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Sample records for small nerve fibers

  1. Membrane properties in small cutaneous nerve fibers in humans.

    Science.gov (United States)

    Hennings, Kristian; Frahm, Ken Steffen; Petrini, Laura; Andersen, Ole K; Arendt-Nielsen, Lars; Mørch, Carsten D

    2017-02-01

    Assessment of membrane properties is important for understanding the mechanisms of painful peripheral neuropathy, developing new diagnostic techniques, and screening/profiling of analgesics that target ion channels. Small cutaneous nerves were activated electrically by small diameter (0.2 mm) cathodes, and large nerves were activated by ordinary patch electrodes. This new perception threshold tracking method combines perception threshold assessment and stimulation paradigms from conventional threshold tracking. The strength-duration time-constant of large fibers (580 µs ± 160 µs) was lower than the time constant of small fibers (1060 µs ± 690 µs; P fibers showed less threshold reduction than large fibers (repeated-measures analysis of variance, Bonferroni, P = 0.006). This is a reliable method to investigate the membrane properties of small cutaneous nerve fibers in humans and may be used in clinical settings as a diagnostic or profiling tool. Muscle Nerve 55: 195-201, 2017. © 2016 Wiley Periodicals, Inc.

  2. Small nerve fiber involvement is frequent in X-linked adrenoleukodystrophy.

    Science.gov (United States)

    Horn, Morten A; Nilsen, Kristian B; Jørum, Ellen; Mellgren, Svein I; Tallaksen, Chantal M E

    2014-05-13

    To investigate the presence of small nerve fiber dysfunction in subjects with X-linked adrenoleukodystrophy. Cross-sectional study in which 11 Norwegian subjects (3 males, 8 females) with X-linked adrenoleukodystrophy, phenotypes ranging from asymptomatic to wheelchair-bound with adrenomyeloneuropathy, were investigated with neurophysiologic studies including EMG, nerve conduction velocities, quantitative sensory testing, tests of autonomic function, and skin biopsy for intraepidermal nerve fiber density measurements. We found small nerve fiber dysfunction in 10 of 11 subjects, increasing with age and more pronounced in males. Low intraepidermal nerve fiber densities were found in 5 of 11 subjects, indicating a loss of thin unmyelinated nerve fibers peripherally. Five of 11 subjects showed small nerve fiber dysfunction despite normal nerve fiber densities, suggesting possible involvement of the spinothalamic tracts. Two subjects showed moderate abnormalities in autonomic function tests. Evidence of small nerve fiber dysfunction was widespread in this cohort of subjects with X-linked adrenoleukodystrophy, with findings indicating loss of peripheral small nerve fibers and possibly also fibers of the spinothalamic tracts. The results support the theory of primary axonal degeneration in adrenomyeloneuropathy. Evidence of nervous system involvement was found in all heterozygotes, with severity increasing with age. Clinicians caring for these patients should be alert to signs of small nerve fiber involvement.

  3. Biological conduit small gap sleeve bridging method for peripheral nerve injury: regeneration law of nerve fibers in the conduit

    Directory of Open Access Journals (Sweden)

    Pei-xun Zhang

    2015-01-01

    Full Text Available The clinical effects of 2-mm small gap sleeve bridging of the biological conduit to repair peripheral nerve injury are better than in the traditional epineurium suture, so it is possible to replace the epineurium suture in the treatment of peripheral nerve injury. This study sought to identify the regeneration law of nerve fibers in the biological conduit. A nerve regeneration chamber was constructed in models of sciatic nerve injury using 2-mm small gap sleeve bridging of a biodegradable biological conduit. The results showed that the biological conduit had good histocompatibility. Tissue and cell apoptosis in the conduit apparently lessened, and regenerating nerve fibers were common. The degeneration regeneration law of Schwann cells and axons in the conduit was quite different from that in traditional epineurium suture. During the prime period for nerve fiber regeneration (2-8 weeks, the number of Schwann cells and nerve fibers was higher in both proximal and distal ends, and the effects of the small gap sleeve bridging method were better than those of the traditional epineurium suture. The above results provide an objective and reliable theoretical basis for the clinical application of the biological conduit small gap sleeve bridging method to repair peripheral nerve injury.

  4. Treatment of a patient with small fiber pathology using nerve biopsy and grafting: a case report.

    Science.gov (United States)

    Peled, Ziv M

    2013-10-01

    Small fiber pathology is a common clinical entity with a variable clinical presentation and etiology. Unfortunately, little has been described regarding its treatment because a majority of cases are idiopathic. Hence, treatment often consists of symptomatic management of pain and autonomic dysfunction. This report describes a patient who was presented with an undiagnosed pain syndrome thought to be affecting nerves within both lower extremities and causing significant pain. A sural nerve biopsy was performed for diagnostic purposes and nerve repair was performed using Avance nerve allograft (AxoGen Inc., Alachua, FL). Light microscopic evaluation was unremarkable, but electron microscopy revealed small fiber pathology. Postoperatively, the patient experienced a complete resolution of her pain on the involved extremity. These results suggest a potential, novel approach for treatment of such cases and possible mechanisms for the patient's clinical improvement are explored. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Reduced intraepidermal nerve fiber density after a sustained increase in insular glutamate: a proof-of-concept study examining the pathogenesis of small fiber pathology in fibromyalgia

    Directory of Open Access Journals (Sweden)

    Steven E. Harte

    2017-06-01

    Conclusion:. Bilateral insular PDC administration produced a persistent increase in multimodal pain behaviors and a decrease in peripheral nerve fibers in rat. These preclinical findings offer preliminary support that insular hyperactivity may be a casual factor in the development of small fiber pathology in FM.

  6. Signal propagation in nerve fiber

    Science.gov (United States)

    Zayko, Yuriy N.

    2007-05-01

    In this paper the problem of signal propagation in nerve fiber is considered. Ohm losses and heat processes were taken into account. These permit to combine the two stages (metabolic and non-metabolic) of propagation and Na + and K + ions transmission through cell membrane due propagation. Electrodynamics of nerve fiber with losses is described by telegraph equations. Heat processes in fiber are described by an equation of entropy transfer. Ion motion at metabolic stage against the electro-chemical potential is described by negative conductance, responsible for the escape flow. The running- wave-type solutions of these equations are studied. An integral and an explicit solution of the given system are obtained. The solution represented by a series of quasi-harmonic pulses is investigated numerically. This proves the applicability of telegraph equation to the problem considered. Different types of solitary waves corresponding to various types of conductivity are also investigated.

  7. The function of sensory nerve fibers in lumbar radiculopathy. Use of quantitative sensory testing in the exploration of different populations of nerve fibers and dermatomes.

    Science.gov (United States)

    Nygaard, O P; Mellgren, S I

    1998-02-01

    The function of sensory nerve fibers in patients with lumbar radiculopathy and in control individuals was evaluated using quantitative sensory testing. To investigate the effect of lumbar nerve root compression on different populations of nerve fibers and to explore the function of sensory nerve fibers in neighboring nerve roots not involved in the mechanical compression. Results from experimental and clinical studies indicate that chronic compression of lumbar nerve roots affects the large myelinated nerve fibers. The majority of nerve fibers involved in the sensation of pain, however, are small afferent nerve fibers. It is therefore of interest to study the effect of compression on large and small sensory afferent channels. Several authors have elucidated the biochemical interaction between disc tissue and nerve roots. Chemical substances in the epidural space can reach the nerve fibers in nerve roots at the same or neighboring lumbar segments. In this way, fibers not involved in the mechanical compression may be affected. The small nerve fibers were studied using tests for thermal thresholds (thermotest), and the large myelinated fibers were studied by vibrametry. Forty-two patients were investigated in the symptomatic and the asymptomatic leg, and the results were compared with those of 21 healthy individuals. The thresholds of cold, warmth, and vibration were significantly increased in the dermatome of the compressed nerve root, indicating that large and small sensory nerve fibers were affected. Further, the thresholds were significantly increased in the neighboring dermatomes in the symptomatic and the asymptomatic leg. Large and small sensory afferent nerve fibers are affected in lumbar radiculopathy. The increase in sensation thresholds in the ipsilateral neighboring dermatome and in the dermatomes in the asymptomatic leg indicates that adjacent nerve roots are involved in the pathophysiology of sciatica in patients with lumbar disc herniation.

  8. Ephaptic coupling of myelinated nerve fibers

    DEFF Research Database (Denmark)

    Binczak, S.; Eilbeck, J. C.; Scott, Alwyn C.

    2001-01-01

    Numerical predictions of a simple myelinated nerve fiber model are compared with theoretical results in the continuum and discrete limits, clarifying the nature of the conduction process on an isolated nerve axon. Since myelinated nerve fibers are often arranged in bundles, this model is used...... to study ephaptic (nonsynaptic) interactions between impulses on parallel fibers, which may play a functional role in neural processing. (C) 2001 Published by Elsevier Science B.V....

  9. Sympathetic Nerve Fibers in Human Cervical and Thoracic Vagus Nerves

    Science.gov (United States)

    Seki, Atsuko; Green, Hunter R.; Lee, Thomas D.; Hong, LongSheng; Tan, Jian; Vinters, Harry V.; Chen, Peng-Sheng; Fishbein, Michael C.

    2014-01-01

    Background Vagus nerve stimulation therapy (VNS) has been used for chronic heart failure (CHF), and is believed to improve imbalance of autonomic control by increasing parasympathetic activity. Although it is known that there is neural communication between the VN and the cervical sympathetic trunk, there are few data regarding the quantity and/or distribution of the sympathetic components within the VN. Objective To examine the sympathetic component within human VN and correlate these with the presence of cardiac and neurologic diseases. Methods We performed immunohistochemistry on 31 human cervical and thoracic VNs (total 104 VNs) from autopsies and we reviewed the patients’ records. We correlated the quantity of sympathetic nerve fibers within the VNs with cardiovascular and neurologic disease states. Results All 104 VNs contain TH positive (sympathetic) nerve fibers; the mean TH positive areas were 5.47% in right cervical, 3.97% in left cervical, 5.11% in right thoracic, and 4.20% in left thoracic VN. The distribution of TH positive nerve fibers varied from case to case: central, peripheral, or scattered throughout nerve bundles. No statistically significant differences in nerve morphology were seen between diseases in which VNS is considered effective (depression and CHF), and other cardiovascular diseases, or neurodegenerative disease. Conclusion Human VNs contain sympathetic nerve fibers. The sympathetic component within the VN could play a role in physiologic effects reported with VNS. The recognition of sympathetic nerve fibers in the VNs may lead to better understanding of the therapeutic mechanisms of VNS. PMID:24768897

  10. Sensation, mechanoreceptor, and nerve fiber function after nerve regeneration.

    Science.gov (United States)

    Krarup, Christian; Rosén, Birgitta; Boeckstyns, Michel; Ibsen Sørensen, Allan; Lundborg, Göran; Moldovan, Mihai; Archibald, Simon J

    2017-12-01

    Sensation is essential for recovery after peripheral nerve injury. However, the relationship between sensory modalities and function of regenerated fibers is uncertain. We have investigated the relationships between touch threshold, tactile gnosis, and mechanoreceptor and sensory fiber function after nerve regeneration. Twenty-one median or ulnar nerve lesions were repaired by a collagen nerve conduit or direct suture. Quantitative sensory hand function and sensory conduction studies by near-nerve technique, including tactile stimulation of mechanoreceptors, were followed for 2 years, and results were compared to noninjured hands. At both repair methods, touch thresholds at the finger tips recovered to 81 ± 3% and tactile gnosis only to 20 ± 4% (p function of regenerated peripheral nerve fibers and reinnervated mechanoreceptors may differentially influence recovery of sensory modalities. Touch was affected by the number and function of regenerated fibers and mechanoreceptors. In contrast, tactile gnosis depends on the input and plasticity of the central nervous system (CNS), which may explain the absence of a direct relation between electrophysiological parameters and poor recovery. Dispersed maturation of sensory nerve fibers with desynchronized inputs to the CNS also contributes to the poor recovery of tactile gnosis. Ann Neurol 2017. Ann Neurol 2017;82:940-950. © 2017 American Neurological Association.

  11. The Bushbaby Optic Nerve: Fiber Count and Fiber Diameter Spectrum

    Science.gov (United States)

    1986-03-01

    The identification of unmyelinated axons was based primariliy on the shape or the axon, its membrane thickness, and the axoplasmic contents ( Maturana ...studies of the optic nerve that axons are not rigid, circular tubes ( Maturana , 1959). They do not traverse the length of the optic nerve in register...fascicles as in most vertebrates (turtle: Fulbrook and Granda, 1978; pigeon: Binggelli and Paule, 1969; frog: Maturana , 1959). Nerve Fiber Total Counts

  12. [Small fiber neuropathy].

    Science.gov (United States)

    Langlois, V; Bedat Millet, A-L; Lebesnerais, M; Miranda, S; Marguet, F; Benhamou, Y; Marcorelles, P; Lévesque, H

    2017-04-11

    Small fiber neuropathy (SFN) is still unknown. Characterised by neuropathic pain, it typically begins by burning feet, but could take many other expression. SFN affects the thinly myelinated Aδ and unmyelinated C-fibers, by an inherited or acquired mechanism, which could lead to paresthesia, thermoalgic disorder or autonomic dysfunction. Recent studies suggest the preponderant role of ion channels such as Nav1.7. Furthermore, erythromelalgia or burning mouth syndrome are now recognized as real SFN. Various aetiologies of SFN are described. It could be isolated or associated with diabetes, impaired glucose metabolism, vitamin deficiency, alcohol, auto-immune disease, sarcoidosis etc. Several mutations have recently been identified, like Nav1.7 channel leading to channelopathies. Diagnostic management is based primarily on clinical examination and demonstration of small fiber dysfunction. Laser evoked potentials, Sudoscan®, cutaneous biopsy are the main test, but had a difficult access. Treatment is based on multidisciplinary management, combining symptomatic treatment, psychological management and treatment of an associated etiology. Copyright © 2017 Société Nationale Française de Médecine Interne (SNFMI). Published by Elsevier SAS. All rights reserved.

  13. Unmyelinated nerve fiber degeneration in chronic inflammatory demyelinating polyneuropathy

    NARCIS (Netherlands)

    Bosboom, WMJ; Van den Berg, LH; Dieks, HJG; Plante, E; Veldman, H; Franssen, H; Wokke, JHJ

    To determine whether unmyelinated nerve fibers escape degeneration as one might expect in an immune response exclusively directed at myelin, we performed a morphometric examination of unmyelinated axons and myelinated nerve fibers in sural nerve biopsy specimens of 14 patients with a chronic

  14. Nerve Fibers in Breast Cancer Tissues Indicate Aggressive Tumor Progression

    OpenAIRE

    Huang, Di; Su, Shicheng; Cui, Xiuying; Shen, Ximing; Zeng, Yunjie; Wu, Wei; Chen, Jianing; Chen, Fei; He, Chonghua; Liu, Jiang; Huang, Wei; Liu, Qiang; Su, Fengxi; Song, Erwei; Ouyang, Nengtai

    2014-01-01

    Abstract Emerging evidence has indicated nerve fibers as a marker in the progression of various types of cancers, such as pancreatic cancer and prostate cancer. However, whether nerve fibers are associated with breast cancer progression remains unclear. In this study, we evaluated the presence of nerve fibers in 352 breast cancer specimens and 83 benign breast tissue specimens including 43 cases of cystic fibrosis and 40 cases of fibroadenoma from 2 independent breast tumor center using immun...

  15. Nerve fibers in breast cancer tissues indicate aggressive tumor progression.

    Science.gov (United States)

    Huang, Di; Su, Shicheng; Cui, Xiuying; Shen, Ximing; Zeng, Yunjie; Wu, Wei; Chen, Jianing; Chen, Fei; He, Chonghua; Liu, Jiang; Huang, Wei; Liu, Qiang; Su, Fengxi; Song, Erwei; Ouyang, Nengtai

    2014-12-01

    Emerging evidence has indicated nerve fibers as a marker in the progression of various types of cancers, such as pancreatic cancer and prostate cancer. However, whether nerve fibers are associated with breast cancer progression remains unclear. In this study, we evaluated the presence of nerve fibers in 352 breast cancer specimens and 83 benign breast tissue specimens including 43 cases of cystic fibrosis and 40 cases of fibroadenoma from 2 independent breast tumor center using immunohistochemical staining for specific peripheral nerve fiber markers.In all, nerve fibers were present in 130 out of 352 breast cancer tissue specimens, while none were detected in normal breast tissue specimens. Among 352 cases, we defined 239 cases from Sun Yat-Sen Memorial Hospital, Guangzhou, China, as the training set, and 113 cases from the First Affiliated Hospital of Shantou University, Guangdong, China, as the validation set. The thickness of tumor-involving nerve fibers is significantly correlated with poor differentiation, lymph node metastasis, high clinical staging, and triple negative subtype in breast cancer. More importantly, Cox multifactor analysis indicates that the thickness of tumor-involving nerve fibers is a previously unappreciated independent prognostic factors associated with shorter disease-free survival of breast cancer patients. Our findings are further validated by online Oncomine database. In conclusion, our results show that nerve fiber involvement in breast cancer is associated with progression of the malignancy and warrant further studies in the future.

  16. Nerve Fibers in Breast Cancer Tissues Indicate Aggressive Tumor Progression

    Science.gov (United States)

    Huang, Di; Su, Shicheng; Cui, Xiuying; Shen, Ximing; Zeng, Yunjie; Wu, Wei; Chen, Jianing; Chen, Fei; He, Chonghua; Liu, Jiang; Huang, Wei; Liu, Qiang; Su, Fengxi; Song, Erwei; Ouyang, Nengtai

    2014-01-01

    Abstract Emerging evidence has indicated nerve fibers as a marker in the progression of various types of cancers, such as pancreatic cancer and prostate cancer. However, whether nerve fibers are associated with breast cancer progression remains unclear. In this study, we evaluated the presence of nerve fibers in 352 breast cancer specimens and 83 benign breast tissue specimens including 43 cases of cystic fibrosis and 40 cases of fibroadenoma from 2 independent breast tumor center using immunohistochemical staining for specific peripheral nerve fiber markers. In all, nerve fibers were present in 130 out of 352 breast cancer tissue specimens, while none were detected in normal breast tissue specimens. Among 352 cases, we defined 239 cases from Sun Yat-Sen Memorial Hospital, Guangzhou, China, as the training set, and 113 cases from the First Affiliated Hospital of Shantou University, Guangdong, China, as the validation set. The thickness of tumor-involving nerve fibers is significantly correlated with poor differentiation, lymph node metastasis, high clinical staging, and triple negative subtype in breast cancer. More importantly, Cox multifactor analysis indicates that the thickness of tumor-involving nerve fibers is a previously unappreciated independent prognostic factors associated with shorter disease-free survival of breast cancer patients. Our findings are further validated by online Oncomine database. In conclusion, our results show that nerve fiber involvement in breast cancer is associated with progression of the malignancy and warrant further studies in the future. PMID:25501061

  17. Cornea nerve fiber quantification and construction of phenotypes in patients with fibromyalgia.

    Science.gov (United States)

    Oudejans, Linda; He, Xuan; Niesters, Marieke; Dahan, Albert; Brines, Michael; van Velzen, Monique

    2016-03-23

    Cornea confocal microscopy (CCM) is a novel non-invasive method to detect small nerve fiber pathology. CCM generally correlates with outcomes of skin biopsies in patients with small fiber pathology. The aim of this study was to quantify the morphology of small nerve fibers of the cornea of patients with fibromyalgia in terms of density, length and branching and further phenotype these patients using standardized quantitative sensory testing (QST). Small fiber pathology was detected in the cornea of 51% of patients: nerve fiber length was significantly decreased in 44% of patients compared to age- and sex-matched reference values; nerve fiber density and branching were significantly decreased in 10% and 28% of patients. The combination of the CCM parameters and sensory tests for central sensitization, (cold pain threshold, mechanical pain threshold, mechanical pain sensitivity, allodynia and/or windup), yielded four phenotypes of fibromyalgia patients in a subgroup analysis: one group with normal cornea morphology without and with signs of central sensitization, and a group with abnormal cornea morphology parameters without and with signs of central sensitization. In conclusion, half of the tested fibromyalgia population demonstrates signs of small fiber pathology as measured by CCM. The four distinct phenotypes suggest possible differences in disease mechanisms and may require different treatment approaches.

  18. Retinal peripapillary nerve fiber layer thickness in neuromyelitis optica.

    Science.gov (United States)

    Merle, Harold; Olindo, Stéphane; Donnio, Angélique; Richer, Raymond; Smadja, Didier; Cabre, Philippe

    2008-10-01

    To measure the thickness of retinal peripapillary nerve fibers throughout the course of neuromyelitis optica (NMO). This study was of a cross-sectional design, examining the thickness of the retinal peripapillary nerve fiber layer by optical coherence tomography, in patients with NMO (n = 15; 30 eyes), patients with multiple sclerosis (MS; n = 15; 30 eyes), and a control group (n = 23; 46 eyes). The thicknesses were acquired according to protocol with the fast RNFL (Retinal Nerve Fiber Layer) procedure. The study of visual function includes for each eye a determination of refraction, measurement of visual acuity, measurement of contrast vision, an analysis of color vision, and a frequency-doubling technology perimetry (FDTP). The main outcome measurements were the thickness of the retinal peripapillary nerve fibers, visual acuity, and scores of contrast vision. The average thickness of retinal peripapillary nerve fibers was respectively in the NMO, MS, and control group: 65.44 +/- 24.19, 83.85 +/- 24.12, and 106.24 +/- 12.46 microm (P = 0.01). The average thickness of retinal peripapillary nerve fibers correlated to visual acuity, the scores of contrast vision, the scores of FDTP, and the number of episodes per patient (r = -0.58, P = 0.03). This is the first study to produce measurements of the thickness of retinal peripapillary nerve fibers during optic neuropathies of NMO. The optic neuropathies of NMO are also accompanied by an acute and chronic axonal loss, as clearly illustrated by the OCT.

