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Sample records for adjacent level degeneration

  1. Adjacent-level arthroplasty following cervical fusion.

    PubMed

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

    2017-02-01

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

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

    PubMed Central

    Repantis, Thomas; Zacharatos, Spyros; Zafiropoulos, Andreas

    2009-01-01

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

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

    PubMed

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

    2015-08-01

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

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

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-12-14

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

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

    PubMed Central

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

    2017-01-01

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

  8. Adjacency graphs and long-range interactions of atoms in quasi-degenerate states: applied graph theory

    NASA Astrophysics Data System (ADS)

    Adhikari, C. M.; Debierre, V.; Jentschura, U. D.

    2017-01-01

    We analyze, in general terms, the evolution of energy levels in quantum mechanics, as a function of a coupling parameter, and demonstrate the possibility of level crossings in systems described by irreducible matrices. In long-range interactions, the coupling parameter is the interatomic distance. We demonstrate the utility of adjacency matrices and adjacency graphs in the analysis of "hidden" symmetries of a problem; these allow us to break reducible matrices into irreducible subcomponents. A possible breakdown of the no-crossing theorem for higher-dimensional irreducible matrices is indicated, and an application to the 2 S-2 S interaction in hydrogen is briefly described. The analysis of interatomic interactions in this system is important for further progress on optical measurements of the 2 S hyperfine splitting.

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

    PubMed

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

    2016-04-01

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

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

    PubMed Central

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

    2013-01-01

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

  11. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2017-03-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index ( I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  12. Assessment of heavy metal levels in surface sediments of estuaries and adjacent coastal areas in China

    NASA Astrophysics Data System (ADS)

    Liu, Xianbin; Li, Deliang; Song, Guisheng

    2016-05-01

    This article investigates the variations of contamination levels of heavy metals such as copper, lead, chromium, cadmium, zinc, arsenic, and mercury over time in surface sediments of the Changjiang River Estuary (CRE), Yellow River Estuary (YRE), Pearl River Estuary (PRE), and their adjacent coastal areas in China. The contamination factor (CF), pollution load index (PLI), and geoaccumulation index (I geo) are used to evaluate the quality of the surface sediments in the study areas. The results showed that the CRE, YRE, and their adjacent coastal areas were at a low risk of contamination in terms of heavy metals, while the PRE and its adjacent coastal area were at a moderate level. By comparison, the concentrations of heavy metals in the surface sediments of the YRE and its adjacent coastal area were relatively lower than those in the CRE, PRE, and their adjacent coastal areas.

  13. Decreased Transcription Factor Binding Levels Nearby Primate Pseudogenes Suggest Regulatory Degeneration

    PubMed Central

    Douglas, Gavin M.; Wilson, Michael D.; Moses, Alan M.

    2016-01-01

    Characteristics of pseudogene degeneration at the coding level are well-known, such as a shift toward neutral rates of nonsynonymous substitutions and gain of frameshift mutations. In contrast, degeneration of pseudogene transcriptional regulation is not well understood. Here, we test two predictions of regulatory degeneration along a pseudogenized lineage: 1) Decreased transcription factor (TF) binding and 2) accelerated evolution in putative cis-regulatory regions. We find evidence for decreased TF binding levels nearby two primate pseudogenes compared with functional liver genes. However, the majority of TF-bound sequences nearby pseudogenes do not show evidence for lineage-specific accelerated rates of evolution. We conclude that decreases in TF binding level could be a marker for regulatory degeneration, while sequence degeneration in primate cis-regulatory modules may be obscured by background rates of TF binding site turnover. PMID:26882985

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

    PubMed Central

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

    2015-01-01

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

  15. Percutaneous ethanol embolization and cement augmentation of aggressive vertebral hemangiomas at two adjacent vertebral levels.

    PubMed

    Cianfoni, Alessandro; Massari, Francesco; Dani, Genta; Lena, Jonathan R; Rumboldt, Zoran; Vandergrift, William A; Bonaldi, Giuseppe

    2014-10-01

    This report describes a case of successful percutaneous direct-puncture ethanol embolization, followed by vertebroplasty, of an aggressive vertebral hemangioma (VH) involving two adjacent thoracic vertebral levels. In this case, the 78-year-old male patient presented with a 6-month history of progressive paraparesis due to spinal cord compression by a T8-T9 VH with an extensive epidural component. Follow-up demonstrated epidural component shrinkage with complete regression of symptoms at 3 months. This case suggests that exclusive percutaneous treatment may be considered for symptomatic VH even when two adjacent vertebral levels are affected.

  16. Tabu search approaches for the multi-level warehouse layout problem with adjacency constraints

    NASA Astrophysics Data System (ADS)

    Zhang, G. Q.; Lai, K. K.

    2010-08-01

    A new multi-level warehouse layout problem, the multi-level warehouse layout problem with adjacency constraints (MLWLPAC), is investigated. The same item type is required to be located in adjacent cells, and horizontal and vertical unit travel costs are product dependent. An integer programming model is proposed to formulate the problem, which is NP hard. Along with a cube-per-order index policy based heuristic, the standard tabu search (TS), greedy TS, and dynamic neighbourhood based TS are presented to solve the problem. The computational results show that the proposed approaches can reduce the transportation cost significantly.

  17. Biomechanics of Disc Degeneration

    PubMed Central

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

    2012-01-01

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

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

    PubMed Central

    Lee, Young-Seok; Park, Seung-Won

    2015-01-01

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

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

    PubMed Central

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

    2007-01-01

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

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

    PubMed

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

    2007-01-01

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

  1. Correlation of sea level falls interpreted from atoll stratigraphy with turbidites in adjacent basins

    SciTech Connect

    Lincoln, J.M. )

    1990-05-01

    Past sea levels can be derived from any atoll subsurface sediments deposited at or near sea level by determining the ages of deposition and correcting the present depths to the sediments for subsidence of the underlying edifice since the times of deposition. A sea level curve constructed by this method consists of discontinuous segments, each corresponding to a period of rising relative sea level and deposition of a discrete sedimentary package. Discontinuities in the sea level curve derived by this method correspond to relative sea level falls and stratigraphic hiatuses in the atoll subsurface. During intervals of relative sea level fall an atoll emerges to become a high limestone island. Sea level may fluctuate several times during a period of atoll emergence to become a high limestone island. Sea level may fluctuate several times during a period of atoll emergence without depositing sediments on top of the atoll. Furthermore, subaerial erosion may remove a substantial part of the depositional record of previous sea level fluctuations. For these reasons the authors must look to the adjacent basins to complement the incomplete record of sea level change recorded beneath atolls. During lowstands of sea level, faunas originally deposited near sea level on an atoll may be eroded and redeposited as turbidites in deep adjacent basins. Three such turbidites penetrated during deep-sea drilling at Sites 462 and 315 in the central Pacific correlate well with a late Tertiary sea level curve based on biostratigraphic ages and {sup 87}Sr/{sup 86}Sr chronostratigraphy for core from Enewetak Atoll in the northern Marshall Islands. Further drilling of the archipelagic aprons adjacent to atolls will improve the sea level history that may be inferred from atoll stratigraphy.

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

    PubMed Central

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

    2014-01-01

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

  3. MRI quantification of human spine cartilage endplate geometry: Comparison with age, degeneration, level, and disc geometry.

    PubMed

    DeLucca, John F; Peloquin, John M; Smith, Lachlan J; Wright, Alexander C; Vresilovic, Edward J; Elliott, Dawn M

    2016-08-01

    Geometry is an important indicator of disc mechanical function and degeneration. While the geometry and associated degenerative changes in the nucleus pulposus and the annulus fibrosus are well-defined, the geometry of the cartilage endplate (CEP) and its relationship to disc degeneration are unknown. The objectives of this study were to quantify CEP geometry in three dimensions using an MRI FLASH imaging sequence and evaluate relationships between CEP geometry and age, degeneration, spinal level, and overall disc geometry. To do so, we assessed the MRI-based measurements for accuracy and repeatability. Next, we measured CEP geometry across a larger sample set and correlated CEP geometric parameters to age, disc degeneration, level, and disc geometry. The MRI-based measures resulted in thicknesses (0.3-1 mm) that are comparable to prior measurements of CEP thickness. CEP thickness was greatest at the anterior/posterior (A/P) margins and smallest in the center. The CEP A/P thickness, axial area, and lateral width decreased with age but were not related to disc degeneration. Age-related, but not degeneration-related, changes in geometry suggest that the CEP may not follow the progression of disc degeneration. Ultimately, if the CEP undergoes significant geometric changes with aging and if these can be related to low back pain, a clinically feasible translation of the FLASH MRI-based measurement of CEP geometry presented in this study may prove a useful diagnostic tool. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1410-1417, 2016.

  4. The Highwire Ubiquitin Ligase Promotes Axonal Degeneration by Tuning Levels of Nmnat Protein

    PubMed Central

    Xiong, Xin; Hao, Yan; Sun, Kan; Li, Jiaxing; Li, Xia; Mishra, Bibhudatta; Soppina, Pushpanjali; Wu, Chunlai; Hume, Richard I.; Collins, Catherine A.

    2012-01-01

    Axonal degeneration is a hallmark of many neuropathies, neurodegenerative diseases, and injuries. Here, using a Drosophila injury model, we have identified a highly conserved E3 ubiquitin ligase, Highwire (Hiw), as an important regulator of axonal and synaptic degeneration. Mutations in hiw strongly inhibit Wallerian degeneration in multiple neuron types and developmental stages. This new phenotype is mediated by a new downstream target of Hiw: the NAD+ biosynthetic enzyme nicotinamide mononucleotide adenyltransferase (Nmnat), which acts in parallel to a previously known target of Hiw, the Wallenda dileucine zipper kinase (Wnd/DLK) MAPKKK. Hiw promotes a rapid disappearance of Nmnat protein in the distal stump after injury. An increased level of Nmnat protein in hiw mutants is both required and sufficient to inhibit degeneration. Ectopically expressed mouse Nmnat2 is also subject to regulation by Hiw in distal axons and synapses. These findings implicate an important role for endogenous Nmnat and its regulation, via a conserved mechanism, in the initiation of axonal degeneration. Through independent regulation of Wnd/DLK, whose function is required for proximal axons to regenerate, Hiw plays a central role in coordinating both regenerative and degenerative responses to axonal injury. PMID:23226106

  5. Measurement of outdoor noise levels adjacent to K-25 facility, ORGDP

    SciTech Connect

    Rodman, C.W.

    1981-08-27

    In order to obtain baseline data on environmental sound for a report on the expected environmental effects of constructing an incinerator adjacent to the ORGDP, an abbreviated measurement program was carried out. Ten measurement locations were selected for the measurements, six being representative of the ORGDP fenceline, and four representative of the surrounding area. Measurements consisted of short-term octave-band measurements and one-half hour A-weighted exceedance levels. It had been previously determined that the influence of the K-25 plant on the noise environment tends to stabilize the minimum sound level in such a way that nighttime measurements would not be needed.

  6. Spontaneous Regression of Herniated Lumbar Disc with New Disc Protrusion in the Adjacent Level

    PubMed Central

    Gürcan, Serkan

    2016-01-01

    Spontaneous regression of herniated lumbar discs was reported occasionally. The mechanisms proposed for regression of disc herniation are still incomplete. This paper describes and discusses a case of spontaneous regression of herniated lumbar discs with a new disc protrusion in the adjacent level. A 41-year-old man was admitted with radiating pain and numbness in the left lower extremity with a left posterolateral disc extrusion at L5-S1 level. He was admitted to hospital with low back pain due to disc herniation caudally immigrating at L4-5 level three years ago. He refused the surgical intervention that was offered and was treated conservatively at that time. He had no neurological deficit and a history of spontaneous regression of the extruded lumbar disc; so, a conservative therapy, including bed rest, physical therapy, nonsteroidal anti-inflammatory drugs, and analgesics, was advised. In conclusion, herniated lumbar disc fragments may regress spontaneously. Reports are prone to advise conservative treatment for extruded or sequestrated lumbar disc herniations. However, these patients should be followed up closely; new herniation at adjacent/different level may occur. Furthermore, it is important to know which herniated disk should be removed and which should be treated conservatively, because disc herniation may cause serious complications as muscle weakness and cauda equine syndrome. PMID:27429818

  7. Lamb shift of non-degenerate energy level systems placed between two infinite parallel conducting plates

    NASA Astrophysics Data System (ADS)

    Billaud, B.; Truong, T.-T.

    2013-01-01

    In this paper, the Lamb shift in systems with non-degenerate energy levels, put in the electromagnetic environment provided by two infinite parallel conducting plates, is analyzed. An explicit formula giving the relative Lamb shift (as compared to the standard one in a vacuum) is derived for spherical semiconductor quantum dots (QDs), via a careful mathematical treatment of divergences in the calculations using the theory of distributions. This result settles a controversy between two different formulas existing in the current literature. Its sensitive dependence on the plates separation may be viewed as an indirect manifestation of the Lamb shift and may be used for the fine tuning of the QD non-degenerate energy spectrum in some experimental contexts.

  8. Correlation of cytokine levels and microglial cell infiltration during retinal degeneration in RCS rats.

    PubMed

    Liu, Yong; Yang, Xuesen; Utheim, Tor Paaaske; Guo, Chenying; Xiao, Mingchun; Liu, Yan; Yin, Zhengqin; Ma, Jie

    2013-01-01

    Microglial cells, which are immunocompetent cells, are involved in all diseases of the central nervous system. During their activation in various diseases, a variety of soluble factors are released. In the present study, the correlation between cytokine levels and microglial cell migration in the course of retinal degeneration of Royal College of Surgeons (RCS) rats was evaluated. MFG-E8 and CD11b were used to confirm the microglial cells. In the retina of RCS rats, the mRNA expression of seven genes (MFG-E8 and its integrins αυ and ß5, CD11b and the cytokines TNF-α, IL-1ß, and MCP-1) formed almost similar bimodal peak distributions, which were centred at P7 and P45 to P60. In contrast, in rdy rats, which comprised the control group, a unimodal peak distribution centred at P14 was observed. The gene expression accompanied the activation and migration of microglial cells from the inner to the outer layer of the retina during the process of degeneration. Principal component analysis and discriminant function analysis revealed that the expression of these seven genes, especially TNF-α and CD11b, positively correlated with retinal degeneration and microglial activity during retinal degeneration in RCS rats, but not in the control rats. Furthermore, linear regression analysis demonstrated a significant correlation between the expression of these genes and the activation of microglial cells in the dystrophic retina. Our findings suggest that the suppression of microglial cells and the blockade of their cytotoxic effects may constitute a novel therapeutic strategy for treating photoreceptor death in various retinal disorders.

  9. MSC response to pH levels found in degenerating intervertebral discs

    SciTech Connect

    Wuertz, Karin Godburn, Karolyn; Iatridis, James C.

    2009-02-20

    Painful degenerative disc disease is a major health problem and for successful tissue regeneration, MSCs must endure and thrive in a harsh disc microenvironment that includes matrix acidity as a critical factor. MSCs were isolated from bone marrow of Sprague-Dawley rats from two different age groups (<1 month, n = 6 and 4-5 months, n = 6) and cultured under four different pH conditions representative of the healthy, mildly or severely degenerated intervertebral disc (pH 7.4, 7.1, 6.8, and 6.5) for 5 days. Acidity caused an inhibition of aggrecan, collagen-1, and TIMP-3 expression, as well as a decrease in proliferation and viability and was associated with a change in cell morphology. Ageing had generally minor effects but young MSCs maintained greater mRNA expression levels. As acidic pH levels are typical of increasingly degenerated discs, our findings demonstrate the importance of early interventions and predifferentiation when planning to use MSCs for reparative treatments.

  10. StabilimaxNZ® versus simulated fusion: evaluation of adjacent-level effects

    PubMed Central

    Henderson, Gweneth; James, Yue; Timm, Jens Peter

    2007-01-01

    Rationale behind motion preservation devices is to eliminate the accelerated adjacent-level effects (ALE) associated with spinal fusion. We evaluated multidirectional flexibilities and ALEs of StabilimaxNZ® and simulated fusion applied to a decompressed spine. StabilimaxNZ® was applied at L4–L5 after creating a decompression (laminectomy of L4 plus bilateral medial facetectomy at L4–L5). Multidirectional Flexibility and Hybrid tests were performed on six fresh cadaveric human specimens (T12–S1). Decompression increased average flexion–extension rotation to 124.0% of the intact. StabilimaxNZ® and simulated fusion decreased the motion to 62.4 and 23.8% of intact, respectively. In lateral bending, corresponding increase was 121.6% and decreases were 57.5 and 11.9%. In torsion, corresponding increase was 132.7%, and decreases were 36.3% for fusion, and none for StabilimaxNZ® ALE was defined as percentage increase over the intact. The ALE at L3–4 was 15.3% for StabilimaxNZ® versus 33.4% for fusion, while at L5–S1 the ALE were 5.0% vs. 11.3%, respectively. In lateral bending, the corresponding ALE values were 3.0% vs. 19.1%, and 11.3% vs. 35.8%, respectively. In torsion, the corresponding values were 3.7% vs. 20.6%, and 4.0% vs. 33.5%, respectively. In conclusion, this in vitro study using Flexibility and Hybrid test methods showed that StabilimaxNZ® stabilized the decompressed spinal level effectively in sagittal and frontal planes, while allowing a good portion of the normal rotation, and concurrently it did not produce significant ALEs as compared to the fusion. However, it did not stabilize the decompressed specimen in torsion. PMID:17924151

  11. Root length and alveolar bone level of impacted canines and adjacent teeth after orthodontic traction: a long-term evaluation

    PubMed Central

    da SILVA, Aldir Cordeiro; CAPISTRANO, Anderson; de ALMEIDA-PEDRIN, Renata Rodrigues; CARDOSO, Maurício de Almeida; CONTI, Ana Cláudia de Castro Ferreira; CAPELOZZA, Leopoldino

    2017-01-01

    Abstract Objective The aim of this retrospective study was to evaluate the long-term effects of orthodontic traction on root length and alveolar bone level in impacted canines and adjacent teeth. Material and Methods Sample consisted of 16 patients (nine males and seven females), mean initial age 11 years and 8 months presenting with unilaterally maxillary impacted canines, palatally displaced, treated with the same surgical and orthodontic approach. Teeth from the impacted-canine side were assigned as Group I (GI), and contralateral teeth as control, Group II (GII). The mean age of patients at the end of orthodontic treatment was 14 years and 2 months and the mean post-treatment time was 5 years and 11 months. Both contralateral erupted maxillary canines and adjacent teeth served as control. Root length and alveolar bone level (buccal and palatal) were evaluated on cone-beam computed tomography (CBCT) images. The comparison of root length and alveolar bone level changes between groups were assessed by applying paired t-test, at a significance level of 5% (p<0.05). Results There were no statistically significant differences in root length and buccal and palatal bone levels of canines and adjacent teeth among groups. Conclusions Impacted canine treatment by closed-eruption technique associated with canine crown perforation, has a minimal effect on root length and buccal and palatal alveolar bone level in both canine and adjacent teeth, demonstrating that this treatment protocol has a good long-term prognosis. PMID:28198979

  12. Association between Blood Lead Levels and Age-Related Macular Degeneration

    PubMed Central

    Hwang, Ho Sik; Lee, Seung Bum; Jee, Donghyun

    2015-01-01

    Purpose To investigate the association between blood lead levels and prevalence of age-related macular degeneration (AMD). Methods A nationwide population-based cross-sectional study included 4,933 subjects aged over 40 years who participated in the 2008–2012 Korean National Health and Nutrition Examination Survey, and for whom fundus photographs were available. All participants underwent a standardized interview, evaluation of blood lead concentration, and a comprehensive ophthalmic examination. Digital fundus photographs (45°) were taken of both eyes under physiological mydriasis. All fundus photographs were graded using an international classification and grading system. Results Mean blood lead levels were 3.15 μg/dL in men and 2.27 μg/dL in women (P < 0.001). After adjusting for potential confounders including age, gender, smoking status, total cholesterol levels, triglyceride levels, heart problems and strokes, the adjusted odds ratio (OR) in women for any AMD was 1.86 (95% Confidence Interval [CI], 1.03–3.36) and for early AMD was 1.92 (95% CI, 1.06–3.48), for those in the highest quintile of lead level compared with the lowest quintile. In men, however, blood lead level was not significantly associated with AMD. Conclusions Blood lead levels were higher in men, but were only associated with AMD in women. Increased levels of blood lead may be involved in the pathogenesis of AMD development in women. PMID:26252225

  13. Adjacent-Level Hypermobility and Instrumented-Level Fatigue Loosening With Titanium and PEEK Rods for a Pedicle Screw System: An In Vitro Study.

    PubMed

    Agarwal, Aakas; Ingels, Marcel; Kodigudla, Manoj; Momeni, Narjes; Goel, Vijay; Agarwal, Anand K

    2016-05-01

    Adjacent-level disease is a common iatrogenic complication seen among patients undergoing spinal fusion for low back pain. This is attributed to the postsurgical differences in stiffness between the spinal levels, which result in abnormal forces, stress shielding, and hypermobility at the adjacent levels. In addition, as most patients undergoing these surgeries are osteoporotic, screw loosening at the index level is a complication that commonly accompanies adjacent-level disease. Recent studies indicate that a rod with lower rigidity than that of titanium may help to overcome these detrimental effects at the adjacent level. The present study was conducted in vitro using 12 L1-S1 specimens divided into groups of six, with each group instrumented with either titanium rods or PEEK (polyetheretherketone) rods. The test protocol included subjecting intact specimens to pure moments of 10 Nm in extension and flexion using an FS20 Biomechanical Spine Test System (Applied Test Systems) followed by hybrid moments on the instrumented specimens to achieve the same L1-S1 motion as that of the intact specimens. During the protocol's later phase, the L4-L5 units from each specimen were segmented for cyclic loading followed by postfatigue kinematic analysis to highlight the differences in motion pre- and postfatigue. The objectives included the in vitro comparison of (1) the adjacent-level motion before and after instrumentation with PEEK and titanium rods and (2) the pre- and postfatigue motion at the instrumented level with PEEK and titanium rods. The results showed that the adjacent levels above the instrumentation caused increased flexion and extension with both PEEK and titanium rods. The postfatigue kinematic data showed that the motion at the instrumented level (L4-L5) increased significantly in both flexion and extension compared to prefatigue motion in titanium groups. However, there was no significant difference in motion between the pre- and postfatigue data in the PEEK

  14. Elevated interleukin-6 expression levels are associated with intervertebral disc degeneration

    PubMed Central

    DENG, XIAO; ZHAO, FENG; KANG, BAOLIN; ZHANG, XIN

    2016-01-01

    The present study aimed to investigate whether serum interleukin-6 (IL-6) expression levels were associated with the onset and progression of intervertebral disc degeneration (IDD). A comprehensive meta-analysis of the scientific literature from numerous electronic databases was performed, in order to obtain published studies associated with the topic of interest. Relevant case-control studies that had previously assessed a correlation between IL-6 expression levels and IDD were identified using predetermined inclusion and exclusion criteria. The STATA version 12.0 software was used for statistical analysis of the extracted data. A total of 112 studies were initially retrieved, with eight studies meeting the inclusion criteria. These contained a total of 392 subjects, of which 263 were patients with IDD and 129 were healthy controls. A meta-analysis of the eight studies demonstrated that serum IL-6 protein expression levels may be associated with IDD, and this was irrespective of IDD subtype (bulging, protrusion, or sequestration). Notably, serum expression levels of the IL-6 protein were upregulated in intervertebral disc (IVD) protrusion tissue, as compared with normal IVD tissue; thus suggesting that IL-6 may have an important role in the pathophysiological process of IDD. PMID:27073460

  15. The Association between the Lipids Levels in Blood and Risk of Age-Related Macular Degeneration

    PubMed Central

    Wang, Yafeng; Wang, Mingxu; Zhang, Xiaoqing; Zhang, Qianyu; Nie, Jing; Zhang, Ming; Liu, Xiaohong; Ma, Le

    2016-01-01

    Lipid metabolism may be involved in the pathogenic mechanism of age-related macular degeneration (AMD). However, conflicting results have been reported in the associations of AMD with blood lipids. We performed a meta-analysis including a total of 19 studies to evaluate associations between blood lipids and this disease. The result reported that the high level of high-density lipoprotein cholesterol (HDL-C) obtained with an increment of 1 mmol/L could result in a significantly increase in the AMD risk of approximately 18% (relative risk (RR), 1.18; 95% confidence interval (CI), 1.01 to 1.35; I2 = 53.8%; p = 0.007). High levels of total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG) were significantly associated with a decreased risk of AMD (RRs ranging from 0.92 to 0.95; all p < 0.05). The stratified analysis based on AMD subtypes showed that these blood lipids were only significantly associated with the risk of early AMD (all p < 0.05). The association between the blood lipids and AMD risk did not differ substantially based on the other characteristics of the participants. A high HDL-C level was associated with an increased AMD risk, whereas participants with high TC, LDL-C, and TG concentrations may show a decreased risk for this disease. Further well-designed large studies are warranted to confirm the conclusions. PMID:27782072

  16. Levels of biomarkers correlate with magnetic resonance imaging progression of knee cartilage degeneration: a study on canine.

    PubMed

    Qi, Chang; Changlin, Huang

    2007-07-01

    To examine the association between levers of cartilage oligomeric matrix protein (COMP), matrix metalloproteinases-1 (MMP-1), matrix metalloproteinases-3 (MMP-3), tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) in serum and synovial fluid, and MR imaging of cartilage degeneration in knee joint, and to understand the effects of movement training with different intensity on cartilage of knee joint. 20 adult canines were randomly divided into three groups (8 in the light training group; 8 in the intensive training group; 4 in the control group), and canines of the two training groups were trained daily at different intensity. The training lasted for 10 weeks in all. Magnetic resonance imaging (MRI) examinations were performed regularly (2, 4, 6, 8, 10 week) to investigate the changes of articular cartilage in the canine knee, while concentrations of COMP, MMP-1, MMP-3, TIMP-1 in serum and synovial fluid were measured by ELISA assays. We could find imaging changes of cartilage degeneration in both the training groups by MRI examination during training period, compared with the control group. However, there was no significant difference between these two training groups. Elevations of levels of COMP, MMP-1, MMP-3, TIMP-1, MMP-3/TIMP-1 were seen in serum and synovial fluid after training, and their levels had obvious association with knee MRI grades of cartilage lesion. Furthermore, there were statistically significant associations between biomarkers levels in serum and in synovial fluid. Long-time and high-intensity movement training induces cartilage degeneration in knee joint. Within the intensity extent applied in this study, knee cartilage degeneration caused by light training or intensive training has no difference in MR imaging, but has a comparatively obvious difference in biomarkers level. To detect articular cartilage degeneration in early stage and monitor pathological process, the associated application of several biomarkers has a very good practical

  17. Historical change and future scenarios of sea level rise in Macau and adjacent waters

    NASA Astrophysics Data System (ADS)

    Wang, Lin; Huang, Gang; Zhou, Wen; Chen, Wen

    2016-04-01

    Against a background of climate change, Macau is very exposed to sea level rise (SLR) because of its low elevation, small size, and ongoing land reclamation. Therefore, we evaluate sea level changes in Macau, both historical and, especially, possible future scenarios, aiming to provide knowledge and a framework to help accommodate and protect against future SLR. Sea level in Macau is now rising at an accelerated rate: 1.35 mm yr-1 over 1925-2010 and jumping to 4.2 mm yr-1 over 1970-2010, which outpaces the rise in global mean sea level. In addition, vertical land movement in Macau contributes little to local sea level change. In the future, the rate of SLR in Macau will be about 20% higher than the global average, as a consequence of a greater local warming tendency and strengthened northward winds. Specifically, the sea level is projected to rise 8-12, 22-51 and 35-118 cm by 2020, 2060 and 2100, respectively, depending on the emissions scenario and climate sensitivity. Under the +8.5 W m-2 Representative Concentration Pathway (RCP8.5) scenario the increase in sea level by 2100 will reach 65-118 cm—double that under RCP2.6. Moreover, the SLR will accelerate under RCP6.0 and RCP8.5, while remaining at a moderate and steady rate under RCP4.5 and RCP2.6. The key source of uncertainty stems from the emissions scenario and climate sensitivity, among which the discrepancies in SLR are small during the first half of the 21st century but begin to diverge thereafter.

  18. Cerebrospinal fluid 3,4-dihydroxyphenylacetic acid level after tolcapone administration as an indicator of nigrostriatal degeneration.

    PubMed

    Thiffault, Christine; Langston, J William; Di Monte, Donato A

    2003-09-01

    The development of reliable biological markers of nigrostriatal degeneration has important implications from both experimental and clinical viewpoints, since such biomarkers could be used for diagnostic and monitoring purposes in models of parkinsonism as well as in Parkinson's disease patients. In this study, levels of the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) were measured in the cerebrospinal fluid (CSF) of normal and parkinsonian squirrel monkeys in order to assess their reliability as indicators of nigrostriatal injury. In particular, we tested the hypothesis that these measurements may become more accurate by inhibiting catecholamine-O-methyltransferase (COMT) activity and therefore blocking the conversion of DOPAC to homovanillic acid. Oral administration of the COMT inhibitor tolcapone (2 doses of 15 mg/kg each with a 4-h interval) significantly reduced enzyme activity in the monkey brain. Tolcapone treatment enhanced CSF DOPAC concentrations in unlesioned animals (by approximately four times) as well as monkeys rendered parkinsonian after severe nigrostriatal dopaminergic injury caused by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Importantly, however, COMT inhibition greatly magnified the differences in CSF DOPAC levels between control and parkinsonian monkeys, since MPTP-induced DOPAC depletion was 35% in the absence vs >60% in the presence of tolcapone. Thus, tolcapone administration enhances the detection of DOPAC in the CSF and, by doing so, improves the reliability of CSF DOPAC as a marker of nigrostriatal degeneration.

  19. Effects of Withdrawals on Ground-Water Levels in Southern Maryland and the Adjacent Eastern Shore, 1980-2005

    USGS Publications Warehouse

    Soeder, Daniel J.; Raffensperger, Jeff P.; Nardi, Mark R.

    2007-01-01

    Ground water is the primary source of water supply in most areas of Maryland?s Atlantic Coastal Plain, including Southern Maryland. The counties in this area are experiencing some of the most rapid growth and development in the State, resulting in an increased demand for ground-water production. The cooperative, basic water-data program of the U.S. Geological Survey and the Maryland Geological Survey has collected long-term observations of ground-water levels in Southern Maryland and parts of the Eastern Shore for many decades. Additional water-level observations were made by both agencies beginning in the 1970s, under the Power Plant Research Program of the Maryland Department of Natural Resources. These long-term water levels commonly show significant declines over several decades, which are attributed to ground-water withdrawals. Ground-water-level trends since 1980 in major Coastal Plain aquifers such as the Piney Point-Nanjemoy, Aquia, Magothy, upper Patapsco, lower Patapsco, and Patuxent were compared to water use and withdrawal data. Potentiometric surface maps show that most of the declines in ground-water levels can be directly related to effects from major pumping centers. There is also evidence that deep drawdowns in some pumped aquifers may be causing declines in adjacent, unpumped aquifers. Water-level hydrographs of many wells in Southern Maryland show linear declines in levels year after year, instead of the gradual leveling-off that would be expected as the aquifers equilibrate with pumping. A continual increase in the volumes of water being withdrawn from the aquifers is one explanation for why they are not reaching equilibrium. Although reported ground-water production in Southern Maryland has increased somewhat over the past several decades, the reported increases are often not large enough to account for the observed water-level declines. Numerical modeling simulations indicate that a steady, annual increase in the number of small wells could

  20. Altered Levels of Visinin-Like Protein 1 Correspond to Regional Neuronal Loss in Alzheimer Disease and Frontotemporal Lobar Degeneration.

    PubMed

    Kirkwood, Caitlin M; MacDonald, Matthew L; Schempf, Tadhg A; Vatsavayi, Anil V; Ikonomovic, Milos D; Koppel, Jeremy L; Ding, Ying; Sun, Mai; Kofler, Julia K; Lopez, Oscar L; Yates, Nathan A; Sweet, Robert A

    2016-02-01

    Recent studies have implicated the neuronal calcium-sensing protein visinin-like 1 protein (Vilip-1) as a peripheral biomarker in Alzheimer disease (AD), but little is known about expression of Vilip-1 in the brains of patients with AD. We used targeted and quantitative mass spectrometry to measure Vilip-1 peptide levels in the entorhinal cortex (ERC) and the superior frontal gyrus (SF) from cases with early to moderate stage AD, frontotemporal lobar degeneration (FTLD), and cognitively and neuropathologically normal elderly controls. We found that Vilip-1 levels were significantly lower in the ERC, but not in SF, of AD subjects compared to normal controls. In FTLD cases, Vilip-1 levels in the SF were significantly lower than in normal controls. These findings suggest a unique role for cerebrospinal fluid Vilip-1 as a biomarker of ERC neuron loss in AD.

  1. Striatonigral Degeneration

    MedlinePlus

    ... disease, striatonigral degeneration is not responsive to levodopa. Dopamine and anticholinergics provide some benefit. Generally, treatment is ... disease, striatonigral degeneration is not responsive to levodopa. Dopamine and anticholinergics provide some benefit. Generally, treatment is ...

  2. Macular degeneration

    MedlinePlus Videos and Cool Tools

    ... at the center of the field of vision. Macular degeneration results from a partial breakdown of the insulating ... choroid layer of blood vessels behind the retina. Macular degeneration results in the loss of central vision only.

  3. Nitrate-nitrogen levels in rural drinking water: Is there an association with age-related macular degeneration?

    PubMed

    Klein, Barbara E K; McElroy, Jane A; Klein, Ronald; Howard, Kerri P; Lee, Kristine E

    2013-01-01

    We examined the association of nitrate-nitrogen exposure from rural private drinking water and incidence of age-related macular degeneration (AMD). All participants in the Beaver Dam Eye Study (53916 improvement plan code) completed a questionnaire and had an ocular examination including standardized, graded fundus photographs at five examinations. Only information from rural residents in that study are included in this report. Data from an environmental monitoring study with probabilistic-based agro-chemical sampling, including nitrate-nitrogen, of rural private drinking water were available. Incidence of early AMD was associated with elevated nitrate-nitrogen levels in rural private drinking water supply (10.0% for low, 19.2% for medium, and 26.1% for high nitrate-nitrogen level in the right eye). The odds ratios (ORs) were 1.77 (95% confidence interval [CI]: 1.12-2.78) for medium and 2.88 (95% CI: 1.59-5.23) for high nitrate-nitrogen level. Incidence of late AMD was increased for those with medium or high levels of nitrate-nitrogen compared to low levels (2.3% for low and 5.1% for the medium or high nitrate-nitrogen level, for the right eye). The OR for medium or high nitrate-nitrogen groups was 2.80 (95% CI: 1.07-7.31) compared to the low nitrate-nitrogen group.

  4. The Effects of Age, Gender, Ethnicity, and Spinal Level on the Rate of Intervertebral Disc Degeneration. A review of 1712 Intervertebral Discs

    PubMed Central

    Siemionow, Krzysztof; An, Howard; Masuda, Koichi; Andersson, Gunnar; Cs-Szabo, Gabriella

    2010-01-01

    Study Design A gross anatomical and magnetic resonance imaging (MRI) study of intervertebral disc (IVD) degeneration in fresh cadaveric lumbar spines. Objective The purpose of this study was to find the rate of IVD degeneration. Summary of Background Data Age, sex, race, and lumbar level are among some of the factors that play a role in IVD degeneration. The rate at which IVDs degenerate is unknown. Methods Complete lumbar spine segments (T11/12 to S1) were received within 24 hours of death. The nucleus pulposus, annulus fibrosus, cartilaginous and bony end-plate, and the peripheral verterbral body were assessed with MRI and IVD degeneration was graded by two observers from grade 1(nondegenerated) to grade 5(severely degenerated) based on a scale developed by Tanaka et al. The specimens were then sectioned and gross anatomical evaluation was performed according to Thompson et al. Results 433 donors and 1712 IVDs were analyzed. There were 366 Caucasians, 47 Africans, 16 Hispanics, 4 Asian. There were 306 males and 127 females. The age range was 14–81 years, (average 60.5+/−11.3). For donors greater than age 40, the L5/S1 IVD degenerated at a significantly faster rate of 0.043/year compared to 0.031, 0.034, 0.033, 0.027 for L12, L23, L34, L45, respectively. For donors younger than 40, L5/S1 IVD degenerated at a significantly faster rate of 0.141/year compared to 0.033,0.021, 0.031, 0.050 for L12, L23, L34, L45, respectively. Multiple regression analysis revealed that gender had no significant effect on IVD degeneration whereas African ethnicity was associated with lower Thompson score at L12, L23, L34, L45 when compared to Caucasians. Conclusions The relatively early degeneration at L5-S1 in all races and lower Thompson grade in donors of African ethnicity needs further investigation. Factors such as sagittal alignment, facet joint arthritis, and genetics potentially play a role in IVD degeneration. PMID:21217432

  5. High breast milk levels of polychlorinated biphenyls (PCBs) among four women living adjacent to a PCB-contaminated waste site.

    PubMed Central

    Korrick, S A; Altshul, L

    1998-01-01

    As a consequence of contamination by effluents from local electronics manufacturing facilities, the New Bedford Harbor and estuary in southeastern Massachusetts is among the sites in the United States that are considered the most highly contaminated by polychlorinated biphenyls (PCBs). Since 1993, measures of intrauterine PCB exposure have been obtained for a sample of New Bedford area infants. Among 122 mother-infant pairs, we identified four milk samples with total PCB levels that were significantly higher than the rest, with estimated total PCBs ranging from 1,100 to 2,400 ng/g milk fat compared with an overall mean of 320 ng/g milk fat for the 122 women. The congener profile and history of one case was consistent with past occupational PCB exposures. Otherwise, the source of PCB exposures in these cases was difficult to specify. Environmental exposures including those from fish consumption were likely, whereas residence adjacent to a PCB-contaminated site was considered an unlikely exposure source. In all four cases, the infants were full-term, healthy newborns. Because the developing nervous system is believed to be particularly susceptible to PCBs (for example, prenatal PCB exposures have been associated with prematurity, decrements in birth weight and gestation time, and behavioral and developmental deficits in later infancy and childhood, including decrements in IQ), it is critical to ascertain if breast-feeding is a health risk for the women's infants. Despite the potential for large postnatal PCB exposures via breast milk, there is limited evidence of significant developmental toxicity associated with the transmission of moderate PCB concentrations through breast milk. Breast-feeding is associated with substantial health benefits including better cognitive skills among breast-fed compared with formula-fed infants. We conclude, based on evidence from other studies, that the benefits of breast-feeding probably outweigh any risk from PCB exposures via breast

  6. MicroRNA-15b Modulates Cellular ATP Levels and Degenerates Mitochondria via Arl2 in Neonatal Rat Cardiac Myocytes*

    PubMed Central

    Nishi, Hitoo; Ono, Koh; Iwanaga, Yoshitaka; Horie, Takahiro; Nagao, Kazuya; Takemura, Genzou; Kinoshita, Minako; Kuwabara, Yasuhide; Mori, Rieko Takanabe; Hasegawa, Koji; Kita, Toru; Kimura, Takeshi

    2010-01-01

    MicroRNAs (miRNAs or miRs) are small, non-coding RNAs that modulate mRNA stability and post-transcriptional translation. A growing body of evidence indicates that specific miRNAs can affect the cellular function of cardiomyocytes. In the present study, miRNAs that are highly expressed in the heart were overexpressed in neonatal rat ventricular myocytes, and cellular ATP levels were assessed. As a result, miR-15b, -16, -195, and -424, which have the same seed sequence, the most critical determinant of miRNA targeting, decreased cellular ATP levels. These results suggest that these miRNAs could specifically down-regulate the same target genes and consequently decrease cellular ATP levels. Through a bioinformatics approach, ADP-ribosylation factor-like 2 (Arl2) was identified as a potential target of miR-15b. It has already been shown that Arl2 localizes to adenine nucleotide transporter 1, the exchanger of ADP/ATP in mitochondria. Overexpression of miR-15b, -16, -195, and -424 suppressed the activity of a luciferase reporter construct fused with the 3′-untranslated region of Arl2. In addition, miR-15b overexpression decreased Arl2 mRNA and protein expression levels. The effects of Arl2 siRNA on cellular ATP levels were the same as those of miR-15b, and the expression of Arl2 could restore ATP levels reduced by miR-15b. A loss-of-function study of miR-15b resulted in increased Arl2 protein and cellular ATP levels. Electron microscopic analysis revealed that mitochondria became degenerated in cardiomyocytes that had been transduced with miR-15b and Arl2 siRNA. The present results suggest that miR-15b may decrease mitochondrial integrity by targeting Arl2 in the heart. PMID:20007690

  7. Effects of fluctuating river-pool stages on ground-water levels in the adjacent alluvial aquifer in the lower Arkansas River, Arkansas

    USGS Publications Warehouse

    Freiwald, D.A.; Grosz, G.D.

    1988-01-01

    The U.S. Geological Survey conducted a study in cooperation with the U.S. Army Corps of Engineers to determine the effect of fluctuating the lower Arkansas River. A network of 41 wells was used to delineate 4 cross sections adjacent to river pools 2 and 5 of the McClellan-Kerr Arkansas River Navigation System to examine groundwater levels at various distances from the river. The hydraulic gradient of water levels in the alluvial aquifer along these cross sections indicates that the river is losing water to the adjacent aquifer. The effect on groundwater levels in the alluvial aquifer caused by pool-stage fluctuations was most pronounced at distances less than about 2 miles from the Arkansas River. At distances greater than about 2 miles, the changes in groundwater levels probably were the result of water levels rising in the aquifer since the heavy summer irrigation withdrawals have ceased. An equation useful for estimating the distribution of head change an aquifer in response to river-pool-stage changes, was applied to the study area to estimate the effect of a 1-foot rise in pool stage on water levels in the adjacent alluvial aquifer after equilibrium conditions have been established. The theoretical head change (rise) in the aquifer was estimated to range from 1-foot at the Arkansas River to 0.57 foot at a distance of 5 miles away from the river. (USGS)

  8. Application of quasi-degenerate perturbation theory to the calculation of rotational energy levels of methane vibrational polyads

    SciTech Connect

    Cassam-Chenaï, P. Rousseau, G.; Ilmane, A.; Bouret, Y.; Rey, M.

    2015-07-21

    In previous works, we have introduced an alternative perturbation scheme to find approximate solutions of the spectral problem for the rotation-vibration molecular Hamiltonian. An important feature of our approach is that the zero order Hamiltonian is the direct product of a purely vibrational Hamiltonian with the identity on the rotational degrees of freedom. The convergence of our method for the methane vibrational ground state was very satisfactory and our predictions were quantitative. In the present article, we provide further details on the implementation of the method in the degenerate and quasi-degenerate cases. The quasi-degenerate version of the method is tested on excited polyads of methane, and the results are assessed with respect to a variational treatment. The optimal choice of the size of quasi-degenerate spaces is determined by a trade-off between speed of convergence of the perturbation series and the computational effort to obtain the effective super-Hamiltonian.

  9. Loosely coupled level sets for retinal layers and drusen segmentation in subjects with dry age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Novosel, Jelena; Wang, Ziyuan; de Jong, Henk; Vermeer, Koenraad A.; van Vliet, Lucas J.

    2016-03-01

    Optical coherence tomography (OCT) is used to produce high-resolution three-dimensional images of the retina, which permit the investigation of retinal irregularities. In dry age-related macular degeneration (AMD), a chronic eye disease that causes central vision loss, disruptions such as drusen and changes in retinal layer thicknesses occur which could be used as biomarkers for disease monitoring and diagnosis. Due to the topology disrupting pathology, existing segmentation methods often fail. Here, we present a solution for the segmentation of retinal layers in dry AMD subjects by extending our previously presented loosely coupled level sets framework which operates on attenuation coefficients. In eyes affected by AMD, Bruch's membrane becomes visible only below the drusen and our segmentation framework is adapted to delineate such a partially discernible interface. Furthermore, the initialization stage, which tentatively segments five interfaces, is modified to accommodate the appearance of drusen. This stage is based on Dijkstra's algorithm and combines prior knowledge on the shape of the interface, gradient and attenuation coefficient in the newly proposed cost function. This prior knowledge is incorporated by varying the weights for horizontal, diagonal and vertical edges. Finally, quantitative evaluation of the accuracy shows a good agreement between manual and automated segmentation.

  10. Adjacent Segment Pathology after Anterior Cervical Fusion

    PubMed Central

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

    2016-01-01

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

  11. Water-quality, water-level, and lake-bottom-sediment data collected from the defense fuel supply point and adjacent properties, Hanahan, South Carolina, 1990-96

    USGS Publications Warehouse

    Petkewich, M.D.; Vroblesky, D.A.; Robertson, J.F.; Bradley, P.M.

    1997-01-01

    A 9-year scientific investigation to determine the potential for biore-mediation of ground-water contamination and to monitor the effectiveness of an engineered bioremediation system located at the Defense Fuel Supply Point and adjacent properties in Hanahan, S.C., has culminated in the collection of abundant water-quality and water-level data.This report presents the analytical results of the study that monitored the changes in surface- and ground-water quality and water-table elevations in the study area from December 1990 to January 1996. This report also presents analytical results of lake-bottom sediments collected in the study area.

  12. Ground-Water Hydrographs and 5-Year Ground-Water-Level Changes, 1984-93, for Selected Areas In and Adjacent to New Mexico

    USGS Publications Warehouse

    Wilkins, D.W.; Garcia, Benjamin M.

    1995-01-01

    A cooperative observation-well monitoring program was begun in New Mexico in 1925 between the U.S. Geological Survey and the New Mexico State Engineer Office. The majority of the wells are located in New Mexico; however, a few are in Texas east of Curry and Roosevelt County, New Mexico, and in Colorado along the Rio Grande. The program presently includes 22 wells equipped with continuous water-level recorders and 34 monitoring areas in which selected wells are measured periodically, usually every 5 years, to record changes in ground-water levels. These monitoring areas are those where ground water is used in large quantities for irrigation, municipal, or industrial purposes. Water-level data and water-level changes computed from these data are used to determine areas of ground-water-level rises and declines. This information is necessary for management of ground-water resources in New Mexico. Included in this report are hydrographs of ground-water levels obtained from 22 wells equipped with continuous water-level recorders and maps of ground-water-level changes computed for a 5-year period in each of 34 monitoring areas. Well locations and ground-water-level data for a 5-year period are listed in tables for each monitoring area. Where available, plots of annual precipitation data for climatological stations within or adjacent to each monitoring area are included.

  13. Electromagnetically induced absorption and transparency in degenerate two level systems of metastable Kr atoms and measurement of Landé g-factor

    NASA Astrophysics Data System (ADS)

    Kale, Y. B.; Tiwari, V. B.; Mishra, S. R.; Singh, S.; Rawat, H. S.

    2016-12-01

    We report electromagnetically induced absorption (EIA) and transparency (EIT) resonances of sub-natural linewidth in degenerate two level systems (DTLSs) of metastable 84Kr (84Kr*) and 83Kr (83Kr*) atoms. Using the spectrally narrow EIA signals obtained corresponding to the closed hyperfine transition 4p55s[3/2]2(F=13/2) to 4p55p[5/2]3(F‧ = 15 / 2) in 83Kr* atom, we have measured the Landé g-factor (gF) for the lower hyperfine level involved in this transition by application of small values of magnetic field of few Gauss.

  14. Attachment Levels and Crevicular Depths at the Distal of Mandibular Second Molars Following Removal of Adjacent Third Molars.

    DTIC Science & Technology

    1981-02-01

    k AAD-AD95 500 ARMY INST OF DENTAL RESEARCH WASHINGTON OC F/G 6/5-7 TACHMENT LEVELS AND CREVICULAR DEPTHS AT THE DISTAL OF MANDIB--E1CCU)I FEB Al W H... Dental ResearchA&WOKUINMBR C Walter Reed Army Medical Center 6Z 35l62775A82YOO 007 Washington, DC 20012 10 1 CONTROLLING OFFICE NAME AND ADDRESS - RPR...Resident in Periodontics, United States Army Institute of Dental Research, Walter Reed Army Medical Center, Washington, DC Director, Periodontics Residency

  15. Tyro3 Modulates Mertk-Associated Retinal Degeneration.

    PubMed

    Vollrath, Douglas; Yasumura, Douglas; Benchorin, Gillie; Matthes, Michael T; Feng, Wei; Nguyen, Natalie M; Sedano, Cecilia D; Calton, Melissa A; LaVail, Matthew M

    2015-12-01

    Inherited photoreceptor degenerations (IPDs) are the most genetically heterogeneous of Mendelian diseases. Many IPDs exhibit substantial phenotypic variability, but the basis is usually unknown. Mutations in MERTK cause recessive IPD phenotypes associated with the RP38 locus. We have identified a murine genetic modifier of Mertk-associated photoreceptor degeneration, the C57BL/6 (B6) allele of which acts as a suppressor. Photoreceptors degenerate rapidly in Mertk-deficient animals homozygous for the 129P2/Ola (129) modifier allele, whereas animals heterozygous for B6 and 129 modifier alleles exhibit an unusual intermixing of degenerating and preserved retinal regions, with females more severely affected than males. Mertk-deficient mice homozygous for the B6 modifier allele display degeneration only in the far periphery, even at 8 months of age, and have improved retinal function compared to animals homozygous for the 129 allele. We genetically mapped the modifier to an approximately 2-megabase critical interval that includes Tyro3, a paralog of Mertk. Tyro3 expression in the outer retina varies with modifier genotype in a manner characteristic of a cis-acting expression quantitative trait locus (eQTL), with the B6 allele conferring an approximately three-fold higher expression level. Loss of Tyro3 function accelerates the pace of photoreceptor degeneration in Mertk knockout mice, and TYRO3 protein is more abundant in the retinal pigment epithelium (RPE) adjacent to preserved central retinal regions of Mertk knockout mice homozygous for the B6 modifier allele. Endogenous human TYRO3 protein co-localizes with nascent photoreceptor outer segment (POS) phagosomes in a primary RPE cell culture assay, and expression of murine Tyro3 in cultured cells stimulates phagocytic ingestion of POS. Our findings demonstrate that Tyro3 gene dosage modulates Mertk-associated retinal degeneration, provide strong evidence for a direct role for TYRO3 in RPE phagocytosis, and suggest

  16. Striatopallidonigral degeneration

    PubMed Central

    Bell, W. E.; McCormick, W. F.

    1971-01-01

    A 15-year-old girl is described with a sporadic, progressive illness manifested by unilateral limb rigidity and dystonia. Obvious dysarthria and some intellectual decline also were noted. Neuropathological findings included gross discoloration and shrinkage of the pallida and, microscopically, profound neuronal loss and gliosis of the caudata and putamena, with less severe neuronal loss from the pallida and substantia nigra. The disease bears some similarities to striatonigral degeneration, but certain clinical and morphological differences justify its consideration as a separate syndrome. ImagesFIG. 1FIG. 2FIG. 3FIG. 4FIG. 5 PMID:5565467

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

    PubMed

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

    2017-02-01

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

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

    PubMed Central

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

    2017-01-01

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

  19. Macular degeneration (image)

    MedlinePlus

    Macular degeneration is a disease of the retina that affects the macula in the back of the eye. ... see fine details. There are two types of macular degeneration, dry and wet. Dry macular degeneration is more ...

  20. Wet Macular Degeneration

    MedlinePlus

    Wet macular degeneration Overview By Mayo Clinic Staff Wet macular degeneration is a chronic eye disease that causes blurred vision ... of the retina responsible for central vision. Wet macular degeneration is one of two types of age-related ...

  1. Dry Macular Degeneration

    MedlinePlus

    Dry macular degeneration Overview By Mayo Clinic Staff Dry macular degeneration is a common eye disorder among people over 65. ... vision in your direct line of sight. Dry macular degeneration may first develop in one eye and then ...

  2. Diffuse aneurysmal degeneration of the brachial artery after long-standing high-flow arteriovenous fistula closure for hemodialysis at elbow level.

    PubMed

    De Santis, Francesco; Martini, Guido; Mani, Gabriele; Bernhard, Othmar

    2014-07-01

    While the possibility of development of a panarterial dilatation proximal to a long-standing high-flow posttraumatic arteriovenous fistula is well known, to the best of our knowledge, this event has never been described after vascular access for hemodialysis closure. We describe a man in whom a diffuse aneurysmal degeneration of the brachial artery has been highlighted 6 months after long-standing high-flow arteriovenous fistula closure. A 47-year-old man developed a painful pulsatile mass in the anterior distal third of his arm 6 months after long-standing high-flow arteriovenous fistula closure at the level of his elbow. A computed tomography scan revealed multiple "true" aneurysms of the brachial artery (BA) that appeared enlarged in toto. One of these aneurysms (near the BA bifurcation) presented with significant thrombus stratification. Surgery was recommended because of the major risk of peripheral embolization. Considering the anatomic characteristics of both the BA and aneurysm, no arterial substitution was performed and, after removal of the thrombus, the aneurysm diameter was reduced via direct arterial wall suture. The patient was discharged under oral anticoagulation. Aneurysmal degeneration of the donor artery after vascular access is relatively rare but represents a challenging problem. Operative or conservative management of these aneurysms should evaluate both the possible aneurysm-related complications and the feasibility of vascular reconstruction. In this context, the risk of additional donor artery and/or vascular reconstruction enlargement over time should also be considered.

  3. Levels of iron, silver, zinc, and lead in oranges and avocados from two gold-rich towns compared with levels in an adjacent gold-deficient town

    SciTech Connect

    Golow, A.A.; Laryea, J.N. )

    1994-09-01

    Fruits such as oranges and avocados are important sources of drinks and food in the Ghanaian Society. If such fruits contain various types of metals they may augument the types and amounts of them in the human body. The metals in fruits may depend on what is in the soils from which they are grown. If the soils contain toxic metals like lead, mercury and cadmium then the consumers may be poisoned as happened in the [open quotes]Ouchi - ouchi[close quotes], disease in Japan and similar episodes. In the area under study, the Geological Survey indicates the presence of 2.5 ppm of lead, 10 - 20 ppm of copper and less than 15 ppm of nickel. Silver, not reported in commercial amounts, is a byproduct of gold productions at Obuasi. Since copper and nickel are presented in the area traces of silver will certainly occur. In the same manner zinc is usually associated with lead as sulphide of zinc blend trace amounts of it are likely to occur in the area. Of the four metals measured, iron and zinc essential for citrus. The extractable iron and zinc in the area of study were 90 and 1.8 mg/kg, levels on the low side for the healthy growth of crops. The investigation reported here is the comparison of the levels of some metals in oranges and avocados from farms in Obuasi and Konongo with those from farms in Kumasi City. This is a part of a project aimed at finding out differences in the metal contents of various food crops grown in various regions of the country. Konongo and Obuasi have soils which are rich in gold but Kumasi city, which is not too distant from these towns, does not have gold in its soil. 18 refs., 1 tab.

  4. Mitochondrial DNA Variants Mediate Energy Production and Expression Levels for CFH, C3 and EFEMP1 Genes: Implications for Age-Related Macular Degeneration

    PubMed Central

    Kenney, M. Cristina; Chwa, Marilyn; Atilano, Shari R.; Pavlis, Janelle M.; Falatoonzadeh, Payam; Ramirez, Claudio; Malik, Deepika; Hsu, Tiffany; Woo, Grace; Soe, Kyaw; Nesburn, Anthony B.; Boyer, David S.; Kuppermann, Baruch D.; Jazwinski, S. Michal; Miceli, Michael V.; Wallace, Douglas C.; Udar, Nitin

    2013-01-01

    Background Mitochondrial dysfunction is associated with the development and progression of age-related macular degeneration (AMD). Recent studies using populations from the United States and Australia have demonstrated that AMD is associated with mitochondrial (mt) DNA haplogroups (as defined by combinations of mtDNA polymorphisms) that represent Northern European Caucasians. The aim of this study was to use the cytoplasmic hybrid (cybrid) model to investigate the molecular and biological functional consequences that occur when comparing the mtDNA H haplogroup (protective for AMD) versus J haplogroup (high risk for AMD). Methodology/Principal Findings Cybrids were created by introducing mitochondria from individuals with either H or J haplogroups into a human retinal epithelial cell line (ARPE-19) that was devoid of mitochondrial DNA (Rho0). In cybrid lines, all of the cells carry the same nuclear genes but vary in mtDNA content. The J cybrids had significantly lower levels of ATP and reactive oxygen/nitrogen species production, but increased lactate levels and rates of growth. Q-PCR analyses showed J cybrids had decreased expressions for CFH, C3, and EFEMP1 genes, high risk genes for AMD, and higher expression for MYO7A, a gene associated with retinal degeneration in Usher type IB syndrome. The H and J cybrids also have comparatively altered expression of nuclear genes involved in pathways for cell signaling, inflammation, and metabolism. Conclusion/Significance Our findings demonstrate that mtDNA haplogroup variants mediate not only energy production and cell growth, but also cell signaling for major molecular pathways. These data support the hypothesis that mtDNA variants play important roles in numerous cellular functions and disease processes, including AMD. PMID:23365660

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

    PubMed

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

    2017-04-01

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

  6. Environmental data package for ORNL Solid Waste Storage Area Four, the adjacent intermediate-level liquid waste transfer line, and the liquid waste pilot pit area

    SciTech Connect

    Davis, E.C.; Shoun, R.R.

