sciatica were examined by MRI. All intervertebral lumbar discs from L1 to S1 were classified according to morphological abnormality and degenerated grades. The ADC values of nucleus pulposus (NP) were measured and recorded. The significant differences about mean ADC values of NP were found between non-bulging/herniated discs and bulging discs as well as herniated discs (P < 0.05), whereas there were no significant differences in ADC values between bulging and herniated discs (P > 0.05). Moreover, statistically significant relationship was found in the mean ADC values of NP between “non-bulging/herniated and non-degenerated discs” and “non-bulging/herniated degenerated discs” as well as herniated discs (P < 0.05). Linear regression analysis between ADC value and disc level revealed an inverse correlation (r = -0.18). The ADC map of the NP is a potentially useful tool for the quantitative assessment of componential and molecular alterations accompanied with lumbar disc abnormalities. PMID:23554690

Niu, Gang; Yu, Xuewen; Yang, Jian; Wang, Rong; Zhang, Shaojuan; Guo, Youmin

2011-01-01

144

Survival with good outcome after cerebral herniation and Duret hemorrhage caused by traumatic brain injury.  

PubMed

Brainstem hemorrhage can occur as a primary or secondary event in traumatic brain injury (TBI). Secondary brainstem hemorrhage that evolves from raised intracranial pressure and transtentorial herniation is referred to as Duret hemorrhage. Duret hemorrhage following TBI has been considered an irreversible and terminal event. The authors report on the case of a young adult patient with TBI who presented with a low Glasgow Coma Scale score and advanced signs of cerebral herniation. She underwent an urgent decompressive hemicraniectomy for evacuation of an acute epidural hematoma and developed a Duret hemorrhage postoperatively. In accordance with the family's wishes, aggressive TBI monitoring and treatment in the intensive care unit was continued even though the anticipated outcome was poor. After a lengthy hospital course, the patient improved dramatically and was discharged ambulatory, with good cognitive functioning and a Glasgow Outcome Scale score of 4. Duret hemorrhage secondary to raised intracranial pressure is not always a terminal event, and by itself should not trigger a decision to withdraw care. Aggressive intracranial monitoring and treatment of a Duret hemorrhage arising secondary to cerebral herniation may enable a good recovery in selected patients after severe TBI. PMID:19012479

Stiver, Shirley I; Gean, Alisa D; Manley, Geoffrey T

2009-06-01

145

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.

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

2014-01-01

146

Convergence of the nucleus-nucleus Glauber multiple scattering series  

SciTech Connect

The Glauber {ital S}-matrix operator for nucleus-nucleus scattering is expressed as a finite series of matrix elements involving Bell's polynomials. Analyzing {alpha}{sup 4}He elastic-scattering data at the incident momentum of 4.32 GeV/{ital c}, we infer that our expansion is appreciably converging. Further, by applying closure over target and projectile states and neglecting a certain class of terms involving intermediate excitations, we arrive at a recurrence relation for nucleus-nucleus multiple scattering series terms, which invites further study as it seems to provide a simple method for calculating the nucleus-nucleus elastic-scattering cross section.

Usmani, A.A.; Ahmad, I. (Department of Physics, Aligarh Muslim University, Aligarh 202 002, Uttar Pradesh, India (IN))

1991-05-01

147

Kaon-nucleus scattering  

NASA Technical Reports Server (NTRS)

The derivations of the Lippmann-Schwinger equation and Watson multiple scattering are given. A simple optical potential is found to be the first term of that series. The number density distribution models of the nucleus, harmonic well, and Woods-Saxon are used without t-matrix taken from the scattering experiments. The parameterized two-body inputs, which are kaon-nucleon total cross sections, elastic slope parameters, and the ratio of the real to the imaginary part of the forward elastic scattering amplitude, are presented. The eikonal approximation was chosen as our solution method to estimate the total and absorptive cross sections for the kaon-nucleus scattering.

Hong, Byungsik; Maung, Khin Maung; Wilson, John W.; Buck, Warren W.

1989-01-01

148

Subthreshold Antiproton Production in Nucleus-Nucleus Collisions  

E-print Network

Antiproton production in nucleus-nucleus collisions at energies below the threshold for its production from the nucleon-nucleon interaction in free space is studied in the relativistic Vlasov-Uehling-Uhlenbeck model. The antiproton self...

LI, GQ; Ko, Che Ming; Fang, X. S.; Zheng, Y. M.

1994-01-01

149

Radiographic Markers of Femoroacetabular Impingement: Correlation of Herniation Pit and Femoral Bump with a Positive Cross-Over Ratio  

PubMed Central

Introduction. The goal of this study was to research the association of femoral bumps and herniation pits with the overlap-ratio of the cross-over sign. Methods. Pelvic X-rays and CT-scans of 2925 patients with good assessment of the anterior and the posterior acetabular wall and absence of neutral pelvic tilt were enrolled in the investigation. Finally pelvic X-rays were assessed for the presence of a positive cross-over sign, and CT-scans for a femoral bump or a herniation pit. Additionally, if a positive cross-over sign was discovered, the overlap-ratio was calculated. Results. A femoral bump was found in 53.3% (n = 1559), and a herniation pit in 27.2% (n = 796) of all hips. The overlap-ratio correlated positively with the presence of a femoral bump, while a negative correlation between the overlap-ratio and the presence of a herniation pit was found. The latter was significantly more often combined with a femoral bump than without. Conclusions. We detected an increased prevalence of femoral bump with increasing overlap-ratios of the cross-over sign indicating a relation to biomechanical stress. The observed decreased prevalence of herniation pits with increasing overlap-ratios could be explained by reduced mechanical stress due to nontightened iliofemoral ligament in the presence of retroversion of the acetabulum. PMID:24876972

Scheyerer, Max J.; Copeland, Carol E.; Stromberg, Jeffrey; Ruckstuhl, Thomas; Werner, Clement M. L.

2014-01-01

150

Management of Chronic Pain of Cervical Disc Herniation and Radiculitis with Fluoroscopic Cervical Interlaminar Epidural Injections  

PubMed Central

Study Design: A randomized, double-blind, active controlled trial. Objective: To evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids in the management of chronic neck pain and upper extremity pain in patients with disc herniation and radiculitis. Summary of Background Data: Epidural injections in managing chronic neck and upper extremity pain are commonly employed interventions. However, their long-term effectiveness, indications, and medical necessity, of their use and their role in various pathologies responsible for persistent neck and upper extremity pain continue to be debated, even though, neck and upper extremity pain secondary to disc herniation and radiculitis, is described as the common indication. There is also paucity of high quality literature. Methods: One-hundred twenty patients were randomly assigned to one of 2 groups: Group I patients received cervical interlaminar epidural injections of local anesthetic (lidocaine 0.5%, 5 mL); Group II patients received 0.5% lidocaine, 4 mL, mixed with 1 mL of nonparticulate betamethasone. Primary outcome measure was ? 50 improvement in pain and function. Outcome assessments included Numeric Rating Scale (NRS), Oswestry Disability Index (ODI), opioid intake, employment, and changes in weight. Results: Significant pain relief and functional status improvement (? 50%) was demonstrated in 72% of patients who received local anesthetic only and 68% who received local anesthetic and steroids. In the successful group of participants, significant improvement was illustrated in 77% in local anesthetic group and 82% in local anesthetic with steroid group. Conclusions: Cervical interlaminar epidural injections with or without steroids may provide significant improvement in pain and function for patients with cervical disc herniation and radiculitis. PMID:22859902

Manchikanti, Laxmaiah; Cash, Kimberly A.; Pampati, Vidyasagar; Wargo, Bradley W.; Malla, Yogesh

2012-01-01

151

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

PubMed Central

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

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

2010-01-01

152

Transforaminal percutaneous endoscopic surgery for far lateral lumbar intervertebral disk herniation.  

PubMed

Far lateral lumbar intervertebral disk herniation (FLLIDH) most commonly occurs far lateral to the intervertebral facet at L3-L4 and L4-L5 and accounts for 3.8% of all lumbar disk herniations. Traditional surgery for FLLIDH involves massive surgical trauma, damage to the spinal structure, and instability of the lumbar spine. The goals of this study were to perform a systematic review of the literature and investigate the clinical outcomes of transforaminal percutaneous endoscopic surgery in the treatment of FLLIDH. Between October 2010 and May 2012, fifteen patients diagnosed with FLLIDH underwent transforaminal percutaneous endoscopic surgery at the authors' institution to remove the herniated disk and release the nerve root. Pain was measured pre- and postoperatively with a visual analog pain scale (VAS), and postoperative outcomes were evaluated using MacNab's criteria. A PubMed database search was conducted for the systematic review. Median operative time was 100 minutes (range, 80-140 minutes). Median volume of intraoperative blood loss was 20 mL (range, 10-50 mL). Patients were followed postoperatively for a median of 6 months (range, 1-12 months). MacNab's criteria rated 12 (80.0%) surgical outcomes as excellent, 2 (13.3%) as good, and 1 (6.7%) as fair. The systematic review included 14 studies. Transforaminal percutaneous endoscopic surgery appears to be a safe and effective minimally invasive procedure for treating FLLIDH. However, as demand for this type of surgery increases, the possibility of intraoperative aggravated leg pain and compression injury of the ganglion must be considered. PMID:25102508

Liao, Zhong; Chen, Wei; Wang, Chao-Hui

2014-08-01

153

Evolution of the nucleus.  

PubMed

The nucleus represents a major evolutionary transition. As a consequence of separating translation from transcription many new functions arose, which likely contributed to the remarkable success of eukaryotic cells. Here we will consider what has recently emerged on the evolutionary histories of several key aspects of nuclear biology; the nuclear pore complex, the lamina, centrosomes and evidence for prokaryotic origins of relevant players. PMID:24508984

Devos, Damien P; Gräf, Ralph; Field, Mark C

2014-06-01

154

Analytic optical potentials for nucleon-nucleus nucleus-nucleus collisions involving light and medium nuclei  

NASA Technical Reports Server (NTRS)

Utilizing an optical model potential approximation to the exact nucleus-nucleus multiple-scattering series, optical potentials for nucleon-nucleus and nucleus-nucleus collisions are analytically derived. These expressions are applicable to light and medium cosmic ray nuclei as their single-particle density distributions are analytically determined, without approximation, from their actual harmonic well charge density distributions. Pauli correlation effects are included through the use of a simple Gaussian function to replace the usual expression obtained in the infinite nuclear matter approximation.

Bidasaria, H. B.; Townsend, L. W.

1982-01-01

155

Leukocyte nucleus segmentation and nucleus lobe counting  

PubMed Central

Background Leukocytes play an important role in the human immune system. The family of leukocytes is comprised of lymphocytes, monocytes, eosinophils, basophils, and neutrophils. Any infection or acute stress may increase or decrease the number of leukocytes. An increased percentage of neutrophils may be caused by an acute infection, while an increased percentage of lymphocytes can be caused by a chronic bacterial infection. It is important to realize an abnormal variation in the leukocytes. The five types of leukocytes can be distinguished by their cytoplasmic granules, staining properties of the granules, size of cell, the proportion of the nuclear to the cytoplasmic material, and the type of nucleolar lobes. The number of lobes increased when leukemia, chronic nephritis, liver disease, cancer, sepsis, and vitamin B12 or folate deficiency occurred. Clinical neutrophil hypersegmentation has been widely used as an indicator of B12 or folate deficiency.Biomedical technologists can currently recognize abnormal leukocytes using human eyes. However, the quality and efficiency of diagnosis may be compromised due to the limitations of the biomedical technologists' eyesight, strength, and medical knowledge. Therefore, the development of an automatic leukocyte recognition system is feasible and necessary. It is essential to extract the leukocyte region from a blood smear image in order to develop an automatic leukocyte recognition system. The number of lobes increased when leukemia, chronic nephritis, liver disease, cancer, sepsis, and vitamin B12 or folate deficiency occurred. Clinical neutrophil hypersegmentation has been widely used as an indicator of B12 or folate deficiency. Results The purpose of this paper is to contribute an automatic leukocyte nuclei image segmentation method for such recognition technology. The other goal of this paper is to develop the method of counting the number of lobes in a cell nucleus. The experimental results demonstrated impressive segmentation accuracy. Conclusions Insensitive to the variance of images, the LNS (Leukocyte Nuclei Segmentation) method functioned well to isolate the leukocyte nuclei from a blood smear image with much better UR (Under Segmentation Rate), ER (Overall Error Rate), and RDE (Relative Distance Error). The presented LC (Lobe Counting) method is capable of splitting leukocyte nuclei into lobes. The experimental results illuminated that both methods can give expressive performances. In addition, three advanced image processing techniques were proposed as weighted Sobel operator, GDW (Gradient Direction Weight), and GBPD (Genetic-based Parameter Detector). PMID:21073711

2010-01-01

156

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

157

Treatment of localized neuropathic pain after disk herniation with 5% lidocaine medicated plaster  

PubMed Central

Objective To assess treatment with the 5% lidocaine medicated plaster for peripheral neuropathic pain after disk herniation. Study design Case series, single center, retrospective data. Patients and methods Data of 23 patients treated for neuropathic pain with the lidocaine plaster for up to 24 months after a protrusion or prolapse of the cervical, thoracic, or lumbar vertebral disks were retrospectively analyzed. Changes in overall pain intensity, in intensity of different pain qualities and of allodynia and hyperalgesia were evaluated. Results Patients (14 female/nine male, mean age 53.5 ± 10.4 years) presented with radiating pain into the abdomen, back, neck, shoulder, or legs and feet with a mean pain intensity of 8.3 ± 1.5 on the 11-point Likert scale. Mean treatment duration was 7.6 months; 52% of the patients received lidocaine plaster as monotherapy. At the end of the observation, mean overall pain intensity had been reduced to 3.1 ± 1.8. All other parameters also improved. The treatment was well tolerated. Conclusion These results point to a safe and effective treatment approach with 5% lidocaine medicated plaster for localized neuropathic pain related to disk herniation. However, owing to the small sample size, further investigation in a larger-scale controlled trial is warranted. PMID:22973116

Likar, Rudolf; Kager, Ingo; Obmann, Michael; Pipam, Wolfgang; Sittl, Reinhard

2012-01-01

158

Herniated near-term pregnancy through an incisional hernia treated with polypropylene mesh: A case report.  

PubMed

The management of a large incisional hernia amidst gravid uterus in its sac is a very challenging obstetric entity. Because of the uncommonness of this entity, there has not been any evidence-based guideline regarding the optimal mode of treatment and so treatment is largely individualised. We present the case of a 32-year-old booked G7P6+0 Nigerian woman with two living children who was already booked for elective repeat lower segment Caesarean section (CS) and 'Caesarean' herniorrhaphy at 38 weeks of gestation but only to present at 36-weeks gestation with a 4-hour history of labour pains. She had an emergency lower segment CS 2 years earlier due to obstructed labour but the CS was complicated by wound infection. Examination revealed gravid uterus that herniated through the incisional hernia. She subsequently had emergency lower segment CS with the repair of the hernia with polypropylene mesh. She had uneventful post-operative recovery. Herniated uterus of near-term pregnancy through an incisional hernia has not been reported in our hospital. As in our case, triumphant management required brave but multidisciplinary approach and currently there are emerging management options such as the use of mesh and laparoscopic technique. PMID:25013263

Uchenna, Eleje George; Chukwuneme, Okpala Boniface; Ejike, Enendu Stephen; Mbanefo, Okeke Paul; Benjamin, Ejikeme Toochukwu

2014-05-01

159

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

160

Herniated near-term pregnancy through an incisional hernia treated with polypropylene mesh: A case report  

PubMed Central

The management of a large incisional hernia amidst gravid uterus in its sac is a very challenging obstetric entity. Because of the uncommonness of this entity, there has not been any evidence-based guideline regarding the optimal mode of treatment and so treatment is largely individualised. We present the case of a 32-year-old booked G7P6+0 Nigerian woman with two living children who was already booked for elective repeat lower segment Caesarean section (CS) and ‘Caesarean’ herniorrhaphy at 38 weeks of gestation but only to present at 36-weeks gestation with a 4-hour history of labour pains. She had an emergency lower segment CS 2 years earlier due to obstructed labour but the CS was complicated by wound infection. Examination revealed gravid uterus that herniated through the incisional hernia. She subsequently had emergency lower segment CS with the repair of the hernia with polypropylene mesh. She had uneventful post-operative recovery. Herniated uterus of near-term pregnancy through an incisional hernia has not been reported in our hospital. As in our case, triumphant management required brave but multidisciplinary approach and currently there are emerging management options such as the use of mesh and laparoscopic technique. PMID:25013263

Uchenna, Eleje George; Chukwuneme, Okpala Boniface; Ejike, Enendu Stephen; Mbanefo, Okeke Paul; Benjamin, Ejikeme Toochukwu

2014-01-01

161

Nuclear rainbow scattering and nucleus-nucleus potential  

E-print Network

Elastic scattering of alpha-particle and some tightly-bound light nuclei has shown the pattern of rainbow scattering at medium energies, which is due to the refraction of the incident wave by a strongly attractive nucleus-nucleus potential. This review gives an introduction to the physics of the nuclear rainbow based essentially on the optical model description of the elastic scattering. Since the realistic nucleus-nucleus optical potential (OP) is the key to explore this interesting process, an overview of the main methods used to determine the nucleus-nucleus OP is presented. The refractive rainbow-like structures observed in other quasi-elastic scattering reactions have also been discussed. Some evidences for the refractive effect in the elastic scattering of unstable nuclei are presented and perspectives for the future studies are discussed.

Dao T. Khoa; W. von Oertzen; H. G. Bohlen; S. Ohkubo

2006-12-21

162

Neutrino-nucleus interactions  

SciTech Connect

The study of neutrino oscillations has necessitated a new generation of neutrino experiments that are exploring neutrino-nuclear scattering processes. We focus in particular on charged-current quasi-elastic scattering, a particularly important channel that has been extensively investigated both in the bubble-chamber era and by current experiments. Recent results have led to theoretical reexamination of this process. We review the standard picture of quasi-elastic scattering as developed in electron scattering, review and discuss experimental results, and discuss additional nuclear effects such as exchange currents and short-range correlations that may play a significant role in neutrino-nucleus scattering.

Gallagher, H.; /Tufts U.; Garvey, G.; /Los Alamos; Zeller, G.P.; /Fermilab

2011-01-01

163

Gatekeepers of the Nucleus  

NSDL National Science Digital Library

Nuclear pore complexes (NPCs) form the site for entry and exit from the nucleus. A convergence of studies have defined the physical framework for the nuclear transport mechanism. This includes definition of the soluble transport machinery required for protein and RNA movement, x-ray structure analysis of transport factors, definitive compositional analysis of yeast NPCs, and documentation of the relative steady state arrangement of NPC components within the portal. With this information, researchers are now in the exciting position to examine the dynamic interplay between shuttling transport factors and the static pore complex.

Susan Wente (Washington University School of Medicine;Department of Cell Biology and Physiology)

2000-05-26

164

Nucleus from String Theory  

E-print Network

In generic holographic QCD, we find that baryons are bound to form a nucleus, and that its radius obeys the empirically-known mass number (A) dependence r A^{1/3} for large A. Our result is robust, since we use only a generic property of D-brane actions in string theory. We also show that nucleons are bound completely in a finite volume. Furthermore, employing a concrete holographic model (derived by Hashimoto, Iizuka, and Yi, describing a multi-baryon system in the Sakai-Sugimoto model), the nuclear radius is evaluated as O(1) x A^{1/3} [fm], which is consistent with experiments.

Koji Hashimoto; Takeshi Morita

2011-03-29

165

Higgs-Boson Production in Nucleus-Nucleus Collisions  

NASA Technical Reports Server (NTRS)

Cross section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

Norbury, John W.

1992-01-01

166

Higgs-boson production in nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

Cross-section calculations are presented for the production of intermediate-mass Higgs bosons produced in ultrarelativistic nucleus-nucleus collisions via two-photon fusion. The calculations are performed in position space using Baur's method for folding together the Weizsacker-Williams virtual-photon spectra of the two colliding nuclei. It is found that two-photon fusion in nucleus-nucleus collisions is a plausible way of finding intermediate-mass Higgs bosons at the Superconducting Super Collider or the CERN Large Hadron Collider.

Norbury, J. W.; Townsend, L. W. (Principal Investigator)

1990-01-01

167

Lumbar disc herniation and cauda equina syndrome following spinal manipulative therapy: a review of six court decisions in Canada.  

PubMed

The purpose of this review is to expand practitioners' knowledge on areas of liability when treating low back pain patients. Six cases where chiropractors in Canada were sued for allegedly causing or aggravating lumbar disc herniation after spinal manipulative therapy were retrieved using the CANLII search database. The case series involves 4 men and 2 women with an average age of 37.3 years (range, 31-48 years). Trial courts' decisions were rendered between 2000 and 2011. This study highlights the following conclusions from Canadian courts: 1) informed consent is an ongoing process that cannot be entirely delegated to office personnel; 2) when the patient's history reveals risk factors for lumbar disc herniation the chiropractor has the duty to rule out disc pathology as an etiology for the symptoms presented by the patients before beginning anything but conservative palliative treatment; 3) lumbar disc herniation may be triggered by spinal manipulative therapy on vertebral segments distant from the involved herniated disc such as the thoracic spine. PMID:24485443

Boucher, Pierre; Robidoux, Sébastien

2014-02-01

168

Brain death due to fat embolism -- could moderate hypercapnia and prone position be blamed for the tonsillar herniation?  

PubMed Central

Fat embolism to the systemic circulation in polytrauma patients is very common. The fat embolism syndrome (FES), however, is a rare condition. We describe a case of traumatic femur fracture with FES that was presented as acute tonsillar herniation (coning) and brain death postoperatively. We believe that in this case the prone position and moderate hypercapnia contributed to the acute coning. PMID:23977867

Larsson, Anders

2013-01-01

169

A look into the nucleus  

NSDL National Science Digital Library

Opposing forces in the nucleus are many, but why doesn?t the nucleus blow apart? In this portion of a tutorial on particle physics, students read that although the positive protons repel each other, the much greater, residual strong force holds the nucleus intact. An analogy about the nucleus is presented both as text and in pictures. Here, protons are represented as a coiled spring and the residual strong force is represented as a thick rope. The strong rope surrounds the spring, holding it coiled tightly together. The stored energy in the spring is contained by the strong rope. Copyright 2005 Eisenhower National Clearinghouse

Group, Lawrence B.

2002-01-01

170

The suprachiasmatic nucleus of the domestic chicken, Gallus domesticus  

E-print Network

lateral anterior dorsolateral nucleus DLAlr rostrolateral dorsolateral nucleus DLAm medial anterior dorsolateral nucleus xiii DLAmc magnocellular anterior dorsolateral nucleus DLP posterior dorsolateral nucleus DMA anterior thalamic... lateral anterior dorsolateral nucleus DLAlr rostrolateral dorsolateral nucleus DLAm medial anterior dorsolateral nucleus xiii DLAmc magnocellular anterior dorsolateral nucleus DLP posterior dorsolateral nucleus DMA anterior thalamic...

Cantwell, Elizabeth Layne

2007-04-25

171

Electric quadrupole excitations in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

Calculations are presented for electric quadrupole excitations in relativistic nucleus-nucleus collisions. The theoretical results are compared to an extensive data set and it is found that electric quadrupole effects provide substantial corrections to cross sections, especially for heavier nuclei.

Norbury, John W.

1989-01-01

172

The Cochlear NucleusThe Cochlear Nucleus Maria E. Rubio  

E-print Network

. (Young and Oertel) #12;6/1/2010 2 The Cochlear Nucleus Gross Anatomy Pathways (afferents and efferents and hearing loss Cajal Rat Brain: Gross Anatomy Lateral view: dissection Ventral viewSuperior view Dorsal view Sectional Anatomy of the Cochlear Nucleus and Auditory Nerve Fibers Distribution AVCN DCN R t l Lateral view

Oliver, Douglas L.

173

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

174

Dorsal Extradural Lumbar Disc Herniation Causing Cauda Equina Syndrome : A Case Report and Review of Literature  

PubMed Central

A 73-year-old male presented with a rare dorsally sequestrated lumbar disc herniation manifesting as severe radiating pain in both leg, progressively worsening weakness in both lower extremities, and urinary incontinence, suggesting cauda equina syndrome. Magnetic resonance imaging suggested the sequestrated disc fragment located in the extradural space at the L4-L5 level had surrounded and compressed the dural sac from the lateral to dorsal sides. A bilateral decompressive laminectomy was performed under an operating microscope. A large extruded disc was found to have migrated from the ventral aspect, around the thecal sac, and into the dorsal aspect, which compressed the sac to the right. After removal of the disc fragment, his sciatica was relieved and the patient felt strength of lower extremity improved. PMID:20379476

Lee, Sang-Ho; Arbatti, Nikhil J.

2010-01-01

175

Comet Odyssey: Comet Nucleus Orbiter  

Microsoft Academic Search

Comet Odyssey is a comet nucleus orbiter mission, proposed to NASA's Discovery program in 2004. The goal of the mission is to completely characterize a cometary nucleus, both physically and compositionally, as can only be done during an extended rendezvous and not with a fast flyby. Comet Odyssey will launch in October 2009 on a Delta II 7925 and use

P. R. Weissman; W. D. Smythe; S. J. Spitz; D. E. Bernard; R. W. Bailey

2004-01-01

176

Vibrations of the Atomic Nucleus  

Microsoft Academic Search

Recently a richly varied spectrum of vibrations has been discovered in the nucleus of an atom. The study of the nuclear vibrations is proving to be a major source of information on the structure of the nucleus and on the forces that hold it together. So far six giant vibrational modes have been observed. They fall in two classes. The

George F. Bertsch

1983-01-01

177

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

Microsoft Academic Search

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

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

2008-01-01

178

Comparison of potential models of nucleus-nucleus bremsstrahlung  

NASA Astrophysics Data System (ADS)

At low photon energies, the potential models of nucleus-nucleus bremsstrahlung are based on electric transition multipole operators, which are derived either only from the nuclear current or only from the charge density by making the long-wavelength approximation and using the Siegert theorem. In the latter case, the bremsstrahlung matrix elements are divergent and some regularization techniques are used to obtain finite values for the bremsstrahlung cross sections. From an extension of the Siegert theorem, which is not based on the long-wavelength approximation, a new potential model of nucleus-nucleus bremsstrahlung is developed. Only convergent integrals are included in this approach. Formal links between bremsstrahlung cross sections obtained in these different models are made. Furthermore, three different ways to calculate the regularized matrix elements are discussed and criticized. Some prescriptions for a proper implementation of the regularization are deduced. A numerical comparison between the different models is done by applying them to the ? +? bremsstrahlung.

Dohet-Eraly, J.; Baye, D.

2014-09-01

179

Repair, regenerative and supportive therapies of the annulus fibrosus: achievements and challenges  

PubMed Central

Lumbar discectomy is a very effective therapy for neurological decompression in patients suffering from sciatica due to hernia nuclei pulposus. However, high recurrence rates and persisting post-operative low back pain in these patients require serious attention. In the past decade, tissue engineering strategies have been developed mainly targeted to the regeneration of the nucleus pulposus (NP) of the intervertebral disc. Accompanying techniques that deal with the damaged annulus fibrous are now increasingly recognised as mandatory in order to prevent re-herniation to increase the potential of NP repair and to confine NP replacement therapies. In the current review, the requirements, achievements and challenges in this quickly emerging field of research are discussed. PMID:19104850

Bron, Johannes Leendert; Helder, Marco N.; Meisel, Hans-Jorg; Van Royen, Barend J.

2008-01-01

180

Repair, regenerative and supportive therapies of the annulus fibrosus: achievements and challenges.  

PubMed

Lumbar discectomy is a very effective therapy for neurological decompression in patients suffering from sciatica due to hernia nuclei pulposus. However, high recurrence rates and persisting post-operative low back pain in these patients require serious attention. In the past decade, tissue engineering strategies have been developed mainly targeted to the regeneration of the nucleus pulposus (NP) of the intervertebral disc. Accompanying techniques that deal with the damaged annulus fibrous are now increasingly recognised as mandatory in order to prevent re-herniation to increase the potential of NP repair and to confine NP replacement therapies. In the current review, the requirements, achievements and challenges in this quickly emerging field of research are discussed. PMID:19104850

Bron, Johannes Leendert; Helder, Marco N; Meisel, Hans-Jorg; Van Royen, Barend J; Smit, Theodoor H

2009-03-01

181

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

182

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

PubMed Central

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

2014-01-01

183

Learning curve of full-endoscopic technique through interlaminar approach for l5/s1 disk herniations.  

PubMed

Although minimally invasive full-endoscopic (FE) spine surgery through the interlaminar approach has proved safe and effective for surgical treatment of lumbar disk herniation, the learning curve of the procedure has not been sufficiently established. The purpose of this study is to determine the learning curve for the FE surgery through interlaminar approach for treating the L5/S1 disk herniation. Thirty-six patients with lumbar disk herniation (L5/S1 segment) who underwent FE lumbar discectomy through the interlaminar approach between March 2011 and March 2012 were equally divided into Group A, B, and C by the study time of the surgeons. Clinical evaluation data included perioperative parameters (operative duration, intraoperative blood loss, and the amount of intraoperative bone and ligament excision), clinical curative effect index [visual analog scale (VAS) score for leg and back pain], complications, and the rate of conversion to open surgery. The operation duration, intraoperative bleeding, and the amount of bone and ligament excision were gradually and significantly reduced in the Groups A, B, and C (P < 0.01) and reflected in steep curves of proficiency suggesting that the rate of learning was fast. The VAS scores of leg and back pain were significantly improved (P < 0.01) and no symptomatic recurrence was noticed during the follow-up period (1-1.5 years). The outcomes the three groups were not significantly different. The clinical outcomes of the minimally invasive surgery for the treatment of L5/S1 segment disk herniation through the interlaminar approach were excellent suggesting of a satisfactory curative effect. The steep learning curves of perioperative parameters plotted against the number of surgeries conducted suggest that proficiency can be reached reasonably fast. PMID:24839114

Xu, Haidong; Liu, Xiaozhou; Liu, Gang; Zhao, Jiangning; Fu, Qiang; Xu, Bin

2014-11-01

184

Spontaneous migration of a redundant nerve root accompanied by absorption of lumbar disk herniation. A case report.  

PubMed

A redundant nerve root is defined as a large, elongated and tortuous nerve root commonly associated with severe lumbar spinal canal stenosis. Elongation of nerve roots as a result of mechanical trapping at stenotic level is assumed to be a possible mechanism. Here we present a case in a patient who showed a redundant nerve root above the level of a lumbar canal stenosis caused by disk herniation and redundancy spontaneously migrating to a lower lumbar stenosis level accompanied by absorption of the herniated disk as shown by magnetic resonance imaging (MRI). A 67-year-old Japanese woman presented with bilateral thigh/leg pain and intermittent claudication. A midsagittal T2-weighted MR image of the lumbar spine revealed severe spinal canal stenosis at the L3-4 and L4-5 levels. At the L3-4 level, central disk herniation compressed the dural tube. An MR image revealed redundant nerve roots just cranial to the severely compressed L3-4 level. A follow-up MRI study revealed regression of disk herniation at the L3-4 level. In contrast, there was no significant change of the stenosis at the L4-5 level. Sagittal T2-weighted MR imaging at follow-up revealed redundant nerve roots just cranial to the L4-5 level, whereas the redundant nerve roots cranial to the L3-4 level had disappeared. The MRI findings of the present case support the "squeeze" hypothesis as causative of redundant nerve roots. PMID:24029099

Koda, M; Rokkaku, T; Mannoji, C; Okamoto, Y; Kon, T; Murakami, M; Furuya, T; Yamazaki, M

2012-11-01

185

Sensitivity of cross sections for elastic nucleus-nucleus scattering to halo nucleus density distributions  

SciTech Connect

In order to clear up the sensitivity of the nucleus-nucleus scattering to the nuclear matter distributions in exotic halo nuclei, we have calculated differential cross sections for elastic scattering of the {sup 6}He and {sup 11}Li nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon with different assumed nuclear density distributions in {sup 6}He and {sup 11}Li.

Alkhazov, G. D.; Sarantsev, V. V., E-mail: saran@pnpi.spb.ru [Petersburg Nuclear Physics Institute NRC KI (Russian Federation)

2012-12-15

186

Toward a systematic nucleus-nucleus potential for peripheral collisions  

NASA Astrophysics Data System (ADS)

A systematic nucleus-nucleus potential is proposed based on an optical model analysis of angular distributions of differential cross sections of 6Li and 7Li elastic scattering from targets with A?40 with incident energies between 5 and 40 MeV/nucleon. A single-folding model based on the Bruyères Jeukenne-Lejeune-Mahaux (JLMB) model nucleon-nucleus potentials was used. Systematics in energy dependence of the potential parameters were obtained. This systematics was found to give reasonable account for both elastic scattering and total reaction cross sections for projectiles with mass numbers up to A˜40, including both stable and unstable nuclei, for incident energies from the vicinity of the Coulomb barrier to about 100 MeV/nucleon.

Xu, Y. P.; Pang, D. Y.