  19. Small Business Innovations (Fiber Optics)

    Science.gov (United States)

    1991-01-01

    Foster-Miller, Inc. Waltham, MA developed the In-Situ Fiber Optic Polymer Reaction Monitor which could lead to higher yields and lower costs in complex composite manufacturing. The monitor, developed under a Small Business Innovation Research (SBIR) contract with Langley Research Center, uses an infrared, fiber optic sensor to track the molecular vibrational characteristics of a composite part while it is being cured. It is the first analytical system capable of directly measuring the chemistry of advanced composite materials.

  20. Calculation of action potential propagation in nerve fiber.

    Science.gov (United States)

    Bogatov, N M; Grigoryan, L R; Ponetaeva, E G; Sinisyn, A S

    2014-05-01

    This article introduces generalization of the action potential spreading model which considers generation of the action potential in each segment of the nerve fiber. Behavior of the impulse signal waveform during the propagation process was analyzed. A mechanism of distributed generation of the charge in nerve fiber results in decrease of phase velocity of signal spreading rate. Amplitude of the action potential decreases and pulse width increases in the action potential propagation process. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Morphometric analysis of the diameter and g-ratio of the myelinated nerve fibers of the human sciatic nerve during the aging process.

    Science.gov (United States)

    Ugrenović, Sladjana; Jovanović, Ivan; Vasović, Ljiljana; Kundalić, Braca; Čukuranović, Rade; Stefanović, Vladisav

    2016-06-01

    Myelinated nerve fibers suffer from different degrees of atrophy with age. The success of subsequent regeneration varies. The aim of this research was to analyze myelinated fibers of the human sciatic nerve during the aging process. Morphometric analysis was performed on 17 cases with an age range from 9 to 93 years. The outer and inner diameter of 100 randomly selected nerve fibers was measured in each of the cases evaluated, and the g-ratio (axonal diameter/outer diameter of the whole nerve fiber) of each was calculated. Scatter plots of the diameters and g-ratios of the analyzed fibers were then analyzed. Nerve fibers of each case were classified into three groups according to the g-ratio values: group I (g-ratio lower than 0.6), group II (g-ratio from 0.6 to 0.7) and group III (g-ratio higher than 0.7). Afterwards, nerve fibers of group II were further classified into small and large subgroups. The percentages of each group of nerve fibers were computed for each case and these values were used for correlational and bivariate linear regression analysis. The percentage of myelinated nerve fibers with large diameter and optimal g-ratio of the sciatic nerve declines significantly with age. This is accompanied by a simultaneous significant increase in the percentage of small myelinated fibers with g-ratio values close to 1 that occupy the upper left quadrant of the scatter plot. It can be concluded that aging of the sciatic nerve is associated with significant atrophy of large myelinated fibers. Additionally, a significant increase in regenerated nerve fibers with thinner myelin sheath is observed with age, which, together with the large myelinated fiber atrophy, might be the cause of the age-related decline in conduction velocity. A better understanding of the changes in aging peripheral nerves might improve interpretation of their pathological changes, as well as comprehension of their regeneration in individuals of different age.

  2. Morphological and neurochemical differences in peptidergic nerve fibers of the mouse vagina.

    Science.gov (United States)

    Barry, Christine M; Ji, Esther; Sharma, Harman; Beukes, Lara; Vilimas, Patricia I; DeGraaf, Yvette C; Matusica, Dusan; Haberberger, Rainer V

    2017-07-01

    The vagina is innervated by a complex arrangement of sensory, sympathetic, and parasympathetic nerve fibers that contain classical transmitters plus an array of neuropeptides and enzymes known to regulate diverse processes including blood flow and nociception. The neurochemical characteristics and distributions of peptide-containing nerves in the mouse vagina are unknown. This study used multiple labeling immunohistochemistry, confocal maging and analysis to investigate the presence and colocalization of the peptides vasoactive intestinal polypeptide (VIP), calcitonin-gene related peptide (CGRP), substance P (SP), neuropeptide tyrosine (NPY), and the nitric oxide synthesizing enzyme neuronal nitric oxide synthase (nNOS) in nerve fibers of the murine vaginal wall. We compared cervical and vulvar areas of the vagina in young nullipara and older multipara C57Bl/6 mice, and identified differences including that small ganglia were restricted to cervical segments, epithelial fibers were mainly present in vulvar segments and most nerve fibers were found in the lamina propria of the cervical region of the vagina, where a higher number of fibers containing immunoreactivity for VIP, CGRP, SP, or nNOS were found. Two populations of VIP-containing fibers were identified: fibers containing CGRP and fibers containing VIP but not CGRP. Differences between young and older mice were present in multiple layers of the vaginal wall, with older mice showing overall loss of innervation of epithelium of the proximal vagina and reduced proportions of VIP, CGRP, and SP containing nerve fibers in the distal epithelium. The distal vagina also showed increased vascularization and perivascular fibers containing NPY. Immunolabeling of ganglia associated with the vagina indicated the likely origin of some peptidergic fibers. Our results reveal regional differences and age- or parity-related changes in innervation of the mouse vagina, effecting the distribution of neuropeptides with diverse roles

  3. Nerve endoneurial microstructure facilitates uniform distribution of regenerative fibers: a post hoc comparison of midgraft nerve fiber densities.

    Science.gov (United States)

    Johnson, Philip J; Newton, Piyaraj; Hunter, Daniel A; Mackinnon, Susan E

    2011-02-01

    Despite their inferiority to nerve autograft, clinical alternatives are commonly used for reconstruction of peripheral nerve injuries because of their convenient off-the-shelf availability. Previously, our group compared isografts with NeuraGen(®) (Integra, Plainsboro, NJ) nerve guides, which are a commercially available type I collagen conduit and processed rat allografts comparable to Avance(®) (AxoGen, Alachua, FL) human decellularized allograft product. From this study, qualitative observations were made of distinct differences in the pattern of regenerating fibers within conduits, acellular allografts, and isografts. In the current post hoc analysis, these observations were quantified. Using nerve density, we statistically compared the differential pattern of regenerating axon fibers within grafts and conduit. The conduits exhibited a consistent decrease in midgraft density when compared with the isograft and acellularized allografts at two gap lengths (14 mm and 28 mm) and time points (12 and 22 weeks). The decrease in density was accompanied by clustered distribution of nerve fibers in conduits, which contrasted the evenly distributed regeneration seen in processed allografts and isografts. We hypothesize that the lack of endoneurial microstructure of conduits results in the clustering regenerating fibers, and that the presence of microstructure in the acellularized allograft and isografts facilitates even distribution of regenerating fibers. © Thieme Medical Publishers.

  4. A micro-scale printable nanoclip for electrical stimulation and recording in small nerves

    Science.gov (United States)

    Lissandrello, Charles A.; Gillis, Winthrop F.; Shen, Jun; Pearre, Ben W.; Vitale, Flavia; Pasquali, Matteo; Holinski, Bradley J.; Chew, Daniel J.; White, Alice E.; Gardner, Timothy J.

    2017-06-01

    Objective. The vision of bioelectronic medicine is to treat disease by modulating the signaling of visceral nerves near various end organs. In small animal models, the nerves of interest can have small diameters and limited surgical access. New high-resolution methods for building nerve interfaces are desirable. In this study, we present a novel nerve interface and demonstrate its use for stimulation and recording in small nerves. Approach. We design and fabricate micro-scale electrode-laden nanoclips capable of interfacing with nerves as small as 50 µm in diameter. The nanoclips are fabricated using a direct laser writing technique with a resolution of 200 nm. The resolution of the printing process allows for incorporation of a number of innovations such as trapdoors to secure the device to the nerve, and quick-release mounts that facilitate keyhole surgery, obviating the need for forceps. The nanoclip can be built around various electrode materials; here we use carbon nanotube fibers for minimally invasive tethering. Main results. We present data from stimulation-evoked responses of the tracheal syringeal (hypoglossal) nerve of the zebra finch, as well as quantification of nerve functionality at various time points post implant, demonstrating that the nanoclip is compatible with healthy nerve activity over sub-chronic timescales. Significance. Our nerve interface addresses key challenges in interfacing with small nerves in the peripheral nervous system. Its small size, ability to remain on the nerve over sub-chronic timescales, and ease of implantation, make it a promising tool for future use in the treatment of disease.

  5. Association of extensive myelinated nerve fibers and high degree myopia: Case report

    OpenAIRE

    Elvan Yalcın; Ozlem Balcı; Ziya Akıngol

    2013-01-01

    Unilateral extensive myelination of the peripapillary nerve fibers may be associated with anisometropic myopia, strabismus, and reduced vision. Myelination of optic nerve fibers terminate at lamina cribrosa. Yet in some patients, myelination progresses into the peripapillary retinal nerve fibers and may affect the visual acuity. In this report, we described 4 patients. All patients presented extensive peripapillary myelinated nerve fibers associated with myopic anisometropia. After routine op...

  6. A simulation model of the electrical characteristics of human myelinated sensory nerve fibers

    NARCIS (Netherlands)

    Wesselink, W.A.; Holsheimer, J.; Sonmez, Z.; Boom, H.B.K.

    1997-01-01

    A new nerve fiber model has been developed, incorporating electrical characteristics of human myelinated sensory nerve fibers. It will be used to determine the response of myelinated somatosensory nerve fibers in the spinal cord to electrical stimulation with an epidurally placed electrode

  7. Serotonin Immunoreactive Cells and Nerve Fibers in the Mucosa of ...

    African Journals Online (AJOL)

    They appeared not to be in contact with the immunopositive endocrine and mast cells. The current study shows that serotonin may be released by the immunoreactive elements in the stomach and that future work is needed to characterize the ultrastructural features of serotonin positive nerve fibers in the pyloric mucosa.

  8. Reproducibility of corneal, macular and retinal nerve fiber layer ...

    African Journals Online (AJOL)

    Abstract. Purpose: To determine the intra-session and inter-session reproducibility of corneal, macular and retinal nerve fiber layer thick- ness (RNFL) measurements with the iVue-100 optical coherence tomography in normal eyes. Methods: These parameters were measured in the right eyes of 50 healthy participants with ...

  9. Reproducibility of corneal, macular and retinal nerve fiber layer ...

    African Journals Online (AJOL)

    Purpose: To determine the intra-session and inter-session reproducibility of corneal, macular and retinal nerve fiber layer thickness (RNFL) measurements with the iVue-100 optical coherence tomography in normal eyes. Methods: These parameters were measured in the right eyes of 50 healthy participants with normal ...

  10. Comparison of normal- and high-tension glaucoma: nerve fiber layer and optic nerve head damage.

    Science.gov (United States)

    Häntzschel, Janek; Terai, Naim; Furashova, Olga; Pillunat, Karin; Pillunat, Lutz E

    2014-01-01

    The aim of this study was to investigate differences in the nerve fiber layer and glaucoma-induced structural optic nerve head (ONH) damage in patients with normal- (NTG) and high-tension (HTG) glaucoma. In this retrospective pair-matched comparative study, 22 NTG and 22 HTG eyes were matched according to the same glaucomatous damage based on rim volume, rim area and disk size, as measured by Heidelberg retinal tomography (HRT III). Visual fields (VF) were assessed by Humphrey perimetry, and nerve fiber layer thickness was determined both by scanning laser polarimetry (GDxVCC) and spectral-domain optical coherence tomography (SD-OCT). Comparisons of all measured parameters were made between NTG and HTG groups. Based on HRT results, both NTG and HTG eyes displayed comparable structural damage to the ONH (NTG/HTG, mean: disk area, 2.30/2.31 mm(2), p = 0.942; rim area, 1.02/0.86 mm(2), p = 0.082; rim volume, 0.19/0.17 mm(3), p = 0.398). NTG eyes had significantly less VF damage than HTG eyes (NTG/HTG, mean deviation: -4.23/-12.12 dB, p = 0.002; pattern standard deviation: 5.39/8.23 dB, p = 0.022). The inferior nerve fiber layer of NTG patients was significantly thicker than that of HTG patients (NTG/HTG, mean: GDx inferior: 53.5/46.3 µm, p = 0.046). SD-OCT revealed a significantly thicker nerve fiber in NTG compared with HTG patients in all quadrants (NTG/HTG, total mean: 72.72/58.45 µm, p = 0.002). At comparable glaucomatous stages, nerve fiber loss was more advanced in HTG patients compared with NTG patients.

  11. Reproducibility of measurements with the nerve fiber analyzer (NfA/GDx).

    Science.gov (United States)

    Colen, T P; Tjon-Fo-sang, M J; Mulder, P G; Lemij, H G

    2000-10-01

    To determine the reproducibility of measurements with the Nerve Fiber Analyzer, a scanning laser polarimeter designed for quantifying glaucoma in healthy patients and patients with glaucoma. The authors also assessed the variance of measurements between instruments. Measurements were made with the third generation Nerve Fiber Analyzer, the GDx. The study consisted of three parts. In the first part, the authors measured the right eyes of 10 healthy volunteers on 5 consecutive days. In the second part, 45 patients with glaucoma underwent Nerve Fiber Analyzer measurements of one randomly selected eye on two separate days in a 5-week period. For all 14 available parameters, reproducibility of measurements was expressed in terms of 95% limits of agreement and as the intraclass correlation coefficient. The Nerve Fiber Analyzer software has an option of creating a mean image from a selection of single images; for both parts of the study, the reproducibility of measurements was calculated for a "single image," and a "mean-of-three" image. In the third part of the study, 17 volunteers underwent repeated Nerve Fiber Analyzer measurement sessions on each of three different instruments. Using multivariate analysis of variance, the authors determined the variance of measurements between instruments. The reproducibility of measurements varied considerably across parameters. Limits of agreement in mean images for superior maximum and inferior maximum were 7.2 microm and 7.7 microm, respectively in the healthy volunteers, and 8.7 microm and 7.9 microm, respectively in the patients with glaucoma. For healthy patients, the intraclass correlation coefficient was greater than 90% in 10 of 14 parameters. In patients with glaucoma, the intraclass correlation coefficient was greater than 90% in 13 of 14 parameters. Some parameters reproduced better in a mean than in a single image; these differences, however, were small and generally not statistically significant. The between

  12. Reconstruction of nerve root sheaths for sacral extradural spinal meningeal cysts with spinal nerve root fibers.

    Science.gov (United States)

    Sun, Jianjun; Wang, Zhenyu; Li, Zhendong; Wu, Haibo; Yen, Ruyu; Zheng, Mei; Chang, Qing; Liu, Isabelle Yisha

    2013-11-01

    This study analyzed the clinical characteristics and outcomes of sacral extradural spinal meningeal cysts with spinal nerve root fibers treated by reconstruction of the nerve root sheaths. The relationships between the cysts and spinal nerve root fibers were examined microscopically, the cysts were partially excised, and the defects were oversewn to reconstruct the nerve root sheaths. The Improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological function. Thirty-eight patients were included in this study, with a mean age of 41.4 ± 15.57 years. The mean IJOA score was 18.8 ± 1.32 preoperatively and 19.6 ± 0.65 postoperatively, which was a significant difference (t=-3.77, P=0.001). These results indicate a significant improvement in neurological function after surgery. The most significant improvement in neurological function was sensation (z=-2.86, P=0.004), followed by bowel/bladder function (z=-2.31, P=0.02).

  13. Evidence for small fiber neuropathy in early Parkinson's disease.

    Science.gov (United States)

    Podgorny, Peter J; Suchowersky, Oksana; Romanchuk, Kenneth G; Feasby, Thomas E

    2016-07-01

    Parkinson's disease (PD) is neurodegenerative movement disorder affecting primarily the central nervous system with several recognized non-motor symptoms that can occur at various stages of the disease. Recently it has been shown that patients with PD may be prone to peripheral nervous system pathology in the form of a peripheral neuropathy (PN). It is unclear if PN is an inherent feature of PD or if it is an iatrogenic effect of the mainstay PD treatment Levodopa. To determine if peripheral neuropathy occurs in early untreated PD we employed a case-control study design using gold standard tests for PN, including neurological examination according to the Utah Early Neuropathy Scale (UENS) and nerve conduction studies, as well as new, more sensitive and informative tests for PN including the skin biopsy and corneal confocal microscopy (CCM). We studied 26 patients with PD and 22 controls using the neurological examination and nerve conduction studies (NCS) and found no significant difference between groups except for some reduced vibration sense in the PD group. Epidermal nerve densities in the skin biopsies were similar between our cohorts. However, using CCM - a more sensitive test and a surrogate marker of small fiber damage in PN, we found that patients with PD had significantly reduced corneal nerve fiber densities and lengths as compared to controls. We conclude that our positive CCM results provide evidence of preclinical PN in newly diagnosed PD patients. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Differential activation of nerve fibers with magnetic stimulation in humans

    Directory of Open Access Journals (Sweden)

    Olree Kenneth S

    2006-07-01

    Full Text Available Abstract Background Earlier observations in our lab had indicated that large, time-varying magnetic fields could elicit action potentials that travel in only one direction in at least some of the myelinated axons in peripheral nerves. The objective of this study was to collect quantitative evidence for magnetically induced unidirectional action potentials in peripheral nerves of human subjects. A magnetic coil was maneuvered to a location on the upper arm where physical effects consistent with the creation of unidirectional action potentials were observed. Electromyographic (EMG and somatosensory evoked potential (SEP recordings were then made from a total of 20 subjects during stimulation with the magnetic coil. Results The relative amplitudes of the EMG and SEP signals changed oppositely when the current direction in the magnetic coil was reversed. This effect was consistent with current direction in the coil relative to the arm for all subjects. Conclusion A differential evocation of motor and sensory fibers was demonstrated and indicates that it may be possible to induce unidirectional action potentials in myelinated peripheral nerve fibers with magnetic stimulation.

  15. Small-Fiber Neuropathy: A Diabetic Microvascular Complication of Special Clinical, Diagnostic, and Prognostic Importance.

    Science.gov (United States)

    Körei, A E; Istenes, I; Papanas, N; Kempler, P

    2016-01-01

    Damage of small nerve fibers may lead to a large variety of clinical symptoms. Small-fiber neuropathy underlies the symptoms of painful diabetic neuropathy, which may decrease quality of life. It also contributes to the poor prognosis of diabetic neuropathy because it plays a key role in the pathogenesis of foot ulceration and autonomic neuropathy. Impairment of small nerve fibers is considered the earliest alteration in the course of diabetic neuropathy. Therefore, assessment of functional and morphological abnormalities of small nerve fibers may enable timely diagnosis. The definition, symptoms, and clinical significance of small-fiber neuropathy are considered in the present review. An apparently more complex interaction between small-fiber impairment and microcirculation is extensively discussed. Diagnostic modalities include morphometric and functional methods. Corneal confocal microscopy and punch skin biopsy are considered gold standards, but noninvasive functional tests are also diagnostically useful. However, in routine clinical practice, small-fiber neuropathy is diagnosed by its typical clinical presentation. Finally, prompt treatment should be initiated following diagnosis. © The Author(s) 2015.

  16. Responses of intact and injured sural nerve fibers to cooling and menthol.

    Science.gov (United States)

    Teliban, Alina; Bartsch, Fabian; Struck, Marek; Baron, Ralf; Jänig, Wilfrid

    2014-05-01

    Intact and injured cutaneous C-fibers in the rat sural nerve are cold sensitive, heat sensitive, and/or mechanosensitive. Cold-sensitive fibers are either low-threshold type 1 cold sensitive or high-threshold type 2 cold sensitive. The hypothesis was tested, in intact and injured afferent nerve fibers, that low-threshold cold-sensitive afferent nerve fibers are activated by the transient receptor potential melastatin 8 (TRPM8) agonist menthol, whereas high-threshold cold-sensitive C-fibers and cold-insensitive afferent nerve fibers are menthol insensitive. In anesthetized rats, activity was recorded from afferent nerve fibers in strands isolated from the sural nerve, which was either intact or crushed 6-12 days before the experiment distal to the recording site. In all, 77 functionally identified afferent C-fibers (30 intact fibers, 47 injured fibers) and 34 functionally characterized A-fibers (11 intact fibers, 23 injured fibers) were tested for their responses to menthol applied to their receptive fields either in the skin (10 or 20%) or in the nerve (4 or 8 mM). Menthol activated all intact (n = 12) and 90% of injured (n = 20/22) type 1 cold-sensitive C-fibers; it activated no intact type 2 cold-sensitive C-fibers (n = 7) and 1/11 injured type 2 cold-sensitive C-fibers. Neither intact nor injured heat- and/or mechanosensitive cold-insensitive C-fibers (n = 25) and almost no A-fibers (n = 2/34) were activated by menthol. These results strongly argue that cutaneous type 1 cold-sensitive afferent fibers are nonnociceptive cold fibers that use the TRPM8 transduction channel. Copyright © 2014 the American Physiological Society.

  17. AutoFib2: small fibers

    Science.gov (United States)

    Goodsell, Stephen J.; Blanken, Maarten F.; Corradi, Romano; Dee, Kevin M.; Jolley, P. D.