    1986-09-01

    The Oak Ridge National Laboratory Remedial Action Program has determined through its review of past environmental studies that Solid Waste Storage Area Four (SWSA-4) continually releases radioactivity to White Oak Creek and therefore requires application of the site stabilization and remedial actions outlined under the 3004u provisions of the Resource Conservation and Recovery Act. Under these provisions, a Remedial Investigation/Feasibility Study (RI/FS) forms the basis for determining the extent of actions. This report assembles available historical and environmental data relative to the SWSA-4 waste area grouping (WAG), which includes the 9.3-ha SWSA-4 site, the adjacent abandoned intermediate-level liquid waste transfer line, and the experimental pilot pit area. The rationale for grouping these three waste management units into the SWSA-4 WAG is the fact that they each lie in the same hydrologic unit and share a common tributary to White Oak Creek. The results of this compilation demonstrate that although a considerable number of studies have been carried out in SWSA-4, needs such as installation of water quality wells and continued monitoring and reporting of hydrologic data still exist. These needs will become even more critical as the RI/FS process proceeds and remedial measures for the site are considered. Fewer studies have been carried out to characterize the extent of contamination at the waste transfer line and the pilot pit area. Alternatives for characterizing and stabilizing these two minor components of the SWSA-4 WAG are presented; however, extensive remedial actions do not appear to be warranted.

  7. Effects of closure of an urban level I trauma centre on adjacent hospitals and local injury mortality: a retrospective, observational study

    PubMed Central

    Crandall, Marie; Sharp, Douglas; Wei, Xiong; Nathens, Avery; Hsia, Renee Y

    2016-01-01

    Objective To determine the association of the Martin Luther King Jr Hospital (MLK) closure on the distribution of admissions on adjacent trauma centres, and injury mortality rates in these centres and within the county. Design Observational, retrospective study. Setting Non-public patient-level data from the state of California were obtained for all trauma patients from 1999 to 2009. Geospatial analysis was used to visualise the redistribution of trauma patients to other hospitals after MLK closed. Variance of observed to expected injury mortality using multivariate logistic regression was estimated for the study period. Participants A total of 37 131 trauma patients were admitted to the five major south Los Angeles trauma centres from the MLK service area between 1999 and 2009. Main outcome measures (1) Number and type of trauma admissions to trauma centres in closest proximity to MLK; (2) inhospital injury mortality of trauma patients after the trauma centre closure. Results During and after the MLK closure, trauma admissions increased at three of the four nearby hospitals, particularly admissions for gunshot wounds (GSWs). This redistribution of patient load was accompanied by a dramatic change in the payer mix for surrounding hospitals; one hospital's share of uninsured more than tripled from 12.9% in 1999 to 44.6% by 2009. Overall trauma mortality did not significantly change, but GSW mortality steadily and significantly increased after the closure from 5.0% in 2007 to 7.5% in 2009. Conclusions Though local hospitals experienced a dramatic increase in trauma patient volume, overall mortality for trauma patients did not significantly change after MLK closed. PMID:27165650

  8. Hepatocerebral degeneration

    MedlinePlus

    ... Liver damage can lead to the buildup of ammonia and other toxic materials in the body. This ... Walking instability Laboratory tests may show a high ammonia level in the bloodstream and abnormal liver function. ...

  9. Macular Degeneration Partnership

    MedlinePlus

    ... Age Related Macular Degeneration) Partnership Listen AMD Month Public Service Announcement To raise awareness of AMD, the Macular Degeneration Partnership (MDP) is distributing a public service announcement (PSA) nationwide. Seen through the eyes of a ...

  10. Malnutrition in Alzheimer’s Disease, Dementia with Lewy Bodies, and Frontotemporal Lobar Degeneration: Comparison Using Serum Albumin, Total Protein, and Hemoglobin Level

    PubMed Central

    Hashimoto, Mamoru; Tanaka, Hibiki; Fujise, Noboru; Matsushita, Masateru; Miyagawa, Yusuke; Hatada, Yutaka; Fukuhara, Ryuji; Hasegawa, Noriko; Todani, Shuji; Matsukuma, Kengo; Kawano, Michiyo; Ikeda, Manabu

    2016-01-01

    Malnutrition among dementia patients is an important issue. However, the biochemical markers of malnutrition have not been well studied in this population. The purpose of this study was to compare biochemical blood markers among patients with Alzheimer’s disease (AD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD). A total of 339 dementia outpatients and their family caregivers participated in this study. Low serum albumin was 7.2 times more prevalent among patients with DLB and 10.1 times more prevalent among those with FTLD than among those with AD, with adjustment for age. Low hemoglobin was 9.1 times more common in female DLB patients than in female AD patients, with adjustment for age. The levels of biochemical markers were not significantly correlated with cognitive function. Family caregivers of patients with low total protein, low albumin, or low hemoglobin were asked if the patients had loss of weight or appetite; 96.4% reported no loss of weight or appetite. In conclusion, nutritional status was worse in patients with DLB and FTLD than in those with AD. A multidimensional approach, including blood testing, is needed to assess malnutrition in patients with dementia. PMID:27336725

  11. Macular Degeneration: An Overview.

    ERIC Educational Resources Information Center

    Chalifoux, L. M.

    1991-01-01

    This article presents information on macular degeneration for professionals helping persons with this disease adjust to their visual loss. It covers types of macular degeneration, the etiology of the disease, and its treatment. Also considered are psychosocial problems and other difficulties that persons with age-related macular degeneration face.…

  12. Rare genetic variants in the CFI gene are associated with advanced age-related macular degeneration and commonly result in reduced serum factor I levels.

    PubMed

    Kavanagh, David; Yu, Yi; Schramm, Elizabeth C; Triebwasser, Michael; Wagner, Erin K; Raychaudhuri, Soumya; Daly, Mark J; Atkinson, John P; Seddon, Johanna M

    2015-07-01

    To assess a potential diagnostic and therapeutic biomarker for age-related macular degeneration (AMD), we sequenced the complement factor I gene (CFI) in 2266 individuals with AMD and 1400 without, identifying 231 individuals with rare genetic variants. We evaluated the functional impact by measuring circulating serum factor I (FI) protein levels in individuals with and without rare CFI variants. The burden of very rare (frequency <1/1000) variants in CFI was strongly associated with disease (P = 1.1 × 10(-8)). In addition, we examined eight coding variants with counts ≥5 and saw evidence for association with AMD in three variants. Individuals with advanced AMD carrying a rare CFI variant had lower mean FI compared with non-AMD subjects carrying a variant (P < 0.001). Further new evidence that FI levels drive AMD risk comes from analyses showing individuals with a CFI rare variant and low FI were more likely to have advanced AMD (P = 5.6 × 10(-5)). Controlling for covariates, low FI increased the risk of advanced AMD among those with a variant compared with individuals without advanced AMD with a rare CFI variant (OR 13.6, P = 1.6 × 10(-4)), and also compared with control individuals without a rare CFI variant (OR 19.0, P = 1.1 × 10(-5)). Thus, low FI levels are strongly associated with rare CFI variants and AMD. Enhancing FI activity may be therapeutic and measuring FI provides a screening tool for identifying patients who are most likely to benefit from complement inhibitory therapy.

  13. A level-set method for pathology segmentation in fluorescein angiograms and en face retinal images of patients with age-related macular degeneration

    NASA Astrophysics Data System (ADS)

    Mohammad, Fatimah; Ansari, Rashid; Shahidi, Mahnaz

    2013-03-01

    The visibility and continuity of the inner segment outer segment (ISOS) junction layer of the photoreceptors on spectral domain optical coherence tomography images is known to be related to visual acuity in patients with age-related macular degeneration (AMD). Automatic detection and segmentation of lesions and pathologies in retinal images is crucial for the screening, diagnosis, and follow-up of patients with retinal diseases. One of the challenges of using the classical level-set algorithms for segmentation involves the placement of the initial contour. Manually defining the contour or randomly placing it in the image may lead to segmentation of erroneous structures. It is important to be able to automatically define the contour by using information provided by image features. We explored a level-set method which is based on the classical Chan-Vese model and which utilizes image feature information for automatic contour placement for the segmentation of pathologies in fluorescein angiograms and en face retinal images of the ISOS layer. This was accomplished by exploiting a priori knowledge of the shape and intensity distribution allowing the use of projection profiles to detect the presence of pathologies that are characterized by intensity differences with surrounding areas in retinal images. We first tested our method by applying it to fluorescein angiograms. We then applied our method to en face retinal images of patients with AMD. The experimental results included demonstrate that the proposed method provided a quick and improved outcome as compared to the classical Chan-Vese method in which the initial contour is randomly placed, thus indicating the potential to provide a more accurate and detailed view of changes in pathologies due to disease progression and treatment.

  14. Risk Factors Associated with Adjacent and Remote- Level Pathologic Vertebral Compression Fracture Following Balloon Kyphoplasty: 2-Year Follow-Up Comparison Versus Conservative Treatment.

    PubMed

    Faloon, Michael J; Ruoff, Mark; Deshpande, Chetan; Hohman, Donald; Dunn, Conor; Beckloff, Nicholas; Patel, Dipak V

    2015-01-01

    Vertebral compression fractures are a significant source of morbidity and mortality among patients of all age groups. These fractures result in both acute and chronic pain. Patients who sustain such fractures are known to suffer from more comorbidities and have a higher mortality rate compared with healthy people in the same age group. In recent years, balloon kyphoplasty has become a popular method for treating vertebral compression fractures. However, as longer-term follow-up becomes available, the effects of cement augmentation on adjacent spinal segments require investigation. Here, we have performed a retrospective chart review of 258 consecutive patients with pathologic vertebral compression fractures secondary to osteoporosis, treated by either conservative measures or balloon kyphoplasty with polymethylmethacrylate cement augmentation. Multivariate analysis of patient comorbidities was performed to assess the risks associated with subsequent adjacent and remote compression fracture at a minimum of 2 years follow-up. A total of 258 patients had 361 vertebral compression fractures. A total of 121 patients were treated nonoperatively and 137 underwent balloon kyphoplasty with polymethylmethacrylate cement augmentation. The mean follow-up for both cohorts was 2.7 years (range, 2-6 years). The kyphoplasty cohort was significantly older than the nonoperative cohort (mean age, 78.5 versus 74.2 years; p = 0.02), had 24 more patients with diabetes mellitus (37 versus 13; p = 0.05), and had 34 more patients with a history of smoking (50 versus 16; p = 0.05). However, the kyphoplasty cohort had less patients with a history of non-steroidal anti-inflammatory drug (NSAID) use (45 versus 71; p = 0.07). There were no demographic differences between groups in patients with secondary fractures. Nonoperative treatment was identified as a statistically significant independent risk factor for subsequent vertebral compression fracture [odds ratio (OR), 2.28]. Univariate

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

    PubMed

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

    2013-10-01

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

  16. Low-level night-time light therapy for age-related macular degeneration (ALight): study protocol for a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Age-related macular degeneration (AMD) is the leading cause of blindness among older adults in the developed world. The only treatments currently available, such as ranibizumab injections, are for neovascular AMD, which accounts for only 10 to 15% of people with the condition. Hypoxia has been implicated as one of the primary causes of AMD, and is most acute at night when the retina is most metabolically active. By increasing light levels at night, the metabolic requirements of the retina and hence the hypoxia will be considerably reduced. This trial seeks to determine whether wearing a light mask that emits a dim, green light during the night can prevent the progression of early AMD. Methods/design ALight is a Phase I/IIa, multicentre, randomized controlled trial. Sixty participants (55 to 88 years old) with early AMD in one eye and neovascular AMD (nAMD) in the fellow eye will be recruited from nAMD clinics. They will be randomized (in the ratio 1:1), either to receive the intervention or to be in the untreated control group, stratified according to risk of disease progression. An additional 40 participants with healthy retinal appearance, or early AMD only, will be recruited for a baseline cross-sectional analysis. The intervention is an eye mask that emits a dim green light to illuminate the retina through closed eyelids at night. This is designed to reduce the metabolic activity of the retina, thereby reducing the potential risk of hypoxia. Participants will wear the mask every night for 12 months. Ophthalmologists carrying out monthly assessments will be masked to the treatment group, but participants will be aware of their treatment group. The primary outcome measure is the proportion of people who show disease progression during the trial period in the eye with early AMD. A co-primary outcome measure is the rate of retinal adaptation. As this is a trial of a CE-marked device for an off-label indication, a further main aim of this trial is to

  17. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2014

    USGS Publications Warehouse

    Beman, Joseph E.

    2015-10-21

    An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. The network currently (2014) consists of 125 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority, currently (2014) measures and reports water levels from the 125 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 125 sites through water year 2014 (October 1, 2013, to September 30, 2014).

  18. Pellucid marginal corneal degeneration.

    PubMed

    Krachmer, J H

    1978-07-01

    Pellucid marginal degeneration of the cornea is a bilateral, clear, inferior, peripheral corneal-thinning disorder. Protrusion of the cornea occurs above a band of thinning, which is located 1 to 2 mm from the limbus and measures 1 to 2 mm in width. American ophthalmologists are generally not familiar with the condition because most of the literature concerning pellucid degeneration is European. Four cases are described. This condition is differentiated from other noninflammatory cornel-thinning disorders such as keratoconus, keratoglobus, keratotorus, and posterior keratoconus. It is also differentiated from peripheral corneal disorders associated with inflammation such as Terrien's peripheral corneal degeneration, Mooren's ulcers, and ulcers from connective tissue disease.

  19. Geologic and hydrologic data collected during 1976-1983 at the Sheffield low-level radioactive waste disposal site and adjacent areas, Sheffield, Illinois

    USGS Publications Warehouse

    Foster, J.B.; Garklavs, George; Mackey, G.W.

    1984-01-01

    Hydrogeologic studies were conducted at the low-level radioactive-waste disposal site near Sheffield, Illinois, from 1976-84. Data in this report include water levels in wells, lake stages, inorganic, organic, and radiometric chemical analyses of ground and surface water, hydraulic conductivities of glacial materials, grain-size distribution, clay and carbonate mineralogy, and cation exchange capacities of the glacial materials. Also included are results of petrographic analyses, physical measurements of wells, stratigraphy and lithology of cores collected from test wells, and horizontal coordinates of wells.

  20. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2012

    USGS Publications Warehouse

    Beman, Joseph E.

    2013-01-01

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25-40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. A population increase of about 20 percent in the basin from 1990 to 2000 and a 22 percent increase from 2000 to 2010 resulted in an increased demand for water. An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2012), the network consists of 126 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority (ABCWUA), currently (2012) measures and reports water levels from the 126 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 126 sites through water year 2012.

  1. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2013

    USGS Publications Warehouse

    Beman, Joseph E.

    2014-01-01

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when treatment and distribution of surface water from the Rio Grande began. A population increase of about 20 percent in the basin from 1990 to 2000 and a 22-percent increase from 2000 to 2010 resulted in an increased demand for water. An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2013), the network consists of 123 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the Albuquerque Bernalillo County Water Utility Authority, currently (2013) measures and reports water levels from the 123 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 123 sites through water year 2013.

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

    PubMed Central

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

    2016-01-01

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

  3. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2015

    USGS Publications Warehouse

    Beman, Joseph E.; Bryant, Christina F.

    2016-10-27

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is hydrologically defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift between San Acacia to the south and Cochiti Lake to the north. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when the Albuquerque Bernalillo County Water Utility Authority (ABCWUA) began treatment and distribution of surface water from the Rio Grande through the San Juan-Chama Drinking Water Project. A 20-percent population increase in the basin from 1990 to 2000 and a 22-percent population increase from 2000 to 2010 may have resulted in an increased demand for water in areas within the basin.An initial network of wells was established by the U.S. Geological Survey (USGS) in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the Albuquerque Basin. In 1983, this network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly. The network currently (2015) consists of 124 wells and piezometers. (A piezometer is a specialized well open to a specific depth in the aquifer, often of small diameter and nested with other piezometers open to different depths.) The USGS, in cooperation with the ABCWUA, currently (2015) measures and reports water levels from the 124 wells and piezometers in the network; this report presents water-level data collected by USGS personnel at those 124 sites through water year 2015 (October 1, 2014, through September 30, 2015).

  4. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2009

    USGS Publications Warehouse

    Beman, Joseph E.; Torres, Leeanna T.

    2010-01-01

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. A network of wells was established to monitor changes in groundwater levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2009), the network consists of 131 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 123 sites through water year 2009. In addition, data from four wells (Sites 140, 147, 148, and 149) owned, maintained, and measured by Sandia National Laboratories and three from Kirtland Air Force Base (Sites 119, 125, and 126) are presented in this report.

  5. Water-Level Data for the Albuquerque Basin and Adjacent Areas, Central New Mexico, Period of Record Through September 30, 2008

    USGS Publications Warehouse

    Beman, Joseph E.

    2009-01-01

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25 to 40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompass the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin are currently (2008) obtained soley from ground-water resources. An increase of about 20 percent in the population from 1990 to 2000 also resulted in an increased demand for water. A network of wells was established to monitor changes in ground-water levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2008), the network consists of 144 wells and piezometers. This report presents water-level data collected by U.S. Geological Survey personnel at 125 sites through water-year 2008. In addition, data from 19 wells (Sites 127-30, 132-134, 136, 138-142 and 144-149) owned, maintained, and measured by Sandia National Laboratories are presented in this report.

  6. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2010

    USGS Publications Warehouse

    Beman, Joseph E.

    2011-01-01

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25-40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the basin human population from 1990 to 2000 and about a 22 percent increase from 2000 to 2010 also resulted in an increased demand for water. A network of wells was established by the U.S. Geological Survey in cooperation with the City of Albuquerque to monitor changes in groundwater levels throughout the basin from April 1982 through September 1983. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2010), the network consists of 124 wells and piezometers (a piezometer is a small-diameter subwell usually nested within a larger well). To better help the Albuquerque Bernalillo County Water Utility Authority manage water use, this report presents water-level data collected by U.S. Geological Survey personnel at those 124 sites through water year 2010.

  7. Water-level data for the Albuquerque Basin and adjacent areas, central New Mexico, period of record through September 30, 2011

    USGS Publications Warehouse

    Beman, Joseph E.

    2012-01-01

    The Albuquerque Basin, located in central New Mexico, is about 100 miles long and 25–40 miles wide. The basin is defined as the extent of consolidated and unconsolidated deposits of Tertiary and Quaternary age that encompasses the structural Rio Grande Rift within the basin. Drinking-water supplies throughout the basin were obtained solely from groundwater resources until December 2008, when surface water from the Rio Grande began being treated and integrated into the system. An increase of about 20 percent in the basin human population from 1990 to 2000 and of about 22 percent increase from 2000 to 2010 also resulted in an increased demand for water. A network of wells was established by the U.S. Geological Survey in cooperation with the City of Albuquerque from April 1982 through September 1983 to monitor changes in groundwater levels throughout the basin. This network consisted of 6 wells with analog-to-digital recorders and 27 wells where water levels were measured monthly in 1983. Currently (2011), the network consists of 126 wells and piezometers (a piezometer is a specialized well open to a specific depth in the aquifer and is often of small diameter and nested with other piezometers open to different depths). This report presents water-level data collected by U.S. Geological Survey personnel at those 126 sites through water year 2011 to better help the Albuquerque Bernalillo County Water Utility Authority manage water use.

  8. Double Degenerate Binary Systems

    SciTech Connect

    Yakut, K.

    2011-09-21

    In this study, angular momentum loss via gravitational radiation in double degenerate binary (DDB)systems (NS + NS, NS + WD, WD + WD, and AM CVn) is studied. Energy loss by gravitational waves has been estimated for each type of systems.

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

    PubMed

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

    2017-01-01

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

  10. Temperature variations at nano-scale level in phase transformed nanocrystalline NiTi shape memory alloys adjacent to graphene layers.

    PubMed

    Amini, Abbas; Cheng, Chun; Naebe, Minoo; Church, Jeffrey S; Hameed, Nishar; Asgari, Alireza; Will, Frank

    2013-07-21

    The detection and control of the temperature variation at the nano-scale level of thermo-mechanical materials during a compression process have been challenging issues. In this paper, an empirical method is proposed to predict the temperature at the nano-scale level during the solid-state phase transition phenomenon in NiTi shape memory alloys. Isothermal data was used as a reference to determine the temperature change at different loading rates. The temperature of the phase transformed zone underneath the tip increased by ∼3 to 40 °C as the loading rate increased. The temperature approached a constant with further increase in indentation depth. A few layers of graphene were used to enhance the cooling process at different loading rates. Due to the presence of graphene layers the temperature beneath the tip decreased by a further ∼3 to 10 °C depending on the loading rate. Compared with highly polished NiTi, deeper indentation depths were also observed during the solid-state phase transition, especially at the rate dependent zones. Larger superelastic deformations confirmed that the latent heat transfer through the deposited graphene layers allowed a larger phase transition volume and, therefore, more stress relaxation and penetration depth.

  11. Selected metal levels of commercially valuable seaweeds adjacent to and distant from point sources of contamination in Nova Scotia and New Brunswick

    SciTech Connect

    Sharp, G.J. ); Samant, H.S.; Vaidya, O.C. )

    1988-06-01

    The harvesting of marine plants on a commercial scale was a significant industry in the Maritime Provinces of Canada by the end of World War II. These seaweeds have been traditionally utilized as foodstuffs either as a processed extract or a semi-processed plant. The Maritime coastline is becoming industrialized; there is also potential for expansion of the marine plant industry beyond traditional harvest areas. Therefore, the quality of material from new areas must be examined prior to exploitation as well as monitoring of traditional areas. The bioaccumulated of metals by marine plants was recognized in early measurements of trace element concentrations which were above ambient water values. Before growth and reproductive inhibition are caused by severe effects of heavy metal pollution, food quality changes may occur. The Food Chemical Code (U.S.A.) limits heavy metals in the extracts of seaweeds. Sediment and water samples taken in connection with the Ocean Dumping Control Act of Canada have identified several sites with elevated heavy metal content in the Maritimes. The purpose of this study was to examine heavy metal levels in commercially important seaweeds from traditional harvest areas and areas near point sources of pollution. The authors wished to provide a baseline for the future and identify existing problem areas.

  12. Potential effects of groundwater pumping on water levels, phreatophytes, and spring discharges in Spring and Snake Valleys, White Pine County, Nevada, and adjacent areas in Nevada and Utah

    USGS Publications Warehouse

    Halford, Keith J.; Plume, Russell W.

    2011-01-01

    Assessing hydrologic effects of developing groundwater supplies in Snake Valley required numerical, groundwater-flow models to estimate the timing and magnitude of capture from streams, springs, wetlands, and phreatophytes. Estimating general water-table decline also required groundwater simulation. The hydraulic conductivity of basin fill and transmissivity of basement-rock distributions in Spring and Snake Valleys were refined by calibrating a steady state, three-dimensional, MODFLOW model of the carbonate-rock province to predevelopment conditions. Hydraulic properties and boundary conditions were defined primarily from the Regional Aquifer-System Analysis (RASA) model except in Spring and Snake Valleys. This locally refined model was referred to as the Great Basin National Park calibration (GBNP-C) model. Groundwater discharges from phreatophyte areas and springs in Spring and Snake Valleys were simulated as specified discharges in the GBNP-C model. These discharges equaled mapped rates and measured discharges, respectively. Recharge, hydraulic conductivity, and transmissivity were distributed throughout Spring and Snake Valleys with pilot points and interpolated to model cells with kriging in geologically similar areas. Transmissivity of the basement rocks was estimated because thickness is correlated poorly with transmissivity. Transmissivity estimates were constrained by aquifer-test results in basin-fill and carbonate-rock aquifers. Recharge, hydraulic conductivity, and transmissivity distributions of the GBNP-C model were estimated by minimizing a weighted composite, sum-of-squares objective function that included measurement and Tikhonov regularization observations. Tikhonov regularization observations were equations that defined preferred relations between the pilot points. Measured water levels, water levels that were simulated with RASA, depth-to-water beneath distributed groundwater and spring discharges, land-surface altitudes, spring discharge at

  13. Striatal degeneration in childhood.

    PubMed Central

    Erdohazi, M; Marshall, P

    1979-01-01

    The clinical features, and the radiological and neuropathological findings of 3 unrelated children with striatal degeneration are presented. In one case the father had recently developed choreiform movements while in the other two the family history was negative for neurological disorders. Two patients had juvenile onset of psychiatric symptoms, seizures, and rigidity. The 3rd child presented with focal seizures at 9 weeks of age. The neuropathological findings are virtually identical in all 3 cases. The classification of striatal degeneration in childhood is discussed. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 PMID:434899

  14. Kraepelin and degeneration theory.

    PubMed

    Hoff, Paul

    2008-06-01

    Emil Kraepelin's contribution to the clinical and scientific field of psychiatry is recognized world-wide. In recent years, however, there have been a number of critical remarks on his acceptance of degeneration theory in particular and on his political opinion in general, which was said to have carried "overtones of proto-fascism" by Michael Shepherd [28]. The present paper discusses the theoretical cornerstones of Kraepelinian psychiatry with regard to their relevance for Kraepelin's attitude towards degeneration theory. This theory had gained wide influence not only in scientific, but also in philosophical and political circles in the last decades of the nineteenth century. There is no doubt that Kraepelin, on the one hand, accepted and implemented degeneration theory into the debate on etiology and pathogenesis of mental disorders. On the other hand, it is not appropriate to draw a simple and direct line from early versions of degeneration theory to the crimes of psychiatrists and politicians during the rule of national socialism. What we need, is a differentiated view, since this will be the only scientific one. Much research needs to be done here in the future, and such research will surely have a significant impact not only on the historical field, but also on the continuous debate about psychiatry, neuroscience and neurophilosophy.

  15. Frontotemporal Lobar Degeneration

    PubMed Central

    Josephs, Keith A.

    2009-01-01

    Synopsis Frontotemporal lobar degeneration (FTLD) is a syndromic diagnosis that encompasses at least three different variants. Imaging modalities are clinically useful in FTLD while pathology remains the gold standard for definitive diagnosis. To date three different genes have been identified that account for FTLD. PMID:17659185

  16. X-82 to Treat Age-related Macular Degeneration

    ClinicalTrials.gov

    2017-01-12

    Age-Related Macular Degeneration (AMD); Macular Degeneration; Exudative Age-related Macular Degeneration; AMD; Macular Degeneration, Age-related, 10; Eye Diseases; Retinal Degeneration; Retinal Diseases

  17. Comparison of Cerebrospinal Fluid Levels of Tau and Aß1-42 in Alzheimer’s disease and Frontotemporal Degeneration Using Two Analytical Platforms

    PubMed Central

    Irwin, David J.; McMillan, Corey T.; Toledo, Jon B.; Arnold, Steven E.; Shaw, Leslie M.; Wang, Li-San; Lee, Virginia M.-Y.; Trojanowski, John Q.; Grossman, Murray

    2012-01-01

    Objective To utilize values of cerebrospinal fluid (CSF) tau and ß-amyloid obtained from two different analytical immunoassays to differentiate Alzheimer’s disease (AD) from frontotemporal lobar degeneration (FTLD). Design CSF values of total tau (t-tau) and ß-amyloid (Aß1-42) obtained using the INNOTEST® ELISA were transformed using a linear regression model to equivalent values obtained using the INNO-BIA AlzBio3™ (xMAP Luminex) assay. Cutoff values obtained from the xMAP assay were developed in a series of autopsy-confirmed cases and cross-validated in another series of autopsy-confirmed samples using transformed ELISA values to assess sensitivity and specificity for differentiating AD from FTLD. Setting Tertiary memory disorders clinics and neuropathological and biomarker core centers. Participants 75 samples from patients with CSF data obtained from both assays were used for transformation of ELISA values. 40 autopsy-confirmed cases (30 AD, 10 FTLD) were used to establish diagnostic cutoff values, and then cross-validated in a second sample set of 21 autopsy-confirmed cases (11 AD, 10 FTLD) with transformed ELISA values. Main outcome measure Diagnostic accuracy using transformed biomarker values. Results Data obtained from both assays were highly correlated. The t-tau:Aß1-42 ratio had the highest correlation between measures (r=0.928, p<0.001) and high reliability of transformation (ICC=0.89). A cutoff of 0.34 for the t-tau:Aß1-42 ratio had 90% and 100% sensitivity and 96.7% and 91% specificity to differentiate FTLD cases in the validation and cross-validation samples, respectively. Conclusions Values from two analytical platforms can be transformed into equivalent units, which can distinguish AD from FTLD more accurately than the clinical diagnosis. PMID:22490326

  18. Frontotemporal Lobar Degeneration

    PubMed Central

    Rabinovici, Gil D.; Miller, Bruce L.

    2010-01-01

    Frontotemporal lobar degeneration (FTLD) is a clinically and pathologically heterogeneous syndrome, characterized by progressive decline in behaviour or language associated with degeneration of the frontal and anterior temporal lobes. While the seminal cases were described at the turn of the 20th century, FTLD has only recently been appreciated as a leading cause of dementia, particularly in patients presenting before the age of 65 years. Three distinct clinical variants of FTLD have been described: (i) behavioural-variant frontotemporal dementia, characterized by changes in behaviour and personality in association with frontal-predominant cortical degeneration; (ii) semantic dementia, a syndrome of progressive loss of knowledge about words and objects associated with anterior temporal neuronal loss; and (iii) progressive nonfluent aphasia, characterized by effortful language output, loss of grammar and motor speech deficits in the setting of left perisylvian cortical atrophy. The majority of pathologies associated with FTLD clinical syndromes include either tau-positive (FTLD-TAU) or TAR DNA-binding protein 43 (TDP-43)-positive (FTLD-TDP) inclusion bodies. FTLD overlaps clinically and pathologically with the atypical parkinsonian disorders corticobasal degeneration and progressive supranuclear palsy, and with amyotrophic lateral sclerosis. The majority of familial FTLD cases are caused by mutations in the genes encoding microtubule-associated protein tau (leading to FTLD-TAU) or progranulin (leading to FTLD-TDP). The clinical and pathologic heterogeneity of FTLD poses a significant diagnostic challenge, and in vivo prediction of underlying histopathology can be significantly improved by supplementing the clinical evaluation with genetic tests and emerging biological markers. Current pharmacotherapy for FTLD focuses on manipulating serotonergic or dopaminergic neurotransmitter systems to ameliorate behavioural or motor symptoms. However, recent advances in FTLD

  19. Cataracts and macular degeneration.

    PubMed

    Shoch, D

    1979-09-01

    The intraocular lens restores general vision and some degree of independence and mobility to patients with dense cataracts and macular degeneration. The patient, however, must be repeatedly warned that fine central vision, particularly reading, will not be possible after the surgery. An aphakic spectacle leaves such patients a narrow band of vision when superimposed over the macular lesion, and contact lenses are too small for the patient to manage insertion without help.

  20. Prospectives for Gene Therapy of Retinal Degenerations

    PubMed Central

    Thumann, Gabriele

    2012-01-01

    Retinal degenerations encompass a large number of diseases in which the retina and associated retinal pigment epithelial (RPE) cells progressively degenerate leading to severe visual disorders or blindness. Retinal degenerations can be divided into two groups, a group in which the defect has been linked to a specific gene and a second group that has a complex etiology that includes environmental and genetic influences. The first group encompasses a number of relatively rare diseases with the most prevalent being Retinitis pigmentosa that affects approximately 1 million individuals worldwide. Attempts have been made to correct the defective gene by transfecting the appropriate cells with the wild-type gene and while these attempts have been successful in animal models, human gene therapy for these inherited retinal degenerations has only begun recently and the results are promising. To the second group belong glaucoma, age-related macular degeneration (AMD) and diabetic retinopathy (DR). These retinal degenerations have a genetic component since they occur more often in families with affected probands but they are also linked to environmental factors, specifically elevated intraocular pressure, age and high blood sugar levels respectively. The economic and medical impact of these three diseases can be assessed by the number of individuals affected; AMD affects over 30 million, DR over 40 million and glaucoma over 65 million individuals worldwide. The basic defect in these diseases appears to be the relative lack of a neurogenic environment; the neovascularization that often accompanies these diseases has suggested that a decrease in pigment epithelium-derived factor (PEDF), at least in part, may be responsible for the neurodegeneration since PEDF is not only an effective neurogenic and neuroprotective agent but also a potent inhibitor of neovascularization. In the last few years inhibitors of vascularization, especially antibodies against vascular endothelial cell

  1. A painful neuropathy-associated Nav1.7 mutant leads to time-dependent degeneration of small-diameter axons associated with intracellular Ca2+ dysregulation and decrease in ATP levels.

    PubMed

    Rolyan, Harshvardhan; Liu, Shujun; Hoeijmakers, Janneke Gj; Faber, Catharina G; Merkies, Ingemar Sj; Lauria, Giuseppe; Black, Joel A; Waxman, Stephen G

    2016-01-01

    Small fiber neuropathy is a painful sensory nervous system disorder characterized by damage to unmyelinated C- and thinly myelinated Aδ- nerve fibers, clinically manifested by burning pain in the distal extremities and dysautonomia. The clinical onset in adulthood suggests a time-dependent process. The mechanisms that underlie nerve fiber injury in small fiber neuropathy are incompletely understood, although roles for energetic stress have been suggested. In the present study, we report time-dependent degeneration of neurites from dorsal root ganglia neurons in culture expressing small fiber neuropathy-associated G856D mutant Nav1.7 channels and demonstrate a time-dependent increase in intracellular calcium levels [Ca(2+)]i and reactive oxygen species, together with a decrease in ATP levels. Together with a previous clinical report of burning pain in the feet and hands associated with reduced levels of Na(+)/K(+)-ATPase in humans with high altitude sickness, the present results link energetic stress and reactive oxygen species production with the development of a painful neuropathy that preferentially affects small-diameter axons.

  2. A painful neuropathy-associated Nav1.7 mutant leads to time-dependent degeneration of small-diameter axons associated with intracellular Ca2+ dysregulation and decrease in ATP levels

    PubMed Central

    Rolyan, Harshvardhan; Liu, Shujun; Hoeijmakers, Janneke GJ; Faber, Catharina G; Merkies, Ingemar SJ; Lauria, Giuseppe; Black, Joel A

    2016-01-01

    Small fiber neuropathy is a painful sensory nervous system disorder characterized by damage to unmyelinated C- and thinly myelinated Aδ- nerve fibers, clinically manifested by burning pain in the distal extremities and dysautonomia. The clinical onset in adulthood suggests a time-dependent process. The mechanisms that underlie nerve fiber injury in small fiber neuropathy are incompletely understood, although roles for energetic stress have been suggested. In the present study, we report time-dependent degeneration of neurites from dorsal root ganglia neurons in culture expressing small fiber neuropathy-associated G856D mutant Nav1.7 channels and demonstrate a time-dependent increase in intracellular calcium levels [Ca2+]i and reactive oxygen species, together with a decrease in ATP levels. Together with a previous clinical report of burning pain in the feet and hands associated with reduced levels of Na+/K+-ATPase in humans with high altitude sickness, the present results link energetic stress and reactive oxygen species production with the development of a painful neuropathy that preferentially affects small-diameter axons. PMID:27821467

  3. Two Ultracool Degenerate Companions

    NASA Astrophysics Data System (ADS)

    Farihi, J.

    2005-07-01

    In the course of an extensive survey for low mass stellar and substellar companions to nearby white dwarfs, two extrememly cool degenerate objects have been discovered. GD 392B is one of only a few known white dwarfs with Teff⪉4000 K and exhibits collision induced absorption in the near infrared tep{far04}. GD 1400B is the second known L dwarf companion to a white dwarf and a possible brown dwarf (Farihi & Christopher 2004). Interested readers should consult the references for a complete description of these two cool objects.

  4. Progranulin Knockout Accelerates Intervertebral Disc Degeneration in Aging Mice

    PubMed Central

    Zhao, Yun-peng; Tian, Qing-yun; Liu, Ben; Cuellar, Jason; Richbourgh, Brendon; Jia, Tang-hong; Liu, Chuan-ju

    2015-01-01

    Intervertebral disc (IVD) degeneration is a common degenerative disease, yet much is unknown about the mechanisms during its pathogenesis. Herein we investigated whether progranulin (PGRN), a chondroprotective growth factor, is associated with IVD degeneration. PGRN was detectable in both human and murine IVD. The levels of PGRN were upregulated in murine IVD tissue during aging process. Loss of PGRN resulted in an early onset of degenerative changes in the IVD tissue and altered expressions of the degeneration-associated molecules in the mouse IVD tissue. Moreover, PGRN knockout mice exhibited accelerated IVD matrix degeneration, abnormal bone formation and exaggerated bone resorption in vertebra with aging. The acceleration of IVD degeneration observed in PGRN null mice was probably due to the enhanced activation of NF-κB signaling and β-catenin signaling. Taken together, PGRN may play a critical role in homeostasis of IVD, and may serve as a potential molecular target for prevention and treatment of disc degenerative diseases. PMID:25777988

  5. Radiologic Evaluation of Degeneration in Isthmic and Degenerative Spondylolisthesis

    PubMed Central

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

    2013-01-01

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

  6. What Is Age-Related Macular Degeneration?

    MedlinePlus

    ... of Low Vision Age-Related Macular Degeneration Vision Simulator AMD Pictures and Videos: What Does Macular Degeneration ... degeneration as part of the body's natural aging process. There are different kinds of macular problems, but ...

  7. Genetics Home Reference: Stargardt macular degeneration

    MedlinePlus

    ... Genetics Home Health Conditions Stargardt macular degeneration Stargardt macular degeneration Enable Javascript to view the expand/collapse boxes. Download PDF Open All Close All Description Stargardt macular degeneration is a genetic eye disorder that causes progressive ...

  8. Evaluation of Fluoro-Jade C as a marker of degenerating neurons in the rat retina and optic nerve.

    PubMed

    Chidlow, Glyn; Wood, John P M; Sarvestani, Ghafar; Manavis, Jim; Casson, Robert J

    2009-03-01

    Detection of neuronal death is an essential requirement for researchers investigating retinal degeneration. Fluoro-Jade C (FJC) is a novel, fluorescent dye that has been successfully used to label degenerating neurons in the brain, but its effectiveness in the eye has not been ascertained. In the current study, we determined the efficacy of FJC for detection of neuronal degeneration in the retina and optic nerve in various paradigms of injury. N-methyl-D-aspartate (NMDA) and kainic acid-induced excitotoxicity, optic nerve transection, and bilateral occlusion of the common carotid arteries (BCCAO) were performed using standard techniques. Rats were killed at various time points and the retinas with optic nerves attached were removed for tissue processing prior to labelling for FJC, for DNA fragmentation by TUNEL or for immunohistochemical analysis. Retinas from RCS rats of different ages were also analysed. After excitotoxicity-induced injury, cell bodies and dendrites within the ganglion cell and inner plexiform layers were specifically labelled by FJC within 6h, a time point comparable to the appearance of TUNEL-positive nuclei and to reductions in mRNA levels of retinal ganglion cell-specific proteins, but in advance of alterations in some immunohistochemical markers. The number of FJC-labelled cell bodies in the retina declined over time as cell loss proceeded, although dendritic staining remained prominent. Colocalisation of FJC with TUNEL and with immunohistochemical neuronal markers was achieved. FJC was successful at identifying somato-dendritic degeneration following ischemia induced by BCCAO, but surprisingly, not after optic nerve transection. FJC visualised photoreceptor degeneration in the RCS rat, albeit less effectively than with the TUNEL assay, and was also effective for imaging and quantifying degenerating axons in the optic nerve after multiple injuries. In addition to labelling degenerating neurons, however, FJC also bound non-specifically to

  9. Recombination-generation currents in degenerate semiconductors

    NASA Technical Reports Server (NTRS)

    Von Roos, O.

    1978-01-01

    The classical Shockley-Read-Hall theory of free carrier recombination and generation via traps is extended to degenerate semiconductors. A concise and simple expression is found which avoids completely the concept of a Fermi level, a concept which is alien to nonequilibrium situations. Assumptions made in deriving the recombination generation current are carefully delineated and are found to be basically identical to those made in the original theory applicable to nondegenerate semiconductors.

  10. [Age related macular degeneration].

    PubMed

    Sayen, Alexandra; Hubert, Isabelle; Berrod, Jean-Paul

    2011-02-01

    Age-related macular degeneration (ARMD) is a multifactorial disease caused by a combination of genetic and environmental factors. It is the first cause of blindness in patients over 50 in the western world. The disease has been traditionally classified into early and late stages with dry (atrophic) and wet (neovascular) forms: neovascular form is characterized by new blood vessels development under the macula (choroidal neovascularisation) which lead to a rapid decline of vision associated with metamorphopsia and requiring an urgent ophtalmological examination. Optical coherence tomography is now one of the most important part of the examination for diagnosis and treatment. Patient with age related maculopathy should consider taking a dietary supplement such that used in AREDS. The treatment of the wet ARMD has largely beneficied since year 2006 of anti-VEGF (vascular endothelial growth factor) molecules such as ranibizumab or bevacizumab given as repeated intravitreal injections. A systematic follow up each 4 to 8 week in required for several years. There is no effective treatment at the moment for dry AMD. For patients with binocular visual acuity under 60/200 rehabilitation includes low vision specialist, vision aids and psychological support.

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

    PubMed

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

    2016-01-01

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

  12. Early stage disc degeneration does not have an appreciable affect on stiffness and load transfer following vertebroplasty and kyphoplasty

    PubMed Central

    Keller, Tony S.; Schizas, Constantin

    2008-01-01

    Vertebroplasty and kyphoplasty have been reported to alter the mechanical behavior of the treated and adjacent-level segments, and have been suggested to increase the risk for adjacent-level fractures. The intervertebral disc (IVD) plays an important role in the mechanical behavior of vertebral motion segments. Comparisons between normal and degenerative IVD motion segments following cement augmentation have yet to be reported. A microstructural finite element model of a degenerative IVD motion segment was constructed from micro-CT images. Microdamage within the vertebral body trabecular structure was used to simulate a slightly (I = 83.5% of intact stiffness), moderately (II = 57.8% of intact stiffness), and severely (III = 16.0% of intact stiffness) damaged motion segment. Six variable geometry single-segment cement repair strategies (models A–F) were studied at each damage level (I–III). IVD and bone stresses, and motion segment stiffness, were compared with the intact and baseline damage models (untreated), as well as, previous findings using normal IVD models with the same repair strategies. Overall, small differences were observed in motion segment stiffness and average stresses between the degenerative and normal disc repair models. We did however observe a reduction in endplate bulge and a redistribution in the microstructural tissue level stresses across both endplates and in the treated segment following early stage IVD degeneration. The cement augmentation strategy placing bone cement along the periphery of the vertebra (model E) proved to be the most advantageous in treating the degenerative IVD models by showing larger reductions in the average bone stresses (vertebral and endplate) as compared to the normal IVD models. Furthermore, only this repair strategy, and the complete cement fill strategy (model F), were able to restore the slightly damaged (I) motion segment stiffness above pre-damaged (intact) levels. Early stage IVD degeneration

  13. Age-Related Macular Degeneration

    MedlinePlus

    ... version of this page please turn Javascript on. Age-related Macular Degeneration About AMD Click for more ... a leading cause of vision loss among people age 60 and older. It causes damage to the ...

  14. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  15. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  16. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  17. 46 CFR 148.445 - Adjacent spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  18. Age-related macular degeneration.

    PubMed

    Lim, Laurence S; Mitchell, Paul; Seddon, Johanna M; Holz, Frank G; Wong, Tien Y

    2012-05-05

    Age-related macular degeneration is a major cause of blindness worldwide. With ageing populations in many countries, more than 20% might have the disorder. Advanced age-related macular degeneration, including neovascular age-related macular degeneration (wet) and geographic atrophy (late dry), is associated with substantial, progressive visual impairment. Major risk factors include cigarette smoking, nutritional factors, cardiovascular diseases, and genetic markers, including genes regulating complement, lipid, angiogenic, and extracellular matrix pathways. Some studies have suggested a declining prevalence of age-related macular degeneration, perhaps due to reduced exposure to modifiable risk factors. Accurate diagnosis combines clinical examination and investigations, including retinal photography, angiography, and optical coherence tomography. Dietary anti-oxidant supplementation slows progression of the disease. Treatment for neovascular age-related macular degeneration incorporates intraocular injections of anti-VEGF agents, occasionally combined with other modalities. Evidence suggests that two commonly used anti-VEGF therapies, ranibizumab and bevacizumab, have similar efficacy, but possible differences in systemic safety are difficult to assess. Future treatments include inhibition of other angiogenic factors, and regenerative and topical therapies.

  19. MRI evaluation of spontaneous intervertebral disc degeneration in the alpaca cervical spine.

    PubMed

    Stolworthy, Dean K; Bowden, Anton E; Roeder, Beverly L; Robinson, Todd F; Holland, Jacob G; Christensen, S Loyd; Beatty, Amanda M; Bridgewater, Laura C; Eggett, Dennis L; Wendel, John D; Stieger-Vanegas, Susanne M; Taylor, Meredith D

    2015-12-01

    Animal models have historically provided an appropriate benchmark for understanding human pathology, treatment, and healing, but few animals are known to naturally develop intervertebral disc degeneration. The study of degenerative disc disease and its treatment would greatly benefit from a more comprehensive, and comparable animal model. Alpacas have recently been presented as a potential large animal model of intervertebral disc degeneration due to similarities in spinal posture, disc size, biomechanical flexibility, and natural disc pathology. This research further investigated alpacas by determining the prevalence of intervertebral disc degeneration among an aging alpaca population. Twenty healthy female alpacas comprised two age subgroups (5 young: 2-6 years; and 15 older: 10+ years) and were rated according to the Pfirrmann-grade for degeneration of the cervical intervertebral discs. Incidence rates of degeneration showed strong correlations with age and spinal level: younger alpacas were nearly immune to developing disc degeneration, and in older animals, disc degeneration had an increased incidence rate and severity at lower cervical levels. Advanced disc degeneration was present in at least one of the cervical intervertebral discs of 47% of the older alpacas, and it was most common at the two lowest cervical intervertebral discs. The prevalence of intervertebral disc degeneration encourages further investigation and application of the lower cervical spine of alpacas and similar camelids as a large animal model of intervertebral disc degeneration.

  20. Seismicity in Azerbaijan and Adjacent Caspian Sea

    SciTech Connect

    Panahi, Behrouz M.

    2006-03-23

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

  1. Age-Related Macular Degeneration.

    PubMed

    Mehta, Sonia

    2015-09-01

    Age-related macular degeneration (AMD) is the leading cause of vision loss in the elderly. AMD is diagnosed based on characteristic retinal findings in individuals older than 50. Early detection and treatment are critical in increasing the likelihood of retaining good and functional vision.

  2. Reconstitution of degenerated ovine lumbar discs by STRO-3-positive allogeneic mesenchymal precursor cells combined with pentosan polysulfate.

    PubMed

    Oehme, David; Ghosh, Peter; Goldschlager, Tony; Itescu, Silviu; Shimon, Susan; Wu, Jiehua; McDonald, Courtney; Troupis, John M; Rosenfeld, Jeffrey V; Jenkin, Graham

    2016-05-01

    OBJECTIVE Disc degeneration and associated low-back pain are major causes of suffering and disability. The authors examined the potential of mesenchymal precursor cells (MPCs), when formulated with pentosan polysulfate (PPS), to ameliorate disc degeneration in an ovine model. METHODS Twenty-four sheep had annular incisions made at L2-3, L3-4, and L4-5 to induce degeneration. Twelve weeks after injury, the nucleus pulposus of a degenerated disc in each animal was injected with ProFreeze and PPS formulated with either a low dose (0.1 million MPCs) or a high dose (0.5 million MPCs) of cells. The 2 adjacent injured discs in each spine were either injected with PPS and ProFreeze (PPS control) or not injected (nil-injected control). The adjacent noninjured L1-2 and L5-6 discs served as noninjured control discs. Disc height indices (DHIs) were obtained at baseline, before injection, and at planned death. After necropsy, 24 weeks after injection, the spines were subjected to MRI and morphological, histological, and biochemical analyses. RESULTS Twelve weeks after the annular injury, all the injured discs exhibited a significant reduction in mean DHI (low-dose group 17.19%; high-dose group 18.01% [p < 0.01]). Twenty-four weeks after injections, the discs injected with the low-dose MPC+PPS formulation recovered disc height, and their mean DHI was significantly greater than the DHI of PPS- and nil-injected discs (p < 0.001). Although the mean Pfirrmann MRI disc degeneration score for the low-dose MPC+PPS-injected discs was lower than that for the nil- and PPS-injected discs, the differences were not significant. The disc morphology scores for the nil- and PPS-injected discs were significantly higher than the normal control disc scores (p < 0.005), whereas the low-dose MPC+PPS-injected disc scores were not significantly different from those of the normal controls. The mean glycosaminoglycan content of the nuclei pulposus of the low-dose MPC+PPS-injected discs was significantly

  3. Lumbar intervertebral disc degeneration and related factors in Korean firefighters

    PubMed Central

    Jang, Tae-Won; Ahn, Yeon-Soon; Byun, Junsu; Lee, Jong-In; Kim, Kun-Hyung; Kim, Youngki; Song, Han-Soo; Lee, Chul-Gab; Kwon, Young-Jun; Yoon, Jin-Ha; Jeong, Kyoungsook

    2016-01-01

    Objectives The job of firefighting can cause lumbar burden and low back pain. This study aimed to identify the association between age and lumbar intervertebral disc degeneration and whether the association differs between field and administrative (non-field) firefighters. Methods Subjects were selected using a stratified random sampling method. Firefighters were stratified by geographic area, gender, age and type of job. First, 25 fire stations were randomly sampled considering regional distribution. Then firefighters were stratified by gender, age and their job and randomly selected among the strata. A questionnaire survey and MRI scans were performed, and then four radiologists used Pfirrmann classification methods to determine the grade of lumbar intervertebral disc degeneration. Results Pfirrmann grade increased with lumbar intervertebral disc level. Analysis of covariance showed that age was significantly associated with lumbar intervertebral disc degeneration (p<0.05). The value of β (parameter estimate) was positive at all lumbar intervertebral disc levels and was higher in the field group than in the administrative group at each level. In logistic regression analysis, type of job was statistically significant only with regard to the L4–5 intervertebral disc (OR 3.498, 95% CI 1.241 to 9.860). Conclusions Lumbar intervertebral disc degeneration is associated with age, and field work such as firefighting, emergency and rescue may accelerate degeneration in the L4–5 intervertebral disc. The effects of field work on lumbar intervertebral disc degeneration were not clear in discs other than at the level L4–5. PMID:27354080

  4. 22. Float located adjacent to entry stair in filtration bed. ...

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

    22. Float located adjacent to entry stair in filtration bed. The float actuates a valve that maintains water level over the bed. - Lake Whitney Water Filtration Plant, Filtration Plant, South side of Armory Street between Edgehill Road & Whitney Avenue, Hamden, New Haven County, CT

  5. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  6. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

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

  7. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  8. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  9. 43 CFR 420.3 - Adjacent lands.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  10. General Pathophysiology in Retinal Degeneration

    PubMed Central

    Wert, Katherine J.; Lin, Jonathan H.; Tsang, Stephen H.

    2015-01-01

    Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/ or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6β) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade. PMID:24732759

  11. Awareness, Knowledge, and Concern about Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Cimarolli, Verena R.; Laban-Baker, Allie; Hamilton, Wanda S.; Stuen, Cynthia

    2012-01-01

    Age-related macular degeneration (AMD)--a common eye disease causing vision loss--can be detected early through regular eye-health examinations, and measures can be taken to prevent visual decline. Getting eye examinations requires certain levels of awareness, knowledge, and concern related to AMD. However, little is known about AMD-related…

  12. Quantum degenerate exciton-polaritons in thermal equilibrium.

    PubMed

    Deng, Hui; Press, David; Götzinger, Stephan; Solomon, Glenn S; Hey, Rudolf; Ploog, Klaus H; Yamamoto, Yoshihisa

    2006-10-06

    We study the momentum distribution and relaxation dynamics of semiconductor microcavity polaritons by angle-resolved and time-resolved spectroscopy. Above a critical pump level, the thermalization time of polaritons at positive detunings becomes shorter than their lifetime, and the polaritons form a quantum degenerate Bose-Einstein distribution in thermal equilibrium with the lattice.

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

    PubMed Central

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

    2013-01-01

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

  14. [Age-related macular degeneration].

    PubMed

    Budzinskaia, M V

    2014-01-01

    The review provides an update on the pathogenesis and new treatment modalities for neovascular age-related macular degeneration (AMD). The impact of polymorphism in particular genes, including complement factor H (CFH), age-related maculopathy susceptibility 2 (ARMS2/LOC387715), and serine peptidase (HTRA1), on AMD development is discussed. Clinical presentations of different forms of exudative AMD, that is classic, occult, or more often mixed choroidal neovascularization, retinal angiomatous proliferation, and choroidal polypoidal vasculopathy, are described. Particular attention is paid to the results of recent clinical trials and safety issues around the therapy.

  15. Degeneration of a Nonrecombining Chromosome

    NASA Astrophysics Data System (ADS)

    Rice, William R.

    1994-01-01

    Comparative studies suggest that sex chromosomes begin as ordinary autosomes that happen to carry a major sex determining locus. Over evolutionary time the Y chromosome is selected to stop recombining with the X chromosome, perhaps in response to accumulation of alleles beneficial to the heterogametic but harmful to the homogametic sex. Population genetic theory predicts that a nonrecombining Y chromosome should degenerate. Here this prediction is tested by application of specific selection pressures to Drosophila melanogaster populations. Results demonstrate the decay of a nonrecombining, nascent Y chromosome and the capacity for recombination to ameliorate such decay.

  16. Age-related macular degeneration

    PubMed Central

    Querques, Giuseppe; Avellis, Fernando Onofrio; Querques, Lea; Bandello, Francesco; Souied, Eric H

    2011-01-01

    Clinical question: Is there any new knowledge about the pathogenesis and treatment of age-related macular degeneration (AMD)? Results: We now understand better the biochemical and pathological pathways involved in the genesis of AMD. Treatment of exudative AMD is based on intravitreal injection of new antivascular endothelial growth factor drugs for which there does not yet exist a unique recognized strategy of administration. No therapies are actually available for atrophic AMD, despite some experimental new pharmacological approaches. Implementation: strategy of administration, safety of intravitreal injection PMID:21654887

  17. Mathematical glimpse on the Y chromosome degeneration

    NASA Astrophysics Data System (ADS)

    Lobo, M. P.

    2006-04-01

    The Y chromosomes are genetically degenerate and do not recombine with their matching partners X. Non-recombination of XY pairs has been pointed out as the key factor for the degeneration of the Y chromosome. The aim here is to show that there is a mathematical asymmetry in sex chromosomes which leads to the degeneration of Y chromosomes even in the absence of XX and XY recombination. A model for sex-chromosome evolution in a stationary regime is proposed. The consequences of their asymmetry are analyzed and lead us to a couple of conclusions. First, Y chromosome degeneration shows up sqrt{2} more often than X chromosome degeneration. Second, if nature prohibits female mortalities from beeing exactly 50%, then Y chromosome degeneration is inevitable.

  18. Parainflammation, chronic inflammation, and age-related macular degeneration.

    PubMed

    Chen, Mei; Xu, Heping

    2015-11-01

    Inflammation is an adaptive response of the immune system to noxious insults to maintain homeostasis and restore functionality. The retina is considered an immune-privileged tissue as a result of its unique anatomic and physiologic properties. During aging, the retina suffers from a low-grade chronic oxidative insult, which sustains for decades and increases in level with advancing age. As a result, the retinal innate-immune system, particularly microglia and the complement system, undergoes low levels of activation (parainflammation). In many cases, this parainflammatory response can maintain homeostasis in the healthy aging eye. However, in patients with age-related macular degeneration, this parainflammatory response becomes dysregulated and contributes to macular damage. Factors contributing to the dysregulation of age-related retinal parainflammation include genetic predisposition, environmental risk factors, and old age. Dysregulated parainflammation (chronic inflammation) in age-related macular degeneration damages the blood retina barrier, resulting in the breach of retinal-immune privilege, leading to the development of retinal lesions. This review discusses the basic principles of retinal innate-immune responses to endogenous chronic insults in normal aging and in age-related macular degeneration and explores the difference between beneficial parainflammation and the detrimental chronic inflammation in the context of age-related macular degeneration.

  19. Effect of calcitonin pretreatment on naturally occurring intervertebral disc degeneration in guinea pig

    PubMed Central

    Jiang, Xiaohua; Tian, Faming; Wang, Wenya; Yan, Jinyin; Liu, Huanjiang; Liu, Binbin; Song, Huiping; Zhang, Yingze; Shen, Yong; Zhang, Liu

    2015-01-01

    elastic modulus increased from 3 to 6 months old and thereafter maintained in a stable level, which were enhanced by CT treatment. Conclusion: Pretreatment with CT could prevent naturally occurring intervertebral disc degeneration in guinea pigs, which might be related to the modulation of extracellular matrix metabolism and the integrity and biomechanical properties in adjacent vertebral body. PMID:26379827

  20. [Pathogenesis of age-related macular degeneration].