2013-04-01

187

Atom as a "Dressed" Nucleus  

E-print Network

It is shown that the electrostatic potential of atomic nucleus "seen" by a fast charged projectile at short distances is smeared quantum mechanically due to nucleus motion around the atomic center of inertia. For example, the "positive charge cloud" size in the Hydrogen ground state is much larger than the proper proton size. It is even bigger for the target atoms in excited initial states. The elastic scattering at large angles is generally weaker than the Rutherford one since the effective potential at short distances is softer than the Colombian one due to a natural "cutoff". In addition, the large angle scattering leads to the target atom excitations due to pushing the nucleus (=> inelastic processes). The Rutherford cross section is in fact the inclusive rather than the elastic one. These results are analogous to the QED ones. The difference and the value of presented below non relativistic atomic calculations is in non perturbatively (exact) nucleus "dressing" that immediately leads to correct physical results and to significant technical simplifications. In these respects the nucleus bound in an atom is a simple but a rather realistic model of a "dressed" charge in the QFT. This idea is briefly demonstrated on the real electron model (electronium) that is made free from infinities.

Vladimir Kalitvianski

2008-06-16

188

Cometary nucleus and active regions  

NASA Technical Reports Server (NTRS)

On the basis of the icy conglomerate model of cometary nuclei, various observations demonstrate the spotted nature of many or most nuclei, i.e., regions of unusual activity, either high or low. Rotation periods, spin axes and even precession of the axes are determined. The observational evidence for variations in activity over the surfaces of cometary nuclei are listed and discussed. On June 11 the comet IRAS-ARAKI-ALCOCK approached the Earth to a distance of 0.031 AU, the nearest since C/Lexell, 1770 I, providing a unique opportunity for near-nucleus observations. Preliminary analysis of these images establishes the spin axis of the nucleus, with an oblioquity to the orbit plane of approximately 50 deg, and a lag angle of sublimation approximately 35 deg from the solar meridian on the nucleus. Asymmetries of the inner coma suggests a crazy-quilt distribution of ices with differing volatility over the surface of the nucleus. The observations of Comet P/Homes 1892 III, exhibiting two 8-10 magnitude bursts, are carefully analyzed. The grazing encounter produced, besides the first great burst, an active area on the nucleus, which was rotating retrograde with a period of 16.3hr and inclination nearly 180 deg. After the first burst the total magnitude fell less than two magnitudes from November 7 to November 30 (barely naked eye) while the nuclear region remained diffuse or complex, rarely if ever showing a stellar appearance. The fading was much more rapid after the second burst. The grazing encounter distributed a volume of large chunks in the neighborhood of the nucleus, maintaining activity for weeks.

Whipple, F. L.

1984-01-01

189

Guideline update for the performance of fusion procedures for degenerative disease of the lumbar spine. Part 8: lumbar fusion for disc herniation and radiculopathy.  

PubMed

Patients suffering from a lumbar herniated disc will typically present with signs and symptoms consistent with radiculopathy. They may also have low-back pain, however, and the source of this pain is less certain, as it may be from the degenerative process that led to the herniation. The surgical alternative of choice remains a lumbar discectomy, but fusions have been performed for both primary and recurrent disc herniations. In the original guidelines, the inclusion of a fusion for routine discectomies was not recommended. This recommendation continues to be supported by more recent evidence. Based on low-level evidence, the incorporation of a lumbar fusion may be considered an option when a herniation is associated with evidence of spinal instability, chronic low-back pain, and/or severe degenerative changes, or if the patient participates in heavy manual labor. For recurrent disc herniations, there is low-level evidence to support the inclusion of lumbar fusion for patients with evidence of instability or chronic low-back pain. PMID:24980585

Wang, Jeffrey C; Dailey, Andrew T; Mummaneni, Praveen V; Ghogawala, Zoher; Resnick, Daniel K; Watters, William C; Groff, Michael W; Choudhri, Tanvir F; Eck, Jason C; Sharan, Alok; Dhall, Sanjay S; Kaiser, Michael G

2014-07-01

190

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

PubMed Central

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

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

2010-01-01

191

Do preoperative fear avoidance model factors predict outcomes after lumbar disc herniation surgery? A systematic review  

PubMed Central

Background Lumbar disc herniation (LDH) surgery is usually recommended when conservative treatments fail to manage patients’ symptoms. However, many patients undergoing LDH surgery continue to report pain and disability. Preoperative psychological factors have shown to be predictive for postoperative outcomes. Our aim was to systematically review studies that prospectively examined the prognostic value of factors in the Fear Avoidance Model (FAM), including back pain, leg pain, catastrophizing, anxiety, fear-avoidance, depression, physical activity and disability, to predict postoperative outcomes in patients undergoing LDH surgery. Methods We performed a systematic literature review of prospective studies that measured any FAM factors preoperatively to predict postoperative outcomes for patients undergoing LDH surgery. Our search databases included PubMed, CINAHL, and PsycINFO. We assessed the quality of each included study using a certain quality assessment list. Degree of agreement between reviewers on quality assessment was examined. Results related to FAM factors in the included studies were summarized. Results Thirteen prospective studies met our inclusion criteria. Most studies were considered high quality. Heterogeneity was present between the included studies in many aspects. The most common FAM factors examinered were baseline pain, disability and depression. In, general, depression, fear-avoidance behaviors, passive pain coping, and anxiety FAM factors appeared to have negative influence on LDH surgical outcome. Baseline back pain and leg pain appeared to have differing prognostic value on LDH surgical outcomes. Conclusions FAM factors seem to influence LDH surgical outcomes. Patients with high levels of depression, anxiety and fear-avoidance behaviors are more likely to have poor outcomes following LDH surgery. Conversely, high levels of leg pain, but not back pain seem to be predictor for favorable LDH surgery outcome. More research is needed to determine the exact role of FAM factors on LDH surgical outcome and the value for screening for these factors. PMID:24237581

2013-01-01

192

Fluoroscopic caudal epidural injections in managing chronic axial low back pain without disc herniation, radiculitis, or facet joint pain  

PubMed Central

Background Chronic low back pain without disc herniation is common. Various modalities of treatments are utilized in managing this condition, including epidural injections. However, there is continued debate on the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections. Methods A randomized, double-blind, actively controlled trial was conducted. The objective was to evaluate the ability to assess the effectiveness of caudal epidural injections of local anesthetic with or without steroids for managing chronic low back pain not caused by disc herniation, radiculitis, facet joints, or sacroiliac joints. A total of 120 patients were randomized to two groups; one group did not receive steroids (group 1) and the other group did (group 2). There were 60 patients in each group. The primary outcome measure was at least 50% improvement in Numeric Rating Scale and Oswestry Disability Index. Secondary outcome measures were employment status and opioid intake. These measures were assessed at 3, 6, 12, 18, and 24 months after treatment. Results Significant pain relief and functional status improvement (primary outcome) defined as a 50% or more reduction in scores from baseline, were observed in 54% of patients in group 1 and 60% of patients in group 2 at 24 months. In contrast, 84% of patients in group 1 and 73% in group 2 saw significant pain relief and functional status improvement in the successful groups at 24 months. Conclusion Caudal epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and/or radiculitis. PMID:23091395

Manchikanti, Laxmaiah; Cash, Kimberly A; McManus, Carla D; Pampati, Vidyasagar

2012-01-01

193

Schmorl's nodes: current pathophysiological, diagnostic, and therapeutic paradigms.  

PubMed

Schmorl's nodes were first described by the pathologist Christian Schmorl in 1927 as a herniation of the nucleus pulposus through the cartilaginous and bony endplate into the vertebral body. Although such lesions present most commonly as incidental findings in asymptomatic patients (or in patients with back or radicular pain due to other etiology), there have been several reports emphasizing the deleterious effects of the inflammatory response and endplate changes elicited by the herniation of for such reasons, Schmorl's nodes have been occasionally implicated in the etiology of chronic axial pain as well as in pathological osteoporotic fractures. In this article, a thorough literature review about the most relevant historical studies on Schmorl's nodes previously published is performed. Furthermore, the authors provide an overview about the recent advances in basic science research on the pathophysiology of such lesions, as well as on current diagnostic and therapeutic paradigms. PMID:23955279

Mattei, Tobias A; Rehman, Azeem A

2014-01-01

194

Single nucleon emission in relativistic nucleus-nucleus reactions  

NASA Technical Reports Server (NTRS)

Significant discrepancies between theory and experiment have previously been noted for nucleon emission via electromagnetic processes in relativistic nucleus-nucleus collisions. The present work investigates the hypothesis that these discrepancies have arisen due to uncertainties about how to deduce the experimental electromagnetic cross section from the total measured cross section. An optical-model calculation of single neutron removal is added to electromagnetic cross sections and compared to the total experimental cross sections. Good agreement is found thereby resolving some of the earlier noted discrepancies. A detailed comparison to the recent work of Benesh, Cook, and Vary is made for both the impact parameter and the nuclear cross section. Good agreement is obtained giving an independent confirmation of the parameterized formulas developed by those authors.

Norbury, John W.; Townsend, Lawrence W.

1992-01-01

195

Analysis of relativistic nucleus-nucleus interactions in emulsion chambers  

NASA Technical Reports Server (NTRS)

The development of a computer-assisted method is reported for the determination of the angular distribution data for secondary particles produced in relativistic nucleus-nucleus collisions in emulsions. The method is applied to emulsion detectors that were placed in a constant, uniform magnetic field and exposed to beams of 60 and 200 GeV/nucleon O-16 ions at the Super Proton Synchrotron (SPS) of the European Center for Nuclear Research (CERN). Linear regression analysis is used to determine the azimuthal and polar emission angles from measured track coordinate data. The software, written in BASIC, is designed to be machine independent, and adaptable to an automated system for acquiring the track coordinates. The fitting algorithm is deterministic, and takes into account the experimental uncertainty in the measured points. Further, a procedure for using the track data to estimate the linear momenta of the charged particles observed in the detectors is included.

Mcguire, Stephen C.

1987-01-01

196

Transverse Energy in nucleus-nucleus collisions: A review  

SciTech Connect

The status of Transverse Energy (E/sub T/) in relativistic nucleus-nucleus collisions at the Brookhaven AGS and the CERN SPS is reviewed. The definition of E/sub T/ and its physical significance are discussed. The basic techniques and limitations of the experimental measurements are presented. The acceptances of the major experiments to be discussed are shown, along with remarks about their idiosyncrasies. The data demonstrate that the nuclear geometry of colliding spheres primarily determines the shapes of the observed spectra. Careful account of the acceptances is crucial to comparing and interpreting results. It is concluded that nuclear stopping power is high, and that the amount of energy deposited into the interaction volume is increasing with beam energy even at SPS energies. The energy densities believed to be obtained at the SPS are close to the critical values predicted for the onset of a quark-gluon plasma. 25 refs., 8 figs.

Tincknell, M.

1988-11-15

197

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

PubMed Central

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

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

2013-01-01

198

Minimum Two-Year Follow-Up of Cases with Recurrent Disc Herniation Treated with Microdiscectomy and Posterior Dynamic Transpedicular Stabilisation  

PubMed Central

The objective of this article is to evaluate two-year clinical and radiological follow-up results for patients who were treated with microdiscectomy and posterior dynamic transpedicular stabilisation (PDTS) due to recurrent disc herniation. This article is a prospective clinical study. We conducted microdiscectomy and PDTS (using a cosmic dynamic screw-rod system) in 40 cases (23 males, 17 females) with a diagnosis of recurrent disc herniation. Mean age of included patients was 48.92 ± 12.18 years (range: 21-73 years). Patients were clinically and radiologically evaluated for follow-up for at least two years. Patients’ postoperative clinical results and radiological outcomes were evaluated during the 3rd, 12th, and 24th months after surgery. Forty patients who underwent microdiscectomy and PDTS were followed for a mean of 41 months (range: 24-63 months). Both the Oswestry and VAS scores showed significant improvements two years postoperatively in comparison to preoperative scores (p<0.01). There were no significant differences between any of the three measured radiological parameters (?, LL, IVS) after two years of follow-up (p > 0.05). New recurrent disc herniations were not observed during follow-up in any of the patients. We observed complications in two patients. Performing microdiscectomy and PDTS after recurrent disc herniation can decrease the risk of postoperative segmental instability. This approach reduces the frequency of failed back syndrome with low back pain and sciatica. PMID:20448822

Kaner, Tuncay; Sasani, Mehdi; Oktenoglu, Tunc; Aydin, Ahmet Levent; Ozer, Ali Fahir

2010-01-01

199

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.

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

2014-01-01

200

Comet nucleus sample return mission  

NASA Technical Reports Server (NTRS)

A comet nucleus sample return mission in terms of its relevant science objectives, candidate mission concepts, key design/technology requirements, and programmatic issues is discussed. The primary objective was to collect a sample of undisturbed comet material from beneath the surface of an active comet and to preserve its chemical and, if possible, its physical integrity and return it to Earth in a minimally altered state. The secondary objectives are to: (1) characterize the comet to a level consistent with a rendezvous mission; (2) monitor the comet dynamics through perihelion and aphelion with a long lived lander; and (3) determine the subsurface properties of the nucleus in an area local to the sampled core. A set of candidate comets is discussed. The hazards which the spacecraft would encounter in the vicinity of the comet are also discussed. The encounter strategy, the sampling hardware, the thermal control of the pristine comet material during the return to Earth, and the flight performance of various spacecraft systems and the cost estimates of such a mission are presented.

1983-01-01

201

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

202

Theoretical antideuteron-nucleus absorptive cross sections  

NASA Technical Reports Server (NTRS)

Antideuteron-nucleus absorptive cross sections for intermediate to high energies are calculated using an ion-ion optical model. Good agreement with experiment (within 15 percent) is obtained in this same model for (bar p)-nucleus cross sections at laboratory energies up to 15 GeV. We describe a technique for estimating antinucleus-nucleus cross sections from NN data and suggest that further cosmic ray studies to search for antideuterons and other antinuclei be undertaken.

Buck, W. W.; Norbury, J. W.; Townsend, L. W.; Wilson, J. W.

1993-01-01

203

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

PubMed Central

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

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

2014-01-01

204

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

PubMed

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

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

2014-01-01

205

The nature of the cometary nucleus  

NASA Technical Reports Server (NTRS)

The basic properties of the cometary nucleus are reviewed. Consideration is given to the absence of depth differentiation, the icy conglomerate nature, the possible existence of a halo of icy grains around the nuclear region, the nucleus size and albedo, the mass, the rotation rate, and the chemical composition (elemental and molecular).

Delsemme, A. H.

1985-01-01

206

Actomyosin contractility rotates the cell nucleus  

PubMed Central

The cell nucleus functions amidst active cytoskeletal filaments, but its response to their contractile stresses is largely unexplored. We study the dynamics of the nuclei of single fibroblasts, with cell migration suppressed by plating onto micro-fabricated patterns. We find the nucleus undergoes noisy but coherent rotational motion. We account for this observation through a hydrodynamic approach, treating the nucleus as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and coherence of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be an intrinsic property of cells. PMID:24445418

Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G. V.

2014-01-01

207

Actomyosin contractility rotates the cell nucleus  

NASA Astrophysics Data System (ADS)

The cell nucleus functions amidst active cytoskeletal filaments, but its response to their contractile stresses is largely unexplored. We study the dynamics of the nuclei of single fibroblasts, with cell migration suppressed by plating onto micro-fabricated patterns. We find the nucleus undergoes noisy but coherent rotational motion. We account for this observation through a hydrodynamic approach, treating the nucleus as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and coherence of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be an intrinsic property of cells.

Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G. V.

2014-01-01

208

Experimental studies on the effect of chymopapain on nerve root compression caused by intervertebral disk material.  

PubMed

Chymopapain degrades the nucleus pulposus portion of the intervertebral disk of rabbits. The degradation is not grossly visible until 15 days post-injection. Depolymerization of the chondromucoprotein and decreases in the ability of a disk to imbibe fluid, is, in effect, a "chemical decompression" of the nucleur pulposus. The enzyme must come into direct contact with the chondromucoprotein complex of the disk material, and to a significant extent also must reach the area of disk material adjacent to the herniated annulus. Rapid depolymerization of the chondromucoprotein complex on a biomechanical level, and "decompression" of disk material on a biomechanical level can be correlated with relief of pain in all types of disk herniation in human beings. A primary biochemical change in the disk material would lead to a secondary decrease in inflammation if the change led to a "decompression" of the chondromucoprotein. Since the primary effect of chymopapain is on the chondromucoprotein of the disk, beneficial results would not be expected if nerve root compression is due to bony impingement or scar tissue following previous surgery. Chymopapain did not seem to possess any anti-inflammatory properties when bone was used as an irritant under a nerve root. However, this was technically difficult to evaluate and the possibility that chymopapain may also interfere with a chemical mediator of pain or interfere directly with an inflammatory reaction secondary to root compression can not be excluded. PMID:1126086

Krempen, J F; Minnig, D I; Smith, B S

1975-01-01

209

Membrane Properties and Neural Circuits of the Suprachiasmatic Nucleus.  

National Technical Information Service (NTIS)

The goal of these studies was to examine local synaptic circuits in the suprachiasmatic nucleus and the effect of GABA on suprachiasmatic nucleus neurons. Electrophysiological evidence was provided to support the hypothesis that suprachiasmatic nucleus ne...

E. F. Dudek, J. E. Rash, T. Yasumura, G. J. Strecker, B. N. Smith

1999-01-01

210

Afferents to the ventrolateral preoptic nucleus.  

PubMed

Sleep is influenced by diverse factors such as circadian time, affective states, ambient temperature, pain, etc., but pathways mediating these influences are unknown. To identify pathways that may influence sleep, we examined afferents to the ventrolateral preoptic nucleus (VLPO), an area critically implicated in promoting sleep. Injections of the retrograde tracer cholera toxin B subunit (CTB) into the VLPO produced modest numbers of CTB-labeled monoaminergic neurons in the tuberomammillary nucleus, raphe nuclei, and ventrolateral medulla, as well as a few neurons in the locus coeruleus. Immunohistochemistry for monoaminergic markers showed dense innervation of the VLPO by histaminergic, noradrenergic, and serotonergic fibers. Along with previous findings, these results suggest that the VLPO and monoaminergic nuclei may be reciprocally connected. Retrograde and anterograde tracing showed moderate or heavy inputs to the VLPO from hypothalamic regions including the median preoptic nucleus, lateral hypothalamic area, and dorsomedial hypothalamic nucleus (DMH), autonomic regions including the infralimbic cortex and parabrachial nucleus, and limbic regions including the lateral septal nucleus and ventral subiculum. Light to moderate inputs arose from orexin and melanin concentrating hormone neurons, but cholinergic or dopaminergic inputs were extremely sparse. Suprachiasmatic nucleus (SCN) projections to the VLPO were sparse, but the heavy input to the VLPO from the DMH, which receives direct and indirect SCN inputs, could provide an alternate pathway regulating the circadian timing of sleep. These robust pathways suggest candidate mechanisms by which sleep may be influenced by brain systems regulating arousal, autonomic, limbic, and circadian functions. PMID:11826126

Chou, Thomas C; Bjorkum, Alvhild A; Gaus, Stephanie E; Lu, Jun; Scammell, Thomas E; Saper, Clifford B

2002-02-01

211

Expression of Matrix Metalloproteinases is Positively Related to the Severity of Disc Degeneration and Growing Age in the East Asian Lumbar Disc Herniation Patients.  

PubMed

Matrix metalloproteinases (MMPs) have been known to play a pivotal role in the age- and/or disease-related degradation of intervertebral discs. We aimed to explore as to whether the expression of these enzymes is correlated to disc degeneration caused by increasing age and severity of herniation in the East Asian population. Thus, we studied the expressions of MMP-1 (collagenase), MMP-2 (gelatinase) and MMP-14 (membrane-type protease) in 65 patients diagnosed with lumbar disc herniation. The patients were divided into 3 groups according to their age, and the severity of herniation was graded on the basis of magnetic resonance imaging (MRI). Immunohistochemistry analysis was conducted to determine the expression of different MMPs in the post-surgery disc specimens. The results showed that expressions of these three enzymes were directly and positively related to the degree of disc degradation. Whereas, the MMP-1 expression was found to be elevated with the increasing age, the MMP-2 and MMP-14 remained unchanged in groups of different ages. A direct correlation between the expressions of MMP-2 and MMP-14 suggested a role of MMP-14 in the modulation of MMP-2 expression. PMID:24874308

Xu, Haidong; Mei, Qiang; Xu, Bin; Liu, Gang; Zhao, Jianning

2014-11-01

212

Chiropractic management using Cox cervical flexion-distraction technique for a disk herniation with left foraminal narrowing in a 64-year-old man  

PubMed Central

Objective The purpose of this case report is to describe chiropractic management of a patient with a C6/C7 left posteromedial disk herniation with foraminal narrowing and concomitant neurological compromise in the form of left upper extremity radiating pain and hypoesthesia/anesthesia using Cox flexion-distraction technique. Clinical Features A 64-year-old man presented to a chiropractic clinic with complaints of neck/left shoulder pain and hypoesthesia/anesthesia into the palmar side of his left hand. Magnetic resonance images of the cervical spine revealed a left posteromedial C6/C7 disk herniation along with foraminal narrowing. In addition, there were other levels of degeneration, most noted at the C3/C4 spinal level, which also had significant left-sided foraminal narrowing. Intervention and Outcome Treatment included Cox flexion-distraction protocols aimed to reduce nerve root compression along with supportive physiological therapeutic interventions to aid with pain reduction and functional improvement. The patient was treated a total of 10 times over a course of 4 weeks. The patient reported being pain-free and fully functional 8 months following the conclusion of care. Conclusion This case study demonstrated the use of Cox flexion-distraction for treatment of a patient with a cervical disk herniation, foraminal narrowing, and associated radiating pain and radiculopathy in the left upper extremity. PMID:22654692

Manison, Allen M.

2011-01-01

213

Anomalous anapole moment of an exotic nucleus  

E-print Network

Using the information on the nuclear structure of exotic neutron-rich halo nucleus $^{11}$Be, we evaluate the parity violating anapole moment in its ground state. The resulting value $\\kappa(^{11}$Be)$=0.17$ is fifteen times bigger than the typical value of the anapole moment of a normal nucleus of the same mass, and in fact exceeds by few times anapole moments of any known neutron-odd nuclei (e.g., kappa(^{11}Be) > 2|\\kappa(^{207}Pb)|. It is also few times bigger than the neutral current contribution to the lepton-nucleus interaction.

M. S. Hussein; A. F. R. de Toledo Piza; O. K. Vorov; A. K. Kerman

2001-12-31

214

The nucleus of Comet P/Encke  

NASA Astrophysics Data System (ADS)

The present CCD images and spectra of P/Encke near its aphelion during August-September 1988 indicates the cyclic character of the comet's brightness variation about a mean apparent red magnitude, with a photometric range of 0.62 + or - 0.04 mag. An aspherical rotating nucleus is judged to be consistent with (1) the observed cyclic variations, (2) the conformity of photometry with the inverse-square law, and (3) the absence of a resolvable coma. CCD spectra of the nucleus show a reddened continuum, in conjunction with a reflectivity gradient smaller than that of the nucleus of P/Tempel 2.

Luu, J.; Jewitt, D.

1990-07-01

215

Critical nucleus composition in a multicomponent system.  

PubMed

The properties of a critical nucleus are derived using the capillarity theory in the framework of classical nucleation. An analytical solution for the composition of a critical nucleus is given for low supersaturation. The theory is valid for any multicomponent systems. It is found that the deviation in nucleus composition from the equilibrium tie-line is mainly due to the difference in the Hessian of the Gibbs energy of the phases and the magnitude of the deviation in composition from equilibrium is order of the supersaturation. Despite our analysis strictly holds for low supersaturation, this suggests strong deviations near the spinodal line. PMID:25273436

Philippe, T; Blavette, D; Voorhees, P W

2014-09-28

216

Responses from electric stimulation of cochlear nucleus  

E-print Network

Cochlear nucleus (CN), the exclusive destination of the auditory nerve, is the gateway for all central processing of auditory information. The CN comprises three major subdivisions: anteroventral, posteroventral and dorsal ...

Suzuki, Ryuji, Ph. D. Massachusetts Institute of Technology

2010-01-01

217

Oxygen-ozone therapy for herniated lumbar disc in patients with subacute partial motor weakness due to nerve root compression.  

PubMed

Intradiscal oxygen-ozone (O2-O3) chemonucleolysis is a well-known effective treatment for pain caused by protruding disc disease and nerve root compression due to bulging or herniated disc. The most widely used therapeutic combination is intradiscal injection of an O2-O3 mixture (chemonucleolysis), followed by periradicular injection of O2-O3, steroid and local anaesthetic to enhance the anti-inflammatory and analgesic effect. The treatment is designed to resolve pain and is administered to patients without motor weakness, whereas patients with acute paralysis caused by nerve root compression undergo surgery 24-48h after the onset of neurological deficit. This paper reports on the efficacy of O2-O3 chemonucleolysis associated with anti-inflammatory foraminal injection in 13 patients with low back pain and cruralgia, low back pain and sciatica and subacute partial motor weakness caused by nerve root compression unresponsive to medical treatment. All patients were managed in conjunction with our colleagues in the Neurosurgery Unit of Bellaria Hospital and the IRCCS Institute of Neurological Sciences, Bologna. The outcomes obtained are promising: 100% patients had a resolution of motor weakness, while 84.6% had complete pain relief. Our results demonstrate that O2-O3 therapy can be considered a valid treatment option for this category of patients. PMID:25363257

Dall'Olio, Massimo; Princiotta, Ciro; Cirillo, Luigi; Budai, Caterina; de Santis, Fabio; Bartolini, Stefano; Serchi, Elena; Leonardi, Marco

2014-10-31

218

Functional architecture in the cell nucleus.  

PubMed Central

The major functions of the cell nucleus, including transcription, pre-mRNA splicing and ribosome assembly, have been studied extensively by biochemical, genetic and molecular methods. An overwhelming amount of information about their molecular mechanisms is available. In stark contrast, very little is known about how these processes are integrated into the structural framework of the cell nucleus and how they are spatially and temporally co-ordinated within the three-dimensional confines of the nucleus. It is also largely unknown how nuclear architecture affects gene expression. In order to understand how genomes are organized, and how they function, the basic principles that govern nuclear architecture and function must be uncovered. Recent work combining molecular, biochemical and cell biological methods is beginning to shed light on how the nucleus functions and how genes are expressed in vivo. It has become clear that the nucleus contains distinct compartments and that many nuclear components are highly dynamic. Here we describe the major structural compartments of the cell nucleus and discuss their established and proposed functions. We summarize recent observations regarding the dynamic properties of chromatin, mRNA and nuclear proteins, and we consider the implications these findings have for the organization of nuclear processes and gene expression. Finally, we speculate that self-organization might play a substantial role in establishing and maintaining nuclear organization. PMID:11368755

Dundr, M; Misteli, T

2001-01-01

219

Medium effect in the high-density region probed by nucleus-nucleus elastic scattering  

NASA Astrophysics Data System (ADS)

We investigate the sensitivity of the medium effect in the high-density region on nucleus-nucleus elastic scattering in the framework of the double-folding (DF) model with the complex G-matrix interaction. The medium effect including the three-body-force (TBF) effect is investigated with two methods. In both methods, the medium effect is clearly seen on the potential and the elastic cross section. Finally, we make clear the crucial role of the TBF effect up to kF=1.6 fm-1 in nucleus-nucleus elastic scattering.

Furumoto, T.; Sakuragi, Y.; Yamamoto, Y.

2014-10-01

220

(Nucleus-nucleus collisions): Foreign trip report, June 5--11, 1988  

SciTech Connect

The traveler attended the Third International Conference on Nucleus- Nucleus Collisions in St. Malo, France. The conference was attended by 450 physicists and provided a good review of the status of heavy-ion research from low to ultrarelativistic energies. The traveler was the convenor of the ''Round Table Discussion'' held during the closing session of the conference. The traveler proposed that the Fourth International Conference on Nucleus-Nucleus Collisions be held in Gatlinburg, Tennessee, in 1991. The present and voting members of the International Advisory Committee and of the National Organizing Committee deadlocked 10-10 between the traveler's proposal and a Japanese proposal.

Plasil, F.

1988-06-30

221

Computer program for parameterization of nucleus-nucleus electromagnetic dissociation cross sections  

NASA Technical Reports Server (NTRS)

A computer subroutine parameterization of electromagnetic dissociation cross sections for nucleus-nucleus collisions is presented that is suitable for implementation in a heavy ion transport code. The only inputs required are the projectile kinetic energy and the projectile and target charge and mass numbers.

Norbury, John W.; Townsend, Lawrence W.; Badavi, Forooz F.

1988-01-01

222

mRNA stability in the nucleus*  

PubMed Central

Eukaryotic gene expression is controlled by different levels of biological events, such as transcription factors regulating the timing and strength of transcripts production, alteration of transcription rate by RNA processing, and mRNA stability during RNA processing and translation. RNAs, especially mRNAs, are relatively vulnerable molecules in living cells for ribonucleases (RNases). The maintenance of quality and quantity of transcripts is a key issue for many biological processes. Extensive studies draw the conclusion that the stability of RNAs is dedicated-regulated, occurring co- and post-transcriptionally, and translation-coupled as well, either in the nucleus or cytoplasm. Recently, RNA stability in the nucleus has aroused much research interest, especially the stability of newly-made transcripts. In this article, we summarize recent progresses on mRNA stability in the nucleus, especially focusing on quality control of newly-made RNA by RNA polymerase II in eukaryotes. PMID:24793762

Liu, Han; Luo, Min; Wen, Ji-kai

2014-01-01

223

Interpretive monitoring in the caudate nucleus  

PubMed Central

In a dynamic environment an organism has to constantly adjust ongoing behavior to adapt to a given context. This process requires continuous monitoring of ongoing behavior to provide its meaningful interpretation. The caudate nucleus is known to have a role in behavioral monitoring, but the nature of these signals during dynamic behavior is still unclear. We recorded neuronal activity in the caudate nucleus in monkeys during categorization behavior that changed rapidly across contexts. We found that neuronal activity maintained representation of the identity and context of a recently categorized stimulus, as well as interpreted the behavioral meaningfulness of the maintained trace. The accuracy of this cognitive monitoring signal was highest for behavior for which subjects were prone to make errors. Thus, the caudate nucleus provides interpretive monitoring of ongoing behavior, which is necessary for contextually specific decisions to adapt to rapidly changing conditions. DOI: http://dx.doi.org/10.7554/eLife.03727.001

Yanike, Marianna; Ferrera, Vincent P

2014-01-01

224

Left hepatic lobe herniation through an incisional anterior abdominal wall hernia and right adrenal myelolipoma: a case report and review of the literature  

PubMed Central

Introduction Herniation of the liver through an anterior abdominal wall hernia defect is rare. To the best of our knowledge, only three cases have been described in the literature. Case presentation A 70-year-old Mexican woman presented with a one-week history of right upper quadrant abdominal pain, nausea, vomiting, and jaundice to our Department of General Surgery. Her medical history included an open cholecystectomy from 20 years earlier and excessive weight. She presented with jaundice, abdominal distension with a midline surgical scar, right upper quadrant tenderness, and a large midline abdominal wall defect with dullness upon percussion and protrusion of a large, tender, and firm mass. The results of laboratory tests were suggestive of cholestasis. Ultrasound revealed choledocholithiasis. A computed tomography scan showed a protrusion of the left hepatic lobe through the anterior abdominal wall defect and a well-defined, soft tissue density lesion in the right adrenal topography. An endoscopic common bile duct stone extraction was unsuccessful. During surgery, the right adrenal tumor was resected first. The hernia was approached through a median supraumbilical incision; the totality of the left lobe was protruding through the abdominal wall defect, and once the lobe was reduced to its normal position, a common bile duct surgical exploration with multiple stone extraction was performed. Finally, the abdominal wall was reconstructed. Histopathology revealed an adrenal myelolipoma. Six months after the operation, our patient remains in good health. Conclusions The case of liver herniation through an incisional anterior abdominal wall hernia in this report represents, to the best of our knowledge, the fourth such case reported in the literature. The rarity of this medical entity makes it almost impossible to specifically describe predisposing risk factors for liver herniation. Obesity, the right adrenal myelolipoma mass effect, and the previous abdominal surgery are likely to have contributed to incisional hernia formation. PMID:22234036

2012-01-01

225

Pion-nucleon scattering and pion production in nucleon-nucleon and nucleus-nucleus collisions  

SciTech Connect

Lecture notes are presented on the following: (1) basic aspects of ..pi..N interactions (properties of pions and nucleons, SU(3) and SU(6) classification phenomenology of ..pi..N scattering ((3.3) resonance; phase shift analysis, and bag model approach to ..pi..N); (2) pion production and absorption in the two nucleon system (NN ..-->.. NN..pi.. (isobar model) and ..pi..d reversible NN (existence of dibaryon resonances)); (3) pion absorption in complex nuclei (multiparticle aspects and cascade calculations); and (4) pion production with nuclear targets including (a) nucleon-nucleus, (b) nucleus-nucleus (Fermi-averaged 2-body vs thermodynamic models), and (c) ..pi pi.. interoferometry.

Dover, C.B.