    2003-03-01

    In July 2001, AutoFib-2 (AF2), the prime focus robotic fiber positioner for the Isaac Newton Group's (ING) 4.2m William Hershel Telescope (WHT) had its new Small Fiber Module (SFM) successfully commissioned. The new SFM contains 150 science fibers and 10 fiducial bundles. Each science fiber has a diameter of 90 μm, which corresponds to 1.6 arcsec in the sky. The continuous science fibers are fed into the Nasmyth platform Wide Field Fiber Optic Spectrograph (WYFFOS). Each fiducial bundle, 450 μm in diameter, contains 10,000 coherent fibers providing a rough imaging capability over an 8 arcsec round field. This paper looks at the reasons for developing this module, examines its mechanical design, describes its new science and fiducial fibers, looks at the fiber alignment techniques used, explains the new guiding system and briefly discusses changes in the AF2 control system. It continues to reveal the results of some fiber characterization experiments performed on sky and gives an example of a recent science run. The paper concludes with a section that lists planned AF2 enhancements.

  18. European Federation of Neurological Societies/Peripheral Nerve Society Guideline on the use of skin biopsy in the diagnosis of small fiber neuropathy. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society.

    Science.gov (United States)

    Lauria, G; Hsieh, S T; Johansson, O; Kennedy, W R; Leger, J M; Mellgren, S I; Nolano, M; Merkies, I S J; Polydefkis, M; Smith, A G; Sommer, C; Valls-Solé, J

    2010-07-01

    Revision of the guidelines on the use of skin biopsy in the diagnosis of peripheral neuropathy, published in 2005, has become appropriate owing to publication of more relevant articles. Most of the new studies focused on small fiber neuropathy (SFN), a subtype of neuropathy for which the diagnosis was first developed through skin biopsy examination. This revision focuses on the use of this technique to diagnose SFN. Task force members searched the Medline database from 2005, the year of the publication of the first EFNS guideline, to June 30th, 2009. All pertinent articles were rated according to the EFNS and PNS guidance. After a consensus meeting, the task force members created a manuscript that was subsequently revised by two experts (JML and JVS) in the field of peripheral neuropathy and clinical neurophysiology, who were not previously involved in the use of skin biopsy. Distal leg skin biopsy with quantification of the linear density of intraepidermal nerve fibers (IENF), using generally agreed upon counting rules, is a reliable and efficient technique to assess the diagnosis of SFN (Recommendation Level A). Normative reference values are available for bright-field immunohistochemistry (Recommendation Level A) but not yet for confocal immunofluorescence or the blister technique. The morphometric analysis of IENF density, either performed with bright-field or immunofluorescence microscopy, should always refer to normative values matched for age (Recommendation Level A). Newly established laboratories should undergo adequate training in a well-established skin biopsy laboratory and provide their own stratified for age and gender normative values, intra- and interobserver reliability, and interlaboratory agreement. Quality control of the procedure at all levels is mandatory (Good Practice Point). Procedures to quantify subepidermal nerve fibers and autonomic innervated structures, including erector pili muscles, and skin vessels, are under development but need

  19. Comparison of probabilistic and deterministic fiber tracking of cranial nerves.

    Science.gov (United States)

    Zolal, Amir; Sobottka, Stephan B; Podlesek, Dino; Linn, Jennifer; Rieger, Bernhard; Juratli, Tareq A; Schackert, Gabriele; Kitzler, Hagen H

    2017-09-01

    OBJECTIVE The depiction of cranial nerves (CNs) using diffusion tensor imaging (DTI) is of great interest in skull base tumor surgery and DTI used with deterministic tracking methods has been reported previously. However, there are still no good methods usable for the elimination of noise from the resulting depictions. The authors have hypothesized that probabilistic tracking could lead to more accurate results, because it more efficiently extracts information from the underlying data. Moreover, the authors have adapted a previously described technique for noise elimination using gradual threshold increases to probabilistic tracking. To evaluate the utility of this new approach, a comparison is provided with this work between the gradual threshold increase method in probabilistic and deterministic tracking of CNs. METHODS Both tracking methods were used to depict CNs II, III, V, and the VII+VIII bundle. Depiction of 240 CNs was attempted with each of the above methods in 30 healthy subjects, which were obtained from 2 public databases: the Kirby repository (KR) and Human Connectome Project (HCP). Elimination of erroneous fibers was attempted by gradually increasing the respective thresholds (fractional anisotropy [FA] and probabilistic index of connectivity [PICo]). The results were compared with predefined ground truth images based on corresponding anatomical scans. Two label overlap measures (false-positive error and Dice similarity coefficient) were used to evaluate the success of both methods in depicting the CN. Moreover, the differences between these parameters obtained from the KR and HCP (with higher angular resolution) databases were evaluated. Additionally, visualization of 10 CNs in 5 clinical cases was attempted with both methods and evaluated by comparing the depictions with intraoperative findings. RESULTS Maximum Dice similarity coefficients were significantly higher with probabilistic tracking (p cranial nerves. Probabilistic tracking with a gradual

  20. Neurophysiological approach to disorders of peripheral nerve

    DEFF Research Database (Denmark)

    Crone, Clarissa; Krarup, Christian

    2013-01-01

    Disorders of the peripheral nerve system (PNS) are heterogeneous and may involve motor fibers, sensory fibers, small myelinated and unmyelinated fibers and autonomic nerve fibers, with variable anatomical distribution (single nerves, several different nerves, symmetrical affection of all nerves......, plexus, or root lesions). Furthermore pathological processes may result in either demyelination, axonal degeneration or both. In order to reach an exact diagnosis of any neuropathy electrophysiological studies are crucial to obtain information about these variables. Conventional electrophysiological...

  1. A mathematical description of nerve fiber bundle trajectories and their variability in the human retina

    NARCIS (Netherlands)

    Jansonius, N. M.; Nevalainen, J.; Selig, B.; Zangwill, L. M.; Sample, P. A.; Budde, W. M.; Jonas, J. B.; Lagreze, W. A.; Airaksinen, P. J.; Vonthein, R.; Levin, L. A.; Paetzold, J.; Schiefer, U.

    2009-01-01

    We developed a mathematical model wherein retinal nerve fiber trajectories can be described and the corresponding inter-subject variability analyzed. The model was based on traced nerve fiber bundle trajectories extracted from 55 fundus photographs of 55 human subjects. The model resembled the

  2. Evaluation of proxy tests for SFSN: evidence for mixed small and large fiber dysfunction.

    Directory of Open Access Journals (Sweden)

    Hamid Ebadi

    Full Text Available BACKGROUND: Though intra-epidermal nerve fiber density (IENFD is considered the gold standard for diagnosis of small fiber sensory neuropathy (SFSN, we aimed to determine if novel threshold values derived from standard tests of small or large fiber function could serve as diagnostic alternatives. METHODS: Seventy-four consecutive patients with painful polyneuropathy and normal nerve conduction studies (NCS were defined as SFSN cases or controls by distal IENFD <5.4 and ≥5.4 fibers/mm, respectively. Diagnostic performance of small fiber [cooling (CDT and heat perception (HP thresholds, axon reflex-mediated neurogenic vasodilatation] and large fiber function tests [vibration perception thresholds (VPT and sural nerve conduction parameters] were determined by receiver operating-characteristic (ROC curve analyses. RESULTS: The 26(35% SFSN cases had mean IENFD 3.3±1.7 fibers/mm and the 48(65% controls 9.9±2.9 fibers/mm. Male gender (p = 0.02 and older age (p = 0.02 were associated with SFSN cases compared to controls. VPT were higher and CDT lower in SFSN cases, but the largest magnitude of differences was observed for sural nerve amplitude. It had the greatest area under the ROC curve (0.75 compared to all other tests (p<0.001 for all comparisons and the optimal threshold value of ≤12 µV defined SFSN cases with 80% sensitivity and 72% specificity. CONCLUSION: In patients presenting with polyneuropathy manifestations and normal NCS, though small fiber function tests were intuitively considered the best alternative measures to predict reduced IENFD, their diagnostic performance was poor. Instead, novel threshold values within the normal range for large fiber tests should be considered as an alternative strategy to select subjects for skin biopsy in diagnostic protocols for SFSN.

  3. [Usefulness of skin biopsy in the diagnosis of small fiber neuropathy].

    Science.gov (United States)

    Magy, Laurent; Richard, Laurence; Vallat, Jean-Michel

    2012-06-01

    Diagnosis of small fiber neuropathy may be challenging due to subtle clinical signs and to the normality of nerve conduction studies. Skin biopsy is a non invasive method which allows to quantify intraepidermal nerve fiber density after a simple immunostaining. The values measured must ideally be compared to normative data obtained on control subjects in order to determine their significance. When the diagnosis of small fiber neuropathy has been made by means of skin biopsy, possibly combined with laser evoked potentials, a diagnostic work up has to be done in order to find one of the classical causes of this disorder. To date, skin biopsy is useful to confirm the diagnosis of small fiber neuropathy but lacks utility to find its etiology. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  4. A distributed-parameter model of the myelinated nerve fiber.

    Science.gov (United States)

    Halter, J A; Clark, J W

    1991-02-07

    This paper presents a new model for the characterization of electrical activity in the nodal, paranodal and internodal regions of isolated amphibian and mammalian myelinated nerve fibers. It differs from previous models in the following ways: (1) in its ability to incorporate detailed anatomical and electrophysiological data; (2) in its approach to the myelinated nerve fiber as a multi-axial cable; and (3) in the numerical algorithm used to obtain distributed model equation solutions for potential and current. The morphometric properties are taken from detailed electron microscopic anatomical studies (Berthold & Rydmark, 1983a, Experientia 39, 964-976). The internodal axolemma is characterized as an excitable membrane and model-generated nodal and internodal membrane action potentials are presented. A system of describing equations for the equivalent network model is derived, based on the application of Kirchoff's Current Law, which take the form of multiple cross-coupled parabolic partial differential equations. An implicit numerical integration method is developed and the numerical solution implemented on a parallel processor. Non-uniform spatial step sizes are used, enabling detailed representation of the nodal region while minimizing the number of total segments necessary to represent the overall fiber. Conduction velocities of 20.2 m sec-1 at 20 degrees C for a 15 microns diameter amphibian fiber and 57.6 m sec-1 at 37 degrees C for a 17.5 microns diameter mammalian fiber are achieved, which agrees qualitatively with published experimental data at similar temperatures (Huxley & Stämpfli, 1949, J. Physiol., Lond. 108, 315-339; Rasminsky, 1973, Arch, Neurol. 28, 287-292). The simulation results demonstrate the ability of this model to produce detailed representations of the transaxonal, transmyelin and transfiber potentials and currents, as well as the longitudinal extra-axonal, periaxonal and intra-axonal currents. Also indicated is the potential contribution

  5. Representation of voice pitch in discharge patterns of auditory-nerve fibers.

    Science.gov (United States)

    Miller, M I; Sachs, M B

    1984-06-01

    Responses of populations of auditory-nerve fibers were measured for synthesized consonant-vowel stimuli. This paper explores the encoding of fundamental frequency (pitch) in these responses. Post-stimulus time (PST) histograms were computed from 25 ms segments of the spike trains. Discrete Fourier transforms with a 40 Hz resolution were computed from the histograms. Two representations of pitch are considered. The first representation is based on the pitch-related temporal properties of the speech signal. Histograms for individual units can show envelope modulations directly related to the pitch period. These modulations reflect the responses of these fibers to a number of stimulus harmonics near fiber CF. Responses of fibers near formant frequencies are dominated by a single large harmonic component, and thus show small or no pitch-related enveloped modulations. Envelope modulations are reduced in the presence of background noise. The second representation uses both temporal properties of auditory-nerve responses and cochlear place to encode the pitch-related harmonic structure of speech. As a measure of the response of the population of fibers to each harmonic of 40 Hz the magnitude of the component of the Fourier transform at that frequency was averaged across all fibers whose characteristic frequencies were within one-fourth octave of that harmonic. We call this measure the average localized synchronized rate (ALSR). The ALSR provides a good representation of stimulus spectrum, even in the presence of background noise. From the harmonic structure of the ALSR, we are able to extract the stimulus pitch frequency. The relationship of these two representations to pitch perception in both acoustic and electrical stimulation (via cochlear implants) is discussed.

  6. NRP-1 Receptor Expression Mismatch in Skin of Subjects with Experimental and Diabetic Small Fiber Neuropathy.

    Science.gov (United States)

    Van Acker, Nathalie; Ragé, Michael; Vermeirsch, Hilde; Schrijvers, Dorien; Nuydens, Rony; Byttebier, Geert; Timmers, Maarten; De Schepper, Stefanie; Streffer, Johannes; Andries, Luc; Plaghki, Léon; Cras, Patrick; Meert, Theo

    2016-01-01

    The in vivo cutaneous nerve regeneration model using capsaicin is applied extensively to study the regenerative mechanisms and therapeutic efficacy of disease modifying molecules for small fiber neuropathy (SFN). Since mismatches between functional and morphological nerve fiber recovery are described for this model, we aimed at determining the capability of the capsaicin model to truly mimic the morphological manifestations of SFN in diabetes. As nerve and blood vessel growth and regenerative capacities are defective in diabetes, we focused on studying the key regulator of these processes, the neuropilin-1 (NRP-1)/semaphorin pathway. This led us to the evaluation of NRP-1 receptor expression in epidermis and dermis of subjects presenting experimentally induced small fiber neuropathy, diabetic polyneuropathy and of diabetic subjects without clinical signs of small fiber neuropathy. The NRP-1 receptor was co-stained with CD31 vessel-marker using immunofluorescence and analyzed with Definiens® technology. This study indicates that capsaicin application results in significant loss of epidermal NRP-1 receptor expression, whereas diabetic subjects presenting small fiber neuropathy show full epidermal NRP-1 expression in contrast to the basal expression pattern seen in healthy controls. Capsaicin induced a decrease in dermal non-vascular NRP-1 receptor expression which did not appear in diabetic polyneuropathy. We can conclude that the capsaicin model does not mimic diabetic neuropathy related changes for cutaneous NRP-1 receptor expression. In addition, our data suggest that NRP-1 might play an important role in epidermal nerve fiber loss and/or defective regeneration and that NRP-1 receptor could change the epidermal environment to a nerve fiber repellant bed possibly through Sem3A in diabetes.

  7. Incorporation of fiber optic beam shaping into a laparoscopic probe for laser stimulation of the cavernous nerves

    Science.gov (United States)

    Tozburun, Serhat; Lagoda, Gwen A.; Mayeh, Mona; Burnett, Arthur L.; Farahi, Faramarz; Fried, Nathaniel M.

    2010-02-01

    The cavernous nerves (CN) course along the prostate surface and are responsible for erectile function. Improved identification and preservation of the CN's is critical to maintaining sexual potency after prostate cancer surgery. Noncontact optical nerve stimulation (ONS) of the CN's was recently demonstrated in a rat model, in vivo, as a potential alternative to electrical nerve stimulation (ENS) for identification of the CN's during prostate surgery. However, the therapeutic window for ONS is narrow, so optimal design of the fiber optic delivery system is critical for safe, reproducible stimulation. This study describes modeling, assembly, and testing of an ONS probe for delivering a small, collimated, flat-top laser beam for uniform CN stimulation. A direct comparison of the magnitude and response time of the intracavernosal pressure (ICP) for both Gaussian and flat-top spatial beam profiles was performed. Thulium fiber laser radiation (λ=1870 nm) was delivered through a 200-μm fiber, with distal fiber tip chemically etched to convert a Gaussian to flat-top beam profile. The laser beam was collimated to a 1-mm-diameter spot using an aspheric lens. Computer simulations of light propagation were used to optimize the probe design. The 10-Fr (3.4-mm-OD) laparoscopic probe provided a constant radiant exposure at the nerve surface. The probe was tested in four rats, in vivo. ONS of the CN's was performed with a 1-mm-diameter spot, 5- ms pulse duration, and pulse rate of 20 Hz for a duration of 15-30 s. The flat-top laser beam profile consistently produced a faster and higher ICP response at a lower radiant exposure than the Gaussian beam profile due, in part, to easier alignment of the more uniform beam with nerve. With further development, ONS may be used as a diagnostic tool for identification of the CN's during laparoscopic and robotic nerve-sparing prostate cancer surgery.

  8. Small fiber neuropathy is a common feature of Ehlers-Danlos syndromes

    Science.gov (United States)

    Cazzato, Daniele; Castori, Marco; Lombardi, Raffaella; Caravello, Francesca; Bella, Eleonora Dalla; Petrucci, Antonio; Grammatico, Paola; Dordoni, Chiara; Colombi, Marina

    2016-01-01

    Objective: To investigate the involvement of small nerve fibers in Ehlers-Danlos syndrome (EDS). Methods: Patients diagnosed with EDS underwent clinical, neurophysiologic, and skin biopsy assessment. We recorded sensory symptoms and signs and evaluated presence and severity of neuropathic pain according to the Douleur Neuropathique 4 (DN4) and ID Pain questionnaires and the Numeric Rating Scale (NRS). Sensory action potential amplitude and conduction velocity of sural nerve was recorded. Skin biopsy was performed at distal leg and intraepidermal nerve fiber density (IENFD) obtained and referred to published sex- and age-adjusted normative reference values. Results: Our cohort included 20 adults with joint hypermobility syndrome/hypermobility EDS, 3 patients with vascular EDS, and 1 patient with classic EDS. All except one patient had neuropathic pain according to DN4 and ID Pain questionnaires and reported 7 or more symptoms at the Small Fiber Neuropathy Symptoms Inventory Questionnaire. Pain intensity was moderate (NRS ≥4 and <7) in 8 patients and severe (NRS ≥7) in 11 patients. Sural nerve conduction study was normal in all patients. All patients showed a decrease of IENFD consistent with the diagnosis of small fiber neuropathy (SFN), regardless of the EDS type. Conclusions: SFN is a common feature in adults with EDS. Skin biopsy could be considered an additional diagnostic tool to investigate pain manifestations in EDS. PMID:27306637

  9. Association of extensive myelinated nerve fibers and high degree myopia: case report.

    Science.gov (United States)

    Yalcın, Elvan; Balcı, Ozlem; Akıngol, Ziya

    2013-10-01

    Unilateral extensive myelination of the peripapillary nerve fibers may be associated with anisometropic myopia, strabismus, and reduced vision. Myelination of optic nerve fibers terminate at lamina cribrosa. Yet in some patients, myelination progresses into the peripapillary retinal nerve fibers and may affect the visual acuity. In this report, we described 4 patients. All patients presented extensive peripapillary myelinated nerve fibers associated with myopic anisometropia. After routine ophthalmic and orthoptic examinations, all patients underwent treatment for amblyopia through correction with spectacles, contact lenses, and the occlusion of the good eye. Corrected visual acuity improved in 1 patient, but 3 patients had no increase in visual acuity despite treatment with full cycloplegic refraction and appropriate patching. Probably because of structural abnormalies of the macula, visual results are often disappointing with appropriate correction of the refractive error and occlusion.

  10. Wiener-Kernel Analysis of Responses to Noise of Chinchilla Auditory-Nerve Fibers

    National Research Council Canada - National Science Library

    Alberto Recio-Spinoso; Andrei N. Temchin; Pim van Dijk; Yun-Hui Fan; Mario A. Ruggero

    2005-01-01

    Responses to broadband Gaussian white noise were recorded in auditory-nerve fibers of deeply anesthetized chinchillas and analyzed by computation of zeroth-, first-, and second-order Wiener kernels...

  11. Association of extensive myelinated nerve fibers and high degree myopia: Case report

    Directory of Open Access Journals (Sweden)

    Elvan Yalcın

    2013-01-01

    Full Text Available Unilateral extensive myelination of the peripapillary nerve fibers may be associated with anisometropic myopia, strabismus, and reduced vision. Myelination of optic nerve fibers terminate at lamina cribrosa. Yet in some patients, myelination progresses into the peripapillary retinal nerve fibers and may affect the visual acuity. In this report, we described 4 patients. All patients presented extensive peripapillary myelinated nerve fibers associated with myopic anisometropia. After routine ophthalmic and orthoptic examinations, all patients underwent treatment for amblyopia through correction with spectacles, contact lenses, and the occlusion of the good eye. Corrected visual acuity improved in 1 patient, but 3 patients had no increase in visual acuity despite treatment with full cycloplegic refraction and appropriate patching. Probably because of structural abnormalies of the macula, visual results are often disappointing with appropriate correction of the refractive error and occlusion.

  12. Determination of Nerve Fiber Diameter Distribution From Compound Action Potential: A Continuous Approach.

    Science.gov (United States)

    Un, M Kerem; Kaghazchi, Hamed

    2018-01-01

    When a signal is initiated in the nerve, it is transmitted along each nerve fiber via an action potential (called single fiber action potential (SFAP)) which travels with a velocity that is related with the diameter of the fiber. The additive superposition of SFAPs constitutes the compound action potential (CAP) of the nerve. The fiber diameter distribution (FDD) in the nerve can be computed from the CAP data by solving an inverse problem. This is usually achieved by dividing the fibers into a finite number of diameter groups and solve a corresponding linear system to optimize FDD. However, number of fibers in a nerve can be measured sometimes in thousands and it is possible to assume a continuous distribution for the fiber diameters which leads to a gradient optimization problem. In this paper, we have evaluated this continuous approach to the solution of the inverse problem. We have utilized an analytical function for SFAP and an assumed a polynomial form for FDD. The inverse problem involves the optimization of polynomial coefficients to obtain the best estimate for the FDD. We have observed that an eighth order polynomial for FDD can capture both unimodal and bimodal fiber distributions present in vivo, even in case of noisy CAP data. The assumed FDD distribution regularizes the ill-conditioned inverse problem and produces good results.