    PubMed

    Kaarniranta, Kai; Seitsonen, Sanna; Paimela, Tuomas; Meri, Seppo; Immonen, Ilkka

    2009-01-01

    Age-related macular degeneration is a multiform disease of the macula, the region responsible for detailed central vision. In recent years, plenty of new knowledge of the pathogenesis of this disease has been obtained, and the treatment of exudative macular degeneration has greatly progressed. The number of patients with age-related macular degeneration will multiply in the following decades, because knowledge of mechanisms of development of macular degeneration that could be subject to therapeutic measures is insufficient. Central underlying factors are genetic inheritance, exposure of the retina to chronic oxidative stress and accumulation of inflammation-inducing harmful proteins into or outside of retinal cells.

  1. Decreased Expression of DREAM Promotes the Degeneration of Retinal Neurons

    PubMed Central

    Chintala, Shravan; Cheng, Mei; Zhang, Xiao

    2015-01-01

    The intrinsic mechanisms that promote the degeneration of retinal ganglion cells (RGCs) following the activation of N-Methyl-D-aspartic acid-type glutamate receptors (NMDARs) are unclear. In this study, we have investigated the role of downstream regulatory element antagonist modulator (DREAM) in NMDA-mediated degeneration of the retina. NMDA, phosphate-buffered saline (PBS), and MK801 were injected into the vitreous humor of C57BL/6 mice. At 12, 24, and 48 hours after injection, expression of DREAM in the retina was determined by immunohistochemistry, western blot analysis, and electrophoretic mobility-shift assay (EMSA). Apoptotic death of cells in the retina was determined by terminal deoxynucleotidyl transferace dUTP nick end labeling (TUNEL) assays. Degeneration of RGCs in cross sections and in whole mount retinas was determined by using antibodies against Tuj1 and Brn3a respectively. Degeneration of amacrine cells and bipolar cells was determined by using antibodies against calretinin and protein kinase C (PKC)-alpha respectively. DREAM was expressed constitutively in RGCs, amacrine cells, bipolar cells, as well as in the inner plexiform layer (IPL). NMDA promoted a progressive decrease in DREAM levels in all three cell types over time, and at 48 h after NMDA-treatment very low DREAM levels were evident in the IPL only. DREAM expression in retinal nuclear proteins was decreased progressively after NMDA-treatment, and correlated with its decreased binding to the c-fos-DRE oligonucleotides. A decrease in DREAM expression correlated significantly with apoptotic death of RGCs, amacrine cells and bipolar cells. Treatment of eyes with NMDA antagonist MK801, restored DREAM expression to almost normal levels in the retina, and significantly decreased NMDA-mediated apoptotic death of RGCs, amacrine cells, and bipolar cells. Results presented in this study show for the first time that down-regulation of DREAM promotes the degeneration of RGCs, amacrine cells, and

  2. Decreased Expression of DREAM Promotes the Degeneration of Retinal Neurons.

    PubMed

    Chintala, Shravan; Cheng, Mei; Zhang, Xiao

    2015-01-01

    The intrinsic mechanisms that promote the degeneration of retinal ganglion cells (RGCs) following the activation of N-Methyl-D-aspartic acid-type glutamate receptors (NMDARs) are unclear. In this study, we have investigated the role of downstream regulatory element antagonist modulator (DREAM) in NMDA-mediated degeneration of the retina. NMDA, phosphate-buffered saline (PBS), and MK801 were injected into the vitreous humor of C57BL/6 mice. At 12, 24, and 48 hours after injection, expression of DREAM in the retina was determined by immunohistochemistry, western blot analysis, and electrophoretic mobility-shift assay (EMSA). Apoptotic death of cells in the retina was determined by terminal deoxynucleotidyl transferace dUTP nick end labeling (TUNEL) assays. Degeneration of RGCs in cross sections and in whole mount retinas was determined by using antibodies against Tuj1 and Brn3a respectively. Degeneration of amacrine cells and bipolar cells was determined by using antibodies against calretinin and protein kinase C (PKC)-alpha respectively. DREAM was expressed constitutively in RGCs, amacrine cells, bipolar cells, as well as in the inner plexiform layer (IPL). NMDA promoted a progressive decrease in DREAM levels in all three cell types over time, and at 48 h after NMDA-treatment very low DREAM levels were evident in the IPL only. DREAM expression in retinal nuclear proteins was decreased progressively after NMDA-treatment, and correlated with its decreased binding to the c-fos-DRE oligonucleotides. A decrease in DREAM expression correlated significantly with apoptotic death of RGCs, amacrine cells and bipolar cells. Treatment of eyes with NMDA antagonist MK801, restored DREAM expression to almost normal levels in the retina, and significantly decreased NMDA-mediated apoptotic death of RGCs, amacrine cells, and bipolar cells. Results presented in this study show for the first time that down-regulation of DREAM promotes the degeneration of RGCs, amacrine cells, and

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

    SciTech Connect

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

    1988-02-01

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

  4. Late onset cerebellar cortical degeneration in a koala.

    PubMed

    Kuwamura, M; Murai, F; Nishioka, S; Aoki, M; Ohashi, F; Yamate, J; Kotani, T; Summers, B A

    2009-08-01

    A 10-year-old male koala started to fall from the tree while sleeping. Subsequently, the koala often fell down while walking and showed a gait abnormality, abnormal nystagmus and hypersalivation. At 12 years of age, the koala became ataxic and seemed blind. At 13 years of age, the koala exhibited signs of dysstasia and was euthanased. Necropsy revealed marked symmetrical atrophy of the cerebellum. Histopathologically, a severe loss of Purkinje and granule cells was evident in the cerebellum, while the molecular layer was more cellular than normal with cells resembling small neurons, which were positively stained with parvalbumin immunohistochemistry. Reactive Bergmann glial cells (astrocytes) were present adjacent to the depleted Purkinje cell zone. The very late onset and slow progression of the cerebellar cortical degeneration in this case is particularly interesting and appears to be the first report in the koala.

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

    PubMed Central

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

    2014-01-01

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

  6. Photoreceptor Cells Influence Retinal Vascular Degeneration in Mouse Models of Retinal Degeneration and Diabetes

    PubMed Central

    Liu, Haitao; Tang, Jie; Du, Yunpeng; Saadane, Aicha; Tonade, Deoye; Samuels, Ivy; Veenstra, Alex; Palczewski, Krzysztof; Kern, Timothy S.

    2016-01-01

    Purpose Loss of photoreceptor cells is associated with retinal vascular degeneration in retinitis pigmentosa, whereas the presence of photoreceptor cells is implicated in vascular degeneration in diabetic retinopathy. To investigate how both the absence and presence of photoreceptors could damage the retinal vasculature, we compared two mouse models of photoreceptor degeneration (opsin−/− and RhoP23H/P23H ) and control C57Bl/5J mice, each with and without diabetes. Methods Retinal thickness, superoxide, expression of inflammatory proteins, ERG and optokinetic responses, leukocyte cytotoxicity, and capillary degeneration were evaluated at 1 to 10 months of age using published methods. Results Retinal photoreceptor cells degenerated completely in the opsin mutants by 2 to 4 months of age, and visual function subsided correspondingly. Retinal capillary degeneration was substantial while photoreceptors were still present, but slowed after the photoreceptors degenerated. Diabetes did not further exacerbate capillary degeneration in these models of photoreceptor degeneration, but did cause capillary degeneration in wild-type animals. Photoreceptor cells, however, did not degenerate in wild-type diabetic mice, presumably because the stress responses in these cells were less than in the opsin mutants. Retinal superoxide and leukocyte damage to retinal endothelium contributed to the degeneration of retinal capillaries in diabetes, and leukocyte-mediated damage was increased in both opsin mutants during photoreceptor cell degeneration. Conclusions Photoreceptor cells affect the integrity of the retinal microvasculature. Deterioration of retinal capillaries in opsin mutants was appreciable while photoreceptor cells were present and stressed, but was less after photoreceptors degenerated. This finding proves relevant to diabetes, where persistent stress in photoreceptors likewise contributes to capillary degeneration. PMID:27548901

  7. Regularized degenerate multi-solitons

    NASA Astrophysics Data System (ADS)

    Correa, Francisco; Fring, Andreas

    2016-09-01

    We report complex {P}{T} -symmetric multi-soliton solutions to the Korteweg de-Vries equation that asymptotically contain one-soliton solutions, with each of them possessing the same amount of finite real energy. We demonstrate how these solutions originate from degenerate energy solutions of the Schrödinger equation. Technically this is achieved by the application of Darboux-Crum transformations involving Jordan states with suitable regularizing shifts. Alternatively they may be constructed from a limiting process within the context Hirota's direct method or on a nonlinear superposition obtained from multiple Bäcklund transformations. The proposed procedure is completely generic and also applicable to other types of nonlinear integrable systems.

  8. Degenerate doping of metallic anodes

    DOEpatents

    Friesen, Cody A; Zeller, Robert A; Johnson, Paul B; Switzer, Elise E

    2015-05-12

    Embodiments of the invention relate to an electrochemical cell comprising: (i) a fuel electrode comprising a metal fuel, (ii) a positive electrode, (iii) an ionically conductive medium, and (iv) a dopant; the electrodes being operable in a discharge mode wherein the metal fuel is oxidized at the fuel electrode and the dopant increases the conductivity of the metal fuel oxidation product. In an embodiment, the oxidation product comprises an oxide of the metal fuel which is doped degenerately. In an embodiment, the positive electrode is an air electrode that absorbs gaseous oxygen, wherein during discharge mode, oxygen is reduced at the air electrode. Embodiments of the invention also relate to methods of producing an electrode comprising a metal and a doped metal oxidation product.

  9. Neural reprogramming in retinal degenerations

    PubMed Central

    Marc, Robert E.; Jones, Bryan W.; Anderson, James R.; Kinard, Krista; Marshak, David W.; Wilson, John H.; Wensel, Theodore; Lucas, Robert J.

    2008-01-01

    Purpose Early visual defects in degenerative diseases such as retinitis pigmentosa (RP) may arise from phased remodeling of the neural retina. We sought to explore the functional expression of ionotropic (iGluR) and group III, type 6 metabotropic (mGluR6) glutamate receptors in late-stage photoreceptor degenerations. Methods Excitation mapping with organic cations and computational molecular phenotyping were used to determine whether retinal neurons displayed functional glutamate receptor signaling in rodent models of retinal degenerations and a sample of human RP. Results After photoreceptor loss in rodent models of RP, bipolar cells lose mGluR6 and iGluR glutamate-activated currents, while amacrine and ganglion cells retain iGluR-mediated responsivity. Paradoxically, amacrine and ganglion cells show spontaneous iGluR signals in vivo even though bipolar cells lack glutamate-coupled depolarization mechanisms. Cone survival can rescue iGluR expression by OFF bipolar cells. In a case of human RP with cone sparing, iGluR signaling appeared intact, but the numbers of bipolar cells expressing functional iGluRs was double that of normal retina. Conclusions RP triggers permanent loss of bipolar cell glutamate receptor expression, though spontaneous iGluR-mediated signaling by amacrine and ganglion cells implies that such truncated bipolar cells still release glutamate in response to some non-glutamatergic depolarization. Focal cone-sparing can preserve iGluR display by nearby bipolar cells, which may facilitate late-RP photoreceptor transplant attempts. An instance of human RP provides evidence that rod bipolar cell dendrite switching likely triggers new gene expression patterns and may impair cone pathway function. PMID:17591910

  10. Exact propagators for some degenerate hyperbolic operators

    NASA Astrophysics Data System (ADS)

    Beals, Richard; Kannai, Yakar

    2006-10-01

    Exact propagators are obtained for the degenerate second order hyperbolic operators ∂2 t - t 2 l Δ x , l=1,2,..., by analytic continuation from the degenerate elliptic operators ∂2 t + t 2 l Δ x . The partial Fourier transforms are also obtained in closed form, leading to integral transform formulas for certain combinations of Bessel functions and modified Bessel functions.

  11. Seismic analysis of adjacent buildings subjected to double pounding considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Farghaly, Ahmed Abdelraheem

    2017-02-01

    A 2D model of two adjacent buildings with different heights (6 and 12 floors) and foundation levels without separation distance under seismic load and considering SSI is investigated. A special arrangement of contact elements (gap elements) each 1 m of the low height building in the contact zone is taken into consideration to fulfill all possible deformation contact modes which take place under seismic load (earthquake). Soil is modeled by 2D shell elements in contact with foundations of the two adjacent buildings. This paper focuses on the study of double pounding that takes place between the two adjacent buildings in some upper points at superstructure in the contact zone and also at foundation level. The forces of double pounding between the two adjacent buildings, which increase by softening of the soil, give a valuable assessment of straining actions of the two adjacent buildings and change the behavior of soil under the foundations and around basement floor.

  12. Seismic analysis of adjacent buildings subjected to double pounding considering soil-structure interaction

    NASA Astrophysics Data System (ADS)

    Farghaly, Ahmed Abdelraheem

    2017-03-01

    A 2D model of two adjacent buildings with different heights (6 and 12 floors) and foundation levels without separation distance under seismic load and considering SSI is investigated. A special arrangement of contact elements (gap elements) each 1 m of the low height building in the contact zone is taken into consideration to fulfill all possible deformation contact modes which take place under seismic load (earthquake). Soil is modeled by 2D shell elements in contact with foundations of the two adjacent buildings. This paper focuses on the study of double pounding that takes place between the two adjacent buildings in some upper points at superstructure in the contact zone and also at foundation level. The forces of double pounding between the two adjacent buildings, which increase by softening of the soil, give a valuable assessment of straining actions of the two adjacent buildings and change the behavior of soil under the foundations and around basement floor.

  13. Tamoxifen Provides Structural and Functional Rescue in Murine Models of Photoreceptor Degeneration.

    PubMed

    Wang, Xu; Zhao, Lian; Zhang, Yikui; Ma, Wenxin; Gonzalez, Shaimar R; Fan, Jianguo; Kretschmer, Friedrich; Badea, Tudor C; Qian, Hao-Hua; Wong, Wai T

    2017-03-22

    Photoreceptor degeneration is a cause of irreversible vision loss in incurable blinding retinal diseases including retinitis pigmentosa (RP) and atrophic age-related macular degeneration. We found in two separate mouse models of photoreceptor degeneration that tamoxifen, a selective estrogen receptor modulator and a drug previously linked with retinal toxicity, paradoxically provided potent neuroprotective effects. In a light-induced degeneration model, tamoxifen prevented onset of photoreceptor apoptosis and atrophy and maintained near-normal levels of electroretinographic responses. Rescue effects were correlated with decreased microglial activation and inflammatory cytokine production in the retina in vivo and a reduction of microglia-mediated toxicity to photoreceptors in vitro, indicating a microglia-mediated mechanism of rescue. Tamoxifen also rescued degeneration in a genetic (Pde6b(rd10)) model of RP, significantly improving retinal structure, electrophysiological responses, and visual behavior. These prominent neuroprotective effects warrant the consideration of tamoxifen as a drug suitable for being repurposed to treat photoreceptor degenerative disease.SIGNIFICANCE STATEMENT Photoreceptor degeneration is a cause of irreversible blindness in a number of retinal diseases such as retinitis pigmentosa (RP) and atrophic age-related macular degeneration. Tamoxifen, a selective estrogen receptor modulator approved for the treatment of breast cancer and previously linked to a low incidence of retinal toxicity, was unexpectedly found to exert marked protective effects against photoreceptor degeneration. Structural and functional protective effects were found for an acute model of light-induced photoreceptor injury and for a genetic model for RP. The mechanism of protection involved the modulation of microglial activation and the production of inflammatory cytokines, highlighting the role of inflammatory mechanisms in photoreceptor degeneration. Tamoxifen may be

  14. Structure formation through self-gravitational instability in degenerate and non-degenerate anisotropic magnetized plasma

    NASA Astrophysics Data System (ADS)

    Sharma, Prerana

    2017-04-01

    The self-gravitational instability is examined for non-degenerate and degenerate magnetized plasma. In the case of non-degenerate collisionless magnetized plasma the pressure is considered as anisotropic while in the case of degenerate situations it is taken as isotropic. The effect of finite Larmor radius correction of non-degenerate ions and viscous dissipation is taken into account in both the cases. Firstly in non-degenerate anisotropic plasma the conventional magnetohydrodynamic model is used to construct basic set of equations within the framework of modified Chew-Goldberger and Low theory. Secondly, in the case of degenerate isotropic plasma, which is considered to be composed of degenerate electrons and non-degenerate ions, the model equations are constructed using quantum magneto hydrodynamic model. The dynamics of degenerate particles are governed by Bohm and exchange potentials. The general dispersion relations are derived for both degenerate and non-degenerate situations separately using linearized perturbation equations. The results are discussed analytically and numerically for various modes of propagation. In case of non degenerate strongly magnetized plasma the effects of stress tensor anisotropy dominate over the influence of FLR effects while the FLR effects prevail in the weak magnetic field region. In case of isotropic degenerate plasma the implications of exchange parameter on the Jeans mass have been estimated and it is found that the increase in exchange parameter increases the limit of Jeans mass. The Jeans length and Jeans mass have been estimated for the white dwarf stars as LJ ≈ 2.1 × 10^{11} m and MJ ≈ 5 × 10^{39} kg respectively assist the existence of super Chandrasekhar white dwarfs.

  15. A Novel Technique for Rejuvenation of Degenerated Caterpillar Medicinal Mushroom, Cordyceps militaris (Ascomycetes), a Valued Traditional Chinese Medicine.

    PubMed

    Chen, Anhui; Wang, Yulong; Shao, Ying; Huang, Bo

    2017-01-01

    Cordyceps militaris has been used in traditional Chinese medicine for many years, but its frequent degeneration during continuous maintenance in culture can lead to substantial commercial losses. In this study, a degenerated strain of C. militaris was obtained by subculturing a wild-type strain through 10 successive subcultures. The relative abundance of the 2 mating types seems to be out of balance in the degenerated strain. By cross-mating 4 single-ascospore isolates (2 for MAT 1-1 and 2 for MAT 1-2) from the degenerated strain, we were able to restore fruiting body production to wild-type levels. The rejuvenated strain not only produced well-developed fruiting bodies but also accumulated more cordycepin and adenosine than either the original wild-type strain or the degenerated strain. These new characteristics remained stable after 4 successive transfers, which indicates that the method used to rejuvenate the degenerated strain in this study is an effective approach.

  16. Suppression of Density Fluctuations in a Quantum Degenerate Fermi Gas

    SciTech Connect

    Sanner, Christian; Su, Edward J.; Keshet, Aviv; Gommers, Ralf; Shin, Yong-il; Huang Wujie; Ketterle, Wolfgang

    2010-07-23

    We study density profiles of an ideal Fermi gas and observe Pauli suppression of density fluctuations (atom shot noise) for cold clouds deep in the quantum degenerate regime. Strong suppression is observed for probe volumes containing more than 10 000 atoms. Measuring the level of suppression provides sensitive thermometry at low temperatures. After this method of sensitive noise measurements has been validated with an ideal Fermi gas, it can now be applied to characterize phase transitions in strongly correlated many-body systems.

  17. Age related macular degeneration and visual disability.

    PubMed

    Christoforidis, John B; Tecce, Nicola; Dell'Omo, Roberto; Mastropasqua, Rodolfo; Verolino, Marco; Costagliola, Ciro

    2011-02-01

    substantial benefit in people with age-related macular degeneration. Prescription filters are one of the most beneficial visual aids that people with macular degeneration. In principle, one aims both at reducing short-wavelength light to reduce glare and at identifying light with specific wavelengths (colours) preferred by the patient for viewing. In both instances, such interventions result in apparent improved contrast sensitivity and better visual acuity. Although specific tests are performed to determine the best colour, tint, lens material, and type of frame for the patient's need, no scientific protocol has been developed so far to assist in prescribing tinted or selective transmission lenses . Magnifying optical lenses are available in a wide range of dioptric powers and are made from materials that correct for weight (plastic), thickness (high index), spherical aberrations (aspherical), and variable light intensities (photochromatic). These lenses can be used as loose lenses, mounted on optical frames, or used with a wide variety of attachments. As the dioptric power of plus lenses increases, the viewing distance of the target decreases, hence their usefulness mainly for tasks requiring near resolution acuity, like reading. Magnification can also be achieved with the use of telescopic devices that are built of two or more plus and (or) minus (minifying) optical lenses. Normal resolution acuity levels can be achieved with these devices for all viewing distances. Therefore, all telescopic devices are useful only for stationary patient tasks that do not require mobility and orientation. Electronic magnification has the great advantage over plus lenses of producing an acuity reserve enabling reading skills for almost all levels of visual acuity. The additional benefit provided is preservation of binocularity, even at high levels of visual disparity between the two eyes. Vision rehabilitation can help patients to maximize their remaining vision and adapt to activities of

  18. Modified gravitational instability of degenerate and non-degenerate dusty plasma

    NASA Astrophysics Data System (ADS)

    Jain, Shweta; Sharma, Prerana

    2016-09-01

    The gravitational instability of strongly coupled dusty plasma (SCDP) is studied considering degenerate and non-degenerate dusty plasma situations. The SCDP system is assumed to be composed of the electrons, ions, neutrals, and strongly coupled dust grains. First, in the high density regime, due to small interparticle distance, the electrons are considered degenerate, whereas the neutrals, dust grains, and ions are treated non-degenerate. In this case, the dynamics of inertialess electrons are managed by Fermi pressure and Bohm potential, while the inertialess ions are by only thermal pressure. Second, in the non-degenerate regime, both the electrons and ions are governed by the thermal pressure. The generalized hydrodynamic model and the normal mode analysis technique are employed to examine the low frequency waves and gravitational instability in both degenerate and non-degenerate cases. The general dispersion relation is discussed for a characteristic timescale which provides two regimes of frequency, i.e., hydrodynamic regime and kinetic regime. Analytical solutions reveal that the collisions reduce the growth rate and have a strong impact on structure formation in both degenerate and non-degenerate circumstances. Numerical estimation on the basis of observed parameters for the degenerate and non-degenerate cases is presented to show the effects of dust-neutral collisions and dust effective velocity in the presence of polarization force. The values of Jeans length and Jeans mass have been estimated for degenerate white dwarfs as Jeans length L J = 1.3 × 10 5 cm and Jeans mass M J = 0.75 × 10 - 3 M⊙ and for non-degenerate laboratory plasma Jeans length L J = 6.86 × 10 16 cm and Jeans mass M J = 0.68 × 10 10 M⊙. The stability of the SCDP system is discussed using the Routh-Hurwitz criterion.

  19. Association between apparent diffusion coefficient and intervertebral disc degeneration in patients with ankylosing spondylitis

    PubMed Central

    Resorlu, Mustafa; Gokmen, Ferhat; Resorlu, Hatice; Adam, Gurhan; Akbal, Ayla; Cevizci, Sibel; Sariyildirim, Abdullah; Savas, Yilmaz; Guven, Mustafa; Aras, Adem Bozkurt

    2015-01-01

    Purpose: To assess the relation between ankylosing spondylitis (AS) and degenerative disc disease emerging in association with various intrinsic and extrinsic factors and to evaluate the correlation between degree of degeneration in intervertebral discs and apparent diffusion coefficient (ADC) values. Methods: Thirty-five patients with AS and a control group of 35 patients were included in the study. Three hundred fifty intervertebral discs were assessed in terms of degeneration by analyzing signal intensities and morphologies on T2 weighted series of a 1.5 Tesla magnetic resonance scanner. ADC values were determined in diffusion weighted images (DWI) using a “b value of 500 s/mm2”. Patients in the AS and control groups were compared in terms of intervertebral disc degeneration, and association between degree of degeneration and ADC values was analyzed. Results: The mean of total degeneration degrees for five lumbar intervertebral discs was significantly higher in the patients with AS compared to the control group (16.77±4.67 vs 13.00±4.08, respectively; P=0.001). When intervertebral discs were analyzed separately, disc degeneration was again significantly higher in patients with AS compared to the control group, with the exception of L5-S1. Age, cholesterol level, triglyceride level, duration of disease and BASFI index were significantly associated with degree of degeneration in patients with AS. A negative correlation was determined between disc degeneration and ADC value. Conclusion: AS is a risk factor for degenerative disc disease due to its systemic effects, the fact it leads to posture impairment and its inflammatory effects on the vertebrae. A decrease in ADC values is observed as degeneration worsens in degenerative disc disease. PMID:25785119

  20. Total absorption by degenerate critical coupling

    SciTech Connect

    Piper, Jessica R. Liu, Victor; Fan, Shanhui

    2014-06-23

    We consider a mirror-symmetric resonator with two ports. We show that, when excited from a single port, complete absorption can be achieved through critical coupling to degenerate resonances with opposite symmetry. Moreover, any time two resonances with opposite symmetry are degenerate in frequency and absorption is always significantly enhanced. In contrast, when two resonances with the same symmetry are nearly degenerate, there is no absorption enhancement. We numerically demonstrate these effects using a graphene monolayer on top of a photonic crystal slab, illuminated from a single side in the near-infrared.

  1. Molecular Therapy for Disk Degeneration and Pain

    PubMed Central

    Mwale, Fackson

    2013-01-01

    The nucleus pulposus of the intervertebral disk contains high amounts of the proteoglycan aggrecan, which confers the disk with a remarkable ability to resist compression. Other molecules such as collagens and noncollagenous proteins in the extracellular matrix are also essential for function. During disk degeneration, aggrecan and other molecules are lost due to proteolysis. This can result in loss of disk height, which can ultimately lead to pain. Biological therapy of intervertebral disk degeneration aims at preventing or restoring primarily aggrecan content and other molecules using therapeutic molecules. The purpose of the article is to review recent advances in biological repair of degenerate disks and pain. PMID:24436869

  2. Very Degenerate Higgsino Dark Matter

    NASA Astrophysics Data System (ADS)

    Chun, Eung Jin; Jung, Sunghoon; Park, Jong-Chul

    2017-01-01

    We present a study of the Very Degenerate Higgsino Dark Matter (DM), whose mass splitting between the lightest neutral and charged components is O(1) MeV, much smaller than radiative splitting of 355 MeV. The scenario is realized in the minimal supersymmetric standard model by small gaugino mixings. In contrast to the pure Higgsino DM with the radiative splitting only, various observable signatures with distinct features are induced. First of all, the very small mass splitting makes (a) sizable Sommerfeld enhancement and Ramsauer-Townsend (RT) suppression relevant to ˜1 TeV Higgsino DM, and (b) Sommerfeld-Ramsauer-Townsend effect saturate at lower velocities v/c ≲ 10-3. As a result, annihilation signals can be large enough to be observed from the galactic center and/or dwarf galaxies, while the relative signal sizes can vary depending on the locations of Sommerfeld peaks and RT dips. In addition, at collider experiments, stable chargino signatures can be searched for to probe the model in the future. DM direct detection signals, however, depend on the Wino mass; even no detectable signals can be induced if the Wino is heavier than about 10 TeV.

  3. Imaging of Lesser Metatarsophalangeal Joint Plantar Plate Degeneration, Tear, and Repair.

    PubMed

    Linklater, James M; Bird, Stephen J

    2016-04-01

    Plantar plate degeneration and tear is a common cause of forefoot pain, typically involving the second metatarsophalangeal joint at the proximal phalangeal insertion laterally, frequently confused with the second web space Morton neuroma. The condition has received increased attention with the development of surgical techniques that can result in successful repair of the plantar plate and substantial improvement in patient symptoms. High-resolution MRI or ultrasound can confirm a diagnosis of plantar plate degeneration and tear and exclude other pathologies, particularly Morton neuroma. The normal plantar plate is a mildly hyperechoic structure on ultrasound and is hypointense on all conventional MR sequences. Plantar plate degeneration manifests on ultrasound as hypoechoic echotextural change and on MRI as mild signal hyperintensity on short TE sequences, becoming less conspicuous on long TE sequences. Adjacent entheseal bony irregularity is commonly present. Plantar plate tears on ultrasound may be seen as an anechoic cleft defect or area of heterogeneous echotexture, sometimes more conspicuous with dorsiflexion stress. Plantar plate tears demonstrate greater signal hyperintensity on proton-density sequences, becoming more conspicuous on fat-suppressed proton density and T2-weighted sequences. Edema and fibrotic change in the pericapsular fat plane is commonly seen in the setting of an adjacent plantar plate tear and should not be misinterpreted as reflecting a Morton neuroma.

  4. dnc-1/dynactin 1 knockdown disrupts transport of autophagosomes and induces motor neuron degeneration.

    PubMed

    Ikenaka, Kensuke; Kawai, Kaori; Katsuno, Masahisa; Huang, Zhe; Jiang, Yue-Mei; Iguchi, Yohei; Kobayashi, Kyogo; Kimata, Tsubasa; Waza, Masahiro; Tanaka, Fumiaki; Mori, Ikue; Sobue, Gen

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive loss of motor neurons. We previously showed that the expression of dynactin 1, an axon motor protein regulating retrograde transport, is markedly reduced in spinal motor neurons of sporadic ALS patients, although the mechanisms by which decreased dynactin 1 levels cause neurodegeneration have yet to be elucidated. The accumulation of autophagosomes in degenerated motor neurons is another key pathological feature of sporadic ALS. Since autophagosomes are cargo of dynein/dynactin complexes and play a crucial role in the turnover of several organelles and proteins, we hypothesized that the quantitative loss of dynactin 1 disrupts the transport of autophagosomes and induces the degeneration of motor neuron. In the present study, we generated a Caenorhabditis elegans model in which the expression of DNC-1, the homolog of dynactin 1, is specifically knocked down in motor neurons. This model exhibited severe motor defects together with axonal and neuronal degeneration. We also observed impaired movement and increased number of autophagosomes in the degenerated neurons. Furthermore, the combination of rapamycin, an activator of autophagy, and trichostatin which facilitates axonal transport dramatically ameliorated the motor phenotype and axonal degeneration of this model. Thus, our results suggest that decreased expression of dynactin 1 induces motor neuron degeneration and that the transport of autophagosomes is a novel and substantial therapeutic target for motor neuron degeneration.

  5. Perceptual processing of adjacent and nonadjacent tactile nontargets.

    PubMed

    Evans, P M; Craig, J C; Rinker, M A

    1992-11-01

    Previous research has shown that subjects appear unable to restrict processing to a single finger and ignore a stimulus presented to an adjacent finger. Furthermore, the evidence suggests that, at least for moving stimuli, an adjacent nontarget is fully processed to the level of incipient response activation. The present study replicated and expanded upon these original findings. The results of Experiment 1 showed that an equally large response-competition effect occurred when the nontarget was presented to adjacent and nonadjacent fingers (on the same hand). The results of Experiment 2 showed that the effects observed in Experiment 1 (and in previous studies) were also obtained with stationary stimuli. Although small, there was some indication in the results of Experiment 2 that interference may dissipate more rapidly with distance with stationary stimuli. An additional finding was that interference effects were observed in both experiments with temporal separations between the target and nontarget of up to 100 msec. In Experiment 3, target and nontarget stimuli were presented to opposite hands. Although reduced, interference was still evident with target and nontarget stimuli presented to opposite hands. Varying the physical distance between hands did not produce any change in the amount of interference. The results suggest that the focus of attention on the skin extends nearly undiminished across the fingers of one hand and is not dependent upon the physical distance between sites of stimulation.

  6. Thermal Properties of Degenerate Relativistic Quantum Gases

    NASA Astrophysics Data System (ADS)

    Homorodean, Laurean

    We present the concentration-temperature phase diagram, characteristic functions, thermal equation of state and heat capacity at constant volume for degenerate ideal gases of relativistic fermions and bosons. The nonrelativistic and ultrarelativistic limits of these laws are also discussed.

  7. Macular Degeneration Prevention and Risk Factors

    MedlinePlus

    ... Degeneration Research National Glaucoma Research About Research Programs Leadership Partners Accountability Careers Grants Types of Grants Deadlines & ... Browse our A–Z index . About Research Programs Leadership Partners Accountability Careers Grants Types of Grants Deadlines & ...

  8. Hamiltonian structure for degenerate AKNS systems

    NASA Astrophysics Data System (ADS)

    Corona-Corona, Gulmaro

    1997-01-01

    There is a family of degenerate AKNS systems for which the full theory of generic AKNS systems does not directly extend. The linear space of potentials still has a natural Poisson structure, but the scattering method used by Beals and Sattinger to show complete integrability for the generic AKNS systems fails for the degenerate case. A Poisson structure is not induced on the scattering side as in the generic case. As a consequence, the problem of complete integrability for degenerate AKNS systems still is an open question. In addition, contrary to the generic case, the Lax pair gives flows for degenerate integrable systems that are nonlocal. In general, they do not exist, and they are no longer linear on the scattering side. Necessary conditions for their existence and for linear evolution in the scattering side are found.

  9. Hamiltonian Structure for Degenerate Akns Systems

    NASA Astrophysics Data System (ADS)

    Corona-Corona, Gulmaro

    1995-01-01

    There is a family of degenerate AKNS systems for which the full theory of generic AKNS systems does not directly extend. The linear space of potentials still has a natural Poisson structure. This is studied by the scattering method used by Richard Beals and D.H. Sattinger (Commun. Math. Phys. 138, 409-436, 1991) to show complete integrability for the generic AKNS systems. This method fails for the degenerate case since a Poisson structure is not induced on the scattering side as in the generic case. As a consequence, the problem of complete integrability for degenerate AKNS systems still is an open question. In addition, contrary to the generic case, the Lax pair gives flows for degenerate integrable systems that are nonlocal. In general they do not exist, and they are no longer linear on the scattering side. Necessary conditions for their existence and for linear evolution of the scattering side are found.

  10. Neural remodeling in retinal degeneration.

    PubMed

    Marc, Robert E; Jones, Bryan W; Watt, Carl B; Strettoi, Enrica

    2003-09-01

    Mammalian retinal degenerations initiated by gene defects in rods, cones or the retinal pigmented epithelium (RPE) often trigger loss of the sensory retina, effectively leaving the neural retina deafferented. The neural retina responds to this challenge by remodeling, first by subtle changes in neuronal structure and later by large-scale reorganization. Retinal degenerations in the mammalian retina generally progress through three phases. Phase 1 initiates with expression of a primary insult, followed by phase 2 photoreceptor death that ablates the sensory retina via initial photoreceptor stress, phenotype deconstruction, irreversible stress and cell death, including bystander effects or loss of trophic support. The loss of cones heralds phase 3: a protracted period of global remodeling of the remnant neural retina. Remodeling resembles the responses of many CNS assemblies to deafferentation or trauma, and includes neuronal cell death, neuronal and glial migration, elaboration of new neurites and synapses, rewiring of retinal circuits, glial hypertrophy and the evolution of a fibrotic glial seal that isolates the remnant neural retina from the surviving RPE and choroid. In early phase 2, stressed photoreceptors sprout anomalous neurites that often reach the inner plexiform and ganglion cell layers. As death of rods and cones progresses, bipolar and horizontal cells are deafferented and retract most of their dendrites. Horizontal cells develop anomalous axonal processes and dendritic stalks that enter the inner plexiform layer. Dendrite truncation in rod bipolar cells is accompanied by revision of their macromolecular phenotype, including the loss of functioning mGluR6 transduction. After ablation of the sensory retina, Müller cells increase intermediate filament synthesis, forming a dense fibrotic layer in the remnant subretinal space. This layer invests the remnant retina and seals it from access via the choroidal route. Evidence of bipolar cell death begins in

  11. Frontotemporal lobar degeneration: current perspectives

    PubMed Central

    Riedl, Lina; Mackenzie, Ian R; Förstl, Hans; Kurz, Alexander; Diehl-Schmid, Janine

    2014-01-01

    The term frontotemporal lobar degeneration (FTLD) refers to a group of progressive brain diseases, which preferentially involve the frontal and temporal lobes. Depending on the primary site of atrophy, the clinical manifestation is dominated by behavior alterations or impairment of language. The onset of symptoms usually occurs before the age of 60 years, and the mean survival from diagnosis varies between 3 and 10 years. The prevalence is estimated at 15 per 100,000 in the population aged between 45 and 65 years, which is similar to the prevalence of Alzheimer’s disease in this age group. There are two major clinical subtypes, behavioral-variant frontotemporal dementia and primary progressive aphasia. The neuropathology underlying the clinical syndromes is also heterogeneous. A common feature is the accumulation of certain neuronal proteins. Of these, the microtubule-associated protein tau (MAPT), the transactive response DNA-binding protein, and the fused in sarcoma protein are most important. Approximately 10% to 30% of FTLD shows an autosomal dominant pattern of inheritance, with mutations in the genes for MAPT, progranulin (GRN), and in the chromosome 9 open reading frame 72 (C9orf72) accounting for more than 80% of familial cases. Although significant advances have been made in recent years regarding diagnostic criteria, clinical assessment instruments, neuropsychological tests, cerebrospinal fluid biomarkers, and brain imaging techniques, the clinical diagnosis remains a challenge. To date, there is no specific pharmacological treatment for FTLD. Some evidence has been provided for serotonin reuptake inhibitors to reduce behavioral disturbances. No large-scale or high-quality studies have been conducted to determine the efficacy of non-pharmacological treatment approaches in FTLD. In view of the limited treatment options, caregiver education and support is currently the most important component of the clinical management. PMID:24600223

  12. Age-related macular degeneration.

    PubMed

    Cheung, Lily K; Eaton, Angie

    2013-08-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly, and the prevalence of the disease increases exponentially with every decade after age 50 years. It is a multifactorial disease involving a complex interplay of genetic, environmental, metabolic, and functional factors. Besides smoking, hypertension, obesity, and certain dietary habits, a growing body of evidence indicates that inflammation and the immune system may play a key role in the development of the disease. AMD may progress from the early form to the intermediate form and then to the advanced form, where two subtypes exist: the nonneovascular (dry) type and the neovascular (wet) type. The results from the Age-Related Eye Disease Study have shown that for the nonneovascular type of AMD, supplementation with high-dose antioxidants (vitamin C, vitamin E, and β-carotene) and zinc is recommended for those with the intermediate form of AMD in one or both eyes or with advanced AMD or vision loss due to AMD in one eye. As for the neovascular type of the advanced AMD, the current standard of therapy is intravitreal injections of vascular endothelial growth factor inhibitors. In addition, lifestyle and dietary modifications including improved physical activity, reduced daily sodium intake, and reduced intake of solid fats, added sugars, cholesterol, and refined grain foods are recommended. To date, no study has demonstrated that AMD can be cured or effectively prevented. Clearly, more research is needed to fully understand the pathophysiology as well as to develop prevention and treatment strategies for this devastating disease.

  13. Leveling

    USGS Publications Warehouse

    1966-01-01

    Geodetic leveling by the U.S. Geological Survey provides a framework of accurate elevations for topographic mapping. Elevations are referred to the Sea Level Datum of 1929. Lines of leveling may be run either with automatic or with precise spirit levels, by either the center-wire or the three-wire method. For future use, the surveys are monumented with bench marks, using standard metal tablets or other marking devices. The elevations are adjusted by least squares or other suitable method and are published in lists of control.

  14. Natural history of seminiferous tubule degeneration in Klinefelter syndrome.

    PubMed

    Aksglaede, Lise; Wikström, Anne M; Rajpert-De Meyts, Ewa; Dunkel, Leo; Skakkebaek, Niels E; Juul, Anders

    2006-01-01

    Klinefelter syndrome (47,XXY) is characterized by small, firm testis, gynaecomastia, azoospermia and hypergonadotropic hypogonadism. Degeneration of the seminiferous tubules in 47,XXY males is a well-described phenomenon. It begins in the fetus, progresses through infancy and accelerates dramatically at the time of puberty with complete hyalinization of the seminiferous tubules, although a few tubules with spermatogenesis may be present in adult life. Activation of the pituitary-gonadal axis at 3 months of age is seen in Klinefelter boys similar to healthy boys. However, the level of testosterone in Klinefelter boys is significantly lower than in controls. After this 'minipuberty', the hormone levels decline to normal prepubertal levels until puberty. In puberty, an initial rise in testosterone, inhibin B, LH and FSH occurs in Klinefelter boys. However, the rise in testosterone levels off and ends at a low-normal level in young adults. Likewise, serum concentration of inhibin B exhibits a dramatic decline to a low, often undetectable level, concomitantly with a rise in FSH, reflecting the degeneration of the seminiferous tubules. Many hypotheses about the underlying mechanism of the depletion of the germ cells in Klinefelter males have been reported and include insufficient supranumerary X-chromosome inactivation, Leydig cell insufficiency and disturbed regulation of apoptosis of Sertoli and Leydig cells. However, at present, the exact mechanism remains unclear. In this article, we summarize current knowledge on the development of the classical endocrinological and histological features of 47,XXY males from fetus to adulthood and review the literature concerning the degeneration of the seminiferous tubules in this syndrome.

  15. Quantal Density Functional Theory(Q-DFT) of Degenerate Ground and Excited States

    NASA Astrophysics Data System (ADS)

    Sahni, Viraht; Pan, Xiaoyin

    2002-03-01

    We present here Q-DFT (V.Sahni et al, PRL 87), 113002 (2001), and references therein. of degenerate states with degeneracy g. We describe : (a) The transformation from a degenerate ground or excited pure state of the interacting system to an S (single Slater determinant) system of noninteracting Fermions with equivalent density, total energy, and ionization potential; (b) The construction of g S systems to reproduce a subspace ensemble density and energy. The density and energy are defined via the ensemble density matrix formed from the degenerate ground or excited pure states of the interacting system; (c) The construction of an S system with a g-fold degenerate highest occupied level, (which leads to g Slater determinants (C.A. Ullrich and W. Kohn, PRL 87), 093001(2001).), to reproduce the ground or excited state ensemble density and energy.

  16. Hydropic degeneration of the anterior pituitary gland (adenohypophysis) in uremic rats.

    PubMed

    Levine, Seymour; Saltzman, Arthur

    2004-03-01

    We observed hydropic degeneration of the anterior pituitary in rats made uremic by nephrotoxic chemicals, especially when the uremic rats were given a pure carbohydrate diet beforehand. The hydropic degeneration caused loss of nuclear and cytoplasmic content of many or most anterior pituitary cells. It was readily visible in paraffin sections by light microscopy. It was exaggerated when water was injected after the nephrotoxin and it was greatly reduced if saline was injected after the nephrotoxin. Low serum sodium levels in affected rats and the response to saline injection suggested that the mechanism for development of hydropic degeneration of the anterior pituitary gland involved hyponatremia. Depletion of total body sodium probably accounts for the enhancement of hydropic degeneration by the pure carbohydrate diet. Morphologic lesions of the anterior pituitary related to hyponatremia and uremia have not been described previously.

  17. The Retromer Complex Is Required for Rhodopsin Recycling and Its Loss Leads to Photoreceptor Degeneration

    PubMed Central

    Wang, Shiuan; Tan, Kai Li; Agosto, Melina A.; Xiong, Bo; Yamamoto, Shinya; Sandoval, Hector; Jaiswal, Manish; Bayat, Vafa; Zhang, Ke; Charng, Wu-Lin; David, Gabriela; Duraine, Lita; Venkatachalam, Kartik; Wensel, Theodore G.; Bellen, Hugo J.

    2014-01-01

    Rhodopsin mistrafficking can cause photoreceptor (PR) degeneration. Upon light exposure, activated rhodopsin 1 (Rh1) in Drosophila PRs is internalized via endocytosis and degraded in lysosomes. Whether internalized Rh1 can be recycled is unknown. Here, we show that the retromer complex is expressed in PRs where it is required for recycling endocytosed Rh1 upon light stimulation. In the absence of subunits of the retromer, Rh1 is processed in the endolysosomal pathway, leading to a dramatic increase in late endosomes, lysosomes, and light-dependent PR degeneration. Reducing Rh1 endocytosis or Rh1 levels in retromer mutants alleviates PR degeneration. In addition, increasing retromer abundance suppresses degenerative phenotypes of mutations that affect the endolysosomal system. Finally, expressing human Vps26 suppresses PR degeneration in Vps26 mutant PRs. We propose that the retromer plays a conserved role in recycling rhodopsins to maintain PR function and integrity. PMID:24781186

  18. Arginase 2 promotes neurovascular degeneration during ischemia/reperfusion injury

    PubMed Central

    Shosha, Esraa; Xu, Zhimin; Yokota, Harumasa; Saul, Alan; Rojas, Modesto; Caldwell, R William; Caldwell, Ruth B; Narayanan, S Priya

    2016-01-01

    Retinal ischemia is a major cause of visual impairment and blindness and is involved in various disorders including diabetic retinopathy, glaucoma, optic neuropathies and retinopathy of prematurity. Neurovascular degeneration is a common feature of these pathologies. Our lab has previously reported that the ureahydrolase arginase 2 (A2) is involved in ischemic retinopathies. Here, we are introducing A2 as a therapeutic target to prevent neurovascular injury after retinal ischemia/reperfusion (I/R) insult. Studies were performed with mice lacking both copies of A2 (A2−/−) and wild-type (WT) controls (C57BL6J). I/R insult was conducted on the right eye and the left eye was used as control. Retinas were collected for analysis at different times (3 h–4 week after injury). Neuronal and microvascular degeneration were evaluated using NeuN staining and vascular digests, respectively. Glial activation was evaluated by glial fibrillary acidic protein expression. Necrotic cell death was studied by propidium iodide labeling and western blot for RIP-3. Arginase expression was determined by western blot and quantitative RT-PCR. Retinal function was determined by electroretinography (ERG). A2 mRNA and protein levels were increased in WT I/R. A2 deletion significantly reduced ganglion cell loss and microvascular degeneration and preserved retinal morphology after I/R. Glial activation, reactive oxygen species formation and cell death by necroptosis were significantly reduced by A2 deletion. ERG showed improved positive scotopic threshold response with A2 deletion. This study shows for the first time that neurovascular injury after retinal I/R is mediated through increased expression of A2. Deletion of A2 was found to be beneficial in reducing neurovascular degeneration after I/R. PMID:27882947

  19. Optic pathway degeneration in Japanese black cattle.

    PubMed

    Chiba, Shiori; Funato, Shingo; Horiuchi, Noriyuki; Matsumoto, Kotaro; Inokuma, Hisashi; Furuoka, Hidefumi; Kobayashi, Yoshiyasu

    2015-02-01

    Degeneration of the optic pathway has been reported in various animal species including cattle. We experienced a case of bilateral optic tract degeneration characterized by severe gliosis in a Japanese black cattle without any obvious visual defects. To evaluate the significance, pathological nature and pathogenesis of the lesions, we examined the optic pathway in 60 cattle (41 Japanese black, 13 Holstein and 6 crossbreed) with or without ocular abnormalities. None of these animals had optic canal stenosis. Degenerative changes with severe gliosis in the optic pathway, which includes the optic nerve, optic chiasm and optic tract, were only observed in 8 Japanese black cattle with or without ocular abnormalities. Furthermore, strong immunoreactivity of glial fibrillary acidic protein was observed in the retinal stratum opticum and ganglion cell layer in all 5 cattle in which the optic pathway lesions could be examined. As etiological research, we also examined whether the concentrations of vitamin A and vitamin B12 or bovine viral diarrhea virus (BVDV) infection was associated with optic pathway degeneration. However, our results suggested that the observed optic pathway degeneration was probably not caused by these factors. These facts indicate the presence of optic pathway degeneration characterized by severe gliosis that has never been reported in cattle without bilateral compressive lesions in the optic pathway or bilateral severe retinal atrophy.

  20. Optic pathway degeneration in Japanese black cattle

    PubMed Central

    CHIBA, Shiori; FUNATO, Shingo; HORIUCHI, Noriyuki; MATSUMOTO, Kotaro; INOKUMA, Hisashi; FURUOKA, Hidefumi; KOBAYASHI, Yoshiyasu

    2014-01-01

    Degeneration of the optic pathway has been reported in various animal species including cattle. We experienced a case of bilateral optic tract degeneration characterized by severe gliosis in a Japanese black cattle without any obvious visual defects. To evaluate the significance, pathological nature and pathogenesis of the lesions, we examined the optic pathway in 60 cattle (41 Japanese black, 13 Holstein and 6 crossbreed) with or without ocular abnormalities. None of these animals had optic canal stenosis. Degenerative changes with severe gliosis in the optic pathway, which includes the optic nerve, optic chiasm and optic tract, were only observed in 8 Japanese black cattle with or without ocular abnormalities. Furthermore, strong immunoreactivity of glial fibrillary acidic protein was observed in the retinal stratum opticum and ganglion cell layer in all 5 cattle in which the optic pathway lesions could be examined. As etiological research, we also examined whether the concentrations of vitamin A and vitamin B12 or bovine viral diarrhea virus (BVDV) infection was associated with optic pathway degeneration. However, our results suggested that the observed optic pathway degeneration was probably not caused by these factors. These facts indicate the presence of optic pathway degeneration characterized by severe gliosis that has never been reported in cattle without bilateral compressive lesions in the optic pathway or bilateral severe retinal atrophy. PMID:25421501

  1. The cell stress machinery and retinal degeneration.

    PubMed

    Athanasiou, Dimitra; Aguilà, Monica; Bevilacqua, Dalila; Novoselov, Sergey S; Parfitt, David A; Cheetham, Michael E

    2013-06-27

    Retinal degenerations are a group of clinically and genetically heterogeneous disorders characterised by progressive loss of vision due to neurodegeneration. The retina is a highly specialised tissue with a unique architecture and maintaining homeostasis in all the different retinal cell types is crucial for healthy vision. The retina can be exposed to a variety of environmental insults and stress, including light-induced damage, oxidative stress and inherited mutations that can lead to protein misfolding. Within retinal cells there are different mechanisms to cope with disturbances in proteostasis, such as the heat shock response, the unfolded protein response and autophagy. In this review, we discuss the multiple responses of the retina to different types of stress involved in retinal degenerations, such as retinitis pigmentosa, age-related macular degeneration and glaucoma. Understanding the mechanisms that maintain and re-establish proteostasis in the retina is important for developing new therapeutic approaches to fight blindness.

  2. 3D finite element analysis of nutrient distributions and cell viability in the intervertebral disc: effects of deformation and degeneration.

    PubMed

    Jackson, Alicia R; Huang, Chun-Yuh C; Brown, Mark D; Gu, Wei Yong

    2011-09-01

    The intervertebral disc (IVD) receives important nutrients, such as glucose, from surrounding blood vessels. Poor nutritional supply is believed to play a key role in disc degeneration. Several investigators have presented finite element models of the IVD to investigate disc nutrition; however, none has predicted nutrient levels and cell viability in the disc with a realistic 3D geometry and tissue properties coupled to mechanical deformation. Understanding how degeneration and loading affect nutrition and cell viability is necessary for elucidating the mechanisms of disc degeneration and low back pain. The objective of this study was to analyze the effects of disc degeneration and static deformation on glucose distributions and cell viability in the IVD using finite element analysis. A realistic 3D finite element model of the IVD was developed based on mechano-electrochemical mixture theory. In the model, the cellular metabolic activities and viability were related to nutrient concentrations, and transport properties of nutrients were dependent on tissue deformation. The effects of disc degeneration and mechanical compression on glucose concentrations and cell density distributions in the IVD were investigated. To examine effects of disc degeneration, tissue properties were altered to reflect those of degenerated tissue, including reduced water content, fixed charge density, height, and endplate permeability. Two mechanical loading conditions were also investigated: a reference (undeformed) case and a 10% static deformation case. In general, nutrient levels decreased moving away from the nutritional supply at the disc periphery. Minimum glucose levels were at the interface between the nucleus and annulus regions of the disc. Deformation caused a 6.2% decrease in the minimum glucose concentration in the normal IVD, while degeneration resulted in an 80% decrease. Although cell density was not affected in the undeformed normal disc, there was a decrease in cell

  3. Experimental model of intervertebral disc degeneration by needle puncture in Wistar rats

    PubMed Central

    Issy, A.C.; Castania, V.; Castania, M.; Salmon, C.E.G.; Nogueira-Barbosa, M.H.; Bel, E. Del; Defino, H.L.A.

    2013-01-01

    Animal models of intervertebral disc degeneration play an important role in clarifying the physiopathological mechanisms and testing novel therapeutic strategies. The objective of the present study is to describe a simple animal model of disc degeneration involving Wistar rats to be used for research studies. Disc degeneration was confirmed and classified by radiography, magnetic resonance and histological evaluation. Adult male Wistar rats were anesthetized and submitted to percutaneous disc puncture with a 20-gauge needle on levels 6-7 and 8-9 of the coccygeal vertebrae. The needle was inserted into the discs guided by fluoroscopy and its tip was positioned crossing the nucleus pulposus up to the contralateral annulus fibrosus, rotated 360° twice, and held for 30 s. To grade the severity of intervertebral disc degeneration, we measured the intervertebral disc height from radiographic images 7 and 30 days after the injury, and the signal intensity T2-weighted magnetic resonance imaging. Histological analysis was performed with hematoxylin-eosin and collagen fiber orientation using picrosirius red staining and polarized light microscopy. Imaging and histological score analyses revealed significant disc degeneration both 7 and 30 days after the lesion, without deaths or systemic complications. Interobserver histological evaluation showed significant agreement. There was a significant positive correlation between histological score and intervertebral disc height 7 and 30 days after the lesion. We conclude that the tail disc puncture method using Wistar rats is a simple, cost-effective and reproducible model for inducing disc degeneration. PMID:23532265

  4. The Involvement of Protease Nexin-1 (PN1) in the Pathogenesis of Intervertebral Disc (IVD) Degeneration

    PubMed Central

    Wu, Xinghuo; Liu, Wei; Duan, Zhenfeng; Gao, Yong; Li, Shuai; Wang, Kun; Song, Yu; Shao, Zengwu; Yang, Shuhua; Yang, Cao

    2016-01-01

    Protease nexin-1 (PN-1) is a serine protease inhibitor belonging to the serpin superfamily. This study was undertaken to investigate the regulatory role of PN-1 in the pathogenesis of intervertebral disk (IVD) degeneration. Expression of PN-1 was detected in human IVD tissue of varying grades. Expression of both PN-1 mRNA and protein was significantly decreased in degenerated IVD, and the expression levels of PN-1 were correlated with the grade of disc degeneration. Moreover, a decrease in PN-1 expression in primary NP cells was confirmed. On induction by IL-1β, the expression of PN-1 in NP cells was decreased at day 7, 14, and 21, as shown by western blot analysis and immunofluorescence staining. PN-1 administration decreased IL-1β-induced MMPs and ADAMTS production and the loss of Agg and Col II in NP cell cultures through the ERK1/2/NF-kB signaling pathway. The changes in PN-1 expression are involved in the pathogenesis of IVD degeneration. Our findings indicate that PN-1 administration could antagonize IL-1β-induced MMPs and ADAMTS, potentially preventing degeneration of IVD tissue. This study also revealed new insights into the regulation of PN-1 expression via the ERK1/2/NF-kB signaling pathway and the role of PN-1 in the pathogenesis of IVD degeneration. PMID:27460424

  5. Sodium and Potassium Currents Influence Wallerian Degeneration of Injured Drosophila Axons

    PubMed Central

    Mishra, Bibhudatta; Carson, Ross; Hume, Richard I.

    2013-01-01

    Axons degenerate after injury and in neuropathies and disease via a self-destruction program whose mechanism is poorly understood. Axons that have lost connection to their cell bodies have altered electrical and synaptic activities, but whether such changes play a role in the axonal degeneration process is not clear. We have used a Drosophila model to study the Wallerian degeneration of motoneuron axons and their neuromuscular junction synapses. We found that degeneration of the distal nerve stump after a nerve crush is greatly delayed when there is increased potassium channel activity (by overexpression of two different potassium channels, Kir2.1 and dORKΔ-C) or decreased voltage-gated sodium channel activity (using mutations in the para sodium channel). Conversely, degeneration is accelerated when potassium channel activity is decreased (by expressing a dominant-negative mutation of Shaker). Despite the effect of altering voltage-gated sodium and potassium channel activity, recordings made after nerve crush demonstrated that the distal stump does not fire action potentials. Rather, a variety of lines of evidence suggest that the sodium and potassium channels manifest their effects upon degeneration through changes in the resting membrane potential, which in turn regulates the level of intracellular free calcium within the isolated distal axon. PMID:24285879

  6. Potential Outcome Factors in Subacute Combined Degeneration

    PubMed Central

    Vasconcelos, Olavo M; Poehm, Erika H; McCarter, Robert J; Campbell, William W; Quezado, Zenaide M N

    2006-01-01

    BACKGROUND Subacute combined degeneration is an acquired myelopathy caused by vitamin B12 deficiency. Therapy with B12 leads to improvement in most but to complete recovery in only a few patients. Prognostic indicators in subacute combined degeneration are unknown; therefore, predicting complete recovery of neurologic deficits is challenging. PURPOSE To identify potential correlates of outcome and to generate hypotheses concerning predictors of complete resolution of neurologic deficits in subacute combined degeneration. DATA SOURCE We searched EMBASE (1974 to October 2005), MEDLINE (1968 to October 2005), and references from identified reports. REPORTS SELECTION Reports of patients with subacute combined degeneration containing results of magnetic resonance imaging (MRI) and description of outcome and 1 patient treated by the authors. DATA EXTRACTION, SYNTHESIS We extracted data from 45 reports and 57 patients (36 males, 21 females; age range: 10 to 81) with a diagnosis of subacute combined degeneration, and estimated the strength of association between clinical, laboratory, and radiological factors and complete resolution of signs and symptoms. RESULTS Eight patients (14%) achieved clinical resolution and 49 (86%) improved with B12 therapy. The absence of sensory dermatomal deficit, Romberg, and Babinski signs were associated with a higher complete resolution rate. Patients with MRI lesions in ≤7 segments and age less than 50 also appear to have higher rates of complete resolution. CONCLUSIONS B12 therapy is reported to stop progression and improve neurologic deficits in most patients with subacute combined degeneration. However, complete resolution only occurs in a small percentage of patients and appears to be associated with factors suggestive of less severe disease at the time of diagnosis. PMID:16970556

  7. Electromechanical probe and automated indentation maps are sensitive techniques in assessing early degenerated human articular cartilage.