1982-01-01

226

Compound nucleus studies withy reverse kinematics  

SciTech Connect

Reverse kinematics reactions are used to demonstrate the compound nucleus origin of intermediate mass particles at low energies and the extension of the same mechanism at higher energies. No evidence has appeared in our energy range for liquid-vapor equilibrium or cold fragmentation mechanisms. 11 refs., 12 figs.

Moretto, L.G.

1985-06-01

227

The nucleus of a multiprogramming system  

Microsoft Academic Search

This paper describes the philosophy and structure of a multi-programming system that can be extended with a hierarchy of operating systems to suit diverse requirements of program scheduling and resource allocation. The system nucleus simulates an environment in which program execution and input\\/output are handled uniformly as parallel, cooperating processes. A fundamental set of primitives allows the dynamic creation and

Per Brinch Hansen

1970-01-01

228

The Role of the Nucleus in Oxidation  

Microsoft Academic Search

Injury produces in the leaf-cells of the Indian Pipe (Monotropa uniflora) a darkening which is due to oxidation. The oxidation is much more rapid in the nucleus than in the cytoplasm and the facts indicate that this is also the case with the oxidation of the uninjured cell

W. J. V. Osterhout

1917-01-01

229

THE ROLE OF THE NUCLEUS IN OXIDATION.  

PubMed

Injury produces in the leaf-cells of the Indian Pipe (Monotropa uniflora) a darkening which is due to oxidation. The oxidation is much more rapid in the nucleus than in the cytoplasm and the facts indicate that this is also the case with the oxidation of the uninjured cell. PMID:17758977

Osterhout, W J

1917-10-12

230

Recent progress in eta-nucleus physics  

E-print Network

This is the summary of the 'International Workshop on eta--Nucleus Physics' held in Juelich, May 8--12, 2006. Each talk is represented by an extended abstract. At the same time the document provides a progress report of the corresponding working group.

Baru, V; Fix, A; Garcilazo, H; Gasparyan, A; Haidenbauer, J; Hanhart, C; Höistad, Bo; Kirillov, D; Krusche, B; Kudryavtsev, A; Kvinikhidze, S; Mersmann, T; Mosel, U; Moskal, P; Niskanen, J; Nogga, A; Oset, E; Peña, T; Shklyar, V; Sibirtsev, A A; Starostin, A; Svarc, A; Tiator, L; Wilkin, C; Wolke, M; Zlomanczuk, Yu; Baru, Vadim; Doering, Michael; Fix, Alexander; Garcilazo, Humberto; Gasparyan, Ashot; Haidenbauer, Johann; Hanhart, Christoph; Hoistad, Bo; Kirillov, Daniil; Krusche, Bernd; Kudryavtsev, Alexander; Kvinikhidze, Sasha; Mersmann, Timo; Mosel, Ulrich; Moskal, Pawel; Niskanen, Jouni; Nogga, Andreas; Oset, Eulogio; Pena, Teresa; Shklyar, Vitaliy; Sibirtsev, Alexander; Starostin, Aleksandr; Svarc, Alfred; Tiator, Lothar; Wilkin, Colin; Wolke, Magnus; Zlomanczuk, Jozef

2006-01-01

231

Recent progress in eta-nucleus physics  

E-print Network

This is the summary of the 'International Workshop on eta--Nucleus Physics' held in Juelich, May 8--12, 2006. Each talk is represented by an extended abstract. At the same time the document provides a progress report of the corresponding working group.

Vadim Baru; Michael Doering; Alexander Fix; Humberto Garcilazo; Ashot Gasparyan; Johann Haidenbauer; Christoph Hanhart; Bo Hoistad; Daniil Kirillov; Bernd Krusche; Alexander Kudryavtsev; Sasha Kvinikhidze; Timo Mersmann; Ulrich Mosel; Pawel Moskal; Jouni Niskanen; Andreas Nogga; Eulogio Oset; Teresa Pena; Vitaliy Shklyar; Alexander Sibirtsev; Aleksandr Starostin; Alfred Svarc; Lothar Tiator; Colin Wilkin; Magnus Wolke; Jozef Zlomanczuk

2006-10-04

232

Analysis of the Volumes of the Posterior Cranial Fossa, Cerebellum, and Herniated Tonsils Using the Stereological Methods in Patients with Chiari Type I Malformation  

PubMed Central

Objective. The aim of this study was to determine the posterior cranial fossa volume, cerebellar volume, and herniated tonsillar volume in patients with chiari type I malformation and control subjects using stereological methods. Material and Methods. These volumes were estimated retrospectively using the Cavalieri principle as a point-counting technique. We used magnetic resonance images taken from 25 control subjects and 30 patients with chiari type I malformation. Results. The posterior cranial fossa volume in patients with chiari type I malformation was significantly smaller than the volume in the control subjects (P < 0.05). In the chiari type I malformation group, the cerebellar volume was smaller than the control group, but this difference was not statistically significant (P > 0.05). In the chiari type I malformation group, the ratio of cerebellar volume to posterior cranial fossa volume was higher than in the control group. We also found a positive correlation between the posterior cranial fossa volume and cerebellar volume for each of the groups (r = 0.865, P < 0.001). The mean (±SD) herniated tonsillar volume and length were 0.89 ± 0.50?cm3 and 9.63 ± 3.37?mm in the chiari type I malformation group, respectively. Conclusion. This study has shown that posterior cranial fossa and cerebellum volumes can be measured by stereological methods, and the ratio of these measurements can contribute to the evaluation of chiari type I malformation cases. PMID:22629166

Vurdem, Umit Erkan; Acer, Niyazi; Ertekin, Tolga; Savranlar, Ahmet; Inci, Mehmet Fatih

2012-01-01

233

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

PubMed Central

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

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

2012-01-01

234

Herniation of Duodenum into the Right Ventral Hepatic Peritoneal Cavity with Groove Formation at the Ventral Hepatic Surface in a 2-Week-Old Chicken  

PubMed Central

ABSTRACT Internal hernia in avian species is very rare. A necropsy of a 2-week-old SPF White Leghorn chicken revealed that a loop of the duodenum and part of the pancreas (4 × 2 × 1 cm) was protruding through the abnormal foramen (2.5 cm in diameter) in the right posthepatic septum into the right ventral hepatic peritoneal cavity. The herniated loop was located underneath the ventral hepatic surface, leaving a groove on the right hepatic lobe (2 × 1.5 × 0.4 cm). The part of the pancreas involved in the hernia was grossly enlarged. Microscopically, a zone of pressure atrophy of hepatic tissue was characterized by crowdedness of hepatocytes with pyknotic nuclei and faint eosinophilic cytoplasm and indistinct narrow sinusoids. The pancreas revealed hypertrophy of the acinar cells with an increase in the secretory granules and basophilic cytoplasm. This is the first report of duodenum herniation into the right ventral hepatic peritoneal cavity resulting in groove formation on the ventral hepatic surface in a 2-week-old chicken. PMID:23759688

HARIDY, Mohie; SASAKI, Jun; GORYO, Masanobu

2013-01-01

235

Fusion cross sections for reactions involving medium & heavy nucleus-nucleus systems  

E-print Network

Existing data on near-barrier fusion excitation functions of medium and heavy nucleus-nucleus systems have been analyzed using a simple diffused barrier formula derived assuming the Gaussian shape of the barrier height distributions. Fusion cross section is obtained by folding the Gaussian barrier distribution with the classical expression for the fusion cross section for a fixed barrier. The energy dependence of the fusion cross section, thus obtained, provides good description to the existing data on near-barrier fusion and capture excitation functions for medium and heavy nucleus-nucleus systems. The fusion or capture cross section predictions are especially important for planning experiments for synthesizing new super-heavy elements.

Debasis Atta; D. N. Basu

2014-02-20

236

Microdiscectomy for the treatment of lumbar disc herniation: an evaluation of reoperations and long-term outcomes.  

PubMed

Design?Retrospective case series. Objective?The objective of this study was to assess the reoperation rate after microdiscectomy for the treatment of lumbar disc herniation (LDH) in patients with???5-year follow-up and identify demographic, perioperative, and outcome-related differences between patients with and without a reoperation. Methods?The medical records, operative reports, and office notes of patients who had undergone microdiscectomy at a single institution between March 1994 and December 2007 were reviewed and long-term follow-up was assessed via a telephone questionnaire. Results?Forty patients (M:24, F:16) with an average age at surgery of 39.9?±?12.5 years (range: 18-80) underwent microdiscectomy at the levels L5-S1 (n?=?28, 70%), L4-L5 (n?=?9, 22.5%), L3-L4 (n?=?2, 5.0%), and L1-L2 (n?=?1, 2.5%). After an average of 40.4?±?40.1 months (range: 1-128), 25% of patients (10/40) required further spine surgery related to the initial microdiscectomy. At an average postoperative follow-up of 11.1?±?4.0 years (range: 5-19), additional symptoms apart from back and leg pain were reported more frequently by patients who underwent a reoperation (p?=?0.005). Patient satisfaction was significantly higher in patients who did not undergo a reoperation (p?=?0.041). For the Oswestry disability index, pain intensity (p?=?0.036), and pain-related sleep disturbances (p?=?0.006) were reported to be more severe in the reoperation group. Conclusions?Microdiscectomy for the treatment of LDH results in a favorable long-term outcome in the majority of cases. The reoperation rate was higher in our series than reported in previous investigations with shorter follow-up. Although there were no statistically significant pre-/perioperative differences between patients with and without reoperation, our findings suggest a difference in self-reported long-term outcome measures. PMID:25278881

Aichmair, Alexander; Du, Jerry Y; Shue, Jennifer; Evangelisti, Gisberto; Sama, Andrew A; Hughes, Alexander P; Lebl, Darren R; Burket, Jayme C; Cammisa, Frank P; Girardi, Federico P

2014-10-01

237

Indirect projections from the suprachiasmatic nucleus to the median preoptic nucleus in rat.  

PubMed

We recently showed, using dual tract-tracing, that the suprachiasmatic nucleus (SCN), the site of the principal circadian clock in mammals, may have indirect projections to the sleep-promoting ventrolateral preoptic nucleus (VLPO) via relays in the medial preoptic area (MPA), dorsomedial hypothalamic nucleus (DMH), and, to a lesser extent, the subparaventricular zone (SPVZ). Here, we found that the injection of the rostral MPA, the periventricular nucleus/medial SPVZ, and the caudal DMH with a mixture of anterograde and retrograde tracers resulted in dense anterograde labeling in the median preoptic nucleus (MnPO), another key sleep-promoting nucleus in the preoptic region. The retrograde labeling in the SCN was evident as previously reported. The injections in either the MPA or the DMH produced similar densities of varicose fibers between the MnPO and the VLPO, while the injections in the SPVZ yielded a greater density of varicose fibers in the MnPO than in the VLPO. These results suggest that the MPA and DMH are potential relay nuclei to mediate SCN output to the MnPO, as well as to the VLPO, for the circadian control of sleep-wake states. PMID:14499951

Deurveilher, Samuel; Semba, Kazue

2003-10-10

238

Possible Mechanisms of Low Back Pain due to Whole-Body Vibration  

NASA Astrophysics Data System (ADS)

The investigators describe their multifaceted approach to the study of the relationship between whole-body vibration and low back pain.In vitroexperiments, using percutaneous pin-mounted accelerometers have shown that the natural frequency is at 4·5 Hz. The frequency response was affected by posture, seating, and seat-back inclination. The response appears to be largely determined by the rocking of the pelvis. Electromyographic studies have shown that muscle fatigue occurs under whole body vibration. After whole body vibration exposure the muscle response to a sudden load has greater latency. Vehicle driving may be a reason for low back pain or herniated nucleus pulposus. Prolonged seating exposure, coupled with the whole body vibration should be reduced for those recovering from these problems. Vibration attenuating seats, and correct ergonomic layout of the cabs may reduce the risks of recurrence.

Pope, M. H.; Wilder, D. G.; Magnusson, M.

1998-08-01

239

Reabilitação precoce de atletas utilizando hidroterapia após o tratamento cirúrgico de hérnia discal lombar: relato preliminar de 3 casos Early rehabilitation of athletes using hydrotherapy after surgical treatment of lumbar disc herniation: preliminary report of three cases  

Microsoft Academic Search

SUMMARY Three male athletes submitted to surgical treatment of lumbar disc herniation were assessed aiming to evaluate the results of a rehabilitation protocol based on aquatic therapy. This method allowed early rehabilitation of the athletes, within a week after surgery. The athletes were evaluated in 5 occasions: pre-operatively and in the 4 following months. Complete improvement of pain was observed

MARCELO W AJCHEMBERG; LEONARDO P IRES; REYNALDO C. RODRIGUES; KARINA S. MANO; MORGANA DE SÁ SOTTOMAIOR; MOISÉS COHEN; RENE J. ABDALLA; EDUARDO B. PUERTAS

2002-01-01

240

Finite nucleus effects on relativistic energy corrections  

NASA Technical Reports Server (NTRS)

The effect of using a finite nucleus model in quantum-chemical calculations is examined. Relativistic corrections from the first order Foldy-Wouthuysen terms are affected indirectly by the change in wavefunction, but also directly as a result of revised expressions for the Darwin and spin-orbit terms due to the change in nuclear potential. A calculation for the Rn atom indicates that the mass-velocity and Darwin corrections are much more sensitive to the finite nucleus than the non-relativistic total energy, but that the total contribution for these two terms is quite stable provided the revised form of the Darwin term is used. The spin-orbit interaction is not greatly affected by the choice of nuclear model.

Dyall, Kenneth G.; Faegri, Knut, Jr.

1993-01-01

241

Nucleus-nucleus potential with shell-correction contribution and deep sub-barrier fusion of heavy nuclei  

NASA Astrophysics Data System (ADS)

It is suggested that the full nucleus-nucleus potential consists of the macroscopic and shell-correction parts. The deep sub-barrier fusion hindrance takes place in a nucleus-nucleus system with a strong negative shell-correction contribution to the full heavy-ion potential, while a strong positive shell-correction contribution to the full potential leads to weak enhancement of the deep sub-barrier fusion cross section.

Denisov, V. Yu.

2014-04-01

242

Spectrophotometry of comets. [cometary nucleus model  

NASA Technical Reports Server (NTRS)

Photoelectric spectrophotometric- and image tube equipped spectrographic-studies on comets are used to formulate a new model for the cometary nucleus that is physically similar to the icy-conglomerate. Absolute flux distributions of the principal spectral features for five comets of different compositions and heliocentric distances were evaluated. Comparison of visible and infrared brightnesses was used to calculate the optical albedos of observed particles.

Odell, C. R.

1974-01-01

243

Possible Existence of -Nucleus Bound States  

NASA Astrophysics Data System (ADS)

Charmonium () bound states in few-nucleon systems, 2H, 4He and 8Be, are studied via Gaussian Expansion Method (GEM). We adopt a Gaussian potential as an effective -nucleon ( N) interaction. The relation between two-body - N scattering length and the binding energies B of -nucleus bound states are given. Recent lattice QCD data of corresponds to MeV for He and 2 MeV for Be in our results.

Yokota, Akira; Hiyama, Emiko; Oka, Makoto

2014-08-01

244

Dielectron Production in Proton-Nucleus Reactions  

E-print Network

M University, College Station, Texas 77843 (Received 15 August 1989) Dielectron production in proton-nucleus reactions is studied in the cascade model. In addition to production from the proton-neutron bremsstrahlung and the decay of delta, we have also... impor- tance of the various processes which contribute to its pro- duction. Theoretical work up to now has been concentrat- ed on dielectron production from the proton-neutron bremsstrahlung, 6' from the decay of delta, ' and from the pion...

Xiong, L.; Wu, J. Q.; Wu, Z. G.; Ko, Che Ming; Shi, J. H.

1990-01-01

245

SIGNAL TRANSDUCTION: Inositol Phosphates in the Nucleus  

NSDL National Science Digital Library

Access to the article is free, however registration and sign-in are required. The inositol signaling pathways in the cytoplasm are well characterized. In a Perspective, Chi and Crabtree now explain how similar inositol pathways operate in the nucleus to switch gene expression on and off. One of the key players is the kinase Ipk2p, which might stabilize components of a transcription complex (Odom et al.).

Tian H. Chi (Stanford University Medical School;Department of Developmental Biology and Department of Pathology)

2000-03-17

246

Physical Properties of Cometary Nucleus Candidates  

NASA Technical Reports Server (NTRS)

In this proposal we aim to study the physical properties of the Centaurs and the dead comets, these being the precursors to, and the remnants from, the active cometary nuclei. The nuclei themselves are very difficult to study, because of the contaminating effects of near-nucleus coma. Systematic investigation of the nuclei both before they enter the zone of strong sublimation and after they have depleted their near-surface volatiles should neatly bracket the properties of these objects, revealing evolutionary effects.

Jewitt, David; Hillman, John (Technical Monitor)

2003-01-01

247

Protein Quality Control in the Nucleus  

PubMed Central

In their natural environment, cells are regularly exposed to various stress conditions that may lead to protein misfolding, but also in the absence of stress, misfolded proteins occur as the result of mutations or failures during protein synthesis. Since such partially denatured proteins are prone to aggregate, cells have evolved several elaborate quality control systems to deal with these potentially toxic proteins. First, various molecular chaperones will seize the misfolded protein and either attempt to refold the protein or target it for degradation via the ubiquitin-proteasome system. The degradation of misfolded proteins is clearly compartmentalized, so unique degradation pathways exist for misfolded proteins depending on whether their subcellular localization is ER/secretory, mitochondrial, cytosolic or nuclear. Recent studies, mainly in yeast, have shown that the nucleus appears to be particularly active in protein quality control. Thus, specific ubiquitin-protein ligases located in the nucleus, target not only misfolded nuclear proteins, but also various misfolded cytosolic proteins which are transported to the nucleus prior to their degradation. In comparison, much less is known about these mechanisms in mammalian cells. Here we highlight recent advances in our understanding of nuclear protein quality control, in particular regarding substrate recognition and proteasomal degradation. PMID:25010148

Nielsen, Sofie V.; Poulsen, Esben G.; Rebula, Caio A.; Hartmann-Petersen, Rasmus

2014-01-01

248

Mass Segregation in the Galactic Nucleus  

NASA Astrophysics Data System (ADS)

Using a set of dynamically evolving Fokker-Planck simulations, we have examined the mass segregation of stars within the Galactic Nucleus. The models initially include a central seed black hole which is fed mass from the surrounding stellar population due to tidal disruptions of stars, stellar collisions, and stellar evolution. All mass loss due to stellar collisions and tidal disruptions is fed to the central black hole due to the proximity of these events to the black hole. A preset fraction of mass loss due to stellar evolution is allowed to be fed to the central black hole and the remainder is assumed to be ejected from the nucleus. This preset fraction is a model parameter that can be varied from 0 to 1. The initial stellar population has initial masses from 0.1 to 100 solar masses. In addition to using the Kroupa mass function models using pure power laws are also examined. As the stellar population evolves possible stellar end states are black holes, neutron stars, and white dwarfs. In the best fitting model of the Galactic Nucleus the region closest to the central black hole is dominated by stellar remnants due to the depletion of normal stars due to stellar collisions. At larger radii the dominate depletion mechanism is tidal disruptions. In this region the most massive stellar mass groups have a power-law density slopes of -7/4. Less massive stellar species have progressively smaller slopes that approach -3/2.

Murphy, Brian W.; Phifer, K. A.; Cohn, H. N.; Lugger, P. M.

2009-01-01

249

The Dusty Starburst Nucleus of M33  

E-print Network

We have thoroughly characterized the ultraviolet to near-infrared (0.15 - 2.2 micron) spectral energy distribution (SED) of the central parsec of the M33 nucleus through new infrared photometry and optical/near-infrared spectroscopy, combined with ultraviolet/optical observations from the literature and the HST archive. The SED shows evidence for a significant level of attenuation, which we model through a Monte Carlo radiative transfer code as a shell of clumpy Milky Way-type dust (tau_V ~ 2 +/- 1). The discovery of Milky Way-type dust (with a strong 2175 A bump) internal to the M33 nucleus is different from previous work which has found SMC-like dust (no bump) near starburst regions. The amount by which dust can be processed may be related to the mass and age of the starburst as well as the extent to which the dust can shield itself. Our starburst models include the effects of this dust and can fit the SED if the nucleus was the site of a moderate (~10^8 L_sun at 10 Myrs) episode of coeval star formation about 70 Myrs ago. This result is quite different from previous studies which resorted to multiple stellar populations (between 2 and 7) attenuated by either no or very little internal dust. The M33 nuclear starburst is remarkably similar to an older version (70 Myr versus 10 Myr) of the ultra-compact starburst in the center of the Milky Way.

K. D. Gordon; M. M. Hanson; G. C. Clayton; G. H. Rieke; K. A. Misselt

1999-02-02

250

Comet nucleus and asteroid sample return missions  

NASA Astrophysics Data System (ADS)

Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus.

1992-06-01

251

Comet nucleus and asteroid sample return missions  

NASA Technical Reports Server (NTRS)

Three Advanced Design Projects have been completed this academic year at Penn State. At the beginning of the fall semester the students were organized into eight groups and given their choice of either a comet nucleus or an asteroid sample return mission. Once a mission had been chosen, the students developed conceptual designs. These were evaluated at the end of the fall semester and combined into three separate mission plans, including a comet nucleus same return (CNSR), a single asteroid sample return (SASR), and a multiple asteroid sample return (MASR). To facilitate the work required for each mission, the class was reorganized in the spring semester by combining groups to form three mission teams. An integration team consisting of two members from each group was formed for each mission so that communication and information exchange would be easier among the groups. The types of projects designed by the students evolved from numerous discussions with Penn State faculty and mission planners at the Johnson Space Center Human/Robotic Spacecraft Office. Robotic sample return missions are widely considered valuable precursors to manned missions in that they can provide details about a site's environment and scientific value. For example, a sample return from an asteroid might reveal valuable resources that, once mined, could be utilized for propulsion. These missions are also more adaptable when considering the risk to humans visiting unknown and potentially dangerous locations, such as a comet nucleus.

1992-01-01

252

The Effects of Stretching with Lumbar Traction on VAS and Oswestry Scales of Patients with Lumbar 4-5 Herniated Intervertebral Disc  

PubMed Central

[Purpose] This study investigated the effect of stretching with lumbar traction on VAS and Oswestry scale scores of lumbar 4–5 herniated intervertebral disc (HIVD) patients. [Subjects] We recruited 20 lumbar 4–5 HIVD patients. [Methods] We performed stretching with lumbar traction for lumbar 4–5 HIVD patients during 4 weeks. The VAS and Oswestry scales were measured before and 4 weeks after the intervention. [Results] The results showed a significant decrease in VAS scale scores for stretching with lumbar traction in lumbar 4–5 HIVD patients, from 18±1.29 to 2.1±1.35. The Oswestry scale scores also decreased significantly, from 20.35±2.01 to 3.5±2.84, after stretching with lumbar traction. [Conclusion] Thus, we suggest stretching with lumbar traction for lumbar 4–5 HIVD patients. PMID:25140094

Yang, Hae-sun; Yoo, Won-gyu

2014-01-01

253

Pion and Kaon Lab Frame Differential Cross Sections for Intermediate Energy Nucleus-Nucleus Collisions  

NASA Technical Reports Server (NTRS)

Space radiation transport codes require accurate models for hadron production in intermediate energy nucleus-nucleus collisions. Codes require cross sections to be written in terms of lab frame variables and it is important to be able to verify models against experimental data in the lab frame. Several models are compared to lab frame data. It is found that models based on algebraic parameterizations are unable to describe intermediate energy differential cross section data. However, simple thermal model parameterizations, when appropriately transformed from the center of momentum to the lab frame, are able to account for the data.

Norbury, John W.; Blattnig, Steve R.

2008-01-01

254

Analysis of nucleus-nucleus collisions at high energies and Random Matrix Theory  

E-print Network

We propose a novel statistical approach to the analysis of experimental data obtained in nucleus-nucleus collisions at high energies which borrows from methods developed within the context of Random Matrix Theory. It is applied to the detection of correlations in momentum distributions of emitted particles. We find good agreement between the results obtained in this way and a standard analysis based on the method of effective mass spectra and two-pair correlation function often used in high energy physics. The method introduced here is free from unwanted background contributions.

R. G. Nazmitdinov; E. I. Shahaliev; M. K. Suleymanov; S. Tomsovic

2008-04-07

255

Effects of a chiral three-nucleon force on nucleus-nucleus scattering  

E-print Network

We investigate the effects of chiral NNLO three-nucleon force (3NF) on nucleus-nucleus elastic scattering, using a standard prescription based on the Brueckner-Hartree-Fock method and the g-matrix folding model. The g-matrix calculated in nuclear matter from the chiral N3LO two-nucleon forces (2NF) is close to that from the Bonn-B 2NF. Because the Melbourne group have already developed a practical g-matrix interaction by localizing the nonlocal g-matrix calculated from the Bonn-B 2NF, we consider the effects of chiral 3NF, in this first attempt to study the 3NF effects, by modifying the local Melbourne g-matrix according to the difference between the g-matrices of the chiral 2NF and 2NF+3NF. For nucleus-nucleus elastic scattering, the 3NF corrections make the folding potential less attractive and more absorptive. The latter novel effect is due to the enhanced tensor correlations in triplet channels. These changes reduce the differential cross section at the middle and large angles, improving the agreement with the experimental data for 16O-16O scattering at 70 MeV/nucleon and 12C-12C scattering at 85 MeV/nucleon.

Kosho Minomo; Masakazu Toyokawa; Michio Kohno; Masanobu Yahiro

2014-04-22

256

Nucleus-nucleus cold fusion reactions analyzed with the l-dependent ``fusion by diffusion'' model  

Microsoft Academic Search

We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section sigmacap(l),

T. Cap; K. Siwek-Wilczynska; J. Wilczynski

2011-01-01

257

Nucleus-nucleus cold fusion reactions analyzed with the l-dependent 'fusion by diffusion' model  

Microsoft Academic Search

We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section {sub

T. Cap; K. Siwek-Wilczynska; J. Wilczynski

2011-01-01

258

On M31's Double Nucleus  

NASA Technical Reports Server (NTRS)

The recent HST discovery of a double nucleus in M31 brings into prominence the question how long, a second core can survive within the nuclear regions of a galaxy. Physical conditions in the nuclear regions of a typical galaxy help a second core survive, so it can orbit for a long time. possibly for thousands of orbits. Given the nearly uniform mass density in a core, tidal forces within a core radius are compressive in all directions and help the core survive the buffeting it takes as it orbits near the center of the galaxy. We use numerical experiments to illustrate these physical principles. Our method allows the full power of the experiments to be concentrated on the nuclear regions. Spatial resolution of about 0.2 pc comfortably resolves detail within the 1.4 parsec core radius of the second, but brighter core (P1) in M31. We use these physical principles to discuss M31's double nucleus, but they apply to other galaxies as well. and in other astronomical situations such as dumbbell galaxies. galaxies orbiting near the center of a galaxy cluster, and subclustering in galaxy clusters. The experiments also illustrate that galaxy encounters and merging are quite sensitive to external tidal forces, such as those produced by the gravitational potential in a group or cluster of galaxies.

Miller, R. H.; Smith, B. F.; Cuzzi, Jeffrey (Technical Monitor)

1995-01-01

259

Prestress mediates force propagation into the nucleus  

SciTech Connect

Several reports show that the nucleus is 10 times stiffer than the cytoplasm. Hence, it is not clear if intra-nuclear structures can be directly deformed by a load of physiologic magnitudes. If a physiologic load could not directly deform intra-nuclear structures, then signaling inside the nucleus would occur only via the mechanisms of diffusion or translocation. Using a synchronous detection approach, we quantified displacements of nucleolar structures in cultured airway smooth muscle cells in response to a localized physiologic load ({approx}0.4 {mu}m surface deformation) via integrin receptors. The nucleolus exhibited significant displacements. Nucleolar structures also exhibited significant deformation, with the dominant strain being the bulk strain. Increasing the pre-existing tensile stress (prestress) in the cytoskeleton significantly increased the stress propagation efficiency to the nucleolus (defined as nucleolus displacement per surface deformation) whereas decreasing the prestress significantly lowered the stress propagation efficiency to the nucleolus. Abolishing the stress fibers/actin bundles by plating the cells on poly-L-lysine-coated dishes dramatically inhibited stress propagation to the nucleolus. These results demonstrate that the prestress in the cytoskeleton is crucial in mediating stress propagation to the nucleolus, with implications for direct mechanical regulation of nuclear activities and functions.

Hu Shaohua [Physiology Program, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States); Chen Jianxin [Physiology Program, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States); Butler, James P. [Physiology Program, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States); Wang Ning [Physiology Program, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States)]. E-mail: nwang@hsph.harvard.edu

2005-04-08

260

Comet Borrelly Nucleus Found to the Side  

NASA Technical Reports Server (NTRS)

Deep Space 1 flew by comet Borrelly on September 22, 2001 and took these measurements with its plasma instruments between 90,000 kilometers (56,000 miles) and 2,000 kilometers (1,200 miles) away. These data show that the flow of ions around the comet's rocky, icy nucleus (the center of the deep V-shaped feature) is not centered on the comet's nucleus as scientists expected before the Borrelly flyby. Ions in the turbulent flow are heated to about 1 million Kelvin (2 million degrees Fahrenheit) causing the bands of ions to appear broad and jagged compared to the solar wind.

Deep Space 1 completed its primary mission testing ion propulsion and 11 other advanced, high-risk technologies in September 1999. NASA extended the mission, taking advantage of the ion propulsion and other systems to undertake this chancy but exciting, and ultimately successful, encounter with the comet. More information can be found on the Deep Space 1 home page at http://nmp.jpl.nasa.gov/ds1/ .

Deep Space 1 was launched in October 1998 as part of NASA's New Millennium Program, which is managed by JPL for NASA's Office of Space Science, Washington, D.C. The California Institute of Technology manages JPL for NASA.

2001-01-01

261

Comet nucleus and asteroid sample return missions  

NASA Technical Reports Server (NTRS)

During the 1991-92 academic year, the Pennsylvania State University has developed three sample return missions: one to the nucleus of comet Wild 2, one to the asteroid Eros, and one to three asteroids located in the Main Belt. The primary objective of the comet nucleus sample return mission is to rendezvous with a short period comet and acquire a 10 kg sample for return to Earth. Upon rendezvous with the comet, a tethered coring and sampler drill will contact the surface and extract a two-meter core sample from the target site. Before the spacecraft returns to Earth, a monitoring penetrator containing scientific instruments will be deployed for gathering long-term data about the comet. A single asteroid sample return mission to the asteroid 433 Eros (chosen for proximity and launch opportunities) will extract a sample from the asteroid surface for return to Earth. To limit overall mission cost, most of the mission design uses current technologies, except the sampler drill design. The multiple asteroid sample return mission could best be characterized through its use of future technology including an optical communications system, a nuclear power reactor, and a low-thrust propulsion system. A low-thrust trajectory optimization code (QuickTop 2) obtained from the NASA LeRC helped in planning the size of major subsystem components, as well as the trajectory between targets.

Melton, Robert G.; Thompson, Roger C.; Starchville, Thomas F., Jr.; Adams, C.; Aldo, A.; Dobson, K.; Flotta, C.; Gagliardino, J.; Lear, M.; Mcmillan, C.

1992-01-01

262

Odyssey Comet Nucleus Orbiter: The Next Step in Cometary Exploration  

NASA Technical Reports Server (NTRS)

Cometary nuclei are the most primitive bodies in the solar system, containing a cosmo-chemical record of the primordial solar nebula. Flyby missions to comets, such as those that encountered Comet Halley in 1986, provide a glimpse at this record. However, to study a cometary nucleus in detail requires a rendezvous mission, i.e., a nucleus orbiter. Only an orbiter provides the ability to map the entire nucleus surface at high resolution, to study the complex chemistry in the cometary coma and its variation with time, and to determine the mass and bulk density of the nucleus, key parameters in understanding how small bodies first formed in the solar nebula. A nucleus orbiter also provides the opportunity to sense the nucleus surface in preparation for more ambitious landing and sample return missions in the future. Additional information is contained in the original extended abstract.

Weissman, P. R.; Nilsen, E. N.; Smythe, W. D.; Marriott, J.; Reinert, R.

2001-01-01

263

A search for ? meson nucleus bound state using antiproton annihilation on nucleus  

NASA Astrophysics Data System (ADS)

The mass shift of the vector mesons in nuclei is known to be a powerful tool for investigating the mechanism of generating hadron mass from the QCD vacuum. The mechanism is known to be the spontaneous breaking of chiral symmetry. In 2007, KEK-PS E325 experiment reported about 3.4 % mass reduction of the ? meson in medium-heavy nuclei (Cu). This result is possibly one of the indications of the partial restoration of chiral symmetry in nuclei, however, unfortunately it is hard to make strong conclusions from the data. One of the ways to conclude the strength of the ? meson mass shift in nuclei will be by trying to produce only slowly moving ? mesons where the maximum nuclear matter effect can be probed. The observed mass reduction of the ? meson in the nucleus can be translated as the existence of an attractive force between ? meson and nucleus. Thus, one of the extreme conditions that can be achieved in the laboratory is indeed the formation of a ?-nucleus bound state, where the ? meson is "trapped" in the nucleus. The purpose of the experiment is to search for a ?-nucleus bound state and measure the binding energy of the system. We will demonstrate that a completely background-free missing-mass spectrum can be obtained efficiently by (bar{p}, ?) spectroscopy together with K + ? tagging, using the primary reaction channel bar{p} p rightarrow ? ?. This paper gives an overview of the physics motivation and the detector concept, and explains the direction of the initial research and development effort.