  13. The absence of CD47 promotes nerve fiber growth from cultured ventral mesencephalic dopamine neurons.

    Directory of Open Access Journals (Sweden)

    Franziska Marschinke

    Full Text Available In ventral mesencephalic organotypic tissue cultures, two timely separated sequences of nerve fiber growth have been observed. The first appearing nerve fiber pattern is a long-distance outgrowth that occurs before astrocytes start to proliferate and migrate to form an astrocytic monolayer that finally surrounds the tissue slice. These long-distance growing nerve fibers are retracted as the astrocytes migrate, and are followed by a secondary outgrowth. The secondary outgrowth is persistent in time but reaches short distances, comparable with outgrowth seen from a dopaminergic graft implanted to the brain. The present study was focused on the interaction between the astrocytes and the long-distance growing non-glial associated nerve fibers. Cross talk between astroglia and neurite formation might occur through the integrin-associated protein CD47. CD47 serves as a ligand for signal regulatory protein (SIRP α and as a receptor for the extracellular matrix protein thrombospondin-1 (TSP-1. Embryonic day 14 ventral mesencephalic tissue from CD47(+/+ and CD47(-/- mice was used to investigate astrocytic migration and the tyrosine hydroxylase (TH -positive outgrowth that occurred remote from the astrocytes. TH-immunohistochemistry demonstrated that the non-glial-associated nerve fiber outgrowth in CD47(-/- cultures reached significantly longer distances and higher density compared to nerve fibers formed in CD47(+/+ cultures at 14 days in vitro. These nerve fibers often had a dotted appearance in CD47(+/+ cultures. No difference in the astrocytic migration was observed. Further investigations revealed that the presence of CD47 in control culture did neither hamper non-glial-associated growth through SIRPα nor through TSP-1 since similar outgrowth was found in SIRPα mutant cultures and in CD47(+/+ cultures treated with blocking antibodies against the TSP-1, respectively, as in the control cultures. In conclusion, long-distance growing nerve fiber

  14. Myelinated and unmyelinated nerve fibers reinnervate tissue-engineered dermo-epidermal human skin analogs in an in vivo model.

    Science.gov (United States)

    Biedermann, T; Klar, A S; Böttcher-Haberzeth, S; Reichmann, E; Meuli, M

    2016-12-01

    The clinical application of autologous tissue-engineered skin analogs is an important strategy to cover large skin defects. Investigating biological dynamics, such as reinnervation after transplantation, is essential to improve the quality of such skin analogs. Previously, we have examined that our skin substitutes are reinnervated by host peripheral nerve fibers as early as 8 weeks after transplantation. Here, we wanted to investigate the presence and possible differences regarding myelinated and unmyelinated host nerve fibers 15 weeks after the transplantation of light and dark human tissue-engineered skin analogs. Human epidermal keratinocytes, melanocytes, and dermal fibroblasts were isolated from human light and dark skin biopsies. Keratinocytes and melanocytes were seeded on fibroblast-containing collagen type I hydrogels after expansion in culture. After additional culturing, the tissue-engineered dermo-epidermal skin analogs were transplanted onto full-thickness skin wounds created on the back of immuno-incompetent rats. Skin substitutes were excised and analyzed 15 weeks after transplantation. Histological sections were examined with regard to the ingrowth pattern of myelinated and unmyelinated nerve fibers into the skin analogs using markers, such as Substance P, NF200, and S100-Beta. We found myelinated and unmyelinated peripheral host nerve fibers 15 weeks after transplantation in the dermal part of our human skin substitutes. In particular, we identified large-diameter-myelinated Aβ- and Aδ-fibers, and small-diameter C-fibers. Furthermore, we observed myelinated nerves in close proximity to CD31-positive blood capillaries. In the long run, both types of ingrown host fibers showed an identical pattern in both light and dark skin analogs. Our data suggest that myelinated and unmyelinated peripheral nerves reinnervate human skin substitutes in a long-term in vivo transplantation assay. Our tissue-engineered skin analogs attract A- and C-fibers to

  15. Study on corneal Langerhans cells and pathological changes of nerve fibers in diabetic patients

    Directory of Open Access Journals (Sweden)

    Zhi-Hua Han

    2016-02-01

    Full Text Available AIM: To study the relation between corneal epithelium Langerhans cells(LCsand pathological changes of nerve fibers in patients with diabetic peripheral neuropathy in order to further analyze the pathogenesis and find the possible role of immune mechanism in this process. METHODS: We selected 60 patients with diabetic neuropathy and 32 healthy controls to observe the morphology, number and length of corneal nerve fibers, corneal central sensation and the cell density of LCs to analyze the correlation of the two. RESULTS: The number, length and the number of branches of corneal nerve fibers obvious declined in the patients with diabetic neuropathy. The curling degree of nerve fiber of diabetes group was obviously increased. The density of LCs at corneal central and peripheral areas in patients with diabetic neuropathy significantly increased compared to those of normal control group(Pr =0.461, P=0.011, LCs and nerve fiber length(r=0.519, P=0.002. And corneal central sensation decreased obviously in patients with diabetic neuropathy compared to that in normal control(PCONCLUSION: In patients with diabetic neuropathy, the nerve fibers are significantly impaired, corneal sensation decreases and number of LCs significantly increases, which suggests that the changes might be mediated by the immune mechanism.

  16. Peripheral origins and functional characteristics of vibration-sensitive VIIIth nerve fibers in the frog Rana temporaria

    DEFF Research Database (Denmark)

    Jøgensen, Morten Buhl; Christensen-Dalsgaard, Jakob

    1991-01-01

    were studied. 2) Vibration-sensitive fibers were found in both the anterior and posterior branch of the VIIIth nerve. 3) No vibration-sensitive fibers were found in the lagenar nerve. 4) The vibration-sensitive fibers in the posterior branch probably innervated the amphibian papilla and many...

  17. Peptidergic nerve fibers in the urethra: Morphological and neurochemical characteristics in female mice of reproductive age.

    Science.gov (United States)

    Barry, Christine M; Ji, Esther; Sharma, Harman; Yap, Pauline; Spencer, Nicholas J; Matusica, Dusan; Haberberger, Rainer V

    2017-10-20

    Peptidergic nerve fibers provide important contributions to urethral function. Urethral innervation of female mice is not well documented. To determine the distribution and projection sites of nerve fibers immunoreactive for vasoactive intestinal peptide (VIP), calcitonin gene-related peptide (CGRP), substance P (SP), and neuropeptide Y (NPY) in the urethra of wild-type control mice and compare innervation characteristics between the proximal and distal urethra of young nullipara and older multipara mice. Furthermore, to identify the location and neurochemical coding of the spinal afferent nerve endings in the urethra, whose sensory neurons reside in lumbosacral dorsal root ganglia (DRG). Multiple labeling immunohistochemistry of urethral sections of nulliparous (6-8 weeks old), and multiparous (9-12 months old) mice, and anterograde axonal tracing from L5-S2 (DRG) in vivo. Abundant VIP-, CGRP-, SP-, and NPY-immunoreactive nerve fibers were identified in the adventitia, muscularis, and lamina propria of proximal and distal segments of the urethra. A proportion of fibers were closely associated with blood vessels, glands, and cells immunoreactive for PGP9.5. The epithelium contained abundant nerve fibers immunoreactive for CGRP and/or SP. Epithelial innervation was increased in the distal urethra of multipara mice. Abundant fibers were traced from L5-S2 DRG to all urethral regions. We present the first identification of spinal afferent endings in the urethra. Peptidergic nerve fibers, including multiple populations of spinal afferents, provide rich innervation of the female mouse urethra. The morphology of fibers in the epithelium and other regions suggests multiple nerve-cell interactions impacting on urethral function. © 2017 Wiley Periodicals, Inc.

  18. Diagnostic Ability of Retinal Nerve Fiber Layer Thickness Deviation Map for Localized and Diffuse Retinal Nerve Fiber Layer Defects

    Directory of Open Access Journals (Sweden)

    Joong Won Shin

    2017-01-01

    Full Text Available Purpose. To evaluate the diagnostic ability of the retinal nerve fiber layer (RNFL deviation map for glaucoma with localized or diffuse RNFL defects. Methods. Eyes of 139 glaucoma patients and 165 healthy subjects were enrolled. All participants were imaged with Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA. A RNFL defect was defined as at least 10 contiguous red (<1% level superpixels in RNFL deviation map. The area, location, and angular width of RNFL defects were automatically measured. We compared sensitivities, specificities, and area under the receiver operating characteristic curves (AUCs of RNFL deviation map and circumpapillary RNFL thickness for localized and diffuse RNFL defects. Subgroup analysis was performed according to the severity of glaucoma. Results. For localized defects, the area of RNFL defects (AUC, 0.991; sensitivity, 97%; specificity, 90% in deviation map showed a higher diagnostic performance (p=0.002 than the best circumpapillary RNFL parameter (inferior RNFL thickness; AUC, 0.914; sensitivity, 79%; specificity, 92%. For diffuse defects, there was no significant difference between the RNFL deviation map and circumpapillary RNFL parameters. In mild glaucoma with localized defect, RNFL deviation map showed a better diagnostic performance than circumpapillary RNFL measurement. Conclusions. RNFL deviation map is a useful tool for evaluating glaucoma regardless of localized or diffuse defect type and has advantages over circumpapillary RNFL measurement for detecting localized RNFL defects.

  19. Retinal nerve fiber layer thickness and neuropsychiatric manifestations in systemic lupus erythematosus.

    Science.gov (United States)

    Shulman, S; Shorer, R; Wollman, J; Dotan, G; Paran, D

    2017-11-01

    Background Cognitive impairment is frequent in systemic lupus erythematosus. Atrophy of the corpus callosum and hippocampus have been reported in patients with systemic lupus erythematosus, and diffusion tensor imaging studies have shown impaired white matter integrity, suggesting that white matter damage in systemic lupus erythematosus may underlie the cognitive impairment as well as other neuropsychiatric systemic lupus erythematosus manifestations. Retinal nerve fiber layer thickness, as assessed by optical coherence tomography, has been suggested as a biomarker for white matter damage in neurologic disorders such as multiple sclerosis, Alzheimer's disease and Parkinson's disease. Retinal nerve fiber layer thinning may occur early, even in patients with mild clinical symptoms. Aim The objective of this study was to assess the association of retinal nerve fiber layer thickness, as a biomarker of white matter damage in systemic lupus erythematosus patients, with neuropsychiatric systemic lupus erythematosus manifestations, including cognitive impairment. Methods Twenty-one consecutive patients with systemic lupus erythematosus underwent neuropsychological testing using a validated computerized battery of tests as well as the Rey-Auditory verbal learning test. All 21 patients, as well as 11 healthy, age matched controls, underwent optical coherence tomography testing to assess retinal nerve fiber layer thickness. Correlations between retinal nerve fiber layer thickness and results in eight cognitive domains assessed by the computerized battery of tests as well as the Rey-Auditory verbal learning test were assessed in patients with systemic lupus erythematosus, with and without neuropsychiatric systemic lupus erythematosus, and compared to retinal nerve fiber layer thickness in healthy controls. Results No statistically significant correlation was found between retinal nerve fiber layer thickness in patients with systemic lupus erythematosus as compared to healthy

  20. Wiener-kernel analysis of responses to noise of chinchilla auditory-nerve fibers

    NARCIS (Netherlands)

    Recio-Spinoso, A; Temchin, AN; van Dijk, P; Fan, YH; Ruggero, MA

    Responses to broadband Gaussian white noise were recorded in auditory-nerve fibers of deeply anesthetized chinchillas and analyzed by computation of zeroth-, first-, and second-order Wiener kernels. The first- order kernels ( similar to reverse correlations or "revcors") of fibers with

  1. Small fiber neuropathy in women with fibromyalgia. An in vivo assessment using corneal confocal bio-microscopy.

    Science.gov (United States)

    Ramírez, Manuel; Martínez-Martínez, Laura-Aline; Hernández-Quintela, Everardo; Velazco-Casapía, Jorge; Vargas, Angélica; Martínez-Lavín, Manuel

    2015-10-01

    A consistent line of investigation suggests that fibromyalgia is a neuropathic pain syndrome. This outlook has been recently reinforced by several controlled studies that describe decreased small nerve fiber density in skin biopsies of patients with fibromyalgia. The cornea receives the densest small fiber innervation of the body. Corneal confocal bio-microscopy is a new noninvasive method to evaluate small nerve fiber morphology. Our objective was to assess corneal small nerve fiber morphology in patients with fibromyalgia, and to associate corneal nerve microscopic features with neuropathic pain descriptors and other fibromyalgia symptoms. We studied 17 female patients with fibromyalgia and 17 age-matched healthy control subjects. All the participants completed different questionnaires regarding the symptoms of fibromyalgia, including a neuropathic pain survey. A central corneal thickness scan was obtained with a confocal microscope. Nerve measurements were made by a single ophthalmologist without knowledge of the clinical diagnosis. Stromal nerve thickness was defined as the mean value between the widest and the narrowest portion of each analyzed stromal nerve. Corneal sub-basal plexus nerve density was also assessed. Patients with fibromyalgia had stromal nerve thickness of 5.0 ± 1.0 µm (mean ± standard deviation) significantly different from that of control's values (6.1 ± 1.3) p = 0.01. Patients also had decreased sub-basal plexus nerve density per square millimeter (85 ± 29) vs. 107 ± 26 of controls p = 0.02. When controls and patients were grouped together, there was an association between stromal nerve slenderness and neuropathic pain descriptors (Fisher's exact test p = 0.007). Women suffering from fibromyalgia have thinner corneal stromal nerves and diminished sub-basal plexus nerve density when compared to healthy controls. Nerve scarcity is associated with neuropathic pain descriptors. Small fiber neuropathy may play a role in the pathogenesis of

  2. [Morphological features and analysis of the nerve fibers in the periodontal ligament of dogs].

    Science.gov (United States)

    Xiaohua, Zeng; Qiaoling, Cai; Ping, Gong

    2016-10-01

    To identify the properties of nerve fibers of dogs by immunohistochemical staining method. Intact bone blocks above the inferior alveolar nerve canal were cut from the medial of the second premolar to the distal of the third premolar of healthy adult Beagle dogs of 18 months, embedded to make hard tissue sections, stained with S100 and neurofilament protein (NFP) antibodies, and finally observed the nerve distribution under the microscope. The distribution of S100 positive tissue in the periodontal ligament of dogs showed the following patterns: bundles of densely gathered rings with different diameters, filaments accompanied by lumens, free endings and deep-dyeing oval lamellasome. The location of NFP positive tissue was similar to that of S100 positive tissue, but the distribution of these NFP positive filaments with various diameters showed largely as bundles, free ending and branches scattering in periodontal membrane. We may firstly distinguish the structure of the nerve fibers in periodontal ligament of nerve distribution, and then judge the categories of the nerve fibers by S100 immunohistochemistry furtherly according to comparison of the thickness of neural axon by NFP immunohistochemistry, and finally distinct the function and attribute of the nerve fibers in the periodontal ligament of dogs. 
.

  3. The role of the renal afferent and efferent nerve fibers in heart failure

    Science.gov (United States)

    Booth, Lindsea C.; May, Clive N.; Yao, Song T.

    2015-01-01

    Renal nerves contain afferent, sensory and efferent, sympathetic nerve fibers. In heart failure (HF) there is an increase in renal sympathetic nerve activity (RSNA), which can lead to renal vasoconstriction, increased renin release and sodium retention. These changes are thought to contribute to renal dysfunction, which is predictive of poor outcome in patients with HF. In contrast, the role of the renal afferent nerves remains largely unexplored in HF. This is somewhat surprising as there are multiple triggers in HF that have the potential to increase afferent nerve activity, including increased venous pressure and reduced kidney perfusion. Some of the few studies investigating renal afferents in HF have suggested that at least the sympatho-inhibitory reno-renal reflex is blunted. In experimentally induced HF, renal denervation, both surgical and catheter-based, has been associated with some improvements in renal and cardiac function. It remains unknown whether the effects are due to removal of the efferent renal nerve fibers or afferent renal nerve fibers, or a combination of both. Here, we review the effects of HF on renal efferent and afferent nerve function and critically assess the latest evidence supporting renal denervation as a potential treatment in HF. PMID:26483699

  4. Biomechanics of chiasmal compression: Sensitivity of the mechanical behaviors of nerve fibers to variations in material property and geometry

    Science.gov (United States)

    Wang, Xiaofei; Neely, Andrew J.; McIlwaine, Gawn G.; Lueck, Christian J.

    2016-05-01

    The mechanism of bitemporal hemianopia is still unclear. Previous research suggested that the nerve fiber packing pattern may contribute to the selective damage of nasal (crossed) nerve fibers. Numerical models were built using finite element modeling to study the biomechanics of optic nerve fibers. The sensitivity of the mechanical behaviors of the nerve fibers to variations of five parameters in the nerve fiber model were investigated using design of experiments (DOE). Results show that the crossing angle is a very significant factor that affects a wide range of responses of the model. The strain difference between the crossed and the uncrossed nerve fibers may account for the phenomenon of bitemporal hemianopia. This work also highlights the need for more accurate material properties of the tissues in the model and an improved understanding of the microstructure of the optic chiasm.

  5. Biodegradable conduit small gap tubulization for peripheral nerve mutilation: a substitute for traditional epineurial neurorrhaphy.

    Science.gov (United States)

    Zhang, Peixun; Han, Na; Wang, Tianbing; Xue, Feng; Kou, Yuhui; Wang, Yanhua; Yin, Xiaofeng; Lu, Laijin; Tian, Guanglei; Gong, Xu; Chen, Shanlin; Dang, Yu; Peng, Jianping; Jiang, Baoguo

    2013-01-01

    Nerve regeneration and re-innervation are usually difficult after peripheral nerve injury. Epineurium neurorrhaphy to recover the nerve continuity is the traditional choice of peripheral nerve mutilation without nerve defects, whereas the functional recovery remains quite unsatisfactory. Based on previous research in SD rats and Rhesus Monkeys, a multiple centers clinical trial about biodegradable conduit small gap tubulization for peripheral nerve mutilation to substitute traditional epineurial neurorrhaphy was carried out. Herein, the authors reviewed the literature that focused on peripheral nerve injury and possible clinical application, and confirmed the clinical possibilities of biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation. The biodegradable conduit small gap tubulization to substitute traditional epineurial neurorrhaphy for peripheral nerve mutilation may be a revolutionary innovation in peripheral nerve injury and repair field.

  6. Nerve fibers infiltrate the tumor microenvironment and are associated with nerve growth factor production and lymph node invasion in breast cancer.

    Science.gov (United States)

    Pundavela, Jay; Roselli, Severine; Faulkner, Sam; Attia, John; Scott, Rodney J; Thorne, Rick F; Forbes, John F; Bradshaw, Ralph A; Walker, Marjorie M; Jobling, Phillip; Hondermarck, Hubert

    2015-10-01

    Infiltration of the tumor microenvironment by nerve fibers is an understudied aspect of breast carcinogenesis. In this study, the presence of nerve fibers was investigated in a cohort of 369 primary breast cancers (ductal carcinomas in situ, invasive ductal and lobular carcinomas) by immunohistochemistry for the neuronal marker PGP9.5. Isolated nerve fibers (axons) were detected in 28% of invasive ductal carcinomas as compared to only 12% of invasive lobular carcinomas and 8% of ductal carcinomas in situ (p = 0.0003). In invasive breast cancers, the presence of nerve fibers was observed in 15% of lymph node negative tumors and 28% of lymph node positive tumors (p = 0.0031), indicating a relationship with the metastatic potential. In addition, there was an association between the presence of nerve fibers and the expression of nerve growth factor (NGF) in cancer cells (p = 0.0001). In vitro, breast cancer cells were able to induce neurite outgrowth in PC12 cells, and this neurotrophic activity was partially inhibited by anti-NGF blocking antibodies. In conclusion, infiltration by nerve fibers is a feature of the tumor microenvironment that is associated with aggressiveness and involves NGF production by cancer cells. The potential participation of nerve fibers in breast cancer progression needs to be further considered. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  7. Spike rate of multi-unit muscle sympathetic nerve fibers after catheter-based renal nerve ablation.

    Science.gov (United States)

    Tank, Jens; Heusser, Karsten; Brinkmann, Julia; Schmidt, Bernhard M; Menne, Jan; Bauersachs, Johann; Haller, Hermann; Diedrich, André; Jordan, Jens

    2015-10-01

    Patients with treatment-resistant arterial hypertension exhibited profound reductions in single sympathetic vasoconstrictor fiber firing rates after renal nerve ablation. In contrast, integrated multi-unit muscle sympathetic nerve activity (MSNA) changed little or not at all. We hypothesized that conventional MSNA analysis may have missed single fiber discharges, thus, obscuring sympathetic inhibition after renal denervation. We studied patients with difficult-to-control arterial hypertension (age 45-74 years) before, 6 (n = 11), and 12 months (n = 8) after renal nerve ablation. Electrocardiogram, respiration, brachial, and finger arterial blood pressure (BP), as well as the MSNA and raw MSNA signals were analyzed. We detected MSNA action-potential spikes using 2 stage kurtosis wavelet denoising techniques to assess mean, median, and maximum spike rates for each beat-to-beat interval. Supine heart rate and systolic BP did not change at 6 (ΔHR: -2 ± 3 bpm; ΔSBP: 2 ± 9 mm Hg) or at 12 months (ΔHR: -1 ± 3 mm Hg, ΔSBP: -1 ± 9 mm Hg) after renal nerve ablation. Mean burst frequency and mean spike frequency at baseline were 34 ± 3 bursts per minute and 8 ± 1 spikes per second. Both measurements did not change at 6 months (-1.4 ± 3.6 bursts/minute; -0.6 ± 1.4 spikes/second) or at 12 months (-2.5 ± 4.0 bursts/minute; -2.0 ± 1.6 spikes/second) after renal nerve ablation. After renal nerve ablation, BP decreased in 3 of 11 patients. BP and MSNA spike frequency changes were not correlated (slope = -0.06; P = .369). Spike rate analysis of multi-unit MSNA neurograms further suggests that profound sympathetic inhibition is not a consistent finding after renal nerve ablation. Copyright © 2015 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.