    PubMed

    Sim, Sotcheadt; Chevrier, Anik; Garon, Martin; Quenneville, Eric; Lavigne, Patrick; Yaroshinsky, Alex; Hoemann, Caroline D; Buschmann, Michael D

    2016-06-09

    Recent advances in the development of new drugs to halt or even reverse the progression of Osteoarthritis at an early-stage requires new tools to detect early degeneration of articular cartilage. We investigated the ability of an electromechanical probe and an automated indentation technique to characterize entire human articular surfaces for rapid non-destructive discrimination between early degenerated and healthy articular cartilage. Human cadaveric asymptomatic articular surfaces (4 pairs of distal femurs and 4 pairs of tibial plateaus) were used. They were assessed ex vivo: macroscopically, electromechanically (maps of the electromechanical quantitative parameter, QP, reflecting streaming potentials), mechanically (maps of the instantaneous modulus, IM) and through cartilage thickness. Osteochondral cores were also harvested from healthy and degenerated regions for histological assessment, biochemical analyses and unconfined compression tests. The macroscopic visual assessment delimited three distinct regions on each articular surface: region I was macroscopically degenerated, region II was macroscopically normal but adjacent to region I and region III was the remaining normal articular surface. Thus, each extracted core was assigned to one of the three regions. A mixed effect model revealed that only the QP (p < 0.0001) and IM (p < 0.0001) were able to statistically discriminate the three regions. Effect size was higher for QP and IM than other assessments, indicating greater sensitivity to distinguish early degeneration of cartilage. When considering the mapping feature of the QP and IM techniques, it also revealed bilateral symmetry in a moderately similar distribution pattern between bilateral joints. This article is protected by copyright. All rights reserved.

  8. Potential role of retinal pigment epithelial lipofuscin accumulation in age-related macular degeneration.

    PubMed

    Katz, Martin L

    2002-01-01

    Age-related macular degeneration (AMD) is a leading cause of severe visual impairment in developed countries. The vision loss associated with AMD is the result of degenerative changes in the central region of the retina called the macula. Maintenance of normal structure and function of the macular retina, and of the remainder of the retina as well, is critically dependent on the supporting role of the adjacent retinal pigment epithelium (RPE). Impairment of normal RPE functions is known to result in retinal degeneration and loss of visual function. Thus, it has been hypothesized that the retinal degeneration that characterizes AMD is secondary to age-related deterioration in RPE support functions. Like many other postmitotic cell types, the RPE accumulates autofluorescent lysosomal storage bodies (lipofuscin) during senescence. In human eyes, lipofuscin comes to occupy a substantial fraction of the RPE cytoplasmic volume in the elderly. Does this lipofuscin accumulation contribute to the development of AMD? This question is a specific case of the broader question of whether lipofuscin accumulation in general is detrimental to cells. Unfortunately, definitive data do not exist to allow these questions to be answered. Although a correlation between RPE lipofuscin content and AMD has been reported, a cause-and-effect relationship between RPE lipofuscin accumulation and the development of this disease has not been established. It has been reported that a mutation in a gene encoding a photoreceptor-specific protein results in massive RPE lipofuscin accumulation and early-onset macular degeneration. However, again the accelerated RPE lipofuscin accumulation has not been shown to be the cause of the accompanying macular degeneration. The lack of a definitive link between RPE lipofuscin accumulation and AMD illustrates one of the biggest challenges remaining in lipofuscin research-determining whether lipofuscin accumulation per se has an impact on cell function.

  9. Frontotemporal Lobar Degeneration and MicroRNAs

    PubMed Central

    Piscopo, Paola; Albani, Diego; Castellano, Anna E.; Forloni, Gianluigi; Confaloni, Annamaria

    2016-01-01

    Frontotemporal lobar degeneration (FTLD) includes a spectrum of disorders characterized by changes of personality and social behavior and, often, a gradual and progressive language dysfunction. In the last years, several efforts have been fulfilled in identifying both genetic mutations and pathological proteins associated with FTLD. The molecular bases undergoing the onset and progression of the disease remain still unknown. Recent literature prompts an involvement of RNA metabolism in FTLD, particularly microRNAs (miRNAs). Dysregulation of miRNAs in several disorders, including neurodegenerative diseases, and increasing importance of circulating miRNAs in different pathologies has suggested to implement the study of their possible application as biological markers and new therapeutic targets; moreover, miRNA-based therapy is becoming a powerful tool to deepen the function of a gene, the mechanism of a disease, and validate therapeutic targets. Regarding FTLD, different studies showed that miRNAs are playing an important role. For example, several reports have evaluated miRNA regulation of the progranulin gene suggesting that it is under their control, as described for miR-29b, miR-107, and miR-659. More recently, it has been demonstrated that TMEM106B gene, which protein is elevated in FTLD-TDP brains, is repressed by miR-132/212 cluster; this post-transcriptional mechanism increases intracellular levels of progranulin, affecting its pathways. These findings if confirmed could suggest that these microRNAs have a role as potential targets for some related-FTLD genes. In this review, we focus on the emerging roles of the miRNAs in the pathogenesis of FTLD. PMID:26903860

  10. CT of sarcomatous degeneration in neurofibromatosis

    SciTech Connect

    Coleman, B.G.; Arger, P.H.; Dalinka, M.K.; Obringer, A.C.; Raney, B.R.; Meadows, A.T.

    1983-02-01

    Neurofibromatosis is a relatively common disorder that often involves many organ systems. One of the least understood aspects of this malady is a well documented potential for sarcomatous degeneration of neurofibromas. The inability to identify patients at risk and the lack of noninvasive screening methods for symptomatic patients often leads to late diagnosis. In six of seven subsequently proven neurofibrosarcomas, CT demonstrated low-density areas that histopathologically appeared to be due to necrosis, hemorrhage, and/or cystic degeneration. The density differences within these sarcomas were enhanced by the intravenous adminstration of iodinated contrast agents.

  11. Pathogenesis of tendinopathies: inflammation or degeneration?

    PubMed Central

    Abate, Michele; Gravare-Silbernagel, Karin; Siljeholm, Carl; Di Iorio, Angelo; De Amicis, Daniele; Salini, Vincenzo; Werner, Suzanne; Paganelli, Roberto

    2009-01-01

    The intrinsic pathogenetic mechanisms of tendinopathies are largely unknown and whether inflammation or degeneration has the prominent role is still a matter of debate. Assuming that there is a continuum from physiology to pathology, overuse may be considered as the initial disease factor; in this context, microruptures of tendon fibers occur and several molecules are expressed, some of which promote the healing process, while others, including inflammatory cytokines, act as disease mediators. Neural in-growth that accompanies the neovessels explains the occurrence of pain and triggers neurogenic-mediated inflammation. It is conceivable that inflammation and degeneration are not mutually exclusive, but work together in the pathogenesis of tendinopathies. PMID:19591655

  12. [New aspects in age related macular degeneration].

    PubMed

    Turlea, C

    2012-01-01

    Being the leading cause of blindness in modern world Age Related Macular Degeneration has beneficiated in the last decade of important progress in diagnosis, classification and the discovery of diverse factors who contribute to the etiology of this disease. Treatments have arised who can postpone the irreversible evolution of the disease and thus preserve vision. Recent findings have identified predisposing genetic factors and also inflamatory and imunological parameters that can be modified trough a good and adequate prevention and therapy This articole reviews new aspects of patology of Age Related Macular Degeneration like the role of complement in maintaining inflamation and the role of oxidative stress on different structures of the retina.

  13. Stability control in underground working adjacent an in situ oil shale retort

    SciTech Connect

    Ricketts, Th. E.

    1985-07-30

    In situ oil shale retorts are formed in spaced-apart rows, with adjacent rows of such retorts being separated by load-bearing inter-retort pillars of unfragmented formation sufficiently strong for preventing substantial subsidence. Each retort contains a fragmented permeable mass of formation particles containing oil shale. An air level drift is excavated in formation directly above the inter-retort pillar so that the roof and/or floor of the air level drift is spaced above the upper boundaries of the retorts in such adjacent rows. This causes the roof of the air level drift to be in compression, rather than in tension, which stabilizes the roof and avoids dangerous rock falls. During retorting operations, air is introduced at the upper edge of each retort through lateral air inlet passages sloping downwardly from the air level drift. Off gas and liquid products are withdrawn from each retort through a production level passage at the bottom of each report at the edge opposite the air inlet. The production level passages connect to a main production level drift extending between adjacent rows of retors. The roof of the main production level drift is excavated in fgormation directly below the inter-retort pillar so that the roof of of the production level drift is spaced below the lower boundaries of the retorts in adjacent rows. This places the roof of the production level drift in compression, avoiding the likelihood of rock falls.

  14. Simulation of the Progression of Intervertebral Disc Degeneration due to Decreased Nutrition Supply

    PubMed Central

    Gu, Weiyong; Zhu, Qiaoqiao; Gao, Xin; Brown, Mark D.

    2014-01-01

    Study Design Simulate the progression of human disc degeneration. Objective The objective of this study was to quantitatively analyze and simulate the changes in cell density, nutrition level, proteoglycan content, water content, and volume change during human disc degeneration using a numerical method. Summary of Background Data Understanding the etiology and progression of intervertebral disc (IVD) degeneration is crucial for developing effective treatment strategies for IVD-degeneration related diseases. During tissue degeneration, the disc undergoes losses of cell viability and activities, changes in extracellular matrix composition and structure, and compromise of the tissue-level integrity and function, which is significantly influenced by the inter-coupled biological, chemical, electrical, and mechanical signals in the disc. Characterizing these signals in human discs in vivo is difficult. Methods A realistic 3D finite element model of the human IVD was developed based on biomechano-electrochemical continuum mixture theory. The theoretical framework and the constitutive relationships were all biophysics based. All the material properties were obtained from experimental results. The cell-mediated disc degeneration process caused by lowered nutrition levels at disc boundaries was simulated and validated by comparing with experimental results. Results Cell density reached equilibrium state in 30 days after reduced nutrition supply at the disc boundary, while the proteoglycan (PG) and water contents reached a new equilibrium state in 55 years. The simulated results for the distributions of PG and water contents within the disc were consistent with the results measured in the literature, except for the distribution of PG content in the sagittal direction. Conclusions Poor nutrition supply has a long-term effect on disc degeneration. PMID:25188596

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

    PubMed Central

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

    2015-01-01

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

  16. 30 CFR 56.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  17. 30 CFR 57.9103 - Clearance on adjacent tracks.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  18. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

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

  19. 49 CFR 236.404 - Signals at adjacent control points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

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

  20. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  1. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  2. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  3. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  4. 33 CFR 80.1395 - Puget Sound and adjacent waters.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  5. Phospholipase A2 inhibitors protect against prion and Aβ mediated synapse degeneration

    PubMed Central

    2010-01-01

    Background An early event in the neuropathology of prion and Alzheimer's diseases is the loss of synapses and a corresponding reduction in the level of synaptophysin, a pre-synaptic membrane protein essential for neurotransmission. The molecular mechanisms involved in synapse degeneration in these diseases are poorly understood. In this study the process of synapse degeneration was investigated by measuring the synaptophysin content of cultured neurones incubated with the prion derived peptide (PrP82-146) or with Aβ1-42, a peptide thought to trigger pathogenesis in Alzheimer's disease. A pharmacological approach was used to screen cell signalling pathways involved in synapse degeneration. Results Pre-treatment with phospholipase A2 inhibitors (AACOCF3, MAFP and aristolochic acids) protected against synapse degeneration in cultured cortical and hippocampal neurones incubated with PrP82-146 or Aβ1-42. Synapse degeneration was also observed following the addition of a specific phospholipase A2 activating peptide (PLAP) and the addition of PrP82-146 or Aβ1-42 activated cytoplasmic phospholipase A2 within synapses. Activation of phospholipase A2 is the first step in the generation of platelet-activating factor (PAF) and PAF receptor antagonists (ginkgolide B, Hexa-PAF and CV6029) protected against synapse degeneration induced by PrP82-146, Aβ1-42 and PLAP. PAF facilitated the production of prostaglandin E2, which also caused synapse degeneration and pre-treatment with the prostanoid E receptor antagonist AH13205 protected against PrP82-146, Aβ1-42 and PAF induced synapse degeneration. Conclusions Our results are consistent with the hypothesis that PrP82-146 and Aβ1-42trigger abnormal activation of cytoplasmic phospholipase A2 resident within synapses, resulting in elevated levels of PAF and prostaglandin E2that cause synapse degeneration. Inhibitors of this pathway that can cross the blood brain barrier may protect against the synapse degeneration seen during

  6. Pseudotumoral encapsulated fat necrosis with diffuse pseudomembranous degeneration.

    PubMed

    Felipo, F; Vaquero, M; del Agua, C

    2004-09-01

    An extraordinary case of encapsulated fat necrosis characterized by its large size, diffuse formation of pseudomembranes, and tendency to recur after excision is reported. A 67-year-old Caucasian woman suffering from morbid obesity was admitted for diagnosis and surgical treatment of a soft tissue mass showing a longest diameter of 14 cm and lying adjacently to the scar from previous appendicectomy. Histopathologic features were consistent with a nodular-cystic encapsulated fat necrosis with diffuse pseudomembranous transformation. Eight months after surgery, a new larger mass (longest diameter of 18 cm) sharing identical histopathologic features appeared in the same location. Encapsulated fat necrosis is a well-defined entity even though several names have been proposed for this condition, including mobile encapsulated lipoma, encapsulated necrosis, or nodular-cystic fat necrosis. Its pathogenesis seems to be related to ischemic changes secondary to previous trauma. It may occasionally show degenerative changes, including dystrophic calcifications and presence of pseudomembranes. To our knowledge, these are the first reported cases of encapsulated fat necrosis presenting as lesions of such size and showing diffuse formation of pseudomembranes; these particular features made diagnosis difficult and led to consideration of a wide range of potential diagnostic possibilities. This case expands the clinico-pathologic spectrum of membranocystic fat necrosis, including the potential ability of this subcutaneous fatty tissue abnormality to recur after surgical excision. Felipo F, Vaquero M, del Agua C. Pseudotumoral encapsulated fat necrosis with diffuse pseudomembranous degeneration.

  7. Degenerate target sites mediate rapid primed CRISPR adaptation.

    PubMed

    Fineran, Peter C; Gerritzen, Matthias J H; Suárez-Diez, María; Künne, Tim; Boekhorst, Jos; van Hijum, Sacha A F T; Staals, Raymond H J; Brouns, Stan J J

    2014-04-22

    Prokaryotes encode adaptive immune systems, called CRISPR-Cas (clustered regularly interspaced short palindromic repeats-CRISPR associated), to provide resistance against mobile invaders, such as viruses and plasmids. Host immunity is based on incorporation of invader DNA sequences in a memory locus (CRISPR), the formation of guide RNAs from this locus, and the degradation of cognate invader DNA (protospacer). Invaders can escape type I-E CRISPR-Cas immunity in Escherichia coli K12 by making point mutations in the seed region of the protospacer or its adjacent motif (PAM), but hosts quickly restore immunity by integrating new spacers in a positive-feedback process termed "priming." Here, by using a randomized protospacer and PAM library and high-throughput plasmid loss assays, we provide a systematic analysis of the constraints of both direct interference and subsequent priming in E. coli. We have defined a high-resolution genetic map of direct interference by Cascade and Cas3, which includes five positions of the protospacer at 6-nt intervals that readily tolerate mutations. Importantly, we show that priming is an extremely robust process capable of using degenerate target regions, with up to 13 mutations throughout the PAM and protospacer region. Priming is influenced by the number of mismatches, their position, and is nucleotide dependent. Our findings imply that even outdated spacers containing many mismatches can induce a rapid primed CRISPR response against diversified or related invaders, giving microbes an advantage in the coevolutionary arms race with their invaders.

  8. Stress Wave Interaction Between Two Adjacent Blast Holes

    NASA Astrophysics Data System (ADS)

    Yi, Changping; Johansson, Daniel; Nyberg, Ulf; Beyglou, Ali

    2016-05-01

    Rock fragmentation by blasting is determined by the level and state of stress in the rock mass subjected to blasting. With the application of electronic detonators, some researchers stated that it is possible to achieve improved fragmentation through stress wave superposition with very short delay times. This hypothesis was studied through theoretical analysis in the paper. First, the stress in rock mass induced by a single-hole shot was analyzed with the assumptions of infinite velocity of detonation and infinite charge length. Based on the stress analysis of a single-hole shot, the stress history and tensile stress distribution between two adjacent holes were presented for cases of simultaneous initiation and 1 ms delayed initiation via stress superposition. The results indicated that the stress wave interaction is local around the collision point. Then, the tensile stress distribution at the extended line of two adjacent blast holes was analyzed for a case of 2 ms delay. The analytical results showed that the tensile stress on the extended line increases due to the stress wave superposition under the assumption that the influence of neighboring blast hole on the stress wave propagation can be neglected. However, the numerical results indicated that this assumption is unreasonable and yields contrary results. The feasibility of improving fragmentation via stress wave interaction with precise initiation was also discussed. The analysis in this paper does not support that the interaction of stress waves improves the fragmentation.

  9. Central cornea involvement in Terrien's degeneration.

    PubMed

    Nirankari, V S; Kelman, S E; Richards, R D

    1983-03-01

    A 15-year-old female showed classical signs of Terrien's corneal degeneration including peripheral corneal thinning, vascularization, lipid deposition, and ectasia. She also showed episodes of conjunctival inflammation and perforation following minor trauma, all in the presence of an intact epithelium. She also showed progressive central corneal thinning and opacification, features not reported in the literature in the last 30 years.

  10. Retinal remodeling in inherited photoreceptor degenerations.

    PubMed

    Marc, Robert E; Jones, Bryan W

    2003-10-01

    Photoreceptor degenerations initiated in rods or the retinal pigmented epithelium usually evoke secondary cone death and sensory deafferentation of the surviving neural retina. In the mature central nervous system, deafferentation evokes atrophy and connective re-patterning. It has been assumed that the neural retina does not remodel, and that it is a passive survivor. Screening of advanced stages of human and rodent retinal degenerations with computational molecular phenotyping has exposed a prolonged period of aggressive negative remodeling in which neurons migrate along aberrant glial columns and seals, restructuring the adult neural retina (1). Many neurons die, but survivors rewire the remnant inner plexiform layer (IPL), forming thousands of novel ectopic microneuromas in the remnant inner nuclear layer (INL). Bipolar and amacrine cells engage in new circuits that are most likely corruptive. Remodeling in human and rodent retinas emerges regardless of the molecular defects that initially trigger retinal degenerations. Although remodeling may constrain therapeutic intervals for molecular, cellular, or bionic rescue, the exposure of intrinsic retinal remodeling by the removal of sensory control in retinal degenerations suggests that neuronal organization in the normal retina may be more plastic than previously believed.

  11. Retinal remodeling triggered by photoreceptor degenerations.

    PubMed

    Jones, Bryan W; Watt, Carl B; Frederick, Jeanne M; Baehr, Wolfgang; Chen, Ching-Kang; Levine, Edward M; Milam, Ann H; Lavail, Matthew M; Marc, Robert E

    2003-09-08

    Many photoreceptor degenerations initially affect rods, secondarily leading to cone death. It has long been assumed that the surviving neural retina is largely resistant to this sensory deafferentation. New evidence from fast retinal degenerations reveals that subtle plasticities in neuronal form and connectivity emerge early in disease. By screening mature natural, transgenic, and knockout retinal degeneration models with computational molecular phenotyping, we have found an extended late phase of negative remodeling that radically changes retinal structure. Three major transformations emerge: 1) Müller cell hypertrophy and elaboration of a distal glial seal between retina and the choroid/retinal pigmented epithelium; 2) apparent neuronal migration along glial surfaces to ectopic sites; and 3) rewiring through evolution of complex neurite fascicles, new synaptic foci in the remnant inner nuclear layer, and new connections throughout the retina. Although some neurons die, survivors express molecular signatures characteristic of normal bipolar, amacrine, and ganglion cells. Remodeling in human and rodent retinas is independent of the initial molecular targets of retinal degenerations, including defects in the retinal pigmented epithelium, rhodopsin, or downstream phototransduction elements. Although remodeling may constrain therapeutic intervals for molecular, cellular, or bionic rescue, it suggests that the neural retina may be more plastic than previously believed.

  12. Driving and Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Owsley, Cynthia; McGwin, Gerald, Jr.

    2008-01-01

    This article reviews the research literature on driving and age-related macular degeneration, which is motivated by the link between driving and the quality of life of older adults and their increased collision rate. It addresses the risk of crashes, driving performance, driving difficulty, self-regulation, and interventions to enhance, safety,…

  13. Single Degenerate Progenitors of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Bours, Madelon; Toonen, Silvia; Nelemans, Gijs

    2013-01-01

    There is a general agreement that Type Ia supernovae correspond to the thermonuclear runaway of a white dwarf (WD) in a compact binary. The details of these progenitor systems are still unclear. Using the population synthesis code SeBa and several assumption for the WD retention efficiency, we estimate the delay times and supernova rates for the single degenerate scenario.

  14. Intervertebral disk degeneration and emerging biologic treatments.

    PubMed

    Kepler, Christopher K; Anderson, D Greg; Tannoury, Chadi; Ponnappan, Ravi K

    2011-09-01

    Although understanding of the biologic basis of intervertebral disk (IVD) degeneration is rapidly advancing, the unique IVD environment presents challenges to the development and delivery of biologic treatments. Acceleration of cellular senescence and apoptosis in degenerative IVDs and the depletion of matrix proteins have prompted the development of treatments based on replacing IVD cells using various cell sources. However, this strategy has not been tested in animal models. IVD degeneration and associated pain have led to interest in pathologic innervation of the IVD and ultimately to the development of percutaneous devices to ablate afferent nerve endings in the posterior annulus. Degeneration leads to changes in the expression of matrix protein, cytokines, and proteinases. Injection of growth factors and mitogens may help overcome these degenerative changes in IVD phenotype, and these potential treatments are being explored in animal studies. Gene therapy is an elegant method to address changes in protein expression, but efforts to apply this technology to IVD degeneration are still at early stages.

  15. Depression in Age-Related Macular Degeneration

    ERIC Educational Resources Information Center

    Casten, Robin; Rovner, Barry

    2008-01-01

    Age-related macular degeneration (AMD) is a major cause of disability in the elderly, substantially degrades the quality of their lives, and is a risk factor for depression. Rates of depression in AMD are substantially greater than those found in the general population of older people, and are on par with those of other chronic and disabling…

  16. Nonunital Spectral Triples Associated to Degenerate Metrics

    NASA Astrophysics Data System (ADS)

    Rennie, A.

    We show that one can define (p,∞)-summable spectral triples using degenerate metrics on smooth manifolds. Furthermore, these triples satisfy Connes-Moscovici's discrete and finite dimension spectrum hypothesis, allowing one to use the Local Index Theorem [1] to compute the pairing with K-theory. We demonstrate this with a concrete example.

  17. Ecological transition predictably associated with gene degeneration.

    PubMed

    Wessinger, Carolyn A; Rausher, Mark D

    2015-02-01

    Gene degeneration or loss can significantly contribute to phenotypic diversification, but may generate genetic constraints on future evolutionary trajectories, potentially restricting phenotypic reversal. Such constraints may manifest as directional evolutionary trends when parallel phenotypic shifts consistently involve gene degeneration or loss. Here, we demonstrate that widespread parallel evolution in Penstemon from blue to red flowers predictably involves the functional inactivation and degeneration of the enzyme flavonoid 3',5'-hydroxylase (F3'5'H), an anthocyanin pathway enzyme required for the production of blue floral pigments. Other types of genetic mutations do not consistently accompany this phenotypic shift. This pattern may be driven by the relatively large mutational target size of degenerative mutations to this locus and the apparent lack of associated pleiotropic effects. The consistent degeneration of F3'5'H may provide a mechanistic explanation for the observed asymmetry in the direction of flower color evolution in Penstemon: Blue to red transitions are common, but reverse transitions have not been observed. Although phenotypic shifts in this system are likely driven by natural selection, internal constraints may generate predictable genetic outcomes and may restrict future evolutionary trajectories.

  18. Cell therapy for the degenerating intervertebral disc.

    PubMed

    Tong, Wei; Lu, Zhouyu; Qin, Ling; Mauck, Robert L; Smith, Harvey E; Smith, Lachlan J; Malhotra, Neil R; Heyworth, Martin F; Caldera, Franklin; Enomoto-Iwamoto, Motomi; Zhang, Yejia

    2017-03-01

    Spinal conditions related to intervertebral disc (IVD) degeneration cost billions of dollars in the US annually. Despite the prevalence and soaring cost, there is no specific treatment that restores the physiological function of the diseased IVD. Thus, it is vital to develop new treatment strategies to repair the degenerating IVD. Persons with IVD degeneration without back pain or radicular leg pain often do not require any intervention. Only patients with severe back pain related to the IVD degeneration or biomechanical instability are likely candidates for cell therapy. The IVD progressively degenerates with age in humans, and strategies to repair the IVD depend on the stage of degeneration. Cell therapy and cell-based gene therapy aim to address moderate disc degeneration; advanced stage disease may require surgery. Studies involving autologous, allogeneic, and xenogeneic cells have all shown good survival of these cells in the IVD, confirming that the disc niche is an immunologically privileged site, permitting long-term survival of transplanted cells. All of the animal studies reviewed here reported some improvement in disc structure, and 2 studies showed attenuation of local inflammation. Among the 50 studies reviewed, 25 used some type of scaffold, and cell leakage is a consistently noted problem, though some studies showed reduced cell leakage. Hydrogel scaffolds may prevent cell leakage and provide biomechanical support until cells can become established matrix producers. However, these gels need to be optimized to prevent this leakage. Many animal models have been leveraged in this research space. Rabbit is the most frequently used model (28 of 50), followed by rat, pig, and dog. Sheep and goat IVDs resemble those of humans in size and in the absence of notochordal cells. Despite this advantage, there were only 2 sheep and 1 goat studies of 50 studies in this cohort. It is also unclear if a study in large animals is needed before clinical trials since

  19. Terminal arbor degeneration (TAD): a novel lesion produced by the antineoplastic agent, paclitaxel

    PubMed Central

    Bennett, Gary J.; Liu, Guo Kai; Xiao, Wen Hua; Jin, Hai Wei; Siau, Chiang

    2011-01-01

    The anti-neoplastic agent, paclitaxel, causes a dose-limiting distal, symmetrical, sensory peripheral neuropathy that is often accompanied by a neuropathic pain syndrome. In a low-dose model of paclitaxel-evoked painful peripheral neuropathy in the rat, we have shown that the drug causes degeneration of intraepidermal nerve fibers (IENFs), i.e., the fibers which give rise to the sensory afferent’s terminal receptor arbour. However, we did not find any evidence for axonal degeneration in samples taken at the mid-nerve level. Here we aimed to determine whether the absence of degenerating peripheral nerve axons was due to sampling a level that was too proximal. We used electron microscopy to study the distal-most branches of the nerves innervating the hind paw glabrous skin of normal and paclitaxel-treated rats. We confirmed that we sampled at a time when IENF degeneration was prominent. Because degeneration might be easier to detect with higher paclitaxel doses, we examined a four-fold cumulative dose range (8–32 mg/kg). We found no evidence of degeneration in the superficial subepidermal axon bundles (sSAB) that are located just a few microns below the epidermal basal lamina. Specifically, for all three dose groups there was no change in the number of sSAB per mm of epidermal border, no change in the number of axons per sSAB, and no change in the diameter of sSAB axons. We conclude that paclitaxel produces a novel type of lesion that is restricted to the afferent axon’s terminal arbor; we name this lesion “terminal arbor degeneration (TAD)”. PMID:21395870

  20. Herb formula "Fufangqishe-Pill" prevents upright posture-induced intervertebral disc degeneration at the lumbar in rats.

    PubMed

    Liang, Qian-Qian; Xi, Zhi-Jie; Bian, Qin; Cui, Xue-Jun; Li, Chen-Guang; Hou, Wei; Shi, Qi; Wang, Yong-Jun

    2010-01-01

    Degeneration of the lumbar spine plays an important role in most chronic low back pain. Prevention of lumbar intervertebral disc (IVD) degeneration is therefore a high research priority. Both our previous multicenter clinical trials and pharmacological research showed that Fufangqishe-Pill (FFQSP), a newly patented traditional Chinese medicine, could effectively relieve the symptoms of neck pain and prevent cervical degeneration. To clarify the effect of FFQSP on lumbar IVD degeneration, we applied a lumbar IVD degeneration rat model induced by prolonged upright posture. Pretreatment of FFQSP for one month prevented the histological changes indicating IVD disorganization; increased type II-collagen level, decreased type X-collagen protein level, and increased Col2alpha1 mRNA expression at all time points; and decreased Col10alpha1, matrix metalloproteinase (MMP)-3, MMP13, and Interleukin (IL)-1beta mRNA expression induced by upright posture for 7 and 9 months. These results suggest that FFQSP prevents lumbar IVD degeneration induced by upright posture. FFQSP is a promising medicine for lumbar IVD degeneration disease.

  1. Localization of Drosophila retinal degeneration B, a membrane- associated phosphatidylinositol transfer protein

    PubMed Central

    1993-01-01

    The Drosophila retinal degeneration B (rdgB) mutation causes abnormal photoreceptor response and light-enhanced retinal degeneration. Immunoblots using polyclonal anti-rdgB serum showed that rdgB is a 160- kD membrane protein. The antiserum localized the rdgB protein in photoreceptors, antennae, and regions of the Drosophila brain, indicating that the rdgB protein functions in many sensory and neuronal cells. In photoreceptors, the protein localized adjacent to the rhabdomeres, in the vicinity of the subrhabdomeric cisternae. The rdgB protein's amino-terminal 281 residues are > 40% identical to the rat brain phosphatidylinositol transfer protein (PI-TP). A truncated rdgB protein, which contains only this amino-terminal domain, possesses a phosphatidylinositol transfer activity in vitro. The remaining 773 carboxyl terminal amino acids have additional functional domains. Nitrocellulose overlay experiments reveal that an acidic amino acid domain, adjacent to the PI transfer domain, binds 45Ca+2. Six hydrophobic segments are found in the middle of the putative translation product and likely function as membrane spanning domains. These results suggest that the rdgB protein, unlike the small soluble PI-TPs, is a membrane-associated PI-TP, which may be directly regulated by light-induced changes in intracellular calcium. PMID:8354691

  2. FAIM-L regulation of XIAP degradation modulates Synaptic Long-Term Depression and Axon Degeneration

    PubMed Central

    Martínez-Mármol, Ramón; Barneda-Zahonero, Bruna; Soto, David; Andrés, Rosa Maria; Coccia, Elena; Gasull, Xavier; Planells-Ferrer, Laura; Moubarak, Rana S.; Soriano, Eduardo; Comella, Joan X.

    2016-01-01

    Caspases have recently emerged as key regulators of axonal pruning and degeneration and of long-term depression (LTD), a long-lasting form of synaptic plasticity. However, the mechanism underlying these functions remains unclear. In this context, XIAP has been shown to modulate these processes. The neuron-specific form of FAIM protein (FAIM-L) is a death receptor antagonist that stabilizes XIAP protein levels, thus preventing death receptor-induced neuronal apoptosis. Here we show that FAIM-L modulates synaptic transmission, prevents chemical-LTD induction in hippocampal neurons, and thwarts axon degeneration after nerve growth factor (NGF) withdrawal. Additionally, we demonstrate that the participation of FAIM-L in these two processes is dependent on its capacity to stabilize XIAP protein levels. Our data reveal FAIM-L as a regulator of axonal degeneration and synaptic plasticity. PMID:27767058

  3. Effect of disc degeneration on the muscle recruitment pattern in upright posture: a computational analysis.

    PubMed

    Kim, Young Eun; Choi, Hae Won

    2015-01-01

    Based on the sensor driving control mechanism model, the effect of disc degeneration on the trunk muscle recruitment (TMR) pattern was analysed in erect standing posture. A previously developed computational model was used for this analysis, with modifications incorporating the T12-L1 motion segment and additional muscle fascicles. To generate disc degeneration at three different levels (L3-L4, L4-L5, or L5-S1), the material properties of the ground matrix of the annulus and bulk modulus of the nucleus were reduced. The finite element method combined with an optimization technique was applied to calculate the muscle forces. Minimization of deviations in the averaged tensile stress in the annulus fibres at the outermost layer in the five discs was selected for muscle force calculations. The results indicated that the disc degeneration noticeably increased the activation of the superficial muscle (IT and R) even though there was no clear change in the longissimus thoracis. Unlike some of the superficial muscles, activation in the deep muscles (multifidus (ML, MS, MT), LL and Q) was decreased. The change in TMR pattern generated an intervertebral disc angle difference and nucleus pressure increased in the upper level. These differences are expected to be functional in that they reduce the stress at the degenerated disc by changing the muscle activation, which slows down the progress of disc degeneration.

  4. Impaired Mitochondrial Energy Production Causes Light-Induced Photoreceptor Degeneration Independent of Oxidative Stress.

    PubMed

    Jaiswal, Manish; Haelterman, Nele A; Sandoval, Hector; Xiong, Bo; Donti, Taraka; Kalsotra, Auinash; Yamamoto, Shinya; Cooper, Thomas A; Graham, Brett H; Bellen, Hugo J

    2015-07-01

    Two insults often underlie a variety of eye diseases including glaucoma, optic atrophy, and retinal degeneration--defects in mitochondrial function and aberrant Rhodopsin trafficking. Although mitochondrial defects are often associated with oxidative stress, they have not been linked to Rhodopsin trafficking. In an unbiased forward genetic screen designed to isolate mutations that cause photoreceptor degeneration, we identified mutations in a nuclear-encoded mitochondrial gene, ppr, a homolog of human LRPPRC. We found that ppr is required for protection against light-induced degeneration. Its function is essential to maintain membrane depolarization of the photoreceptors upon repetitive light exposure, and an impaired phototransduction cascade in ppr mutants results in excessive Rhodopsin1 endocytosis. Moreover, loss of ppr results in a reduction in mitochondrial RNAs, reduced electron transport chain activity, and reduced ATP levels. Oxidative stress, however, is not induced. We propose that the reduced ATP level in ppr mutants underlies the phototransduction defect, leading to increased Rhodopsin1 endocytosis during light exposure, causing photoreceptor degeneration independent of oxidative stress. This hypothesis is bolstered by characterization of two other genes isolated in the screen, pyruvate dehydrogenase and citrate synthase. Their loss also causes a light-induced degeneration, excessive Rhodopsin1 endocytosis and reduced ATP without concurrent oxidative stress, unlike many other mutations in mitochondrial genes that are associated with elevated oxidative stress and light-independent photoreceptor demise.

  5. Reduced phosphoCREB in Müller glia during retinal degeneration in rd10 mice

    PubMed Central

    Bachleda, Amelia; Xiong, Yubin; Osawa, Shoji; Weiss, Ellen R.

    2017-01-01

    Purpose The mechanisms that trigger retinal degeneration are not well understood, despite the availability of several animal models with different mutations. In the present report, the rd10 mouse, a model for retinitis pigmentosa (RP) that contains a mutation in the gene for PDE6β (Pde6b), is used to evaluate gliosis, as a marker for retinal stress, and cyclic AMP response element binding protein (CREB) phosphorylation, which may be important early in retinal degeneration. Methods Wild-type C57Bl6J and rd10 mice raised under cyclic light were examined for changes in gliosis and CREB phosphorylation for approximately 3 weeks beginning at P14 to P17 using immunocytochemistry. Mice raised under normal cyclic light and in complete darkness were also compared for changes in CREB phosphorylation. Results Gliosis in rd10 mice raised under cyclic light was apparent at P17, before extensive degeneration of the photoreceptor layer is visible, and increased over time. Phosphorylation of CREB at Ser133 (pCREB) was detected in Müller glia (MG) in the wild-type and rd10 mice. However, at all phases of photoreceptor degeneration, the pCREB levels were lower in the rd10 mice. We also observed extensive migration of MG cell bodies to the outer nuclear layer (ONL) during degeneration. In contrast to the mice raised under cyclic light, the rd10 mice raised in the dark exhibited slower rates of degeneration. When the dark-reared mice were exposed to cyclic light, the photoreceptor layer degenerated within 4 days to approximately one to two rows of nuclei. Interestingly, the pCREB levels in the MG also decreased during this 4-day cyclic light exposure compared to the levels in the rd10 mice raised continuously in the dark. Conclusions The results of these studies suggest that photoreceptors communicate directly or indirectly with MG at early stages, inducing gliosis before extensive retinal degeneration is apparent in rd10 mice. Surprisingly, phosphorylation of CREB is downregulated

  6. Mutations in KCNJ13 Cause Autosomal-Dominant Snowflake Vitreoretinal Degeneration

    PubMed Central

    Hejtmancik, J. Fielding; Jiao, Xiaodong; Li, Anren; Sergeev, Yuri V.; Ding, Xiaoyan; Sharma, Anil K.; Chan, Chi-Chao; Medina, Igor; Edwards, Albert O.

    2008-01-01

    Snowflake vitreoretinal degeneration (SVD, MIM 193230) is a developmental and progressive hereditary eye disorder that affects multiple tissues within the eye. Diagnostic features of SVD include fibrillar degeneration of the vitreous humor, early-onset cataract, minute crystalline deposits in the neurosensory retina, and retinal detachment. A genome-wide scan previously localized the genetic locus for SVD to a 20 Mb region flanked by D2S2158 and D2S2202. This region contains 59 genes, of which 20 were sequenced, disclosing a heterozygous mutation (484C > T, R162W) in KCNJ13, member 13 of subfamily J of the potassium inwardly rectifying channel family in all affected individuals. The mutation in KCNJ13, the gene encoding Kir7.1, was not present in unaffected family members and 210 control individuals. Kir7.1 localized to human retina and retinal pigment epithelium and was especially prevalent in the internal limiting membrane adjacent to the vitreous body. Molecular modeling of this mutation predicted disruption of the structure of the potassium channel in the closed state located immediately adjacent to the cell-membrane inner boundary. Functionally, unlike wild-type Kir7.1 whose overexpression in CHO-K1 cells line produces highly selective potassium current, overexpression of R162W mutant Kir7.1 produces a nonselective cation current that depolarizes transfected cells and increases their fragility. These results indicate that the KCNJ13 R162W mutation can cause SVD and further show that vitreoretinal degeneration can arise through mutations in genes whose products are not structural components of the vitreous. PMID:18179896

  7. The role of epigenetics in age-related macular degeneration.

    PubMed

    Gemenetzi, M; Lotery, A J

    2014-12-01

    It is becoming increasingly evident that epigenetic mechanisms influence gene expression and can explain how interactions between genetics and the environment result in particular phenotypes during development. The extent to which this epigenetic effect contributes to phenotype heritability in age-related macular degeneration (AMD) is currently ill defined. However, emerging evidence suggests that epigenetic changes are relevant to AMD and as such provide an exciting new avenue of research for AMD. This review addresses information on the impact of posttranslational modification of the genome on the pathogenesis of AMD, such as DNA methylation changes affecting antioxidant gene expression, hypoxia-regulated alterations in chromatin structure, and histone acetylation status in relation to angiogenesis and inflammation. It also contains information on the role of non-coding RNA-mediated gene regulation in AMD at a posttranscriptional (before translation) level. Our aim was to review the epigenetic mechanisms that cause heritable changes in gene activity without changing the DNA sequence. We also describe some long-term alterations in the transcriptional potential of a cell, which are not necessarily heritable but remains to be defined in the future. Increasing understanding of the significance of common and rare genetic variants and their relationship to epigenetics and environmental influences may help in establishing methods to assess the risk of AMD. This in turn may allow new therapeutic interventions for the leading cause of central vision impairment in patients over the age of 50 years in developed countries. Search strategy We searched the MEDLINE/PubMed database following MeSH suggestions for articles including the terms: 'ocular epigenetic mechanisms', 'human disease epigenetics', and 'age-related macular degeneration genetics'. The headline used to locate related articles in PubMed was 'epigenetics in ocular disease', and to restrict search, we used the

  8. CREB1/ATF1 Activation in Photoreceptor Degeneration and Protection

    PubMed Central

    Beltran, William A.; Allore, Heather G.; Johnson, Elizabeth; Towle, Virginia; Tao, Weng; Acland, Gregory M.; Aguirre, Gustavo D.

    2009-01-01

    Purpose. The cAMP response element binding protein 1 (CREB1) and activating transcription factor 1 (ATF1) are closely related members of the bZIP superfamily of transcription factors. Both are activated in response to a wide array of stimuli, including cellular stress. This study was conducted to assess the CREB1/ATF1 pathway in photoreceptor disease and protection. Methods. The expression levels of p-CREB1, CREB1, and ATF1 were examined by immunoblot and immunohistochemistry in normal canine retina and retinas of several canine models of retinal degeneration (rcd1, rcd2, erd, prcd, XLPRA1, XLPRA2, T4R RHO). Humans retinas affected with age-related macular degeneration (AMD) were also examined. p-CREB1/ATF1 immunolabeling was assessed in normal and rcd1 dogs treated with ciliary neurotrophic factor (CNTF), to examine the effect of a neuroprotective stimulus on activation of CREB1/ATF1. Results. Native CREB1 and ATF1 as well as phosphorylated CREB1/ATF1 was examined in normal canine retina by immunoblot. The p-CREB1 antibody identified phosphorylated CREB1 and ATF1 and labeled the inner retina only in normal dogs. In degenerate canine and human retinas, strong immunolabeling appeared in rod and cone photoreceptors, indicating increased expression of native CREB1 and ATF1, as well as increased phosphorylation of these proteins. Retinal protection by CNTF in rcd1 dogs was accompanied by a significant increase in the number of p-CREB1/ATF1-labeled photoreceptor nuclei. Conclusions. Positive association of CREB1/ATF1 phosphorylation with photoreceptor protection suggests that it may contribute to an innate protective response. These data identify a signaling mechanism in rods and cones of potential importance for therapies of RP and AMD. PMID:19643965

  9. NEUTRINO PROCESSES IN PARTIALLY DEGENERATE NEUTRON MATTER

    SciTech Connect

    Bacca, S.; Hally, K.; Liebendoerfer, M.; Perego, A.; Pethick, C. J.; Schwenk, A.

    2012-10-10

    We investigate neutrino processes for conditions reached in simulations of core-collapse supernovae. In regions where neutrino-matter interactions play an important role, matter is partially degenerate, and we extend earlier work that addressed the degenerate regime. We derive expressions for the spin structure factor in neutron matter, which is a key quantity required for evaluating rates of neutrino processes. We show that, for essentially all conditions encountered in the post-bounce phase of core-collapse supernovae, it is a very good approximation to calculate the spin relaxation rates in the nondegenerate limit. We calculate spin relaxation rates based on chiral effective field theory interactions and find that they are typically a factor of two smaller than those obtained using the standard one-pion-exchange interaction alone.

  10. Inflammation in intervertebral disc degeneration and regeneration

    PubMed Central

    Molinos, Maria; Almeida, Catarina R.; Caldeira, Joana; Cunha, Carla; Gonçalves, Raquel M.; Barbosa, Mário A.

    2015-01-01

    Intervertebral disc (IVD) degeneration is one of the major causes of low back pain, a problem with a heavy economic burden, which has been increasing in prevalence as populations age. Deeper knowledge of the complex spatial and temporal orchestration of cellular interactions and extracellular matrix remodelling is critical to improve current IVD therapies, which have so far proved unsatisfactory. Inflammation has been correlated with degenerative disc disease but its role in discogenic pain and hernia regression remains controversial. The inflammatory response may be involved in the onset of disease, but it is also crucial in maintaining tissue homeostasis. Furthermore, if properly balanced it may contribute to tissue repair/regeneration as has already been demonstrated in other tissues. In this review, we focus on how inflammation has been associated with IVD degeneration by describing observational and in vitro studies as well as in vivo animal models. Finally, we provide an overview of IVD regenerative therapies that target key inflammatory players. PMID:25673296

  11. Dichromatic Langmuir waves in degenerate quantum plasma

    SciTech Connect

    Dubinov, A. E. Kitayev, I. N.

    2015-06-15

    Langmuir waves in fully degenerate quantum plasma are considered. It is shown that, in the linear approximation, Langmuir waves are always dichromatic. The low-frequency component of the waves corresponds to classical Langmuir waves, while the high-frequency component, to free-electron quantum oscillations. The nonlinear problem on the profile of dichromatic Langmuir waves is solved. Solutions in the form of a superposition of waves and in the form of beatings of its components are obtained.

  12. Anterograde Degeneration along the Visual Pathway after Optic Nerve Injury

    PubMed Central

    Graham, Stuart L.; Klistorner, Alexander

    2012-01-01

    Purpose To investigate anterograde degenerative changes along the visual pathway in a rat model of optic nerve axotomy. Methods Optic nerve transection was performed in adult Sprague-Dawley rats. Animals were sacrificed at regular time intervals and tissues harvested. Immunoblotting followed by densitometric analysis was used to determine the phosphorylation profile of Akt in the dorsal lateral geniculate nucleus (dLGN) and the primary visual cortex (V1). The neuronal cell size and cell density were measured in the dLGN and the V1 using Nissl staining. The prevalence of apoptosis was characterized by terminal deoxynucleotidyl-transferase-mediated biotin-dUTP nick end labelling (TUNEL) histochemistry. Caspase-3 antibodies were also used to identify apoptotic cells. Neurons and astrocytes were detected using NeuN and glial fibrillary acidic protein (GFAP), respectively. Results An early and sustained loss of Akt phosphorylation was observed after optic nerve transection in both dLGN and V1. At week one, a decrease in the neuronal cell size (50.5±4.9 vs 60.3±5.0 µm2, P = 0.042) and an increase of TUNEL positive cells (7.9±0.6 vs 1.4±0.5 ×102 cells/mm2, P<0.001) were evident in the dLGN but not in V1. A significant decline in neuronal cell number (14.5±0.1 vs 17.4±1.3 ×102 cells/mm2, P = 0.048), cell size (42.5±4.3 vs 62.1±4.7 µm2, P = 0.001) and an increase in apoptotic cells (5.6±0.5 vs 2.0±0.4 ×102 cells/mm2, P<0.001) appeared in V1 initially at one month post-transection. The changes in the visual pathway continued through two months. Both neuronal cells and GFAP-positive glial cells were affected in this anterograde degeneration along the visual pathway. Conclusions Anterograde degeneration along the visual pathway takes place in target relay (LGN) and visual cortex following the optic nerve injury. Apoptosis was observed in both neural and adjacent glial cells. Reduction of Akt phosphorylation preceded cellular and apoptotic changes

  13. Patterns of striatal degeneration in frontotemporal dementia

    PubMed Central

    Halabi, Cathra; Halabi, Anasheh; Dean, David L.; Wang, Pei-Ning; Boxer, Adam L.; Trojanowski, John Q.; DeArmond, Stephen J.; Miller, Bruce L.; Kramer, Joel H.; Seeley, William W.

    2012-01-01

    Behavioral variant frontotemporal dementia and semantic dementia have been associated with striatal degeneration, but few studies have delineated striatal subregion volumes in vivo or related them to clinical phenotype. We traced caudate, putamen, and nucleus accumbens on MR images to quantify volumes of these structures in behavioral variant frontotemporal dementia, semantic dementia, Alzheimer’s disease, and healthy controls (n = 12 per group). We further related these striatal volumes to clinical deficits and neuropathological findings in a subset of patients. Behavioral variant frontotemporal dementia and semantic dementia showed significant overall striatal atrophy compared with controls. Moreover, behavioral variant frontotemporal dementia showed panstriatal degeneration whereas semantic dementia featured a more focal pattern involving putamen and accumbens. Right-sided striatal atrophy, especially in the putamen, correlated with overall behavioral symptom severity and with specific behavioral domains. At autopsy, patients with behavioral variant frontotemporal dementia and semantic dementia showed striking and severe tau or TAR DNA-binding protein of 43 kDa pathology, especially in ventral parts of the striatum. These results demonstrate that ventral striatum degeneration is a prominent shared feature in behavioral variant frontotemporal dementia and semantic dementia and may contribute to social-emotional deficits common to both disorders. PMID:22367382

  14. Hypertrophic olivary degeneration secondary to pontine haemorrhage.

    PubMed

    Wein, Sara; Yan, Bernard; Gaillard, Frank

    2015-07-01

    We report a 58-year-old man who developed hyptertrophic olivary degeneration (HOD) after haemorrhage of a cavernous malformation in the pons. Lesions of the triangle of Guillain and Mollaret (the dentatorubro-olivary pathway) may lead to HOD, a secondary transsynaptic degeneration of the inferior olivary nucleus. HOD is considered unique because the degenerating olive initially becomes hypertrophic rather than atrophic. The primary lesion causing pathway interruption is often haemorrhage, either due to hypertension, trauma, surgery or, as in our patient, a vascular malformation such as a cavernoma. Ischaemia and demyelination can also occasionally be the inciting events. The classic clinical presentation of HOD is palatal myoclonus, although not all patients with HOD develop this symptom. The imaging features of HOD evolve through characteristic phases. The clue to the diagnosis of HOD is recognition of the distinct imaging stages and identification of a remote primary lesion in the triangle of Guillain and Mollaret. Familiarity with the classic imaging findings of this rare phenomenon is necessary in order to avoid misdiagnosis and prevent unnecessary intervention.

  15. Kangaroo rats exhibit spongiform degeneration of the central auditory system similar to that found in gerbils.

    PubMed

    McGinn, M D; Faddis, B T

    1997-02-01

    Kangaroo rats develop spongiform degeneration of the central auditory system similar to that seen in the gerbil. Light microscopic and transmission electron microscopic study of the cochlear nucleus and auditory nerve root (ANR) of Dipodomys deserti and D. merriami show that spongiform lesions develop in dendrites and oligodendrocytes of the cochlear nucleus and in oligodendrocytes of the ANR that are morphologically indistinguishable from those extensively described in the Mongolian gerbil, Meriones unguiculatus. As in Mongolian gerbils, the spongiform degeneration in Dipodomys were much more numerous in animals continually exposed to modest levels of low-frequency noise (< 75 dB SPL). The kangaroo rats with extensive spongiform degeneration also show slightly, but significantly, elevated auditory brainstem evoked response (ABR) thresholds to low-frequency stimuli, a result also found in Mongolian gerbils. These results suggest that the elevated ABR thresholds may be the result of spongiform degeneration. Because low-frequency noise-induced spongiform degeneration has now been shown in the cochlear nucleus of animals from separate families of Rodentia (Heteromyidae and Muridae), the possibility should be investigated that similar noise-induced degenerative changes occur in the central auditory system of other mammals with good low-frequency hearing.

  16. Disc in Flames: Roles of TNF-α and IL-1β in Intervertebral Disc Degeneration

    PubMed Central

    Johnson, Zariel I.; Schoepflin, Zachary R.; Choi, Hyowon; Shapiro, Irving M.; Risbud, Makarand V.

    2016-01-01

    The intervertebral disc is an important mechanical structure that allows range of motion of the spinal column. Degeneration of the intervertebral disc, incited by aging, traumatic insult, genetic predisposition, or other factors, is often defined by functional and structural changes in the tissue, including excessive breakdown of the extracellular matrix, increased disc cell senescence and death, and compromised biomechanical function of the tissue. Intervertebral disc degeneration is strongly correlated with low back pain, which is a highly prevalent and costly condition, significantly contributing to loss in productivity and health care costs. Disc degeneration is a chronic, progressive condition, and current therapies are limited and often focused on symptomatic pain relief rather than curtailing the progression of the disease. Inflammatory processes, exacerbated by cytokines TNF-α and IL-1β are believed to be key mediators of disc degeneration and low back pain. In this review, we describe the contributions of TNF-α and IL-1β to changes seen during disc degeneration at the cellular and tissue level, new evidence suggesting a link between infection of the spine and low back pain, and the emerging therapeutic modalities aimed at combating these processes. PMID:26388614

  17. Eicosapentaenoic acid decreases TNF-α and protects dystrophic muscles of mdx mice from degeneration.

    PubMed

    Machado, Rafael Ventura; Mauricio, Adriana Fogagnolo; Taniguti, Ana Paula Tiemi; Ferretti, Renato; Neto, Humberto Santo; Marques, Maria Julia

    2011-03-01

    In dystrophin-deficient fibers of mdx mice and in Duchenne muscular dystrophy, inflammation and increased production of tumor necrosis factor alpha (TNF-α) contribute to myonecrosis. We examined the effects of eicosapentaenoic acid (EPA) on dystrophic muscle degeneration. Mdx mice (14 days old) received EPA for 16 days. The sternomastoid, diaphragm and biceps brachii muscles were removed. Control mdx mice received vehicle. EPA decreased creatine kinase and myonecrosis and reduced the levels of TNF-α. These results suggest that EPA plays a protective role in dystrophic muscle degeneration, possibly by reducing TNF-α, and support further investigations of EPA as a potential therapy for dystrophinopathies.

  18. Mutations in PNPLA6 are linked to photoreceptor degeneration and various forms of childhood blindness

    PubMed Central

    Kmoch, S.; Majewski, J.; Ramamurthy, V.; Cao, S.; Fahiminiya, S.; Ren, H.; MacDonald, I.M.; Lopez, I.; Sun, V.; Keser, V.; Khan, A.; Stránecký, V.; Hartmannová, H.; Přistoupilová, A.; Hodaňová, K.; Piherová, L.; Kuchař, L.; Baxová, A.; Chen, R.; Barsottini, O.G.P.; Pyle, A.; Griffin, H.; Splitt, M.; Sallum, J.; Tolmie, J.L.; Sampson, J.R.; Chinnery, P.; Canada, Care4Rare; Banin, E.; Sharon, D.; Dutta, S.; Grebler, R.; Helfrich-Foerster, C.; Pedroso, J.L.; Kretzschmar, D.; Cayouette, M.; Koenekoop, R.K.

    2015-01-01

    Blindness due to retinal degeneration affects millions of people worldwide, but many disease-causing mutations remain unknown. PNPLA6 encodes the patatin-like phospholipase domain containing protein 6, also known as neuropathy target esterase (NTE), which is the target of toxic organophosphates that induce human paralysis due to severe axonopathy of large neurons. Mutations in PNPLA6 also cause human spastic paraplegia characterized by motor neuron degeneration. Here we identify PNPLA6 mutations in childhood blindness in seven families with retinal degeneration, including Leber congenital amaurosis and Oliver McFarlane syndrome. PNPLA6 localizes mostly at the inner segment plasma membrane in photo-receptors and mutations in Drosophila PNPLA6 lead to photoreceptor cell death. We also report that lysophosphatidylcholine and lysophosphatidic acid levels are elevated in mutant Drosophila. These findings show a role for PNPLA6 in photoreceptor survival and identify phospholipid metabolism as a potential therapeutic target for some forms of blindness. PMID:25574898

  19. The effective density of randomly moving electrons and related characteristics of materials with degenerate electron gas

    SciTech Connect

    Palenskis, V.

    2014-04-15

    Interpretation of the conductivity of metals, of superconductors in the normal state and of semiconductors with highly degenerate electron gas remains a significant issue if consideration is based on the classical statistics. This study is addressed to the characterization of the effective density of randomly moving electrons and to the evaluation of carrier diffusion coefficient, mobility, and other parameters by generalization of the widely published experimental results. The generalized expressions have been derived for various kinetic parameters attributed to the non-degenerate and degenerate electron gas, by analyzing a random motion of the single type carriers in homogeneous materials. The values of the most important kinetic parameters for different metals are also systematized and discussed. It has been proved that Einstein's relation between the diffusion coefficient and the drift mobility of electrons is held for any level of degeneracy if the effective density of randomly moving carriers is properly taken into account.

  20. bcl-2 Overexpression Reduces Apoptotic Photoreceptor Cell Death in Three Different Retinal Degenerations

    NASA Astrophysics Data System (ADS)

    Chen, Jeannie; Flannery, John G.; Lavail, Matthew M.; Steinberg, Roy H.; Xu, Jun; Simon, Melvin I.

    1996-07-01

    Apoptosis of photoreceptors occurs infrequently in adult retina but can be triggered in inherited and environmentally induced retinal degenerations. The protooncogene bcl-2 is known to be a potent regulator of cell survival in neurons. We created lines of transgenic mice overexpressing bcl-2 to test for its ability to increase photoreceptor survival. Bcl-2 increased photoreceptor survival in mice with retinal degeneration caused by a defective opsin or cGMP phosphodiesterase. Overexpression of Bcl-2 in normal photoreceptors also decreased the damaging effects of constant light exposure. Apoptosis was induced in normal photoreceptors by very high levels of bcl-2. We conclude that bcl-2 is an important regulator of photoreceptor cell death in retinal degenerations.