Ohnishi, H.; Bühler, P.; Cargnelli, M.; Curceanu, C.; Guaraldo, C.; Hartmann, O.; Hicks, K.; Iwasaki, M.; Ishiwatari, T.; Kienle, P.; Marton, J.; Muto, R.; Naruki, M.; Niiyama, M.; Noumi, H.; Okada, S.; Vidal, A. Romero; Sakaguchi, A.; Sakuma, F.; Sawada, S.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Tsukada, K.; Doce, O. Vazquez; Widmann, E.; Yokkaichi, S.; Zmeskal, J.

264

In vitro and in silico investigations of disc nucleus replacement  

PubMed Central

Currently, numerous hydrogels are under examination as potential nucleus replacements. The clinical success, however, depends on how well the mechanical function of the host structure is restored. This study aimed to evaluate the extent to and mechanisms by which surgery for nucleus replacements influence the mechanical behaviour of the disc. The effects of an annulus defect with and without nucleus replacement on disc height and nucleus pressure were measured using 24 ovine motion segments. The following cases were considered: intact; annulus incision repaired by suture and glue; annulus incision with removal and re-implantation of nucleus tissue repaired by suture and glue or plug. To identify the likely mechanisms observed in vitro, a finite-element model of a human disc (L4–L5) was employed. Both studies were subjected to physiological cycles of compression and recovery. A repaired annulus defect did not influence the disc behaviour in vitro, whereas additional nucleus removal and replacement substantially decreased disc stiffness and nucleus pressure. Model predictions demonstrated the substantial effects of reductions in replaced nucleus water content, bulk modulus and osmotic potential on disc height loss and pressure, similar to measurements. In these events, the compression load transfer in the disc markedly altered by substantially increasing the load on the annulus when compared with the nucleus. The success of hydrogels for nucleus replacements is not only dependent on the implant material itself but also on the restoration of the environment perturbed during surgery. The substantial effects on the disc response of disruptions owing to nucleus replacements can be simulated by reduced nucleus water content, elastic modulus and osmotic potential. PMID:22337630

Reitmaier, Sandra; Shirazi-Adl, Aboulfazl; Bashkuev, Maxim; Wilke, Hans-Joachim; Gloria, Antonio; Schmidt, Hendrik

2012-01-01

265

Recent results on (anti)nucleus and (anti)hyperon production in nucleus-nucleus collisions at CERN SPS energies  

E-print Network

The NA49 experiment has collected comprehensive data on particle production in nucleus-nucleus collisions over the whole SPS beam energies range, the critical energy domain where the expected phase transition to a deconfined phase is expected to occur. The latest results from Pb+Pb collisions between 20$A$ GeV and 158$A$ GeV on baryon stopping and light nuclei production as well as those for strange hyperons are presented. The measured data on $p$, $\\bar{p}$, $\\Lambda$, $\\bar{\\Lambda}$, $\\Xi^-$ and $\\bar{\\Xi}^+$ production were used to evaluate the rapidity distributions of net-baryons at SPS energies and to compare with the results from the AGS and the RHIC for central Pb+Pb (Au+Au) collisions. The dependence of the yield ratios and the inverse slope parameter of the $m_t$ spectra on the collision energy and centrality, and the mass number of the produced nuclei $^3He$, $t$, $d$ and $\\bar{d}$ are discussed within coalescence and statistical approaches. Analysis of the total multiplicity exhibits remarkable agreement between the measured yield for $^3He$ and those predicted by the statistical hadronization model. In addition, new results on $\\Lambda$ and $\\bar{\\Lambda}$ as well as $\\Xi^-$ production in minimum bias Pb+Pb reactions at 40$A$ GeV and 158$A$ GeV and central C+C, Si+Si and Pb+Pb collisions are presented. The system size dependence of the yields of these hyperons was analysed to determine the evolution of strangeness enhancement relative to elementary p+p collisions.

G. L. Melkumov; for the NA49 collaboration

2007-09-19

266

Analysis of Returned Comet Nucleus Samples  

NASA Technical Reports Server (NTRS)

This volume contains abstracts that have been accepted by the Program Committee for presentation at the Workshop on Analysis of Returned Comet Nucleus Samples, held in Milpitas, California, January 16-18, 1989. Conveners are Sherwood Chang (NASA Ames Research Center) and Larry Nyquist (NASA Johnson Space Center). Program Committee members are Thomas Ahrens (ex-officio; California Institute of Technology), Lou Allamandola (NASA Ames Research Center), David Blake (NASA Ames Research Center), Donald Brownlee (University of Washington, Seattle), Theodore E. Bunch (NASA Ames Research Center), Humberto Campins (Planetary Science Institute), Jeff Cuzzi (NASA Ames Research Center), Eberhard Griin (Max-Plank-Institut fiir Kemphysik), Martha Hanner (Jet Propulsion Laboratory), Alan Harris (Jet Propulsion Laboratory), John Kerrid-e (University of Califomia, Los Angeles), Yves Langevin (University of Paris), Gerhard Schwehm (ESTEC), and Paul Weissman (Jet Propulsion Laboratory). Logistics and administrative support for the workshop were provided by the Lunar and Planetary Institute Projects Office.

Chang, Sherwood (Compiler)

1997-01-01

267

Delta-nucleus dynamics: proceedings of symposium  

SciTech Connect

The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

1983-10-01

268

Recent Developments in the Study of Deconfinement in Nucleus-Nucleus Collisions  

E-print Network

Deconfinement refers to the creation of a state of quasi-free quarks and gluons in strongly interacting matter. Model predictions and experimental evidence for the onset of deconfinement in nucleus-nucleus collisions were discussed in our first review on this subject. These results motivated further experimental and theoretical studies. This review addresses two subjects. First, a summary of the past, present and future experimental programmes related to discovery and study of properties of the onset of deconfinement are %briefly presented. Second, recent progress is reviewed on analysis methods and preliminary experimental results for new strongly intensive fluctuation measures are discussed, which are relevant for current and future studies of the onset of deconfinement and searches for the critical point of strongly interacting matter

M. Gazdzicki; M. I. Gorenstein; P. Seyboth

2014-04-14

269

Fluctuation analysis of relativistic nucleus-nucleus collisions in emulsion chambers  

NASA Technical Reports Server (NTRS)

An analytical technique was developed for identifying enhanced fluctuations in the angular distributions of secondary particles produced from relativistic nucleus-nucleus collisions. The method is applied under the assumption that the masses of the produced particles are small compared to their linear momenta. The importance of particles rests in the fact that enhanced fluctuations in the rapidity distributions is considered to be an experimental signal for the creation of the quark-gluon-plasma (QGP), a state of nuclear matter predicted from the quantum chromodynamics theory (QCD). In the approach, Monte Carlo simulations are employed that make use of a portable random member generator that allow the calculations to be performed on a desk-top computer. The method is illustrated with data taken from high altitude emulsion exposures and is immediately applicable to similar data from accelerator-based emulsion exposures.

Mcguire, Stephen C.

1988-01-01

270

Forward-backward correlations in nucleus-nucleus collisions: Baseline contributions from geometrical fluctuations  

SciTech Connect

We discuss the effects of initial collision geometry and centrality bin definition on correlation and fluctuation observables in nucleus-nucleus collisions. We focus on the forward-backward correlation coefficient recently measured by the STAR Collaboration in Au+Au collisions at RHIC. Our study is carried out within two models: the Glauber Monte Carlo code with a 'toy' wounded-nucleon model and the hadron-string dynamics (HSD) transport approach. We show that strong correlations can arise from averaging over events in one centrality bin. We, furthermore, argue that a study of the dependence of correlations on the centrality bin definition as well as the bin size may distinguish between these trivial correlations and correlations arising from new physics.

Konchakovski, V. P. [Helmholtz Research School, University of Frankfurt, Frankfurt (Germany); Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine); Hauer, M. [Helmholtz Research School, University of Frankfurt, Frankfurt (Germany); Torrieri, G [Institut fuer Theoretische Physik, Goethe Universitaet, Frankfurt am Main (Germany); Gorenstein, M. I. [Bogolyubov Institute for Theoretical Physics, Kiev (Ukraine); Frankfurt Institute for Advanced Studies, Frankfurt (Germany); Bratkovskaya, E. L. [Frankfurt Institute for Advanced Studies, Frankfurt (Germany)

2009-03-15

271

Nucleus-Nucleus Collisions at Low Energies. The Effects from Non Vacuum Exchange  

E-print Network

Experimental data on total and differential elastic cross sections for $p+p(\\bar{p})$, $n+p(\\bar{p})$, $K^\\pm+p$, $K^\\pm+n$, $\\pi^\\pm+p$ starting from energy 3.5 GeV in CMS are used to determine parameters of vacuum contribution and parameters of basic non vacuum reggeons: $f$, $\\omega$, $\\rho$ and $A_2$. It is argued that non vacuum contributions to proton-proton and proton-neutron collisions correspond to spectrum in which baryon number is moved from the fragmentation region to central region in rapidity space. In this case it is possible that chemical potential is increased in central region of spectrum of nucleus-nucleus interaction at low energies. This effect might be important for facilities FAIR and NICA.

N. V. Radchenko; A. V. Dmitriev

2010-10-25

272

Production of cold fragments in nucleus-nucleus collisions in the Fermi-energy domain  

E-print Network

The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 - 29 observed in the reactions 86Kr+124,112Sn at 25 AMeV. The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of 132Sn where e.g. the reaction 132Sn+238U at 28 AMeV appears as a possible alternative to the use of fragmentation reactions at higher energies.

Veselsky, M

2007-01-01

273

Production of cold fragments in nucleus-nucleus collisions in the Fermi-energy domain  

E-print Network

The reaction mechanism of nucleus-nucleus collisions at projectile energies around the Fermi energy is investigated with emphasis on the production of fragmentation-like residues. The results of simulations are compared to experimental mass distributions of elements with Z = 21 - 29 observed in the reactions 86Kr+124,112Sn at 25 AMeV. The model of incomplete fusion is modified and a component of excitation energy of the cold fragment dependent on isospin asymmetry is introduced. The modifications in the model of incomplete fusion appear consistent with both overall model framework and available experimental data. A prediction is provided for the production of very neutron-rich nuclei using a secondary beam of 132Sn where e.g. the reaction 132Sn+238U at 28 AMeV appears as a possible alternative to the use of fragmentation reactions at higher energies.

M. Veselsky; G. A. Souliotis

2006-07-17

274

Cytotoxicity of nucleus-targeting fluorescent gold nanoclusters.  

PubMed

Gold nanoclusters (AuNCs) with ultra small sizes and unique fluorescence properties have shown promising potential for imaging the nuclei of living cells. However, little is known regarding the potential cytotoxicity of AuNCs after they enter the cell nucleus. The aim of this study is to investigate whether and how nucleus-targeting AuNCs affect the normal functioning of cells. Highly stable, water-soluble and bright fluorescent Au25NCs (the core of each nanocluster is composed of 25 gold atoms) were synthesized. Specific targeting of Au25NCs to the cell nucleus was achieved by conjugating the TAT peptide to the Au25NCs. Cell viability, cell morphology, cell apoptosis/necrosis, reactive oxygen species (ROS) level and mitochondrial membrane potential examinations were performed on different cell lines exposed to the nucleus-targeting Au25NCs. We found that the nucleus-targeting Au25NCs caused cell apoptosis in a dose-dependent manner. A possible mechanism for the cytotoxicity of the nucleus-targeting Au25NCs was proposed as follows: the nucleus-targeting Au25NCs induce the production of ROS, resulting in the oxidative degradation of mitochondrial components, in turn leading to apoptosis via a mitochondrial damage pathway. This work facilitates a better understanding of the toxicity of AuNCs, especially nucleus-targeting AuNCs. PMID:25250903

Zhao, Jing-Ya; Cui, Ran; Zhang, Zhi-Ling; Zhang, Mingxi; Xie, Zhi-Xiong; Pang, Dai-Wen

2014-11-01

275

The Confined Hydrogen Atom with a Moving Nucleus  

ERIC Educational Resources Information Center

We study the hydrogen atom confined to a spherical box with impenetrable walls but, unlike earlier pedagogical articles on the subject, we assume that the nucleus also moves. We obtain the ground-state energy approximately by means of first-order perturbation theory and show that it is greater than that for the case in which the nucleus is clamped…

Fernandez, Francisco M.

2010-01-01

276

Eccentric-Disk Models for the Nucleus of M31  

Microsoft Academic Search

We construct dynamical models of the ``double'' nucleus of M31 in which the nucleus consists of an eccentric disk of stars orbiting a central black hole. The principal approximation in these models is that the disk stars travel in a Keplerian potential; i.e., we neglect the mass of the disk relative to the black hole. We consider both ``aligned'' models,

Hiranya V. Peiris; Scott Tremaine

2003-01-01

277

ROSETTA mission: satellite orbits around a cometary nucleus  

Microsoft Academic Search

This paper discusses the problem of orbiting a comet nucleus from a perspective of orbital stability. The main forces perturbing the motion of the spacecraft around the comet: shape and rotation rate of the nucleus, comet outgassing, solar radiation pressure; are derived and quantified for the nominal case of the ROSETTA spacecraft at the comet Wirtanen. Their effects on the

D. J. Scheeres; F. Marzari; L. Tomasella; V. Vanzani

1998-01-01

278

Selective effect of cinnarizine on the vestibular nucleus neurons  

Microsoft Academic Search

Effects of cinnarizine were studied on the lateral vestibular nucleus (LVN) and spinal trigeminal nucleus (STN) of cats anesthetized with a-chloralose. Cinnarizine did not produce any obvious alterations of the field potential and spike generation of type B interneurons in STN elicited by trigeminal nerve stimulation as well as the field potential in LVN by vestibular nerve stimulation. Spike generation

Sakae Fujimoto; Masashi Sasa; Shuji Takaori; Izuru Matsuoka

1978-01-01

279

Glial Limitans Elasticity Subjacent to the Supraoptic Nucleus  

Microsoft Academic Search

Two previous studies from our laboratory have indicated that the ventral glial limitans subjacent to the hypothalamic supraoptic nucleus (SON-VGL) undergoes a reversible thinning upon chronic activation of the magnocellular neuroendocrine cells (MNCs) of the supraoptic nucleus (SON). Numerous other studies have shown that MNC somata hypertrophy with activation. One aim of the current study was to understand better how

A. K. Salm; N. Hawrylak

2004-01-01

280

The pathways connecting the hippocampal formation, the thalamic reuniens nucleus and the thalamic reticular nucleus in the rat.  

PubMed

Most dorsal thalamic nuclei send axons to specific areas of the neocortex and to specific sectors of the thalamic reticular nucleus; the neocortex then sends reciprocal connections back to the same thalamic nucleus, directly as well indirectly through a relay in the thalamic reticular nucleus. This can be regarded as a 'canonical' circuit of the sensory thalamus. For the pathways that link the thalamus and the hippocampal formation, only a few comparable connections have been described. The reuniens nucleus of the thalamus sends some of its major cortical efferents to the hippocampal formation. The present study shows that cells of the hippocampal formation as well as cells in the reuniens nucleus are retrogradely labelled following injections of horseradish peroxidase or fluoro-gold into the rostral part of the thalamic reticular nucleus in the rat. Within the hippocampal formation, labelled neurons were localized in the subiculum, predominantly on the ipsilateral side, with fewer neurons labelled contralaterally. Labelled neurons were seen in the hippocampal formation and nucleus reuniens only after injections made in the rostral thalamic reticular nucleus (1.6-1.8 mm caudal to bregma). In addition, the present study confirmed the presence of afferent connections to the rostral thalamic reticular nucleus from cortical (cingulate, orbital and infralimbic, retrosplenial and frontal), midline thalamic (paraventricular, anteromedial, centromedial and mediodorsal thalamic nuclei) and brainstem structures (substantia nigra pars reticularis, ventral tegmental area, periaqueductal grey, superior vestibular and pontine reticular nuclei). These results demonstrate a potential for the thalamo-hippocampal circuitry to influence the functional roles of the thalamic reticular nucleus, and show that thalamo-hippocampal connections resemble the circuitry that links the sensory thalamus and neocortex. PMID:18221482

Cavdar, Safiye; Onat, Filiz Y; Cakmak, Yusuf Ozgür; Yananli, Hasan R; Gülçebi, Medine; Aker, Rezzan

2008-03-01

281

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

PubMed

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

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

2014-09-30

282

Video-Assisted Thoracoscopic Surgery under O-Arm Navigation System Guidance for the Treatment of Thoracic Disk Herniations: Surgical Techniques and Early Clinical Results.  

PubMed

This study describes the surgical technique and clinical results of video-assisted thoracoscopic surgery (VATS) assisted by an O-arm-based navigation system, used for the treatment of thoracic disk herniation (TDH). The trend toward the use of minimally invasive procedures with endoscopic visualization of the thoracic cavity in thoracic spine surgery has evolved. It is difficult to develop a new set of visuomotor skills unique to endoscopic procedures and understand the three-dimensional (3D) anatomy while performing a two-dimensional (2D) imaging procedure. Adding image guidance would have a positive impact on these procedures, making them safer and more precise. We report the results of 10 patients who underwent diskectomy for TDH using VATS assisted by an O-arm-based navigation system and describe the surgical technique. The average duration of the symptoms was 2.8 years; average operation time, 326.9 minutes; and average additional time required for the image guidance surgery using the O-arm-based navigation, ? 29.4 minutes. No complications occurred during the surgical procedure or the immediate postoperative period. The advantages of using navigational assistance during the surgical procedure include better visualization of the operative field, more accurate surgical planning, and optimization of the surgical approach involving the establishment of the correct drilling trajectory and safe decompression of the spinal cord, as well as the possibility of intraoperative control of bone resection. PMID:24570307

Hur, Jung-Woo; Kim, Jin-Sung; Cho, Dong-Young; Shin, Jong-Mok; Lee, Jun-Ho; Lee, Sang-Ho

2014-11-01

283

Retrotrapezoid nucleus and parafacial respiratory group  

PubMed Central

The rat retrotrapezoid nucleus (RTN) contains about 2000 Phox2b-expressing glutamatergic neurons (ccRTN neurons; 800 in mice) with a well-understood developmental lineage. ccRTN neuron development fails in mice carrying a Phox2b mutation commonly present in the congenital central hypoventilation syndrome. In adulthood, ccRTN neurons regulate the breathing rate and intensity, and may regulate active expiration along with other neighboring respiratory neurons. Prenatally, ccRTN neurons form an autonomous oscillator (embryonic parafacial group, e-pF) that activates and possibly paces inspiration. The pacemaker properties of the ccRTN neurons probably vanish after birth to be replaced by synaptic drives. The neonatal parafacial respiratory group (pfRG) may represent a transitional phase during which ccRTN neurons lose their group pacemaker properties. ccRTN neurons are activated by acidification via an intrinsic mechanism or via ATP released by glia. In summary, throughout life, ccRTN neurons seem to be a critical hub for the regulation of CO2 via breathing. PMID:20188865

Guyenet, Patrice G.; Mulkey, Daniel K.

2010-01-01

284

Comparing Realistic Subthalamic Nucleus Neuron Models  

NASA Astrophysics Data System (ADS)

The mechanism of action of clinically effective electrical high frequency stimulation is still under debate. However, recent evidence points at the specific activation of GABA-ergic ion channels. Using a computational approach, we analyze temporal properties of the spike trains emitted by biologically realistic neurons of the subthalamic nucleus (STN) as a function of GABA-ergic synaptic input conductances. Our contribution is based on a model proposed by Rubin and Terman and exhibits a wide variety of different firing patterns, silent, low spiking, moderate spiking and intense spiking activity. We observed that most of the cells in our network turn to silent mode when we increase the GABAA input conductance above the threshold of 3.75 mS/cm2. On the other hand, insignificant changes in firing activity are observed when the input conductance is low or close to zero. We thus reproduce Rubin's model with vanishing synaptic conductances. To quantitatively compare spike trains from the original model with the modified model at different conductance levels, we apply four different (dis)similarity measures between them. We observe that Mahalanobis distance, Victor-Purpura metric, and Interspike Interval distribution are sensitive to different firing regimes, whereas Mutual Information seems undiscriminative for these functional changes.

Njap, Felix; Claussen, Jens C.; Moser, Andreas; Hofmann, Ulrich G.

2011-06-01

285

Finite element study of human lumbar disc nucleus replacements.  

PubMed

Currently, there are a number of nucleus replacements under development. The important concern is how well these implants duplicate the mechanical function of the native nucleus. This finite element model study aimed to investigate the influence of different nucleus replacements on the mechanical response of the disc. Models included partial, full, over-sized, partially saturated, elastic and poroelastic solid replacements. Over-sized nucleus replacements up to 25% yielded results that were comparable to those in the intact state. Differences were much greater in cases with under-sized nucleus replacements. The effect was most pronounced for the 75% under-sized replacement that resembled the condition with a full nucleotomy. Nucleus implants with elastic properties substantially altered load transmission when 10% under-sized and over-sized replacements were considered. Compared to intact, the under-sized implants should be avoided when using biphasic materials with properties similar to the native nucleus, whereas for elastic replacements both under- and over-sized implants should not be used. PMID:23477684

Schmidt, Hendrik; Bashkuev, Maxim; Galbusera, Fabio; Wilke, Hans-Joachim; Shirazi-Adl, Aboulfazl

2014-01-01

286

Inputs to the ventrolateral bed nucleus of the stria terminalis.  

PubMed

The ventrolateral bed nucleus of the stria terminalis (BSTvl) receives direct input from two specific subpopulations of neurons in the nucleus tractus solitarius (NTS). It is heavily innervated by aldosterone-sensitive NTS neurons, which are selectively activated by sodium depletion, and by the A2 noradrenergic neurons, which are activated by visceral and immune- and stress-related stimuli. Here, we used a retrograde neuronal tracer to identify other brain sites that innervate the BSTvl. Five general brain regions contained retrogradely labeled neurons: cerebral cortex (infralimbic and insular regions), rostral forebrain structures (subfornical organ, organum vasculosum of the lamina terminalis, taenia tecta, nucleus accumbens, lateral septum, endopiriform nucleus, dorsal BST, substantia innominata, and, most prominently the amygdala--primarily its basomedial and central subnuclei), thalamus (central medial, intermediodorsal, reuniens, and, most prominently the paraventricular thalamic nucleus), hypothalamus (medial preoptic area, perifornical, arcuate, dorsomedial, parasubthalamic, and posterior hypothalamic nuclei), and brainstem (periaqueductal gray matter, dorsal and central superior raphe nuclei, parabrachial nucleus, pre-locus coeruleus region, NTS, and A1 noradrenergic neurons in the caudal ventrolateral medulla). In the arcuate hypothalamic nucleus, some retrogradely labeled neurons contained either agouti-related peptide or cocaine/amphetamine-regulated transcript. Of the numerous retrogradely labeled neurons in the perifornical hypothalamic area, few contained melanin-concentrating hormone or orexin. In the brainstem, many retrogradely labeled neurons were either serotoninergic or catecholaminergic. In summary, the BSTvl receives inputs from a variety of brain sites implicated in hunger, salt and water intake, stress, arousal, and reward. PMID:18853414

Shin, Jung-Won; Geerling, Joel C; Loewy, Arthur D

2008-12-10

287

Afferent projections to nucleus reuniens of the thalamus.  

PubMed

The nucleus reuniens (RE) is the largest of the midline nuclei of the thalamus and the major source of thalamic afferents to the hippocampus and parahippocampal structures. Nucleus reuniens has recently been shown to exert powerful excitatory actions on CA1 of the hippocampus. Few reports on any species have examined afferent projections to nucleus reuniens. By using the retrograde anatomical tracer Fluorogold, we examined patterns of afferent projections to RE in the rat. We showed that RE receives a diverse and widely distributed set of afferents projections. The main sources of input to nucleus reuniens were from the orbitomedial, insular, ectorhinal, perirhinal, and retrosplenial cortices; CA1/subiculum of hippocampus; claustrum, tania tecta, lateral septum, substantia innominata, and medial and lateral preoptic nuclei of the basal forebrain; medial nucleus of amygdala; paraventricular and lateral geniculate nuclei of the thalamus; zona incerta; anterior, ventromedial, lateral, posterior, supramammillary, and dorsal premammillary nuclei of the hypothalamus; and ventral tegmental area, periaqueductal gray, medial and posterior pretectal nuclei, superior colliculus, precommissural/commissural nuclei, nucleus of the posterior commissure, parabrachial nucleus, laterodorsal and pedunculopontine tegmental nuclei, nucleus incertus, and dorsal and median raphe nuclei of the brainstem. The present findings of widespread projections to RE, mainly from limbic/limbic-associated structures, suggest that nucleus reuniens represents a critical relay in the transfer of limbic information (emotional/cognitive) from RE to its major targets, namely, to the hippocampus and orbitomedial prefrontal cortex. RE appears to be a major link in the two-way exchange of information between the hippocampus and the medial prefrontal cortex. PMID:15514932

McKenna, James Timothy; Vertes, Robert P

2004-12-01

288

Observation of the antimatter helium-4 nucleus  

SciTech Connect

High-energy nuclear collisions create an energy density similar to that of the Universe microseconds after the Big Bang; in both cases, matter and antimatter are formed with comparable abundance. However, the relatively short-lived expansion in nuclear collisions allows antimatter to decouple quickly from matter, and avoid annihilation. Thus, a high-energy accelerator of heavy nuclei provides an efficient means of producing and studying antimatter. The antimatter helium-4 nucleus ({sup 4}He), also known as the anti-{alpha} ({alpha}), consists of two antiprotons and two antineutrons (baryon number B = -4). It has not been observed previously, although the {alpha}-particle was identified a century ago by Rutherford and is present in cosmic radiation at the ten per cent level. Antimatter nuclei with B < -1 have been observed only as rare products of interactions at particle accelerators, where the rate of antinucleus production in high-energy collisions decreases by a factor of about 1,000 with each additional antinucleon. Here we report the observation of {sup 4}He, the heaviest observed antinucleus to date. In total, 18 {sup 4}He counts were detected at the STAR experiment at the Relativistic Heavy Ion Collider (RHIC) in 10{sup 9} recorded gold-on-gold (Au+Au) collisions at centre-of-mass energies of 200 GeV and 62 GeV per nucleon-nucleon pair. The yield is consistent with expectations from thermodynamic and coalescent nucleosynthesis models, providing an indication of the production rate of even heavier antimatter nuclei and a benchmark for possible future observations of {sup 4}He in cosmic radiation.

Agakishiev, H.; Tang, A.; et al. (STAR Collaboration)

2011-04-24

289

Vertebral morphology influences the development of Schmorl's nodes in the lower thoracic vertebrae.  

PubMed

Schmorl's nodes are the result of herniations of the nucleus pulposus into the adjacent vertebral body and are commonly identified in both clinical and archaeological contexts. The current study aims to identify aspects of vertebral shape that correlate with Schmorl's nodes. Two-dimensional statistical shape analysis was performed on digital images of the lower thoracic spine (T10-T12) of adult skeletons from the late medieval skeletal assemblages from Fishergate House, York, St. Mary Graces and East Smithfield Black Death cemeteries, London, and postmedieval Chelsea Old Church, London. Schmorl's nodes were scored on the basis of their location, depth, and size. Results indicate that there is a correlation between the shape of the posterior margin of the vertebral body and pedicles and the presence of Schmorl's nodes in the lower thoracic spine. The size of the vertebral body in males was also found to correlate with the lesions. Vertebral shape differences associated with the macroscopic characteristics of Schmorl's nodes, indicating severity of the lesion, were also analyzed. The shape of the pedicles and the posterior margin of the vertebral body, along with a larger vertebral body size in males, have a strong association with both the presence and severity of Schmorl's nodes. This suggests that shape and/or size of these vertebral components are predisposing to, or resulting in, vertically directed disc herniation. PMID:23097159

Plomp, Kimberly A; Roberts, Charlotte A; Viðarsdóttir, Una Strand

2012-12-01

290

Energy-Dependence of Nucleus-Nucleus Potential and Friction Parameter in Fusion Reactions  

E-print Network

Applying a macroscopic reduction procedure on the improved quantum molecular dynamics (ImQMD), the energy dependences of the nucleus-nucleus potential, the friction parameter, and the random force characterizing a one-dimensional Langevin-type description of the heavy-ion fusion process are investigated. Systematic calculations with the ImQMD show that the fluctuation-dissipation relation found in the symmetric head-on fusion reactions at energies just above the Coulomb barrier fades out when the incident energy increases. It turns out that this dynamical change with increasing incident energy is caused by a specific behavior of the friction parameter which directly depends on the microscopic dynamical process, i.e., on how the collective energy of the relative motion is transferred into the intrinsic excitation energy. It is shown microscopically that the energy dissipation in the fusion process is governed by two mechanisms: One is caused by the nucleon exchanges between two fusing nuclei, and the other is ...

Wen, Kai; Li, Zhu-Xia; Wu, Xi-Zhen; Zhang, Ying-Xun; Zhou, Shan-Gui

2014-01-01

291

Energy-Dependence of Nucleus-Nucleus Potential and Friction Parameter in Fusion Reactions  

E-print Network

Applying a macroscopic reduction procedure on the improved quantum molecular dynamics (ImQMD) model, the energy dependences of the nucleus-nucleus potential, the friction parameter, and the random force characterizing a one-dimensional Langevin-type description of the heavy-ion fusion process are investigated. Systematic calculations with the ImQMD model show that the fluctuation-dissipation relation found in the symmetric head-on fusion reactions at energies just above the Coulomb barrier fades out when the incident energy increases. It turns out that this dynamical change with increasing incident energy is caused by a specific behavior of the friction parameter which directly depends on the microscopic dynamical process, i.e., on how the collective energy of the relative motion is transferred into the intrinsic excitation energy. It is shown microscopically that the energy dissipation in the fusion process is governed by two mechanisms: One is caused by the nucleon exchanges between two fusing nuclei, and the other is due to a rearrangement of nucleons in the intrinsic system. The former mechanism monotonically increases the dissipative energy and shows a weak dependence on the incident energy, while the latter depends on both the relative distance between two fusing nuclei and the incident energy. It is shown that the latter mechanism is responsible for the energy dependence of the fusion potential and explains the fading out of the fluctuation-dissipation relation.

Kai Wen; Fumihiko Sakata; Zhu-Xia Li; Xi-Zhen Wu; Ying-Xun Zhang; Shan-Gui Zhou

2014-07-22

292

Statistical analysis of secondary particle distributions in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

The use is described of several statistical techniques to characterize structure in the angular distributions of secondary particles from nucleus-nucleus collisions in the energy range 24 to 61 GeV/nucleon. The objective of this work was to determine whether there are correlations between emitted particle intensity and angle that may be used to support the existence of the quark gluon plasma. The techniques include chi-square null hypothesis tests, the method of discrete Fourier transform analysis, and fluctuation analysis. We have also used the method of composite unit vectors to test for azimuthal asymmetry in a data set of 63 JACEE-3 events. Each method is presented in a manner that provides the reader with some practical detail regarding its application. Of those events with relatively high statistics, Fe approaches 0 at 55 GeV/nucleon was found to possess an azimuthal distribution with a highly non-random structure. No evidence of non-statistical fluctuations was found in the pseudo-rapidity distributions of the events studied. It is seen that the most effective application of these methods relies upon the availability of many events or single events that possess very high multiplicities.

Mcguire, Stephen C.

1987-01-01

293

Nucleus-nucleus cold fusion reactions analyzed with the l-dependent ``fusion by diffusion'' model  

NASA Astrophysics Data System (ADS)

We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section ?cap(l), the fusion probability Pfus(l), and the survival probability Psurv(l). The fusion hindrance factor, the inverse of Pfus(l), is treated in terms of thermal fluctuations in the shape degrees of freedom and is expressed as a solution of the Smoluchowski diffusion equation. The l dependence of Pfus(l) results from the l-dependent potential energy surface of the colliding system. A new parametrization of the distance of starting point of the diffusion process is introduced. An analysis of a complete set of 27 excitation functions for production of superheavy nuclei in cold fusion reactions, studied in experiments at GSI Darmstadt, RIKEN Tokyo, and LBNL Berkeley, is presented. The FBD model satisfactorily reproduces shapes and absolute cross sections of all the cold fusion excitation functions. It is shown that the peak position of the excitation function for a given 1n reaction is determined by the Q value of the reaction and the height of the fission barrier of the final nucleus. This fact could possibly be used in future experiments (with well-defined beam energy) for experimental determination of the fission barrier heights.

Cap, T.; Siwek-Wilczy?ska, K.; Wilczy?ski, J.