  8. Fibromyalgia Is Correlated with Retinal Nerve Fiber Layer Thinning.

    Science.gov (United States)

    Garcia-Martin, Elena; Garcia-Campayo, Javier; Puebla-Guedea, Marta; Ascaso, Francisco J; Roca, Miguel; Gutierrez-Ruiz, Fernando; Vilades, Elisa; Polo, Vicente; Larrosa, Jose M; Pablo, Luis E; Satue, Maria

    2016-01-01

    To investigate whether fibromyalgia induces axonal damage in the optic nerve that can be detected using optical coherence tomography (OCT), as the retinal nerve fiber layer (RNFL) is atrophied in patients with fibromyalgia compared with controls. Fibromyalgia patients (n = 116) and age-matched healthy controls (n = 144) were included in this observational and prospective cohort study. All subjects underwent visual acuity measurement and structural analysis of the RNFL using two OCT devices (Cirrus and Spectralis). Fibromyalgia patients were evaluated according to Giesecke's fibromyalgia subgroups, the Fibromyalgia Impact Questionnaire (FIQ), and the European Quality of Life-5 Dimensions (EQ5D) scale. We compared the differences between fibromyalgia patients and controls, and analyzed the correlations between OCT measurements, disease duration, fibromyalgia subgroups, severity, and quality of life. The impact on quality of life in fibromyalgia subgroups and in patients with different disease severity was also analyzed. A significant decrease in the RNFL was detected in fibromyalgia patients compared with controls using the two OCT devices: Cirrus OCT ganglion cell layer analysis registered a significant decrease in the minimum thickness of the inner plexiform layer (74.99±16.63 vs 79.36±3.38 μm, respectively; p = 0.023), nasal inferior, temporal inferior and temporal superior sectors (p = 0.040; 0.011 and 0.046 respectively). The Glaucoma application of the Spectralis OCT revealed thinning in the nasal, temporal inferior and temporal superior sectors (p = 0.009, 0.006, and 0.002 respectively) of fibromyalgia patients and the Axonal application in all sectors, except the nasal superior and temporal sectors. The odds ratio (OR) to estimate the size effect of FM in RNFL thickness was 1.39. RNFL atrophy was detected in patients with FIQ scores fibromyalgia (FIQ≥60) compared with patients with mild fibromyalgia (FIQfibromyalgia exhibited significant thinning in the

  9. Differential contribution of sodium channel subtypes to action potential generation in unmyelinated human C-type nerve fibers.

    Science.gov (United States)

    Lang, Philip M; Hilmer, Verena B; Grafe, Peter

    2007-09-01

    Multiple voltage-dependent sodium channels (Na(v)) contribute to action potentials and excitability of primary nociceptive neurons. The aim of the current study was to characterize subtypes of Na(v) that contribute to action potential generation in peripheral unmyelinated human C-type nerve fibers. Registration of C-fiber compound action potentials and determination of membrane threshold was performed by a computerized threshold tracking program. Nerve fibers were stimulated with a 1-ms current pulse either alone or after a small ramp current lasting 300 ms. Compound C-fiber action potentials elicited by supramaximal 1-ms current pulses were rather resistant to application of tetrodotoxin (30-90 nM). However, the same concentrations of tetrodotoxin strongly reduced the peak height and elevated membrane threshold of action potentials evoked at the end of a 300-ms current ramp. A similar effect was observed during application of lidocaine and mexiletine (50 microM each). These data indicate that more than one type of Na(v) contributes to the generation of action potentials in unmyelinated human C-type nerve fibers. The peak height of an action potential produced by a short electrical impulse is dependent on the activation of tetrodotoxin-resistant ion channels. In contrast, membrane threshold and action potential peak height at the end of a slow membrane depolarization are regulated by a subtype of Na(v) with high sensitivity to low concentrations of tetrodotoxin, lidocaine, and mexiletine. The electrophysiologic and pharmacologic characteristics may indicate the functional activity of the Na(v) 1.7 subtype of voltage-dependent sodium channels.

  10. Immunohistochemical localization of SNARE core proteins in intrapulpal and intradentinal nerve fibers of rat molar teeth.

    Science.gov (United States)

    Honma, Shiho; Kadono, Kohki; Kawano, Akiyo; Wakisaka, Satoshi

    2017-01-01

    The present study was designed to elucidate whether three soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) core proteins, syntaxin-1, synaptosomal-associated protein of 25kDa (SNAP-25), and vesicle-associated membrane protein-2 (VAMP-2), are present in the dental pulp of the rat molar at both the light and electron microscopic levels. Immunohistochemistry for protein gene product 9.5 (PGP 9.5), a pan-neuronal marker, syntaxin-1, SNAP-25, and VAMP-2 was performed on decalcified rat molars for light and electron microscopic analyses. Double-immunolabeling of PGP 9.5 and the SNARE core proteins, as well as combinations of the SNARE core proteins, was also carried out. PGP 9.5-immunoreactive nerve fibers ran toward the coronal region, ramified at the subodontoblast layer, and formed the subodontoblastic nerve plexus. Most nerve fibers penetrated the predentin and dentin along the dentinal tubules. Most, if not all, nerve fibers displayed immunoreactivity for syntaxin-1, SNAP-25, and VAMP-2. Immunoelectron microscopic analyses confirmed the presence of immunoreactivity for the SNARE core proteins within the intradental axonal elements. The present findings suggest that, since SNARE core proteins participate in the docking and exocytosis of synaptic vesicles in the central nervous system, they may contribute to vesicle exocytosis from the dental nerve fibers even though there are no apparent synapses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Retinal nerve fiber layer thickness is associated with lesion length in acute optic neuritis

    DEFF Research Database (Denmark)

    Kallenbach, K; Simonsen, Helle Juhl; Sander, B

    2010-01-01

    coherence tomography and the length and location of the inflammatory optic nerve lesion were evaluated using MRI. RESULTS: Ophthalmoscopically, 34% of the patients had papillitis. The retinal nerve fiber layer in affected eyes (mean 123.1 microm) was higher during the acute phase than that of fellow eyes...... (mean 98.1 microm, p lesion (p = 0.0002), but not to the location of the optic nerve lesions (p = 0.72). CONCLUSIONS: In this study of the acute phase of optic...... neuritis, the degree of optic nerve head edema depended upon the extent of the optic nerve lesion, but not on its location. This suggests that factors other than inflammation, such as compromised venous drainage, vascular leakage, impaired axonal transport, and other mechanisms, are involved...

  12. Sound and vibration sensitivity of VIIIth nerve fibers in the grassfrog, Rana temporaria

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B

    1996-01-01

    We have studied the sound and vibration sensitivity of 164 amphibian papilla fibers in the VIIIth nerve of the grassfrog, Rana temporaria. The VIIIth nerve was exposed using a dorsal approach. The frogs were placed in a natural sitting posture and stimulated by free-field sound. Furthermore...... at the threshold for sound. However, these results are only valid for the present physical configuration of the setup and the high vibration-sensitivities of the fibers warrant caution whenever the auditory fibers are stimulated with free-field sound. Thus, the experiments suggest that the low-frequency sound......, the animals were stimulated with dorso-ventral vibrations, and the sound-induced vertical vibrations in the setup could be canceled by emitting vibrations in antiphase from the vibration exciter. All low-frequency fibers responded to both sound and vibration with sound thresholds from 23 dB SPL and vibration...

  13. Structural and functional assessment of skin nerve fibres in small-fibre pathology.

    Science.gov (United States)

    Karlsson, P; Nyengaard, J R; Polydefkis, M; Jensen, T S

    2015-09-01

    Damage to nociceptor nerve fibres may give rise to peripheral neuropathies, some of which are pain free and some are painful. A hallmark of many peripheral neuropathies is the loss of small nerve fibres in the epidermis, a condition called small-fibre neuropathy (SFN) when it is predominantly the small nerve fibres that are damaged. Historically, SFN has been very difficult to diagnose as clinical examination and nerve conduction studies mainly detect large nerve fibres, and quantitative sensory testing is not sensitive enough to detect small changes in small nerve fibres. However, taking a 3-mm punch skin biopsy from the distal leg and quantification of the nerve fibre density has proven to be a useful method to diagnose SFN. However, the correlation between the nerve fibre loss and other test results varies greatly. Recent studies have shown that it is possible not only to extract information about the nerve fibre density from the biopsies but also to get an estimation of the nerve fibre length density using stereology, quantify sweat gland innervation and detect morphological changes such as axonal swelling, all of which may be additional parameters indicating diseased small fibres relating to symptoms reported by the patients. In this review, we focus on available tests to assess structure and function of the small nerve fibres, and summarize recent advances that have provided new possibilities to more specifically relate structural findings with symptoms and function in patients with SFN. © 2014 European Pain Federation - EFIC®

  14. Quantification of small fiber pathology in patients with sarcoidosis and chronic pain using cornea confocal microscopy and skin biopsies

    Directory of Open Access Journals (Sweden)

    Oudejans LCJ

    2017-08-01

    Full Text Available Linda CJ Oudejans,1 Marieke Niesters,1 Michael Brines,2 Albert Dahan,1 Monique van Velzen1 1Department of Anesthesiology, Leiden University Medical Center, Leiden, the Netherlands; 2Araim Pharmaceuticals, Inc., Tarrytown, NY, USA Abstract: Small fiber pathology with concomitant chronic neuropathic pain is a common complication of sarcoidosis. The gold standard of diagnosis of small fiber neuropathy (SFN is the quantification of small nerve fibers in skin biopsies in combination with patient history and psychophysical tests; a new technique is the quantification of small nerve fibers in the cornea using cornea confocal microscopy (CCM. Here, we studied small fiber morphology in sarcoidosis patients with neuropathic pain using skin biopsies, CCM, and quantitative sensory testing (QST. Our aim was to construct specific phenotypes of neuropathic pain in sarcoidosis. Fifty-eight patients with a confirmed diagnosis of sarcoidosis and with moderate-to-severe neuropathic pain were tested. Decreased intraepidermal nerve fiber density (IENFD from skin biopsies was found in 28% of patients, and CCM abnormalities were observed in 45% of patients. There was no correlation between CCM and IENFD abnormalities. Eighty-three percent of patients had abnormal thermal detection thresholds, a sign of small fiber dysfunction. Based on the presence or absence of abnormalities in IENFD and CCM, four distinct phenotypes were identified with a distinct homogeneous pattern of somatosensory symptoms. We argue that these distinct phenotypes have a similar mechanistic construct with specific phenotype-specific treatment options. Additionally, our data suggest the presence of patients with length- and nonlength-dependent SFN within this population of sarcoidosis patients. Keywords: chronic pain, sarcoidosis, small fiber neuropathy

  15. Peripapillary retinal nerve fiber layer and choroidal thickness in cirrhosis patients

    Directory of Open Access Journals (Sweden)

    M.Orcun Akdemir

    2015-12-01

    Full Text Available ABSTRACT Purpose: To evaluate the effect of cirrhosis on peripapillary retinal nerve fiber layer and choroidal thickness with enhanced depth imaging optical coherence tomography. Methods: This cross sectional, single center study was undertaken at Bulent Ecevit University Ophthalmology department with the participation of internal medicine, Gastroenterology department. Patients who were treated with the diagnosis of cirrhosis (n=75 were examined in the ophthalmology clinic. Age and sex matched patients (n=50 who were healthy and met the inclusion, exclusion criteria were included in the study. Complete ophthalmological examination included visual acuity with Snellen chart, intraocular pressure measurement with applanation tonometry, biomicroscopy of anterior and posterior segments, gonioscopy, axial length measurement, visual field examination, peripapillary retinal nerve fiber layer, central macular and subfoveal choroidal thickness measurements. Results: The difference between intraocular pressure values was not statistically significant between cirrhosis and control group (p=0.843. However, mean peripapillary retinal nerve fiber layer thickness was significantly thinner in cirrhosis group in all regions (p<0.001 and subfoveal choroidal thickness was significantly thinner in cirrhosis group also (p<0.001. Moreover, central macular thickness of cirrhosis group was significantly thicker than the control group (p=0.001. Conclusion: Peripapillary retinal nerve fiber layer and subfoveal choroidal thickness was significantly thinner in cirrhosis patients.

  16. Association of Myelinated Retinal Nerve Fibers With Acquired Mulberry Retinal Astrocytoma: Coincidental or Relational?

    Science.gov (United States)

    Bypareddy, Ravi; Takkar, Brijesh; Lohchab, Monica; Azad, Shorya Vardhan; Chawla, Rohan

    2017-05-01

    Retinal astrocytoma is an important ocular finding for diagnosis of tuberous sclerosis complex and is also an association of neurofibromatosis. The authors present findings of a case of acquired astrocytoma associated with myelinated retinal nerve fibers. The authors also discuss the images and possible cause-effect relationship between them. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:441-442.]. Copyright 2017, SLACK Incorporated.

  17. Reduction in Retinal Nerve Fiber Layer Thickness in Young Adults with Autism Spectrum Disorders

    Science.gov (United States)

    Emberti Gialloreti, Leonardo; Pardini, Matteo; Benassi, Francesca; Marciano, Sara; Amore, Mario; Mutolo, Maria Giulia; Porfirio, Maria Cristina; Curatolo, Paolo

    2014-01-01

    Recent years have seen an increase in the use of retinal nerve fiber layer (RNFL) evaluation as an easy-to-use, reproducible, proxy-measure of brain structural abnormalities. Here, we evaluated RNFL thickness in a group of subjects with high functioning autism (HFA) or with Asperger Syndrome (AS) to its potential as a tool to study autism…

  18. Retinal nerve fiber layer analysis: Relationship between optical coherence tomography and red-free photography

    NARCIS (Netherlands)

    Soliman, Mohamed A. E.; van den Berg, Thomas J. T. P.; Ismaeil, Al-Araby A.; de Jong, Leo A. M. S.; de Smet, Marc D.

    2002-01-01

    PURPOSE: Comparison of retinal nerve fiber layer (RNFL) thickness measurements using optical coherence tomography (OCT) to the clinical standard red-free photography (evaluated semiquantitatively), in relation to functional visual field damage in primary open-angle glaucoma (POAG) patients, ocular

  19. Ultra Small Integrated Optical Fiber Sensing System

    Directory of Open Access Journals (Sweden)

    Peter Van Daele

    2012-09-01

    Full Text Available This paper introduces a revolutionary way to interrogate optical fiber sensors based on fiber Bragg gratings (FBGs and to integrate the necessary driving optoelectronic components with the sensor elements. Low-cost optoelectronic chips are used to interrogate the optical fibers, creating a portable dynamic sensing system as an alternative for the traditionally bulky and expensive fiber sensor interrogation units. The possibility to embed these laser and detector chips is demonstrated resulting in an ultra thin flexible optoelectronic package of only 40 μm, provided with an integrated planar fiber pigtail. The result is a fully embedded flexible sensing system with a thickness of only 1 mm, based on a single Vertical-Cavity Surface-Emitting Laser (VCSEL, fiber sensor and photodetector chip. Temperature, strain and electrodynamic shaking tests have been performed on our system, not limited to static read-out measurements but dynamically reconstructing full spectral information datasets.

  20. Temporal retinal nerve fiber loss in patients with spinocerebellar ataxia type 1.

    Directory of Open Access Journals (Sweden)

    Sarah Stricker

    Full Text Available BACKGROUND: Autosomal dominant spinocerebellar ataxia type 1 is an adult onset progressive disorder with well characterized neurodegeneration in the cerebellum and brainstem. Beyond brain atrophy, few data exist concerning retinal and optic nerve involvement. OBJECTIVE: To evaluate retinal changes in SCA1 patients compared to age and gender matched healthy controls. METHODOLOGY/PRINCIPAL FINDINGS: Nine patients with SCA1 were prospectively recruited from the ataxia clinic and were compared to nine age and gender matched healthy controls. Both cohorts received assessment of visually evoked potentials and eye examination by optical coherence tomography to determine retinal nerve fiber layer thickness and total macular volume. While no differences were found in visually evoked potentials, SCA1 patients showed a significant reduction of mean retinal nerve fiber layer thickness (RNFLT compared to healthy controls (84±13 µm vs. 97±8 µm, p = 0.004. Temporal areas showed the most prominent RNFLT reduction with high statistical significances (temporal-inferior: p<0.001, temporal: p<0.001, temporal-superior: p = 0.005 whereas RNFLT in nasal areas was in the range of the control group. From six SCA1 patients an additional macular scan was obtained. The comparison to the corresponding healthy control showed a slight but not significant reduction in TMV (8.22±0.68 mm(3 vs. 8.61±0.41 mm(3, p = 0.15. CONCLUSION: In SCA1 patients, we found evidence for degeneration of retinal nerve fibers. The temporal focus of the observed retinal nerve fiber layer reduction suggests an involvement of the papillo-macular bundle which resembles pathology found in toxic or mitochondrial optic nerve disease such as Leber's hereditary optic neuropathy (LHON or dominant optic atrophy (DOA.

  1. Speckle reduction during all-fiber common-path optical coherence tomography of the cavernous nerves

    Science.gov (United States)

    Chitchian, Shahab; Fiddy, Michael; Fried, Nathaniel M.

    2009-02-01

    Improvements in identification, imaging, and visualization of the cavernous nerves during prostate cancer surgery, which are responsible for erectile function, may improve nerve preservation and postoperative sexual potency. In this study, we use a rat prostate, ex vivo, to evaluate the feasibility of optical coherence tomography (OCT) as a diagnostic tool for real-time imaging and identification of the cavernous nerves. A novel OCT system based on an all single-mode fiber common-path interferometer-based scanning system is used for this purpose. A wavelet shrinkage denoising technique using Stein's unbiased risk estimator (SURE) algorithm to calculate a data-adaptive threshold is implemented for speckle noise reduction in the OCT image. The signal-to-noise ratio (SNR) was improved by 9 dB and the image quality metrics of the cavernous nerves also improved significantly.

  2. Basic response characteristics of auditory nerve fibers in the grassfrog (Rana temporaria)

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Jørgensen, M B; Kanneworff, M

    1998-01-01

    Responses to free-field sound of 401 fibers from the VIIIth nerve of the grassfrog, Rana temporaria, are described. The spontaneous activities of the fibers ranged from 0 to 75 spikes/s, showing only weak correlation with frequency or sensitivity of the fibers. The highest spontaneous activities...... were approximately twice as high as reported previously for frogs. Best frequencies ranged from 100 to 1600 Hz and thresholds ranged from 21 to 80 dB SPL. The median dynamic range was 20 dB and the slopes of the rate-level curves ranged from 5 to 20 spikes/(s-dB). Most of the units showed post......-excitatory suppression (PS) of their spontaneous activity. The duration of PS increased with sound level, also in fibers showing a decrease in firing rate at high intensities. Most fibers showing one-tone suppression did not show PS at their best suppression frequencies. Strong suppression was observed also in very...

  3. Study of nerve fibers nature reinforcing duodenal contractions by electrical stimulation of sympathetic nerve

    Directory of Open Access Journals (Sweden)

    Sveshnikov D.S.