  1. The Oral Iron Chelator Deferiprone Protects against Iron Overload–Induced Retinal Degeneration

    PubMed Central

    Hadziahmetovic, Majda; Song, Ying; Wolkow, Natalie; Iacovelli, Jared; Grieco, Steven; Lee, Jennifer; Lyubarsky, Arkady; Pratico, Domenico; Connelly, John; Spino, Michael; Harris, Z. Leah

    2011-01-01

    Purpose. Iron-induced oxidative stress may exacerbate age-related macular degeneration (AMD). Ceruloplasmin/Hephaestin double-knockout (DKO) mice with age-dependent retinal iron accumulation and some features of AMD were used to test retinal protection by the oral iron chelator deferiprone (DFP). Methods. Cultured retinal pigment epithelial (ARPE-19) cells and mice were treated with DFP. Transferrin receptor mRNA (Tfrc), an indicator of iron levels, was quantified by qPCR. In mice, retinal oxidative stress was assessed by mass spectrometry, and degeneration by histology and electroretinography. Results. DFP at 60 μM decreased labile iron in ARPE-19 cells, increasing Tfrc and protecting 70% of cells against a lethal dose of H2O2. DFP 1 mg/mL in drinking water increased retinal Tfrc mRNA 2.7-fold after 11 days and also increased transferrin receptor protein. In DKOs, DFP over 8 months decreased retinal iron levels to 72% of untreated mice, diminished retinal oxidative stress to 70% of the untreated level, and markedly ameliorated retinal degeneration. DFP was not retina toxic in wild-type (WT) or DKO mice, as assessed by histology and electroretinography. Conclusions. Oral DFP was not toxic to the mouse retina. It diminished retinal iron levels and oxidative stress and protected DKO mice against iron overload–induced retinal degeneration. Further testing of DFP for retinal disease involving oxidative stress is warranted. PMID:21051716

  2. Rare earth nanoparticles prevent retinal degeneration induced by intracellular peroxides:

    NASA Astrophysics Data System (ADS)

    Chen, Junping; Patil, Swanand; Seal, Sudipta; McGinnis, James F.

    2006-11-01

    Photoreceptor cells are incessantly bombarded with photons of light, which, along with the cells' high rate of oxygen metabolism, continuously exposes them to elevated levels of toxic reactive oxygen intermediates (ROIs). Vacancy-engineered mixed-valence-state cerium oxide nanoparticles (nanoceria particles) scavenge ROIs. Our data show that nanoceria particles prevent increases in the intracellular concentrations of ROIs in primary cell cultures of rat retina and, in vivo, prevent loss of vision due to light-induced degeneration of photoreceptor cells. These data indicate that the nanoceria particles may be effective in inhibiting the progression of ROI-induced cell death, which is thought to be involved in macular degeneration, retinitis pigmentosa and other blinding diseases, as well as the ROI-induced death of other cell types in diabetes, Alzheimer's disease, atherosclerosis, stroke and so on. The use of nanoceria particles as a direct therapy for multiple diseases represents a novel strategy and suggests that they may represent a unique platform technology.

  3. Varied interactions between proviruses and adjacent host chromatin.

    PubMed Central

    Conklin, K F; Groudine, M

    1986-01-01

    Retroviruses integrated at unique locations in the host genome can be expressed at different levels. We have analyzed the preintegration sites of three transcriptionally competent avian endogenous proviruses (evs) to determine whether the various levels of provirus expression correlate with their location in active or inactive regions of chromatin. Our results show that in three of four cell types, the chromatin conformation (as defined by relative nuclease sensitivity) of virus preintegration sites correlates with the level of expression of the resident provirus in ev+ cells: two inactive proviruses (ev-1 and ev-2) reside in nuclease-resistant chromatin domains and one active provirus (ev-3) resides in a nuclease-sensitive domain. Nuclear runoff transcription assays reveal that the preintegration sites of the active and inactive viruses are not transcribed. However, in erythrocytes of 15-day-old chicken embryos (15d RBCs), the structure and activity of the ev-3 provirus is independent of the conformation of its preintegration site. In this cell type, the ev-3 preintegration site is organized in a nuclease-resistant conformation, while the ev-3 provirus is in a nuclease-sensitive conformation and is transcribed. In addition, the nuclease sensitivity of host sequences adjacent to ev-3 is altered in ev-3+ 15d RBCs relative to that found in 15d RBCs that lack ev-3. These data suggest that the relationship between preintegration site structure and retrovirus expression is more complex than previously described. Images PMID:3025623

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

    ERIC Educational Resources Information Center

    Koo, Hahn; Callahan, Lydia

    2012-01-01

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

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

    ERIC Educational Resources Information Center

    Gervain, Judit; Werker, Janet F.

    2013-01-01

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

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

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

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

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

    ERIC Educational Resources Information Center

    Greif, Ivo P.

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

  8. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

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

  9. 47 CFR 90.221 - Adjacent channel power limits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

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

  10. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  11. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

  12. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

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

  13. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

  14. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  15. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

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

  16. 30 CFR 56.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  18. 30 CFR 57.14109 - Unguarded conveyors with adjacent travelways.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

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

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

    Code of Federal Regulations, 2012 CFR

    2012-07-01

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

  20. Survivin is expressed in degenerated nucleus pulposus cells and is involved in proliferation and the prevention of apoptosis in vitro

    PubMed Central

    LIN, YAZHOU; YUE, BIN; XIANG, HONGFEI; LIU, YONG; MA, XUEXIAO; CHEN, BOHUA

    2016-01-01

    Survivin is a unique inhibitor of apoptosis, which is frequently present within degenerated human nucleus pulposus (NP) cells. Survivin has been extensively investigated using proliferation and apoptosis assays in tumor cells; however, studies conducted on survivin in degenerative NP cells remain limited to date. The aim of the present study was to investigate survivin expression and its effects on the proliferation and apoptosis of degenerated NP cells in vitro. The expression levels of survivin in the NP cells of patients (>45 years) with lumbar disc degenerative disease and the NP cells of patients (<25 years) with lumbar vertebra fracture were assessed by reverse transcription-quantitative polymerase chain reaction. The effects on in vitro proliferation and apoptosis were investigated through transfection with a specific small interfering (si)RNA. The results of the present study demonstrated that survivin was expressed in the degenerated NP cells, but was undetectable in normal NP cells at the mRNA level. Survivin suppression following transfection with a specific survivin-siRNA reduced the proliferation rate of NP cells and enhanced sensitization to pro-apoptotic stimuli. Therefore, survivin was shown to be expressed and exhibit an important role in the proliferation and prevention of apoptosis of degenerated NP cells. Studies on survivin in NP cells may aid in increasing the understanding of the complex processes underlying NP cell degeneration, and could provide fundamental information for gene therapy to inhibit this degeneration in vitro. PMID:26648308

  1. Depression in Age-Related Macular Degeneration.

    PubMed

    Casten, Robin; Rovner, Barry

    2008-01-01

    Age-related macular degeneration (AMD) is a major cause of disability in the elderly, substantially degrades the quality of their lives, and is a risk factor for depression. Rates of depression in AMD are substantially greater than those found in the general population of older people, and are on par with those of other chronic and disabling diseases. This article discusses the effect of depression on vision-related disability in patients with AMD, suggests methods for screening for depression, and summarizes interventions for preventing depression in this high-risk group.

  2. [Age-related macular degeneration (AMD)].

    PubMed

    Michels, Stephan; Kurz-Levin, Malaika

    2009-03-01

    Today age-related macular degeneration (AMD) is the most frequent cause for legal blindness in western industrialized countries. The prevalence of this disease rises with increasing age. A multifactorial pathogenesis of AMD is postulated including genetic predisposition and environmental risk factors. The most relevant modifiable risk factor is smoking. Up to today there is no cure of this chronic disease. Prophylaxis, including a healthy diet and antioxidants as nutrional supplements for selected patients, aims to slow down the disease progression. Significant progress has been made in the treatment of the neovascular form of the disease using inhibitors of the vascular endothelial growth factor (VEGF).

  3. Target Positioning and Tracking in Degenerate Geometry

    DTIC Science & Technology

    2011-07-01

    estimation accuracy is to use the geometric dilution of precision ( GDOP ) [8]. In a poor geometry with not enough independent measurements and/or nearly...in GDOP may be significant, leading to degenerate cases. Indeed, when a target is close to or crosses the baseline, the 2D solution is no longer...7) is given by (8). The resulting position error is σx = √2/2σ, which is equivalent to having a GDOP of 0.707, the lowest of the 2D solution. A

  4. Can subretinal microphotodiodes successfully replace degenerated photoreceptors?

    PubMed

    Zrenner, E; Stett, A; Weiss, S; Aramant, R B; Guenther, E; Kohler, K; Miliczek, K D; Seiler, M J; Haemmerle, H

    1999-07-01

    The idea of implanting microphotodiode arrays as visual prostheses has aroused controversy on its feasibility from the moment it appeared in print. We now present results which basically support the concept of replacing damaged photoreceptors with subretinally implanted stimulation devices. Network activity in degenerated rat retinae could be modulated through local electrical stimulation in vitro. We also investigated the long term stability and biocompatibility of the subretinal implants and their impact on retinal physiology in rats. Ganzfeld electroretinograms and histology showed no significant side effect of subretinal implants on retinal function or the architecture of the inner retina.

  5. Mechanisms of secondary degeneration after partial optic nerve transection

    PubMed Central

    Li, Hong-Ying; Ruan, Yi-Wen; Ren, Chao-Ran; Cui, Qi; So, Kwok-Fai

    2014-01-01

    Secondary degeneration occurs commonly in the central nervous system after traumatic injuries and following acute and chronic diseases, including glaucoma. A constellation of mechanisms have been shown to be associated with secondary degeneration including apoptosis, necrosis, autophagy, oxidative stress, excitotoxicity, derangements in ionic homeostasis and calcium influx. Glial cells, such as microglia, astrocytes and oligodendrocytes, have also been demonstrated to take part in the process of secondary injury. Partial optic nerve transection is a useful model which was established about 13 years ago. The merit of this model compared with other optic nerve injury models used for glaucoma study, including complete optic nerve transection model and optic nerve crush model, is the possibility to separate primary degeneration from secondary degeneration in location. Therefore, it provides a good tool for the study of secondary degeneration. This review will focus on the research progress of the mechanisms of secondary degeneration using partial optic nerve transection model. PMID:25206855

  6. Hydrologic Connection Between Geysers and Adjacent Thermal Pools, Two Examples: El Tatio, Chile and Yellowstone, USA

    NASA Astrophysics Data System (ADS)

    Munoz Saez, C.; Fauria, K.; Manga, M.; Hurwitz, S.; Namiki, A.

    2014-12-01

    Geyser eruption cycles can be influenced by adjacent and distant thermals sources, suggesting a hydraulic connection through permeable pathways. Diffusion of fluid pressure can be responsible for the communication between geysers. In this study we examine the processes linking two different geysers with adjacent thermal pools. The first was Vega Rinconada, located at El Tatio geyser field, Chile, where we measured temperature inside the conduit between the ground surface and a depth of seven meters, at one-meter intervals. The second was Lone Star Geyser in Yellowstone National Park, where we measured temperature of the overflow water at the base of the cone. Concurrently, we measured temperature and the water level in pools adjacent to both geysers. We found common elements in both geyser - pool systems: First, water temperature in both adjacent pools was below the boiling point and cooler than water in the geysers. Second, changes in pool water levels were correlated with eruptions of the geysers. During the quiescent period of the geysers, the water level increased in adjacent pools, while water level in the pools deceased during eruptions. Additionally, measurements inside of the conduit in Vega Rinconada Geyser showed that water temperature increased in the deepest part of the conduit during eruptions, while water temperature decreased in the shallow part of the geyser conduit (~1 to 2 m). These drops in temperature in the shallow conduit were coincident with the drop in water level in the adjacent pool. This suggests that after the initiation of an eruption, water may drain from the pool to the geyser. Furthermore, we observed a temperature drop of 3oC in the shallow conduit immediately preceding the end of an eruption. This suggests that flow from the pool to geyser contributes to eruption shut off. Our observations of geyser-pool systems indicate a hydrologic connection between the geysers and their adjacent pools. In the case of Vega Rinconada, cold water

  7. A novel noise optimization technique for inductively degenerated CMOS LNA

    NASA Astrophysics Data System (ADS)

    Zhiqing, Geng; Haiyong, Wang; Nanjian, Wu

    2009-10-01

    This paper proposes a novel noise optimization technique. The technique gives analytical formulae for the noise performance of inductively degenerated CMOS low noise amplifier (LNA) circuits with an ideal gate inductor for a fixed bias voltage and nonideal gate inductor for a fixed power dissipation, respectively, by mathematical analysis and reasonable approximation methods. LNA circuits with required noise figure can be designed effectively and rapidly just by using hand calculations of the proposed formulae. We design a 1.8 GHz LNA in a TSMC 0.25 μm CMOS process. The measured results show a noise figure of 1.6 dB with a forward gain of 14.4 dB at a power consumption of 5 mW, demonstrating that the designed LNA circuits can achieve low noise figure levels at low power dissipation.

  8. TIME-SERIES SPECTROSCOPY OF TWO CANDIDATE DOUBLE DEGENERATES IN THE OPEN CLUSTER NGC 6633

    SciTech Connect

    Williams, Kurtis A.; Chakraborty, Subho; Serna-Grey, Donald; Gianninas, A.; Canton, Paul A.

    2015-12-15

    SNe Ia are heavily used tools in precision cosmology, yet we still are not certain what the progenitor systems are. General plausibility arguments suggest there is potential for identifying double degenerate SN Ia progenitors in intermediate-age open star clusters. We present time-resolved high-resolution spectroscopy of two white dwarfs (WDs) in the field of the open cluster NGC 6633 that had previously been identified as candidate double degenerates in the cluster. However, three hours of continuous observations of each candidate failed to detect any significant radial velocity variations at the ≳10 km s{sup −1} level, making it highly unlikely that either WD is a double degenerate that will merge within a Hubble Time. The WD LAWDS NGC 6633 4 has a radial velocity inconsistent with cluster membership at the 2.5σ level, while the radial velocity of LAWDS NGC 6633 7 is consistent with cluster membership. We conservatively conclude that LAWDS 7 is a viable massive double degenerate candidate, though unlikely to be a Type Ia progenitor. Astrometric data from GAIA will likely be needed to determine if either WD is truly a cluster member.

  9. PGC-1α regulation of mitochondrial degeneration in experimental diabetic neuropathy.

    PubMed

    Choi, Joungil; Chandrasekaran, Krish; Inoue, Tatsuya; Muragundla, Anjaneyulu; Russell, James W

    2014-04-01

    Mitochondrial degeneration is considered to play an important role in the development of diabetic peripheral neuropathy in humans. Mitochondrial degeneration and the corresponding protein regulation associated with the degeneration were studied in an animal model of diabetic neuropathy. PGC-1α and its-regulated transcription factors including TFAM and NRF1, which are master regulators of mitochondrial biogenesis, are significantly downregulated in streptozotocin diabetic dorsal root ganglion (DRG) neurons. Diabetic mice develop peripheral neuropathy, loss of mitochondria, decreased mitochondrial DNA content and increased protein oxidation. Importantly, this phenotype is exacerbated in PGC-1α (-/-) diabetic mice, which develop a more severe neuropathy with reduced mitochondrial DNA and a further increase in protein oxidation. PGC-1α (-/-) diabetic mice develop an increase in total cholesterol and triglycerides, and a decrease in TFAM and NRF1 protein levels. Loss of PGC-1α causes severe mitochondrial degeneration with vacuolization in DRG neurons, coupled with reduced state 3 and 4 respiration, reduced expression of oxidative stress response genes and an increase in protein oxidation. In contrast, overexpression of PGC-1α in cultured adult mouse neurons prevents oxidative stress associated with increased glucose levels. The study provides new insights into the role of PGC-1α in mitochondrial regeneration in peripheral neurons and suggests that therapeutic modulation of PGC-1α function may be an attractive approach for treatment of diabetic neuropathy.

  10. Wallerian degeneration in ICAM-1-deficient mice.

    PubMed Central

    Vougioukas, V. I.; Roeske, S.; Michel, U.; Brück, W.

    1998-01-01

    Wallerian degeneration of the peripheral nervous system was studied in ICAM-1-deficient mice and compared with the phenomena observed in C57BL wild-type animals. There was a decrease in myelin density in both mice strains 4 and 6 days after transection of the sciatic nerve. The degenerating nerves were invaded by Mac-1-, LFA-1-, and F4/80-positive macrophages; significantly lower numbers of macrophages were present in ICAM-1-deficient nerves. Myelin loss decreased after nerve transection with a more prominent loss in ICAM-1-deficient animals. Schwann cells revealed a much higher myelin load in these animals when compared with wild-type nerves, and there was an increased proliferation of endoneurial cells in ICAM-1-deficient mice. These data indicate that ICAM-1 is involved in macrophage recruitment to injured peripheral nerves as well as in the proliferative and phagocytic response of Schwann cells after peripheral nerve transection. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:9422541

  11. Metabolic anatomy of paraneoplastic cerebellar degeneration

    SciTech Connect

    Anderson, N.E.; Posner, J.B.; Sidtis, J.J.; Moeller, J.R.; Strother, S.C.; Dhawan, V.; Rottenberg, D.A.

    1988-06-01

    Eleven patients with acquired cerebellar degeneration (10 of whom had paraneoplastic cerebellar degeneration (PCD)) were evaluated using neuropsychological tests and /sup 18/F-fluorodeoxyglucose/positron emission tomography to (1) quantify motor, cognitive, and metabolic abnormalities; (2) determine if characteristic alterations in the regional cerebral metabolic rate for glucose (rCMRGlc) are associated with PCD; and (3) correlate behavioral and metabolic measures of disease severity. Eighteen volunteer subjects served as normal controls. Although some PCD neuropsychological test scores were abnormal, these results could not, in general, be dissociated from the effects of dysarthria and ataxia. rCMRGlc was reduced in patients with PCD (versus normal control subjects) in all regions except the brainstem. Analysis of patient and control rCMRGlc data using a mathematical model of regional metabolic interactions revealed two metabolic pattern descriptors, SSF1 and SSF2, which distinguished patients with PCD from normal control subjects; SSF2, which described a metabolic coupling between cerebellum, cuneus, and posterior temporal, lateral frontal, and paracentral cortex, correlated with quantitative indices of cerebellar dysfunction. Our inability to document substantial intellectual impairment in 7 of 10 patients with PCD contrasts with the 50% incidence of dementia in PCD reported by previous investigators. Widespread reductions in PCD rCMRGlc may result from the loss of cerebellar efferents to thalamus and forebrain structures, a reverse cerebellar diaschisis.

  12. Degenerate parametric oscillation in quantum membrane optomechanics

    NASA Astrophysics Data System (ADS)

    Benito, Mónica; Sánchez Muñoz, Carlos; Navarrete-Benlloch, Carlos

    2016-02-01

    The promise of innovative applications has triggered the development of many modern technologies capable of exploiting quantum effects. But in addition to future applications, such quantum technologies have already provided us with the possibility of accessing quantum-mechanical scenarios that seemed unreachable just a few decades ago. With this spirit, in this work we show that modern optomechanical setups are mature enough to implement one of the most elusive models in the field of open system dynamics: degenerate parametric oscillation. Introduced in the eighties and motivated by its alleged implementability in nonlinear optical resonators, it rapidly became a paradigm for the study of dissipative phase transitions whose corresponding spontaneously broken symmetry is discrete. However, it was found that the intrinsic multimode nature of optical cavities makes it impossible to experimentally study the model all the way through its phase transition. In contrast, here we show that this long-awaited model can be implemented in the motion of a mechanical object dispersively coupled to the light contained in a cavity, when the latter is properly driven with multichromatic laser light. We focus on membranes as the mechanical element, showing that the main signatures of the degenerate parametric oscillation model can be studied in state-of-the-art setups, thus opening the possibility of analyzing spontaneous symmetry breaking and enhanced metrology in one of the cleanest dissipative phase transitions. In addition, the ideas put forward in this work would allow for the dissipative preparation of squeezed mechanical states.

  13. Progressive retinal degeneration in ranch mink.

    PubMed

    Hadlow, W J

    1984-01-01

    Retinal degeneration was prevalent in a large group of sapphire and pastel mink (Mustela vison) kept for studies on slow viral diseases. Nearly 78% of those two to eight years old were affected. The retinopathy was equally common in both sexes but more frequent in sapphires (85%) than in pastels (63%), and it was severe more often in sapphires than in pastels. By light microscopy, the primary change appeared to be progressive degeneration of fully developed photoreceptors, beginning in their outer segments. In many mink, including some younger ones, the rods and cones and outer nuclear layer had disappeared from all but the far periphery of the fundus. The inner retinal layers were spared until late in the disease, and the pigment epithelium remained essentially unchanged. The cause of the retinopathy was not established. It may represent an abiotrophy in which the structural integrity of the photoreceptors began to wane in many mink after they reached two years of age. Apart from reducing visual acuity, the retinopathy has implications for the photoperiodic control of fur growth and reproduction in this highly light-sensitive carnivore.

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

    NASA Astrophysics Data System (ADS)

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

    1990-04-01

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

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

    SciTech Connect

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

    2013-01-14

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

  16. Activity loss and depression in age-related macular degeneration.

    PubMed

    Rovner, Barry W; Casten, Robin J

    2002-01-01

    Age-related macular degeneration (AMD) is the most frequent cause of severe vision loss in older persons and is associated with high rates of disability and depression. The authors evaluated 51 patients with bilateral AMD to investigate the interrelationships of disease severity, disability, and depression and focused on loss of valued activities as an emblematic disabling consequence of AMD. They characterized depression by the Center for Epidemiologic Studies-Depression (CES-D) score, a syndromal state based on the CES-D, and as a level of distress (Index of Affective Suffering; IAS). Thirty subjects (58.8%) had loss of a valued, discretionary activity. They had worse visual acuity and more depressive symptoms and were represented in higher IAS levels than other subjects. Visual acuity was significantly correlated with IAS levels, but not with CES-D scores or syndromal depression. A regression model demonstrated that activity loss mediated the relationship between visual acuity and IAS level. Affective distress occurs in AMD, largely to the extent that valued activities are relinquished because of vision loss. IAS levels best illuminated this relationship, suggesting the value of this dimension of affective functioning in studies of the consequences of chronic disease.

  17. Purkinje Cell Degeneration in pcd Mice Reveals Large Scale Chromatin Reorganization and Gene Silencing Linked to Defective DNA Repair*

    PubMed Central

    Baltanás, Fernando C.; Casafont, Iñigo; Lafarga, Vanesa; Weruaga, Eduardo; Alonso, José R.; Berciano, María T.; Lafarga, Miguel

    2011-01-01

    DNA repair protects neurons against spontaneous or disease-associated DNA damage. Dysfunctions of this mechanism underlie a growing list of neurodegenerative disorders. The Purkinje cell (PC) degeneration mutation causes the loss of nna1 expression and is associated with the postnatal degeneration of PCs. This PC degeneration dramatically affects nuclear architecture and provides an excellent model to elucidate the nuclear mechanisms involved in a whole array of neurodegenerative disorders. We used immunocytochemistry for histone variants and components of the DNA damage response, an in situ transcription assay, and in situ hybridization for telomeres to analyze changes in chromatin architecture and function. We demonstrate that the phosphorylation of H2AX, a DNA damage signal, and the trimethylation of the histone H4K20, a repressive mark, in extensive domains of genome are epigenetic hallmarks of chromatin in degenerating PCs. These histone modifications are associated with a large scale reorganization of chromatin, telomere clustering, and heterochromatin-induced gene silencing, all of them key factors in PC degeneration. Furthermore, ataxia telangiectasia mutated and 53BP1, two components of the DNA repair pathway, fail to be concentrated in the damaged chromatin compartments, even though the expression levels of their coding genes were slightly up-regulated. Although the mechanism by which Nna1 loss of function leads to PC neurodegeneration is undefined, the progressive accumulation of DNA damage in chromosome territories irreversibly compromises global gene transcription and seems to trigger PC degeneration and death. PMID:21700704

  18. A Novel Method to Simulate the Progression of Collagen Degeneration of Cartilage in the Knee: Data from the Osteoarthritis Initiative

    NASA Astrophysics Data System (ADS)

    Mononen, Mika E.; Tanska, Petri; Isaksson, Hanna; Korhonen, Rami K.

    2016-02-01

    We present a novel algorithm combined with computational modeling to simulate the development of knee osteoarthritis. The degeneration algorithm was based on excessive and cumulatively accumulated stresses within knee joint cartilage during physiological gait loading. In the algorithm, the collagen network stiffness of cartilage was reduced iteratively if excessive maximum principal stresses were observed. The developed algorithm was tested and validated against experimental baseline and 4-year follow-up Kellgren-Lawrence grades, indicating different levels of cartilage degeneration at the tibiofemoral contact region. Test groups consisted of normal weight and obese subjects with the same gender and similar age and height without osteoarthritic changes. The algorithm accurately simulated cartilage degeneration as compared to the Kellgren-Lawrence findings in the subject group with excess weight, while the healthy subject group’s joint remained intact. Furthermore, the developed algorithm followed the experimentally found trend of cartilage degeneration in the obese group (R2 = 0.95, p < 0.05 experiments vs. model), in which the rapid degeneration immediately after initiation of osteoarthritis (0–2 years, p < 0.001) was followed by a slow or negligible degeneration (2–4 years, p > 0.05). The proposed algorithm revealed a great potential to objectively simulate the progression of knee osteoarthritis.

  19. A Novel Method to Simulate the Progression of Collagen Degeneration of Cartilage in the Knee: Data from the Osteoarthritis Initiative

    PubMed Central

    Mononen, Mika E.; Tanska, Petri; Isaksson, Hanna; Korhonen, Rami K.

    2016-01-01

    We present a novel algorithm combined with computational modeling to simulate the development of knee osteoarthritis. The degeneration algorithm was based on excessive and cumulatively accumulated stresses within knee joint cartilage during physiological gait loading. In the algorithm, the collagen network stiffness of cartilage was reduced iteratively if excessive maximum principal stresses were observed. The developed algorithm was tested and validated against experimental baseline and 4-year follow-up Kellgren-Lawrence grades, indicating different levels of cartilage degeneration at the tibiofemoral contact region. Test groups consisted of normal weight and obese subjects with the same gender and similar age and height without osteoarthritic changes. The algorithm accurately simulated cartilage degeneration as compared to the Kellgren-Lawrence findings in the subject group with excess weight, while the healthy subject group’s joint remained intact. Furthermore, the developed algorithm followed the experimentally found trend of cartilage degeneration in the obese group (R2 = 0.95, p < 0.05; experiments vs. model), in which the rapid degeneration immediately after initiation of osteoarthritis (0–2 years, p < 0.001) was followed by a slow or negligible degeneration (2–4 years, p > 0.05). The proposed algorithm revealed a great potential to objectively simulate the progression of knee osteoarthritis. PMID:26906749

  20. Gene promoter methylation in colorectal cancer and healthy adjacent mucosa specimens

    PubMed Central

    Coppedè, Fabio; Migheli, Francesca; Lopomo, Angela; Failli, Alessandra; Legitimo, Annalisa; Consolini, Rita; Fontanini, Gabriella; Sensi, Elisa; Servadio, Adele; Seccia, Massimo; Zocco, Giuseppe; Chiarugi, Massimo; Spisni, Roberto; Migliore, Lucia

    2014-01-01

    We evaluated the promoter methylation levels of the APC, MGMT, hMLH1, RASSF1A and CDKN2A genes in 107 colorectal cancer (CRC) samples and 80 healthy adjacent tissues. We searched for correlation with both physical and pathological features, polymorphisms of folate metabolism pathway genes (MTHFR, MTRR, MTR, RFC1, TYMS, and DNMT3B), and data on circulating folate, vitamin B12 and homocysteine, which were available in a subgroup of the CRC patients. An increased number of methylated samples were found in CRC respect to adjacent healthy tissues, with the exception of APC, which was also frequently methylated in healthy colonic mucosa. Statistically significant associations were found between RASSF1A promoter methylation and tumor stage, and between hMLH1 promoter methylation and tumor location. Increasing age positively correlated with both hMLH1 and MGMT methylation levels in CRC tissues, and with APC methylation levels in the adjacent healthy mucosa. Concerning gender, females showed higher hMLH1 promoter methylation levels with respect to males. In CRC samples, the MTR 2756AG genotype correlated with higher methylation levels of RASSF1A, and the TYMS 1494 6bp ins/del polymorphism correlated with the methylation levels of both APC and hMLH1. In adjacent healthy tissues, MTR 2756AG and TYMS 1494 6bp del/del genotypes correlated with APC and MGMT promoter methylation, respectively. Low folate levels were associated with hMLH1 hypermethylation. Present results support the hypothesis that DNA methylation in CRC depends from both physiological and environmental factors, with one-carbon metabolism largely involved in this process. PMID:24500500

  1. The role of epigenetics in age-related macular degeneration

    PubMed Central

    Gemenetzi, M; Lotery, A J

    2014-01-01

    It is becoming increasingly evident that epigenetic mechanisms influence gene expression and can explain how interactions between genetics and the environment result in particular phenotypes during development. The extent to which this epigenetic effect contributes to phenotype heritability in age-related macular degeneration (AMD) is currently ill defined. However, emerging evidence suggests that epigenetic changes are relevant to AMD and as such provide an exciting new avenue of research for AMD. This review addresses information on the impact of posttranslational modification of the genome on the pathogenesis of AMD, such as DNA methylation changes affecting antioxidant gene expression, hypoxia-regulated alterations in chromatin structure, and histone acetylation status in relation to angiogenesis and inflammation. It also contains information on the role of non-coding RNA-mediated gene regulation in AMD at a posttranscriptional (before translation) level. Our aim was to review the epigenetic mechanisms that cause heritable changes in gene activity without changing the DNA sequence. We also describe some long-term alterations in the transcriptional potential of a cell, which are not necessarily heritable but remains to be defined in the future. Increasing understanding of the significance of common and rare genetic variants and their relationship to epigenetics and environmental influences may help in establishing methods to assess the risk of AMD. This in turn may allow new therapeutic interventions for the leading cause of central vision impairment in patients over the age of 50 years in developed countries. Search strategy We searched the MEDLINE/PubMed database following MeSH suggestions for articles including the terms: ‘ocular epigenetic mechanisms', ‘human disease epigenetics', and ‘age-related macular degeneration genetics'. The headline used to locate related articles in PubMed was ‘epigenetics in ocular disease', and to restrict search, we used

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    PubMed

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

    2016-06-01

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

    PubMed

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

    2003-06-01

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

  10. Microbial Source Tracking in Adjacent Karst Springs.

    PubMed

    Ohad, Shoshanit; Vaizel-Ohayon, Dalit; Rom, Meir; Guttman, Joseph; Berger, Diego; Kravitz, Valeria; Pilo, Shlomo; Huberman, Zohar; Kashi, Yechezkel; Rorman, Efrat

    2015-08-01

    Modern man-made environments, including urban, agricultural, and industrial environments, have complex ecological interactions among themselves and with the natural surroundings. Microbial source tracking (MST) offers advanced tools to resolve the host source of fecal contamination beyond indicator monitoring. This study was intended to assess karst spring susceptibilities to different fecal sources using MST quantitative PCR (qPCR) assays targeting human, bovine, and swine markers. It involved a dual-time monitoring frame: (i) monthly throughout the calendar year and (ii) daily during a rainfall event. Data integration was taken from both monthly and daily MST profile monitoring and improved identification of spring susceptibility to host fecal contamination; three springs located in close geographic proximity revealed different MST profiles. The Giach spring showed moderate fluctuations of MST marker quantities amid wet and dry samplings, while the Zuf spring had the highest rise of the GenBac3 marker during the wet event, which was mirrored in other markers as well. The revelation of human fecal contamination during the dry season not connected to incidents of raining leachates suggests a continuous and direct exposure to septic systems. Pigpens were identified in the watersheds of Zuf, Shefa, and Giach springs and on the border of the Gaaton spring watershed. Their impact was correlated with partial detection of the Pig-2-Bac marker in Gaaton spring, which was lower than detection levels in all three of the other springs. Ruminant and swine markers were detected intermittently, and their contamination potential during the wet samplings was exposed. These results emphasized the importance of sampling design to utilize the MST approach to delineate subtleties of fecal contamination in the environment.

  11. Capsaicin Induces Degeneration of Cutaneous Autonomic Nerve Fibers

    PubMed Central

    Gibbons, Christopher H; Wang, Ningshan; Freeman, Roy

    2010-01-01

    Objective To determine the effects of topical application of capsaicin on cutaneous autonomic nerves. Methods Thirty-two healthy subjects underwent occlusive application of 0.1% capsaicin cream (or placebo) for 48 hours. Subjects were followed for 6 months with serial assessments of sudomotor, vasomotor, pilomotor and sensory function with simultaneous assessment of innervation through skin biopsies. Results There were reductions in sudomotor, vasomotor, pilomotor and sensory function in capsaicin- treated subjects (p<0.01 vs. placebo). Sensory function declined more rapidly than autonomic function; reaching a nadir by day 6 while autonomic function reached a nadir by day 16. There were reductions in sudomotor, vasomotor, pilomotor and sensory nerve fiber densities in capsaicin treated subjects (p<0.01 vs. placebo). Intra-epidermal nerve fiber density declined maximally by 6 days while autonomic nerve fiber densities reached maximal degeneration by day 16. Conversely, autonomic nerves generally regenerated more rapidly than sensory nerves, requiring 40–50 days to return to baseline levels while sensory fibers required 140–150 days to return to baseline. Interpretation Topical capsaicin leads to degeneration of sudomotor, vasomotor and pilomotor nerves accompanied by impairment of sudomotor, vasomotor and pilomotor function. These results suggest the susceptibility and/or pathophysiologic mechanisms of nerve damage may differ between autonomic and sensory nerve fibers treated with capsaicin and enhances the capsaicin model for the study of disease modifying agents. The data suggest caution should be taken when topical capsaicin is applied to skin surfaces at risk for ulceration, particularly in neuropathic conditions characterized by sensory and autonomic impairment. PMID:21061393

  12. Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy.

    PubMed

    Lee, Yun-Sil; Lehar, Adam; Sebald, Suzanne; Liu, Min; Swaggart, Kayleigh A; Talbot, C Conover; Pytel, Peter; Barton, Elisabeth R; McNally, Elizabeth M; Lee, Se-Jin

    2015-10-15

    Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf(-/-)) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf(-/-) mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf(-/-) mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf(-/-) mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf(-/-) mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis.

  13. Muscle hypertrophy induced by myostatin inhibition accelerates degeneration in dysferlinopathy

    PubMed Central

    Lee, Yun-Sil; Lehar, Adam; Sebald, Suzanne; Liu, Min; Swaggart, Kayleigh A.; Talbot, C. Conover; Pytel, Peter; Barton, Elisabeth R.; McNally, Elizabeth M.; Lee, Se-Jin

    2015-01-01

    Myostatin is a secreted signaling molecule that normally acts to limit muscle growth. As a result, there is extensive effort directed at developing drugs capable of targeting myostatin to treat patients with muscle loss. One potential concern with this therapeutic approach in patients with muscle degenerative diseases like muscular dystrophy is that inducing hypertrophy may increase stress on dystrophic fibers, thereby accelerating disease progression. To investigate this possibility, we examined the effect of blocking the myostatin pathway in dysferlin-deficient (Dysf−/−) mice, in which membrane repair is compromised, either by transgenic expression of follistatin in skeletal muscle or by systemic administration of the soluble form of the activin type IIB receptor (ACVR2B/Fc). Here, we show that myostatin inhibition by follistatin transgene expression in Dysf−/− mice results in early improvement in histopathology but ultimately exacerbates muscle degeneration; this effect was not observed in dystrophin-deficient (mdx) mice, suggesting that accelerated degeneration induced by follistatin transgene expression is specific to mice lacking dysferlin. Dysf−/− mice injected with ACVR2B/Fc showed significant increases in muscle mass and amelioration of fibrotic changes normally seen in 8-month-old Dysf−/− mice. Despite these potentially beneficial effects, ACVR2B/Fc treatment caused increases in serum CK levels in some Dysf−/− mice, indicating possible muscle damage induced by hypertrophy. These findings suggest that depending on the disease context, inducing muscle hypertrophy by myostatin blockade may have detrimental effects, which need to be weighed against the potential gains in muscle growth and decreased fibrosis. PMID:26206886

  14. Inflammation and its role in age-related macular degeneration.

    PubMed

    Kauppinen, Anu; Paterno, Jussi J; Blasiak, Janusz; Salminen, Antero; Kaarniranta, Kai

    2016-05-01

    Inflammation is a cellular response to factors that challenge the homeostasis of cells and tissues. Cell-associated and soluble pattern-recognition receptors, e.g. Toll-like receptors, inflammasome receptors, and complement components initiate complex cellular cascades by recognizing or sensing different pathogen and damage-associated molecular patterns, respectively. Cytokines and chemokines represent alarm messages for leukocytes and once activated, these cells travel long distances to targeted inflamed tissues. Although it is a crucial survival mechanism, prolonged inflammation is detrimental and participates in numerous chronic age-related diseases. This article will review the onset of inflammation and link its functions to the pathogenesis of age-related macular degeneration (AMD), which is the leading cause of severe vision loss in aged individuals in the developed countries. In this progressive disease, degeneration of the retinal pigment epithelium (RPE) results in the death of photoreceptors, leading to a loss of central vision. The RPE is prone to oxidative stress, a factor that together with deteriorating functionality, e.g. decreased intracellular recycling and degradation due to attenuated heterophagy/autophagy, induces inflammation. In the early phases, accumulation of intracellular lipofuscin in the RPE and extracellular drusen between RPE cells and Bruch's membrane can be clinically detected. Subsequently, in dry (atrophic) AMD there is geographic atrophy with discrete areas of RPE loss whereas in the wet (exudative) form there is neovascularization penetrating from the choroid to retinal layers. Elevations in levels of local and systemic biomarkers indicate that chronic inflammation is involved in the pathogenesis of both disease forms.

  15. Characterizing depth-dependent refractive index of articular cartilage subjected to mechanical wear or enzymic degeneration

    NASA Astrophysics Data System (ADS)

    Wang, Kuyu; Wu, Jianping; Day, Robert; Kirk, Thomas Brett; Hu, Xiaozhi

    2016-09-01

    Utilizing a laser scanning confocal microscope system, the refractive indices of articular cartilage (AC) with mechanical or biochemical degenerations were characterized to investigate whether potential correlations exist between refractive index (RI) and cartilage degeneration. The cartilage samples collected from the medial femoral condyles of kangaroo knees were mechanically degenerated under different loading patterns or digested in trypsin solution with different concentrations. The sequences of RI were then measured from cartilage surface to deep region and the fluctuations of RI were quantified considering combined effects of fluctuating frequency and amplitude. The compositional and microstructural alterations of cartilage samples were assessed with histological methods. Along with the loss of proteoglycans, the average RI of cartilage increased and the local fluctuation of RI became stronger. Short-term high-speed test induced little influence to both the depth fluctuation and overall level of RI. Long-term low-speed test increased the fluctuation of RI but the average RI was barely changed. The results substantially demonstrate that RI of AC varies with both compositional and structural alterations and is potentially an indicator for the degeneration of AC.

  16. Transneuronal Degeneration of Thalamic Nuclei following Middle Cerebral Artery Occlusion in Rats

    PubMed Central

    2016-01-01

    Objective. Postinfarction transneuronal degeneration refers to secondary neuronal death that occurs within a few days to weeks following the disruption of input or output to synapsed neurons sustaining ischemic insults. The thalamus receives its blood supply from the posterior circulation; however, infarctions of the middle cerebral arterial may cause secondary transneuronal degeneration in the thalamus. In this study, we presented the areas of ischemia and associated transneuronal degeneration following MCAo in a rat model. Materials and Methods. Eighteen 12-week-old male Sprague-Dawley rats were randomly assigned to receive middle cerebral artery occlusion surgery for 1, 7, and 14 days. Cerebral atrophy was assessed by 2,3,5-triphenyltetrazolium hydrochloride staining. Postural reflex and open field tests were performed prior to animal sacrifice to assess the effects of occlusion on behavior. Results. Myelin loss was observed at the lesion site following ischemia. Gliosis was also observed in thalamic regions 14 days following occlusion. Differential degrees of increased vascular endothelial growth factor expression were observed at each stage of infarction. Increases in myelin basic protein levels were also observed in the 14-day group. Conclusion. The present rat model of ischemia provides evidence of transneuronal degeneration within the first 14 days of occlusion. The observed changes in protein expression may be associated with self-repair mechanisms in the damaged brain. PMID:27597962

  17. Interobserver error in interpretation of the radiographs for degeneration of the lumbar spine.

    PubMed

    Madan, Sanjeev S; Rai, Am; Harley, John M

    2003-01-01

    We examined 114 segments in 23 patients' lumbar spine plain radiographs affected by disc degeneration. Two consultant orthopaedic surgeons, two consultant radiologists, and one spine nurse practitioner made independent observations on the radiographs. MRI scan films of the corresponding 114 segments were used as a gold standard. Kappa coefficients were used to evaluate the interobserver error, and the error between the independent observers and the MRI scanning reports. The systematic differences between the observers for the diagnosis of the disc degeneration at each segment level was recorded. There was significant interobserver error between the independent observers. The pairwise interobserver agreement ranged from fair to substantial on the plain radiograph observations [Weighted kappa coefficient, mean: 0.517 (CI=0.388-0.646)]. The pairwise interobserver agreement between the independent observers and the MRI scan ranged from fair to moderate [Weighted kappa coefficient, mean: 0.388 (CI=0.259-0.518)]. There is significant error in interpretation of the plain radiographs for the diagnosis of lumbar disc degeneration. MRI may be more accurate in the diagnosis of lumbar disc degeneration.

  18. Multi-Disciplinary, Multi-Fidelity Discrete Data Transfer Using Degenerate Geometry Forms

    NASA Technical Reports Server (NTRS)

    Olson, Erik D.

    2016-01-01

    In a typical multi-fidelity design process, different levels of geometric abstraction are used for different analysis methods, and transitioning from one phase of design to the next often requires a complete re-creation of the geometry. To maintain consistency between lower-order and higher-order analysis results, Vehicle Sketch Pad (OpenVSP) recently introduced the ability to generate and export several degenerate forms of the geometry, representing the type of abstraction required to perform low- to medium-order analysis for a range of aeronautical disciplines. In this research, the functionality of these degenerate models was extended, so that in addition to serving as repositories for the geometric information that is required as input to an analysis, the degenerate models can also store the results of that analysis mapped back onto the geometric nodes. At the same time, the results are also mapped indirectly onto the nodes of lower-order degenerate models using a process called aggregation, and onto higher-order models using a process called disaggregation. The mapped analysis results are available for use by any subsequent analysis in an integrated design and analysis process. A simple multi-fidelity analysis process for a single-aisle subsonic transport aircraft is used as an example case to demonstrate the value of the approach.

  19. Interobserver Error in Interpretation of the Radiographs for Degeneration of the Lumbar Spine

    PubMed Central

    Madan, Sanjeev S; Rai, Am; Harley, John M

    2003-01-01

    We examined 114 segments in 23 patients' lumbar spine plain radiographs affected by disc degeneration. Two consultant orthopaedic surgeons, two consultant radiologists, and one spine nurse practitioner made independent observations on the radiographs. MRI scan films of the corresponding 114 segments were used as a gold standard. Kappa coefficients were used to evaluate the interobserver error, and the error between the independent observers and the MRI scanning reports. The systematic differences between the observers for the diagnosis of the disc degeneration at each segment level was recorded. There was significant interobserver error between the independent observers. The pairwise interobserver agreement ranged from fair to substantial on the plain radiograph observations [Weighted kappa coefficient, mean: 0.517 (CI=0.388-0.646)]. The pairwise interobserver agreement between the independent observers and the MRI scan ranged from fair to moderate [Weighted kappa coefficient, mean: 0.388 (CI=0.259-0.518)]. There is significant error in interpretation of the plain radiographs for the diagnosis of lumbar disc degeneration. MRI may be more accurate in the diagnosis of lumbar disc degeneration. PMID:14575250

  20. Prevention of age-related macular degeneration

    PubMed Central

    Koo, Simon Chi Yan; Chan, Clement Wai Nang

    2010-01-01

    Age-related macular degeneration (AMD) is one of the leading causes of blindness in the developed world. Although effective treatment modalities such as anti-VEGF treatment have been developed for neovascular AMD, there is still no effective treatment for geographical atrophy, and therefore the most cost-effective management of AMD is to start with prevention. This review looks at current evidence on preventive measures targeted at AMD. Modalities reviewed include (1) nutritional supplements such as the Age-Related Eye Disease Study (AREDS) formula, lutein and zeaxanthin, omega-3 fatty acid, and berry extracts, (2) lifestyle modifications, including smoking and body-mass-index, and (3) filtering sunlight, i.e. sunglasses and blue-blocking intraocular lenses. In summary, the only proven effective preventive measures are stopping smoking and the AREDS formula. PMID:20862519

  1. Odor identification in frontotemporal lobar degeneration subtypes.

    PubMed

    Magerova, Hana; Vyhnalek, Martin; Laczo, Jan; Andel, Ross; Rektorova, Irena; Kadlecova, Alexandra; Bojar, Martin; Hort, Jakub

    2014-12-01

    Odor identification impairment is a feature of several neurodegenerative disorders. Although neurodegenerative changes in the frontotemporal lobar degeneration (FTLD) subtypes involve areas important for olfactory processing, data on olfactory function in these patients are limited. An 18-item, multiple-choice odor identification test developed at our memory clinic, the Motol Hospital smell test, was administered to 9 patients with behavioral variant frontotemporal dementia, 13 patients with the language variants, primary nonfluent aphasia (n = 7) and semantic dementia (n = 6), and 8 patients with progressive supranuclear palsy. Compared to the control group (n = 15), all FTLD subgroups showed significant impairment of odor identification (P < .05). The differences between the FTLD subgroups were not significant. No correlation between odor identification and neuropsychological tests results was found. Our data suggest that odor identification impairment is a symptom common to FTLD syndromes, and it seems to be based on olfactory structure damage rather than cognitive decline.

  2. Generalized sheath criterion for arbitrary degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2017-01-01

    In this research, we study the generalized sheath criterion for plasmas with an arbitrary degree of electron degeneracy and temperature, ranging from the classical dilute regime to the fully degenerate quantum plasmas. The latter may be relevant to warm dense matter and/or laboratory high energy density matter or even astrophysical stellar plasmas. The hydrostatic one dimensional model is used to establish the generalized Bohm's criterion for sheath entrance ion speed limits, and the small amplitude theory of the sheath problem, which accurately describes the sheath parameters for lower ion acoustic Mach numbers, is developed. Our results indicate that the sheath characteristic parameters such as electrostatic potential and density profiles, as well as the wall potential and the sheath length, are significantly affected by plasma parameters such as the ion and electron temperature and number densities in the plasma region. In particular, there are fundamental differences between sheath structures of the dilute classical plasmas and those of dense quantum ones.

  3. Degenerate R-S perturbation theory

    NASA Technical Reports Server (NTRS)

    Hirschfelder, J. O.; Certain, P. R.

    1973-01-01

    A concise, systematic procedure is given for determining the Rayleigh-Schrodinger energies and wave functions of degenerate states to arbitrarily high orders even when the degeneracies of the various states are resolved in arbitrary orders. The procedure is expressed in terms of an iterative cycle in which the energy through the (2n+1)st order is expressed in terms of the partially determined wave function through the n-th order. Both a direct and an operator derivation are given. The two approaches are equivalent and can be transcribed into each other. The direct approach deals with the wave functions (without the use of formal operators) and has the advantage that it resembles the usual treatment of nondegenerate perturbations and maintains close contact with the basic physics. In the operator approach, the wave functions are expressed in terms of infinite order operators which are determined by the successive resolution of the space of the zeroth order functions.

  4. Odour Identification in Frontotemporal Lobar Degeneration

    PubMed Central

    Rami, Lorena; Loy, Clement T.; Hailstone, Julia; Warren, Jason D.

    2008-01-01

    Little information is available concerning olfactory processing in frontotemporal lobar degeneration (FTLD). We undertook a case-control study of olfactory processing in three male patients fulfilling clinical criteria for FTLD. Odour identification (semantic analysis) and odour discrimination (perceptual analysis) were investigated using tests adapted from the University of Pennsylvania Smell Identification Test. General neuropsychometry and structural volumetric brain magnetic resonance imaging (MRI) were also performed. The three patients with FTLD exhibited a disorder of olfactory processing with the characteristics of a predominantly semantic (odour identification) deficit. This olfactory deficit was more prominent in patients with greater involvement of the temporal lobes on MRI. Central deficits of odour identification may be more common in FTLD than previously recognised, and these deficits may assist in clinical characterisation. PMID:17380245

  5. Degenerate polygonal tilings in simple animal tissues

    NASA Astrophysics Data System (ADS)

    Hočevar, A.; Ziherl, P.

    2009-07-01

    The salient feature of one-cell-thick epithelia is their en face view, which reveals the polygonal cross section of the close-packed prismatic cells. The physical mechanisms that shape these tissues were hitherto explored using theories based on cell proliferation, which were either entirely topological or included certain morphogenetic forces. But mitosis itself may not be instrumental in molding the tissue. We show that the structure of simple epithelia can be explained by an equilibrium model where energy-degenerate polygons in an entropy-maximizing tiling are described by a single geometric parameter encoding their inflatedness. The two types of tilings found numerically—ordered and disordered—closely reproduce the patterns observed in Drosophila, Hydra, and Xenopus and they generalize earlier theoretical results. Free of a specific cell self-energy, cell-cell interaction, and cell division kinetics, our model provides an insight into the universality of living and inanimate two-dimensional cellular structures.

  6. Crystallization and collapse in relativistically degenerate matter

    SciTech Connect

    Akbari-Moghanjoughi, M.

    2013-04-15

    In this paper, it is shown that a mass density limit exists beyond which the relativistically degenerate matter would crystallize. The mass density limit, found here, is quite analogous to the mass limit predicted by Chandrasekhar for a type of compact stars called white dwarfs (M{sub Ch} Asymptotically-Equal-To 1.43 Solar Mass). In this study, the old problem of white dwarf core collapse, which has been previously investigated by Chandrasekhar using hydrostatic stability criteria, is revisited in the framework of the quantum hydrodynamics model by inspection of the charge screening at atomic scales in the relativistic degeneracy plasma regime taking into account the relativistic Fermi-Dirac statistics and electron interaction features such as the quantum statistical pressure, Coulomb attraction, electron exchange-correlation, and quantum recoil effects. It is revealed that the existence of ion correlation and crystallization of matter in the relativistically degenerate plasma puts a critical mass density limit on white dwarf core region. It is shown that a white dwarf star with a core mass density beyond this critical limit can undergo the spontaneous core collapse (SCC). The SCC phenomenon, which is dominantly caused by the electron quantum recoil effect (interference and localization of the electron wave function), leads to a new exotic state of matter. In such exotic state, the relativistic electron degeneracy can lead the white dwarf crystallized core to undergo the nuclear fusion and an ultimate supernova by means of the volume reduction (due to the enhanced compressibility) and huge energy release (due to the increase in cohesive energy), under the stars huge inward gravitational pressure. Moreover, it is found that the SCC phenomenon is significantly affected by the core composition (it is more probable for heavier plasmas). The critical mass density found here is consistent with the values calculated for core density of typical white dwarf stars.

  7. Retrograde Axonal Degeneration in Parkinson Disease

    PubMed Central

    Tagliaferro, Patricia; Burke, Robert E.

    2016-01-01

    In spite of tremendous research efforts we have not yet achieved two of our principal therapeutic goals in the treatment of Parkinson’s disease (PD), to prevent its onward progression and to provide restoration of systems that have already been damaged by the time of diagnosis. There are many possible reasons for our inability to make progress. One possibility is that our efforts thus far may not have been directed towards the appropriate cellular compartments. Up until now research has been largely focused on the loss of neurons in the disease. Thus, neuroprotection approaches have been largely aimed at blocking mechanisms that lead to destruction of the neuronal cell body. Attempts to provide neurorestoration have been almost entirely focused on replacement of neurons. We herein review the evidence that the axonal component of diseased neuronal systems merit more of our attention. Evidence from imaging studies, from postmortem neurochemical studies, and from genetic animal models suggests that the axons of the dopaminergic system are involved predominantly and early in PD. Since the mechanisms of axonal destruction are distinct from those of neuron cell body degeneration, a focus on axonal neurobiology will offer new opportunities for preventing their degeneration. At present these mechanisms remain largely obscure. However, defining them is likely to offer new opportunities for neuroprotection. In relation to neurorestoration, while it has been classically believed that neurons of the adult central nervous system are incapable of new axon growth, recent evidence shows that this is not true for the dopaminergic projection. In conclusion, the neurobiology of axons is likely to offer many new approaches to protective and restorative therapeutics. PMID:27003783

  8. Crystallization and collapse in relativistically degenerate matter

    NASA Astrophysics Data System (ADS)

    Akbari-Moghanjoughi, M.

    2013-04-01

    In this paper, it is shown that a mass density limit exists beyond which the relativistically degenerate matter would crystallize. The mass density limit, found here, is quite analogous to the mass limit predicted by Chandrasekhar for a type of compact stars called white dwarfs (MCh≃1.43 Solar Mass). In this study, the old problem of white dwarf core collapse, which has been previously investigated by Chandrasekhar using hydrostatic stability criteria, is revisited in the framework of the quantum hydrodynamics model by inspection of the charge screening at atomic scales in the relativistic degeneracy plasma regime taking into account the relativistic Fermi-Dirac statistics and electron interaction features such as the quantum statistical pressure, Coulomb attraction, electron exchange-correlation, and quantum recoil effects. It is revealed that the existence of ion correlation and crystallization of matter in the relativistically degenerate plasma puts a critical mass density limit on white dwarf core region. It is shown that a white dwarf star with a core mass density beyond this critical limit can undergo the spontaneous core collapse (SCC). The SCC phenomenon, which is dominantly caused by the electron quantum recoil effect (interference and localization of the electron wave function), leads to a new exotic state of matter. In such exotic state, the relativistic electron degeneracy can lead the white dwarf crystallized core to undergo the nuclear fusion and an ultimate supernova by means of the volume reduction (due to the enhanced compressibility) and huge energy release (due to the increase in cohesive energy), under the stars huge inward gravitational pressure. Moreover, it is found that the SCC phenomenon is significantly affected by the core composition (it is more probable for heavier plasmas). The critical mass density found here is consistent with the values calculated for core density of typical white dwarf stars.

  9. Early degeneration of the cerebellar cortex, particularly the granular cells.

    PubMed

    Bugiani, O; Berio, A; Di Stefano, A; Mangiante, G; Mancardi, G L; Leonardi, A

    1978-12-07

    An 8 month old infant, who died of severe gastroenteritis, presented a degeneration of the cerebellar cortex involving cells arising from the outer granular layer as well as Purkinje and Golgi II cells. Residual Purkinje cells showed vacuolar change of the cell body and dendritic abnormalities. Related lesions were atrophy of the inferior olives and degeneration of the mossy fibers.

  10. Involvement of lysosomes in the early stages of axon degeneration.

    PubMed

    Zheng, Jin; Yan, Tingting; Feng, Yan; Zhai, Qiwei

    2010-02-01

    Axon degeneration is a common hallmark of many neurodegenerative diseases, and the underlying mechanism remains largely unknown. Lysosomes are involved in some neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Whether lysosomes are involved in axon degeneration is yet to be elucidated. In this study, we found only about 10% lysosomes remained in axons of cultured superior cervical ganglia (SCGs) after transection for 4h when stained with LysoTracker. Furthermore, we found that lysosomal disruption occurred earlier than morphological changes and loss of mitochondrial membrane potential. In addition, the well-known axon-protective protein Wld(S) delayed injury-induced axon degeneration from both morphological changes and lysosomal disruption. Lysosomal inhibitors including chloroquine and ammonium chloride induced axon degeneration in cultured SCGs, and Wld(S) also slowed down the axon degeneration induced by lysosomal inhibitors. All these data suggest that lysosomal disruption is an early marker of axon degeneration, and inhibition of lysosome induces axon degeneration in a Wld(S)-protectable way. Thus, maintenance of normal lysosomal function might be an important approach to delay axon degeneration in neurodegenerative diseases.

  11. 9 CFR 311.35 - Muscular inflammation, degeneration, or infiltration.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Muscular inflammation, degeneration, or infiltration. 311.35 Section 311.35 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE... PARTS § 311.35 Muscular inflammation, degeneration, or infiltration. (a) If muscular lesions are...

  12. [Depression in Patients with Age-Related Macular Degeneration].

    PubMed

    Narváez, Yamile Reveiz; Gómez-Restrepo, Carlos

    2012-09-01

    Age-related macular degeneration is a cause for disability in the elderly since it greatly affects their quality of life and increases depression likelihood. This article discusses the negative effect depression has on patients with age-related macular degeneration and summarizes the interventions available for decreasing their depression index.

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

    PubMed Central

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

    2013-01-01

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

  14. Anomalous skin effects in a weakly magnetized degenerate electron plasma

    NASA Astrophysics Data System (ADS)

    Abbas, G.; Sarfraz, M.; Shah, H. A.

    2014-09-01

    Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate electron plasma is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. Plasmas 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian plasma case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate plasma is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of Plasma Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].

  15. Anomalous skin effects in a weakly magnetized degenerate electron plasma

    SciTech Connect

    Abbas, G. Sarfraz, M.; Shah, H. A.