2011-05-01

294

Pion production at 180/sup 0/ in nucleus-nucleus collisions  

SciTech Connect

A survey experiment of pion production at 180/sup 0/ in nucleus-nucleus collisions is presented. Beams of 1.05 GeV/A and 2.1 GeV/A protons, alphas, and carbon were used, as well as proton beams of 0.80 GeV, 3.5 GeV, and 4.89 GeV, and argon beams of 1.05 GeV/A and 1.83 GeV/A. This is the first such experiment to use the heavier beams. Targets used ranged from carbon to lead. An in-depth review of the literature, both experimental and theoretical, is also presented. The systematics of the data are discussed, and comparisons are made both with prior experiments and with the predictions of the models reviewed. The cross sections appear consistent with a simple single nucleon-nucleon collision picture, without the need for collective or other exotic effects. Suggestions for future work are made.

Chessin, S.A.

1983-05-01

295

Glutamate Inputs to the Nucleus Accumbens: Does Source Matter?  

E-print Network

How the nucleus accumbens integrates information from multiple upstream regions has been a central question for decades. In this issue of Neuron, Britt et al. (2012) photostimulate glutamatergic axons from the amygdala, ...

Tye, Kay

296

Cytotoxicity of nucleus-targeting fluorescent gold nanoclusters  

NASA Astrophysics Data System (ADS)

Gold nanoclusters (AuNCs) with ultra small sizes and unique fluorescence properties have shown promising potential for imaging the nuclei of living cells. However, little is known regarding the potential cytotoxicity of AuNCs after they enter the cell nucleus. The aim of this study is to investigate whether and how nucleus-targeting AuNCs affect the normal functioning of cells. Highly stable, water-soluble and bright fluorescent Au25NCs (the core of each nanocluster is composed of 25 gold atoms) were synthesized. Specific targeting of Au25NCs to the cell nucleus was achieved by conjugating the TAT peptide to the Au25NCs. Cell viability, cell morphology, cell apoptosis/necrosis, reactive oxygen species (ROS) level and mitochondrial membrane potential examinations were performed on different cell lines exposed to the nucleus-targeting Au25NCs. We found that the nucleus-targeting Au25NCs caused cell apoptosis in a dose-dependent manner. A possible mechanism for the cytotoxicity of the nucleus-targeting Au25NCs was proposed as follows: the nucleus-targeting Au25NCs induce the production of ROS, resulting in the oxidative degradation of mitochondrial components, in turn leading to apoptosis via a mitochondrial damage pathway. This work facilitates a better understanding of the toxicity of AuNCs, especially nucleus-targeting AuNCs.Gold nanoclusters (AuNCs) with ultra small sizes and unique fluorescence properties have shown promising potential for imaging the nuclei of living cells. However, little is known regarding the potential cytotoxicity of AuNCs after they enter the cell nucleus. The aim of this study is to investigate whether and how nucleus-targeting AuNCs affect the normal functioning of cells. Highly stable, water-soluble and bright fluorescent Au25NCs (the core of each nanocluster is composed of 25 gold atoms) were synthesized. Specific targeting of Au25NCs to the cell nucleus was achieved by conjugating the TAT peptide to the Au25NCs. Cell viability, cell morphology, cell apoptosis/necrosis, reactive oxygen species (ROS) level and mitochondrial membrane potential examinations were performed on different cell lines exposed to the nucleus-targeting Au25NCs. We found that the nucleus-targeting Au25NCs caused cell apoptosis in a dose-dependent manner. A possible mechanism for the cytotoxicity of the nucleus-targeting Au25NCs was proposed as follows: the nucleus-targeting Au25NCs induce the production of ROS, resulting in the oxidative degradation of mitochondrial components, in turn leading to apoptosis via a mitochondrial damage pathway. This work facilitates a better understanding of the toxicity of AuNCs, especially nucleus-targeting AuNCs. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr04227a

Zhao, Jing-Ya; Cui, Ran; Zhang, Zhi-Ling; Zhang, Mingxi; Xie, Zhi-Xiong; Pang, Dai-Wen

2014-10-01

297

Chandra unveils a binary active galactic nucleus in Mrk 463  

NASA Astrophysics Data System (ADS)

We analyse Chandra, XMM-Newton and Hubble Space Telescope (HST) data of the double-nucleus Ultraluminous Infrared Galaxy (ULIRG), Mrk 463. The Chandra detection of two luminous (L2-10keV = 1.5 × 1043 and 3.8 × 1042 erg cm-2 s-1), unresolved nuclei in Mrk 463 indicates that this galaxy hosts a binary active galactic nucleus (AGN), with a projected separation of ~=3.8 kpc (3.83 +/- 0.01 arcsec). While the East nucleus was already known to be a type 2 Seyfert (and this is further confirmed by our Chandra detection of a neutral iron line), this is the first unambiguous evidence in favour of the AGN nature of the West nucleus. Mrk 463 is therefore the clearest case so far for a binary AGN, after NGC 6240.

Bianchi, Stefano; Chiaberge, Marco; Piconcelli, Enrico; Guainazzi, Matteo; Matt, Giorgio

2008-05-01

298

Deconvolving the Nucleus of Centaurus A Using Chandra PSF Library  

NASA Technical Reports Server (NTRS)

Centaurus A (NGC 5128) is a giant early-type galaxy containing the nearest (at 3.5 Mpc) radio-bright Active Galactic Nucleus (AGN). Cen A was observed with the High Resolution Camera (HRC) on the Chandra X-ray Observatory on several occasions since the launch in July 1999. The high-angular resolution (less than 0.5 arcsecond) Chandra/HRC images reveal X ray multi-scale structures in this object with unprecedented detail and clarity, including the bright nucleus believed to be associated with a supermassive black hole. We explored the spatial extent of the Cen A nucleus using deconvolution techniques on the full resolution Chandra images. Model point spread functions (PSFs) were derived from the standard Chandra raytrace PSF library as well as unresolved point sources observed with Chandra. The deconvolved images show that the Cen A nucleus is resolved and asymmetric. We discuss several possible causes of this extended emission and of the asymmetries.

Karovska, Margarita

2000-01-01

299

Neutrino-nucleus reactions in the delta resonance region  

E-print Network

Reliable estimates of neutrino-nucleus reactions in the resonance-excitation region play an important role in many of the on-going and planned neutrino oscillation experiments. We study here neutrino-nucleus reactions in the delta-particle excitation region with the use of neutrino pion-production amplitudes calculated in a formalism in which the resonance contributions and the background amplitudes are treated on the same footing. Our approach leads to the neutrino-nucleus reaction cross sections that are significantly different from those obtained in the conventional approach wherein only the pure resonance amplitudes are taken into account. To assess the reliability of our formalism, we calculate the electron-nucleus scattering cross sections in the same theoretical framework; the calculated cross sections agree reasonably well with the existing data.

B. Szczerbinska; T. Sato; K. Kubodera; T. -S. H. Lee

2006-10-25

300

Melatonin modulates intercellular communication among immortalized rat suprachiasmatic nucleus cells  

E-print Network

anlage of the rat suprachiasmatic nucleus, as an in vitro model system to study intercellular communication among SCN cells. I tested whether the pineal neurohormone melatonin could modulate cell-to-cell signaling, via both dye coupling (gap junctional...

Cox, Kimberly Yvonne

2009-05-15

301

Influence of the nucleon-nucleon collision geometry on the determination of the nuclear modification factor for nucleon-nucleus and nucleus-nucleus collisions  

SciTech Connect

The influence of the underlying nucleon-nucleon collision geometry on evaluations of the nuclear overlap function (TAB) and number of binary collisions (Ncoll) is studied. A narrowing of the spatial distribution of the hard-partons with large light-cone fraction x in nucleons leads to a downward correction for Ncoll and TAB, which in turn, results in an upward correction for the nuclear modification factor RAB. The size of this correction is estimated for several experimentally motivated nucleon-nucleon overlap functions for hard-partons. It is found to be significant in peripheral nucleus-nucleus and nucleon-nucleus collisions, and is much larger at the LHC energy of {radical}s = 5.5 TeV than for the RHIC energy of {radical}s = 200 GeV. The implications for experimental measurements are also discussed.

Jia, J.i.

2009-11-01

302

Negative binomial distribution for hadron-nucleus interactions  

NASA Astrophysics Data System (ADS)

Assuming the validity of the negative binomial distribution for hadron-nucleus interactions, the Singh-Uddin-Kamal relation between the two parameters k Aandn¯s of the distribution is derived and is found to be universally valid for proton-proton as well as proton-nucleus interactions at high energy. We further deduce the target-mass number dependence and the energy dependence of the parameter kA.

Singh, C. P.; Shyam, M.; Uddin, Saeed

1991-01-01

303

The nucleus N. trochlearis of the adult deer, Odocoileus virginianus  

E-print Network

THE NUCLEUS N, TROCHLEARIS OP THE ADULT DEER, ODOCOILEUS VIRGIHIAHUS A Thesis Presented to the Graduate College of the Texas A&M University In Partial Fulfillment of the Requirements for the Degree of Master of Science in Veterinary Anatomy... by Tofayel Hoesain Sarkar January 1964 THE NUCLEUS N. TROCHLEARIS OF THE ADULT DEER& ODOCOILEUS VIRGINIANUS A Thesis By Tofayel Hossain Barker Approved as to style and content by: Nemb s of the Cosssgttee: Chai'rman of Cosssit tee / / grat rll g...

Sarkar, Tofayel Hossain

2012-06-07

304

Mission CaMKII?: Shuttle Calmodulin from Membrane to Nucleus.  

PubMed

Neuronal plasticity depends on plasma membrane Ca(2+) influx, resulting in activity-dependent gene transcription. Calmodulin (CaM) activated by Ca(2+) initiates the nuclear events, but how CaM makes its way to the nucleus has remained elusive. Ma et al. now show that CaMKII? transports CaM from cell surface Ca(2+) channels to the nucleus. PMID:25303520

Malik, Zulfiqar A; Stein, Ivar S; Navedo, Manuel F; Hell, Johannes W

2014-10-01

305

Acts and knowledge management in the NUCLEUS hospital information system.  

PubMed Central

NUCLEUS is a project completed in June 1995 in the frame of the European Community programme AIM (Advanced Informatics in Medicine). The main result of NUCLEUS is a prototype of an integrated patient dossier. Together with this patient dossier, facilities have been developed for its customisation by the various categories of end-users. A semantic model has been designed to guide and control the exploitation of data, and ensures the overall integrity of the information system. PMID:8563297

Kanoui, H.; Joubert, M.; Favard, R.; Maury, G.; Pelletier, M.

1995-01-01

306

[Occlusion of a perforating artery, by descending tentorial herniation after head injury, supplying deep cerebral structure--report of 4 cases and their CT evaluation].  

PubMed

Four cases with descending tentorial herniation (DTH) after head injury which showed thalamic, mesencephalic and basal ganglionic low density areas (LDAs) manifesting a infarction in postoperative CT films are reported, and a possible mechanism are discussed in this paper. Case 1: Bilateral acute subdural hematoma with left DTH showed LDAs in the anterior part of the bilateral thalami, left occipital lobe and midbrain. The estimated occluded arteries included the anterior thalamoperforating artery(AThA), posterior cerebral artery and midbrain perforator. Case 2: Right acute epidural hematoma with DTH showed LDAs in the anterior part of the right thalamus and in the left globus pallidus. The estimated occluded arteries included the AThA and anterior choroidal artery. Case 3: Right acute epidural hematoma with DTH showed LDAs in the anterior part of the left thalamus, and in the left midbrain tegmentum. The estimated occluded artery was the interpeduncular thalamoperforating artery (IThA). Case 4: Right chronic subdural hematoma with DTH showed LDA mainly in the left thalamus except for the superior thalamic region. The estimated occluded arteries included the AThA and/or IThA and thalamogeniculate artery. Cases 1 and 4 were adult males and cases 2 and 3 were infant males, and the prognosis was good in the infant males, and poor in the adult males. Each of the 4 cases showed no loss of consciousness just after the head injury while 3 out of them deteriorated within several hours, and one was a case of chronic subdural hematoma.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3248192

Niikawa, S; Uno, T; Ohkuma, A; Hara, A; Nokura, H; Yamada, H

1988-12-01

307

Formation of dense partonic matter in relativistic nucleus–nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration  

Microsoft Academic Search

Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta (pT), elliptic flow, two-particle correlations, nonstatistical fluctuations,

K. Adcox; S. S. Adler; S. Afanasiev; C. Aidala; N. N. Ajitanand; Y. Akiba; A. Al-Jamel; J. Alexander; R. Amirikas; K. Aoki; L. Aphecetche; Y. Arai; R. Armendariz; S. H. Aronson; R. Averbeck; T. C. Awes; R. Azmoun; V. Babintsev; A. Baldisseri; K. N. Barish; P. D. Barnes; J. Barrette; B. Bassalleck; S. Bathe; S. Batsouli; V. Baublis; F. Bauer; A. Bazilevsky; S. Belikov; F. G. Bellaiche; S. T. Belyaev; M. J. Bennett; Y. Berdnikov; S. Bhagavatula; M. T. Bjorndal; J. G. Boissevain; H. Borel; S. Borenstein; M. L. Brooks; D. S. Brown; N. Bruner; D. Bucher; H. Buesching; V. Bumazhnov; G. Bunce; J. M. Burward-Hoy; S. Butsyk; X. Camard; T. A. Carey; J.-S. Chai; P. Chand; J. Chang; W. C. Chang; L. L. Chavez; S. Chernichenko; C. Y. Chi; J. Chiba; M. Chiu; I. J. Choi; R. K. Choudhury; T. Christ; M. S. Chung; P. Chung; V. Cianciolo; C. R. Cleven; Y. Cobigo; B. A. Cole; M. P. Comets; P. Constantin; M. Csanád; T. Csörg?; J. P. Cussonneau; D. d'Enterria; T. Dahms; K. Das; G. David; F. Deák; H. Delagrange; A. Denisov; A. Deshpande; E. J. Desmond; A. Devismes; O. Dietzsch; B. V. Dinesh; J. L. Drachenberg; O. Drapier; A. Drees; A. K. Dubey; R. du Rietz; A. Durum; D. Dutta; V. Dzhordzhadze; K. Ebisu; Y. V. Efremenko; J. Egdemir; K. El Chenawi; A. Enokizono; H. En'yo; B. Espagnon; S. Esumi; L. Ewell; T. Ferdousi; D. E. Fields; C. Finck; F. Fleuret; S. L. Fokin; B. Forestier; Z. Fraenkel; J. E. Frantz; A. Franz; A. D. Frawley; Y. Fukao; S.-Y. Fung; S. Gadrat; S. Garpman; F. Gastineau; M. Germain; T. K. Ghosh; A. Glenn; A. L. Godoi; G. Gogiberidze; M. Gonin; J. Gosset; Y. Goto; R. Granier de Cassagnac; N. Grau; S. V. Greene; M. Grosse Perdekamp; T. Gunji; S. K. Gupta; W. Guryn; H.-Å. Gustafsson; T. Hachiya; A. Hadjhenni; J. S. Haggerty; M. N. Hagiwara; H. Hamagaki; A. G. Hansen; H. Hara; H. Harada; E. P. Hartouni; K. Haruna; M. Harvey; E. Haslum; K. Hasuko; R. Hayano; N. Hayashi; X. He; M. Heffner; T. K. Hemmick; J. M. Heuser; P. Hidas; H. Hiejima; J. C. Hill; D. S. Ho; R. Hobbs; M. Holmes; W. Holzmann; K. Homma; B. Hong; A. Hoover; T. Horaguchi; H. M. Hur; T. Ichihara; V. V. Ikonnikov; K. Imai; M. Inaba; M. Inuzuka; M. S. Ippolitov; D. Isenhower; L. Isenhower; M. Ishihara; T. Isobe; M. Issah; A. Isupov; B. V. Jacak; W. Y. Jang; J. Jia; O. Jinnouchi; B. M. Johnson; S. C. Johnson; K. S. Joo; D. Jouan; F. Kajihara; S. Kametani; N. Kamihara; M. Kaneta; J. H. Kang; M. Kann; S. S. Kapoor; K. Katou; T. Kawabata; T. Kawagishi; A. V. Kazantsev; S. Kelly; B. Khachaturov; A. Khanzadeev; J. Kikuchi; D. H. Kim; D. J. Kim; D. W. Kim; E. Kim; G.-B. Kim; H. J. Kim; S. Y. Kim; Y. G. Kim; E. Kinney; W. W. Kinnison; A. Kiss; E. Kistenev; A. Kiyomichi; K. Kiyoyama; C. Klein-Boesing; S. Klinksiek; H. Kobayashi; L. Kochenda; V. Kochetkov; D. Koehler; T. Kohama; R. Kohara; B. Komkov; M. Konno; M. Kopytine; D. Kotchetkov; A. Kozlov; P. J. Kroon; C. H. Kuberg; G. J. Kunde; N. Kurihara; K. Kurita; Y. Kuroki; M. J. Kweon; Y. Kwon; G. S. Kyle; R. Lacey; V. Ladygin; J. G. Lajoie; J. Lauret; Y. Le Bornec; A. Lebedev; S. Leckey; D. M. Lee; S. Lee; M. J. Leitch; M. A. L. Leite; X. H. Li; Z. Li; D. J. Lim; H. Lim; A. Litvinenko; M. X. Liu; X. Liu; X. Liu; Z. Liu; C. F. Maguire; J. Mahon; Y. I. Makdisi; A. Malakhov; M. D. Malik; V. I. Manko; Y. Mao; S. K. Mark; S. Markacs; G. Martinez; M. D. Marx; A. Masaike; H. Masui; F. Matathias; T. Matsumoto; M. C. McCain; P. L. McGaughey; E. Melnikov; M. Merschmeyer; F. Messer; M. Messer; Y. Miake; J. Milan; T. E. Miller; A. Milov; S. Mioduszewski; R. E. Mischke; G. C. Mishra; J. T. Mitchell; A. K. Mohanty; D. P. Morrison; J. M. Moss; T. V. Moukhanova; F. Mühlbacher; D. Mukhopadhyay; M. Muniruzzaman; J. Murata; S. Nagamiya; Y. Nagasaka; J. L. Nagle; M. Naglis; Y. Nakada; T. Nakamura; B. K. Nandi; M. Nara; J. Newby; M. Nguyen; L. Nikkinen; P. Nilsson; S. Nishimura; B. Norman; A. S. Nyanin; J. Nystrand; E. O'Brien; C. A. Ogilvie; H. Ohnishi; I. D. Ojha; H. Okada; K. Okada; O. O. Omiwade; M. Ono; V. Onuchin; A. Oskarsson; L. Österman; I. Otterlund; K. Oyama; L. Paffrath; D. Pal; A. P. T. Palounek; V. Pantuev; V. Papavassiliou; W. J. Park; A. Parmar; S. F. Pate; H. Pei; T. Peitzmann; V. Penev; J.-C. Peng; H. Pereira; V. Peresedov; D. Yu. Peressounko; A. N. Petridis; A. Pierson; C. Pinkenburg; R. P. Pisani; F. Plasil; M. Pollack; K. Pope; M. L. Purschke; A. K. Purwar; H. Qu; J. M. Qualls; J. Rak; I. Ravinovich; K. F. Read; M. Reuter; K. Reygers; V. Riabov; G. Roche; A. Romana; M. Rosati; A. A. Rose; S. S. E. Rosendahl; P. Rosnet; P. Rukoyatkin; V. L. Rykov; S. S. Ryu; M. E. Sadler; B. Sahlmueller; N. Saito; A. Sakaguchi; T. Sakaguchi; M. Sakai; S. Sakai; H. Sako; T. Sakuma; V. Samsonov; L. Sanfratello; T. C. Sangster; R. Santo; H. D. Sato; S. Sato; S. Sawada; B. R. Schlei; Y. Schutz; V. Semenov; R. Seto; D. Sharma; M. R. Shaw; T. K. Shea; I. Shein; T.-A. Shibata; K. Shigaki; T. Shiina

2005-01-01

308

Role of the central amygdaloid nucleus in shaping the discharge of gustatory neurons in the rat parabrachial nucleus  

Microsoft Academic Search

The central amygdaloid nucleus (CeA) receives projection from the parabrachial nucleus (PBN) gustatory neurons and descendingly projects to the PBN. To assess if the CeA is involved in modulating the activity of gustatory neurons in the PBN, the effects of electrical stimulation and electrolytic lesion of CeA on PBN gustatory neurons were observed. Of 60 neurons observed, 30 were classified

Tao Huang; Jianqun Yan; Yi Kang

2003-01-01

309

Stopping powers and cross sections due to two-photon processes in relativistic nucleus-nucleus collisions  

NASA Technical Reports Server (NTRS)

The effects of electromagnetic-production processes due to two-photon exchange in nucleus-nucleus collisions are discussed. Feynman diagrams for two-photon exchange are evaluated using quantum electrodynamics. The total cross section and stopping power for projectile and target nuclei of identical charge are found to be significant for heavy nuclei above a few GeV per nucleon-incident energy.

Cheung, Wang K.; Norbury, John W.

1994-01-01

310

Nucleus-nucleus cold fusion reactions analyzed with the l-dependent 'fusion by diffusion' model  

SciTech Connect

We present a modified version of the Fusion by Diffusion (FBD) model aimed at describing the synthesis of superheavy nuclei in cold fusion reactions, in which a low excited compound nucleus emits only one neutron. The modified FBD model accounts for the angular momentum dependence of three basic factors determining the evaporation residue cross section: the capture cross section {sigma}{sub cap}(l), the fusion probability P{sub fus}(l), and the survival probability P{sub surv}(l). The fusion hindrance factor, the inverse of P{sub fus}(l), is treated in terms of thermal fluctuations in the shape degrees of freedom and is expressed as a solution of the Smoluchowski diffusion equation. The l dependence of P{sub fus}(l) results from the l-dependent potential energy surface of the colliding system. A new parametrization of the distance of starting point of the diffusion process is introduced. An analysis of a complete set of 27 excitation functions for production of superheavy nuclei in cold fusion reactions, studied in experiments at GSI Darmstadt, RIKEN Tokyo, and LBNL Berkeley, is presented. The FBD model satisfactorily reproduces shapes and absolute cross sections of all the cold fusion excitation functions. It is shown that the peak position of the excitation function for a given 1n reaction is determined by the Q value of the reaction and the height of the fission barrier of the final nucleus. This fact could possibly be used in future experiments (with well-defined beam energy) for experimental determination of the fission barrier heights.

Cap, T.; Siwek-Wilczynska, K.; Wilczynski, J. [Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Hoza 69, PL-00-681 Warsaw (Poland); Andrzej Soltan Institute for Nuclear Studies, PL-05-400 Otwock-Swierk (Poland)

2011-05-15

311

PREFACE: 11th International Conference on Nucleus-Nucleus Collisions (NN2012)  

NASA Astrophysics Data System (ADS)

The 11th International Conference on Nucleus-Nucleus Collisions (NN2012) was held from 27 May to 1 June 2012, in San Antonio, Texas, USA. It was jointly organized and hosted by The Cyclotron Institute at Texas A&M University, College Station and The Department of Physics and Astronomy at Texas A&M University-Commerce. Among the approximately 300 participants were a large number of graduate students and post-doctoral fellows. The Keynote Talk of the conference, 'The State of Affairs of Present and Future Nucleus-Nucleus Collision Science', was given by Dr Robert Tribble, University Distinguished Professor and Director of the TAMU Cyclotron Institute. During the conference a very well-received public lecture on neutrino astronomy, 'The ICEcube project', was given by Dr Francis Halzen, Hilldale and Gregory Breit Distinguished Professor at the University of Wisconsin, Madison. The Scientific program continued in the general spirit and intention of this conference series. As is typical of this conference a broad range of topics including fundamental areas of nuclear dynamics, structure, and applications were addressed in 42 plenary session talks, 150 parallel session talks, and 21 posters. The high quality of the work presented emphasized the vitality and relevance of the subject matter of this conference. Following the tradition, the NN2012 International Advisory Committee selected the host and site of the next conference in this series. The 12th International Conference on Nucleus-Nucleus Collisions (NN2015) will be held 21-26 June 2015 in Catania, Italy. It will be hosted by The INFN, Laboratori Nazionali del Sud, INFN, Catania and the Dipartimento di Fisica e Astronomia of the University of Catania. The NN2012 Proceedings contains the conference program and 165 articles organized into the following 10 sections 1. Heavy and Superheavy Elements 2. QCD and Hadron Physics 3. Relativistic Heavy-Ion Collisions 4. Nuclear Structure 5. Nuclear Energy and Applications of Nuclear Science and Technologies 6. Nuclear Reactions and Structure of Unstable Nuclei 7. Equation of State of Neutron-Rich Nuclear Matter, Clusters in Nuclei and Nuclear Reactions 8. Fusion and Fission 9. Nuclear Astrophysics 10. New Facilities and Detectors We would like to thank Texas A&M University and Texas A&M University-Commerce for their organizational support and for providing financial support for many students and postdocs and those who had special need. This support helped assure the success of NN2012. Special thanks also go to all members of the International Advisory Committee and the Local Organizing Committee (listed below) for their great work in advising upon, preparing and executing the NN2012 scientific program as well as the social events that all together made the NN2012 an enjoyable experience for both the participants and their companions. NN2012 International Advisory Committee N Auerbach (Israel) J Aysto (Finland) C Beck (France) S Cherubini (Italy) L Ferreira (Portugal) C Gagliardi (USA) S Gales (France) C Gale (Canada) W Gelletly (Great Britain) Paulo R S Gomes (Brazil) W Greiner (Germany) W Henning (USA) D Hinde (Australia) S Hofmann (Germany) M Hussein (Brazil) B Jacak (USA) S Kailas (India) W G Lynch (USA) Z Majka (Poland) L McLerran (USA) V Metag (Germany) K Morita (Japan) B Mueller (USA) D G Mueller (France) T Motobayashi (Japan) W Nazarewicz (USA) Y Oganessian (Russia) J Nolen (USA) E K Rehm (USA) N Rowley (France) B Sherrill (USA) J Schukraft (Switzerland) W Q Shen (China) A Stefanini (Italy) H Stoecker (Germany) A Szanto de Toledo (Brazil) U van Kolck (USA) W von Oertzen (Germany) M Wiescher (USA) N Xu (USA) N V Zamfir (Romania) W L Zhan (China) H Q Zhang (China) NN2012 Local Organizing Committee Marina Barbui Carlos Bertulani Robert Burch Jr Cheri Davis Cody Folden Kris Hagel John Hardy Bao-An Li (Co-Chair and Scientific Secretary) Joseph Natowitz (Co-Chair) Ralf Rapp Livius Trache Sherry Yennello Editors of NN2012 Proceedings Bao-An Li (Texas A&M University-Commerce) and Joseph Natowitz (Texas A&M Unive

Li, Bao-An; Natowitz, Joseph B.

2013-03-01

312

Heterogeneous calretinin expression in the avian cochlear nucleus angularis.  

PubMed

Multiple calcium-binding proteins (CaBPs) are expressed at high levels and in complementary patterns in the auditory pathways of birds, mammals, and other vertebrates, but whether specific members of the CaBP family can be used to identify neuronal subpopulations is unclear. We used double immunofluorescence labeling of calretinin (CR) in combination with neuronal markers to investigate the distribution of CR-expressing neurons in brainstem sections of the cochlear nucleus in the chicken (Gallus gallus domesticus). While CR was homogeneously expressed in cochlear nucleus magnocellularis, CR expression was highly heterogeneous in cochlear nucleus angularis (NA), a nucleus with diverse cell types analogous in function to neurons in the mammalian ventral cochlear nucleus. To quantify the distribution of CR in the total NA cell population, we used antibodies against neuronal nuclear protein (NeuN), a postmitotic neuron-specific nuclear marker. In NA neurons, NeuN label was variably localized to the cell nucleus and the cytoplasm, and the intensity of NeuN immunoreactivity was inversely correlated with the intensity of CR immunoreactivity. The percentage of CR?+?neurons in NA increased from 31 % in embryonic (E)17/18 chicks, to 44 % around hatching (E21), to 51 % in postnatal day (P) 8 chicks. By P8, the distribution of CR?+?neurons was uniform, both rostrocaudal and in the tonotopic (dorsoventral) axis. Immunoreactivity for the voltage-gated potassium ion channel Kv1.1, used as a marker for physiological type, showed broad and heterogeneous postsynaptic expression in NA, but did not correlate with CR expression. These results suggest that CR may define a subpopulation of neurons within nucleus angularis. PMID:24752525

Bloom, S; Williams, A; MacLeod, K M

2014-08-01

313

The subthalamic nucleus influences visuospatial attention in humans.  

PubMed

Spatial attention is a lateralized feature of the human brain. Whereas the role of cortical areas of the nondominant hemisphere on spatial attention has been investigated in detail, the impact of the BG, and more precisely the subthalamic nucleus, on signs and symptoms of spatial attention is not well understood. Here we used unilateral deep brain stimulation of the subthalamic nucleus to reversibly, specifically, and intraindividually modify the neuronal BG outflow and its consequences on signs and symptoms of visuospatial attention in patients suffering from Parkinson disease. We tested 13 patients with Parkinson disease and chronic deep brain stimulation in three stimulation settings: unilateral right and left deep brain stimulation of the subthalamic nucleus as well as bilateral deep brain stimulation of the subthalamic nucleus. In all three stimulation settings, the patients viewed a set of pictures while an eye-tracker system recorded eye movements. During the exploration of the visual stimuli, we analyzed the time spent in each visual hemispace, as well as the number, duration, amplitude, peak velocity, acceleration peak, and speed of saccades. In the unilateral left-sided stimulation setting, patients show a shorter ipsilateral exploration time of the extrapersonal space, whereas number, duration, and speed of saccades did not differ between the different stimulation settings. These results demonstrated reduced visuospatial attention toward the side contralateral to the right subthalamic nucleus that was not being stimulated in a unilateral left-sided stimulation. Turning on the right stimulator, the reduced visuospatial attention vanished. These results support the involvement of the subthalamic nucleus in modulating spatial attention. Therefore, the subthalamic nucleus is part of the subcortical network that subserves spatial attention. PMID:24144249

Schmalbach, Barbara; Günther, Veronika; Raethjen, Jan; Wailke, Stefanie; Falk, Daniela; Deuschl, Günther; Witt, Karsten

2014-03-01

314

Acto-Myosin Contractility Rotates the Cell Nucleus  

NASA Astrophysics Data System (ADS)

The nucleus of the eukaryotic cell functions amidst active cytoskeletal filaments, but its response to the stresses carried by these filaments is largely unexplored. We report here the results of studies of the translational and rotational dynamics of the nuclei of single fibroblast cells, with the effects of cell migration suppressed by plating onto fibronectin-coated micro-fabricated patterns. Patterns of the same area but different shapes and/or aspect ratio were used to study the effect of cell geometry on the dynamics. On circles, squares and equilateral triangles, the nucleus undergoes persistent rotational motion, while on high-aspect-ratio rectangles of the same area it moves only back and forth. The circle and the triangle showed respectively the largest and the smallest angular speed. We show that our observations can be understood through a hydrodynamic approach in which the nucleus is treated as a highly viscous inclusion residing in a less viscous fluid of orientable filaments endowed with active stresses. Lowering actin contractility selectively by introducing blebbistatin at low concentrations drastically reduced the speed and persistence time of the angular motion of the nucleus. Time-lapse imaging of actin revealed a correlated hydrodynamic flow around the nucleus, with profile and magnitude consistent with the results of our theoretical approach. Coherent intracellular flows and consequent nuclear rotation thus appear to be a generic property that cells must balance by specific mechanisms in order to maintain nuclear homeostasis.

Kumar, Abhishek; Maitra, Ananyo; Sumit, Madhuresh; Ramaswamy, Sriram; Shivashankar, G. V.

2013-01-01

315

Spectroscopy of the neutron-deficient nucleus Os16791  

NASA Astrophysics Data System (ADS)

Excited states of the nucleus Os167 have been populated by the reaction Mo92(Kr78,2pn). The JUROGAM ?-ray detector array has been used in conjunction with the RITU gas-filled separator and the GREAT spectrometer to observe prompt ? rays in coincidence with recoiling fusion-evaporation residues and their subsequent decay by ? particle emission. By correlating prompt ? radiation with the characteristic ? radioactivity of Os167, it has been possible to extend the level scheme for this nucleus significantly. In particular, an extension of the yrast band and four previously unobserved bands are reported. In addition, the recoil distance Doppler-shift method was used to determine a lifetime of ?=20(4) ps for The I?=17/2+ state in Os167. Hence, the level of collectivity and magnitude of deformation of the low spin yrast band of this nucleus is established.

O'Donnell, D.; Grahn, T.; Joss, D. T.; Simpson, J.; Scholey, C.; Andgren, K.; Bianco, L.; Cederwall, B.; Cullen, D. M.; Dewald, A.; Ganio?lu, E.; Hornillos, M. B. Gómez; Greenlees, P. T.; Hadinia, B.; Iwasaki, H.; Jakobsson, U.; Jolie, J.; Jones, P.; Judson, D. S.; Julin, R.; Juutinen, S.; Ketelhut, S.; Labiche, M.; Leino, M.; Lumley, N. M.; Mason, P. J. R.; Möller, O.; Nieminen, P.; Nyman, M.; Page, R. D.; Pakarinen, J.; Paul, E. S.; Petri, M.; Petts, A.; Peura, P.; Pietralla, N.; Pissulla, Th.; Rahkila, P.; Ruotsalainen, P.; Sandzelius, M.; Sapple, P. J.; Sarén, J.; Sorri, J.; Thomson, J.; Uusitalo, J.; Watkins, H. V.