    2011-09-01

    Full Text Available The subject of the article is to investigate the mechanism of increased reactions by electrical stimulation of the sympathetic nerve. Materials and methods: Experiments on dogs have shown that stimulant reactions during blockade of a-adrenergic by phentolamine and (3-adrenergic receptors with propranolol were completely eliminated by lizer-gol —the blocker of 5-HT12-receptors. Results: Infusion of lizergol did not influence on duodenal motor activity and the function of the vagus nerve. Conclusion: Effector neuron is found out to be serotonergic and its action is provided by 5-HT1 2 receptors

  4. Nerve fibers and endometriotic lesions: partners in crime in inflicting pains in women with endometriosis.

    Science.gov (United States)

    Yan, Dingmin; Liu, Xishi; Guo, Sun-Wei

    2017-02-01

    One of major objectives in treating endometriosis is to alleviate pain since dysmenorrhea and other types of pain top the list of complaints from women with endometriosis who seek medical attention. Indeed, endometriosis-associated pain (EAP) is the most debilitating of the disease that negatively impacts on the quality of life in affected women, contributing significantly to the burden of disease and adding to the substantial personal and societal costs. Unfortunately, the mechanisms underlying the EAP are still poorly understood. In the last two decades, one active research field in endometriosis is the investigation on the distribution and genesis of nerve fibers in eutopic and ectopic endometrium, and the attempt to use endometrial nerve fiber density for diagnostic purpose. Since EAP presumably starts with the terminal sensory nerves, in or around endometriotic lesions, that transduce noxious mediators to the central nervous system (CNS) which ultimately perceives pain, this field of research holds the promise to elucidate the molecular mechanisms underlying the EAP, thus opening new avenues for novel diagnostics and therapeutics. In this review, we shall first briefly provide some basic facts on nerve fibers, and then provide an overview of some major findings in this filed while also note some conflicting results and expose areas in need of further research. We point out that since recently accumulated evidence suggests that endometriotic lesions are wounds undergoing repeated tissue injury and repair, the relationship between endometriotic lesions and nerve fibers is not simply unidirectional, i.e. lesions promote hyperinnervations. Rather, it is bidirectional, i.e. endometriotic lesions and nerve fibers engage active cross-talks, resulting in the development of endometriosis and pain. That is, nerve fibers and endometriotic lesions are actually partners in crime in inflicting pains in women with endometriosis, aided and abetted possibly by other culprits

  5. Three-dimensional Imaging and Analysis of Mitochondria within Human Intraepidermal Nerve Fibers.

    Science.gov (United States)

    Hamid, Hussein S; Hayes, John M; Feldman, Eva L; Lentz, Stephen I

    2017-09-29

    The goal of this protocol is to study mitochondria within intraepidermal nerve fibers. Therefore, 3D imaging and analysis techniques were developed to isolate nerve-specific mitochondria and evaluate disease-induced alterations of mitochondria in the distal tip of sensory nerves. The protocol combines fluorescence immunohistochemistry, confocal microscopy and 3D image analysis techniques to visualize and quantify nerve-specific mitochondria. Detailed parameters are defined throughout the procedures in order to provide a concrete example of how to use these techniques to isolate nerve-specific mitochondria. Antibodies were used to label nerve and mitochondrial signals within tissue sections of skin punch biopsies, which was followed by indirect immunofluorescence to visualize nerves and mitochondria with a green and red fluorescent signal respectively. Z-series images were acquired with confocal microscopy and 3D analysis software was used to process and analyze the signals. It is not necessary to follow the exact parameters described within, but it is important to be consistent with the ones chosen throughout the staining, acquisition and analysis steps. The strength of this protocol is that it is applicable to a wide variety of circumstances where one fluorescent signal is used to isolate other signals that would otherwise be impossible to study alone.

  6. Interoperator variability in images obtained by laser polarimetry of the nerve fiber layer.

    Science.gov (United States)

    H Swanson, W; R Lynn, J; Fellman, R L; Starita, R J; Schumann, S P; Nusinowitz, S

    1995-12-01

    To study operated-related variability in images obtained by laser polarimetry of the nerve fiber layer, a new imaging technique that attempts to estimate thickness of the nerve fiber layer by using the fact that it is birefringent. Measurements were made using a commercial device, the Nerve Fiber Analyzer (Laser Diagnostic Technologies, San Diego, CA), which uses a dedicated scanning laser ophthalmoscope to produce a retardation map of the retina adjacent to the optic nerve head. Four trained operators tested 11 subjects twice each, resulting in 88 images. Standard circles were placed around the optic disk for analysis. We analyzed five indices computed from these images: mean thickness in each of four quadrants and mean thickness under the entire circle. Repeated-measures analyses of variance showed significant effects of operator for four of these indices. Mean values for a given index varied by 11-14 muUm across operators, and the maximum difference across operators was approximately 22 of the mean value across subjects. The clinical usefulness of the device will be limited until it has been shown that new modifications successfully reduce interoperator variability.

  7. The Fine Structure of Nerve Cells and Fibers, Neuroglia, and Sheaths of the Ganglion Chain in the Cockroach (Periplaneta americana)

    Science.gov (United States)

    Hess, Arthur

    1958-01-01

    The abdominal nerve cord of Periplaneta americana was studied utilizing light and electron microscopes. In the nerve cells, delicate granules, similar to those probably responsible for cytoplasmic basophilia, are evenly distributed in "dark" cells and clumped in "light" cells. Neuroglial cells are stained metachromatically by cresyl violet. The neuroglial cells have many processes which ramify extensively and are enmeshed to form overlapping layers. These imbricated processes ensheath the nerve cells; the inner layer of the sheath penetrates into the neuron and is responsible for the appearance of the trophospongium of Holmgren. Nerve fibers are embedded within glial cells and surrounded by extensions of the plasma membrane similar to mesaxons. Depending on their size, two or several nerve fibers may share a single glial cell. Nerve fibers near their terminations on other nerve fibers contain particles and numerous, large mitochondria. The ganglion is ensheathed by a thick feltwork of connective tissue and perilemmal cells. The abdominal connective has a thinner connective tissue sheath which is without perilemmal cells. The nerve fibers and sheaths in the connective become thinner as they pass through ganglia. PMID:13610937

  8. Galanin - Immunoreactive Nerve Fibers in the Mucosal Layer of the Canine Gastrointestinal Tract During Inflammatory Bowel Disease

    Directory of Open Access Journals (Sweden)

    Rychlik Andrzej

    2015-04-01

    Full Text Available The effect of inflammatory bowel disease (IBD on the density of galanin - immunoreactive (GAL-IR nerve fibers was determined in the mucosa of canine duodenum, jejunum, and descending colon. Fiber density was evaluated by a single immunofluorescence method in biopsy specimens obtained from healthy dogs and patients with variable severity of the disease. The density of GAL-IR nerve fibers was determined by the semi-quantitative method by counting fibers in the field of view (0.l mm2. Fiber density was higher in dogs with moderate and severe IBD than in healthy animals. The results of the study suggest that GAL present in intestinal nerve fibers could play a role in the pathogenesis and development of canine IBD.

  9. The histopathological evaluation of small fiber neuropathy in patients with vitamin B12 deficiency.

    Science.gov (United States)

    Güneş, Hafize Nalan; Bekircan-Kurt, Can Ebru; Tan, Ersin; Erdem-Özdamar, Sevim

    2017-10-19

    Small fiber neuropathy (SFN), due to loss of A-delta and unmyelinated C fibers, is a cause of neuropathic pain. Although the patients with vitamin B12 deficiency are included in SFN studies in the literature, there is no histopathological study investigating the small fiber loss solely in patients with vitamin B12 deficiency. In this pilot study, we aim to demonstrate the intraepidermal nerve fiber density (IENFD) in skin punch biopsy of patients with vitamin B12 deficiency. Ten patients with vitamin B12 deficiency suffering from neuropathic pain and as control group ten patients with vitamin B12 deficiency without neuropathic pain were included. Neurological examination, electrophysiological evaluation, and DN4 questionnaire were performed. Subsequently, skin punch biopsy 10 cm above the lateral malleolus was done. The biopsy samples were stained with PGP9.5 antibody, and IENFD was determined. IENFD was low in two groups compared to their age normative values. The median of IENFD was 3.345 (1.12-5.32) in patients with neuropathic pain and 6. 20 (4.6-9.8) in controls (p B12 deficiency causes symptomatic as well as asymptomatic small fiber loss like diabetes mellitus.

  10. Neuroprotective effect of erythropoietin against pressure ulcer in a mouse model of small fiber neuropathy.

    Directory of Open Access Journals (Sweden)

    Aurore Danigo

    Full Text Available An increased risk of skin pressure ulcers (PUs is common in patients with sensory neuropathies, including those caused by diabetes mellitus. Recombinant human erythropoietin (rhEPO has been shown to protect the skin against PUs developed in animal models of long-term diabetes. The aim of this work was to determine whether rhEPO could prevent PU formation in a mouse model of drug-induced SFN. Functional SFN was induced by systemic injection of resiniferatoxin (RTX, 50 µg/kg, i.p.. RhEPO (3000 UI/kg, i.p. was given the day before RTX injection and then every other day. Seven days after RTX administration, PUs were induced by applying two magnetic plates on the dorsal skin. RTX-treated mice expressed thermal and mechanical hypoalgesia and showed calcitonin gene-related peptide (CGRP and substance P (SP depletion without nerve degeneration or vascular dysfunction. RTX mice developed significantly larger stage 2 PUs than Vehicle mice. RhEPO prevented thermal and mechanical hypoalgesia and neuropeptide depletion in small nerve fibers. RhEPO increased hematocrit and altered endothelium-dependent vasodilatation without any effect on PU formation in Vehicle mice. The characteristics of PUs in RTX mice treated with rhEPO and Vehicle mice were found similar. In conclusion, RTX appeared to increased PU development through depletion of CGRP and SP in small nerve fibers, whereas systemic rhEPO treatment had beneficial effect on peptidergic nerve fibers and restored skin protective capacities against ischemic pressure. Our findings support the evaluation of rhEPO and/or its non-hematopoietic analogs in preventing to prevent PUs in patients with SFN.

  11. Imaging of the optic disc and retinal nerve fiber layer: the effects of age, optic disc area, refractive error, and gender

    Science.gov (United States)

    Bowd, Christopher; Zangwill, Linda M.; Blumenthal, Eytan Z.; Vasile, Cristiana; Boehm, Andreas G.; Gokhale, Parag A.; Mohammadi, Kourosh; Amini, Payam; Sankary, Timothy M.; Weinreb, Robert N.

    2002-01-01

    We cross-sectionally examined the relationship between age, optic disc area, refraction, and gender and optic disc topography and retinal nerve fiber layer (RNFL) measurements, using optical imaging techniques. One eye from each of 155 Caucasian subjects (age range 23.0-80.8 y) without ocular pathology was included. Measurements were obtained by using the Heidelberg Retina Tomography (HRT), the GDx Nerve Fiber Analyzer, and the Optical Coherence Tomograph (OCT). The effects of age were small (R2associated with most HRT parameters and isolated GDx and OCT parameters. Refraction and gender were not significantly associated with any optic disc or RNFL parameters. Although effects of age on the optic disc and RNFL are small, they should be considered in monitoring ocular disease. Optic disc area should be considered when cross-sectionally evaluating disc topography and, to a lesser extent, RNFL thickness.

  12. Fast negative feedback enables mammalian auditory nerve fibers to encode a wide dynamic range of sound intensities.

    Directory of Open Access Journals (Sweden)

    Mark Ospeck

    Full Text Available Mammalian auditory nerve fibers (ANF are remarkable for being able to encode a 40 dB, or hundred fold, range of sound pressure levels into their firing rate. Most of the fibers are very sensitive and raise their quiescent spike rate by a small amount for a faint sound at auditory threshold. Then as the sound intensity is increased, they slowly increase their spike rate, with some fibers going up as high as ∼300 Hz. In this way mammals are able to combine sensitivity and wide dynamic range. They are also able to discern sounds embedded within background noise. ANF receive efferent feedback, which suggests that the fibers are readjusted according to the background noise in order to maximize the information content of their auditory spike trains. Inner hair cells activate currents in the unmyelinated distal dendrites of ANF where sound intensity is rate-coded into action potentials. We model this spike generator compartment as an attenuator that employs fast negative feedback. Input current induces rapid and proportional leak currents. This way ANF are able to have a linear frequency to input current (f-I curve that has a wide dynamic range. The ANF spike generator remains very sensitive to threshold currents, but efferent feedback is able to lower its gain in response to noise.

  13. BASAL CELL NEVUS SYNDROME PRESENTING AS EPIRETINAL MEMBRANE AND MYELINATED NERVE FIBER LAYER.

    Science.gov (United States)

    Farley, Nathan D; Sassalos, Thérèse M; Ober, Michael D

    2017-01-01

    To report a case of epiretinal membrane and myelinated nerve fiber layer, which preceded the diagnosis of basal cell nevus syndrome, in a young girl. Observational case report. A 12-year-old girl was referred for an asymptomatic epiretinal membrane. Examination revealed epiretinal membrane in the right eye without posterior vitreous separation or vitreous abnormality and bilateral myelinated nerve fiber layer. Subsequent workup yielded pathologic diagnosis of multiple skin basal cell carcinoma and odontogenic keratocysts in the jaw. Genetic testing revealed a frameshift mutation in the PTCH1 gene. Basal cell nevus syndrome is a rare autosomal dominant disease that affects multiple organ systems, including the eyes. Recognition of common ocular findings in children with basal cell nevus syndrome can lead to systemic diagnosis. Early diagnosis is critical to initiate early screening for known neoplastic associations and lifelong minimization of sun exposure to reduce the incidence and severity of basal cell carcinoma.

  14. Reproducibility of peripapillary retinal nerve fiber layer thickness measurements using Spectral Domain OCT in Brazilian patients

    Directory of Open Access Journals (Sweden)

    Daniela Araújo Toscano

    2012-10-01

    Full Text Available PURPOSE: To evaluate the reproducibility of peripapillary retinal nerve fiber layer (RNFL thickness measurements in normal eyes and eyes with glaucoma using spectral domain optical coherence tomography (SDOCT. METHODS: One eye of 79 normal and 72 glaucoma patients was analyzed. All patients underwent a complete ophthalmological examination, including visual acuity testing; intraocular pressure, slit-lamp examination, indirect ophthalmoscopy; and the glaucoma group underwent achromatic perimetry with the 24-2 SITA Fast Humphrey Field Analyzer. All patients' eyes were scanned using the spectral domain optical coherence tomography - Spectralis® and one of them was chosen randomly. Three consecutive circular B-scan centered at the optic disc were performed in one visit. RESULTS: The intraclass correlation coefficient (ICC, coefficient of variation and test-retest variability for the mean retinal nerve fiber layer thickness were respectively: 0.94, 2.56% and 4.85 µm for the normal group and 0.93, 4.65% and 6.61 µm for the glaucomatous group. The intraclass correlation coefficient for retinal nerve fiber layer thickness in all quadrants were all excellent in both groups, with the superior quadrant having the highest ICCs (0.964 in glaucomatous eyes and nasal quadrant measurements having the lowest (0.800, but still excellent in eyes without glaucoma. The coefficient of variation was between 2.56% - 8.74% and between 4.65% - 11.44% in normal and glaucomatous group respectively. The test-retest variability was between 4.85 µm and 11.51 µm in the normal group and between 6.61 µm and 14.24 µm in the glaucomatous group. The measurements in glaucomatous eyes were more variable than normal eyes. CONCLUSIONS: Spectral domain optical coherence tomography showed excellent reproducibility with regard to retinal nerve fiber layer thickness measurements in normal and glaucomatous eyes.

  15. Dopamine release from serotonergic nerve fibers is reduced in L-DOPA-induced dyskinesia

    OpenAIRE

    Nevalainen, Nina; af Bjerkén, Sara; Lundblad, Martin; Gerhardt, Greg A.; Strömberg, Ingrid

    2011-01-01

    L-DOPA (3,4-dihydroxyphenyl-L-alanine) is the most commonly used treatment for symptomatic control in patients with Parkinson’s disease. Unfortunately, most patients develop severe side effects, such as dyskinesia, upon chronic L-DOPA treatment. The patophysiology of dyskinesia is unclear, however, involvement of serotonergic nerve fibers in converting L-DOPA to dopamine has been suggested. Therefore, potassium-evoked dopamine release was studied after local application of L-DOPA in the stria...

  16. Afferent fibers of the pudendal nerve modulate sympathetic neurons controlling the bladder neck.

    Science.gov (United States)

    Reitz, André; Schmid, Daniel M; Curt, Armin; Knapp, Peter A; Schurch, Brigitte

    2003-01-01

    Pudendal nerve stimulation is known to have a potential modulative effect on bladder function. However, even if its efficiency has been established for various neurogenic and non-neurogenic bladder dysfunctions, the underlying neuronal mechanism, and the involved pathways in humans remain unknown. In this prospective study we focused on the effects of pudendal nerve stimulation in complete spinal cord injured patients to identify neuromodulative processes that occur on spinal level. Twenty complete spinal male presenting with upper motor neuron lesion and neurogenic incontinence underwent pudendal nerve stimulation. Bladder, bladder neck (BN), and external urethral sphincter (EUS) pressures were continuously recorded with a three channel microtip pressure transducer catheter. Fifty six pudendal stimulations using biphasic rectangular impulses (0.2 ms, 10 Hz) with intensities up to 100 mA were applied to the dorsal penile nerve. In six patients, 18 stimulations were repeated after intravenous (i.v.) administration of 7 mg phentolamine. Mean BN and EUS pressure increased during stimulation significantly (P stimulation significantly (P nerve stimulation evoked somatic responses in the EUS and autonomic responses in the smooth muscle sphincter controlling the BN. Longer latencies of the BN responses and the sensitivity to the alpha-blocking agent phentolamine suggest that sympathetic alpha-adrenergic fibers are involved. Somatic afferent fibers of the pudendal nerve are supposed to project on sympathetic thoracolumbar neurons to the BN and modulate their function. This neuromodulative effect works exclusively at the spinal level and appears to be at least partly responsible for BN competence and at least continence. Copyright 2003 Wiley-Liss, Inc.

  17. Morphometric analysis of the fiber populations of the rat sciatic nerve, its spinal roots, and its major branches

    NARCIS (Netherlands)

    Prodanov, D.P.; Feierabend, H.K.P.

    2007-01-01

    Correspondence between the nerve composition and the functional characteristics of its fiber populations is not always evident. To investigate such correspondence and to give a systematic picture of the morphology of the rat hind limb nerves, extensive morphometric study was performed on the sciatic

  18. Changes of nitric oxide synthase-containing nerve fibers and parameters for oxidative stress after unilateral cavernous nerve resection or manuplation in rat penis.

    Science.gov (United States)

    Ozkara, Hamdi; Alan, Cabir; Atukeren, Pinar; Uyaner, Ilhan; Demirci, Cihan; Gümüştaş, M Koray; Alici, Bulent

    2006-06-30

    After pelvic surgeries such as radical prostatectomy, two major complications--urinary incontinence and erectile dysfunction (ED) may occur. Etiologies for ED are multiple pathologic mediators/systems. Oxidative stress, which is known to be induced after surgical trauma, could be a cause of ED. The purposes of in this study are to investigate the effect of unilateral manipulation/ dissection and resection of the cavernous nerve (neurotomy) to NOS (nitric oxide synthase)-containing nerve fibers and pressure after electro stimulation in rat corpus cavernosum, and to determine whether these procedures would produce oxidative stress within rat cavernous tissue 3 weeks and 6 months after the operation. Male rats were divided into 5 groups. Rats in groups 1 and 2 underwent unilateral cavernous nerve manipulation and sacrificed 3 weeks and 6 months after the operation, respectively. Rats in groups 3 and 4 underwent unilateral neurotomy of a 5-mm. segment of the cavernous nerve, and they were sacrificed 3 weeks and 6 months after nerve ablation, respectively. Group 5 rats were control animals for biochemical analysis. Intracavernous pressure following electro stimulation reduced is significantly 3 weeks after unilateral resection, as compared to that of the manipulated nerve (P cavernous nerve manipulation or resection produced oxidative stress within rat corpus cavernosum. Oxidative stress was more prominent 3 weeks after unilateral neurotomy (P cavernous nerve (P cavernous nerve caused more prominent oxidative stress than in the manipulation group. This study suggested, that unilateral cavernous neurotomy caused a decrease of intra cavernous pressure and NOS fibers in rat corpus cavernosum, and they recovered 6 months after neurotomy. Our data also provided evidence that neurotomy and manipulation of the cavernous nerve caused oxidative stress in rat corpus cavernosum and that oxidative stress was more prominent in the nerve resection group.

  19. A simple method for fabrication of electrospun fibers with controlled degree of alignment having potential for nerve regeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Vimal, Sunil Kumar; Ahamad, Nadim; Katti, Dhirendra S., E-mail: dsk@iitk.ac.in

    2016-06-01

    In peripheral nerve injuries where direct suturing of nerve endings is not feasible, nerve regeneration has been facilitated through the use of artificially aligned fibrous scaffolds that provide directional growth of neurons to bridge the gap. The degree of fiber alignment is crucial and can impact the directionality of cells in a fibrous scaffold. While there have been multiple approaches that have been used for controlling fiber alignment, however, they have been associated with a compromised control on other properties, such as diameter, morphology, curvature, and topology of fibers. Therefore, the present study demonstrates a modified electrospinning set-up, that enabled fabrication of electrospun fibers with controlled degree of alignment from non-aligned (NA), moderately aligned (MA, 75%) to highly aligned (HA, 95%) sub-micron fibers while keeping other physical properties unchanged. The results demonstrate that the aligned fibers (MA and HA) facilitated directional growth of human astrocytoma cells (U373), wherein the aspect ratio of cells was found to increase with an increase in degree of fibers alignment. In contrast to NA and MA fibers, the HA fibers showed improved contact guidance to U373 cells that was demonstrated by a significantly higher cell aspect ratio and nuclear aspect ratio. In conclusion, the present study demonstrated a modified electrospinning setup to fabricate differentially aligned fibrous scaffolds with the HA fibers showing potential for use in neural tissue engineering. - Highlights: • Modified electrospinning set-up for fabrication of fibers with controlled alignment • Three parameter-based control on the degree of alignment of fibers • The aligned fibers enhanced cell elongation and cell-cell contact. • The aligned fibers show potential for use in nerve regeneration.

  20. Human amniotic epithelial cells express specific markers of nerve cells and migrate along the nerve fibers in the corpus callosum.

    Science.gov (United States)

    Wu, Zhiyuan; Hui, Guozhen; Lu, Yi; Liu, Tianjin; Huang, Qin; Guo, Lihe

    2012-01-05

    Human amniotic epithelial cells were isolated from a piece of fresh amnion. Using immunocytochemical methods, we investigated the expression of neuronal phenotypes (microtubule-associated protein-2, glial fibrillary acidic protein and nestin) in human amniotic epithelial cells. The conditioned medium of human amniotic epithelial cells promoted the growth and proliferation of rat glial cells cultured in vitro, and this effect was dose-dependent. Human amniotic epithelial cells were further transplanted into the corpus striatum of healthy adult rats and the grafted cells could integrate with the host and migrate 1-2 mm along the nerve fibers in corpus callosum. Our experimental findings indicate that human amniotic epithelial cells may be a new kind of seed cells for use in neurograft.