    2014-09-15

    Fully relativistic analysis of anomalous skin effects for parallel propagating waves in a weakly magnetized degenerate electron plasma is presented and a graphical comparison is made with the results obtained using relativistic Maxwellian distribution function [G. Abbas, M. F. Bashir, and G. Murtaza, Phys. Plasmas 18, 102115 (2011)]. It is found that the penetration depth for R- and L-waves for degenerate case is qualitatively small in comparison with the Maxwellian plasma case. The quantitative reduction due to weak magnetic field in the skin depth in R-wave for degenerate plasma is large as compared to the non-degenerate one. By ignoring the ambient magnetic field, previous results for degenerate field free case are salvaged [A. F. Alexandrov, A. S. Bogdankevich, and A. A. Rukhadze, Principles of Plasma Electrodynamics (Springer-Verlag, Berlin/Heidelberg, 1984), p. 90].

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

    PubMed

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

    2014-07-01

    Various biomechanical investigations have attempted to clarify the aetiology of adjacent segment disease (ASD). However, no biomechanical study has examined in detail the deformation behaviour of the adjacent segments when both pure torque and an angular displacement load are applied to the vertebrae along multiple segments. The purpose of this study is to investigate the biomechanical effects of pedicle screw fixation on adjacent segments. Ten cadaveric lumbar spines (L2-L5) of boars were used. Control and fusion models were prepared by disc damage and pedicle screw fixation of each specimen, and then, bending and rotation tests were performed using a six-axis material tester. In the biomechanical tests regulated by an angular displacement load, the range of motion (ROM) of the cranial and caudal adjacent segments in antero-posterior flexion and lateral bending was increased by about 20 % (p < 0.05), and the maximal torque in the fusion model was about threefold (p < 0.05) that in the control model. And in axial rotation, the ROM of cranial and caudal adjacent segments was increased by about 100 % (p < 0.001), and the maximal torque was about sixfold (p < 0.01) that in the control model. The ROM of adjacent segments was significantly increased after pedicle screw fixation as assessed by biomechanical tests regulated by an angular displacement load, but not in those regulated by torque. We present the results of biomechanical tests regulated by torque and angular displacement and show that the maximum torque of the fusion model was larger than that of the control model in the biomechanical test regulated by an angular displacement load, suggesting that mechanical stress on the segments adjacent to the fused segment is large. We think that ASD arises after spinal fusion surgery as a mechanism to compensate for the ROM lost due to excessive fusion by pedicle screw fixation, so that a large torque may be applied to adjacent segments within a physiologically

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

    PubMed Central

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

    2013-01-01

    Study Design Cross sectional and observational. Purpose To evaluate the different aspects of lumbar disc degenerative disc disease and relate them with magnetic resonance image (MRI) findings and symptoms. Overview of Literature Lumbar disc degenerative disease has now been proven as the most common cause of low back pain throughout the world. It may present as disc herniation, lumbar spinal stenosis, facet joint arthropathy or any combination. Presenting symptoms of lumbar disc degeneration are lower back pain and sciatica which may be aggravated by standing, walking, bending, straining and coughing. Methods This study was conducted from January 2012 to June 2012. Study was conducted on the diagnosed patients of lumbar disc degeneration. Diagnostic criteria were based upon abnormal findings in MRI. Patients with prior back surgery, spine fractures, sacroiliac arthritis, metabolic bone disease, spinal infection, rheumatoid arthritis, active malignancy, and pregnancy were excluded. Results During the targeted months, 163 patients of lumbar disc degeneration with mean age of 43.92±11.76 years, came into Neurosurgery department. Disc degeneration was most commonly present at the level of L4/L5 105 (64.4%).Commonest types of disc degeneration were disc herniation 109 (66.9%) and lumbar spinal stenosis 37 (22.7%). Spondylolisthesis was commonly present at L5/S1 10 (6.1%) and associated mostly with lumbar spinal stenosis 7 (18.9%). Conclusions Results reported the frequent occurrence of lumbar disc degenerative disease in advance age. Research efforts should endeavor to reduce risk factors and improve the quality of life. PMID:24353850

  18. Laplacian versus adjacency matrix in quantum walk search

    NASA Astrophysics Data System (ADS)

    Wong, Thomas G.; Tarrataca, Luís; Nahimov, Nikolay

    2016-10-01

    A quantum particle evolving by Schrödinger's equation contains, from the kinetic energy of the particle, a term in its Hamiltonian proportional to Laplace's operator. In discrete space, this is replaced by the discrete or graph Laplacian, which gives rise to a continuous-time quantum walk. Besides this natural definition, some quantum walk algorithms instead use the adjacency matrix to effect the walk. While this is equivalent to the Laplacian for regular graphs, it is different for non-regular graphs and is thus an inequivalent quantum walk. We algorithmically explore this distinction by analyzing search on the complete bipartite graph with multiple marked vertices, using both the Laplacian and adjacency matrix. The two walks differ qualitatively and quantitatively in their required jumping rate, runtime, sampling of marked vertices, and in what constitutes a natural initial state. Thus the choice of the Laplacian or adjacency matrix to effect the walk has important algorithmic consequences.

  19. Retinal Pre-Conditioning by CD59a Knockout Protects against Light-Induced Photoreceptor Degeneration

    PubMed Central

    Wilson, Brooks; Zhao, Liangliang; Bhuyan, Rupak; Bandyopadhyay, Mausumi; Lyubarsky, Arkady; Yu, Chen; Li, Yafeng; Kanu, Levi; Miwa, Takashi; Song, Wen-Chao; Finnemann, Silvia C.; Rohrer, Bärbel; Dunaief, Joshua L.

    2016-01-01

    Complement dysregulation plays a key role in the pathogenesis of age-related macular degeneration (AMD), but the specific mechanisms are incompletely understood. Complement also potentiates retinal degeneration in the murine light damage model. To test the retinal function of CD59a, a complement inhibitor, CD59a knockout (KO) mice were used for light damage (LD) experiments. Retinal degeneration and function were compared in WT versus KO mice following light damage. Gene expression changes, endoplasmic reticulum (ER) stress, and glial cell activation were also compared. At baseline, the ERG responses and rhodopsin levels were lower in CD59aKO compared to wild-type (WT) mice. Following LD, the ERG responses were better preserved in CD59aKO compared to WT mice. Correspondingly, the number of photoreceptors was higher in CD59aKO retinas than WT controls after LD. Under normal light conditions, CD59aKO mice had higher levels than WT for GFAP immunostaining in Müller cells, mRNA and protein levels of two ER-stress markers, and neurotrophic factors. The reduction in photon capture, together with the neurotrophic factor upregulation, may explain the structural and functional protection against LD in the CD59aKO. PMID:27893831

  20. Bmp6 Regulates Retinal Iron Homeostasis and Has Altered Expression in Age-Related Macular Degeneration

    PubMed Central

    Hadziahmetovic, Majda; Song, Ying; Wolkow, Natalie; Iacovelli, Jared; Kautz, Leon; Roth, Marie-Paule; Dunaief, Joshua L.

    2011-01-01

    Iron-induced oxidative stress causes hereditary macular degeneration in patients with aceruloplasminemia. Similarly, retinal iron accumulation in age-related macular degeneration (AMD) may exacerbate the disease. The cause of retinal iron accumulation in AMD is poorly understood. Given that bone morphogenetic protein 6 (Bmp6) is a major regulator of systemic iron, we examined the role of Bmp6 in retinal iron regulation and in AMD pathogenesis. Bmp6 was detected in the retinal pigment epithelium (RPE), a major site of pathology in AMD. In cultured RPE cells, Bmp6 was down-regulated by oxidative stress and up-regulated by iron. Intraocular Bmp6 protein injection in mice up-regulated retinal hepcidin, an iron regulatory hormone, and altered retinal labile iron levels. Bmp6−/− mice had age-dependent retinal iron accumulation and degeneration. Postmortem RPE from patients with early AMD exhibited decreased Bmp6 levels. Because oxidative stress is associated with AMD pathogenesis and down-regulates Bmp6 in cultured RPE cells, the diminished Bmp6 levels observed in RPE cells in early AMD may contribute to iron build-up in AMD. This may in turn propagate a vicious cycle of oxidative stress and iron accumulation, exacerbating AMD and other diseases with hereditary or acquired iron excess. PMID:21703414

  1. Late degeneration in rabbit tissues after irradiation by heavy ions

    NASA Technical Reports Server (NTRS)

    Lett, J. T.; Cox, A. B.; Keng, P. C.; Lee, A. C.; Su, C. M.; Bergtold, D. S.

    1980-01-01

    Results are presented for investigations of the late effects of heavy-ion irradiation on rabbit tissues which were undertaken to assess the hazards associated with the long-term exposure of humans to heavy ions in space during such activities as the construction of solar power stations or voyages to Mars. White rabbits approximately six weeks old were exposed to various doses of collimated beams of 400-MeV/n Ne ions, 570 MeV/n Ar ions and Co-60 gamma rays directed through both eyes, and the responses of the various tissues (hair follicles, skin, cornea, lens, retina, Harderian glands, bone and forebrain) were examined. Proliferating tissues are found to exhibit high damage levels in the early and late periods following irradiation, while terminally differentiating tissues repond to radiation most intensely in the late period, years after irradiation, with no intermediate recovery. The results obtained from rabbits are used to predict the occurrence of late tissue degeneration in the central nervous system, terminally differentiating systems and stem cells of humans one or more decades following exposure to radiation levels anticipated during long-duration space flights. The studies also indicate that tissues may be prematurely aged in the sense that tissue life spans may be shortened without the development of malignancies.

  2. Parainflammation, chronic inflammation and age-related macular degeneration

    PubMed Central

    Chen, Mei; Xu, Heping

    2016-01-01

    Inflammation is an adaptive response of the immune system to noxious insults to maintain homeostasis and restore functionality. The retina is considered an immune privileged tissue due to its unique anatomical and physiological properties. During aging, the retina suffers from a low-grade chronic oxidative insult, which sustains for decades and increases in level with advancing age. As a result, the retinal innate immune system, particularly microglia and the complement system, undergo low levels of activation (para-inflammation). In many cases, this para-inflammatory response can maintain homeostasis in the healthy aging eye. However, in patients with age-related macular degeneration (AMD), this para-inflammatory response becomes dysregulated and contributes to macular damage. Factors contributing to the dysregulation of age-related retinal para-inflammation include genetic predisposition, environmental risk factors and old age. Dysregulated para-inflammation (chronic inflammation) in AMD damages the blood retina barrier (BRB), resulting in the breach of retinal immune privilege leading to the development of retinal lesions. This review discusses the basic principles of retinal innate immune responses to endogenous chronic insults in normal aging and in AMD, and explores the difference between beneficial para-inflammation and the detrimental chronic inflammation in the context of AMD. PMID:26292978

  3. Angiogenesis in the degeneration of the lumbar intervertebral disc

    PubMed Central

    David, Gh; Iencean, SM; Mohan, A

    2010-01-01

    The goal of the study is to show the histological and biochemical changes that indicate the angiogenesis of the intervertebral disc in lumbar intervertebral disc hernia and the existence of epidemiological correlations between these changes and the risk factors of lumbar intervertebral disc hernia, as well as the patient's quality of life (QOL). We have studied 50 patients aged between 18 and 73 years old, who have undergone lumbar intervertebral disc hernia surgery, making fibroblast growth factor and vascular endothelial growth factor level measurements, as elements in the process of appreciating the disc angiogenesis. Also, pre–surgery and post–surgery QOL has been measured, as well as the intensity of the pain syndrome. We have identified factors capable of stimulating vascular endothelial growth (VEGF, FGF–2) for the examined disc material, but histological examination did not show angiogenesis. The process of angiogenesis at the degenerated intervertebral disc level affects the patient's quality of life both pre and postoperatively, and may be a predictive factor for the post–operative results. Patients can prevent the appearance of angiogenesis type degenerative processes of the intervertebral disc by avoiding angiogenesis correlated factors (weight control, physical effort, and smoking). PMID:20968201

  4. Modeling fires in adjacent ship compartments with computational fluid dynamics

    SciTech Connect

    Wix, S.D.; Cole, J.K.; Koski, J.A.

    1998-05-10

    This paper presents an analysis of the thermal effects on radioactive (RAM) transportation packages with a fire in an adjacent compartment. An assumption for this analysis is that the adjacent hold fire is some sort of engine room fire. Computational fluid dynamics (CFD) analysis tools were used to perform the analysis in order to include convective heat transfer effects. The analysis results were compared to experimental data gathered in a series of tests on tile US Coast Guard ship Mayo Lykes located at Mobile, Alabama.

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

    PubMed

    Kepler, Christopher K; Hilibrand, Alan S

    2012-01-01

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

  6. Degenerate Fermi gas perturbations at standard background cosmology

    SciTech Connect

    Bernardini, A.E.; Perico, E.L.D. E-mail: elduarte@ifi.unicamp.br

    2011-01-01

    The hypothesis of a tiny fraction of the cosmic inventory evolving cosmologically as a degenerate Fermi gas test fluid at some dominant cosmological background is investigated. Our analytical results allow for performing preliminary computations to the evolution of perturbations for relativistic and non-relativistic test fluids. The density fluctuation, δ, the fluid velocity divergence, θ, and an explicit expression for the dynamics of the shear stress, σ, are obtained for a degenerate Fermi gas in the background regime of radiation. Extensions to the dominance of matter and to the ΛCDM cosmological background are also investigated and lessons concerning the formation of large structures of degenerate Fermi gas are depicted.

  7. Case report 872. "Ancient" schwannoma (degenerated neurilemoma).

    PubMed

    Schultz, E; Sapan, M R; McHeffey-Atkinson, B; Naidich, J B; Arlen, M

    1994-10-01

    A case of an ancient schwannoma was presented. The rare occurrence of this tumor has resulted in only a few reported cases with descriptions of its features on imaging. Our patient's tumor, like one previously reported case, demonstrated calcification on the plain film - a finding not associated with other histologic types of schwannomas. Angiography revealed the tumor to be hypervascular. Evaluation by MRI demonstrated a lobulated, encapsulated soft tissue mass containing several cystic areas that corresponded histologically to areas of necrosis. Hypertrophied blood vessels were seen in the periphery of the tumoral mass. Too few ancient schwannomas have been reported to conclude whether or not radiographic evidence of soft tissue calcification is characteristic of this histologically distinctive subtype of schwannoma. However, since calcification is seen histologically as part of the degenerating process, its presence on plain films could be a feature of this tumor. Furthermore, the presence of cystic areas on MRI is not surprising given the pathological changes that occur in this tumor. We suggest that a diagnosis of ancient schwannoma be considered when a patient presents with a hypervascular soft tissue mass containing amorphous calcification on plain films and cystic areas on MRI. Despite the nonspecificity of these imaging findings, this point is relevant because each of these features suggests the presence of a malignant mass. Awareness of the possibility of a benign ancient schwannoma could obviate unnecessary radical surgery.

  8. Quantum kinetic theories in degenerate plasmas

    NASA Astrophysics Data System (ADS)

    Brodin, Gert; Ekman, Robin; Zamanian, Jens

    2017-01-01

    In this review we give an overview of the recent work on quantum kinetic theories of plasmas. We focus, in particular, on the case where the electrons are fully degenerate. For such systems, perturbation methods using the distribution function can be problematic. Instead we present a model that considers the dynamics of the Fermi surface. The advantage of this model is that, even though the value of the distribution function can be greatly perturbed outside the equilibrium Fermi surface, deformation of the Fermi surface is small up to very large amplitudes. Next, we investigate the short-scale dynamics for which the Wigner-Moyal equation replaces the Vlasov equation. In particular, we study wave-particle interaction, and deduce that new types of wave damping can occur due to the simultaneous absorption (or emission) of multiple wave quanta. Finally, we consider exchange effects within a quantum kinetic formalism to find a model that is more accurate than those using exchange potentials from density functional theory. We deduce the exchange corrections to the dispersion relations for Langmuir and ion-acoustic waves. In comparison to results based on exchange potentials deduced from density functional theory we find that the latter models are reasonably accurate for Langmuir waves, but rather inaccurate for ion acoustic waves.

  9. An Interferometric Harvest of Double Degenerates

    NASA Astrophysics Data System (ADS)

    Nelan, Edmund

    2001-07-01

    The white dwarf {WD} mass and age distributions hold clues to the star formation history of our Galaxy and the age of the disk. To extract this information we need to carefully calibrate the WD mass-radius relation and the WD cooling curve. But to do so, we must directly determine the masses for a variety of WDs of different sub-types. The only direct method is through the orbital analysis of resolved WDs in non- interacting binary systems. Sadly, this has been done, with varying quality, for only 4 WDs {40 Eri B, Sirius B, Procyon B, and Stien 2051B}, mainly because it is extremely difficult to resolve WDs in binary systems with periods less than 50 years. We propose a high angular resolution Snapshot survey with FGS1r to observe cool WDs with the objective of discovering {resolving} double degenerate systems with modest separations and periods as short as 25 years, ideal binaries for follow up mass determinations. By carefully selecting our targets, about 10 such systems should be revealed. This will dramatically increase the number of WDs available for dynamical mass measurements {its 2 for 1.}, enabling a better calibration the WD mass-radius relation.

  10. Statistical physics of age related macular degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon; Mazzitello, K. I.; Arizmendi, C. M.; Grossniklaus, H. E.

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). The RPE is a phagocytic system that is essential for renewal of photoreceptors (rods and cones). With time, incompletely degraded membrane material builds up in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer disease and Parkinson disease. The study of lipofuscin formation and growth is important, because of their association with cellular aging. We introduce a model of non-equilibrium cluster growth and aggregation that we have developed for studying the formation and growth of lipofuscin in the aging RPE. Our results agree with a linear growth of the number of lipofuscin granules with age. We apply the dynamic scaling approach to our model and find excellent data collapse for the cluster size distribution. An unusual feature of our model is that while small particles are removed from the RPE the larger ones become fixed and grow by aggregation.

  11. Neurophysiology of central retinal degeneration in cat.

    PubMed

    Levick, W R; Thibos, L N

    1993-01-01

    Receptive fields of ganglion cells have been studied in cats possessing a chronic, arrested lesion of central retinal degeneration. Lesions were characterized by an ophthalmoscopically sharp border separating apparently normal retina from the region of the lesion. Under direct ophthalmoscopic guidance, a succession of recordings was obtained from ganglion cells having cell bodies at various positions relative to the lesion. Cells located more than 1 deg outside the ophthalmoscopic border had normal visual sensitivity as assessed by area-threshold experiments. Inside the lesion cells within 1 deg of the border had reduced sensitivity which often precluded functional classification by the usual visual tests. Ganglion cells located more than 1 deg inside the border of large lesions were blind and some had abnormal patterns of maintained discharge of action potentials. Nevertheless, the antidromic latencies of these blind cells fell into the familiar conduction groups (T1/T2/T3). Receptive-field maps of cells near the border of the lesion often appeared truncated, with the missing portion of the field covered by the lesion. These observations were consistent with the abnormal form of area-threshold curves. Although the responsiveness of cells near the lesion was abnormally low for grating stimuli, cutoff spatial frequency and orientation bias of these cells were within normal limits.

  12. Genetic Factors in Intervertebral Disc Degeneration

    PubMed Central

    Feng, Yi; Egan, Brian; Wang, Jinxi

    2016-01-01

    Low back pain (LBP) is a major cause of disability and imposes huge economic burdens on human society worldwide. Among many factors responsible for LBP, intervertebral disc degeneration (IDD) is the most common disorder and is a target for intervention. The etiology of IDD is complex and its mechanism is still not completely understood. Many factors such as aging, spine deformities and diseases, spine injuries, and genetic factors are involved in the pathogenesis of IDD. In this review, we will focus on the recent advances in studies on the most promising and extensively examined genetic factors associated with IDD in humans. A number of genetic defects have been correlated with structural and functional changes within the intervertebral disc (IVD), which may compromise the disc’s mechanical properties and metabolic activities. These genetic and proteomic studies have begun to shed light on the molecular basis of IDD, suggesting that genetic factors are important contributors to the onset and progression of IDD. By continuing to improve our understanding of the molecular mechanisms of IDD, specific early diagnosis and more effective treatments for this disabling disease will be possible in the future. PMID:27617275

  13. Physics of Age Related Macular Degeneration

    NASA Astrophysics Data System (ADS)

    Family, Fereydoon

    2009-11-01

    Age-related macular degeneration (AMD) is the leading cause of blindness beyond the age of 50 years. The most common pathogenic mechanism that leads to AMD is choroidal neovascularization (CNV). CNV is produced by accumulation of residual material caused by aging of retinal pigment epithelium cells (RPE). The RPE is a phagocytic system that is essential for renewal of photoreceptors (rods and cones). With time, incompletely degraded membrane material builds up in the form of lipofuscin. Lipofuscin is made of free-radical-damaged protein and fat, which forms not only in AMD, but also Alzheimer's disease, and Parkinson's disease. The study of lipofuscin formation and growth is important, because of their association with cellular aging. In this talk I will discuss a model of non-equilibrium cluster growth that we have developed for studying the formation and growth of lipofuscin in AMD [K.I. Mazzitello, C.M. Arizmendi, Fereydoon Family, H. E. Grossniklaus, Physical Review E (2009)]. I will also present an overview of our theoretical and computational efforts in modeling some other aspects of the physics of AMD, including CNV and the breakdown of Bruch's membrane [Ongoing collaboration with Abbas Shirinifard and James A. Glazier, Biocomplexity Institute and Department of Physics, Indiana University, Y. Jiang, Los Alamos, and Hans E. Grossniklaus, Department of Ophthalmology, Emory University].

  14. Linear stochastic degenerate Sobolev equations and applications†

    NASA Astrophysics Data System (ADS)

    Liaskos, Konstantinos B.; Pantelous, Athanasios A.; Stratis, Ioannis G.

    2015-12-01

    In this paper, a general class of linear stochastic degenerate Sobolev equations with additive noise is considered. This class of systems is the infinite-dimensional analogue of linear descriptor systems in finite dimensions. Under appropriate assumptions, the mild and strong well-posedness for the initial value problem are studied using elements of the semigroup theory and properties of the stochastic convolution. The final value problem is also examined and it is proved that this is uniquely strongly solvable and the solution is continuously dependent on the final data. Based on the results of the forward and backward problem, the conditions for the exact controllability are investigated for a special but important class of these equations. The abstract results are illustrated by applications in complex media electromagnetics, in the one-dimensional stochastic Dirac equation in the non-relativistic limit and in a potential application in input-output analysis in economics. Dedicated to Professor Grigoris Kalogeropoulos on the occasion of his seventieth birthday.

  15. Animal models of age related macular degeneration.

    PubMed

    Pennesi, Mark E; Neuringer, Martha; Courtney, Robert J

    2012-08-01

    Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations.

  16. Disruption in dopaminergic innervation during photoreceptor degeneration.

    PubMed

    Ivanova, Elena; Yee, Christopher W; Sagdullaev, Botir T

    2016-04-15

    Dopaminergic amacrine cells (DACs) release dopamine in response to light-driven synaptic inputs, and are critical to retinal light adaptation. Retinal degeneration (RD) compromises the light responsiveness of the retina and, subsequently, dopamine metabolism is impaired. As RD progresses, retinal neurons exhibit aberrant activity, driven by AII amacrine cells, a primary target of the retinal dopaminergic network. Surprisingly, DACs are an exception to this physiological change; DACs exhibit rhythmic activity in healthy retina, but do not burst in RD. The underlying mechanism of this divergent behavior is not known. It is also unclear whether RD leads to structural changes in DACs, impairing functional regulation of AII amacrine cells. Here we examine the anatomical details of DACs in three mouse models of human RD to determine how changes to the dopaminergic network may underlie physiological changes in RD. By using rd10, rd1, and rd1/C57 mice we were able to dissect the impacts of genetic background and the degenerative process on DAC structure in RD retina. We found that DACs density, soma size, and primary dendrite length are all significantly reduced. Using a novel adeno-associated virus-mediated technique to label AII amacrine cells in mouse retina, we observed diminished dopaminergic contacts to AII amacrine cells in RD mice. This was accompanied by changes to the components responsible for dopamine synthesis and release. Together, these data suggest that structural alterations of the retinal dopaminergic network underlie physiological changes during RD.

  17. Degenerate interfaces in antigen-antibody complexes.

    PubMed

    Decanniere, K; Transue, T R; Desmyter, A; Maes, D; Muyldermans, S; Wyns, L

    2001-10-26

    In most of the work dealing with the analysis of protein-protein interfaces, a single X-ray structure is available or selected, and implicitly it is assumed that this structure corresponds to the optimal complex for this pair of proteins. However, we have found a degenerate interface in a high-affinity antibody-antigen complex: the two independent complexes of the camel variable domain antibody fragment cAb-Lys3 and its antigen hen egg white lysozyme present in the asymmetric unit of our crystals show a difference in relative orientation between antibody and antigen, leading to important differences at the protein-protein interface. A third cAb-Lys3-hen lysozyme complex in a different crystal form adopts yet another relative orientation. Our results show that protein-protein interface characteristics can vary significantly between different specimens of the same high-affinity antibody-protein antigen complex. Consideration should be given to this type of observation when trying to establish general protein-protein interface characteristics.

  18. Animal models of age related macular degeneration

    PubMed Central

    Pennesi, Mark E.; Neuringer, Martha; Courtney, Robert J.

    2013-01-01

    Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations. PMID:22705444

  19. Producing Quantum Degenerate Gases of Strontium

    NASA Astrophysics Data System (ADS)

    Camargo, Francisco; Ding, Roger; Whalen, Joseph; Woehl, Germano; Dunning, Barry; Killian, Thomas

    2015-05-01

    We present our progress towards producing quantum degenerate gases of all four stable isotopes of strontium (84Sr, 86Sr, 87Sr, 88Sr) and isotopic mixtures. We characterize the performance of our broad-line (461 nm, 30.5 MHz), narrow-line (689 nm, 7.5 kHz) magneto-optical traps, and examine evaporative cooling for all four isotopes. The new apparatus will be used to create and study tunable long-range interactions by dressing with strongly-interacting Rydberg states. The ability to trap the four different isotopes allows a measure of control of these interactions through access to a range of attractive and repulsive interactions. Simultaneous trapping of different isotopes provides opportunities for novel laser cooling schemes for studying Bose-Bose and Bose-Fermi mixtures. Research supported by the AFOSR under grant no. FA9550-12-1-0267, the NSF under grants nos. 1301773 and 1205946, and the Robert A. Welch Foundation under grant no. C-0734.

  20. Computational molecular phenotyping of retinal sheet transplants to rats with retinal degeneration

    PubMed Central

    Seiler, M.J.; Jones, B.W.; Aramant, R.B.; Yang, P.B.; Keirstead, H.S.; Marc, R.E.

    2012-01-01

    Retinal progenitor sheet transplants have been shown to extend neuronal processes into a degenerating host retina and to restore visual responses in the brain. The aim of this study was the first attempt to identify cells involved in transplant signals to retinal degenerate hosts using computational molecular phenotyping (CMP). - S334ter line 3 rats received fetal retinal sheet transplants at the age of 24-40d. Donor tissues were incubated with slow-releasing microspheres containing BDNF or GDNF. Up to 265 days after surgery, eyes of selected rats were vibratome sectioned through the transplant area (some slices stained for donor marker hPAP), dehydrated and embedded in Eponate, sectioned into serial ultrathin datasets and probed for rhodopsin, cone opsin, CRALBP, L-glutamate, L-glutamine, glutathione, glycine, taurine, GABA, and DAPI. - In large transplant areas, photoreceptor outer segments in contact with host RPE revealed rod and cone opsin immunoreactivity whereas no such staining was found in the degenerate host retina. Transplant photoreceptor layers contained high taurine levels. Glutamate levels in the transplants were higher than in the host retina whereas GABA levels were similar. The transplant inner nuclear layer showed some loss of neurons, but amacrine cells and horizontal cells were not reduced. In many areas, glial hypertrophy between the host and transplant was absent and host and transplant neuropil appeared to intermingle. CMP data indicate that horizontal cells and both glycinergic and GABAergic amacrine cells are involved in a novel circuit between transplant and host, generating alternative signal pathways between transplant and degenerating host retina. PMID:22594836

  1. Inhibition of de novo ceramide biosynthesis by FTY720 protects rat retina from light-induced degeneration[S

    PubMed Central

    Chen, Hui; Tran, Julie-Thu A.; Eckerd, Annette; Huynh, Tuan-Phat; Elliott, Michael H.; Brush, Richard S.; Mandal, Nawajes A.

    2013-01-01

    Light-induced retinal degeneration (LIRD) in albino rats causes apoptotic photoreceptor cell death. Ceramide is a second messenger for apoptosis. We tested whether increases in ceramide mediate photoreceptor apoptosis in LIRD and if inhibition of ceramide synthesis protects the retina. Sprague-Dawley rats were exposed to 2,700 lux white light for 6 h, and the retinal levels of ceramide and its intermediary metabolites were measured by GC-MS or electrospray ionization tandem mass spectrometry. Enzymes of the de novo biosynthetic and sphingomyelinase pathways of ceramide generation were assayed, and gene expression was measured. The dosage and temporal effect of the ceramide synthase inhibitor FTY720 on the LIRD retina were measured by histological and functional analyses. Retinal ceramide levels increased coincident with the increase of dihydroceramide at various time points after light stress. Light stress in retina induces ceramide generation predominantly through the de novo pathway, which was prevented by systemic administration of FTY720 (10 mg/kg) leading to the protection of retinal structure and function. The neuroprotection of FTY720 was independent of its immunosuppressive action. We conclude that ceramide increase by de novo biosynthesis mediates photoreceptor apoptosis in the LIRD model and that inhibition of ceramide production protects the retina against light stress. PMID:23468130

  2. Spiral ganglion degeneration and hearing loss as a consequence of satellite cell death in saposin B-deficient mice.

    PubMed

    Akil, Omar; Sun, Ying; Vijayakumar, Sarath; Zhang, Wujuan; Ku, Tiffany; Lee, Chi-Kyou; Jones, Sherri; Grabowski, Gregory A; Lustig, Lawrence R

    2015-02-18

    Saposin B (Sap B) is an essential activator protein for arylsulfatase A in the hydrolysis of sulfatide, a lipid component of myelin. To study Sap B's role in hearing and balance, a Sap B-deficient (B(-/-)) mouse was evaluated. At both light and electron microscopy (EM) levels, inclusion body accumulation was seen in satellite cells surrounding spiral ganglion (SG) neurons from postnatal month 1 onward, progressing into large vacuoles preceding satellite cell degeneration, and followed by SG degeneration. EM also revealed reduced or absent myelin sheaths in SG neurons from postnatal month 8 onwards. Hearing loss was initially seen at postnatal month 6 and progressed thereafter for frequency-specific stimuli, whereas click responses became abnormal from postnatal month 13 onward. The progressive hearing loss correlated with the accumulation of inclusion bodies in the satellite cells and their subsequent degeneration. Outer hair cell numbers and efferent function measures (distortion product otoacoustic emissions and contralateral suppression) were normal in the B(-/-) mice throughout this period. Alcian blue staining of SGs demonstrated that these inclusion bodies corresponded to sulfatide accumulation. In contrast, changes in the vestibular system were much milder, but caused severe physiologic deficits. These results demonstrate that loss of Sap B function leads to progressive sulfatide accumulation in satellite cells surrounding the SG neurons, leading to satellite cell degeneration and subsequent SG degeneration with a resultant loss of hearing. Relative sparing of the efferent auditory and vestibular neurons suggests that alternate glycosphingolipid metabolic pathways predominate in these other systems.

  3. LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ...

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

    LEHR NO. 2 AND LEHR NO. 3 ADJACENT TO FURNACE ROOM; THE PIPES AT THE BOTTOM ARE PART OF THE RADIANT HEATING SYSTEM USED FOR HEATING THE FACTORY DURING COLD WEATHER. - Westmoreland Glass Company, Seventh & Kier Streets, Grapeville, Westmoreland County, PA

  4. Biogeochemistry of hydrothermally and adjacent non-altered soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized seven pedons, developed in hydrothermally and adjacent non-hydrothermally altered andesitic parent material near Reno, NV. Hydrothermally altered soils had considerably lo...

  5. 12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE ...

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

    12. LOG FOUNDATION ELEMENTS OF THE SAWMILL ADJACENT TO THE CANAL, LOOKING EAST. BARREN AREA IN FOREGROUND IS DECOMPOSING SAWDUST. DIRT PILE IN BACKGROUND IS THE EDGE OF THE SUMMIT COUNTY LANDFILL. - Snake River Ditch, Headgate on north bank of Snake River, Dillon, Summit County, CO

  6. Measurement Methods to Determine Air Leakage Between Adjacent Zones

    SciTech Connect

    Hult, Erin L.; Dickerhoff, Darryl J.; Price, Phillip N.

    2012-09-01

    Air leakage between adjacent zones of a building can lead to indoor air quality and energy efficiency concerns, however there is no existing standard for measuring inter-zonal leakage. In this study, synthesized data and field measurements are analyzed in order to explore the uncertainty associated with different methods for collecting and analyzing fan pressurization measurements to calculate interzone leakage.

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

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

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

  8. 45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, ...

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

    45. 1915 CLOTH ROOM ADJACENT TO PICKER ROOM, SECOND FLOOR, NORTH END OF MILL NO. 2, WALL ON LEFT DIVIDING CLOTH ROOM ADDED LATER (PROBABLY C. 1970s). - Prattville Manufacturing Company, Number One, 242 South Court Street, Prattville, Autauga County, AL

  9. 11. View north from the adjacent B & O railroad ...

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

    11. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

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

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

    12. View north from the adjacent B & O railroad bridge of portion of the Main truss span over the reservoir of the Augustine Paper Mills, National Register Site, including Pier No. 4. - Augustine Bridge, Brandywine River,Augustine Cutoff, Wilmington, New Castle County, DE

  11. 10. Detail and contextual view of bridge and adjacent farmstead ...

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

    10. Detail and contextual view of bridge and adjacent farmstead setting. Note laced vertical compression members, latticed portal strut, decorative strut bracing, and lightness of diagonal and lateral tension members. View to southeast through southeast portal from truss mid-span. - Red Bank Creek Bridge, Spanning Red Bank Creek at Rawson Road, Red Bluff, Tehama County, CA

  12. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  13. 47 CFR 73.810 - Third adjacent channel interference.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... RADIO BROADCAST SERVICES Low Power FM Broadcast Stations (LPFM) § 73.810 Third adjacent channel... power FM, FM translator or FM booster station to such affected station and to the Commission. (ii) A full power FM, FM translator or FM booster station shall review all complaints it receives,...

  14. 8. Exterior view, showing tank and associated piping adjacent to ...

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

    8. Exterior view, showing tank and associated piping adjacent to Test Cell 6, Systems Integration Laboratory Building (T-28), looking south. - Air Force Plant PJKS, Systems Integration Laboratory, Systems Integration Laboratory Building, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  15. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON ...

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

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA ON RIGHT, AND HOUSING AREA ON LEFT. VIEW FACING EAST/NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  16. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ...

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

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING RECREATION AREA AND ENTRY TO NEIGHBORHOOD. VIEW FACING SOUTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  17. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF ...

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

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING WESTERN SIDE OF NEIGHBORHOOD. VIEW FACING NORTHWEST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

  18. VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ...

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

    VIEW FROM ATOP ADJACENT RESIDENTIAL TOWER, SHOWING INTERSECTION OF ACACIA ROAD WITH BIRCH CIRCLE. VIEW FACING NORTHEAST - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, Intersection of Acacia Road and Brich Circle, Pearl City, Honolulu County, HI

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

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

    3. View of side of house facing north from adjacent property. Original wood siding and trim is visible. Note: later addition to rear of house is shown in right side of photograph. - 322 South Fifteenth Street (House), Louisville, Jefferson County, KY

  20. How subaerial salt extrusions influence water quality in adjacent aquifers

    NASA Astrophysics Data System (ADS)

    Mehdizadeh, Razieh; Zarei, Mehdi; Raeisi, Ezzat

    2015-12-01

    Brines supplied from salt extrusions cause significant groundwater salinization in arid and semi-arid regions where salt rock is exposed to dissolution by episodic rainfalls. Here we focus on 62 of the 122 diapirs of Hormuz salt emergent in the southern Iran. To consider managing the degradation effect that salt extrusions have on the quality of adjoining aquifers, it is first necessary to understand how they influence adjacent water resources. We evaluate here the impacts that these diapirs have on adjacent aquifers based on investigating their geomorphologies, geologies, hydrologies and hydrogeologies. The results indicate that 28/62 (45%) of our sample of salt diapirs have no significant impact on the quality of groundwater in adjoining aquifers (namely Type N), while the remaining 34/62 (55%) degrade nearby groundwater quality. We offer simple conceptual models that account for how brines flowing from each of these types of salt extrusions contaminate adjacent aquifers. We identify three main mechanisms that lead to contamination: surface impact (Type A), subsurface intrusion (Type B) and indirect infiltration (Type C). A combination of all these mechanisms degrades the water quality in nearby aquifers in 19/62 (31%) of the salt diapirs studied. Having characterized the mechanism(s) by which each diapir affects the adjacent aquifer, we suggest a few possible remediation strategies to be considered. For instance, engineering the surface runoff of diapirs Types A and C into nearby evaporation basins would improve groundwater quality.

  1. MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA ...

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

    MTR COOLING TOWER. BASIN IS ADJACENT TO PUMP HOUSE. CAMERA FACES SOUTHEAST TOWARD NORTH SIDE OF PUMP HOUSE. INL NEGATIVE NO. 2690. Unknown Photographer, 6/1951. - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

  2. 1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN ...

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

    1. VIEW FROM SOUTHWEST SHOWING SOUTH (FRONT) ELEVATION, ADJACENT LOUGHRAN BUILDING (BASSIN'S RESTAURANT) (HABS No. DC-357), 501-511 14TH STREET (THE LOCKER ROOM) HABS No. DC-356) ON CORNER, AND MUNSEY BUILDING (HABS No. DC-358) - William J. Stone Building, 1345 E Street Northwest, Washington, District of Columbia, DC

  3. 2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD ...

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

    2. VIEW FROM ROOFTOP OF BUILDING (MOTEL) ADJACENT TO TECHWOOD HOMES, LOOKING WEST. GEORGIA TECH DORMITORY BUILDING, 581-587 TECHWOOD DRIVE, IN FOREGROUND. - Techwood Homes (Public Housing), Bounded by North Avenue, Parker Street, William Street & Lovejoy Street, Atlanta, Fulton County, GA

  4. 7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL ...

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

    7. VIEW OF WATER TREATMENT PLANT, ADJACENT TO THE COAL CONVEYOR; IN THE DISTANCE IS THE FREQUENCY CHANGER HOUSE, WHICH IS ATTACHED TO SWITCH HOUSE NO. 1; LOOKING WEST. - Commonwealth Electric Company, Fisk Street Electrical Generating Station, 1111 West Cermak Avenue, Chicago, Cook County, IL

  5. Secondary orthostatic tremor in the setting of cerebellar degeneration.

    PubMed

    Sarva, Harini; Severt, William Lawrence; Jacoby, Nuri; Pullman, Seth L; Saunders-Pullman, Rachel

    2016-05-01

    Orthostatic tremor (OT) and cerebellar ataxia are uncommon and difficult to treat. We present two patients with OT and cerebellar degeneration, one of whom had spinocerebellar ataxia type 2 and a good treatment response.

  6. Intervertebral disc degeneration: evidence for two distinct phenotypes

    PubMed Central

    Adams, Michael A; Dolan, Patricia

    2012-01-01

    We review the evidence that there are two types of disc degeneration. ‘Endplate-driven’ disc degeneration involves endplate defects and inwards collapse of the annulus, has a high heritability, mostly affects discs in the upper lumbar and thoracic spine, often starts to develop before age 30 years, usually leads to moderate back pain, and is associated with compressive injuries such as a fall on the buttocks. ‘Annulus-driven’ disc degeneration involves a radial fissure and/or a disc prolapse, has a low heritability, mostly affects discs in the lower lumbar spine, develops progressively after age 30 years, usually leads to severe back pain and sciatica, and is associated with repetitive bending and lifting. The structural defects which initiate the two processes both act to decompress the disc nucleus, making it less likely that the other defect could occur subsequently, and in this sense the two disc degeneration phenotypes can be viewed as distinct. PMID:22881295

  7. Arbitrary electron acoustic waves in degenerate dense plasmas

    NASA Astrophysics Data System (ADS)

    Rahman, Ata-ur; Mushtaq, A.; Qamar, A.; Neelam, S.

    2016-12-01

    A theoretical investigation is carried out of the nonlinear dynamics of electron-acoustic waves in a collisionless and unmagnetized plasma whose constituents are non-degenerate cold electrons, ultra-relativistic degenerate electrons, and stationary ions. A dispersion relation is derived for linear EAWs. An energy integral equation involving the Sagdeev potential is derived, and basic properties of the large amplitude solitary structures are investigated in such a degenerate dense plasma. It is shown that only negative large amplitude EA solitary waves can exist in such a plasma system. The present analysis may be important to understand the collective interactions in degenerate dense plasmas, occurring in dense astrophysical environments as well as in laser-solid density plasma interaction experiments.

  8. Neuronal degeneration in subacute necrotizing encephalomyelopathy (Leigh's disease). Case report.

    PubMed

    Lindboe, C F; Lie, A K; Aase, S T; Schjetne, O B; Haave, I

    1995-01-01

    We report clinical, radiological and pathological findings in a 5-year-old girl who died of subacute necrotizing encephalomyelopathy (SNE) after 4 weeks of illness. Autopsy revealed endothelial swelling and vacuolar degeneration of the neuropil in the brain, brain stem and cerebellum. In addition, the affected areas showed degeneration of the neurons which was different from anoxic nerve cell damage both with regard to morphological picture and topographical distribution. This neuronal degeneration was probably due to the underlying metabolic defect in SNE per se and resembled in several aspects the nerve cell changes seen in the thalami and inferior olives in active Wernicke's encephalopathy. It is our opinion that more attention should be paid to the nerve cell degeneration in SNE rather than focusing on the relative preservation of these cells.

  9. Construction of nonregular pointwise degenerate delay-differential systems

    NASA Technical Reports Server (NTRS)

    Choudhury, A. K.

    1978-01-01

    Pointwise degenerate delay-differential systems (degeneracy at t = 2h) are reduced to Popov's construction under the regularity assumption. Necessary and sufficient conditions for the degeneracy are outlined.

  10. Purifying Greenberger-Horne-Zeilinger states using degenerate quantum codes

    NASA Astrophysics Data System (ADS)

    Ho, K. H.; Chau, H. F.

    2008-10-01

    Degenerate quantum codes are codes that do not reveal the complete error syndrome. Their ability to conceal the complete error syndrome makes them powerful resources in certain quantum-information processing tasks. In particular, the most error-tolerant way to purify depolarized Bell states using one-way communication known to date involves degenerate quantum codes. Here we study three closely related purification schemes for depolarized Greenberger-Horne-Zeilinger states shared among m⩾3 players by means of degenerate quantum codes and one-way classical communications. We find that our schemes tolerate more noise than all other one-way schemes known to date, further demonstrating the effectiveness of degenerate quantum codes in quantum-information processing.

  11. Degenerate higher derivative theories beyond Horndeski: evading the Ostrogradski instability

    SciTech Connect

    Langlois, David; Noui, Karim E-mail: karim.noui@lmpt.univ-tours.fr

    2016-02-01

    Theories with higher order time derivatives generically suffer from ghost-like instabilities, known as Ostrogradski instabilities. This fate can be avoided by considering ''degenerate'' Lagrangians, whose kinetic matrix cannot be inverted, thus leading to constraints between canonical variables and a reduced number of physical degrees of freedom. In this work, we derive in a systematic way the degeneracy conditions for scalar-tensor theories that depend quadratically on second order derivatives of a scalar field. We thus obtain a classification of all degenerate theories within this class of scalar-tensor theories. The quartic Horndeski Lagrangian and its extension beyond Horndeski belong to these degenerate cases. We also identify new families of scalar-tensor theories with the property that they are degenerate despite the nondegeneracy of the purely scalar part of their Lagrangian.

  12. Age-related macular degeneration: current treatment and future options.

    PubMed

    Moutray, Tanya; Chakravarthy, Usha

    2011-09-01

    Age-related macular degeneration is the leading cause of visual impairment among older adults in the developed world. Epidemiological studies have revealed a number of genetic, ocular and environmental risk factors for this condition, which can be addressed by disease reduction strategies. We discuss the various treatment options for dry and exudative age-related macular degeneration available and explain how the recommended treatment depends on the exact type, location and extent of the degeneration. Currently, vascular endothelial growth factor (VEGF) inhibition therapy is the best available treatment for exudative age-related macular degeneration but is limited by the need for repeated intravitreal injections. The current treatment regime is being refined through research on optimal treatment frequency and duration and type of anti-VEGF drug. Different modes of drug delivery are being developed and in the future other methods of VEGF inhibition may be used.

  13. [Progress on the degeneration mechanism of cave fishes' eyes].

    PubMed

    Gu, Xian; Ning, Tiao; Xiao, Heng

    2012-08-01

    Attempts to understand the degeneration of the eyes in cave fish has largely been explained by either various extents of gradual degeneration, ranging from partial to total loss, observed in various species or by acceleration of loss caused by dark environments. However, neither the theory of biological evolution developed by Charles Darwin nor the neutral theory of molecular evolution formulated by Kimura Motoo adequately explains these phenomena. Recent trends in utilizing multidisciplinary research, however, have yielded better results, helping reveal a more complex picture of the mechanisms of degeneration. Here, we summarize the current progress of the research via morphology and anatomy, development biology, animal behavior science and molecular genetics, and offer some perspectives on the ongoing research into the development and degeneration of eyes in cave fish.

  14. Drosophila melanogaster as a Model of Muscle Degeneration Disorders.

    PubMed

    Kreipke, R E; Kwon, Y V; Shcherbata, H R; Ruohola-Baker, H

    2017-01-01

    Drosophila melanogaster provides a powerful platform with which researchers can dissect complex genetic questions and biochemical pathways relevant to a vast array of human diseases and disorders. Of particular interest, much work has been done with flies to elucidate the molecular mechanisms underlying muscle degeneration diseases. The fly is particularly useful for modeling muscle degeneration disorders because there are no identified satellite muscle cells to repair adult muscle following injury. This allows for the identification of endogenous processes of muscle degeneration as discrete events, distinguishable from phenotypes due to the lack of stem cell-based regeneration. In this review, we will discuss the ways in which the fruit fly provides a powerful platform with which to study human muscle degeneration disorders.

  15. MyD88-dependent Toll-like receptor 4 signal pathway in intervertebral disc degeneration

    PubMed Central

    Qin, Chuqiang; Zhang, Bo; Zhang, Liang; Zhang, Zhi; Wang, Le; Tang, Long; Li, Shuangqing; Yang, Yixi; Yang, Fuguo; Zhang, Ping; Yang, Bo

    2016-01-01

    Lower back pain (LBP) is a common and remitting problem. One of the primary causes of LBP is thought to be degeneration of the intervertebral disc (IVD). The aim of the present study was to investigate the role of the myeloid differentiation primary-response protein 88 (MyD88)-dependent Toll-like receptor 4 (TLR4) signal pathway in the mechanism of IVD degeneration. IVD nucleus pulposus cells isolated and cultured from the lumbar vertebrae of Wistar rats were stimulated by various doses of lipopolysaccharide (LPS; 0.1, 1, 10 and 100 µg/ml) to simulate IVD degeneration. Cells were rinsed and cultured in serum-free Dulbecco's modified Eagle's medium/F12. Reverse transcription-quantitative polymerase chain reaction was used to determine the levels of TLR4, MyD88, tumor necrosis factor α (TNFα), and interleukin-1β (IL-1β) mRNA expression after 1, 3, 6, 9 and 12 h of incubation. Additionally, western blot and enzyme-linked immunosorbent assay analyses were used to determine the levels of TLR4, MyD88, TNFα, and IL-1β protein expression after 24, 48 and 72 h of incubation. The levels of TLR4, MyD88, TNFα and IL-1β mRNA all increased in the cells stimulated by 10 µg/ml LPS at 3, 6 and 9 h (all P<0.001). Furthermore, the levels of TLR4, MyD88, TNFα and IL-1β protein all increased at 24, 48 and 72 h (all P<0.001). Additionally, the mRNA and protein levels of TLR4, MyD88, TNFα and IL-1β increased significantly in the cells stimulated by 1, 10 and 100 µg/ml LPS compared with the control group, and reached a peak in the 10 µg/ml LPS group (all P<0.001). These results suggest that the MyD88-dependent TLR4 signal pathway is a target pathway in IVD degeneration. This pathway is time phase- and dose-dependent, and when activated can lead to the release of inflammatory factors that participate in IVD degeneration. PMID:27446251

  16. Block of gap junctions eliminates aberrant activity and restores light responses during retinal degeneration.

    PubMed

    Toychiev, Abduqodir H; Ivanova, Elena; Yee, Christopher W; Sagdullaev, Botir T

    2013-08-28

    Retinal degeneration leads to progressive photoreceptor cell death, resulting in vision loss. Subsequently, inner retinal neurons develop aberrant synaptic activity, compounding visual impairment. In retinal ganglion cells, light responses driven by surviving photoreceptors are obscured by elevated levels of aberrant spiking activity. Here, we demonstrate in rd10 mice that targeting disruptive neuronal circuitry with a gap junction antagonist can significantly reduce excessive spiking. This treatment increases the sensitivity of the degenerated retina to light stimuli driven by residual photoreceptors. Additionally, this enhances signal transmission from inner retinal neurons to ganglion cells, potentially allowing the retinal network to preserve the fidelity of signals either from prosthetic electronic devices, or from cells optogenetically modified to transduce light. Thus, targeting maladaptive changes to the retina allows for treatments to use existing neuronal tissue to restore light sensitivity, and to augment existing strategies to replace lost photoreceptors.

  17. Arachidonic Acid Derivatives and Their Role in Peripheral Nerve Degeneration and Regeneration

    PubMed Central

    Camara-Lemarroy, Carlos Rodrigo; Gonzalez-Moreno, Emmanuel Irineo; Guzman-de la Garza, Francisco Javier; Fernandez-Garza, Nancy Esthela

    2012-01-01

    After peripheral nerve injury, a process of axonal degradation, debris clearance, and subsequent regeneration is initiated by complex local signaling, called Wallerian degeneration (WD). This process is in part mediated by neuroglia as well as infiltrating inflammatory cells and regulated by inflammatory mediators such as cytokines, chemokines, and the activation of transcription factors also related to the inflammatory response. Part of this neuroimmune signaling is mediated by the innate immune system, including arachidonic acid (AA) derivatives such as prostaglandins and leukotrienes. The enzymes responsible for their production, cyclooxygenases and lipooxygenases, also participate in nerve degeneration and regeneration. The interactions between signals for nerve regeneration and neuroinflammation go all the way down to the molecular level. In this paper, we discuss the role that AA derivatives might play during WD and nerve regeneration, and the therapeutic possibilities that arise. PMID:22997489

  18. MAPK signaling promotes axonal degeneration by speeding the turnover of the axonal maintenance factor NMNAT2

    PubMed Central

    Walker, Lauren J; Summers, Daniel W; Sasaki, Yo; Brace, EJ; Milbrandt, Jeffrey; DiAntonio, Aaron

    2017-01-01

    Injury-induced (Wallerian) axonal degeneration is regulated via the opposing actions of pro-degenerative factors such as SARM1 and a MAPK signal and pro-survival factors, the most important of which is the NAD+ biosynthetic enzyme NMNAT2 that inhibits activation of the SARM1 pathway. Here we investigate the mechanism by which MAPK signaling facilitates axonal degeneration. We show that MAPK signaling promotes the turnover of the axonal survival factor NMNAT2 in cultured mammalian neurons as well as the Drosophila ortholog dNMNAT in motoneurons. The increased levels of NMNAT2 are required for the axonal protection caused by loss of MAPK signaling. Regulation of NMNAT2 by MAPK signaling does not require SARM1, and so cannot be downstream of SARM1. Hence, pro-degenerative MAPK signaling functions upstream of SARM1 by limiting the levels of the essential axonal survival factor NMNAT2 to promote injury-dependent SARM1 activation. These findings are consistent with a linear molecular pathway for the axonal degeneration program. DOI: http://dx.doi.org/10.7554/eLife.22540.001 PMID:28095293

  19. Aerobic Exercise Protects Retinal Function and Structure from Light-Induced Retinal Degeneration

    PubMed Central

    Lawson, Eric C.; Han, Moon K.; Sellers, Jana T.; Chrenek, Micah A.; Hanif, Adam; Gogniat, Marissa A.

    2014-01-01

    Aerobic exercise is a common intervention for rehabilitation of motor, and more recently, cognitive function (Intlekofer and Cotman, 2013; Wood et al., 2012). While the underlying mechanisms are complex, BDNF may mediate much of the beneficial effects of exercise to these neurons (Ploughman et al., 2007; Griffin et al., 2011; Real et al., 2013). We studied the effects of aerobic exercise on retinal neurons undergoing degeneration. We exercised wild-type BALB/c mice on a treadmill (10 m/min for 1 h) for 5 d/week or placed control mice on static treadmills. After 2 weeks of exercise, mice were exposed to either toxic bright light (10,000 lux) for 4 h to induce photoreceptor degeneration or maintenance dim light (25 lux). Bright light caused 75% loss of both retinal function and photoreceptor numbers. However, exercised mice exposed to bright light had 2 times greater retinal function and photoreceptor nuclei than inactive mice exposed to bright light. In addition, exercise increased retinal BDNF protein levels by 20% compared with inactive mice. Systemic injections of a BDNF tropomyosin-receptor-kinase (TrkB) receptor antagonist reduced retinal function and photoreceptor nuclei counts in exercised mice to inactive levels, effectively blocking the protective effects seen with aerobic exercise. The data suggest that aerobic exercise is neuroprotective for retinal degeneration and that this effect is mediated by BDNF signaling. PMID:24523530

  20. Influence of anti-VEGF about cardiovascular biomarkers in age related macular degeneration.

    PubMed

    Manresa, N; Mulero, J; Losada, M; Zafrilla, P

    2015-02-01

    Systemic VEGF inhibition disrupts endothelial homeostasis and accelerates the atherogenesis, suggesting that these events contribute to the clinical cardiovascular adverse events of VEGF-inhibiting therapies. The objective of the current study was to analyze the effect of anti-VEGF therapy on cardiovascular risk factors in patients with exudative age related macular degeneration. A total of 73 patients with exudative age related macular degeneration (without previous anti-VEGF therapy) were treated with two anti-VEGF: Ranibizumab and Pegaptanib sodium. The follow up was 6 months. The following parameters were determined before and after treatment: homocysteine, lipids (total cholesterol, triglycerides, HDL-c, LDL-c), C-Reactive Protein and fibrinogen. There were not statistically significant differences in parameters studied before and after treatment with both Pegaptanib sodium and Ranibizumab, except C-Reactive Protein. Of all patients analyzed, only 3 of them have initially C-Reactive Protein levels above normal levels and after antiangiogenic therapy, there was a significant increase in C-Reactive Protein. We have not found results in our study who to suspect that treatment with anti-VEGF in the patients with exudative age related macular degeneration increases cardiovascular risk predictors. However, after therapy was increased the CRP and fibrinogen may mean that anti-VEGF contribute an alteration of endothelial homeostasis in exudative AMD.

  1. The Effects of Platelet-Rich Plasma on Halting the Progression in Porcine Intervertebral Disc Degeneration.

    PubMed

    Cho, Hongsik; Holt, David C; Smith, Richard; Kim, Song-Ja; Gardocki, Raymond J; Hasty, Karen A

    2016-02-01

    Disc degeneration and the subsequent herniation and/or rupture of the intervertebral disc (IVD) are due to a failure of the extracellular matrix of the annulus to contain the contents of the nucleus. This results from inadequate maintenance of the matrix components as well as the proteolytic activity of matrix metalloproteinases (MMPs) that degrade matrix molecules. Arresting progression of disc degeneration in the annulus holds greater clinical potential at this point than prevention of its onset in the nucleus. Therefore, in this study, we have therapeutic aims that would decrease levels of the cytokines and growth factors that indirectly lead to disc degeneration via stimulating MMP and increase levels of several beneficial growth factors, such as transforming growth factor-β, with the addition of platelet-rich plasma (PRP) that would stimulate cell growth and matrix synthesis. For this study, we attempted to address these imbalances of metabolism by using tumor necrosis factor-α treated annulus fibrosus cells isolated from porcine IVD tissue and incubating the cells in a growth factor rich environment with PRP. These results indicate that the PRP in vitro increased the production of the major matrix components (type II collagen and aggrecan) and decreased the inhibitory collagenase MMP-1. This application will address a therapeutic approach for intervening early in the degenerative process.

  2. Aerobic exercise protects retinal function and structure from light-induced retinal degeneration.

    PubMed

    Lawson, Eric C; Han, Moon K; Sellers, Jana T; Chrenek, Micah A; Hanif, Adam; Gogniat, Marissa A; Boatright, Jeffrey H; Pardue, Machelle T

    2014-02-12

    Aerobic exercise is a common intervention for rehabilitation of motor, and more recently, cognitive function (Intlekofer and Cotman, 2013; Wood et al., 2012). While the underlying mechanisms are complex, BDNF may mediate much of the beneficial effects of exercise to these neurons (Ploughman et al., 2007; Griffin et al., 2011; Real et al., 2013). We studied the effects of aerobic exercise on retinal neurons undergoing degeneration. We exercised wild-type BALB/c mice on a treadmill (10 m/min for 1 h) for 5 d/week or placed control mice on static treadmills. After 2 weeks of exercise, mice were exposed to either toxic bright light (10,000 lux) for 4 h to induce photoreceptor degeneration or maintenance dim light (25 lux). Bright light caused 75% loss of both retinal function and photoreceptor numbers. However, exercised mice exposed to bright light had 2 times greater retinal function and photoreceptor nuclei than inactive mice exposed to bright light. In addition, exercise increased retinal BDNF protein levels by 20% compared with inactive mice. Systemic injections of a BDNF tropomyosin-receptor-kinase (TrkB) receptor antagonist reduced retinal function and photoreceptor nuclei counts in exercised mice to inactive levels, effectively blocking the protective effects seen with aerobic exercise. The data suggest that aerobic exercise is neuroprotective for retinal degeneration and that this effect is mediated by BDNF signaling.