2009-06-01

316

Magnetic Manipulation of Nanorods in the Nucleus of Living Cells  

PubMed Central

The organization of chromatin in the cell nucleus is crucial for gene expression regulation. However, physically probing the nuclear interior is challenging because high forces have to be applied using minimally invasive techniques. Here, magnetic nanorods embedded in the nucleus of living cells are subjected to controlled rotational forces, producing micron-sized displacements in the nuclear interior. The resulting time-dependent rotation of the nanorods is analyzed in terms of viscoelastic parameters of the nucleus, in wild-type and Lamin A/C deficient cells. This method and analysis reveal that Lamin A/C knockout, together perhaps with other changes that result from the knockout, induce significant decreases in the nuclear viscosity and elasticity. PMID:22004741

Celedon, Alfredo; Hale, Christopher M.; Wirtz, Denis

2011-01-01

317

Three-body model calculations for 16C nucleus  

E-print Network

We apply a three-body model consisting of two valence neutrons and the core nucleus $^{14}$C in order to investigate the ground state properties and the electronic quadrupole transition of the $^{16}$C nucleus. The discretized continuum spectrum within a large box is taken into account by using a single-particle basis obtained from a Woods-Saxon potential. The calculated B(E2) value from the first 2$^+$ state to the ground state shows good agreement with the observed data with the core polarization charge which reproduces the experimental B(E2) value for $^{15}$C. We also show that the present calculation well accounts for the longitudinal momentum distribution of $^{15}$C fragment from the breakup of $^{16}$C nucleus. We point out that the dominant ($d_{5/2})^2$ configuration in the ground state of $^{16}$C plays a crucial role for these agreement.

Hagino, K

2006-01-01

318

Three-body model calculations for 16C nucleus  

E-print Network

We apply a three-body model consisting of two valence neutrons and the core nucleus $^{14}$C in order to investigate the ground state properties and the electronic quadrupole transition of the $^{16}$C nucleus. The discretized continuum spectrum within a large box is taken into account by using a single-particle basis obtained from a Woods-Saxon potential. The calculated B(E2) value from the first 2$^+$ state to the ground state shows good agreement with the observed data with the core polarization charge which reproduces the experimental B(E2) value for $^{15}$C. We also show that the present calculation well accounts for the longitudinal momentum distribution of $^{15}$C fragment from the breakup of $^{16}$C nucleus. We point out that the dominant ($d_{5/2})^2$ configuration in the ground state of $^{16}$C plays a crucial role for these agreement.

K. Hagino; H. Sagawa

2006-12-11

319

Superdeformation and hyperdeformation in the $^{108}$Cd nucleus  

E-print Network

The superdeformation and hyperdeformation in $^{108}$Cd have been studied for the first time within the framework of the fully self-consistent cranked mean field theory, namely, cranked relativistic mean field theory. The structure of observed superdeformed bands 1 and 2 have been analyzed in detail. The bumps seen in their dynamic moments of inertia are explained as arising from unpaired band crossings. This is contrary to an explanation given earlier within the framework of projected shell model. It was also concluded that this nucleus is not doubly magic SD nucleus.

A. V. Afanasjev; S. Frauendorf

2006-12-20

320

Retinal projections to the pregeniculate nucleus in the hemispherectomized monkey.  

PubMed

Intraocular injections of tritiated proline were used to test the hypothesis that unilateral removal of all visual cortical areas results in increased distribution of retinal terminals in the pregeniculate nucleus (PGN) of the thalamus in monkeys. Following hemispherectomy, retinal input to the ipsilateral PGN was reduced by an average of 18.5% when compared to its contralateral homologue, which corresponded to the reduction in nuclear volume (19.3%). Our results show that removal of cortical afferents to the external layer of the PGN does not induce invasion of retinal projections into this region of the nucleus. PMID:11044602

Théoret, H; Boire, D; Ptito, M

2000-09-15

321

Analysis of organic compounds in returned comet nucleus samples  

NASA Technical Reports Server (NTRS)

Techniques for analysis of organic compounds in returned comet nucleus samples are described. Interstellar, chondritic and transitional organic components are discussed. Appropriate sampling procedures will be essential to the success of these analyses. It will be necessary to return samples that represent all the various regimes found in the nucleus, e.g., a complete core, volatile components (deep interior), and crustal components (surface minerals, rocks, processed organics such as macromolecular carbon and polymers). Furthermore, sampling, storage, return, and distribution of samples must be done under conditions that preclude contamination of the samples by terrestrial matter.

Cronin, J. R.

1989-01-01

322

Separable Representation of Proton-Nucleus Optical Potentials  

E-print Network

Recently, a new approach for solving the three-body problem for (d,p) reactions in the Coulomb-distorted basis in momentum space was proposed. Important input quantities for such calculations are the scattering matrix elements for proton- and neutron-nucleus scattering. We present a generalization of the Ernst-Shakin-Thaler scheme in which a momentum space separable representation of proton-nucleus scattering matrix elements can be calculated in the Coulomb basis. The viability of this method is demonstrated by comparing S-matrix elements obtained for p$+^{48}$Ca and p$+^{208}$Pb for a phenomenological optical potential with corresponding coordinate space calculations.

L. Hlophe; V. Eremenko; Ch. Elster; F. M. Nunes; G. Arbanas; J. E. Escher; I. J. Thompson

2014-09-14

323

Interpretation of electron- and neutrino-nucleus scattering data  

SciTech Connect

The analysis of the sample of charged current quasi elastic events collected by the Mini-BooNE collaboration shows that the extension of the approaches successfully employed to describe electron-nucleus scattering to the case of neutrino interactions involves non trivial difficulties. In this paper it is argued that, due to flux average, the double differential neutrino-nucleus cross section does not allow for a clearcut determination of the dominant reaction mechanism. A systematic study of the large body of electron scattering data may help to identify the processes, other than single nucleon knockout, contributing to the observed neutrino cross section.

Benhar, Omar [INFN and Department of Physics, 'Sapienza' Universita di Roma, I-00192 Roma (Italy)

2011-11-23

324

Meson production in high-energy electron-nucleus scattering  

E-print Network

Experimental studies of meson production through two-photon fusion in inelastic electron-nucleus scattering is now under way. A high-energy photon radiated by the incident electron is fused with a soft photon radiated by the nucleus. The process takes place in the small-angle-Coulomb region of nuclear scattering. We expound the theory for this production process as well as its interference with coherent-radiative-meson production. In particular, we investigate the distortion of the electron wave function due to multiple-Coulomb scattering.

Göran Fäldt

2010-06-09

325

Like Attracts Like: Getting RNA Processing Together in the Nucleus  

NSDL National Science Digital Library

Structures visible within the eukaryotic nucleus have fascinated generations of biologists. Recent data show that these structures form in response to gene expression and are highly dynamic in living cells. RNA processing and assembly require many factors but the nucleus apparently lacks any active transport system to deliver these to the RNAs. Instead, processing factors move by diffusion but are concentrated by transient association with functionally related components. At sites of high activity this gives rise to visible structures, with components in dynamic equilibrium with the surrounding nucleoplasm. Processing factors are recruited from this pool by cooperative binding to RNA substrates.

Joe Lewis (The University of Edinburgh;Wellcome Trust Centre for Cell Biology); David Tollervey (The University of Edinburgh;Wellcome Trust Centre for Cell Biology)

2000-05-26

326

Sensitivity of reaction cross sections to halo nucleus density distributions  

NASA Astrophysics Data System (ADS)

In order to clear up the sensitivity of the nucleus-nucleus reaction cross sections ? R to the nuclear matter distributions in exotic halo nuclei, we have calculated the values of ? R for scattering of 6He, 11Li, and 19C nuclei on several nuclear targets at the energy of 0.8 GeV/nucleon. The calculations were performed in the "rigid target" approximation to the Glauber theory, different shapes of the nuclear density distributions in 6He, 11Li, and 19C being assumed.

Alkhazov, G. D.; Sarantsev, V. V.

2014-07-01

327

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; Glowacki, Maciej

2014-01-01

328

Role of death receptor, mitochondrial and endoplasmic reticulum pathways in different stages of degenerative human lumbar disc.  

PubMed

Intervertebral disc (IVD) cell apoptosis has been suggested to play an important role in promoting the degeneration process. It has been demonstrated that IVD cell apoptosis occurs through either death receptor, mitochondrial or endoplasmic reticulum (ER) pathway. Our study aimed to explore the relationship among these three pathways and grade of IVD degeneration (IVDD). IVDs were collected from patients with lumbar fracture, vertebral tumor, disc herniation or spondylolisthesis. IVDs were distinguished by MRI and histomorphological examination, cell apoptosis was detected by TUNEL staining. Biomarkers of these three apoptosis pathways were detected by RT-PCR and Western blot. Furthermore, the correlation between apoptosis pathways biomarkers and disc pathology were analyzed. Nucleus pulposus cell density decreased with degeneration process, and increased apoptotic ratio. ER pathway was predominant in mild stage of IVDD (GRP78, GADD153 upregulation and caspase-4 activation), death receptor pathway was predominant in mild and moderate stages (Fas, FasL up-regulation and caspase-8 activation) and mitochondrial pathway was predominant in moderate and severe stages (Bcl-2 down-regulation, Bax up-regulation, cytochrome-c accumulation in cytoplasm and caspase-9 activation). There were significant differences in the expressions of Fas, FasL, Bax, GADD153, cytochrome-c and cleaved caspase-8/9/3 between contained and non-contained discs. In conclusion, apoptosis occurs via these three apoptosis pathways together in IVDD. ER pathway plays a more critical role in the mild compared to moderate and severe stages, death receptor pathway in mild and moderate, and mitochondrial pathway in moderate and severe stages of IVDD. Disc cells apoptosis may progress rapidly after herniation, and may depend on the type of herniation. PMID:21879322

Wang, Hua; Liu, Hui; Zheng, Zhao-Min; Zhang, Kui-Bo; Wang, Tai-Ping; Sribastav, Shilabant-Sen; Liu, Wen-Sheng; Liu, Ting

2011-10-01

329

Spinal hernia tissue autofluorescence spectrum.  

PubMed

The laser intervertebral disc decompression may provide appropriate relief in properly selected patients with contained disc herniations. The present investigation aims to characterise intervertebral disc material by autofluorescence induced by laser light. Degeneration of the intervertebral disc is associated with progressive biochemical changes in disc material. Percutaneous laser disc decompression has become rather popular for the treatment of lumbar disc herniation, but there are problems in the selection of patients. For this purpose, recognition of the disc composition is necessary. We propose a new type of spectroscopic investigation. It is advantageous to the characterization of intervertebral disc material. Intervertebral disc specimens were removed during open surgery from different disc locations. Preoperative patients' MRI was evaluated using the Pfirrmann disc degeneration and Komori scale for migrating of herniated nucleus pulposus. Adjacent slices of stained disc sections were evaluated by histology/histochemistry and autofluorescence spectra. Comparison of the MRI, spectral, histological and histochemical data was performed. The MRI Komori scale correlated with the histology Boos degeneration index. In the histochemistry, collagens other than collagens I and II of the disc were distinguished with best positive correlation coefficient (0.829) and best negative one (-0.904) of proteoglycans of sequester to Boos index. A correlation of the IV Gaussian component of the hernia spectra with the Boos index was established. The Gaussian component correlation with different collagen types and proteoglycan was determined for the disc and sequester. "Autofluorescence-based diagnosis" refers to the evaluation of disc degeneration by histological and histochemical evaluation; it can provide additional data on the degeneration of an intervertebral disc. PMID:22389123

Varanius, Darius; Terbetas, Gunaras; Vaitkus, Juozas V; Vaitkuviene, Aurelija

2013-02-01

330

Final State Interactions in Neutrino-Nucleus Experiments  

NASA Astrophysics Data System (ADS)

Many neutrino-nucleus experiments need to find quasifree events in order to measure the beam energy which is an important part of oscillation measurements. Final state interactions are very important because they can mask the topology of an event. This paper reviews some of the concepts important in a good final state model and provides some detail for what is used in GENIE.

Dytman, S.

2009-09-01

331

The human granulocyte nucleus: unusual nuclear envelope and heterochromatin composition  

PubMed Central

The human blood granulocyte (neutrophil) is adapted to find and destroy infectious agents. The nucleus of the human neutrophil has a segmented appearance, consisting of a linear or branched array of three or four lobes. Adequate levels of lamin B receptor (LBR) are necessary for differentiation of the lobulated nucleus. The levels of other components of the nuclear envelope may also be important for nuclear shape determination. In the present study, immunostaining and immunoblotting procedures explored the levels of various components of the nuclear envelope and heterochromatin, comparing freshly isolated human neutrophils with granulocytic forms of HL-60 cells, a tissue culture model system. In comparison to granulocytic HL-60 cells, blood neutrophil nuclear envelopes contain low-to-negligible amounts of LBR, lamins A/C, B1 and B2, LAP2? and emerin. Surprisingly, a “mitotic” chromosome marker, H3(S10)phos, is elevated in neutrophil nuclei, compared to granulocytic HL-60 cells. Furthermore, neutrophil nuclei appear to be more fragile to methanol fixation, than observed with granulocytic HL-60 cells. Thus, the human neutrophil nucleus appears to be highly specialized, possessing a paucity of nuclear envelope-stabilizing proteins. In consequence, the neutrophil nucleus appears to be very malleable, supporting rapid migration through tight tissue spaces. PMID:18396345

Olins, Ada L.; Zwerger, Monika; Herrmann, Harald; Zentgraf, Hanswalter; Simon, Amos J.; Monestier, Marc; Olins, Donald E.

2008-01-01

332

Synaptic Arrangements in the Ventral Posterolateral Nucleus of the Squirrel  

Microsoft Academic Search

Because murine rodents have no complex synaptic arrangements in the ventral posterolateral nucleus (VPL), we sought to determine if the lack of complexity was a characteristic common to all rodents. We studied the synaptology of VPL in the fox squirrel, Sciurus niger, using electron microscopy. We found vesicle-containing dendrites and complex synaptic arrangements in the squirrel VPL. Therefore, the relative

J. Wells; B. C. Albright

1983-01-01

333

Gastric afferents to the paraventricular nucleus in the rat  

Microsoft Academic Search

Extracellular recordings were made from vasopressin (AVP) and oxytocin (OXT)-secreting cells in the paraventricular nucleus (PVN) of the hypothalamus in rats anesthetized with urethane-chloralose to determine the effects of electrical stimulation of vagal gastric nerves and gastric distension on their activity. Electrical stimulation of gastric branches of the vagus nerves inhibited 5 and excited 10 of 32 phasically firing neurosecretory

Y. Ueta; H. Kannan; H. Yamashita

1991-01-01

334

Ether Stress Stimulates Noradrenaline Release in the Hypothalamic Paraventricular Nucleus  

Microsoft Academic Search

Differential normal-pulse voltammetry was combined with treated carbon fibre electrodes for monitoring in vivo extracellular catechols synthesized by noradrenergic terminals innervating the paraventricular hypothalamic nucleus. From urethane-anaesthetized rats, pretreated with a monoamine oxidase inhibitor, pargyline, we were able to monitor a catechol signal which unequivocally corresponded to extracellular noradrenaline, and we observed that ether inhalation for 2 min induced an

Claire C. Mermet; François G. Gorton

1988-01-01

335

Synaptic Targets of Thalamic Reticular Nucleus Terminals in the Visual  

E-print Network

Synaptic Targets of Thalamic Reticular Nucleus Terminals in the Visual Thalamus of the Cat SITING Carolina 27157-1010 ABSTRACT A major inhibitory input to the dorsal thalamus arises from neurons- ined the synaptic targets of TRN terminals in the visual thalamus, including the A lamina of the dorsal

Sherman, S. Murray

336

Reversal of Experimental Parkinsonism by Lesions of the Subthalamic Nucleus  

Microsoft Academic Search

Although it is known that Parkinson's disease results from a loss of dopaminergic neurons in the substantia nigra, the resulting alterations in activity in the basal ganglia responsible for parkinsonian motor deficits are still poorly characterized. Recently, increased activity in the subthalamic nucleus has been implicated in the motor abnormalities. To test this hypothesis, the effects of lesions of the

Hagai Bergman; Thomas Wichmann; Mahlon R. Delong

1990-01-01

337

Hormonal Regulation of CREB Phosphorylation in the Anteroventral Periventricular Nucleus  

Microsoft Academic Search

The anteroventral periventricular nucleus (AVPV) is a nodal point in neural circuits regulating secretion of gonadotropin and contains sexually dimorphic populations of hormonally regu- lated dopamine-, dynorphin-, and enkephalin-containing neu- rons. Because the tyrosine hydroxylase (TH), prodynorphin (PDYN), and proenkephalin (PENK) genes contain cAMP re- sponse elements that control their expression in their promot- ers, we used histochemical methods to

Guibao Gu; Anthony A. Rojo; Michele C. Zee; Jianhua Yu; Richard B. Simerly

1996-01-01

338

Expressive language disorder after infarction of left lentiform nucleus  

Microsoft Academic Search

A 53 year old bilingual woman presented with apraxia of speech and writing in English and German after ischaemic infarction of the left posterior lentiform nucleus. Detailed language assessment revealed impairments of articulation, verbal fluency, auditory repetition, interpretation of complex semantic relationships, formulation of definitions and verbal short-term memory. The case illustrates the role of the basal ganglia in speech

J. D. Warren; H. B. Smith; L. A. Denson; H. M. Waddy

2000-01-01

339

Behavioral/Systems/Cognitive Nucleus Accumbens Dopamine/Glutamate Interaction  

E-print Network

Behavioral/Systems/Cognitive Nucleus Accumbens Dopamine/Glutamate Interaction Switches Modes are generated in a keyboard pattern by localized glutamate disruptions in NAc (via microinjection of the AMPA shell of rats. Rostral glutamate disruptions produce intense increases in eating, but more caudally

Berridge, Kent

340

Structure of levels of the {sup 160}Gd nucleus  

SciTech Connect

The scheme of excited levels of the {sup 160}Gd nucleus was refined and extended owing to the addition of the K{sub {pi}} = 2{sup -} band and the inclusion of new rotational states in other bands. Data for the respective (n, n Prime {gamma}) reaction from the literature were used. The signature splitting of K = 1 bands was found.

Grigoriev, E. P., E-mail: epgrig@bk.ru [St. Petersburg State University, Petrodvorets Branch (Russian Federation)

2012-12-15

341

The Comet Nucleus Tour (Contour); A NASA Discovery Mission  

Microsoft Academic Search

In 1997, the COmet Nucleus TOUR (CONTOUR) was selected byNASA for a new start as part of the Discovery line. In this paper,\\u000a we review the status of the mission, the mission timeline and the instruments to be flown. Detail is given of the science\\u000a goals and how they are to be accomplished.

Anita Cochran; Joseph Veverka; James Bell; Michael Belton; Johannes Benkhoff; Andrew Benkhoff; Benton Clark; Paul Feldman; Jochen Kissel; Paul Mahaffy; Michael Malin; Scott Murchie; Hasso Neimann; Tobias Owen; Mark Robinson; Gerhard Schwehm; Steve Squyres; Peter Thomas; Fred Whipple; Donald Yeomans

2000-01-01

342

Structures and functions in the crowded nucleus: new biophysical insights  

NASA Astrophysics Data System (ADS)

Concepts and methods from the physical sciences have catalysed remarkable progress in understanding the cell nucleus in recent years. To share this excitement with physicists and encourage their interest in this field, this review offers an overview of how the physics which underlies structures and functions in the nucleus is becoming more clear thanks to methods which have been developed to simulate and study macromolecules, polymers, and colloids. The environment in the nucleus is very crowded with macromolecules, making entropic (depletion) forces major determinants of interactions. Simulation and experiments are consistent with their key role in forming membraneless compartments such as nucleoli, PML and Cajal bodies, and discrete "territories" for chromosomes. The chromosomes, giant linear polyelectrolyte polymers, exist in vivo in a state like a polymer melt. Looped conformations are predicted in crowded conditions, and have been confirmed experimentally and are central to the regulation of gene expression. Polymer theory has revealed how the chromosomes are so highly compacted in the nucleus, forming a "crumpled globule" with fractal properties which avoids knots and entanglements in DNA while allowing facile accessibility for its replication and transcription. Entropic repulsion between looped polymers can explain the confinement of each chromosome to a discrete region of the nucleus. Crowding and looping are predicted to facilitate finding the specific targets of factors which modulate activities of DNA. Simulation shows that entropic effects contribute to finding and repairing potentially lethal double-strand breaks in DNA by increasing the mobility of the broken ends, favouring their juxtaposition for repair. Signaling pathways are strongly influenced by crowding, which favours a processive mode of response (consecutive reactions without releasing substrates). This new information contributes to understanding the sometimes counter-intuitive consequences.

Hancock, Ronald

2014-09-01

343

Critical evaluation of the anatomical location of the Barrington nucleus: relevance for deep brain stimulation surgery of pedunculopontine tegmental nucleus.  

PubMed

Deep brain stimulation (DBS) has become the standard surgical procedure for advanced Parkinson's disease (PD). Recently, the pedunculopontine tegmental nucleus (PPN) has emerged as a potential target for DBS in patients whose quality of life is compromised by freezing of gait and falls. To date, only a few groups have published their long-term clinical experience with PPN stimulation. Bearing in mind that the Barrington (Bar) nucleus and some adjacent nuclei (also known as the micturition centre) are close to the PPN and may be affected by DBS, the aim of the present study was to review the anatomical location of this structure in human and other species. To this end, the Bar nucleus area was analysed in mouse, monkey and human tissues, paying particular attention to the anatomical position in humans, where it has been largely overlooked. Results confirm that anatomical location renders the Bar nucleus susceptible to influence by the PPN DBS lead or to diffusion of electrical current. This may have an undesirable impact on the quality of life of patients. PMID:23732233

Blanco, Lisette; Yuste, Jose Enrique; Carrillo-de Sauvage, María Angeles; Gómez, Aurora; Fernández-Villalba, Emiliano; Avilés-Olmos, Itciar; Limousin, Patricia; Zrinzo, Ludvic; Herrero, María Trinidad

2013-09-01

344

Nucleus-to-Nucleus Gene Transfer and Protein Retargeting into a Remnant Cytoplasm of Cryptophytes and Diatoms  

E-print Network

in the periplastid com- partment (PPC), the remnant of the former red algal cytosol. In the cryptophyte and diatom endoplasmatic reticulum. In a recent report, we have shown that a nuclear encoded PPC protein of G. theta present further nucleus-encoded PPC proteins from G. theta, such as the eukaryotic translation elongation

Keeling, Patrick

345

Nucleus-to-nucleus gene transfer and protein retargeting into a remnant cytoplasm of cryptophytes and diatoms.  

PubMed

The complex plastid of the cryptophyte Guillardia theta and of the diatom Phaeodactylum tricornutum can both be traced back to an engulfed eukaryotic red alga. The eukaryotic origin of these plastids is most obvious in cryptophytes, where the organelle still possesses a remnant nucleus, the nucleomorph. The nucleomorph itself is embedded in the periplastid compartment (PPC), the remnant of the former red algal cytosol. In the cryptophyte and diatom, the complex plastid is surrounded by 4 membranes, the outer one being continuous with the host rough endoplasmatic reticulum. In a recent report, we have shown that a nuclear encoded PPC protein of G. theta expressed in P. tricornutum leads to a localization, recently described as being a "bloblike structure," which can be obtained by mutation of plastid protein-targeting sequences of the diatom itself. Here we present further nucleus-encoded PPC proteins from G. theta, such as the eukaryotic translation elongation factor-1alpha, evidence for their nucleus-to-nucleus gene transfer, and retargeting of the proteins. We also investigated the first nuclear encoded PPC-targeted protein of P. tricornutum (Hsp70) and analyzed it for in vivo localization together with the identified G. theta PPC proteins. This revealed that all localize to the bloblike structures, which we suggest is the highly reduced PPC of P. tricornutum. Furthermore, the described cryptophyte PPC proteins possibly allow the elucidation of the processes by which proteins are involved in different levels of host control over its eukaryotic organelle. PMID:16971693

Gould, Sven B; Sommer, Maik S; Kroth, Peter G; Gile, Gillian H; Keeling, Patrick J; Maier, Uwe-G

2006-12-01

346

Aggressive Angiomyxoma with Perineal Herniation  

PubMed Central

Aggressive angiomyxoma is a rare mesenchymal tumor involving the pelvic-perineal region. It occurs during the third and fourth decade of life and is predominantly seen in females. It presents clinically as a soft tissue mass in variable locations such as vulva, perianal region, buttock, or pelvis. Assessment of extent of the tumor by radiological evaluation is crucial for surgical planning; however, biopsy is essential to establish diagnosis. We present the radiological and pathological features seen in a 43-year-old female diagnosed with abdominal angiomyxoma with an unusual extension to the perineum. PMID:24987570

Narang, Seema; Kohli, Supreethi; Kumar, Vinod; Chandoke, Raj

2014-01-01

347

Indirect projections from the suprachiasmatic nucleus to the ventrolateral preoptic nucleus: a dual tract-tracing study in rat.  

PubMed

The suprachiasmatic nucleus (SCN) contains a master clock for most circadian rhythms in mammals, including daily sleep-wake cycles. The ventrolateral preoptic nucleus (VLPO) plays a key role in sleep generation and, as such, might be an important target of the SCN circadian signal. However, direct SCN projections to the VLPO are limited, suggesting that most of the SCN output to the VLPO might be conveyed indirectly. We examined this possibility by microinjecting selected known major targets of SCN efferents with biotinylated dextran-amine and/or cholera toxin B subunit, followed by analyses of retrograde labelling in the SCN and anterograde labelling in the VLPO. Retrograde labelling results confirmed that the medial preoptic area, subparaventricular zone, dorsomedial hypothalamic nucleus and posterior hypothalamic area all received projections from the SCN; these projections arose predominantly from the shell, as opposed to the core, of the SCN. Anterograde labelling results indicated that these same nuclei also projected to the VLPO, mainly its medial and ventral aspects. Comparison of the results of injections of similar sizes across different target groups indicated that the rostral part of the medial preoptic area and the caudal part of the dorsomedial hypothalamic nucleus were particularly noteworthy for the abundance of both SCN source neurons and efferent fibres and terminals in the VLPO. These results suggest that the SCN might provide indirect input to the VLPO via the medial preoptic area and the dorsomedial hypothalamic nucleus, and that these indirect neuronal pathways might play a major role in circadian control of sleep-wake cycles. PMID:12405980

Deurveilher, Samuel; Burns, Joan; Semba, Kazue

2002-10-01

348

Prior pallidotomy reduces and modifies neuronal activity in the subthalamic nucleus of Parkinson's disease patients  

E-print Network

Prior pallidotomy reduces and modifies neuronal activity in the subthalamic nucleus of Parkinson, pedunculopontine nucleus Abstract Parkinson's disease (PD) patients with prior radio-frequency lesions nigra, pars reticulata (SNr) projections to the thalamus and explain the pathophysiology of Parkinson

Friedman, Nir

349

Semiphenomenological method of analysis for intermediate-energy alpha-nucleus elastic scattering data  

SciTech Connect

We propose a semiphenomenological method of analysis for intermediate energy ..cap alpha..-nucleus elastic scattering experiments and demonstrate its usefulness by analyzing available elastic ..cap alpha..-nucleus scattering data at 1.37 GeV.

Ahmad, I.; Alvi, M.A.

1983-12-01

350

Regional Difference in Sex Steroid Action on Formation of Morphological Sex Differences in the Anteroventral Periventricular Nucleus and Principal Nucleus of the Bed Nucleus of the Stria Terminalis  

PubMed Central

Sex steroid action is critical to form sexually dimorphic nuclei, although it is not fully understood. We previously reported that masculinization of the principal nucleus of the bed nucleus of the stria terminalis (BNSTp), which is larger and has more neurons in males than in females, involves aromatized testosterone that acts via estrogen receptor-? (ER?), but not estrogen receptor-? (ER?). Here, we examined sex steroid action on the formation of the anteroventral periventricular nucleus (AVPV) that is larger and has more neurons in females. Morphometrical analysis of transgenic mice lacking aromatase, ER?, or ER? genes revealed that the volume and neuron number of the male AVPV were significantly increased by deletion of aromatase and ER? genes, but not the ER? gene. We further examined the AVPV and BNSTp of androgen receptor knockout (ARKO) mice. The volume and neuron number of the male BNSTp were smaller in ARKO mice than those in wild-type mice, while no significant effect of ARKO was found on the AVPV and female BNSTp. We also examined aromatase, ER?, and AR mRNA levels in the AVPV and BNSTp of wild-type and ARKO mice on embryonic day (ED) 18 and postnatal day (PD) 4. AR mRNA in the BNSTp and AVPV of wild-type mice was not expressed on ED18 and emerged on PD4. In the AVPV, the aromatase mRNA level was higher on ED18, although the ER? mRNA level was higher on PD4 without any effect of AR gene deletion. Aromatase and ER? mRNA levels in the male BNSTp were significantly increased on PD4 by AR gene deletion. These results suggest that estradiol signaling via ER? during the perinatal period and testosterone signaling via AR during the postnatal period are required for masculinization of the BNSTp, whereas the former is sufficient to defeminize the AVPV. PMID:25398007

Kanaya, Moeko; Tsuda, Mumeko C.; Sagoshi, Shoko; Nagata, Kazuyo; Morimoto, Chihiro; Tha Thu, Chaw Kyi; Toda, Katsumi; Kato, Shigeaki; Ogawa, Sonoko; Tsukahara, Shinji

2014-01-01

351

Distribution of proteins between nucleus and cytoplasm of amoeba proteus  

PubMed Central

By transplanting nuclei between labeled and unlabeled cells, we determined the localization of the major proteins of amebas and described certain features of their intracellular distributon. We identified approximately 130 cellular proteins by fluorography of one-dimensional polyacrylamide electrophoretic gels and found that slightly less than half of them (designated NP, for nuclear proteins) are almost exclusively nuclear. About 95 percent of the other proteins (designated CP for cytoplamsic proteins) are roughly equally concentrated in nucleus and cytoplasm, but—because the cytoplasm is 50 times larger than the nucleus—about 98 percent of each of the latter is in the cytoplasm. Of the CP, roughly 5 percent are not detectable in the nucleus. Assuming that these are restricted to the cytoplasm only because, for example, they are in structures too large to enter the nucleus and labeled CP readily exit a nucleus introduced into unlabeled cytoplasm, we conclude that the nuclear envelope does not limit the movement of any nonstructural cellular protein in either direction between the two compartments. Some NP are not found in the cytoplasm (although ostensibly synthesized there) presumably because of preferential binding within the nucleus. Almost one half of the protein mass in nuclei in vivo is CP and apparently only proteins of that group are lost from nuclei when cells are lysed. Thus, while an extracellular environment allows CP to exit isolated nuclei, the nuclear binding affinities for NP are retained. Further examination of NP distribution shows that many NP species are, in fact, detectable in the cytoplasm (although at only about 1/300 the nuclear concentration), apparently because the nuclear affinity is relatively low. These proteins are electrophoretically distinguishable from the high-affinity NP not found in the cytoplasm. New experiments show that an earlier suggestion that the nuclear transplantation operation causes an artifactual release of NP to the cytoplasm is largely incorrect. Moreover, we show that cytoplasmic “contamination” of nuclear preparations is not a factor in classifying proteins by these nuclear transplantation experiments. We speculate the no mechanism has evolved to confine most CP to the cytoplasm (where they presumably function exclusively) because the cytoplasm’s large volume ensures that CP will be abundant there. Extending Bonner’s idea of “quasi-functional nuclear binding sites” for NP, we suggest that a subset of NP usually have a low affinity for available intranuclear sites because their main function(s) occurs at other intranuclear sites to which they bind tightly only when particular metabolic conditions demand. The other NP (those completely absent from cytoplasm) presumable always are bound with high affinity at their primary functional sites. PMID:7217202

Goldstein, L; Ko, C

1981-01-01

352

Tonotopic and Somatotopic Representation in the Nucleus basalis of the Barn Owl, Tyto alba  

Microsoft Academic Search

We have investigated the somatosensory and auditory representations in the nucleus basalis of the barn owl. In pigeons and finches, the nucleus basalis contains a representation of the beak and an auditory area. In the barn owl, the nucleus basalis also contains a complete somatotopic map of the head and body (as in the budgerigar), with a tonotopically organized auditory

J. M. Wild; M. F. Kubke; C. E. Carr

2001-01-01

353

Triple F - A Comet Nucleus Sample Return Mission  

NASA Technical Reports Server (NTRS)

The Triple F (Fresh From the Fridge) mission, a Comet Nucleus Sample Return, has been proposed to ESA's Cosmic Vision program. A sample return from a comet enables us to reach the ultimate goal of cometary research. Since comets are the least processed bodies in the solar system, the proposal goes far beyond cometary science topics (like the explanation of cometary activity) and delivers invaluable information about the formation of the solar system and the interstellar molecular cloud from which it formed. The proposed mission would extract three sample cores of the upper 50 cm from three locations on a cometary nucleus and return them cooled to Earth for analysis in the laboratory. The simple mission concept with a touch-andgo sampling by a single spacecraft was proposed as an M-class mission in collaboration with the Russian space agency ROSCOSMOS.