  1. Beta-3 adrenergic receptor is expressed in acetylcholine-containing nerve fibers of the human urinary bladder: An immunohistochemical study.

    Science.gov (United States)

    Coelho, Ana; Antunes-Lopes, Tiago; Gillespie, James; Cruz, Francisco

    2017-11-01

    To identify in the human bladder the structures which express the Beta-3 adrenoceptor (β3AR). Human bladders from cadaveric organ donors (equally balanced in sex and age) were collected. Bladders were immediately fixed in paraformaldehyde and further processed for cryostat sectioning. Single and double immunohistochemistry was performed using antibodies against β3AR C-terminal, β3AR N-terminal, a pan-neuronal marker (β3-Tubulin) and markers of cholinergic (Vesicular Acetylcholine Transporter), adrenergic (Tyrosine Hidroxylase), and peptidergic (Calcitonin Gene-Related Peptide) nerve fibers. Nerve fibers expressing immunoreactivity for β3AR were abundantly found in the mucosa and muscular layers of the human bladder. No β3AR-IR was detected on urothelial or smooth muscle cells. The presence of β3AR-IR in nerve fibers was confirmed by co-expression with β3-Tubulin. Nerve fibers expressing β3AR-IR were cholinergic, VAChT(+) , and abundantly observed in the suburothelium. The cholinergic fibers were in close proximity and intermingled with adrenergic TH(+) and peptidergic CGRP(+) fibers. We demonstrated that β3AR is abundantly located in acetylcholine-containing nerve fibers. These findings have important consequences to understand the mechanism of action of β3AR agonists currently used for the treatment of OAB. © 2017 Wiley Periodicals, Inc.

  2. Growth Factor and Laminin Effect with Muscular Fiber Sheath on Repairing of the Sciatica Nerve

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    S Torabi

    2014-01-01

    Background & aim: Peripheral nerve injuries which can lead to a physical disability. If the defect is very low, direct suture without tension on both ends of the cut nerve regeneration is considered as a standard procedure. Otherwise, to reconstruct the axons, the gap must be filled by graft material in order to the guidance. Due to the similarity of the matrix tubular skeletal muscle and nerve muscles graft was used to repair in this study. Methods: In the present experimental study, 42 female Wistar rats were divided into three groups and underwent surgery. In the first group a narrow strip of muscle was prepared by freezing – thawing, and later sutured between the distal and proximal sciatic nerve. In the second group, the gap caused by muscle graft was regenerated and the nerve growth factor and laminin was injected into the graft. In the control group, the two ends of the cut nerve were hidden beneath the adjacent muscles. Next, a group of rats with sciatic functional index was investigated for the behavioral. On the other group were examined for histological studies after two months. Results: Sciatic functional index and Mean counts of myelinated fibers in two graft groups compared with the control group was significant p<0.05. Statistical analysis was performed using ANOVA test. Conclusion: co-axially aligned muscle grafts were an appropriate alternative substitute for repairing. It seems that the nerve growth factor and laminin have a positive role in axonal regeneration and functional recovery acceleration. Key words: Sciatic Functional Index, muscle graft, NGF, Laminin

  3. Water translocation from the axial cylinder to myelin sheath structures of the nerve fiber.

    Science.gov (United States)

    Sotnikov, O S; Kokurina, T N; Kuznetsova, I N; Vasyagina, N Yu

    2011-10-01

    We studied isolated myelinated nerve fibers from frog sciatic nerve surviving in Ringer solution or in water-free liquid perfluorodecalin immiscible with water or mineral oil. Swelling of incisures and perikaryon, loosening of myelin in the node, and formation of the axial cylinder varicosities were found in the fibers surviving in Ringer solution after 5-7 h. The same process, swelling of Schmidt-Lantermann myelin incisures, Schwann cell perikaryon, and loosening of myelin lamellae in the Ranvier nodes was found in water-free perfluorodecalin medium. However, swelling of the perikaryon and incisures spread along the axial cylinder and the reaction of the fiber developed in perfluorodecalin much later and unfolded slower than in the control. These changes developed much sooner and progressed much more rapidly than in perfluorodecalin in fibers surviving in mineral oil. Swelling of the myelin sheath structures in water-free medium indicated an uncommon new form of the neuron-glia relationships: water translocation from the axial cylinder to Schwann cell under unfavorable conditions.

  4. Differentiation of Nerve Fibers Storing CGRP and CGRP Receptors in the Peripheral Trigeminovascular System

    DEFF Research Database (Denmark)

    Eftekhari, Sajedeh; Warfvinge, Karin; Blixt, Frank W

    2013-01-01

    Primary headaches such as migraine are postulated to involve the activation of sensory trigeminal pain neurons that innervate intracranial blood vessels and the dura mater. It is suggested that local activation of these sensory nerves may involve dural mast cells as one factor in local inflammation...... and in human dural vessels. The relative distributions of CGRP, CLR, and RAMP1 were evaluated with respect to each other and in relationship to mast cells, myelin, substance P, neuronal nitric oxide synthase, pituitary adenylate cyclase-activating polypeptide, and vasoactive intestinal peptide. CGRP expression...... was found in thin unmyelinated fibers, whereas CLR and RAMP1 were expressed in thicker myelinated fibers coexpressed with an A-fiber marker. CLR and RAMP1 immunoreactivity colocalized with mast cell tryptase in rodent; however, expression of both receptor components was not observed in human mast cells...

  5. Somatostatin-immunoreactive nerve cell bodies and fibers in the medulla oblongata et spinalis.

    Science.gov (United States)

    Forssmann, W G; Burnweit, C; Shehab, T; Triepel, J

    1979-10-01

    Complete serial sectioning of the medulla oblongata in monkey, cat, guinea pig, and japanese dancing mouse and incubation for somatostatin-immunoreaction was carried out. Numerous regions of the medulla oblongata such as the nucleus reticularis gigantocellularis, nucleus cuneatus et gracillis, nucleus raphe magnus, nucleus tractus solitarius, nucleus vestibularis, and parts of the oliva contain dense networks of somatostatin-immunoreactive nerve fibers. Cell bodies were seen in the nucleus reticularis medullae oblongatae. In the spinal cord the sections from each segment were analyzed, showing the highest concentrations of somatostatinergic fibers in the substantia gelantinosa of the columna dorsalis. Cell bodies were seen in the zona intermedia centralis, especially in the upper cervical segments. Many positive fibers were also seen in the entire zona intermedia and the columna ventralis. Especially prominent was the immunoreactivity in the zona intermediolateralis of the thoracic segments and the columna ventralis of the lower lumbar and sacral segments.

  6. Evaluation of peripheral compression and auditory nerve fiber intensity coding using auditory steady-state responses

    DEFF Research Database (Denmark)

    Encina Llamas, Gerard; M. Harte, James; Epp, Bastian

    2015-01-01

    cause auditory nerve fiber (ANF) deafferentation in predominantly low-spontaneous rate (SR) fibers. In the present study, auditory steadystate response (ASSR) level growth functions were measured to evaluate the applicability of ASSR to assess compression and the ability to code intensity fluctuations...... at high stimulus levels. Level growth functions were measured in normal-hearing adults at stimulus levels ranging from 20 to 90 dB SPL. To evaluate compression, ASSR were measured for multiple carrier frequencies simultaneously. To evaluate intensity coding at high intensities, ASSR were measured using....... The results indicate that the slope of the ASSR level growth function can be used to estimate peripheral compression simultaneously at four frequencies below 60 dB SPL, while the slope above 60 dB SPL may provide information about the integrity of intensity coding of low-SR fibers....

  7. Some posterior branches of extralaryngeal recurrent laryngeal nerves have motor fibers.

    Science.gov (United States)

    Cho, Ilyoung; Jo, Min-Gyu; Choi, Sung-Won; Jang, Jeon Yeob; Wang, Soo-Geun; Cha, Wonjae

    2017-11-01

    Anatomical variations of the recurrent laryngeal nerve (RLN), such as extralaryngeal branching, are a well-known risk factor for RLN injury during thyroid surgery. This study aimed to analyze the surgical anatomy and to investigate the existence of posterior branch motor fibers of extralaryngeal RLNs. Prospective consecutive observational study. This was a prospective cohort study of 366 patients between January 2014 and February 2016. Operative data included the type of operation, incidence of nerve bifurcation, the distances among anatomical landmarks. The motor fibers were evaluated using neurostimulation with laryngeal palpation. A total of 667 RLNs at risk were analyzed in this study, and of these 103 (14.5%) nerves were bifurcated or trifurcated before the laryngeal entry point (LEP). More extralaryngeal branched RLNs were observed on the right side than on the left (17.5% vs. 13.3%, P = .294). The mean distance of the LEP point of division was longer on the left side (16.2 ± 6.7 mm) than on the right (14.7 ± 5.9 mm, P = .132). All branched RLNs had a palpable laryngeal twitch when stimulating anterior branches. When stimulating posterior branches, 28.2%(29/103) of branched RLNs showed palpable laryngeal twitch. Overall incidence of posterior motor branch in total RLNs was 4.3% (29/667). The motor fibers of the RLN are all located in the anterior branch, whereas some posterior branches have motor function. Identification of all of the branches of the RLN may be mandatory to decrease the risk of postoperative nerve injury. 4. Laryngoscope, 127:2678-2685, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  8. Reflectance Spectrum and Birefringence of the Retinal Nerve Fiber Layer With Hypertensive Damage of Axonal Cytoskeleton

    Science.gov (United States)

    Huang, Xiang-Run; Knighton, Robert W.; Spector, Ye Z.; Qiao, Jianzhong; Kong, Wei; Zhao, Qi

    2017-01-01

    Purpose Glaucoma damages the retinal nerve fiber layer (RNFL). This study used precise multimodal image registration to investigate the changes of the RNFL reflectance spectrum and birefringence in nerve fiber bundles with different degrees of axonal damage. Methods The reflectance spectrum of individual nerve fiber bundles in normal rats and rats with experimental glaucoma was measured from 400 to 830 nm and their birefringence was measured at 500 nm. Optical measurements of the same bundles were made at different distances from the optic nerve head (ONH). After the optical measurements, the axonal cytoskeleton of the RNFL was evaluated by confocal microscopy to assess the severity of cytoskeletal change. Results For normal bundles, the shape of the RNFL reflectance spectrum and the value of RNFL birefringence did not change along bundles. In treated retinas, damage to the cytoskeleton varied within and across retinas. The damage in retinal sectors was subjectively graded from normal-looking to severe. Change of spectral shape occurred near the ONH in all sectors studied. This change became more prominent and occurred farther from the ONH with increased damage severity. In contrast, RNFL birefringence did not show change in normal-looking sectors, but decreased in sectors with mild and moderate damage. The birefringence of severely damaged sectors was either within or below the normal range. Conclusions Varying degrees of cytoskeletal damage affect the RNFL reflectance spectrum and birefringence differently, supporting differences in the ultrastructural basis for the two optical properties. Both properties, however, may provide a means to detect disease and to estimate ultrastructural damage of the RNFL in glaucoma. PMID:28395028

  9. Periosteum Metabolism and Nerve Fiber Positioning Depend on Interactions between Osteoblasts and Peripheral Innervation in Rat Mandible

    Science.gov (United States)

    Mauprivez, Cédric; Bataille, Caroline; Baroukh, Brigitte; Llorens, Annie; Lesieur, Julie; Marie, Pierre J.; Saffar, Jean-Louis; Biosse Duplan, Martin; Cherruau, Marc

    2015-01-01

    The sympathetic nervous system controls bone remodeling by regulating bone formation and resorption. How nerves and bone cells influence each other remains elusive. Here we modulated the content or activity of the neuropeptide Vasoactive Intestinal Peptide to investigate nerve-bone cell interplays in the mandible periosteum by assessing factors involved in nerve and bone behaviors. Young adult rats were chemically sympathectomized or treated with Vasoactive Intestinal Peptide or Vasoactive Intestinal Peptide10-28, a receptor antagonist. Sympathectomy depleted the osteogenic layer of the periosteum in neurotrophic proNerve Growth Factor and neurorepulsive semaphorin3a; sensory Calcitonin-Gene Related Peptide-positive fibers invaded this layer physiologically devoid of sensory fibers. In the periosteum non-osteogenic layer, sympathectomy activated mast cells to release mature Nerve Growth Factor while Calcitonin-Gene Related Peptide-positive fibers increased. Vasoactive Intestinal Peptide treatment reversed sympathectomy effects. Treating intact animals with Vasoactive Intestinal Peptide increased proNerve Growth Factor expression and stabilized mast cells. Vasoactive Intestinal Peptide10-28 treatment mimicked sympathectomy effects. Our data suggest that sympathetic Vasoactive Intestinal Peptide modulate the interactions between nervous fibers and bone cells by tuning expressions by osteogenic cells of factors responsible for mandible periosteum maintenance while osteogenic cells keep nervous fibers at a distance from the bone surface. PMID:26509533

  10. Survey of Nerve Fiber Layer Thickness in Anisometropic and Strabismic Amblyopia.

    Science.gov (United States)

    Soltani Moghaddam, Reza; Medghalchi, Abdolreza; Alizadeh, Yousef

    2017-01-01

    . To investigate the effect of anisometropic and strabismic amblyopia on the nerve fiber layer thickness. This cross-sectional study was done on 54 amblyopic subjects, equally in both strabismic and anisometropic groups. The thickness otonerve fiber layer measured in superior, inferior, nasal, temporal quadrants and as a whole in both eyes of both groups. The means of thickness were compared in amblyopic and sound eyes. In strabismus group, the average nerve fiber layer thickness of the sound eye , in superior, inferior, nasal and temporal quadrants and as a whole were 113.23±14, 117.37±25, 68.96±6, 69.55±14 and 93.40±8 microns respectively. In amblyopic eyes of the same group, these measurements were 103.11±18, 67.74±11, and 69.59±16 and 89.59±12 microns in superior, inferior, nasal, temporal quadrants and as whole respectively. In anisometropic groups, the sound eye measurements were as 130.96±22, 129.07±29, 80.62±12, and 83.88±20 and 107.7±13 microns in superior, inferior, nasal and temporal quadrants and as a whole orderly. In amblyopic eyes of this group the mean thicknesses were 115.63±29, 133.15±25, 78.8±15, 80.2±16 and 109.17±21 microns in superior, inferior, nasal, temporal quadrants and as a whole respectively. Statistically, there were no significant differences between amblyopic and sound eyes (P>0.5). Our study did not support any significant change in a nerve fiber layer thickness of amblyopic patients; however, decreased thickness in superior and nasal quadrants of strabismic amblyopia and except inferior quadrant and as a whole. These measurements may be a clue for management and prognosis of amblyopia in old age.

  11. Survey of Nerve Fiber Layer Thickness in Anisometropic and Strabismic Amblyopia

    Directory of Open Access Journals (Sweden)

    Reza Soltani Moghaddam

    2017-02-01

    Full Text Available . To investigate the effect of anisometropic and strabismic amblyopia on the nerve fiber layer thickness. This cross-sectional study was done on 54 amblyopic subjects, equally in both strabismic and anisometropic groups. The thickness otonerve fiber layer measured in superior, inferior, nasal, temporal quadrants and as a whole in both eyes of both groups. The means of thickness were compared in amblyopic and sound eyes. In strabismus group, the average nerve fiber layer thickness of the sound eye , in superior, inferior, nasal and temporal quadrants and as a whole were 113.23±14, 117.37±25, 68.96±6, 69.55±14 and 93.40±8 microns respectively. In amblyopic eyes of the same group, these measurements were 103.11±18, 67.74±11, and 69.59±16 and 89.59±12 microns in superior, inferior, nasal, temporal quadrants and as whole respectively. In anisometropic groups, the sound eye measurements were as 130.96±22, 129.07±29, 80.62±12, and 83.88±20 and 107.7±13 microns in superior, inferior, nasal and temporal quadrants and as a whole orderly. In amblyopic eyes of this group the mean thicknesses were 115.63±29, 133.15±25, 78.8±15, 80.2±16 and 109.17±21 microns in superior, inferior, nasal, temporal quadrants and as a whole respectively. Statistically, there were no significant differences between amblyopic and sound eyes (P>0.5. Our study did not support any significant change in a nerve fiber layer thickness of amblyopic patients; however, decreased thickness in superior and nasal quadrants of strabismic amblyopia and except inferior quadrant and as a whole. These measurements may be a clue for management and prognosis of amblyopia in old age.

  12. Pulp nerve fibers distribution of human carious teeth: An immunohistochemical study

    Directory of Open Access Journals (Sweden)

    Tetiana Haniastuti

    2010-12-01

    Full Text Available Background: Human dental pulp is richly innervated by trigeminal afferent axons that subserve nociceptive function. Accordingly, they respond to stimuli that induce injury to the pulp tissue. An injury to the nerve terminals and other tissue components in the pulp stimulate metabolic activation of the neurons in the trigeminal ganglion which result in morphological changes in the peripheral nerve terminals. Purpose: The aim of the study was to observe caries-related changes in the distribution of human pulpal nerve. Methods: Under informed consents, 15 third molars with caries at various stages of decay and 5 intact third molars were extracted because of orthodontic or therapeutic reasons. All samples were observed by micro-computed tomography to confirm the lesion condition 3-dimensionally, before decalcifying with 10% EDTA solution (pH 7.4. The specimens were then processed for immunohistochemistry using anti-protein gene products (PGP 9.5, a specific marker for the nerve fiber. Results: In normal intact teeth, PGP 9.5 immunoreactive nerve fibers were seen concentrated beneath the odontoblast cell layer. Nerve fibers exhibited an increased density along the pulp-dentin border corresponding to the carious lesions. Conclusion: Neural density increases throughout the pulp chamber with the progression of caries. The activity and pathogenicity of the lesion as well as caries depth, might influence the degree of neural sprouting.Latar belakang: Pulpa gigi manusia diinervasi oleh serabut saraf trigeminal yang berespon terhadap stimuli penyebab perlukaan dengan menimbulkan rasa sakit. Perlukaan pada akhiran saraf dan komponen lain dari pulpa akan menstimulasi aktivasi metabolik dari neuron pada ganglion trigeminal sehingga mengakibatkan perubahan morfologi pada akhiran saraf perifer. Tujuan: Penelitian ini bertujuan untuk mengamati perubahan distribusi saraf pada pulpa gigi manusia yang disebabkan oleh proses karies. Metode: Penelitian ini menggunakan

  13. Topiramate improves neurovascular function, epidermal nerve fiber morphology, and metabolism in patients with type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Boyd A

    2010-12-01

    Full Text Available Amanda L Boyd, Patricia M Barlow, Gary L Pittenger, Kathryn F Simmons, Aaron I VinikDepartment of Internal Medicine, Eastern Virginia Medical School, Norfolk, VA, USAPurpose: To assess the effects of topiramate on C-fiber function, nerve fiber morphology, and metabolism (including insulin sensitivity, obesity, and dyslipidemia in type 2 diabetes.Patients and methods: We conducted an 18-week, open-label trial treating patients with topiramate. Twenty subjects with type 2 diabetes and neuropathy (61.5 ± 1.29 years; 15 male, 5 female were enrolled and completed the trial. Neuropathy was evaluated by total neuropathy scores, nerve conduction studies, quantitative sensory tests, laser Doppler skin blood flow, and intraepidermal nerve fibers in skin biopsies.Results: Topiramate treatment improved symptoms compatible with C-fiber dysfunction. Weight, blood pressure, and hemoglobin A1c also improved. Laser Doppler skin blood flow improved significantly after 12 weeks of treatment, but returned to baseline at 18 weeks. After 18 weeks of treatment there was a significant increase in intraepidermal nerve fiber length at the forearm, thigh, and proximal leg. Intraepidermal nerve fiber density was significantly increased by topiramate in the proximal leg.Conclusion: This study is the first to demonstrate that it is possible to induce skin intraepidermal nerve fiber regeneration accompanied by enhancement of neurovascular function, translating into improved symptoms as well as sensory nerve function. The simultaneous improvement of selective metabolic indices may play a role in this effect, but this remains to be determined.Keywords: diabetic neuropathy, skin blood flow, skin biopsy, diabetes

  14. Extracellular Recording of Light Responses from Optic Nerve Fibers and the Caudal Photoreceptor in the Crayfish.

    Science.gov (United States)

    Nesbit, Steven C; Van Hoof, Alexander G; Le, Chi C; Dearworth, James R

    2015-01-01

    Few laboratory exercises have been developed using the crayfish as a model for teaching how neural processing is done by sensory organs that detect light stimuli. This article describes the dissection procedures and methods for conducting extracellular recording from light responses of both the optic nerve fibers found in the animal's eyestalk and from the caudal photoreceptor located in the ventral nerve cord. Instruction for ADInstruments' data acquisition system is also featured for the data collection and analysis of responses. The comparison provides students a unique view on how spike activities measured from neurons code image-forming and non-image-forming processes. Results from the exercise show longer latency and lower frequency of firing by the caudal photoreceptor compared to optic nerve fibers to demonstrate evidence of different functions. After students learn the dissection, recording procedure, and the functional anatomy, they can develop their own experiments to learn more about the photoreceptive mechanisms and the sensory integration of modalities by these light-responsive interneurons.