  3. SINGLE-DEGENERATE TYPE Ia SUPERNOVAE ARE PREFERENTIALLY OVERLUMINOUS

    SciTech Connect

    Fisher, Robert; Jumper, Kevin

    2015-06-01

    Recent observational and theoretical progress has favored merging and helium-accreting sub-Chandrasekhar mass white dwarfs (WDs) in the double-degenerate and the double-detonation channels, respectively, as the most promising progenitors of normal Type Ia supernovae (SNe Ia). Thus the fate of rapidly accreting Chandrasekhar mass WDs in the single-degenerate channel remains more mysterious then ever. In this paper, we clarify the nature of ignition in Chandrasekhar-mass single-degenerate SNe Ia by analytically deriving the existence of a characteristic length scale which establishes a transition from central ignitions to buoyancy-driven ignitions. Using this criterion, combined with data from three-dimensional simulations of convection and ignition, we demonstrate that the overwhelming majority of ignition events within Chandrasekhar-mass WDs in the single-degenerate channel are buoyancy-driven, and consequently lack a vigorous deflagration phase. We thus infer that single-degenerate SNe Ia are generally expected to lead to overluminous 1991T-like SNe Ia events. We establish that the rates predicted from both the population of supersoft X-ray sources (SSSs) and binary population synthesis models of the single-degenerate channel are broadly consistent with the observed rates of overluminous SNe Ia, and suggest that the population of SSSs are the dominant stellar progenitors of SNe 1991T-like events. We further demonstrate that the single-degenerate channel contribution to the normal and failed 2002cx-like rates is not likely to exceed 1% of the total SNe Ia rate. We conclude with a range of observational tests of overluminous SNe Ia which will either support or strongly constrain the single-degenerate scenario.

  4. Rehabilitation Approaches in Macular Degeneration Patients

    PubMed Central

    Maniglia, Marcello; Cottereau, Benoit R.; Soler, Vincent; Trotter, Yves

    2016-01-01

    Age related macular degeneration (AMD) is a visual disease that affects elderly population. It entails a progressive loss of central vision whose consequences are dramatic for the patient’s quality of life. Current rehabilitation programs are restricted to technical aids based on visual devices. They only temporarily improve specific visual functions such as reading skills. Considering the rapid increase of the aging population worldwide, it is crucial to intensify clinical research on AMD in order to develop simple and efficient methods that improve the patient’s visual performances in many different contexts. One very promising approach to face this challenge is based on perceptual learning (PL). Through intensive practice, PL can induce neural plasticity in sensory cortices and result in long-lasting enhancements for various perceptual tasks in both normal and visually impaired populations. A growing number of studies showed how appropriate PL protocols improve visual functions in visual disorders, namely amblyopia, presbyopia or myopia. In order to successfully apply these approaches to more severe conditions such as AMD, numerous challenges have to be overcome. Indeed, the overall elderly age of patients and the reduced cortical surface that is devoted to peripheral vision potentially limit neural plasticity in this population. In addition, ocular fixation becomes much less stable because patients have to rely on peripheral fixation spots outside the scotoma whose size keeps on evolving. The aim of this review article is to discuss the recent literature on this topic and to offer a unified approach for developing new rehabilitation programs of AMD using PL. We argue that with an appropriate experimental and training protocol that is adapted to each patient needs, PL can offer fascinating opportunities for the development of simple, non-expensive rehabilitation approaches a large spectrum of visual functions in AMD patients. PMID:28082876

  5. Perceptual learning in patients with macular degeneration.

    PubMed

    Plank, Tina; Rosengarth, Katharina; Schmalhofer, Carolin; Goldhacker, Markus; Brandl-Rühle, Sabine; Greenlee, Mark W

    2014-01-01

    Patients with age-related macular degeneration (AMD) or hereditary macular dystrophies (JMD) rely on an efficient use of their peripheral visual field. We trained eight AMD and five JMD patients to perform a texture-discrimination task (TDT) at their preferred retinal locus (PRL) used for fixation. Six training sessions of approximately one hour duration were conducted over a period of approximately 3 weeks. Before, during and after training twelve patients and twelve age-matched controls (the data from two controls had to be discarded later) took part in three functional magnetic resonance imaging (fMRI) sessions to assess training-related changes in the BOLD response in early visual cortex. Patients benefited from the training measurements as indexed by significant decrease (p = 0.001) in the stimulus onset asynchrony (SOA) between the presentation of the texture target on background and the visual mask, and in a significant location specific effect of the PRL with respect to hit rate (p = 0.014). The following trends were observed: (i) improvement in Vernier acuity for an eccentric line-bisection task; (ii) positive correlation between the development of BOLD signals in early visual cortex and initial fixation stability (r = 0.531); (iii) positive correlation between the increase in task performance and initial fixation stability (r = 0.730). The first two trends were non-significant, whereas the third trend was significant at p = 0.014, Bonferroni corrected. Consequently, our exploratory study suggests that training on the TDT can enhance eccentric vision in patients with central vision loss. This enhancement is accompanied by a modest alteration in the BOLD response in early visual cortex.

  6. Rehabilitation Approaches in Macular Degeneration Patients.

    PubMed

    Maniglia, Marcello; Cottereau, Benoit R; Soler, Vincent; Trotter, Yves

    2016-01-01

    Age related macular degeneration (AMD) is a visual disease that affects elderly population. It entails a progressive loss of central vision whose consequences are dramatic for the patient's quality of life. Current rehabilitation programs are restricted to technical aids based on visual devices. They only temporarily improve specific visual functions such as reading skills. Considering the rapid increase of the aging population worldwide, it is crucial to intensify clinical research on AMD in order to develop simple and efficient methods that improve the patient's visual performances in many different contexts. One very promising approach to face this challenge is based on perceptual learning (PL). Through intensive practice, PL can induce neural plasticity in sensory cortices and result in long-lasting enhancements for various perceptual tasks in both normal and visually impaired populations. A growing number of studies showed how appropriate PL protocols improve visual functions in visual disorders, namely amblyopia, presbyopia or myopia. In order to successfully apply these approaches to more severe conditions such as AMD, numerous challenges have to be overcome. Indeed, the overall elderly age of patients and the reduced cortical surface that is devoted to peripheral vision potentially limit neural plasticity in this population. In addition, ocular fixation becomes much less stable because patients have to rely on peripheral fixation spots outside the scotoma whose size keeps on evolving. The aim of this review article is to discuss the recent literature on this topic and to offer a unified approach for developing new rehabilitation programs of AMD using PL. We argue that with an appropriate experimental and training protocol that is adapted to each patient needs, PL can offer fascinating opportunities for the development of simple, non-expensive rehabilitation approaches a large spectrum of visual functions in AMD patients.

  7. Treatment of macular degeneration, according to Bangerter.

    PubMed

    Teichmann, K D

    1997-10-30

    Age-related macular degeneration (AMD) is a common cause of visual loss among elderly patients. Although some risk factors have been determined, the ultimate cause of the disease is not known. For a long time, therapeutic nihilism has been the rule among ophthalmologists confronted with such patients. Bangerter has not shared this attitude, especially since the time that he incidentally discovered, more than 40 years ago, the beneficial effects of radiotherapy, in discouraging the growth of new vessels at the posterior pole of the eye. A variety of approaches are combined and used by Bangerter in the treatment of the different types of AMD, including retrobulbar injections of either vasodilating medications (in the dry - or atrophic - type) or corticosteroids (in the wet - or exudative - type), general medical measures aimed at improving metabolic and vascular functions such as supplementation with trace elements, antioxidants, and vitamins; ozone therapy; advice to increase physical fitness, improve nutrition, and abstain from smoking; and protection from excessive light exposure. Being convinced of the usefulness of his type of combination treatment, he has always rejected undertaking controlled clinical trials, of only single aspects of the therapy, as unethical and invalid. For this reason, scientific journals have not proven cooperative in several attempts at publishing his results, as collected in retrospective surveys. Recently, however, some of the several approaches combined by Bangerter in treating AMD have been pronounced effective by other investigators. We present here an overview of his treatment approaches, as few people are aware of them, to clear up misconceptions and to set records straight.

  8. Mortality of passerines adjacent to a North Carolina corn field treated with granular carbofuran.

    USGS Publications Warehouse

    Augspurger, Tom; Smith, Milton R.; Meteyer, Carol U.; Converse, Kathryn A.

    1996-01-01

    Red-winged blackbirds (Agelaius phoeniceus) were collected during an epizootic in southeastern North Carolina (USA). Activity of brain cholinesterase (ChE) was inhibited by 14 to 48% in three of five specimens, and returned to normal levels after incubation. Gastrointestinal tracts were analyzed for 30 anti-ChE agents. Carbofuran, the only compound detected, was present in all specimens at levels from 5.44 to 72.7 μg/g wet weight. Application of granular carbofuran in an adjacent corn field, results of necropsy examinations, and chemical analyses are consistent with a diagnosis of carbofuran poisoning in these specimens.

  9. Prolonged Prevention of Retinal Degeneration with Retinylamine Loaded Nanoparticles

    PubMed Central

    Puntel, Anthony; Maeda, Akiko; Golczak, Marcin; Gao, Song-Qi; Yu, Guanping; Palczewski, Krzysztof; Lu, Zheng-Rong

    2015-01-01

    Retinal degeneration impairs the vision of millions in all age groups worldwide. Increasing evidence suggests that the etiology of many retinal degenerative diseases is associated with impairment in biochemical reactions involved in the visual cycle, a metabolic pathway responsible for regeneration of the visual chromophore (11-cis-retinal). Inefficient clearance of toxic retinoid metabolites, especially all-trans-retinal, is considered responsible for photoreceptor cytotoxicity. Primary amines, including retinylamine, are effective in lowing the concentration of all-trans-retinal within the retina and thus prevent retina degeneration in mouse models of human retinopathies. Here we achieved prolonged prevention of retinal degeneration by controlled delivery of retinylamine to the eye from polylactic acid nanoparticles in Abca4−/−Rdh8−/− (DKO) mice, an animal model of Stargardt disease/age-related macular degeneration. Subcutaneous administration of the nanoparticles containing retinylamine provided a constant supply of the drug to the eye for about a week and resulted in effective prolonged prevention of light-induced retinal degeneration in DKO mice. Retinylamine nanoparticles hold promise for prolonged prophylactic treatment of human retinal degenerative diseases, including Stargardt disease and age-related macular degeneration. PMID:25617130

  10. Axons degenerate in the absence of mitochondria in C. elegans.

    PubMed

    Rawson, Randi L; Yam, Lung; Weimer, Robby M; Bend, Eric G; Hartwieg, Erika; Horvitz, H Robert; Clark, Scott G; Jorgensen, Erik M

    2014-03-31

    Many neurodegenerative disorders are associated with mitochondrial defects [1-3]. Mitochondria can play an active role in degeneration by releasing reactive oxygen species and apoptotic factors [4-7]. Alternatively, mitochondria can protect axons from stress and insults, for example by buffering calcium [8]. Recent studies manipulating mitochondria lend support to both of these models [9-13]. Here, we identify a C. elegans mutant, ric-7, in which mitochondria are unable to exit the neuron cell bodies, similar to the kinesin-1/unc-116 mutant. When axons lacking mitochondria are cut with a laser, they rapidly degenerate. Some neurons even spontaneously degenerate in ric-7 mutants. Degeneration can be suppressed by forcing mitochondria into the axons of the mutants. The protective effect of mitochondria is also observed in the wild-type: a majority of axon fragments containing a mitochondrion survive axotomy, whereas those lacking mitochondria degenerate. Thus, mitochondria are not required for axon degeneration and serve a protective role in C. elegans axons.

  11. Axonal Degeneration Is Mediated by the Mitochondrial Permeability Transition Pore

    PubMed Central

    Barrientos, Sebastian A.; Martinez, Nicolas W.; Yoo, Soonmoon; Jara, Juan S.; Zamorano, Sebastian; Hetz, Claudio; Twiss, Jeffery L.; Alvarez, Jaime; Court, Felipe A.

    2011-01-01

    Axonal degeneration is an active process that has been associated with neurodegenerative conditions triggered by mechanical, metabolic, infectious, toxic, hereditary and inflammatory stimuli. This degenerative process can cause permanent loss of function, so it represents a focus for neuroprotective strategies. Several signaling pathways are implicated in axonal degeneration, but identification of an integrative mechanism for this self-destructive process has remained elusive. Here, we show that rapid axonal degeneration triggered by distinct mechanical and toxic insults is dependent on the activation of the mitochondrial permeability transition pore (mPTP). Both pharmacological and genetic targeting of cyclophilin D, a functional component of the mPTP, protects severed axons and vincristine-treated neurons from axonal degeneration in ex vivo and in vitro mouse and rat model systems. These effects were observed in axons from both the peripheral and central nervous system. Our results suggest that the mPTP is a key effector of axonal degeneration, upon which several independent signaling pathways converge. Since axonal and synapse degeneration are increasingly considered early pathological events in neurodegeneration, our work identifies a potential target for therapeutic intervention in a wide variety of conditions that lead to loss of axons and subsequent functional impairment. PMID:21248121

  12. Development of Animal Models of Local Retinal Degeneration

    PubMed Central

    Lorach, Henri; Kung, Jennifer; Beier, Corinne; Mandel, Yossi; Dalal, Roopa; Huie, Philip; Wang, Jenny; Lee, Seungjun; Sher, Alexander; Jones, Bryan William; Palanker, Daniel

    2015-01-01

    Purpose Development of nongenetic animal models of local retinal degeneration is essential for studies of retinal pathologies, such as chronic retinal detachment or age-related macular degeneration. We present two different methods to induce a highly localized retinal degeneration with precise onset time, that can be applied to a broad range of species in laboratory use. Methods A 30-μm thin polymer sheet was implanted subretinally in wild-type (WT) rats. The effects of chronic retinal separation from the RPE were studied using histology and immunohistochemistry. Another approach is applicable to species with avascular retina, such as rabbits, where the photoreceptors and RPE were thermally ablated over large areas, using a high power scanning laser. Results Photoreceptors above the subretinal implant in rats degenerated over time, with 80% of the outer nuclear layer disappearing within a month, and the rest by 3 months. Similar loss was obtained by selective photocoagulation with a scanning laser. Cells in the inner nuclear layer and ganglion cell layer were preserved in both cases. However, there were signs of rewiring and decrease in the size of the bipolar cell terminals in the damaged areas. Conclusions Both methods induce highly reproducible degeneration of photoreceptors over a defined area, with complete preservation of the inner retinal neurons during the 3-month follow-up. They provide a reliable platform for studies of local retinal degeneration and development of therapeutic strategies in a wide variety of species. PMID:26207299

  13. Spatially coordinated kinase signaling regulates local axon degeneration.

    PubMed

    Chen, Mark; Maloney, Janice A; Kallop, Dara Y; Atwal, Jasvinder K; Tam, Stephen J; Baer, Kristin; Kissel, Holger; Kaminker, Joshua S; Lewcock, Joseph W; Weimer, Robby M; Watts, Ryan J

    2012-09-26

    In addition to being a hallmark of neurodegenerative disease, axon degeneration is used during development of the nervous system to prune unwanted connections. In development, axon degeneration is tightly regulated both temporally and spatially. Here, we provide evidence that degeneration cues are transduced through various kinase pathways functioning in spatially distinct compartments to regulate axon degeneration. Intriguingly, glycogen synthase kinase-3 (GSK3) acts centrally, likely modulating gene expression in the cell body to regulate distally restricted axon degeneration. Through a combination of genetic and pharmacological manipulations, including the generation of an analog-sensitive kinase allele mutant mouse for GSK3β, we show that the β isoform of GSK3, not the α isoform, is essential for developmental axon pruning in vitro and in vivo. Additionally, we identify the dleu2/mir15a/16-1 cluster, previously characterized as a regulator of B-cell proliferation, and the transcription factor tbx6, as likely downstream effectors of GSK3β in axon degeneration.

  14. Age-related macular degeneration: beyond anti-angiogenesis.

    PubMed

    Kent, David L

    2014-01-06

    Recently, anti-vascular endothelial growth factor therapies for neovascular age-related macular degeneration have been developed. These agents, originally developed for their anti-angiogenic mechanism of action, probably also work through an anti-permeability effect in preventing or reducing the amount of leakage from submacular neovascular tissue. Other treatment modalities include laser photocoagulation, photodynamic therapy with verteporfin, and submacular surgery. In reality, these latter treatments can be similarly categorized as anti-angiogenic because their sole aim is destroying or removing choroidal neovascularization (CNV). At the cellular level, CNV resembles stereotypical tissue repair that consists of several matricellular components in addition to neovascularization. In the retina, the clinical term CNV is a misnomer since the term may more appropriately be referred to as aberrant submacular repair. Furthermore, CNV raises a therapeutic conundrum: To complete or correct any reparative process in the body, angiogenesis becomes an essential component. Anti-angiogenic therapy, in all its guises, arrests repair and causes the hypoxic environment to persist, thus fueling pro-angiogenesis and further development of CNV as a component of aberrant repair. However, we realize that anti-vascular endothelial growth factor therapy preserves vision in patients with age-related macular degeneration, albeit temporarily and therefore, repeated treatment is needed. More importantly, however, anti-angiogenic therapy demonstrates that we can at the very least tolerate neovascular tissue beneath the macula and preserve vision in contrast to our historical approach of total vascular destruction. In this clinical scenario, it may be possible to look beyond anti-angiogenesis if our goal is facilitating submacular repair without destroying the neurosensory retina. Thus, in this situation of neovascular tolerance, it may be timely to consider treatments that facilitate

  15. Effects of Tobacco Smoking on the Degeneration of the Intervertebral Disc: A Finite Element Study

    PubMed Central

    Elmasry, Shady; Asfour, Shihab; de Rivero Vaccari, Juan Pablo; Travascio, Francesco

    2015-01-01

    Tobacco smoking is associated with numerous pathological conditions. Compelling experimental evidence associates smoking to the degeneration of the intervertebral disc (IVD). In particular, it has been shown that nicotine down-regulates both the proliferation rate and glycosaminoglycan (GAG) biosynthesis of disc cells. Moreover, tobacco smoking causes the constriction of the vascular network surrounding the IVD, thus reducing the exchange of nutrients and anabolic agents from the blood vessels to the disc. It has been hypothesized that both nicotine presence in the IVD and the reduced solute exchange are responsible for the degeneration of the disc due to tobacco smoking, but their effects on tissue homeostasis have never been quantified. In this study, a previously presented computational model describing the homeostasis of the IVD was deployed to investigate the effects of impaired solute supply and nicotine-mediated down-regulation of cell proliferation and biosynthetic activity on the health of the disc. We found that the nicotine-mediated down-regulation of cell anabolism mostly affected the GAG concentration at the cartilage endplate, reducing it up to 65% of the value attained in normal physiological conditions. In contrast, the reduction of solutes exchange between blood vessels and disc tissue mostly affected the nucleus pulposus, whose cell density and GAG levels were reduced up to 50% of their normal physiological levels. The effectiveness of quitting smoking on the regeneration of a degenerated IVD was also investigated, and showed to have limited benefit on the health of the disc. A cell-based therapy in conjunction with smoke cessation provided significant improvements in disc health, suggesting that, besides quitting smoking, additional treatments should be implemented in the attempt to recover the health of an IVD degenerated by tobacco smoking. PMID:26301590

  16. Effects of degeneration on the compressive and tensile properties of human meniscus.

    PubMed

    Fischenich, Kristine M; Lewis, Jackson; Kindsfater, Kirk A; Bailey, Travis S; Haut Donahue, Tammy L

    2015-06-01

    Healthy menisci function within the joint to prevent the underlying articular cartilage from excessive loads. Understanding how mechanical properties of menisci change with degeneration can drive future therapeutic studies to prevent this degeneration. Thus, the goal of this study was to characterize both compressive and tensile moduli of human menisci with varying degrees of gross damage due to osteoarthritis (OA). Twenty four paired menisci were collected from total knee joint replacement patients and the menisci were graded on a scale from 0-4 according to level of gross meniscal degeneration with 0=normal and 4=full tissue maceration. Each meniscus was then sectioned into anterior and posterior regions and subjected to indentation relaxation tests. Samples were sliced into 1mm thick strips, made into dumbbells using a custom punch, and pulled to failure. Significant decreases in instantaneous compressive modulus were seen in the lateral posterior region between grades 0 and 1 (36% decrease) and in the medial anterior regions between grades 1 and 2 (67% decrease) and 1 and 3 (72% decrease). Changes in equilibrium modulus where seen in the lateral anterior region between grades 1 and 2 (35% decrease), lateral posterior region between grades 0-2 (41% decrease), and medial anterior regions between grades 1 and 2 (59% decrease), 1 and 3 (67% decrease), 2 and 4 (54% decrease), and 3 and 4 (42% decrease). No significant changes were observed in tensile modulus across all regions and degenerative grades. The results of this study demonstrate the compressive moduli are affected even in early stages of gross degeneration, and continue to decrease with increased deterioration. However, osteoarthritic menisci retain a tensile modulus similar to that of previously reported healthy menisci. This study highlights progressive changes in meniscal mechanical compressive integrity as level of gross tissue degradation increases, and thus, early interventions should focus on

  17. Occupational attainment influences survival in autopsy-confirmed frontotemporal degeneration

    PubMed Central

    Zee, Jarcy; Xie, Sharon X.; McMillan, Corey T.; Rascovsky, Katya; Irwin, David J.; Kolanowski, Ann; Grossman, Murray

    2015-01-01

    Objective: To examine the influence of occupational attainment and education on survival in autopsy-confirmed cases of frontotemporal lobar degeneration (FTLD) and Alzheimer disease (AD). Methods: We performed a retrospective chart review of 83 demographically matched, autopsy-confirmed FTLD (n = 34) and AD (n = 49) cases. Each patient's primary occupation was classified and ranked. Level of education was recorded in years. Survival was defined as time from symptom onset until death. Linear regression was used to test for associations among occupational attainment, education, and patient survival. Results: Median survival was 81 months for FTLD and 95 months for AD. Years of education and occupational attainment were similar for both groups. We found that higher occupational attainment was associated with longer survival in FTLD but not AD. Conclusions: Our findings suggest that higher occupational attainment is associated with longer survival in autopsy-confirmed FTLD. The identification of protective factors associated with FTLD survival has important implications for estimates of prognosis and longitudinal studies such as treatment trials. PMID:25904687

  18. Biomarkers in Frontotemporal Lobar Degenerations – Progress and Challenges

    PubMed Central

    Hu, William T.; Trojanowski, John Q.; Shaw, Leslie M.

    2011-01-01

    Neuronal and glial changes associated with tau, TAR DNA binding protein of ~43 kD (TDP-43), and fused in sarcoma (FUS) together constitute the pathologic spectrum of frontotemporal lobar degeneration (FTLD). Most patients with FTLD present with prominent behavior or language changes, sometimes accompanied by extrapyramidal symptoms or motor neuron disease. Identification of FTLD patients with mutations in genes for tau, TDP-43, and FUS lends strong support for their pathogenic roles in FTLD, and elucidation of their dysfunction will pave the way for development of substrate specific therapy. However, there remains no reliable biomarker for early detection of FTLD or prediction of underlying FTLD pathologic change. Clinical syndromes usually reflects the earliest affected brain regions where atrophy can be visualized on structural MRI, but neither clinical nor structural imaging-based biomarkers has been accurately correlated with underlying pathology on the individual patient level. Biochemical markers in the cerebrospinal fluid (CSF) have also been investigated in FTLD and related disorders, including amyotrophic lateral sclerosis (ALS) and progressive supranuclear palsy (PSP). However, their accuracy and pathologic significance need to be confirmed in future multi-center studies. Here we review the progress made in FTLD biomarkers, including clinical phenotype/feature characterization, neuropsychological analysis, CSF and plasma analytes, and patterns of brain atrophy and network dysfunction detectable on brain imaging. Given the pathologic overlap of FTLD with ALS and PSP, collaboration with specialists in those fields will be essential in the translation of promising FTLD biomarkers into clinical practice. PMID:21554923

  19. Is Preventative Long-Segment Surgery for Multi-Level Spondylolysis Necessary? A Finite Element Analysis Study

    PubMed Central

    Zhong, Dongyan; Xu, Hao; Wang, Lan; Yu, Jia; Luo, Zongping

    2016-01-01

    Objective For multi-level spondylolysis patients, surgeons commonly choose to fix all the segments with pars interarticularis defect even those without slippage and not responsible for clinical symptoms. In this study, we tried to study the necessity of the preventative long-segment surgery for the defected segment without slippage in treatment of multi-level spondylolysis patients from a biomechanical perspective. Method We established a bi-level spondylolysis model with pars defects at L4 and L5 segments, and simulated posterior lumbar interbody fusion (PLIF) and pedicle screw fixation at L5-S1 level. Then we compared the biomechanical changes at L4 segment before and after surgery in neutral, flexion, extension, lateral bending and axial rotation position. Results The stress on L4 pars interarticularis was very similar before and after surgery, and reached the highest in axial rotation. The L3-L4 intradiscal pressure was almost the same, while L4-L5 intradiscal pressure changed a little in lateral bending (increase from 1.993 to 2.160 MPa) and axial rotation (decrease from 1.639 to 1.307 MPa) after surgery. The PLIF surgery caused a little increase of range of motion at adjacent L4-L5 and L3-L4 levels, but the change is very tiny (1 degree). Conclusion The PLIF surgery will not cause significant biomechanical change at adjacent segment with pars defect in multi-level spondylolysis. On the contrary, excessive long-segment surgery will damage surrounding soft tissues which are important for maintaining the stability of spine. So a preventative long-segment surgery is not necessary for multi-level spondylolysis as long as there are no soft tissue degeneration signs at adjacent level. PMID:26918333

  20. Perfluoroalkyl substances in Daling River adjacent to fluorine industrial parks: implication from industrial emission.

    PubMed

    Meng, Jing; Wang, Tieyu; Wang, Pei; Zhu, Zhaoyun; Li, Qifeng; Lu, Yonglong

    2015-01-01

    The pollution level and source of perfluoroalkyl substances (PFASs) in mainstream and tributary of Daling River in northeast China were investigated in present study. Concentrations of PFASs in surface water and sediment ranged from 4.6 to 3,410 ng/L and from 0.08 to 2.6 ng/g dry weight, respectively. The lowest levels of PFASs were found in vicinity of a drinking water source located in upstream of Daling River. Xihe tributary, which is adjacent to two local fluorine industrial parks, contained the highest level of PFASs. Short-chain PFASs, including perfluorobutanoic acid and perfluorobutane sulfonate, were of higher levels due to their emerging as alternative products for perfluorooctane sulfonate. High level of perfluorooctanoic acid was also found in Daling River. Based on these results, it can be concluded that the relatively severe pollutions of Xihe tributary were caused by long-term development of the two local fluorine industry parks.

  1. Bacterial community composition in Brazilian Anthrosols and adjacent soils characterized using culturing and molecular identification.

    PubMed

    O'Neill, B; Grossman, J; Tsai, M T; Gomes, J E; Lehmann, J; Peterson, J; Neves, E; Thies, J E

    2009-07-01

    Microbial community composition was examined in two soil types, Anthrosols and adjacent soils, sampled from three locations in the Brazilian Amazon. The Anthrosols, also known as Amazonian dark earths, are highly fertile soils that are a legacy of pre-Columbian settlement. Both Anthrosols and adjacent soils are derived from the same parent material and subject to the same environmental conditions, including rainfall and temperature; however, the Anthrosols contain high levels of charcoal-like black carbon from which they derive their dark color. The Anthrosols typically have higher cation exchange capacity, higher pH, and higher phosphorus and calcium contents. We used culture media prepared from soil extracts to isolate bacteria unique to the two soil types and then sequenced their 16S rRNA genes to determine their phylogenetic placement. Higher numbers of culturable bacteria, by over two orders of magnitude at the deepest sampling depths, were counted in the Anthrosols. Sequences of bacteria isolated on soil extract media yielded five possible new bacterial families. Also, a higher number of families in the bacteria were represented by isolates from the deeper soil depths in the Anthrosols. Higher bacterial populations and a greater diversity of isolates were found in all of the Anthrosols, to a depth of up to 1 m, compared to adjacent soils located within 50-500 m of their associated Anthrosols. Compared to standard culture media, soil extract media revealed diverse soil microbial populations adapted to the unique biochemistry and physiological ecology of these Anthrosols.

  2. Matrix intensification alters avian functional group composition in adjacent rainforest fragments.

    PubMed

    Deikumah, Justus P; McAlpine, Clive A; Maron, Martine

    2013-01-01

    Conversion of farmland land-use matrices to surface mining is an increasing threat to the habitat quality of forest remnants and their constituent biota, with consequences for ecosystem functionality. We evaluated the effects of matrix type on bird community composition and the abundance and evenness within avian functional groups in south-west Ghana. We hypothesized that surface mining near remnants may result in a shift in functional composition of avifaunal communities, potentially disrupting ecological processes within tropical forest ecosystems. Matrix intensification and proximity to the remnant edge strongly influenced the abundance of members of several functional guilds. Obligate frugivores, strict terrestrial insectivores, lower and upper strata birds, and insect gleaners were most negatively affected by adjacent mining matrices, suggesting certain ecosystem processes such as seed dispersal may be disrupted by landscape change in this region. Evenness of these functional guilds was also lower in remnants adjacent to surface mining, regardless of the distance from remnant edge, with the exception of strict terrestrial insectivores. These shifts suggest matrix intensification can influence avian functional group composition and related ecosystem-level processes in adjacent forest remnants. The management of matrix habitat quality near and within mine concessions is important for improving efforts to preserveavian biodiversity in landscapes undergoing intensification such as through increased surface mining.

  3. Early Growth Response1and Fatty Acid Synthase Expression is Altered in Tumor Adjacent Prostate Tissue and Indicates Field Cancerization

    PubMed Central

    Jones, Anna C.; Trujillo, Kristina A.; Phillips, Genevieve K.; Fleet, Trisha M.; Murton, Jaclyn K.; Severns, Virginia; Shah, Satyan K.; Davis, Michael S.; Smith, Anthony Y.; Griffith, Jeffrey K.; Fischer, Edgar G.; Bisoffi, Marco

    2011-01-01

    BACKGROUND Field cancerization denotes the occurrence of molecular alterations in histologically normal tissues adjacent to tumors. In prostate cancer, identification of field cancerization has several potential clinical applications. However, prostate field cancerization remains ill defined. Our previous work has shown up-regulated mRNA of the transcription factor early growth response 1 (EGR-1) and the lipogenic enzyme fatty acid synthase (FAS) in tissues adjacent to prostate cancer. METHODS Immunofluorescence data were analyzed quantitatively by spectral imaging and linear unmixing to determine the protein expression levels of EGR-1 and FAS in human cancerous, histologically normal adjacent, and disease-free prostate tissues. RESULTS EGR-1 expression was elevated in both structurally intact tumor adjacent (1.6× on average) and in tumor (3.0× on average) tissues compared to disease-free tissues. In addition, the ratio of cytoplasmic versus nuclear EGR-1 expression was elevated in both tumor adjacent and tumor tissues. Similarly, FAS expression was elevated in both tumor adjacent (2.7× on average) and in tumor (2.5× on average) compared to disease-free tissues. CONCLUSIONS EGR-1 and FAS expression is similarly deregulated in tumor and structurally intact adjacent prostate tissues and defines field cancerization. In cases with high suspicion of prostate cancer but negative biopsy, identification of field cancerization could help clinicians target areas for repeat biopsy. Field cancerization at surgical margins on prostatectomy specimen should also be looked at as a predictor of cancer recurrence. EGR-1 and FAS could also serve as molecular targets for chemoprevention. PMID:22127986

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

    PubMed

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

    2012-03-01

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

  5. On the Circulation Manifold for Two Adjacent Lifting Sections

    NASA Technical Reports Server (NTRS)

    Zannetti, Luca; Iollo, Angelo

    1998-01-01

    The circulation functional relative to two adjacent lifting sections is studied for two cases. In the first case we consider two adjacent circles. The circulation is computed as a function of the displacement of the secondary circle along the axis joining the two centers and of the angle of attack of the secondary circle, The gradient of such functional is computed by deriving a set of elliptic functions with respect both to their argument and to their Period. In the second case studied, we considered a wing-flap configuration. The circulation is computed by some implicit mappings, whose differentials with respect to the variation of the geometrical configuration in the physical space are found by divided differences. Configurations giving rise to local maxima and minima in the circulation manifold are presented.

  6. Osmium complex binding to mismatched methylcytosine: effect of adjacent bases.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-01-01

    We investigated the efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes depended on the 5'-neighboring base of the 5-methylcytosine. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique side reaction was observed. However, the mismatched base pairs did not influence the selectivity of osmium complexation with methylated DNA.

  7. Conference room 211, adjacent to commander's quarters, with vault door ...

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

    Conference room 211, adjacent to commander's quarters, with vault door at right. Projection area at center is equipped with automatic security drapes. Projection room uses a 45 degree mirror to reflect the image onto the frosted glass screen. Door on far left leads to display area senior battle staff viewing bridge, and the commander's quarters - March Air Force Base, Strategic Air Command, Combat Operations Center, 5220 Riverside Drive, Moreno Valley, Riverside County, CA

  8. 20. Interior view of fuel storage pit or vault adjacent ...

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

    20. Interior view of fuel storage pit or vault adjacent to Test Cell 9 in Component Test Laboratory (T-27), looking west. Photograph shows upgraded instrumentation, piping, tanks, and technological modifications installed in 1997-99 to accommodate component testing requirements for the Atlas V missile. - Air Force Plant PJKS, Systems Integration Laboratory, Components Test Laboratory, Waterton Canyon Road & Colorado Highway 121, Lakewood, Jefferson County, CO

  9. Four-body central configurations with adjacent equal masses

    NASA Astrophysics Data System (ADS)

    Deng, Yiyang; Li, Bingyu; Zhang, Shiqing

    2017-04-01

    For any convex non-collinear central configuration of the planar Newtonian 4-body problem with adjacent equal masses m1 =m2 ≠m3 =m4, with equal lengths for the two diagonals, we prove it must possess a symmetry and must be an isosceles trapezoid; furthermore, which is also an isosceles trapezoid when the length between m1 and m4 equals the length between m2 and m3.

  10. Processing multiple non-adjacent dependencies: evidence from sequence learning.

    PubMed

    de Vries, Meinou H; Petersson, Karl Magnus; Geukes, Sebastian; Zwitserlood, Pienie; Christiansen, Morten H

    2012-07-19

    Processing non-adjacent dependencies is considered to be one of the hallmarks of human language. Assuming that sequence-learning tasks provide a useful way to tap natural-language-processing mechanisms, we cross-modally combined serial reaction time and artificial-grammar learning paradigms to investigate the processing of multiple nested (A(1)A(2)A(3)B(3)B(2)B(1)) and crossed dependencies (A(1)A(2)A(3)B(1)B(2)B(3)), containing either three or two dependencies. Both reaction times and prediction errors highlighted problems with processing the middle dependency in nested structures (A(1)A(2)A(3)B(3)_B(1)), reminiscent of the 'missing-verb effect' observed in English and French, but not with crossed structures (A(1)A(2)A(3)B(1)_B(3)). Prior linguistic experience did not play a major role: native speakers of German and Dutch-which permit nested and crossed dependencies, respectively-showed a similar pattern of results for sequences with three dependencies. As for sequences with two dependencies, reaction times and prediction errors were similar for both nested and crossed dependencies. The results suggest that constraints on the processing of multiple non-adjacent dependencies are determined by the specific ordering of the non-adjacent dependencies (i.e. nested or crossed), as well as the number of non-adjacent dependencies to be resolved (i.e. two or three). Furthermore, these constraints may not be specific to language but instead derive from limitations on structured sequence learning.

  11. 38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX ...

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

    38. VIEW OF COTTRELL MAGNETIC IMPULSE GENERATOR ADJACENT TO SIX GAP ROTARY RECTIFIER. THIS UNIT GENERATED A MAGNETIC PULSE WHICH WAS TRANSMITTED TO THE COLLECTION PLATES IN THE ELECTROSTATIC PRECIPITATOR CHAMBER. THESE PERIODIC PULSES VIBRATE THE PLATES AND CAUSE PRECIPITATED ARTICLES OF SMOKE AND FLY ASH TO FALL TO THE BOTTOM OF THE PRECIPITATOR CHAMBER. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

  12. Intervertebral Disc Degeneration and Ectopic Bone Formation in Apolipoprotein E Knockout Mice

    PubMed Central

    Zhang, Dawei; Jin, Li; Reames, Davis L.; Shen, Francis H.; Shimer, Adam L.; Li, Xudong

    2012-01-01

    Cardiovascular risk factors are known to be associated with intervertebral disc degeneration, but the underlying mechanism is still unclear. ApoE knockout (KO) mouse is a well-established model for arthrosclerosis. We hypothesize that ApoE may involve in maintaining disc health and ApoE KO mouse develops early disc degeneration. Discs of ApoE KO and wild-type (WT) mice were characterized with histological/immunological, biochemical, and real time RT-PCR assays. A comparison of the extracellular matrix production was also performed in disc cells. We demonstrated that ApoE was highly expressed in the endplates of WT discs and ectopic bone formed in the endplates of ApoE KO discs. Glycosaminoglycan content was decreased in both ApoE KO annulus fibrosus (AF) and nucleus pulpsous (NP) cells. Collagen levels were increased in AF and decreased in NP cells. Matrix metalloproteinases-3, 9, and 13 expression was increased which may partially explain the impaired matrix production. We also found increased collagen I, II, aggrecan and biglycan mRNA expressions in AF cells but decreased in NP cells. Apoptosis was increased in the ApoE KO NP tissue. These results suggest early disc degeneration changes in ApoE KO mice. ApoE, plus its importance to cardiovascular disease, may play a critical role in disc integrity and function. PMID:22915292

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

    PubMed Central

    Risbud, Makarand V.; Shapiro, Irving. M

    2014-01-01

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

  14. Molecular Response of Chorioretinal Endothelial Cells to Complement Injury: Implications for Macular Degeneration

    PubMed Central

    Zeng, Shemin; Whitmore, S. Scott; Sohn, Elliott H.; Riker, Megan J.; Wiley, Luke A.; Scheetz, Todd E.; Stone, Edwin M.; Tucker, Budd A.; Mullins, Robert F.

    2016-01-01

    Age-related macular degeneration (AMD) is a common, blinding disease of the elderly in which macular photoreceptor cells, retinal pigment epithelium, and choriocapillaris endothelial cells ultimately degenerate. Recent studies have found that degeneration of the choriocapillaris occurs early in this disease and that this endothelial cell dropout is concomitant with increased deposition of the complement membrane attack complex (MAC) at the choroidal endothelium. However, the impact of MAC injury to choroidal endothelial cells is poorly understood. To model this event in vitro, and to study the downstream consequences of MAC injury, endothelial cells were exposed to complement from human serum, compared to heat inactivated serum which lacks complement components. Cells exposed to complement components in human serum showed increased labeling with antibodies directed against the MAC, time and dose dependent cell death as assessed by lactate dehydrogenase assay, and increased permeability. RNA-Seq analysis following complement injury revealed increased expression of genes associated with angiogenesis including matrix metalloproteases (MMPs) 3 and 9, and VEGF-A. The MAC-induced increase in MMP9 RNA expression was validated using C5 depleted serum compared to C5 reconstituted serum. Increased levels of MMP9 were also determined using Western blot and zymography. These data suggest that, in addition to cell lysis, complement attack on choroidal endothelial cells promotes an angiogenic phenotype in surviving cells. PMID:26564985

  15. Purkinje cell degeneration in mice lacking the xeroderma pigmentosum group G gene.

    PubMed

    Sun, X Z; Harada, Y N; Takahashi, S; Shiomi, N; Shiomi, T

    2001-05-15

    Laboratory mice carrying the nonfunctional xeroderma pigmentosum group G gene (the mouse counterpart of the human XPG gene) alleles have been generated by using gene-targeting and embryonic stem cell technology. Homozygote animals of this autosomal recessive disease exhibited signs and symptoms, such as postnatal growth retardation, reduced levels of activity, progressive ataxia and premature death, similar to the clinical manifestations of Cockayne syndrome (CS). Histological analysis of the cerebellum revealed multiple pyknotic cells in the Purkinje cell layer of the xpg homozygotes, which had atrophic cell bodies and shrunken nuclei. Further examination by an immunohistochemistry for calbindin-D 28k (CaBP) showed that a large number of immunoreactive Purkinje cells were atrophic and their dendritic trees were smaller and shorter than in wild-type littermates. These results indicated a marked degeneration of Purkinje cells in the xpg mutant cerebellum. Study by in situ detection of DNA fragmentation in the cerebellar cortex demonstrated that some deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin in situ nick labeling (TUNEL)-positive cells appeared in the granule layer of the mutant mice, but few cell deaths were confirmed in the Purkinje layer. These results suggested Purkinje cell degeneration in the mutant cerebellum was underway, in which much Purkinje cell death had not appeared, and the appearance of some abnormal cerebellar symptoms in the xpg-deficient mice was not only due to a marked Purkinje cell degeneration, but also to damage of other cells.

  16. Molecular response of chorioretinal endothelial cells to complement injury: implications for macular degeneration.

    PubMed

    Zeng, Shemin; Whitmore, S Scott; Sohn, Elliott H; Riker, Megan J; Wiley, Luke A; Scheetz, Todd E; Stone, Edwin M; Tucker, Budd A; Mullins, Robert F

    2016-02-01

    Age-related macular degeneration (AMD) is a common, blinding disease of the elderly in which macular photoreceptor cells, retinal pigment epithelium and choriocapillaris endothelial cells ultimately degenerate. Recent studies have found that degeneration of the choriocapillaris occurs early in this disease and that endothelial cell drop-out is concomitant with increased deposition of the complement membrane attack complex (MAC) at the choroidal endothelium. However, the impact of MAC injury to choroidal endothelial cells is poorly understood. To model this event in vitro, and to study the downstream consequences of MAC injury, endothelial cells were exposed to complement from human serum, compared to heat-inactivated serum, which lacks complement components. Cells exposed to complement components in human serum showed increased labelling with antibodies directed against the MAC, time- and dose-dependent cell death, as assessed by lactate dehydrogenase assay and increased permeability. RNA-Seq analysis following complement injury revealed increased expression of genes associated with angiogenesis including matrix metalloproteinase (MMP)-3 and -9, and VEGF-A. The MAC-induced increase in MMP9 RNA expression was validated using C5-depleted serum compared to C5-reconstituted serum. Increased levels of MMP9 were also established, using western blot and zymography. These data suggest that, in addition to cell lysis, complement attack on choroidal endothelial cells promotes an angiogenic phenotype in surviving cells.

  17. Statins for age-related macular degeneration

    PubMed Central

    Gehlbach, Peter; Li, Tianjing; Hatef, Elham

    2016-01-01

    Background Age-related macular degeneration (AMD) is a progressive late onset disorder of the macula affecting central vision. Age-related macular degeneration is the leading cause of blindness in people over 65 years in industrialized countries. Recent epidemiologic, genetic, and pathological evidence has shown AMD shares a number of risk factors with atherosclerosis, leading to the hypothesis that statins may exert protective effects in AMD. Objectives The objective of this review was to examine the effectiveness of statins compared with other treatments, no treatment, or placebo in delaying the onset and progression of AMD. Search methods We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 6), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to June 2014), EMBASE (January 1980 to June 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to June 2014), PubMed (January 1946 to June 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 5 June 2014. Selection criteria We included randomized controlled trials (RCTs) that compared statins with other treatments, no treatment, or placebo in participants who were either susceptible to or diagnosed as having early stages of AMD. Data collection and analysis We used standard methodological procedures expected by The Cochrane Collaboration. Two authors independently evaluated the search results against the selection criteria, abstracted data, and assessed risk of bias. We did not perform meta-analysis due to heterogeneity in the interventions and outcomes among the

  18. Divergent viral presentation among human tumors and adjacent normal tissues

    PubMed Central

    Cao, Song; Wendl, Michael C.; Wyczalkowski, Matthew A.; Wylie, Kristine; Ye, Kai; Jayasinghe, Reyka; Xie, Mingchao; Wu, Song; Niu, Beifang; Grubb, Robert; Johnson, Kimberly J.; Gay, Hiram; Chen, Ken; Rader, Janet S.; Dipersio, John F.; Chen, Feng; Ding, Li

    2016-01-01

    We applied a newly developed bioinformatics system called VirusScan to investigate the viral basis of 6,813 human tumors and 559 adjacent normal samples across 23 cancer types and identified 505 virus positive samples with distinctive, organ system- and cancer type-specific distributions. We found that herpes viruses (e.g., subtypes HHV4, HHV5, and HHV6) that are highly prevalent across cancers of the digestive tract showed significantly higher abundances in tumor versus adjacent normal samples, supporting their association with these cancers. We also found three HPV16-positive samples in brain lower grade glioma (LGG). Further, recurrent HBV integration at the KMT2B locus is present in three liver tumors, but absent in their matched adjacent normal samples, indicating that viral integration induced host driver genetic alterations are required on top of viral oncogene expression for initiation and progression of liver hepatocellular carcinoma. Notably, viral integrations were found in many genes, including novel recurrent HPV integrations at PTPN13 in cervical cancer. Finally, we observed a set of HHV4 and HBV variants strongly associated with ethnic groups, likely due to viral sequence evolution under environmental influences. These findings provide important new insights into viral roles of tumor initiation and progression and potential new therapeutic targets. PMID:27339696

  19. Predicting Agenesis of the Mandibular Second Premolar from Adjacent Teeth

    PubMed Central

    2015-01-01

    Early diagnosis of agenesis of the mandibular second premolar (P2) enhances management of the dental arch in the growing child. The aim of this study was to explore the relationship in the development of the mandibular first molar (M1) and first premolar (P1) at early stages of P2 (second premolar). Specifically, we ask if the likelihood of P2 agenesis can be predicted from adjacent developing teeth. We selected archived dental panoramic radiographs with P2 at crown formation stages (N = 212) and calculated the likelihood of P2 at initial mineralisation stage ‘Ci’ given the tooth stage of adjacent teeth. Our results show that the probability of observing mandibular P2 at initial mineralisation stage ‘Ci’ decreased as both the adjacent P1 and M1 matured. The modal stage at P2 ‘Ci’ was P1 ‘Coc’ (cusp outline complete) and M1 ‘Crc’ (crown complete). Initial mineralisation of P2 was observed up to P1 ‘Crc’ and M1 stage ‘R½’ (root half). The chance of observing P2 at least ‘Coc’ (coalescence of cusps) was considerably greater prior to these threshold stages compared to later stages of P1 and M1. These findings suggest that P2 is highly unlikely to develop if P1 is beyond ‘Crc’ and M1 is beyond ‘R½’. PMID:26673218

  20. Fouling assemblages on offshore wind power plants and adjacent substrata

    NASA Astrophysics Data System (ADS)

    Wilhelmsson, Dan; Malm, Torleif

    2008-09-01

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  1. Using BRDFs for accurate albedo calculations and adjacency effect corrections

    SciTech Connect

    Borel, C.C.; Gerstl, S.A.W.

    1996-09-01

    In this paper the authors discuss two uses of BRDFs in remote sensing: (1) in determining the clear sky top of the atmosphere (TOA) albedo, (2) in quantifying the effect of the BRDF on the adjacency point-spread function and on atmospheric corrections. The TOA spectral albedo is an important parameter retrieved by the Multi-angle Imaging Spectro-Radiometer (MISR). Its accuracy depends mainly on how well one can model the surface BRDF for many different situations. The authors present results from an algorithm which matches several semi-empirical functions to the nine MISR measured BRFs that are then numerically integrated to yield the clear sky TOA spectral albedo in four spectral channels. They show that absolute accuracies in the albedo of better than 1% are possible for the visible and better than 2% in the near infrared channels. Using a simplified extensive radiosity model, the authors show that the shape of the adjacency point-spread function (PSF) depends on the underlying surface BRDFs. The adjacency point-spread function at a given offset (x,y) from the center pixel is given by the integral of transmission-weighted products of BRDF and scattering phase function along the line of sight.

  2. Inflammation and white matter degeneration persist for years after a single traumatic brain injury.

    PubMed

    Johnson, Victoria E; Stewart, Janice E; Begbie, Finn D; Trojanowski, John Q; Smith, Douglas H; Stewart, William

    2013-01-01

    A single traumatic brain injury is associated with an increased risk of dementia and, in a proportion of patients surviving a year or more from injury, the development of hallmark Alzheimer's disease-like pathologies. However, the pathological processes linking traumatic brain injury and neurodegenerative disease remain poorly understood. Growing evidence supports a role for neuroinflammation in the development of Alzheimer's disease. In contrast, little is known about the neuroinflammatory response to brain injury and, in particular, its temporal dynamics and any potential role in neurodegeneration. Cases of traumatic brain injury with survivals ranging from 10 h to 47 years post injury (n = 52) and age-matched, uninjured control subjects (n = 44) were selected from the Glasgow Traumatic Brain Injury archive. From these, sections of the corpus callosum and adjacent parasaggital cortex were examined for microglial density and morphology, and for indices of white matter pathology and integrity. With survival of ≥3 months from injury, cases with traumatic brain injury frequently displayed extensive, densely packed, reactive microglia (CR3/43- and/or CD68-immunoreactive), a pathology not seen in control subjects or acutely injured cases. Of particular note, these reactive microglia were present in 28% of cases with survival of >1 year and up to 18 years post-trauma. In cases displaying this inflammatory pathology, evidence of ongoing white matter degradation could also be observed. Moreover, there was a 25% reduction in the corpus callosum thickness with survival >1 year post-injury. These data present striking evidence of persistent inflammation and ongoing white matter degeneration for many years after just a single traumatic brain injury in humans. Future studies to determine whether inflammation occurs in response to or, conversely, promotes white matter degeneration will be important. These findings may provide parallels for studying neurodegenerative disease

  3. Deletion of autophagy inducer RB1CC1 results in degeneration of the retinal pigment epithelium.

    PubMed

    Yao, Jingyu; Jia, Lin; Khan, Naheed; Lin, Chengmao; Mitter, Sayak K; Boulton, Michael E; Dunaief, Joshua L; Klionsky, Daniel J; Guan, Jun-Lin; Thompson, Debra A; Zacks, David N

    2015-01-01

    Autophagy regulates cellular homeostasis and response to environmental stress. Within the retinal pigment epithelium (RPE) of the eye, the level of autophagy can change with both age and disease. The purpose of this study is to determine the relationship between reduced autophagy and age-related degeneration of the RPE. The gene encoding RB1CC1/FIP200 (RB1-inducible coiled-coil 1), a protein essential for induction of autophagy, was selectively knocked out in the RPE by crossing Best1-Cre mice with mice in which the Rb1cc1 gene was flanked with Lox-P sites (Rb1cc1(flox/flox)). Ex vivo and in vivo analyses, including western blot, immunohistochemistry, transmission electron microscopy, fundus photography, optical coherence tomography, fluorescein angiography, and electroretinography were performed to assess the structure and function of the retina as a function of age. Deletion of Rb1cc1 resulted in multiple autophagy defects within the RPE including decreased conversion of LC3-I to LC3-II, accumulation of autophagy-targeted precursors, and increased numbers of mitochondria. Age-dependent degeneration of the RPE occurred, with formation of atrophic patches, subretinal migration of activated microglial cells, subRPE deposition of inflammatory and oxidatively damaged proteins, subretinal drusenoid deposits, and occasional foci of choroidal neovascularization. There was secondary loss of photoreceptors overlying the degenerated RPE and reduction in the electroretinogram. These observations are consistent with a critical role of autophagy in the maintenance of normal homeostasis in the aging RPE, and indicate that disruption of autophagy leads to retinal phenotypes associated with age-related degeneration.

  4. Adjacent disc height reduction and clinical outcome after intradiscal cement leakage

    PubMed Central

    Shen, Minjie; Niu, Junjie; Zhou, Haifei; Meng, Qian; Gan, Minfeng

    2016-01-01

    Objective The purpose of this study is to evaluate the effect of intradiscal cement leakage on the height of adjacent cement-containing discs and the resulting clinical efficacy after kyphoplasty. Methods A total of 124 patients were included and classified into two groups: group A included 20 patients with intradiscal leakage, and group B contained 104 patients without intradiscal leakage. The mean follow-up time was 20.56±3.51 months. The height of the corresponding discs in both groups was measured using Farfan’s method. Clinical efficacy was assessed using the Visual Analog Scale and Oswestry Disability Index scores at each follow-up time. Results The anterior disc height, posterior disc height and Farfan Index significantly decreased in both groups at last follow-up. The disc height reduction was 9.19±2.89% in group A and 3.88±2.70% in group B, which was significantly different between the groups (P<0.01). The disc height reduction rate was 29.39±7.90% in group A and 12.75±8.18% in group B, which was also a statistically significant difference (P<0.01). The VAS and ODI scores improved significantly after surgery and maintained at last follow-up, and there was no statistically significant difference between Groups A and B. Conclusion Intradiscal cement leakage was associated with the degeneration of cement-containing disc but did not reduce the clinical efficacy at early stages. PMID:27909655

  5. Nutritional Modulation of Age-Related Macular Degeneration

    PubMed Central

    Weikel, Karen A; Taylor, Allen

    2012-01-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30–50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated with AMD are in excess of $340 billion US (American-Health-Assistance-Foundation, 2012). The majority of AMD patients in the United States are not eligible for clinical treatments (Biarnes et al., 2011; Klein et al., 2011). Preventive interventions through dietary modulation are attractive strategies because many studies suggest a benefit of micro and macronutrients with respect to AMD, as well as other age-related debilities, and with few, if any, adverse effects (Chiu, 2011). Preservation of vision would enhance quality of life for millions of elderly people, and alleviate the personal and public health financial burden of AMD (Frick et al., 2007; Wood et al., 2011). Observational studies indicate that maintaining adequate levels of omega-3 fatty acids (i.e. with 2 servings/wk of fish) or a low glycemic index diet may be particularly beneficial for early AMD and that higher levels of carotenoids may be protective, most probably, against neovascular AMD. Intervention trials are needed to better understand the full effect of these nutrients and/or combinations of nutrients on retinal health. Analyses that describe effects of a nutrient on onset and/or progress of AMD are valuable because they indicate the value of a nutrient to arrest AMD at the early stages. This comprehensive summary provides essential information about the value of nutrients with regard to diminishing risk for onset or progress of AMD and can serve as a guide until data from ongoing intervention trials are available. PMID:22503690

  6. Nutritional modulation of age-related macular degeneration.

    PubMed

    Weikel, Karen A; Chiu, Chung-Jung; Taylor, Allen

    2012-08-01

    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated with AMD are in excess of $340 billion US (American-Health-Assistance-Foundation, 2012). The majority of AMD patients in the United States are not eligible for clinical treatments (Biarnes et al., 2011; Klein et al., 2011). Preventive interventions through dietary modulation are attractive strategies because many studies suggest a benefit of micro- and macronutrients with respect to AMD, as well as other age-related debilities, and with few, if any, adverse effects (Chiu, 2011). Preservation of vision would enhance quality of life for millions of elderly people, and alleviate the personal and public health financial burden of AMD (Frick et al., 2007; Wood et al., 2011). Observational studies indicate that maintaining adequate levels of omega-3 fatty acids (i.e. with 2 servings/week of fish) or a low glycemic index diet may be particularly beneficial for early AMD and that higher levels of carotenoids may be protective, most probably, against neovascular AMD. Intervention trials are needed to better understand the full effect of these nutrients and/or combinations of nutrients on retinal health. Analyses that describe effects of a nutrient on onset and/or progress of AMD are valuable because they indicate the value of a nutrient to arrest AMD at the early stages. This comprehensive summary provides essential information about the value of nutrients with regard to diminishing risk for onset or progress of AMD and can serve as a guide until data from ongoing intervention trials are available.

  7. Mechanisms of Distal Axonal Degeneration in Peripheral Neuropathies

    PubMed Central

    Cashman, Christopher R.; Höke, Ahmet

    2015-01-01

    Peripheral neuropathy is a common complication of a variety of diseases and treatments, including diabetes, cancer chemotherapy, and infectious causes (HIV, hepatitis C, and Campylobacter jejuni). Despite the fundamental difference between these insults, peripheral neuropathy develops as a combination of just six primary mechanisms: altered metabolism, covalent modification, altered organelle function and reactive oxygen species formation, altered intracellular and inflammatory signaling, slowed axonal transport, and altered ion channel dynamics and expression. All of these pathways converge to lead to axon dysfunction and symptoms of neuropathy. The detailed mechanisms of axon degeneration itself have begun to be elucidated with studies of animal models with altered degeneration kinetics, including the slowed Wallerian degeneration (Wlds) and Sarmknockout animal models. These studies have shown axonal degeneration to occur througha programmed pathway of injury signaling and cytoskeletal degradation. Insights into the common disease insults that converge on the axonal degeneration pathway promise to facilitate the development of therapeutics that may be effective against other mechanisms of neurodegeneration. PMID:25617478

  8. Notochord Cells in Intervertebral Disc Development and Degeneration

    PubMed Central

    McCann, Matthew R.; Séguin, Cheryle A.