Kueppers, Michael; Keller, H. U.; Kuehrt, E.; A'Hearn, M. F.; Altwegg, K.; Bertrand, R.; Busemann, H.; Capria, M. T.; Colangeli, L.; Davidsson, B.; Ehrenfreund, P.; Knollenberg, J.; Mottola, S.; Weiss, P.; Zolensky, M.; Akim, E.; Basilevsky, A.; Galimov, E.; Gerasimov, M.; Korablev, O.; Charnley, S.; Nittler, L. R.; Sandford, S.; Weissman, P.

2008-01-01

354

Electron Spin Resonance (ESR) Studies of Returned Comet Nucleus Samples  

NASA Technical Reports Server (NTRS)

Electron Spin Resonance (ESR) studies have been carried out on organic and inorganic free radicals generated by gamma-ray and/or UV-irradiation and trapped in ice matrices. It is suggested that the concentration of these free radicals together with their thermal stability can be used as an accurate built-in geothermometer and radiation probe for returned comet nucleus sample studies. ESR studies have also been carried out on paramagnetic (Mn(2+), Ti(3+), and Fe(3+)) and ferromagnetic (ferric oxide and metallic iron) centers known to be present in terrestrial and extraterrestrial samples. The presence or absence of these magnetic centers coupled with their characteristic ESR lineshape can be used to investigate the shock effects, quenching/cooling rate and oxidation-reduction conditions in the formation and subsequent evolution of returned comet nucleus samples.

Tsay, Fun-Dow; Kim, Soon Sam; Liang, Ranty H.

1997-01-01

355

Progressive activation of paratrigeminal nucleus during entrance to hibernation  

SciTech Connect

The paratrigeminal nucleus (Pa5) undergoes a progressive increase in its uptake of 2-({sup 14}C)deoxyglucose (2DG) relative to other brain structures during entrance to hibernation in the ground squirrel. This highly significant increase results in the Pa5 becoming the most highly labeled brain region during hibernation, even though it exhibits one of the lowest levels of 2DG uptake in the brain during the nonhibernating state. The progressive activation of the Pa5 observed during entrance is reversed during arousal from hibernation. These observations and the neuroanatomical projections of the Pa5 implicate this nucleus as playing a role in the entrance and maintenance of the hibernating state.

Kilduff, T.S.; Sharp, F.R.; Heller, H.C. (Stanford Univ., CA (USA) Univ. of California, San Francisco (USA) Veterans Administration Medical Center, San Francisco, CA (USA))

1988-07-01

356

Geometry of the nucleus: a perspective on gene expression regulation.  

PubMed

Gene expression control results from the combined interactions of the nearly hundred proteins forming the pre-initiation complex, thousands of transcription regulators, and genomic DNA. In the recent years, new technologies have revealed several key aspects of nuclear spatial organization that showed a fine interplay between the function of nuclear proteins, their 3D organization, and their dynamics. Here we review several concepts that link biochemical reactivity in the nucleus to its 3D spatial organization. We present the analogies between the emerging understanding of nuclear organization in the field of cell biology, and the more established disciplines of heterogeneous catalysis and the physics of random walks. We provide several recent examples showing how nuclear geometry affects protein reactivity in the nucleus. PMID:24981829

Woringer, Maxime; Darzacq, Xavier; Izeddin, Ignacio

2014-06-01

357

Influence of nucleus deformability on cell entry into cylindrical structures.  

PubMed

The mechanical properties of cell nuclei have been demonstrated to play a fundamental role in cell movement across extracellular networks and micro-channels. In this work, we focus on a mathematical description of a cell entering a cylindrical channel composed of extracellular matrix. An energetic approach is derived in order to obtain a necessary condition for which cells enter cylindrical structures. The nucleus of the cell is treated either (i) as an elastic membrane surrounding a liquid droplet or (ii) as an incompressible elastic material with Neo-Hookean constitutive equation. The results obtained highlight the importance of the interplay between mechanical deformability of the nucleus and the capability of the cell to establish adhesive bonds and generate active forces in the cytoskeleton due to myosin action. PMID:23838726

Giverso, C; Grillo, A; Preziosi, L

2014-06-01

358

Physical Plasticity of the Nucleus and its Manipulation  

PubMed Central

The genome is virtually identical in all cells within an organism, with epigenetic changes contributing largely to the plasticity in gene expression during both development and aging. These changes include covalent modifications of chromatin components and altered chromatin organization as well as changes in other nuclear components, such as nuclear envelope lamins. Given that DNA in each chromosome is centimeters long and dozens of chromosomes are compacted into a microns-diameter nucleus through non-trivial interactions with the bounding envelope, the polymer physics of such a structure under stress can be complex but perhaps systematic. We summarize micromanipulation methods for measuring the physical plasticity of the nucleus, with recent studies documenting the extreme flexibility of human embryonic stem cells and the rigidification in model aging of progerin-type nuclei. Lamin-A/C is a common molecular factor, and methods are presented for its knock-down and measurement. PMID:20816236

Ivanovska, Irena; Swift, Joe; Harada, Takamasa; Pajerowski, J. David; Discher, Dennis E.

2011-01-01

359

The identification of musical instruments through nucleus cochlear implants.  

PubMed

In this study, self-reported ability to recognize musical instruments was investigated by means of a questionnaire, which was sent to a group of adult Nucleus cochlear implant users and a group of normally hearing subjects. In addition, spectrograms and electrodograms were produced and analysed for samples of music played on 10 different musical instruments. Self-reported ability to recognize some instruments was poor in the group of implant users, particularly for the saxophone, tuba and clarinet. Electrodograms showed that these instruments could only be identified using distorted spectral information or reduced temporal information. Other instruments, such as the drum and piano, could be identified using temporal information. Limited spectral resolution makes the recognition of musical instruments difficult for Nucleus implant users. PMID:18792382

Grasmeder, M L; Lutman, M E

2006-09-01

360

Efficient active transport of gene nanocarriers to the cell nucleus  

PubMed Central

The intracellular transport of therapeutic gene carriers is poorly understood, limiting the rational design of efficient new vectors. We used live-cell real-time multiple particle tracking to quantify the intracellular transport of hundreds of individual nonviral DNA nanocarriers with 5-nm and 33-ms resolution. Unexpected parallels between several of nature's most efficient DNA viruses and nonviral polyethylenimine/DNA nanocomplexes were revealed to include motor protein-driven transport through the cytoplasm toward the nucleus on microtubules. Active gene carrier transport led to efficient perinuclear accumulation within minutes. The results provide direct evidence to dispute the common belief that the efficiency of nonviral gene carriers is dramatically reduced because of the need for their relatively slow random diffusion through the cell cytoplasm to the nucleus and, instead, focuses the attention of rational carrier design on overcoming barriers downstream of perinuclear accumulation. PMID:12644705

Suh, Junghae; Wirtz, Denis; Hanes, Justin

2003-01-01

361

Experiments on parity violation in the compound nucleus  

SciTech Connect

Results from experiments that measure parity-violating longitudinal asymmetries in the scattering of epithermal neutrons from compound-nuclear resonances at the Manuel Lujan Neutron Scattering Center at Los Alamos are discussed. Parity non-conserving asymmetries have been observed for many p-wave resonances in a single target. Measurements were performed on several nuclei in the mass region of A-100 and A-230. The statistical model of the compound nucleus provides a theoretical basis for extracting mean-squared matrix elements from the experimental asymmetry data, and for interpreting the mean-squared matrix elements. The constraints on the weak meson-exchange couplings calculated from the compound-nucleus asymmetry data agree qualitatively with the results from few-body and light-nuclei experiments. For all nuclei but {sup 232}Th measured asymmetries have random signs. For {sup 232}Th eight of eight measured asymmetries are positive. This phenomenon is discussed in terms or doorway models.

Bowman, J.D.

1996-09-01

362

The Midbrain Precommand Nucleus of the Mormyrid Electromotor Network  

Microsoft Academic Search

The functional role of the midbrain precommand nucleus (PCN) of the electromotor system was explored in the weakly electric mormyrid fish Gnathonemus petersii, using extracellular record- ing of field potentials, single unit activity, and microstimulation in vivo. Electromotor-related field potentials in PCN are linked in a one-to-one manner and with a fixed time relationship to the electric organ discharge (EOD)

Gerhard von der Emde; Leonel Gomez Sena; Rafaella Niso; Kirsty Grant

2000-01-01

363

Emission of charged particles from excited compound nucleus  

SciTech Connect

The formation and decay of excited compound nucleus are studied within the dinuclear system model[1]. The cross sections of complex fragment emission are calculated and compared with experimental data for the reactions {sup 3}He+{sup 108}Ag, {sup 78,82}Kr+{sup 12}C. Angular momentum dependence of cluster emission in {sup 78}Kr+{sup 12}C and {sup 40}Ca+{sup 78}Kr reactions is demonstrated.

Kalandarov, Sh. A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Nuclear Physics, Tashkent (Uzbekistan); Adamian, G. G.; Antonenko, N. V. [Joint Institute for Nuclear Research, Dubna (Russian Federation)

2010-11-24

364

The Ionization Source in the Nucleus of M84  

NASA Technical Reports Server (NTRS)

We have obtained new Hubble Space Telescope (HST) observations of M84, a nearby massive elliptical galaxy whose nucleus contains a approximately 1.5 X 10(exp 9) solar mass dark compact object, which presumably is a supermassive black hole. Our Space Telescope Imaging Spectrograph (STIS) spectrum provides the first clear detection of emission lines in the blue (e.g., [0 II] lambda 3727, HBeta and [0 III] lambda lambda4959,5007), which arise from a compact region approximately 0".28 across centered on the nucleus. Our Near Infrared Camera and MultiObject Spectrometer (NICMOS) images exhibit the best view through the prominent dust lanes evident at optical wavelengths and provide a more accurate correction for the internal extinction. The relative fluxes of the emission lines we have detected in the blue together with those detected in the wavelength range 6295 - 6867 A by Bower et al. indicate that the gas at the nucleus is photoionized by a nonstellar process, instead of hot stars. Stellar absorption features from cool stars at the nucleus are very weak. We update the spectral energy distribution of the nuclear point source and find that although it is roughly flat in most bands, the optical to UV continuum is very red, similar to the spectral energy distribution of BL Lac. Thus, the nuclear point source seen in high-resolution optical images is not a star cluster but is instead a nonstellar source. Assuming isotropic emission from this source, we estimate that the ratio of bolometric luminosity to Eddington luminosity is about 5 x 10(exp -7). However, this could be underestimated if this source is a misaligned BL Lac object, which is a possibility suggested by the spectral energy distribution and the evidence of optical variability we describe.

Bower, G. A.; Green, R. F.; Quillen, A. C.; Danks, A.; Malumuth, E. M.; Gull, T.; Woodgate, B.; Hutchings, J.; Joseph, C.; Kaiser, M. E.

2000-01-01

365

Synaptic arrangements in the ventral posterolateral nucleus of the squirrel.  

PubMed

Because murine rodents have no complex synaptic arrangements in the ventral posterolateral nucleus (VPL), we sought to determine if the lack of complexity was a characteristic common to all rodents. We studied the synaptology of VPL in the fox squirrel, Sciurus niger, using electron microscopy. We found vesicle-containing dendrites and complex synaptic arrangements in the squirrel VPL. Therefore, the relative simplicity of the rat and mouse VPL is not a general feature of the rodent somatosensory thalamus. PMID:6616170

Wells, J; Albright, B C

1983-01-01

366

The nucleus paragigantocellularis and opioid withdrawal-like behavior  

Microsoft Academic Search

Participation of the nucleus paragigantocellularis (PGi) in mediation of opioid withdrawal was examined in conscious, unrestrained, non-opioid-dependent rats, using electrical stimulation of the PGi. A characteristic series of behaviors, which resembled those seen during naloxone-precipitated withdrawal from dependence on the opioid agonist, butorphanol, was elicited during 30 min of PGi stimulation. Thus, the behavioral syndrome has been termed opioid withdrawal-like.

Robin W. Rockhold; Niansen Liu; Dominick Coleman; Stephen Commiskey; Jonathan Shook; Ing K. Ho

2000-01-01

367

The Nucleus Paragigantocellularis and Opioid Withdrawal-Like Behavior  

Microsoft Academic Search

Participation of the nucleus paragigantocellularis (PGi) in mediation of opioid withdrawal was examined in conscious, unrestrained, non-opioid-dependent rats, using electrical stimulation of the PGi. A characteristic series of behaviors, which resembled those seen during naloxone-precipitated withdrawal from dependence on the opioid agonist, butorphanol, was elicited during 30 min of PGi stimulation. Thus, the behavioral syndrome has been termed opioid withdrawal-like.

Robin W. Rockhold; Niansen Liu; Dominick Coleman; Stephen Commiskey; Jonathan Shook; Ing K. Ho

2000-01-01

368

Methods and compositions for targeting macromolecules into the nucleus  

DOEpatents

The present invention includes compositions, methods and kits for directing an agent across the nuclear membrane of a cell. The present invention includes a Karyopherin beta2 translocation motif in a polypeptide having a slightly positively charged region or a slightly hydrophobic region and one or more R/K/H-X.sub.(2-5)-P-Y motifs. The polypeptide targets the agent into the cell nucleus.

Chook, Yuh Min

2013-06-25

369

The Galactic center spur - A jet from the nucleus  

SciTech Connect

The possible detection of a 4 kpc long jetlike feature emanating from the Galactic center region is reported. The feature is some 200 pc in diameter and extends almost perpendicular to the Galactic plane and may be related to some activity in the Galactic center. The structure may possibly be a radio jet from the nucleus, or it might be a magnetic tornado produced by a twisted poloidal magnetic field between the disk and halo. 14 refs.

Sofue, Y.; Reich, W.; Reich, P. (Tokyo Univ., Mitaka (Japan); Max-Planck-Institut fuer Radioastronomie, Bonn (Germany, F.R.))

1989-06-01

370

Inclusive quasi-elastic electron-nucleus scattering  

E-print Network

This article presents a review of the field of inclusive quasi-elastic electron-nucleus scattering. It discusses the approach used to measure the data and includes a compilation of data available in numerical form. The theoretical approaches used to interpret the data are presented. A number of results obtained from the comparison between experiment and calculation are then reviewed. The analogies and differences to other fields of physics exploiting quasi-elastic scattering from composite systems are pointed out.

Omar Benhar; Donal day; Ingo Sick

2006-03-29

371

The pedunculopontine tegmental nucleus: from basic neuroscience to neurosurgical applications  

Microsoft Academic Search

One element of the reticular activating system (RAS) is the pedunculopontine nucleus (PPN), which projects to the thalamus\\u000a to trigger thalamocortical rhythms and the brainstem to modulate muscle tone and locomotion. The PPN is a posterior midbrain\\u000a site known to induce locomotion in decerebrate animals when activated at 40–60 Hz, and has become a target for DBS in disorders\\u000a involving gait

Edgar Garcia-Rill; Christen Simon; Kristen Smith; Nebosja Kezunovic; James Hyde

372

Nucleus reuniens of the thalamus contains head direction cells.  

PubMed

Discrete populations of brain cells signal heading direction, rather like a compass. These 'head direction' cells are largely confined to a closely-connected network of sites. We describe, for the first time, a population of head direction cells in nucleus reuniens of the thalamus in the freely-moving rat. This novel subcortical head direction signal potentially modulates the hippocampal CA fields directly and, thus, informs spatial processing and memory. PMID:25024427

Jankowski, Maciej M; Islam, Md Nurul; Wright, Nicholas F; Vann, Seralynne D; Erichsen, Jonathan T; Aggleton, John P; O'Mara, Shane M

2014-01-01

373

Lagged cells in alert monkey lateral geniculate nucleus.  

PubMed

Five lagged cells were recognized by extracellular recording in the lateral geniculate nucleus of an awake, behaving macaque monkey. Previous reports of lagged cells were all in the anesthetized cat. Both parvocellular and magnocellular lagged cells were observed. Response timing was distributed continuously across the population, and both sustained and transient responses were seen in the magnocellular subpopulation. Cortex thus receives signals with a wide range of timing, which can mediate direction selectivity across multiple dimensions. PMID:19000330

Saul, Alan B

2008-01-01

374

Steroid Receptor and Molecular Chaperone Encounters in the Nucleus  

NSDL National Science Digital Library

Steroid hormone receptors interact with several different molecular chaperones. DeFranco and Csermely discuss how the molecular chaperones p23 and Hsp90 may serve to regulate the activity of the ligand-bound steroid receptors within the nucleus. The authors hypothesize that these chaperone proteins may have a proactive role in promoting recycling of receptors once they have interacted with chromatin and in allowing rebinding of ligand once the receptors have been recycled.

Donald B. DeFranco (University of Pittsburgh School of Medicine;Department of Pharmacology REV); Peter Csermely (Semmelweis University;Department of Medical Chemistry REV)

2000-07-25

375

Calculation of light nucleus reaction cross sections in Geant4  

E-print Network

Total reaction cross sections of light projectile nucleus (H-2, H-3, He-3 and He-4) interactions with nuclei are calculated using Geant4 models, and compared with experimental data. It is shown that the models give various predictions at low energies, in the region of the Coulomb barrier. "Shen model" (W.-Q. Shen et al., Nucl. Phys. {\\bf A491} (1989) 130) is identified as an improvement over other models.

V. Uzhinsky

2012-09-20

376

Neutrino magnetic moment effects in neutrino nucleus reactions  

SciTech Connect

Some low energy neutrino nucleus reactions induced by neutrinos (antineutrinos) having a magnetic moment of the order of 10{sup {minus}9}{minus}10{sup {minus}10} Bohr magneton are studied. It is found that in the case of {sup 4}He, {sup 12}C, and {sup 16}O, the detection of very low energy scalar and isoscalar elastic and inelastic reactions induced by the isoscalar vector currents can provide a better limit on the neutrino magnetic moment.

Singh, S.K.; Athar, M.S. [Department of Physics, Aligarh Muslim University, Aligarh-202002 (India)] [Department of Physics, Aligarh Muslim University, Aligarh-202002 (India)

1995-10-01

377

Study of Comet Nucleus Gamma-Ray Spectrometer Penetration System  

NASA Technical Reports Server (NTRS)

A penetrator system has been suggested as an approach for making in situ measurements of the composition and physical properties of the nucleus of a comet. This study has examined in detail the feasibility of implementing the penetrator concept. The penetrator system and mission designs have been developed and iterated in sufficient detail to provide a high level of confidence that the concept can be implemented within the constraints of the Mariner Mark 2 spacecraft.

Adams, G. L.; Amundsen, R. J.; Beardsley, R. W.; Cash, R. H.; Clark, B. C.; Knight, T. C. D.; Martin, J. P.; Monti, P.; Outteridge, D. A.; Plaster, W. D.

1986-01-01

378

Gender Differences in Dopaminergic Function in Striatum and Nucleus Accumbens  

Microsoft Academic Search

In female rats the gonadal hormones estrogen and progesterone modulate dopamine (DA) activity in the striatum and nucleus accumbens. For example, there is estrous cycle-dependent variation in basal extracellular concentration of striatal DA, in amphetamine (AMPH)-stimulated DA release, and in striatal DA-mediated behaviors. Ovariectomy attenuates basal extracellular DA, AMPH-induced striatal DA release, and behaviors mediated by the striatal DA system.

Jill B Becker

1999-01-01

379

Functional organization and dynamics of the cell nucleus  

PubMed Central

The eukaryotic cell nucleus enclosed within the nuclear envelope harbors organized chromatin territories and various nuclear bodies as sub-nuclear compartments. This higher-order nuclear organization provides a unique environment to regulate the genome during replication, transcription, maintenance, and other processes. In this review, we focus on the plant four-dimensional nuclear organization, its dynamics and function in response to signals during development or stress. PMID:25161658

Guo, Tongtong; Fang, Yuda

2014-01-01

380

Micro Nucleus Detection in Human Lymphocytes Using Convolutional Neural Network  

Microsoft Academic Search

\\u000a The application of the convolution neural network for detection of the micro nucleuses in the human lymphocyte images acquired\\u000a by the image flow cytometer is considered in this paper. The existing method of detection, called IMAQ Match Pattern, is described\\u000a and its limitations concerning zoom factors are analyzed. The training algorithm of the convolution neural network and the\\u000a detection procedure

Ihor Paliy; Francesco Lamonaca; Volodymyr Turchenko; Domenico Grimaldi; Anatoly Sachenko

2010-01-01

381

An Off-centered Active Galactic Nucleus in NGC 3115  

NASA Astrophysics Data System (ADS)

NGC 3115 is an S0 galaxy that has always been considered to have a pure absorption-line spectrum. Some recent studies have detected a compact radio-emitting nucleus in this object, coinciding with the photometric center and with a candidate for the X-ray nucleus. This is evidence of the existence of a low-luminosity active galactic nucleus (AGN) in the galaxy, although no emission line has ever been observed. We report the detection of an emission-line spectrum of a type 1 AGN in NGC 3115, with an H? luminosity of L H? = (4.2 ± 0.4) × 1037 erg s–1. Our analysis revealed that this AGN is located at a projected distance of ~0.''29 ± 0.''05 (corresponding to ~14.3 ± 2.5 pc) from the stellar bulge center, which is coincident with the kinematic center of this object's stellar velocity map. The black hole corresponding to the observed off-centered AGN may form a binary system with a black hole located at the stellar bulge center. However, it is also possible that the displaced black hole is the merged remnant of the binary system coalescence, after the "kick" caused by the asymmetric emission of gravitational waves. We propose that certain features in the stellar velocity dispersion map are the result of perturbations caused by the off-centered AGN.

Menezes, R. B.; Steiner, J. E.; Ricci, T. V.

2014-11-01

382

Integration of Sensory Quanta in Cuneate Nucleus Neurons In Vivo  

PubMed Central

Discriminative touch relies on afferent information carried to the central nervous system by action potentials (spikes) in ensembles of primary afferents bundled in peripheral nerves. These sensory quanta are first processed by the cuneate nucleus before the afferent information is transmitted to brain networks serving specific perceptual and sensorimotor functions. Here we report data on the integration of primary afferent synaptic inputs obtained with in vivo whole cell patch clamp recordings from the neurons of this nucleus. We find that the synaptic integration in individual cuneate neurons is dominated by 4–8 primary afferent inputs with large synaptic weights. In a simulation we show that the arrangement with a low number of primary afferent inputs can maximize transfer over the cuneate nucleus of information encoded in the spatiotemporal patterns of spikes generated when a human fingertip contact objects. Hence, the observed distributions of synaptic weights support high fidelity transfer of signals from ensembles of tactile afferents. Various anatomical estimates suggest that a cuneate neuron may receive hundreds of primary afferents rather than 4–8. Therefore, we discuss the possibility that adaptation of synaptic weight distribution, possibly involving silent synapses, may function to maximize information transfer in somatosensory pathways. PMID:23409195

Bengtsson, Fredrik; Brasselet, Romain; Johansson, Roland S.; Arleo, Angelo; Jorntell, Henrik

2013-01-01

383

Neuronal code of spatial visual information in the caudate nucleus.  

PubMed

Earlier reports described huge overlapping visual receptive fields and the absence of retinotopic organization in the dorsolateral, caudal part of the caudate nucleus. In the present study we suggest a possible alternative mechanism for the coding of spatial visual information. Extracellular microelectrode recordings were carried out in halothane-anesthetized, immobilized, artificially ventilated cats. In order to investigate the responsiveness of the single neurons to visual information arriving from different sites of the receptive field, we divided the visual fields to 20 parts of equal size and stimulated the individual parts one-by-one. We found that each single visual caudate nucleus (CN) neuron can carry information about stimulus locations throughout the whole physically approachable visual field of the investigated eye. A large majority (85%) of these neurons exhibited significantly different responses to stimuli appearing in different regions of their huge receptive field. Thus these neurons appear to have the ability to provide information on the site of the stimulus via their discharge rate. The huge receptive fields in combination with the spatial selectivity suggest that these caudate nucleus neurons may serve as panoramic localizers. On the population level, the sites of maximal responsiveness of the visual neurons are distributed over the whole extent of the receptive fields. We argue that groups of these panoramic localizer neurons with different locations of maximal stimulus preference should have the ability to accurately code the locations of visual stimuli. We propose this distributed population code of visual information as an alternative information processing mechanism. PMID:21376107

Gombköto, P; Rokszin, A; Berényi, A; Braunitzer, G; Utassy, G; Benedek, G; Nagy, A

2011-05-19

384

An off-centered active galactic nucleus in NGC 3115  

E-print Network

NGC 3115 is an S0 galaxy that has always been considered to have a pure absorption-line spectrum. Some recent studies have detected a compact radio-emitting nucleus in this object, coinciding with the photometric center and with a candidate for the X-ray nucleus. This is evidence of the existence of a low-luminosity active galactic nucleus (AGN) in the galaxy, although no emission line has ever been observed. We report the detection of an emission-line spectrum of a type 1 AGN in NGC 3115, with an H$\\alpha$ luminosity of $L_{H\\alpha} = (4.2 \\pm 0.4) \\times 10^{37}$ erg s$^{-1}$. Our analysis revealed that this AGN is located at a projected distance of $\\sim 0.29" \\pm 0.05"$ (corresponding to $\\sim 14.3 \\pm 2.5$ pc) from the stellar bulge center, which is coincident with the kinematic center of this object's stellar velocity map. The black hole corresponding to the observed off-centered AGN may form a binary system with a black hole located at the stellar bulge center. However, it is also possible that the dis...

Menezes, R B; Ricci, T V

2014-01-01

385

The MicroRNA Biology of the Mammalian Nucleus  

PubMed Central

MicroRNAs (miRNAs) are a class of genome-encoded small RNAs that are primarily considered to be post-transcriptional negative regulators of gene expression acting in the cytoplasm. Over a decade of research has focused on this canonical paradigm of miRNA function, with many success stories. Indeed, miRNAs have been identified that act as master regulators of a myriad of cellular processes, and many miRNAs are promising therapeutic targets or disease biomarkers. However, it is becoming increasingly apparent that the canonical view of miRNA function is incomplete. Several lines of evidence now point to additional functions for miRNAs in the nucleus of the mammalian cell. The majority of cellular miRNAs are present in both the nucleus and the cytoplasm, and certain miRNAs show specific nuclear enrichment. Additionally, some miRNAs colocalize with sub-nuclear structures such as the nucleolus and chromatin. Multiple components of the miRNA processing machinery are present in the nuclear compartment and are shuttled back and forth across the nuclear envelope. In the nucleus, miRNAs act to regulate the stability of nuclear transcripts, induce epigenetic alterations that either silence or activate transcription at specific gene promoters, and modulate cotranscriptional alternative splicing events. Nuclear miRNA-directed gene regulation constitutes a departure from the prevailing view of miRNA function and as such, warrants detailed further investigation. PMID:25137140

Roberts, Thomas C

2014-01-01

386

Experimental studies of pion-nucleus interactions at intermediate energies  

SciTech Connect

This report summarizes the work on experimental research in intermediate energy nuclear physics carried out at New Mexico State University in 1991 under a great from the US Department of Energy. Most of these studies have involved investigations of various pion-nucleus interactions. The work has been carried out both with the LAMPF accelerator at the Los Alamos National Laboratory and with the cyclotron at the Paul Scherrer Institute (PSI) near Zurich, Switzerland. Part of the experimental work involves measurements of new data on double-charge-exchange scattering, using facilities at LAMPF which we helped modify, and on pion absorption, using a new detector system at PSI that covers nearly the full solid-angle region which we helped construct. Other work involved preparation for future experiments using polarized nuclear targets and a new high-resolution spectrometer system for detecting {pi}{sup 0} mesons. We also presented several proposals for works to be done in future years, involving studies related to pi-mesonic atoms, fundamental pion-nucleon interactions, studies of the difference between charged and neutral pion interactions with the nucleon, studies of the isospin structure of pion-nucleus interactions, and pion scattering from polarized {sup 3}He targets. This work is aimed at improving our understanding of the pion-nucleon interaction, of the pion-nucleus interaction mechanism, and of nuclear structure.

Not Available

1991-12-31

387

Proteomic characterization of protein phosphatase complexes of the mammalian nucleus.  

PubMed

Our knowledge of the serine/threonine protein phosphatases of the mammalian nucleus is limited compared with their cytosolic counterparts. Microcystin-Sepharose chromatography and mass spectrometry were utilized to affinity purify and identify protein phosphatase-associated proteins from isolated rat liver nuclei. Far Western analysis with labeled protein phosphatase 1 (PP1) showed that many more PP1 binding proteins exist in the nucleus than were previously demonstrated. Mass spectrometry confirmed the presence in the nucleus of the mammalian PP1 isoforms alpha1, alpha2, beta, and gamma1, plus the Aalpha and several of the B and B' subunits that are complexed to PP2A. Other proteins enriched on the microcystin matrix include the spliceosomal proteins known as the U2 snRNPs SAP145 and SAP155 and the U5 snRNPs p116 and p200, myosin heavy chain, and a nuclear PP1 myosin-targeting subunit related to M110. The putative RNA binding protein ZAP was also established as a nuclear PP1 binding protein using the criteria of co-purification with PP1 on microcystin-Sepharose, co-immunoprecipation, binding PP1 in an overlay assay, and presence of a putative PP1 binding site (KKRVRWAD). These results further support a key role for protein phosphatases in several nuclear functions, including the regulation of pre-mRNA splicing. PMID:14724321

Tran, Hue T; Ulke, Annegret; Morrice, Nick; Johannes, Christine J; Moorhead, Greg B G

2004-03-01

388

Cytoarchitecture and efferent projections of the nucleus incertus of the rat.  

PubMed

The nucleus incertus is located caudal to the dorsal raphe and medial to the dorsal tegmentum. It is composed of a pars compacta and a pars dissipata and contains acetylcholinesterase, glutamic acid decarboxylase, and cholecystokinin-positive somata. In the present study, anterograde tracer injections in the nucleus incertus resulted in terminal-like labeling in the perirhinal cortex and the dorsal endopyriform nucleus, the hippocampus, the medial septum diagonal band complex, lateral and triangular septum medial amygdala, the intralaminar thalamic nuclei, and the lateral habenula. The hypothalamus contained dense plexuses of fibers in the medial forebrain bundle that spread in nearly all nuclei. Labeling in the suprachiasmatic nucleus filled specifically the ventral half. In the midbrain, labeled fibers were observed in the interpeduncular nuclei, ventral tegmental area, periaqueductal gray, superior colliculus, pericentral inferior colliculus, pretectal area, the raphe nuclei, and the nucleus reticularis pontis oralis. Retrograde tracer injections were made in areas reached by anterogradely labeled fibers including the medial prefrontal cortex, hippocampus, amygdala, habenula, nucleus reuniens, superior colliculus, periaqueductal gray, and interpeduncular nuclei. All these injections gave rise to retrograde labeling in the nucleus incertus but not in the dorsal tegmental nucleus. These data led us to conclude that there is a system of ascending projections arising from the nucleus incertus to the median raphe, mammillary complex, hypothalamus, lateral habenula, nucleus reuniens, amygdala, entorhinal cortex, medial septum, and hippocampus. Many of the targets of the nucleus incertus were involved in arousal mechanisms including the synchronization and desynchronization of the theta rhythm. PMID:12866129

Olucha-Bordonau, Francisco E; Teruel, Vicent; Barcia-González, Jorge; Ruiz-Torner, Amparo; Valverde-Navarro, Alfonso A; Martínez-Soriano, Francisco

2003-09-01

389

Differential Control of Sex Differences in Estrogen Receptor ? in the Bed Nucleus of the Stria Terminalis and Anteroventral Periventricular Nucleus  

PubMed Central

The principal nucleus of the bed nucleus of the stria terminalis (BNSTp) and anteroventral periventricular nucleus of the hypothalamus (AVPV) are sexually dimorphic, hormone-sensitive forebrain regions. Here we report a profound sex difference in estrogen receptor-? (ER?) immunoreactivity (IR) in the BNSTp, with robust ER? IR in females and the near absence of labeling in males. This sex difference is due to the suppression of ER? IR by testicular hormones in adulthood: it was not present at birth and was not altered by neonatal treatment of females with estradiol; gonadectomy of adult males increased ER? IR to that of females, whereas gonadectomy of adult females had no effect. Treating gonadally intact males with an aromatase inhibitor partially feminized ER? IR in the BNSTp, suggesting that testicular suppression required aromatization. By contrast, in AVPV we found a modest sex difference in ER? IR that was relatively insensitive to steroid manipulations in adulthood. ER? IR in AVPV was, however, masculinized in females treated with estradiol at birth, suggesting that the sex difference is due to organizational effects of estrogens. The difference in ER? IR in the BNSTp of males and females appears to be at least in part due to greater expression of mRNA of the ER? gene (Esr1) in females. The sex difference in message is smaller than the difference in immunoreactivity, however, suggesting that posttranscriptional mechanisms also contribute to the pronounced suppression of ER? IR and presumably to functions mediated by ER? in the male BNSTp. PMID:24025225

Varnum, M. M.; Krentzel, A. A.; Krug, S.; Forger, N. G.

2013-01-01

390

Forebrain afferents to the rat dorsal raphe nucleus demonstrated by retrograde and anterograde tracing methods.  