    2016-01-01

    The intervertebral disc is a complex structure responsible for flexibility, multi-axial motion, and load transmission throughout the spine. Importantly, degeneration of the intervertebral disc is thought to be an initiating factor for back pain. Due to a lack of understanding of the pathways that govern disc degeneration, there are currently no disease-modifying treatments to delay or prevent degenerative disc disease. This review presents an overview of our current understanding of the developmental processes that regulate intervertebral disc formation, with particular emphasis on the role of the notochord and notochord-derived cells in disc homeostasis and how their loss can result in degeneration. We then describe the role of small animal models in understanding the development of the disc and their use to interrogate disc degeneration and associated pathologies. Finally, we highlight essential development pathways that are associated with disc degeneration and/or implicated in the reparative response of the tissue that might serve as targets for future therapeutic approaches. PMID:27252900

  9. Transplantation and Stem Cell Therapy for Cerebellar Degenerations.

    PubMed

    Cendelin, Jan

    2016-02-01

    Stem cell-based and regenerative therapy may become a hopeful treatment for neurodegenerative diseases including hereditary cerebellar degenerations. Neurotransplantation therapy mainly aims to substitute lost cells, but potential effects might include various mechanisms including nonspecific trophic effects and stimulation of endogenous regenerative processes and neural plasticity. Nevertheless, currently, there remain serious limitations. There is a wide spectrum of human hereditary cerebellar degenerations as well as numerous cerebellar mutant mouse strains that serve as models for the development of effective therapy. By now, transplantation has been shown to ameliorate cerebellar function, e.g. in Purkinje cell degeneration mice, Lurcher mutant mice and mouse models of spinocerebellar ataxia type 1 and type 2 and Niemann-Pick disease type C. Despite the lack of direct comparative studies, it appears that there might be differences in graft development and functioning between various types of cerebellar degeneration. Investigation of the relation of graft development to specific morphological, microvascular or biochemical features of the diseased host tissue in various cerebellar degenerations may help to identify factors determining the fate of grafted cells and potential of their functional integration.

  10. Rapid Y degeneration and dosage compensation in plant sex chromosomes.

    PubMed

    Papadopulos, Alexander S T; Chester, Michael; Ridout, Kate; Filatov, Dmitry A

    2015-10-20

    The nonrecombining regions of animal Y chromosomes are known to undergo genetic degeneration, but previous work has failed to reveal large-scale gene degeneration on plant Y chromosomes. Here, we uncover rapid and extensive degeneration of Y-linked genes in a plant species, Silene latifolia, that evolved sex chromosomes de novo in the last 10 million years. Previous transcriptome-based studies of this species missed unexpressed, degenerate Y-linked genes. To identify sex-linked genes, regardless of their expression, we sequenced male and female genomes of S. latifolia and integrated the genomic contigs with a high-density genetic map. This revealed that 45% of Y-linked genes are not expressed, and 23% are interrupted by premature stop codons. This contrasts with X-linked genes, in which only 1.3% of genes contained stop codons and 4.3% of genes were not expressed in males. Loss of functional Y-linked genes is partly compensated for by gene-specific up-regulation of X-linked genes. Our results demonstrate that the rate of genetic degeneration of Y-linked genes in S. latifolia is as fast as in animals, and that the evolutionary trajectories of sex chromosomes are similar in the two kingdoms.

  11. RADIOLOGICAL ANALYSIS OF EXPERIMENTAL DISC DEGENERATION IN RABBITS

    PubMed Central

    Vialle, Emiliano; Vialle, Luiz Roberto; Arruda, André de Oliveira; Riet, Ricardo Nascimento; Krieger, Antônio Bernardo de Queiroz

    2015-01-01

    Objective: To validate radiographic evaluation of a rabbit model for disc degeneration. Methods: Lumbar intervertebral discs of New Zealand rabbits were stabbed three times with a 18G needle at a limited depth of 5mm, through lateral approach. Serial radiographic images were taken on the early pre-and postoperative periods, and after four, eight and 12 weeks of the procedure, with subsequent analysis of disc height, osteophyte formation, endplate sclerosis, and presence of disc degeneration. The statistical analysis of data was validated by the Kappa coefficient, with a confidence interval (CI) of 95%. Results: A significant reduction of disc space was found on AP X-ray images after 12 postoperative weeks, with Kappa = 0.489 for CI 95% (0.25-0.72) with p < 0.001. X-ray signs of disc degeneration also presented Kappa = 0.63 for CI 95% (0.39-0.86) with p < 0.001. The remaining assessed criteria showed positive results, but with a lower Kappa value. Conclusion: The disc degeneration model using rabbits as proposed in this study was shown to be feasible, with positive X-ray correlation between pre- and postoperative images, validating the potential to induce disc degeneration in this animal model for future studies. PMID:27022512

  12. Review: Retinal degeneration: Focus on the unfolded protein response

    PubMed Central

    Gorbatyuk, Oleg

    2013-01-01

    Recently published literature has provided evidence that the unfolded protein response (UPR) is involved in the development of retinal degeneration. The scope of these studies encompassed diabetic retinopathy, retinopathy of prematurity, glaucoma, retinal detachment, light-induced retinal degeneration, age-related macular degeneration, and inherited retinal degeneration. Subsequent studies investigating the role of individual UPR markers in retinal pathogenesis and examining the therapeutic potential of reprogramming the UPR as a method for modulating the rate of retinal degeneration have been initiated. Manipulation of UPR markers has been made possible by the use of knockout mice, pharmacological agents, and viral vector-mediated augmentation of gene expression. Future research will aim at identifying specific inhibitors and/or inducers of UPR regulatory markers as well as expand the list of UPR-related animal models. Additionally, adeno-associated virus-mediated gene delivery is a safe and effective method for modulating gene expression, and thus is a useful research tool for manipulating individual UPR markers in affected retinas and a promising delivery vector for gene therapy in retinal degenerative disorders. PMID:24068865

  13. NMN Deamidase Delays Wallerian Degeneration and Rescues Axonal Defects Caused by NMNAT2 Deficiency In Vivo.

    PubMed

    Di Stefano, Michele; Loreto, Andrea; Orsomando, Giuseppe; Mori, Valerio; Zamporlini, Federica; Hulse, Richard P; Webster, Jamie; Donaldson, Lucy F; Gering, Martin; Raffaelli, Nadia; Coleman, Michael P; Gilley, Jonathan; Conforti, Laura

    2017-03-20

    Axons require the axonal NAD-synthesizing enzyme NMNAT2 to survive. Injury or genetically induced depletion of NMNAT2 triggers axonal degeneration or defective axon growth. We have previously proposed that axonal NMNAT2 primarily promotes axon survival by maintaining low levels of its substrate NMN rather than generating NAD; however, this is still debated. NMN deamidase, a bacterial enzyme, shares NMN-consuming activity with NMNAT2, but not NAD-synthesizing activity, and it delays axon degeneration in primary neuronal cultures. Here we show that NMN deamidase can also delay axon degeneration in zebrafish larvae and in transgenic mice. Like overexpressed NMNATs, NMN deamidase reduces NMN accumulation in injured mouse sciatic nerves and preserves some axons for up to three weeks, even when expressed at a low level. Remarkably, NMN deamidase also rescues axonal outgrowth and perinatal lethality in a dose-dependent manner in mice lacking NMNAT2. These data further support a pro-degenerative effect of accumulating NMN in axons in vivo. The NMN deamidase mouse will be an important tool to further probe the mechanisms underlying Wallerian degeneration and its prevention.

  14. The Role of Posttraumatic Hypothermia in Preventing Dendrite Degeneration and Spine Loss after Severe Traumatic Brain Injury

    PubMed Central

    Wang, Chuan-fang; Zhao, Cheng-cheng; Jiang, Gan; Gu, Xiao; Feng, Jun-feng; Jiang, Ji-yao

    2016-01-01

    Posttraumatic hypothermia prevents cell death and promotes functional outcomes after traumatic brain injury (TBI). However, little is known regarding the effect of hypothermia on dendrite degeneration and spine loss after severe TBI. In the present study, we used thy1-GFP transgenic mice to investigate the effect of hypothermia on the dendrites and spines in layer V/VI of the ipsilateral cortex after severe TBI. We found that hypothermia (33 °C) dramatically prevented dendrite degeneration and spine loss 1 and 7 days after CCI. The Morris water maze test revealed that hypothermia preserved the learning and memory functions of mice after CCI. Hypothermia significantly increased the expression of the synaptic proteins GluR1 and PSD-95 at 1 and 7 days after CCI in the ipsilateral cortex and hippocampus compared with that of the normothermia TBI group. Hypothermia also increased cortical and hippocampal BDNF levels. These results suggest that posttraumatic hypothermia is an effective method to prevent dendrite degeneration and spine loss and preserve learning and memory function after severe TBI. Increasing cortical and hippocampal BDNF levels might be the mechanism through which hypothermia prevents dendrite degeneration and spine loss and preserves learning and memory function. PMID:27833158

  15. Electrophysiology Alterations in Primary Visual Cortex Neurons of Retinal Degeneration (S334ter-line-3) Rats

    PubMed Central

    Chen, Ke; Wang, Yi; Liang, Xiaohua; Zhang, Yihuai; Ng, Tsz Kin; Chan, Leanne Lai Hang

    2016-01-01

    The dynamic nature of the brain is critical for the success of treatments aimed at restoring vision at the retinal level. The success of these treatments relies highly on the functionality of the surviving neurons along the entire visual pathway. Electrophysiological properties at the retina level have been investigated during the progression of retinal degeneration; however, little is known about the changes in electrophysiological properties that occur in the primary visual cortex (V1) during the course of retinal degeneration. By conducting extracellular recording, we examined the electrophysiological properties of V1 in S334ter-line-3 rats (a transgenic model of retinal degeneration developed to express a rhodopsin mutation similar to that found in human retinitis pigmentosa patients). We measured the orientation tuning, spatial and temporal frequency tunings and the receptive field (RF) size for 127 V1 neurons from 11 S334ter-3 rats and 10 Long-Evans (LE) rats. V1 neurons in the S334ter-3 rats showed weaker orientation selectivity, lower optimal spatial and temporal frequency values and a smaller receptive field size compared to the LE rats. These results suggest that the visual cognitive ability significantly changes during retinal degeneration. PMID:27225415

  16. Records of selected wells and lithologic logs of test holes, Hendry County and adjacent areas, Florida

    USGS Publications Warehouse

    Fish, John E.; Causaras, Carmen R.; O'Donnell, T. H.

    1983-01-01

    To provide water-resource information for Hendry County, Florida , geologic test holes were drilled in the surficial aquifer, and an extensive inventory was compiled of wells in the surficial aquifer and deep artesian aquifers. This report provides: (1) records for 788 selected wells and test holes including location , construction, water use, water level, chloride concentration, specific conductance, temperature, yield, hydrogen sulfide, and iron-staining problems; and (2) lithologic logs for 26 test holes ranging in depth from 90 to 650 feet. A few inventoried wells and two test holes are in adjacent parts of Collier or Glades Counties. (USGS)

  17. Glial fibrillar acidic protein in the cerebrospinal fluid of Alzheimer's disease, dementia with Lewy bodies, and frontotemporal lobar degeneration.

    PubMed

    Ishiki, Aiko; Kamada, Maki; Kawamura, Yuki; Terao, Chiaki; Shimoda, Fumiko; Tomita, Naoki; Arai, Hiroyuki; Furukawa, Katsutoshi

    2016-01-01

    Biomarkers in the cerebrospinal fluid (CSF) are currently regarded as indispensable indicators for accurate differential diagnosis of neurodegenerative disorders. Although high levels of astrocyte-secreted glial fibrillar acidic protein (GFAP) in the CSF of patients with Alzheimer's disease (AD) have been reported, the levels of GFAP in the CSF have not been fully investigated in other neurological disorders that cause dementia, such as dementia with Lewy bodies (DLB) and frontotemporal lobar degeneration (FTLD). In this study, we determined the levels of GFAP in the CSF of healthy control subjects and AD, DLB, and FTLD patients to address two questions: (i) Do the levels of GFAP differ among these disorders? and (ii) Can GFAP be used as a biomarker for the differential diagnosis of these neurodegenerative disorders? The levels of GFAP in AD, DLB, and FTLD patients were significantly higher than those in the healthy control subjects. Although the levels of GFAP were not significantly different between AD and DLB patients, a higher level of GFAP was observed in FTLD patients than in AD and DLB patients. It is concluded that representative neurological disorders causing dementia were associated with higher levels of GFAP in the CSF. We propose the following mechanism concerning the amount of glial fibrillar acidic protein (GFAP) in the cerebrospinal fluid (CSF) in Alzheimer's disease (AD), dementia with Lewy bodies (DLB), and frontotemporal lobar degeneration (FTLD). The increase in the release of GFAP into CSF is considered to reflect the sum of degeneration of astrocytes and astrocytosis. The sum of degeneration and astrocytosis or the GFAP release could be in the order of FTLD > DLB > AD > normal condition.

  18. Degeneration of penicillin production in ethanol-limited chemostat cultivations of Penicillium chrysogenum: A systems biology approach

    PubMed Central

    2011-01-01

    Background In microbial production of non-catabolic products such as antibiotics a loss of production capacity upon long-term cultivation (for example chemostat), a phenomenon called strain degeneration, is often observed. In this study a systems biology approach, monitoring changes from gene to produced flux, was used to study degeneration of penicillin production in a high producing Penicillium chrysogenum strain during prolonged ethanol-limited chemostat cultivations. Results During these cultivations, the biomass specific penicillin production rate decreased more than 10-fold in less than 22 generations. No evidence was obtained for a decrease of the copy number of the penicillin gene cluster, nor a significant down regulation of the expression of the penicillin biosynthesis genes. However, a strong down regulation of the biosynthesis pathway of cysteine, one of the precursors of penicillin, was observed. Furthermore the protein levels of the penicillin pathway enzymes L-α-(δ-aminoadipyl)-L-α-cystenyl-D-α-valine synthetase (ACVS) and isopenicillin-N synthase (IPNS), decreased significantly. Re-cultivation of fully degenerated cells in unlimited batch culture and subsequent C-limited chemostats did only result in a slight recovery of penicillin production. Conclusions Our findings indicate that the observed degeneration is attributed to a significant decrease of the levels of the first two enzymes of the penicillin biosynthesis pathway, ACVS and IPNS. This decrease is not caused by genetic instability of the penicillin amplicon, neither by down regulation of the penicillin biosynthesis pathway. Furthermore no indications were obtained for degradation of these enzymes as a result of autophagy. Possible causes for the decreased enzyme levels could be a decrease of the translation efficiency of ACVS and IPNS during degeneration, or the presence of a culture variant impaired in the biosynthesis of functional proteins of these enzymes, which outcompeted the high

  19. Tissue and urokinase plasminogen activators instigate the degeneration of retinal ganglion cells in a mouse model of glaucoma

    PubMed Central

    Chintala, Shravan K

    2015-01-01

    Elevated intraocular pressure (IOP) promotes the degeneration of retinal ganglion cells (RGCs) during the progression of Primary Open-Angle Glaucoma (POAG). However, the molecular mechanisms underpinning IOP-mediated degeneration of RGCs remain unclear. Therefore, by employing a mouse model of POAG, this study examined whether elevated IOP promotes the degeneration of RGCs by up-regulating tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) in the retina. IOP was elevated in mouse eyes by injecting fluorescent-microbeads into the anterior chamber. Once a week, for eight weeks, IOP in mouse eyes was measured by using Tono-Pen XL. At various time periods after injecting microbeads, proteolytic activity of tPA and uPA in retinal protein extracts was determined by fibrinogen/plasminogen zymography assays. Localization of tPA and uPA, and their receptor LRP-1 (low-density receptor-related protein-1) in the retina was determined by immunohistochemistry. RGCs’ degeneration was assessed by immunostaining with antibodies against Brn3a. Injection of microbeads into the anterior chamber led to a progressive elevation in IOP, increased the proteolytic activity of tPA and uPA in the retina, activated plasminogen into plasmin, and promoted a significant degeneration of RGCs. Elevated IOP up-regulated tPA and LRP-1 in RGCs, and uPA in astrocytes. At four weeks after injecting microbeads, RAP (receptor associated protein; 0.5 and 1.0 μM) or tPA-Stop (1.0 and 4.0 μM) was injected into the vitreous humor. Treatment of IOP-elevated eyes with RAP led to a significant decrease in proteolytic activity of both tPA and uPA, and a significant decrease in IOP-mediated degeneration of RGCs. Also, treatment of IOP-elevated eyes with tPA-Stop decreased the proteolytic activity of both tPA and uPA, and, in turn, significantly attenuated IOP-mediated degeneration of RGCs. Results presented in this study provide evidence that elevated IOP promotes the degeneration of

  20. Developments in age-related macular degeneration: Diagnosis and treatment.

    PubMed

    Kaufman, Steven R

    2009-03-01

    Age-related macular degeneration (ARMD) is the leading cause of legal blindness of Americans over age 65 years. Severe loss of vision is usually due to exudative ARMD, of which there are about 200,000 new cases in the United States annually. Until recently, only a small fraction of patients benefited from treatment, but advances in the early diagnosis of the disease and major developments in therapy have substantially improved the prognosis of patients with ARMD. Because visual loss substantially reduces quality of life, effective management of ARMD will have increasing public health importance as the population ages. The American Academy of Ophthalmology recommends that people over age 65 years should have a comprehensive eye examination every 1 to 2 years to check for cataracts, macular degeneration, glaucoma, and other conditions. Those who complain of difficulty reading, driving at night, or adapting from sunlight to indoor lighting might have macular degeneration.

  1. Electromagnetic wave equations for relativistically degenerate quantum magnetoplasmas

    SciTech Connect

    Masood, Waqas; Eliasson, Bengt; Shukla, Padma K.

    2010-06-15

    A generalized set of nonlinear electromagnetic quantum hydrodynamic (QHD) equations is derived for a magnetized quantum plasma, including collisional, electron spin-(1/2), and relativistically degenerate electron pressure effects that are relevant for dense astrophysical systems, such as white dwarfs. For illustrative purposes, linear dispersion relations are derived for one-dimensional magnetoacoustic waves for a collisionless nonrelativistic degenerate gas in the presence of the electron spin-(1/2) contribution and for magnetoacoustic waves in a plasma containing relativistically degenerate electrons. It is found that both the spin and relativistic degeneracy at high densities tend to slow down the magnetoacoustic wave due to the Pauli paramagnetic effect and relativistic electron mass increase. The present study outlines the theoretical framework for the investigation of linear and nonlinear behaviors of electromagnetic waves in dense astrophysical systems. The results are applied to calculate the magnetoacoustic speeds for both the nonrelativistic and relativistic electron degeneracy cases typical for white dwarf stars.

  2. Electromagnetic wave equations for relativistically degenerate quantum magnetoplasmas.

    PubMed

    Masood, Waqas; Eliasson, Bengt; Shukla, Padma K

    2010-06-01

    A generalized set of nonlinear electromagnetic quantum hydrodynamic (QHD) equations is derived for a magnetized quantum plasma, including collisional, electron spin- 1/2, and relativistically degenerate electron pressure effects that are relevant for dense astrophysical systems, such as white dwarfs. For illustrative purposes, linear dispersion relations are derived for one-dimensional magnetoacoustic waves for a collisionless nonrelativistic degenerate gas in the presence of the electron spin- 1/2 contribution and for magnetoacoustic waves in a plasma containing relativistically degenerate electrons. It is found that both the spin and relativistic degeneracy at high densities tend to slow down the magnetoacoustic wave due to the Pauli paramagnetic effect and relativistic electron mass increase. The present study outlines the theoretical framework for the investigation of linear and nonlinear behaviors of electromagnetic waves in dense astrophysical systems. The results are applied to calculate the magnetoacoustic speeds for both the nonrelativistic and relativistic electron degeneracy cases typical for white dwarf stars.

  3. Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study

    PubMed Central

    Cavallini, Costanza; Vernucci, Roberto; Vichi, Maurizio; Leonardi, Rosalia; Barbato, Ersilia

    2016-01-01

    /impacted canine analysed on orthopantomographs could be one of the evaluation criteria for prescribing second level examination (CT and CTCB) and for detecting root resorption of impacted maxillary canine adjacent teeth. Key words:Impacted canine, root resorption, panoramic radiography, angulation, prediction. PMID:27694788

  4. CKD increases the risk of age-related macular degeneration.

    PubMed

    Liew, Gerald; Mitchell, Paul; Wong, Tien Yin; Iyengar, Sudha K; Wang, Jie Jin

    2008-04-01

    Age-related macular degeneration is the leading cause of irreversible blindness in the United States and often coexists with chronic kidney disease. Both conditions share common genetic and environmental risk factors. A total of 1183 participants aged 54+ were examined in the population-based, prospective cohort Blue Mountains Eye Study (Australia) to determine if chronic kidney disease increases the risk of age-related macular degeneration. Moderate chronic kidney disease (estimated glomerular filtration rate < 60 ml/min per 1.73 m(2) based on the Cockcroft-Gault equation) was present in 24% of the population (286 of 1183). The 5-yr incidence of early age-related macular degeneration was 3.9% in participants with no/mild chronic kidney disease (35 of 897) and 17.5% in those with moderate chronic kidney disease (50 of 286). After adjusting for age, sex, cigarette smoking, hypertension, complement factor H polymorphism, and other risk factors, persons with moderate chronic kidney disease were 3 times more likely to develop early age-related macular degeneration than persons with no/mild chronic kidney disease (odds ratio = 3.2; 95% confidence interval, 1.8 to 5.7, P < 0.0001). Each SD (14.8 ml/min per 1.73 m(2)) decrease in Cockcroft-Gault estimated glomerular filtration rate was associated with a doubling of the adjusted risk for early age-related macular degeneration (odds ratio = 2.0; 95% confidence interval, 1.5 to 2.8, P < 0.0001). In conclusion, persons with chronic kidney disease have a higher risk of early age-related macular degeneration, suggesting the possibility of shared pathophysiologic mechanisms between the two conditions.

  5. OBSERVATIONAL CONSTRAINTS ON THE DEGENERATE MASS-RADIUS RELATION

    SciTech Connect

    Holberg, J. B.; Oswalt, T. D.; Barstow, M. A. E-mail: toswalt@fit.edu

    2012-03-15

    The white dwarf mass-radius relationship is fundamental to modern astrophysics. It is central to routine estimation of DA white dwarf masses derived from spectroscopic temperatures and gravities. It is also the basis for observational determinations of the white dwarf initial-final-mass relation. Nevertheless, definitive and detailed observational confirmations of the mass-radius relation (MRR) remain elusive owing to a lack of sufficiently accurate white dwarf masses and radii. Current best estimates of masses and radii allow only broad conclusions about the expected inverse relation between masses and radii in degenerate stars. In this paper, we examine a restricted set of 12 DA white dwarf binary systems for which accurate (1) trigonometric parallaxes, (2) spectroscopic effective temperatures and gravities, and (3) gravitational redshifts are available. We consider these three independent constraints on mass and radius in comparison with an appropriate evolved MRR for each star. For the best-determined systems it is found that the DA white dwarfs conform to evolve theoretical MRRs at the 1{sigma} to 2{sigma} level. For the white dwarf 40 Eri B (WD 0413-077) we find strong evidence for the existence of a 'thin' hydrogen envelope. For other stars improved parallaxes will be necessary before meaningful comparisons are possible. For several systems current parallaxes approach the precision required for the state-of-the-art mass and radius determinations that will be obtained routinely from the Gaia mission. It is demonstrated here how these anticipated results can be used to firmly constrain details of theoretical mass-radius determinations.

  6. Progesterone neuroprotection in traumatic CNS injury and motoneuron degeneration.

    PubMed

    De Nicola, Alejandro F; Labombarda, Florencia; Gonzalez Deniselle, Maria Claudia; Gonzalez, Susana L; Garay, Laura; Meyer, Maria; Gargiulo, Gisella; Guennoun, Rachida; Schumacher, Michael

    2009-07-01

    Studies on the neuroprotective and promyelinating effects of progesterone in the nervous system are of great interest due to their potential clinical connotations. In peripheral neuropathies, progesterone and reduced derivatives promote remyelination, axonal regeneration and the recovery of function. In traumatic brain injury (TBI), progesterone has the ability to reduce edema and inflammatory cytokines, prevent neuronal loss and improve functional outcomes. Clinical trials have shown that short-and long-term progesterone treatment induces a significant improvement in the level of disability among patients with brain injury. In experimental spinal cord injury (SCI), molecular markers of functional motoneurons become impaired, including brain-derived neurotrophic factor (BDNF) mRNA, Na,K-ATPase mRNA, microtubule-associated protein 2 and choline acetyltransferase (ChAT). SCI also produces motoneuron chromatolysis. Progesterone treatment restores the expression of these molecules while chromatolysis subsided. SCI also causes oligodendrocyte loss and demyelination. In this case, a short progesterone treatment enhances proliferation and differentiation of oligodendrocyte progenitors into mature myelin-producing cells, whereas prolonged treatment increases a transcription factor (Olig1) needed to repair injury-induced demyelination. Progesterone neuroprotection has also been shown in motoneuron neurodegeneration. In Wobbler mice spinal cord, progesterone reverses the impaired expression of BDNF, ChAT and Na,K-ATPase, prevents vacuolar motoneuron degeneration and the development of mitochondrial abnormalities, while functionally increases muscle strength and the survival of Wobbler mice. Multiple mechanisms contribute to these progesterone effects, and the role played by classical nuclear receptors, extra nuclear receptors, membrane receptors, and the reduced metabolites of progesterone in neuroprotection and myelin formation remain an exciting field worth of exploration.

  7. Mouse models for studies of retinal degeneration and diseases

    PubMed Central

    Chang, Bo

    2013-01-01

    Summary Mouse models, with their well-developed genetics and similarity to human physiology and anatomy, serve as powerful tools with which to investigate the etiology of human retinal degeneration. Mutant mice also provide reproducible, experimental systems for elucidating pathways of normal development and function. Here, I describe the tools used in the discoveries of many retinal degeneration models, including indirect ophthalmoscopy (to look at the fundus appearance), fundus photography and fluorescein angiography (to document the fundus appearance), electroretinography (to check retinal function) as well as the heritability test (for genetic characterization). PMID:23150358

  8. Key emerging issues in progressive supranuclear palsy and corticobasal degeneration.

    PubMed

    Josephs, Keith A

    2015-03-01

    It has been approximately 50 years since neurologists were introduced to the entities, "progressive supranuclear palsy" and "corticobasal degeneration". Since the two seminal publications, there have been significant advancements in our understanding of these two neurodegenerative diseases, particularly the fact that both are associated with tau. Recent advances over the past 3 years that are notable to the field are discussed in this review that covers clinical diagnosis, pathological features, neuroimaging and CSF biomarkers, genetic associations and clinical trials related to progressive supranuclear palsy and corticobasal degeneration.

  9. Automated imaging dark adaptometer for investigating hereditary retinal degenerations

    NASA Astrophysics Data System (ADS)

    Azevedo, Dario F. G.; Cideciyan, Artur V.; Regunath, Gopalakrishnan; Jacobson, Samuel G.

    1995-05-01

    We designed and built an automated imaging dark adaptometer (AIDA) to increase accuracy, reliability, versatility and speed of dark adaptation testing in patients with hereditary retinal degenerations. AIDA increases test accuracy by imaging the ocular fundus for precise positioning of bleaching and stimulus lights. It improves test reliability by permitting continuous monitoring of patient fixation. Software control of stimulus presentation provides broad testing versatility without sacrificing speed. AIDA promises to facilitate the measurement of dark adaptation in studies of the pathophysiology of retinal degenerations and in future treatment trials of these diseases.

  10. PHOTORECEPTOR DEGENERATION IN A MOUNTAIN LION CUB (PUMA CONCOLOR).

    PubMed

    DiSalvo, Andrew R; Reilly, Christopher M; Wiggans, K Tomo; Woods, Leslie W; Wack, Ray F; Clifford, Deana L

    2016-12-01

    An orphaned 4-mo-old female mountain lion cub ( Puma concolor ) was captured along the coastline in Montaña de Oro State Park in Los Osos, California, USA. Following suspicion that the cub was visually impaired, ophthalmic examination revealed diffuse bilateral retinal atrophy. Due to a poor prognosis, humane euthanasia was elected. Necropsy and histopathological findings were consistent with photoreceptor degeneration. Based on the cub's signalment, history, and histopathology, a genetic or nutritional etiology was suspected, with the former etiology more strongly supported. To the authors' knowledge, this is the first report of photoreceptor degeneration in a wild felid and should be considered in cases of blindness.

  11. Impact of adjacent land use on coastal wetland sediments.

    PubMed

    Karstens, Svenja; Buczko, Uwe; Jurasinski, Gerald; Peticzka, Robert; Glatzel, Stephan

    2016-04-15

    Coastal wetlands link terrestrial with marine ecosystems and are influenced from both land and sea. Therefore, they are ecotones with strong biogeochemical gradients. We analyzed sediment characteristics including macronutrients (C, N, P, K, Mg, Ca, S) and heavy metals (Mn, Fe, Cu, Zn, Al, Co, Cr, Ni) of two coastal wetlands dominated by Phragmites australis at the Darss-Zingst Bodden Chain, a lagoon system at the Southern Baltic Sea, to identify the impact of adjacent land use and to distinguish between influences from land or sea. In the wetland directly adjacent to cropland (study site Dabitz) heavy metal concentrations were significantly elevated. Fertilizer application led to heavy metal accumulation in the sediments of the adjacent wetland zones. In contrast, at the other study site (Michaelsdorf), where the hinterland has been used as pasture, heavy metal concentrations were low. While the amount of macronutrients was also influenced by vegetation characteristics (e.g. carbon) or water chemistry (e.g. sulfate), the accumulation of heavy metals is regarded as purely anthropogenic influence. A principal component analysis (PCA) based on the sediment data showed that the wetland fringes of the two study sites are not distinguishable, neither in their macronutrient status nor in their concentrations of heavy metals, whereas the interior zones exhibit large differences in terms of heavy metal concentrations. This suggests that seaside influences are minor compared to influences from land. Altogether, heavy metal concentrations were still below national precautionary and action values. However, if we regard the macronutrient and heavy metal concentrations in the wetland fringes as the natural background values, an accumulation of trace elements from agricultural production in the hinterland is apparent. Thus, coastal wetlands bordering croplands may function as effective pollutant buffers today, but the future development has to be monitored closely to avoid

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

    PubMed Central

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

    2012-01-01

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

  13. CLOUD PEAK PRIMITIVE AREA AND ADJACENT AREAS, WYOMING.

    USGS Publications Warehouse

    Kiilsgaard, Thor H.; Patten, Lowell L.

    1984-01-01

    The results of a mineral survey of the Cloud Peak Primitive Area and adjacent areas in Wyoming indicated little promise for the occurrence of mineral resources. There are some prospect workings, particularly in the northern part of the area, but in none of them were there indications that ore had been mined. Samples from the workings, from nearby rocks and sediments from streams that drain the area did not yield any metal values of significance. The crystalline rocks that underlie the area do not contain oil and gas or coal, products that are extracted from the younger rocks that underlie basins on both sides of the study area.

  14. Stereoselective Organocatalytic Synthesis of Oxindoles with Adjacent Tetrasubstituted Stereocenters.

    PubMed

    Engl, Oliver D; Fritz, Sven P; Wennemers, Helma

    2015-07-06

    Oxindoles with adjacent tetrasubstituted stereocenters were obtained in high yields and stereoselectivities by organocatalyzed conjugate addition reactions of monothiomalonates (MTMs) to isatin-derived N-Cbz ketimines. The method requires only a low catalyst loading (2 mol %) and proceeds under mild reaction conditions. Both enantiomers are accessible in good yields and excellent stereoselectivities by using either Takemoto's catalyst or a cinchona alkaloid derivative. The synthetic methodology allowed establishment of a straightforward route to derivatives of the gastrin/cholecystokinin-B receptor antagonist AG-041R.

  15. Interaction of Cracks Between Two Adjacent Indents in Glass

    NASA Technical Reports Server (NTRS)

    Choi, S. R.; Salem, J. A.

    1993-01-01

    Experimental observations of the interaction behavior of cracks between two adjacent indents were made using an indentation technique in soda-lime glass. It was specifically demonstrated how one indent crack initiates and propagates in the vicinity of another indent crack. Several types of crack interactions were examined by changing the orientation and distance of one indent relative to the other. It was found that the residual stress field produced by elastic/plastic indentation has a significant influence on controlling the mode of crack interaction. The interaction of an indent crack with a free surface was also investigated for glass and ceramic specimens.

  16. Astronaut Charles Duke stands at rock adjacent to 'House Rock'

    NASA Technical Reports Server (NTRS)

    1972-01-01

    Astronaut Charles M. Duke Jr., Apollo 16 lunar module pilot, stands at a rock adjacent (south) to the huge 'House Rock' (barely out of view at right edge). Note shadow at extreme right center where the two moon-exploring crewmen of the mission sampled what they referred to as the 'eastwest split of House Rock' or the open space between this rock and 'House Rock'. Duke has a sample bag in his hand, and a lunar surface rake leans against the large boulder.

  17. Empires and percolation: stochastic merging of adjacent regions

    NASA Astrophysics Data System (ADS)

    Aldous, D. J.; Ong, J. R.; Zhou, W.

    2010-01-01

    We introduce a stochastic model in which adjacent planar regions A, B merge stochastically at some rate λ(A, B) and observe analogies with the well-studied topics of mean-field coagulation and of bond percolation. Do infinite regions appear in finite time? We give a simple condition on λ for this hegemony property to hold, and another simple condition for it to not hold, but there is a large gap between these conditions, which includes the case λ(A, B) ≡ 1. For this case, a non-rigorous analytic argument and simulations suggest hegemony.

  18. High Prevalence of Disc Degeneration and Spondylolysis in the Lumbar Spine of Professional Beach Volleyball Players

    PubMed Central

    Külling, Fabrice A.; Florianz, Hannes; Reepschläger, Bastian; Gasser, Johann; Jost, Bernhard; Lajtai, Georg

    2014-01-01

    Background: Beach volleyball is an intensive sport with high impact on the lumbar spine. Low back pain (LBP) is frequent among elite players. Increased prevalence of pathological changes on magnetic resonance imaging (MRI) in the lumbar spine of elite athletes has been reported. Hypothesis: There is an increased prevalence of disc degeneration and spondylolysis in the MRI of the lumbar spine of professional beach volleyball players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty-nine fully competitive professional male volleyball players (mean age, 28 years) completed outcomes questionnaires and underwent a complete clinical examination and an MRI of their lumbar spine. Results: Whereas 86% of players suffered from LBP during their career, the incidence of LBP in the last 4 weeks was 35%. Pain rated using a visual analog scale (VAS) averaged 3 points (range, 0-8). Twenty-three of 29 players (79%) had at least 1 degenerated disc of Pfirrmann grade ≥3. The most affected spinal levels were L4-5 in 14 (48%) and L5-S1 in 15 players (52%); both levels were involved in 5 players (17%). Six of 29 (21%) players showed a spondylolysis grade 4 according to the Hollenburg classification; there was evidence of spondylolisthesis in 2 players. There was no significant correlation between LBP and MRI abnormalities. Conclusion: In the lumbar spine MRI of professional beach volleyball players, the prevalence of disc degeneration is 79%. Spondylolysis (21%) is up to 3 times higher compared with the normal population. Abnormal MRI findings did not correlate with LBP, thus MRIs have to be interpreted with caution. PMID:26535316

  19. Squeezing properties of a two-transverse-mode degenerate optical parametric oscillator with an injected signal

    SciTech Connect

    Navarrete-Benlloch, Carlos; Roldan, Eugenio; Valcarcel, German J. de

    2011-04-15

    We study the classical and quantum properties of a degenerate optical parametric oscillator (DOPO) tuned to the first family of transverse modes at the down-converted frequency, under the injection of a resonant TEM{sub 10} mode. Unlike the usual single-mode DOPO with injected signal, large levels of squeezing are predicted even for relatively large injections. We interpret these results in connection with the spontaneous symmetry breaking predicted for this system in the absence of injection and with the existence of a bifurcation giving rise to the switching on of the (noninjected) TEM{sub 01} mode.

  20. NMNAT1 inhibits axon degeneration via blockade of SARM1-mediated NAD+ depletion

    PubMed Central

    Sasaki, Yo; Nakagawa, Takashi; Mao, Xianrong; DiAntonio, Aaron; Milbrandt, Jeffrey

    2016-01-01

    Overexpression of the NAD+ biosynthetic enzyme NMNAT1 leads to preservation of injured axons. While increased NAD+ or decreased NMN levels are thought to be critical to this process, the mechanism(s) of this axon protection remain obscure. Using steady-state and flux analysis of NAD+ metabolites in healthy and injured mouse dorsal root ganglion axons, we find that rather than altering NAD+ synthesis, NMNAT1 instead blocks the injury-induced, SARM1-dependent NAD+ consumption that is central to axon degeneration. DOI: http://dx.doi.org/10.7554/eLife.19749.001 PMID:27735788

  1. Contrast sensitivity function and mobility in elderly patients with macular degeneration.

    PubMed

    Wilcox, D T; Burdett, R

    1989-07-01

    Eleven control subjects, 64-79 years of age, and 10 subjects with macular degeneration, 70-82 years of age, were included in this study. Each participant was tested for visual acuity, spatial and temporal contrast sensitivity, and mobility in an unfamiliar environment. The course was designed with a pair of steps, ramps, and a level pathway. The subjects were timed and videotaped. The number of errors was recorded. Visual acuity and contrast sensitivity were significantly different between groups. The time to complete the course was significantly different between groups; however, the difference did not remain significant after age-adjustment.

  2. Saturation effects and inhomogeneous broadening in Doppler-free degenerate four-wave mixing

    NASA Astrophysics Data System (ADS)

    Steel, D. G.; Lam, J. F.

    1981-12-01

    We have performed experiments to study the saturation properties of degenerate four-wave mixing (DFWM) in inhomogeneously broadened material. The experiments were performed on line-center in SF 6 using a CW CO 2 laser on the P16 line at 10.6 μm. Measured peak reflectivities of 1.7 x 10 -4 are in reasonable agreement with a simple two-level model. This model also appears to correctly account for the observed saturation effects. While the material is clearly inhomogeneously broadened, both the experimental and theoretical reflectivity scale as though the material was homogeneously broadened.

  3. Cellular localization of cerebellar muscarinic receptors: an autoradiographic analysis of weaver, reeler, Purkinje cell degeneration and staggerer mice

    SciTech Connect

    Neustadt, A.; Frostholm, A.; Rotter, A.

    1988-02-01

    Light microscopic autoradiography of (/sup 3/H)quinuclidinyl benzilate binding sites was used to study the distribution of muscarinic cholinergic receptors in mouse mutants which have abnormalities affecting specific cerebellar cell types. In the normal C57BL/6J mouse, binding sites were distributed throughout the cerebellar cortex, with the highest levels in the granule cell layer and deep cerebellar nuclei. Normal binding site density was observed in the cerebellum of the weaver mutant in which the majority of granule cells had degenerated. The density of (/sup 3/H)quinuclidinyl benzilate binding sites was elevated in the cortex of the reeler, despite a reduction in the number of granule cells. The concentration of binding sites was also high over the Purkinje cell masses where granule cells were largely absent. No significant reduction in cortical (/sup 3/H)quinuclidinyl benzilate binding site density was detected in the Purkinje cell degeneration mutant, in which essentially all Purkinje cells had degenerated. In contrast, receptor binding in the deep cerebellar nuclei of this mutant was significantly increased. A substantial increase in labeling was observed in the cortex and deep nuclei of the staggerer cerebellum in which a large fraction of Golgi II cells, Purkinje cells, granule cells and mossy fibers have degenerated. We discuss the possibility that the persistence of (/sup 3/H)quinuclidinyl benzilate binding sites in all four mutants may imply a non-neuronal localization for a large proportion of muscarinic receptors in the mouse cerebellar cortex.

  4. Rimonabant, a selective cannabinoid1 receptor antagonist, protects against light-induced retinal degeneration in vitro and in vivo.

    PubMed

    Imamura, Tomoyo; Tsuruma, Kazuhiro; Inoue, Yuki; Otsuka, Tomohiro; Ohno, Yuta; Ogami, Shiho; Yamane, Shinsaku; Shimazawa, Masamitsu; Hara, Hideaki

    2017-03-16

    The endocannabinoid system is involved in some neurodegenerative diseases such as Alzheimer's disease. An endogenous constellation of proteins related to cannabinoid1 receptor signaling, including free fatty acids, diacylglycerol lipase, and N-acylethanolamine-hydrolyzing acid amidase, are localized in the murine retina. Moreover, the expression levels of endogenous agonists of cannabinoid receptors are changed in the vitreous fluid. However, the role of the endocannabinoid system in the retina, particularly in the light-induced photoreceptor degeneration, remains unknown. Therefore, we investigated involvement of the cannabinoid1 receptor in light-induced retinal degeneration using in vitro and in vivo models. To evaluate the effect of cannabinoid1 receptors in light irradiation-induced cell death, the mouse retinal cone-cell line (661W) was treated with a cannabinoid1 receptor antagonist, rimonabant. Time-dependent changes of expression and localization of retinal cannabinoid1 receptors were measured using Western blot and immunostaining. Retinal damage was induced in mice by exposure to light, followed by intravitreal injection of rimonabant. Electroretinograms and histologic analyses were performed. Rimonabant suppressed light-induced photoreceptor cell death. Cannabinoid1 receptor expression was upregulated by light exposure. Treatment with rimonabant improved both a- and b-wave amplitudes and the thickness of the outer nuclear layer. These results suggest that the cannabinoid1 receptor is involved in light-induced retinal degeneration and it may represent a therapeutic target in the light-induced photoreceptor degeneration related diseases.

  5. AAV Mediated GDNF Secretion From Retinal Glia Slows Down Retinal Degeneration in a Rat Model of Retinitis Pigmentosa

    PubMed Central

    Dalkara, Deniz; Kolstad, Kathleen D; Guerin, Karen I; Hoffmann, Natalie V; Visel, Meike; Klimczak, Ryan R; Schaffer, David V; Flannery, John G

    2011-01-01

    Mutations in over 80 identified genes can induce apoptosis in photoreceptors, resulting in blindness with a prevalence of 1 in 3,000 individuals. This broad genetic heterogeneity of disease impacting a wide range of photoreceptor functions renders the design of gene-specific therapies for photoreceptor degeneration impractical and necessitates the development of mutation-independent treatments to slow photoreceptor cell death. One promising strategy for photoreceptor neuroprotection is neurotrophin secretion from Müller cells, the primary retinal glia. Müller glia are excellent targets for secreting neurotrophins as they span the entire tissue, ensheath all neuronal populations, are numerous, and persist through retinal degeneration. We previously engineered an adeno-associated virus (AAV) variant (ShH10) capable of efficient and selective glial cell transduction through intravitreal injection. ShH10-mediated glial-derived neurotrophic factor (GDNF) secretion from glia, generates high GDNF levels in treated retinas, leading to sustained functional rescue for over 5 months. This GDNF secretion from glia following intravitreal vector administration is a safe and effective means to slow the progression of retinal degeneration in a rat model of retinitis pigmentosa (RP) and shows significant promise as a gene therapy to treat human retinal degenerations. These findings also demonstrate for the first time that glia-mediated secretion of neurotrophins is a promising treatment that may be applicable to other neurodegenerative conditions. PMID:21522134

  6. Selective rod degeneration and partial cone inactivation characterize an iodoacetic acid model of Swine retinal degeneration.

    PubMed

    Wang, Wei; Fernandez de Castro, Juan; Vukmanic, Eric; Zhou, Liang; Emery, Douglas; Demarco, Paul J; Kaplan, Henry J; Dean, Douglas C

    2011-10-07

    PURPOSE. Transgenic pigs carrying a mutant human rhodopsin transgene have been developed as a large animal model of retinitis pigmentosa (RP). This model displays some key features of human RP, but the time course of disease progression makes this model costly, time consuming, and difficult to study because of the size of the animals at end-stage disease. Here, the authors evaluate an iodoacetic acid (IAA) model of photoreceptor degeneration in the pig as an alternative model that shares features of the transgenic pig and human RP. METHODS. IAA blocks glycolysis, thereby inhibiting photoreceptor function. The effect of the intravenous injection of IAA on swine rod and cone photoreceptor viability and morphology was followed by histologic evaluation of different regions of the retina using hematoxylin and eosin and immunostaining. Rod and cone function was analyzed by full-field electroretinography and multifocal electroretinography. RESULTS. IAA led to specific loss of rods in a central-to-peripheral retinal gradient. Although cones were resistant, they showed shortened outer segments, loss of bipolar cell synaptic connections, and a diminished flicker ERG, hallmarks of transition to cone dysfunction in RP patients. CONCLUSIONS. IAA provides an alternative rod-dominant model of retinal damage that shares a surprising number of features with the pig transgenic model of RP and with human RP. This IAA model is cost-effective and rapid, ensuring that the size of the animals does not become prohibitive for end-stage evaluation or therapeutic intervention.

  7. Coexistence Analysis of Adjacent Long Term Evolution (LTE) Systems

    SciTech Connect

    Aulama, Mohannad M.; Olama, Mohammed M

    2013-01-01

    As the licensing and deployment of Long term evolution (LTE) systems are ramping up, the study of coexistence of LTE systems is an essential topic in civil and military applications. In this paper, we present a coexistence study of adjacent LTE systems aiming at evaluating the effect of inter-system interference on system capacity and performance as a function of some of the most common mitigation techniques: frequency guard band, base station (BS) antenna coupling loss, and user equipment (UE) antenna spacing. A system model is constructed for two collocated macro LTE networks. The developed model takes into consideration the RF propagation environment, power control scheme, and adjacent channel interference. Coexistence studies are performed for a different combination of time/frequency division duplex (TDD/FDD) systems under three different guard-bands of 0MHz, 5MHz, and 10MHz. Numerical results are presented to advice the minimum frequency guard band, BS coupling loss, and UE antenna isolation required for a healthy system operation.

  8. Oocyte Degeneration Associated with Follicle Cells in Female Mactra chinensis (Bivalvia: Mactridae)

    PubMed Central

    Kim, Sung Han; Chung, Ee-Yung; Lee, Ki-Young

    2014-01-01

    Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of follicle cells during oocyte degeneration are associated with phagocytosis and the intracellular digestion of products. In this study, morphologically similar degenerated phagosomes (various lysosomes), which were observed in the degenerated oocytes, appeared in the follicle cells. After the spawning of the oocytes, the follicle cells were involved in oocyte degeneration through phagocytosis by phagolysosomes. Therefore, it can be assumed that follicle cells reabsorb phagosomes from degenerated oocytes. In this study, the presence of lipid granules, which occurred from degenerating yolk granules, gradually increased in degenerating oocytes. The function of follicle cells can accumulate reserves of lipid granules and glycogen in the cytoplasm, which can be employed by the vitellogenic oocyte. Based on observations of follicle cells attached to degenerating oocytes after spawning, the follicle cells of this species are involved in the lysosomal induction of oocyte degeneration for the reabsorption of phagosomes (phagolysosomes) in the cytoplasm for nutrient storage, as seen in other bivalves. PMID:25949203

  9. Proton Beam Therapy for Hepatocellular Carcinoma Adjacent to the Porta Hepatis

    SciTech Connect

    Mizumoto, Masashi; Tokuuye, Koichi Sugahara, Shinji; Nakayama, Hidetsugu; Fukumitsu, Nobuyoshi; Ohara, Kiyoshi; Abei, Masato; Shoda, Junichi; Tohno, Eriko; Minami, Manabu

    2008-06-01

    Purpose: To evaluate the efficacy and safety of proton beam therapy (PBT) for patients with hepatocellular carcinoma (HCC) located adjacent to the porta hepatis. Methods and Materials: Subjects of the study were 53 patients with HCC located within 2 cm of the main portal vein. All patients had tumor confined to the radiation field with no evidence of metastatic disease. All patients had hepatic function levels of a Child-Pugh score of 10 or less, Eastern Cooperative Oncology Group performance status of 2 or less, and no uncontrolled ascites. Patients underwent PBT of 72.6 GyE in 22 fractions from Sept 2001 to Dec 2004. Results: After 3 years, the actuarial survival rate was 45.1% and local control rate was 86.0%. Prognostic factors for survival included Child-Pugh score, number of tumors, and {alpha}-fetoprotein levels. No late treatment-related toxicity of Grade 2 or higher was observed. Conclusions: The PBT delivering 72.6 GyE in 22 fractions appears to be effective and safe for HCC adjacent to the porta hepatis.

  10. Multiscale bi-Gaussian filter for adjacent curvilinear structures detection with application to vasculature images.

    PubMed

    Xiao, Changyan; Staring, Marius; Wang, Yaonan; Shamonin, Denis P; Stoel, Berend C

    2013-01-01

    The intensity or gray-level derivatives have been widely used in image segmentation and enhancement. Conventional derivative filters often suffer from an undesired merging of adjacent objects because of their intrinsic usage of an inappropriately broad Gaussian kernel; as a result, neighboring structures cannot be properly resolved. To avoid this problem, we propose to replace the low-level Gaussian kernel with a bi-Gaussian function, which allows independent selection of scales in the foreground and background. By selecting a narrow neighborhood for the background with regard to the foreground, the proposed method will reduce interference from adjacent objects simultaneously preserving the ability of intraregion smoothing. Our idea is inspired by a comparative analysis of existing line filters, in which several traditional methods, including the vesselness, gradient flux, and medialness models, are integrated into a uniform framework. The comparison subsequently aids in understanding the principles of different filtering kernels, which is also a contribution of this paper. Based on some axiomatic scale-space assumptions, the full representation of our bi-Gaussian kernel is deduced. The popular γ-normalization scheme for multiscale integration is extended to the bi-Gaussian operators. Finally, combined with a parameter-free shape estimation scheme, a derivative filter is developed for the typical applications of curvilinear structure detection and vasculature image enhancement. It is verified in experiments using synthetic and real data that the proposed method outperforms several conventional filters in separating closely located objects and being robust to noise.

  11. Prevalence and Abundance of Florfenicol and Linezolid Resistance Genes in Soils Adjacent to Swine Feedlots

    PubMed Central

    Zhao, Qin; Wang, Yang; Wang, Shaolin; Wang, Zheng; Du, Xiang-dang; Jiang, Haiyang; Xia, Xi; Shen, Zhangqi; Ding, Shuangyang; Wu, Congming; Zhou, Bingrui; Wu, Yongning; Shen, Jianzhong

    2016-01-01

    Florfenicol is extensively used in livestock to prevent or cure bacterial infections. However, it is not known whether the administration of florfenicol has resulted in the emergence and dissemination of florfenicol resistance genes (FRGs, including fexA, fexB, cfr, optrA, floR, and pexA) in microbial populations in surrounding farm environments. Here we collected soil samples for the detection of FRGs and the residue of florfenicol from six swine farms with the record of florfenicol usage. Quantitative polymerase chain reaction and metagenomic sequencing revealed a significantly higher relative abundance of FRGs in the soils adjacent to the three swine farms where florfenicol was heavily used compared with the other sites. Meanwhile, the detectable levels of florfenicol were also identified in soils from two of these three farms using ultra-performance liquid chromatography tandem mass spectrometry. It appears that amount of florfenicol used on swine farms and the spreading of soils with swine waste could promote the prevalence and abundance of FRGs, including the linezolid resistance genes cfr and optrA, in adjacent soils, and agricultural application of swine manure with florfenicol may have caused a residual level of florfenicol in the soils. PMID:27573068

  12. Biological treatment strategies for disc degeneration: potentials and shortcomings

    PubMed Central

    Nerlich, Andreas G.; Boos, Norbert

    2006-01-01

    Recent advances in molecular biology, cell biology and material sciences have opened a new emerging field of techniques for the treatment of musculoskeletal disorders. These new treatment modalities aim for biological repair of the affected tissues by introducing cell-based tissue replacements, genetic modifications of resident cells or a combination thereof. So far, these techniques have been successfully applied to various tissues such as bone and cartilage. However, application of these treatment modalities to cure intervertebral disc degeneration is in its very early stages and mostly limited to experimental studies in vitro or in animal studies. We will discuss the potential and possible shortcomings of current approaches to biologically cure disc degeneration by gene therapy or tissue engineering. Despite the increasing number of studies examining the therapeutic potential of biological treatment strategies, a practicable solution to routinely cure disc degeneration might not be available in the near future. However, knowledge gained from these attempts might be applied in a foreseeable future to cure the low back pain that often accompanies disc degeneration and therefore be beneficial for the patient. PMID:16983559

  13. Advancing Research and Treatment for Frontotemporal Lobar Degeneration (ARTFL)

    ClinicalTrials.gov

    2017-03-01

    FTLD; Progressive Supranuclear Palsy (PSP); Frontotemporal Dementia (FTD); Corticobasal Degeneration (CBD); PPA Syndrome; Behavioral Variant Frontotemporal Dementia (bvFTD); Semantic Variant Primary Progressive Aphasia (svPPA); Nonfluent Variant Primary Progressive Aphasia (nfvPPA); FTD With Amyotrophic Lateral Sclerosis (FTD/ALS); Amyotrophic Lateral Sclerosis (ALS); Oligosymptomatic PSP (oPSP); Corticobasal Syndrome (CBS)

  14. Gestural Imitation and Limb Apraxia in Corticobasal Degeneration

    ERIC Educational Resources Information Center

    Salter, Jennifer E.; Roy, Eric A.; Black, Sandra E.; Joshi, Anish; Almeida, Quincy

    2004-01-01

    Limb apraxia is a common symptom of corticobasal degeneration (CBD). While previous research has shown that individuals with CBD have difficulty imitating transitive (tool-use actions) and intransitive non-representational gestures (nonsense actions), intransitive representational gestures (actions without a tool) have not been examined. In the…

  15. Nutritional modulation of age-related macular degeneration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly worldwide. It affects 30-50 million individuals and clinical hallmarks of AMD are observed in at least one third of persons over the age of 75 in industrialized countries (Gehrs et al., 2006). Costs associated wi...

  16. Global existence for a degenerate haptotaxis model of cancer invasion

    NASA Astrophysics Data System (ADS)

    Zhigun, Anna; Surulescu, Christina; Uatay, Aydar

    2016-12-01

    We propose and study a strongly coupled PDE-ODE system with tissue-dependent degenerate diffusion and haptotaxis that can serve as a model prototype for cancer cell invasion through the extracellular matrix. We prove the global existence of weak solutions and illustrate the model behavior by numerical simulations for a two-dimensional setting.

  17. A geometrical approach to degenerate scalar-tensor theories

    NASA Astrophysics Data System (ADS)

    Chagoya, Javier; Tasinato, Gianmassimo

    2017-02-01

    Degenerate scalar-tensor theories are recently proposed covariant theories of gravity coupled with a scalar field. Despite being characterised by higher order equations of motion, they do not propagate more than three degrees of freedom, thanks to the existence of constraints. We discuss a geometrical approach to degenerate scalar-tensor systems, and analyse its consequences. We show that some of these theories emerge as a certain limit of DBI Galileons. In absence of dynamical gravity, these systems correspond to scalar theories enjoying a symmetry which is different from Galileon invariance. The scalar theories have however problems concerning the propagation of fluctuations around a time dependent background. These issues can be tamed by breaking the symmetry by hand, or by minimally coupling the scalar with dynamical gravity in a way that leads to degenerate scalar-tensor systems. We show that distinct theories can be connected by a relation which generalizes Galileon duality, in certain cases also when gravity is dynamical. We discuss some implications of our results in concrete examples. Our findings can be helpful for assessing stability properties and understanding the non-perturbative structure of systems based on degenerate scalar-tensor systems.

  18. Speech and Language Findings Associated with Paraneoplastic Cerebellar Degeneration

    ERIC Educational Resources Information Center

    Paslawski, Teresa; Duffy, Joseph R.; Vernino, Steven

    2005-01-01

    Paraneoplastic cerebellar degeneration (PCD) is an autoimmune disease that can be associated with cancer of the breast, lung, and ovary. The clinical presentation of PCD commonly includes ataxia, visual disturbances, and dysarthria. The speech disturbances associated with PCD have not been well characterized, despite general acceptance that…

  19. Exact null controllability of degenerate evolution equations with scalar control

    SciTech Connect

    Fedorov, Vladimir E; Shklyar, Benzion

    2012-12-31

    Necessary and sufficient conditions for the exact null controllability of a degenerate linear evolution equation with scalar control are obtained. These general results are used to examine the exact null controllability of the Dzektser equation in the theory of seepage. Bibliography: 13 titles.

  20. Anisotropic uniqueness classes for a degenerate parabolic equation

    SciTech Connect

    Vil'danova, V F; Mukminov, F Kh

    2013-11-30

    Anisotropic uniqueness classes of Tacklind type are identified for a degenerate linear parabolic equation of the second order in an unbounded domain. The Cauchy problem and mixed problems with boundary conditions of the first and third type are considered. Bibliography: 18 titles.