PubMed

The dorsal raphe nucleus through its extensive efferents has been implicated in a great variety of physiological and behavioural functions. However, little is know about its afferents. Therefore, to identify the systems likely to influence the activity of serotonergic neurons of the dorsal raphe nucleus, we re-examined the forebrain afferents to the dorsal raphe nucleus using cholera toxin b subunit and Phaseolus vulgaris-leucoagglutinin as retrograde or anterograde tracers. With small cholera toxin b subunit injection sites, we further determined the specific afferents to the ventral and dorsal parts of the central dorsal raphe nucleus, the rostral dorsal raphe nucleus and the lateral wings. In agreement with previous studies, we observed a large number of retrogradely-labelled cells in the lateral habenula following injections in all subdivisions of the dorsal raphe nucleus. In addition, depending on the subdivision of the dorsal raphe nucleus injected, we observed a small to large number of retrogradely-labelled cells in the orbital, cingulate, infralimbic, dorsal peduncular, and insular cortice, a moderate or substantial number in the ventral pallidum and a small to substantial number in the claustrum. In addition, we observed a substantial to large number of cells in the medial and lateral preoptic areas and the medial preoptic nucleus after cholera toxin b subunit injections in the dorsal raphe nucleus excepting for those located in the ventral part of the central dorsal raphe nucleus, after which we found a moderate number of retrogradely-labelled cells. Following cholera toxin b subunit injections in the dorsal part of the central dorsal raphe nucleus, a large number of retrogradely-labelled cells was seen in the lateral, ventral and medial parts of the bed nucleus of the stria terminalis whereas only a small to moderate number was visualized after injections in the other dorsal raphe nucleus subdivisions. In addition, respectively, a substantial and a moderate number of retrogradely-labelled cells was distributed in the zona incerta and the subincertal nucleus following all tracer injections in the dorsal raphe nucleus. A large number of retrogradely-labelled cells was also visualized in the lateral, dorsal and posterior hypothalamic areas and the perifornical nucleus after cholera toxin b subunit injections in the dorsal part of the central raphe nucleus and to a lesser extent following injections in the other subdivisions. We further observed a substantial to large number of retrogradely-labelled cells in the tuber cinereum and the medial tuberal nucleus following cholera toxin b subunit injections in the dorsal part of the central dorsal raphe nucleus or the lateral wings and a small to moderate number after injections in the two other dorsal raphe nucleus subdivisions. A moderate or substantial number of labelled cells was also seen in the ventromedial hypothalamic area and the arcuate nucleus following cholera toxin injections in the dorsal part of the central dorsal raphe nucleus and the lateral wings and an occasional or small number with injection sites located in the other subdivisions. Finally, we observed, respectively, a moderate and a substantial number of retrogradely-labelled cells in the central nucleus of the amygdala following tracer injections in the ventral or dorsal parts of the central dorsal raphe nucleus and a small number after injections in the other subnuclei. In agreement with these retrograde data, we visualized anterogradely-labelled fibres heterogeneously distributed in the dorsal raphe nucleus following Phaseolus vulgaris-leucoagglutinin injections in the lateral orbital or infralimbic cortice, the lateral preoptic area, the perifornical nucleus, the lateral or posterior hypothalamic areas, the zona incerta, the subincertal nucleus or the medial tuberal nucleus. (ABSTRACT TRUNCATED) PMID:9466453

Peyron, C; Petit, J M; Rampon, C; Jouvet, M; Luppi, P H

1998-01-01

391

Contralateral Effects and Binaural Interactions in Dorsal Cochlear Nucleus  

PubMed Central

The dorsal cochlear nucleus (DCN) receives afferent input from the auditory nerve and is thus usually thought of as a monaural nucleus, but it also receives inputs from the contralateral cochlear nucleus as well as descending projections from binaural nuclei. Evidence suggests that some of these commissural and efferent projections are excitatory, whereas others are inhibitory. The goals of this study were to investigate the nature and effects of these inputs in the DCN by measuring DCN principal cell (type IV unit) responses to a variety of contralateral monaural and binaural stimuli. As expected, the results of contralateral stimulation demonstrate a mixture of excitatory and inhibitory influences, although inhibitory effects predominate. Most type IV units are weakly, if at all, inhibited by tones but are strongly inhibited by broadband noise (BBN). The inhibition evoked by BBN is also low threshold and short latency. This inhibition is abolished and excitation is revealed when strychnine, a glycine-receptor antagonist, is applied to the DCN; application of bicuculline, a GABAA-receptor antagonist, has similar effects but does not block the onset of inhibition. Manipulations of discrete fiber bundles suggest that the inhibitory, but not excitatory, inputs to DCN principal cells enter the DCN via its output pathway, and that the short latency inhibition is carried by commissural axons. Consistent with their respective monaural effects, responses to binaural tones as a function of interaural level difference are essentially the same as responses to ipsilateral tones, whereas binaural BBN responses decrease with increasing contralateral level. In comparison to monaural responses, binaural responses to virtual space stimuli show enhanced sensitivity to the elevation of a sound source in ipsilateral space but reduced sensitivity in contralateral space. These results show that the contralateral inputs to the DCN are functionally relevant in natural listening conditions, and that one role of these inputs is to enhance DCN processing of spectral sound localization cues produced by the pinna. PMID:16075189

2005-01-01

392

Identification of a Signaling Network in Lateral Nucleus of Amygdala Important for Inhibiting Memory Specifically Related to Learned Fear  

Microsoft Academic Search

We identified the Grp gene, encoding gastrin-releasing peptide, as being highly expressed both in the lateral nucleus of the amygdala, the nucleus where associations for Pavlovian learned fear are formed, and in the regions that convey fearful auditory information to the lateral nucleus. Moreover, we found that GRP receptor (GRPR) is expressed in GABAergic interneurons of the lateral nucleus. GRP

Gleb P. Shumyatsky; Evgeny Tsvetkov; Gaël Malleret; Svetlana Vronskaya; Michael Hatton; Lori Hampton; James F. Battey; Catherine Dulac; Eric R. Kandel; Vadim Y. Bolshakov

2002-01-01

393

Nuclear medium effects in ?(?¯)-nucleus deep inelastic scattering  

NASA Astrophysics Data System (ADS)

We study nuclear medium effects in the weak structure functions F2(x,Q2) and F3(x,Q2) in the deep inelastic neutrino and antineutrino induced reactions in nuclei. We use a theoretical model for the nuclear spectral functions which incorporates the conventional nuclear effects, such as Fermi motion, binding, and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. The calculations have been performed using relativistic nuclear spectral functions. Our results are compared with the experimental data of the NuTeV and the CERN Dortmund Heidelberg Saclay Warsaw (CDHSW) collaborations.

Haider, H.; Simo, I. Ruiz; Athar, M. Sajjad; Vacas, M. J. Vicente

2011-11-01

394

Hyperfine Structure Constant of the Neutron Halo Nucleus Be+11  

NASA Astrophysics Data System (ADS)

The hyperfine splittings of ground state Be+11 have been measured precisely by laser-microwave double resonance spectroscopy for trapped and laser cooled beryllium ions. The ions were produced at relativistic energies and subsequently slowed down and trapped at mK temperatures. The magnetic hyperfine structure constant of Be+11 was determined to be A11=-2677.302 988(72) MHz from the measurements of the mF-mF'=0-0 field independent transition. This measurement provides essential data for the study of the distribution of the halo neutron in the single neutron halo nucleus Be11 through the Bohr-Weisskopf effect.

Takamine, A.; Wada, M.; Okada, K.; Sonoda, T.; Schury, P.; Nakamura, T.; Kanai, Y.; Kubo, T.; Katayama, I.; Ohtani, S.; Wollnik, H.; Schuessler, H. A.

2014-04-01

395

A Numerical Modeling Approach to Cometary Nucleus Surface Roughness Determination  

NASA Astrophysics Data System (ADS)

Activity of cometary nuclei is closely linked with thermophysical processes. Main catalyst to activity is the diurnal temperature wave induced by solar heating. Highly resolved comet nucleus geometric models are used to model temperatures with flat surfacial facets taken from shape modeling approaches [1, 3]. Recent analyses of Groussin et al. [4] and Davidsson et al. [2] compared thermal inertia and surface temperatures of Tempel 1 and Hartley 2 synthetic models to those derived from spectral images. They outlined that applying beaming factors and radiative self-heating is not sufficient to understand the thermal behaviour of the nucleus surface. Regions with large incidence angles (e.g. at the morning terminator) distinctively deviate from predicted temperatures. One of the main contributions to this deviation is the effect of surface roughness with scals that are considerably smaller than the model facets. Combined with a relatively low thermal inertia, temperatures cover a wide range of values even at closest neighbourhood to each other. The radiative measurement for a distant observer unveils a smearing effect that indicates higher temperatures compared to average. The authors follow two numerical approaches to model small-scale surface roughness: (A) by using randomly generated fractal surfaces and (B) by downscaling groups of facets originating from larger shape models of Tempel 1. We apply a model that accounts for both radiative heat exchange for all facets and shadowing effects due to incoming solar radiation. These values are calculated in a thermal model. The revealed temperatures are analyzed with respect to average large-scale surface temperatures. Hence, they are compared to deviating temperatures that are measured by a distant observer that is unable to resolve sub-structure surface patterns. A parametric study varying thermal inertia and the degree of surface roughness then outlines a bandwidth of feasible surface structures and relates them to derived temperature by remote sensing. A surface roughness parameter is introduced that takes into account these effects while keeping numerical nucleus models simple. The results outline that a surface roughness parameter can be a way to model small, unresolved morphological nucleus features in order to better understand the thermal behaviour and to predict related ffects, e.g. the onset of activity. It has to be noted, however, that other effects might have a considerable influence on thermal surface diurnal waves, as well as seasonal effects and orbital changes.

Höfner, S.; Vincent, J.-B.; Sierks, H.; Blum, J.

2013-09-01

396

NMR frequency and magnetic dipole moment of (3)He nucleus.  

PubMed

We present new gas-phase NMR spectra which relate the resonance frequency of (3)He nucleus to the resonance frequency of the proton in tetramethylsilane (TMS). We discuss the dependence of (3)He resonance frequency on the density of the solvent gas, and we consider in detail the absolute shielding scales of both nuclei. Finally, we analyse the accuracy of the results, using the relationship between the resonance frequencies, absolute shielding constants and magnetic dipole moments of (1)H and (3)He nuclei. PMID:18442939

Jackowski, Karol; Jaszu?ski, Micha?; Kamie?ski, Bohdan; Wilczek, Marcin

2008-07-01

397

Magnetic Moment of Proton Drip-Line Nucleus (9)C  

NASA Technical Reports Server (NTRS)

The magnetic moment of the proton drip-line nucleus C-9(I(sup (pi)) = 3/2, T(sub 1/2) = 126 ms) has been measured for the first time, using the beta-NMR detection technique with polarized radioactive beams. The measure value for the magnetic moment is 1mu(C-9)! = 1.3914 +/- 0.0005 (mu)N. The deduced spin expectation value of 1.44 is unusually larger than any other ones of even-odd nuclei.

Matsuta, K.; Fukuda, M.; Tanigaki, M.; Minamisono, T.; Nojiri, Y.; Mihara, M.; Onishi, T.; Yamaguchi, T.; Harada, A.; Sasaki, M.

1994-01-01

398

Active galactic nucleus feedback in clusters of galaxies  

PubMed Central

Observations made during the last ten years with the Chandra X-ray Observatory have shed much light on the cooling gas in the centers of clusters of galaxies and the role of active galactic nucleus (AGN) heating. Cooling of the hot intracluster medium in cluster centers can feed the supermassive black holes found in the nuclei of the dominant cluster galaxies leading to AGN outbursts which can reheat the gas, suppressing cooling and large amounts of star formation. AGN heating can come in the form of shocks, buoyantly rising bubbles that have been inflated by radio lobes, and the dissipation of sound waves. PMID:20351250

Blanton, Elizabeth L.; Clarke, T. E.; Sarazin, Craig L.; Randall, Scott W.; McNamara, Brian R.

2010-01-01

399

Michel decay spectrum for a muon bound to a nucleus  

E-print Network

The spectrum of electrons from muons decaying in an atomic bound state is significantly modified by their interaction with the nucleus. Somewhat unexpectedly, its first measurement, at the Canadian laboratory TRIUMF, differed from basic theory. We show, using a combination of techniques developed in atomic, nuclear, and high-energy physics, that radiative corrections eliminate the discrepancy. In addition to solving that outstanding problem, our more precise predictions are potentially useful for interpreting future high-statistics muon experiments that aim to search for exotic interactions at $10^{-16}$ sensitivity.

Andrzej Czarnecki; Matthew Dowling; Xavier Garcia i Tormo; William J. Marciano; Robert Szafron

2014-06-13

400

Michel decay spectrum for a muon bound to a nucleus  

NASA Astrophysics Data System (ADS)

The spectrum of electrons from muons decaying in an atomic bound state is significantly modified by their interaction with the nucleus. Somewhat unexpectedly, its first measurement, at the Canadian laboratory TRIUMF, differed from basic theory. We show, using a combination of techniques developed in atomic, nuclear, and high-energy physics, that radiative corrections eliminate the discrepancy. In addition to solving that outstanding problem, our more precise predictions are potentially useful for interpreting future high-statistics muon experiments that aim to search for exotic interactions at 10-16 sensitivity.

Czarnecki, Andrzej; Dowling, Matthew; Garcia i Tormo, Xavier; Marciano, William J.; Szafron, Robert

2014-11-01

401

Nucleus reuniens of the thalamus contains head direction cells  

PubMed Central

Discrete populations of brain cells signal heading direction, rather like a compass. These ‘head direction’ cells are largely confined to a closely-connected network of sites. We describe, for the first time, a population of head direction cells in nucleus reuniens of the thalamus in the freely-moving rat. This novel subcortical head direction signal potentially modulates the hippocampal CA fields directly and, thus, informs spatial processing and memory. DOI: http://dx.doi.org/10.7554/eLife.03075.001 PMID:25024427

Jankowski, Maciej M; Islam, Md Nurul; Wright, Nicholas F; Vann, Seralynne D; Erichsen, Jonathan T; Aggleton, John P; O'Mara, Shane M

2014-01-01

402

Nuclear medium effects in $?(\\bar?)$-nucleus deep inelastic scattering  

E-print Network

We study the nuclear medium effects in the weak structure functions $F_2(x,Q^2)$ and $F_3(x,Q^2)$ in the deep inelastic neutrino/antineutrino reactions in nuclei. We use a theoretical model for the nuclear spectral functions which incorporates the conventional nuclear effects, such as Fermi motion, binding and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. The calculations have been performed using relativistic nuclear spectral functions which include nucleon correlations. Our results are compared with the experimental data of NuTeV and CDHSW.

H. Haider; I. Ruiz Simo; M. Sajjad Athar; M. J. Vicente Vacas

2011-08-16

403

[Hematoma of the head of the caudate nucleus].  

PubMed

We studied five patients with cerebral hemorrhage limited to the head of the caudate nucleus. This rare localization represents 11% of central nuclei hemorrhages. This entity has various clinical expressions; some are similar to a subarachnoid hemorrhage, others show the same manifestations associated with hemiparesis and neuropsychological findings, while still in others, the neuropsychological syndrome with speech, behaviour or memory disturbances predominates. Recovery depends on the patient's previous clinical status and on the presence of associated lesions at the time of hemorrhage. Typical warning signs, like headache, are often absent in the elderly and debilitated. Meningismus is explained by the intraventricular extension of the hemorrhage. Motor deficit, usually moderate, is probably due to impairment of the anterior portion of the posterior arm of the internal capsule. Destruction of the head of the left caudate nucleus, which is part of the circuit causing "subcortical aphasias", is responsible for non specific speech disturbances, that are however remarkably rich in semantic paraphasias. These dysfunctions could be caused by a "cortical diaschisis" as suggested by SPECT analysis. Memory dysfunction as a result of caudate lesion is questioned. However confusion and behavioural disturbances, like preservations, transitory mutism and self neglect, seem characteristic. As shown by cerebral blood flow (CBF) studies, these disturbances might represent a frontal dysfunction caused by the interruption of the dorso-latero-prefrontal and orbito-frontal circuits. When the hemorrhage extends beyond the head of the caudate nucleus, behavioural changes occur due to the involvement of neighbouring structures such as the thalamus, internal capsule, temporal lobe and nucleus accumbens. Caudate hemorrhages occur mostly in the elderly, often with long-standing arterial hypertension causing lesions of the lenticulo-striate arteries. Severe stenosis or complete occlusion of the middle cerebral artery with a fragile anastomotic circuit or angiopathies in younger individuals (particularly Asiatics: moyamoya disease) are less frequent, but they should be considered and investigated by arteriography. Vascular malformations are a rare cause and a relationship with amyloid angiopathy can only be suspected. PMID:2291035

Pedrazzi, P; Bogousslavsky, J; Regli, F

1990-01-01

404

Research Program towards Observation of Neutrino-Nucleus Coherent Scattering  

E-print Network

The article describes the research program pursued by the TEXONO Collaboration towards an experiment to observe coherent scattering between neutrinos and the nucleus at the power reactor. The motivations of studying this process are surveyed. In particular, a threshold of 100-200 eV has been achieved with an ultra-low-energy germanium detector prototype. This detection capability at low energy can also be adapted to conduct searches of Cold Dark Matter in the low-mass region as well as to enhance the sensitivities in the study of neutrino magnetic moments.

Henry T. Wong

2005-11-01

405

The Ventral Premammillary Nucleus Links Metabolic Cues and Reproduction  

PubMed Central

The amount of body fat and the energy balance are important factors that influence the timing of puberty and the normal reproductive function. Leptin is a key hormone that conveys to the central nervous system information about the individual energy reserve and modulates the hypothalamus–pituitary–gonad (HPG) axis. Recent findings suggest that the ventral premammillary nucleus (PMV) mediates the effects of leptin as a permissive factor for the onset of puberty and the coordinated secretion of luteinizing hormone during conditions of negative energy balance. In this review, we will summarize the existing literature about the potential role played by PMV neurons in the regulation of the HPG axis. PMID:22649378

Donato, Jose; Elias, Carol Fuzeti

2011-01-01

406

Lepton event rates in neutrino-nucleus DIS  

SciTech Connect

In this work we have studied the nuclear effect in F{sub 2}{sup A}(x) and F{sub 3}{sup A}(x) weak structure functions and calculated {nu}-nucleus cross section using them by taking into account Fermi motion, binding energy, pion and rho meson cloud contributions and shadowing and anti-shadowing effects. The numerical calculations have been performed in a local density approximation using relativistic nuclear spectral functions which include nucleon correlations for nuclear matter. The results have been compared with the experimental results of NuTeV and CDHSW collaborations.

Haider, H.; Athar, M. Sajjad [Department of Physics, Aligarh Muslim University, Aligarh-202 002 (India); Simo, I. Ruiz; Vicente Vacas, M. J. [Departamento de Fisica Teorica and IFIC, Centro Mixto Universidad de Valencia-CSIC, Institutos de Investigacion de Paterna, E-46071 Valencia (Spain)

2011-10-06

407

Extraction of probability of compound-nucleus formation  

NASA Astrophysics Data System (ADS)

We propose an empirical barrier distribution for a unified description of heavy-ion fusion and quasi-elastic scattering based on the Skyrme energy-density functional approach. The capture (fusion) cross sections and the quasi-elastic scattering cross sections of a large number of reactions can be well reproduced. Based on these systematic studies and the HIVAP calculations for the survival probability, the probability P of the compound-nucleus formation is extracted from the measured evaporation residue cross sections for “cold” and “hot” fusion reactions.

Wang, N.; Liu, M.

2010-03-01

408

Hyperfine structure constant of the neutron halo nucleus (11)Be(+).  

PubMed

The hyperfine splittings of ground state Be+11 have been measured precisely by laser-microwave double resonance spectroscopy for trapped and laser cooled beryllium ions. The ions were produced at relativistic energies and subsequently slowed down and trapped at mK temperatures. The magnetic hyperfine structure constant of Be+11 was determined to be A11=-2677.302?988(72)??MHz from the measurements of the mF-mF'=0-0 field independent transition. This measurement provides essential data for the study of the distribution of the halo neutron in the single neutron halo nucleus Be11 through the Bohr-Weisskopf effect. PMID:24815642

Takamine, A; Wada, M; Okada, K; Sonoda, T; Schury, P; Nakamura, T; Kanai, Y; Kubo, T; Katayama, I; Ohtani, S; Wollnik, H; Schuessler, H A

2014-04-25

409

Investigation of a central nucleus of the amygdala/dorsal raphe nucleus serotonergic circuit implicated in fear-potentiated startle  

PubMed Central

Serotonergic systems are thought to play an important role in control of motor activity and emotional states. We used a fear-potentiated startle paradigm to investigate the effects of a motor-eliciting stimulus in the presence or absence of induction of an acute fear state on serotonergic neurons in the dorsal raphe nucleus (DR) and cells in subdivisions of the central amygdaloid nucleus (CE), a structure that plays an important role in fear responses, using induction of the protein product of the immediate-early gene, c-fos. In Experiment 1 we investigated the effects of fear conditioning training, by training rats to associate a light cue (conditioned stimulus, CS; 1000 lx, 2 sec) with foot shock (0.5 s, 0.5 mA) in a single session. In Experiment 2 rats were given two training sessions identical to Experiment 1 on days 1 and 2, then tested in one of four conditions on day 3: 1) placement in the training context without exposure to either the CS or acoustic startle (AS), 2) exposure to 10 trials of the 2 s CS, 3) exposure to 40 110 dB AS trials, or 4) exposure to 40 110 dB AS trials with 10 of the trials preceded by and co-terminating with the CS. All treatments were conducted during a 20 min session. Fear conditioning training, by itself, increased c-Fos expression in multiple subdivisions of the CE and throughout the DR. In contrast, fear-potentiated startle selectively increased c-Fos expression in the medial subdivision of the CE and in serotonergic neurons in the dorsal part of the dorsal raphe nucleus (DRD). These data are consistent with previous studies demonstrating that fear-related stimuli selectively activate DRD serotonergic neurons. Further studies of this mesolimbocortical serotonergic system could have important implications for understanding mechanisms underlying vulnerability to stress-related psychiatric disorders, including anxiety and affective disorders. PMID:21277950

Spannuth, Benjamin M.; Hale, Matthew W.; Evans, Andrew K.; Lukkes, Jodi L.; Campeau, Serge; Lowry, Christopher A.

2011-01-01

410

Partition of cross sections in asymmetric nucleus-nucleus reactions and the origin of fast alpha particles  

SciTech Connect

To investigate the mechanism of asymmetric nucleus-nucleus reactions from the Coulomb barrier to intermediate energies the /sup 14/N + /sup 159/Tb reaction was studied at five bombarding energies between 8 and 23 MeV/u via particle-particle correlations (at selected energies) and particle KX-ray coincidences to identify the specific reaction channels. With the KX-ray method partial cross sections for projectile-like fragments (PLF) as a function of the atomic number (Z/sub res/) of the residual nucleus can be determined. The charge balance yields the ''missing charge'' dZ = Z/sub proj/ + Z/sub targ/ - Z/sub PLF/ - Z/sub TLF/ that indicates whether, in addition to the PLF, other charged particles are emitted. A large fraction of the inclusive cross sections is found to originate from such channels with two or more fragments in the exit channel, and this fraction increases as the PLF is further removed in mass from the incident projectile, and with increasing bombarding energy. From the particle-particle correlation studies it is found that sequential decays of PLF's are dominant. ''Non-sequential'' processes, if present, are associated with inelastic reactions involving excitations of both projectile and target. The bulk of the large alpha-particle cross section at small angles is found to be associated with channels in which, in addition to the alpha particle, only nucleons and other alpha particles are emitted. From ..gamma..-ray multiplicity measurements and from the broad distribution of the strength with Z/sub res/ it is concluded that these alpha particles originate from inelastic (damped) processes. 27 refs., 10 figs.

Siemssen, R.H.

1985-01-01

411

Minor spliceosome components are predominantly localized in the nucleus  

PubMed Central

Recently, it has been reported that there is a differential subcellular distribution of components of the minor U12-dependent and major U2-dependent spliceosome, and further that the minor spliceosome functions in the cytoplasm. To study the subcellular localization of the snRNA components of both the major and minor spliceosomes, we performed in situ hybridizations with mouse tissues and human cells. In both cases, all spliceosomal snRNAs were nearly exclusively detected in the nucleus, and the minor U11 and U12 snRNAs were further shown to colocalize with U4 and U2, respectively, in human cells. Additionally, we examined the distribution of several spliceosomal snRNAs and proteins in nuclear and cytoplasmic fractions isolated from human cells. These studies revealed an identical subcellular distribution of components of both the U12- and U2-dependent spliceosomes. Thus, our data, combined with several earlier publications, establish that, like the major spliceosome, components of the U12-dependent spliceosome are localized predominantly in the nucleus. PMID:18559850

Pessa, Heli K. J.; Will, Cindy L.; Meng, Xiaojuan; Schneider, Claudia; Watkins, Nicholas J.; Perala, Nina; Nymark, Mariann; Turunen, Janne J.; Luhrmann, Reinhard; Frilander, Mikko J.

2008-01-01

412

Minor spliceosome components are predominantly localized in the nucleus.  

PubMed

Recently, it has been reported that there is a differential subcellular distribution of components of the minor U12-dependent and major U2-dependent spliceosome, and further that the minor spliceosome functions in the cytoplasm. To study the subcellular localization of the snRNA components of both the major and minor spliceosomes, we performed in situ hybridizations with mouse tissues and human cells. In both cases, all spliceosomal snRNAs were nearly exclusively detected in the nucleus, and the minor U11 and U12 snRNAs were further shown to colocalize with U4 and U2, respectively, in human cells. Additionally, we examined the distribution of several spliceosomal snRNAs and proteins in nuclear and cytoplasmic fractions isolated from human cells. These studies revealed an identical subcellular distribution of components of both the U12- and U2-dependent spliceosomes. Thus, our data, combined with several earlier publications, establish that, like the major spliceosome, components of the U12-dependent spliceosome are localized predominantly in the nucleus. PMID:18559850

Pessa, Heli K J; Will, Cindy L; Meng, Xiaojuan; Schneider, Claudia; Watkins, Nicholas J; Perälä, Nina; Nymark, Mariann; Turunen, Janne J; Lührmann, Reinhard; Frilander, Mikko J

2008-06-24

413

Visualization of fast calcium oscillations in the parafascicular nucleus  

PubMed Central

The parafascicular nucleus (Pf) is an ascending target of the pedunculopontine nucleus (PPN) and is part of the “non-specific” intralaminar thalamus. The PPN, part of the reticular activating system, is mainly involved in waking and rapid eye movement (REM) sleep. Gamma oscillations are evident in all Pf neurons and mediated by high threshold voltage-dependent N- and P/Q-type calcium channels. We tested the hypothesis that high-speed calcium imaging would reveal calcium mediated oscillations in synchrony with patch clamp recorded oscillations during depolarizing current ramps. Patch-clamped 9 to 19 day old rat Pf neurons (n = 148, dye filled n = 61, control n = 87) were filled with Fura 2, Bis Fura, or Oregon Green BAPTA-1. Calcium transients were generated during depolarizing current ramps and visualized with a high-speed, wide-field fluorescence imaging system. Cells manifested calcium transients with oscillations in both somatic and proximal dendrite fluorescence recordings. Fluorescent calcium transients were blocked with the nonspecific calcium channel blocker, cadmium, or the combination of ?- Agatoxin-IVA (AgA), a specific P/Q-type calcium channel blocker and ?-conotoxin-GVIA (CgTx), a specific N-type calcium channel blocker. We developed a viable methodology for studying high-speed oscillations without the use of multi-photon imaging systems. PMID:23588378

Hyde, James; Kezunovic, Nebojsa; Urbano, Francisco J.; Garcia-Rill, Edgar

2013-01-01

414

Cajal's contribution to the knowledge of the neuronal cell nucleus.  

PubMed

In 1906, the Spanish neurobiologist Santiago Ramón y Cajal was awarded the Nobel Prize in Physiology or Medicine in recognition of his work on the structure of neurons and their connections. Cajal is commonly regarded as the father of modern neuroscience. What is less well known is that Cajal also had a great interest in intracellular neuronal structures and developed the reduced silver nitrate method for the study of neurofibrils (neurofilaments) and nuclear subcompartments. It was in 1903 that Cajal discovered the "accessory body" ("Cajal body") and seven years later, published an article on the organization of the cell nucleus in mammalian neurons that represents a masterpiece of nuclear structure at the light microscopy level. In addition to the accessory body, it includes the analysis of several nuclear components currently recognized as fibrillar centers of the nucleolus, nuclear speckles of splicing factors, transcription foci, nuclear matrix, and the double nuclear membrane. The aim of this article is to revisit Cajal's contributions to the knowledge of the neuronal nucleus in light of our current understanding of nuclear structure and function. PMID:19404660

Lafarga, Miguel; Casafont, Iñigo; Bengoechea, Rocio; Tapia, Olga; Berciano, Maria T

2009-08-01

415

Signaling from the secretory granule to the nucleus.  

PubMed

Neurons and endocrine cells use a complex array of signaling molecules to communicate with each other and with various targets. The majority of these signaling molecules are stored in specialized organelles awaiting release on demand: 40-60 nm vesicles carry conventional or small molecule neurotransmitters, and 200-400 nm granules contain bioactive peptides. The supply of small molecule neurotransmitters is tightly regulated by local feedback of synthetic rates and transport processes at sites of release. The larger granules that contain bioactive peptides present the secretory cell with special challenges, as the peptide precursors are inserted into the lumen of the secretory pathway in the cell soma and undergo biosynthetic processing while being transported to distant sites for eventual secretion. One solution to this dilemma in information handling has been to employ proteolytic cleavage of secretory granule membrane proteins to produce cytosolic fragments that can signal to the nucleus, affecting gene expression. The use of regulated intramembrane proteolysis to signal from secretory granules to the nucleus is compared to its much better understood role in relaying information from the endoplasmic reticulum by SREBP and ATF6 and from the plasma membrane by cadherins, Notch and ErbB4. PMID:22681236

Rajagopal, Chitra; Mains, Richard E; Eipper, Betty A

2012-01-01

416

Coulomb Excitation of the N = 50 nucleus {sup 80}Zn  

SciTech Connect

Neutron rich Zinc isotopes, including the N = 50 nucleus {sup 80}Zn, were produced and post-accelerated at the Radioactive Ion Beam (RIB) facility REX-ISOLDE (CERN). Low-energy Coulomb excitation was induced on these isotopes after post-acceleration, yielding B(E2) strengths to the first excited 2{sup +} states. For the first time, an excited state in {sup 80}Zn was observed and the 2{sub 1}{sup +} state in {sup 78}Zn was established. The measured B(E2,2{sub 1}{sup +}{yields}0{sub 1}{sup +}) values are compared to two sets of large scale shell model calculations. Both calculations reproduce the observed B(E2) systematics for the full Zinc isotopic chain. The results for N = 50 isotones indicate a good N = 50 shell closure and a strong Z = 28 proton core polarization. The new results serve as benchmarks to establish theoretical models, predicting the nuclear properties of the doubly magic nucleus {sup 78}Ni.

Van de Walle, J.; Cocolios, T. E.; Huyse, M.; Ivanov, O.; Mayet, P.; Raabe, R.; Sawicka, M.; Stefanescu, I.; Duppen, P. van [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, Leuven (Belgium); Aksouh, F. [Instituut voor Kern- en Stralingsfysica, K.U. Leuven, Leuven, Belgium CEA Saclay, DAPNIA/SPhN, Gif-sur-Yvette (France); Ames, F.; Habs, D.; Lutter, R. [Ludwig-Maximilians-Universitaet, Muenchen (Germany); Behrens, T.; Gernhauser, R.; Kroell, T.; Kruecken, R. [Physik Department E12, Technische Universitaet Muenchen, Garching (Germany); Bildstein, V. [Physik Department E12, Technische Universitaet Muenchen, Garching, GermanyMax-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Blazhev, A.; Eberth, J. [Institut fuer Kernphysik, Universitaet Koeln, Koeln (Germany)] (and others)

2008-05-12

417

Coulomb excitation of the proton-dripline nucleus Na20  

NASA Astrophysics Data System (ADS)

The low-energy structure of the proton dripline nucleus Na20 has been studied using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. A 1.7-MeV/nucleon Na20 beam of ~5×106 ions/s was Coulomb excited by a 0.5-mg/cm2natTi target. Scattered beam and target particles were detected by the BAMBINO segmented Si detector while ? rays were detected by two TIGRESS HPGe clover detectors set perpendicular to the beam axis. Coulomb excitation from the 2+ ground state to the first excited 3+ and 4+ states was observed, and B(?L) values were determined using the 2+?0+ de-excitation in Ti48 as a reference. The resulting B(?L)? values are B(E2;3+?2+)=55±6e2fm4 (17.0±1.9 W.u.), B(E2;4+?2+)=35.7±5.7e2fm4 (11.1±1.8 W.u.), and B(M1;4+?3+)=0.154±0.030?N2 (0.086±0.017 W.u.). These measurements provide the first experimental determination of B(?L) values for this proton dripline nucleus of astrophysical interest.

Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C. J.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.;