  15. Wavelength-dependent change of retinal nerve fiber layer reflectance in glaucomatous retinas.

    Science.gov (United States)

    Huang, Xiang-Run; Zhou, Ye; Knighton, Robert W; Kong, Wei; Feuer, William J

    2012-08-24

    Retinal nerve fiber layer (RNFL) reflectance is often used in optical methods for RNFL assessment in clinical diagnosis of glaucoma, yet little is known about the reflectance property of the RNFL under the development of glaucoma. This study measured the changes in RNFL reflectance spectra that occurred in retinal nerve fiber bundles with different degrees of glaucomatous damage. A rat model of glaucoma with laser photocoagulation of trabecular meshwork was used. Reflectance of the RNFL in an isolated retina was measured at wavelengths of 400-830 nm. Cytostructural distribution of the bundles measured optically was evaluated by confocal imaging of immunohistochemistry staining of cytoskeletal components, F-actin, microtubules, and neurofilaments. RNFL reflectance spectra were studied in bundles with normal-looking appearance, early F-actin distortion, and apparent damage of all cytoskeletal components. Changes of RNFL reflectance spectra were studied at different radii (0.22, 0.33, and 0.44 mm) from the optic nerve head (ONH). Bundles in 30 control retinas and 41 glaucomatous retinas were examined. In normal retinas, reflectance spectra were similar along the same bundles. In glaucomatous retinas, reflectance spectra changed along bundles with the spectra becoming flatter as bundle areas approached the ONH. Elevation of intraocular pressure (IOP) causes nonuniform changes in RNFL reflectance across wavelengths. Changes of reflectance spectra occur early in bundles near the ONH and prior to apparent cytoskeletal distortion. Using the ratio of RNFL reflectance measured at different wavelengths can provide early and sensitive detection of glaucomatous damage.

  16. Genetics Home Reference: small fiber neuropathy

    Science.gov (United States)

    ... Waxman SG. Small-fibre neuropathies--advances in diagnosis, pathophysiology and management. Nat Rev Neurol. 2012 May 29; ... newborn screening? New Pages MDA5 deficiency type 2 diabetes mitochondrial complex I deficiency All New & Updated Pages ...

  17. Establishment of nerve growth factor gradients on aligned chitosan-polylactide /alginate fibers for neural tissue engineering applications.

    Science.gov (United States)

    Wu, Hua; Liu, Jiaoyan; Fang, Qing; Xiao, Bo; Wan, Ying

    2017-10-05

    Nerve conduits containing aligned fibrous fillers with gradiently distributed signal molecules are essential for long-gap nerve repair. This study was to develop an approach for establishing nerve growth factor (NGF) gradients onto the aligned chitosan-polylactide (CH-PLA) fibers. CH-PLA containing 37wt% of PLA was spun into fibers using a wet-spinning technique. CH-PLA fibers showed much higher wet-state tensile strength, enhanced degradation tolerance and significantly lower swelling degree in comparison to chitosan fibers. The CH-PLA fibers with diameters from 40 to 60μm were selected and segmentally coated in bundles using NGF-contained alginate solutions to establish NGF gradients lengthwise along fibers. The diameter of resulting NGF-loaded CH-PLA/alginate fibers was well controlled within a range between 60 and 120μm. Calcium ion crosslinked alginate coating layers on fibers showed abilities to administer the sustainable NGF release in a gradient distribution manner for at least 5 weeks. NGF-induced neurite outgrowth of PC12 cells confirmed that bioactivity of NGF released from fibers was well retained. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. The reduction of intraepidermal P2X3 nerve fiber density correlates with behavioral hyperalgesia in a rat model of nerve injury-induced pain

    NARCIS (Netherlands)

    Bechakra, Malik; Schüttenhelm, Barthold N; Pederzani, Tiziana; van Doorn, Pieter A; de Zeeuw, Chris I; Jongen, Joost L M

    2017-01-01

    Skin biopsies from patients with neuropathic pain often show changes in epidermal innervation, although it remains to be elucidated to what extent such changes can be linked to a particular subgroup of nerve fibers and how these changes are correlated with pain intensity. Here, we investigated to

  19. An Injectable Hybrid Hydrogel with Oriented Short Fibers Induces Unidirectional Growth of Functional Nerve Cells.

    Science.gov (United States)

    Omidinia-Anarkoli, Abdolrahman; Boesveld, Sarah; Tuvshindorj, Urandelger; Rose, Jonas C; Haraszti, Tamás; De Laporte, Laura

    2017-09-01

    To regenerate soft aligned tissues in living organisms, low invasive biomaterials are required to create 3D microenvironments with a structural complexity to mimic the tissue's native architecture. Here, a tunable injectable hydrogel is reported, which allows precise engineering of the construct's anisotropy in situ. This material is defined as an Anisogel, representing a new type of tissue regenerative therapy. The Anisogel comprises a soft hydrogel, surrounding magneto-responsive, cell adhesive, short fibers, which orient in situ in the direction of a low external magnetic field, before complete gelation of the matrix. The magnetic field can be removed after gelation of the biocompatible gel precursor, which fixes the aligned fibers and preserves the anisotropic structure of the Anisogel. Fibroblasts and nerve cells grow and extend unidirectionally within the Anisogels, in comparison to hydrogels without fibers or with randomly oriented fibers. The neurons inside the Anisogel show spontaneous electrical activity with calcium signals propagating along the anisotropy axis of the material. The reported system is simple and elegant and the short magneto-responsive fibers can be produced with an effective high-throughput method, ideal for a minimal invasive route for aligned tissue therapy. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Identification and segmentation of myelinated nerve fibers in a cross-sectional optical microscopic image using a deep learning model.

    Science.gov (United States)

    Naito, Tatsuhiko; Nagashima, Yu; Taira, Kenichiro; Uchio, Naohiro; Tsuji, Shoji; Shimizu, Jun

    2017-11-01

    The morphometric analysis of myelinated nerve fibers of peripheral nerves in cross-sectional optical microscopic images is valuable. Several automated methods for nerve fiber identification and segmentation have been reported. This paper presents a new method that uses a deep learning model of a convolutional neural network (CNN). We tested it for human sural nerve biopsy images. The method comprises four steps: normalization, clustering segmentation, myelinated nerve fiber identification, and clump splitting. A normalized sample image was separated into individual objects with clustering segmentation. Each object was applied to a CNN deep learning model that labeled myelinated nerve fibers as positive and other structures as negative. Only positives proceeded to the next step. For pretraining the model, 70,000 positive and negative data each from 39 samples were used. The accuracy of the proposed algorithm was evaluated using 10 samples that were not part of the training set. A P-value of deep learning model. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. [New approach to corneal nerve fibers morphometry in diabetes mellitus on the basis of confocal biomicroscopy].

    Science.gov (United States)

    Avetisov, S E; Novikov, I A; Makhotin, S S; Surnina, Z V

    2015-01-01

    to develop a new approach to morphometric analysis of corneal nerve fibers (CNF) and to evaluate their age-related changes in type 1 and type 2 diabetes mellitus patients. The study enrolled 150 participants (300 eyes) aged from 13 to 83 years, of them 37 type 1 diabetes patients (74 eyes), 51 type 2 diabetes patients (102 eyes), and 62 healthy volunteers (124 eyes). All participants were examined with HRT III Rostock Corneal Module (Heidelberg Engineering GmbH). Digital images thus obtained were analyzed with specially developed original software that automatically computes coefficients of CNF orientation symmetry and anisotropy. A strong inverse correlation has been found between the coefficient of CNF orientation anisotropy and glycated hemoglobin levels (r = -0.83, p diabetes respectively) as well as the duration of the disease (r = -0,7, p diabetes respectively). On the contrary, the coefficient of CNF orientation symmetry has been shown to be directly correlated with both glycated hemoglobin levels (r = 0.64, p diabetes respectively) and the duration of the disease (r = 0.62, p diabetes respectively). Interocular asymmetry in both coefficients was found in diabetic patients but not in the controls. On the basis of the proposed coefficients, age-related changes in corneal nerve fibers orientation have been determined. Normally, the degree of CNF tortuosity increases with age. The rate of this increase is the highest before the age of 35-40. As shown, type 1 diabetes is associated with low coefficients of CNF orientation anisotropy and high coefficients of CNF orientation symmetry as compared to type 2 diabetes in the same age group. As suggested by the results, the two proposed coefficients that describe the state of corneal nerve fibers can possibly be used for diagnosis and monitoring of diabetic peripheral neuropathy (DPN). However, to produce enough evidence, further studies should be conducted.

  2. Dopamine release from serotonergic nerve fibers is reduced in L-DOPA-induced dyskinesia

    Science.gov (United States)

    Nevalainen, Nina; af Bjerkén, Sara; Lundblad, Martin; Gerhardt, Greg A.; Strömberg, Ingrid

    2011-01-01

    L-DOPA (3,4-dihydroxyphenyl-L-alanine) is the most commonly used treatment for symptomatic control in patients with Parkinson’s disease. Unfortunately, most patients develop severe side effects, such as dyskinesia, upon chronic L-DOPA treatment. The patophysiology of dyskinesia is unclear, however, involvement of serotonergic nerve fibers in converting L-DOPA to dopamine has been suggested. Therefore, potassium-evoked dopamine release was studied after local application of L-DOPA in the striata of normal, dopamine- and dopamine/serotonin-lesioned L-DOPA naïve, and dopamine-denervated chronically L-DOPA-treated dyskinetic rats using in vivo chronoamperometry. The results revealed that local L-DOPA administration into normal and intact hemisphere of dopamine-lesioned L-DOPA naïve animals significantly increased the potassium-evoked dopamine release. L-DOPA application also increased the dopamine peak amplitude in the dopamine-depleted L-DOPA naïve striatum, although these dopamine levels were several-folds lower than in the normal striatum, while no increased dopamine release was found in the dopamine/serotonin-denervated striatum. In dyskinetic animals, local L-DOPA application did not affect the dopamine release, resulting in significantly attenuated dopamine levels compared to those measured in L-DOPA naïve dopamine-denervated striatum. To conclude, L-DOPA is most likely converted to dopamine in serotonergic nerve fibers in the dopamine-depleted striatum, but the dopamine release is several-fold lower than in normal striatum. Furthermore, L-DOPA loading does not increase the dopamine release in dyskinetic animals as found in L-DOPA naïve animals, despite similar density of serotonergic innervation. Thus, the dopamine overflow produced from the serotonergic nerve fibers appears not to be the major cause of dyskinetic behavior. PMID:21534956

  3. Clinical analysis of retinal nerve fiber layer thickness and macular fovea in hyperopia children with anisometropia amblyopia

    Directory of Open Access Journals (Sweden)

    Fei-Fei Li

    2017-10-01

    Full Text Available AIM:To analyze the clinical significance of axial length, diopter and retinal nerve fiber layer thickness in hyperopia children with anisometropia amblyopia. METHODS: From January 2015 to January 2017 in our hospital for treatment, 103 cases, all unilateral, were diagnosed as hyperopia anisometropia amblyopia. The eyes with amblyopia were as experimental group(103 eyes, another normal eye as control group(103 eyes. We took the detection with axial length, refraction, foveal thickness, corrected visual acuity, diopter and the average thickness of retinal nerve fiber layer. RESULTS: Differences in axial length and diopter and corrected visual acuity were statistically significant between the two groups(PP>0.05. There was statistical significance difference on the foveal thickness(PP>0.05. The positive correlation between diopter with nerve fiber layer thickness of foveal and around the optic disc were no statistically significant difference(P>0.05. CONCLUSION: Retinal thickness of the fovea in the eye with hyperopic anisometropia amblyopia were thicker than those in normal eyes; the nerve fiber layer of around the optic disc was not significantly different between the amblyopic eyes and contralateral eyes. The refraction and axial length had no significant correlation with optic nerve fiber layer and macular foveal thickness.

  4. Modification of sodium channel inactivation in single myelinated nerve fibers by methionine-reactive chemicals.

    Science.gov (United States)

    Wang, G K

    1984-01-01

    Several methionine-reactive reagents, including N-bromoacetamide, N-bromosuccinimide, chloramine-T, and N-chlorosuccinimide, irreversibly slowed and prevented Na channel inactivation in single myelinated nerve fibers, whereas sulfhydryl- or tyrosine-modifying reagents had little effect. The activation process was not modified by the reagents that altered inactivation and could be modulated normally by Ca++ ions and Centruroides scorpion toxin II alpha. These results suggest that externally applied N-bromoacetamide and its related compounds specifically affect Na channel inactivation by modifying methionine residues of the channel. PMID:6331542

  5. Human primordial germ cells migrate along nerve fibers and Schwann cells from the dorsal hind gut mesentery to the gonadal ridge

    DEFF Research Database (Denmark)

    Møllgård, Kjeld; Jespersen, Åse; Lutterodt, Melissa Catherine

    2010-01-01

    The aim of this study was to investigate the spatiotemporal development of autonomic nerve fibers and primordial germ cells (PGCs) along their migratory route from the dorsal mesentery to the gonadal ridges in human embryos using immunohistochemical markers and electron microscopy. Autonomic nerve...... and their intimate contact with PGCs. PGCs expressed GAGE, MAGE-A4, OCT4 and c-Kit. Serial paraffin sections showed that most PGCs were located inside bundles of autonomic nerve fibers with the majority adjacent to the most peripheral fibers (close to Schwann cells). We also show that both nerve fibers and PGCs...... arrive at the gonadal ridge between 29 and 33 days pc. In conclusion, our data suggest that PGCs in human embryos preferentially migrate along autonomic nerve fibers from the dorsal mesentery to the developing gonad where they are delivered via a fine nerve plexus....

  6. Small-fiber dysfunction in trigeminal neuralgia

    DEFF Research Database (Denmark)

    Cruccu, G.; Leandri, M.; Iannetti, G. D.

    2001-01-01

    on small-afferent (nociceptive) function. Methods: The brain potentials evoked by CO2-laser pulses directed to the perioral and supraorbital regions were studied in 67 patients with idiopathic or symptomatic trigeminal neuralgia and 30 normal subjects. Of the 67 patients, 49 were receiving carbamazepine...... was significantly longer than that of the age-matched controls. The nonpainful-side latency correlated significantly with the carbamazepine dose. Conclusions: LEP detect severe impairment of the nociceptive afferent system on the painful side of patients with idiopathic as well as symptomatic trigeminal neuralgia....... A dysfunction of small-myelinated afferents may play an important role in the pathophysiology of neuralgic pain. Carbamazepine markedly dampens these brain potentials. The authors propose that this effect may result from inhibition of nociceptive transmission in the cingulate gyrus....

  7. Utility of Heidelberg retinal tomography as a screening tool for analyzing retinal nerve fiber layer defects

    Directory of Open Access Journals (Sweden)

    Belyea DA

    2014-11-01

    Full Text Available David A Belyea, Rashed N Alhabshan, Sankaranarayana P Mahesh, Gregory S Gertner, Mirsad M Ibisevic,† Abdullah S Habib, Jacob A Dan Department of Ophthalmology, The George Washington University, Washington, DC, USA †Dr Mirsad Ibisevic passed away on January 4, 2013 Context: Although Heidelberg retinal tomography (HRT-generated topographic images have been studied extensively for the detection of retinal nerve fiber layer (RNFL defects, little is known about the role of HRT-generated surface reflectivity images in the detection of RNFL defects in either patients with glaucoma or glaucoma suspects. Aims: To evaluate the effectiveness of HRT version II (HRT II optic nerve reflectivity images in uncovering RNFL defects in an outpatient population evaluated for glaucoma.Study design/materials and methods: In 102 consecutive eyes from 60 patients evaluated for glaucoma in an academic-based practice, HRT II optic nerve images were prospectively imaged and compared with clinical optic nerve exam techniques to see if HRT II was able to detect RNFL defects overlooked in clinical practice. Results: Nine eyes (8.8% were found to have RNFL defects recognized by screening with HRT II. Of these nine eyes, eight (88.9% were recognized to demonstrate RNFL defects by conventional examination techniques. One additional eye had an RNFL defect seen on physical exam that was not detected by HRT. Conclusion: In academic practice, HRT II may be helpful in complementing conventional exam techniques in the recognition and documentation of acquired RNFL loss. Keywords: HRT, RNFL defect, optic nerve, glaucoma, glaucoma suspect

  8. [Progression of nerve fiber layer defects in retrobulbar optic neuritis by the macular ganglion cell complex].

    Science.gov (United States)

    Hong, D; Bosc, C; Chiambaretta, F

    2017-11-01

    Recent studies with SD OCT had shown early axonal damage to the macular ganglion cell complex (which consists of the three innermost layers of the retina: Inner Plexiform Layer [IPL], Ganglion Cell Layer [GCL], Retinal Nerve Fibre layer [RNFL]) in optic nerve pathology. Retrobulbar optic neuritis (RBON), occurring frequently in demyelinating diseases, leads to atrophy of the optic nerve fibers at the level of the ganglion cell axons, previously described in the literature. The goal of this study is to evaluate the progression of optic nerve fiber defects and macular ganglion cell complex defects with the SPECTRALIS OCT via a reproducible method by calculating a mean thickness in each quadrant after an episode of retrobulbar optic neuritis. This is a prospective monocentric observational study including 8 patients at the Clermont-Ferrand university medical center. All patients underwent ocular examination with macular and disc OCT analysis and a Goldmann visual field at the time of inclusion (onset or recurrence of RBON), at 3 months and at 6 months. Patients were 40-years-old on average at the time of inclusion. After 6 months of follow-up, there was progression of the atrophy of the macular ganglion cell complex in the affected eye on (11.5% or 11μm) predominantly inferonasally (13.9% or 16μm) and superonasally (12.9% or 14μm) while the other eye remained stable. The decrease in thickness occurred mainly in the most internal 3 layers of the retina. On average, the loss in thickness of the peripapillary RNFL was predominantly inferotemporal (24.9% or 39μm) and superotemporal (21.8% or 28μm). In 3 months of progression, the loss of optic nerve fibers is already seen on macular and disc OCT after an episode of RBON, especially in inferior quadrants in spite of the improvement in the Goldmann visual field and visual acuity. Segmentation by quadrant was used here to compare the progression of the defect by region compared to the fovea in a global and reproducible

  9. Polyploidy and small RNA regulation of cotton fiber development.

    Science.gov (United States)

    Guan, Xueying; Song, Qingxin; Chen, Z Jeffrey

    2014-08-01

    Cotton is not only the most important source of renewal textile fibers, but also an excellent model for studying cell fate determination and polyploidy effects on gene expression and evolution of domestication traits. The combination of A and D-progenitor genomes into allotetraploid cotton induces intergenomic interactions and epigenetic effects, leading to the unequal expression of homoeologous genes. Small RNAs regulate the expression of transcription and signaling factors related to cellular growth, development and adaptation. An example is miRNA-mediated preferential degradation of homoeologous mRNAs encoding MYB-domain transcription factors that are required for the initiation of leaf trichomes in Arabidopsis and of seed fibers in cotton. This example of coevolution between small RNAs and their homoeologous targets could shape morphological traits such as fibers during the selection and domestication of polyploid crops. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. Pharmacological switch in Aβ-fiber stimulation-induced spinal transmission in mice with partial sciatic nerve injury

    Directory of Open Access Journals (Sweden)

    Ma Lin

    2008-07-01

    Full Text Available Abstract Background We have previously demonstrated that different spinal transmissions are involved in the nociceptive behavior caused by electrical stimulation of Aβ-, Aδ- or C-fibers using a Neurometer® in naïve mice. In this study, we attempted to pharmacologically characterize the alteration in spinal transmission induced by partial sciatic nerve injury in terms of nociceptive behavior and phosphorylation of extracellular signal-regulated kinase (pERK in the spinal dorsal horn. Results Aβ-fiber responses (2000-Hz, which were selectively blocked by the AMPA/kainate antagonist CNQX in naïve mice, were hypersensitized but blocked by the NMDA receptor antagonists MK-801 and AP-5 in injured mice in an electrical stimulation-induced paw withdrawal (EPW test. Although Aδ-fiber responses (250-Hz were also hypersensitized by nerve injury, there was no change in the pharmacological characteristics of Aδ-fiber responses through NMDA receptors. On the contrary, C-fiber responses (5-Hz were hyposensitized by nerve injury. Moreover, Aδ- and C-, but not Aβ-fiber stimulations significantly increased the number of pERK-positive neurons in the superficial spinal dorsal horns of naïve mice, and corresponding antagonists used in the EPW test inhibited this increase. In mice with nerve injury, Aβ- as well as Aδ-fiber stimulations significantly increased the number of pERK-positive neurons in the superficial spinal dorsal horn, whereas C-fiber stimulation decreased this number. The nerve injury-specific pERK increase induced by Aβ-stimulation was inhibited by MK-801 and AP-5, but not by CNQX. However, Aβ- and Aδ-stimulations did not affect the number or size of pERK-positive neurons in the dorsal root ganglion, whereas C-fiber-stimulation selectively decreased the number of pERK-positive neurons. Conclusion These results suggest that Aβ-fiber perception is newly transmitted to spinal neurons, which originally receive only Aδ- and C-fiber

  11. Diagnosis of Late Stage, Early Onset, Small Fiber Polyneuropathy

    Science.gov (United States)

    2016-10-01

    98%), cognitive concerns (88%), and headache (72%). Internal consistency and test-retest reliability of the questionnaire were excellent. Specific...Klein MM. Evidence of small-fiber polyneuropathy in unexplained, juvenile-onset, widespread pain syndromes. Pediatrics 2013;131:e1091-e1100. 3

  12. THE MAJORITY OF MYELINATED AND UNMYELINATED SENSORY NERVE FIBERS THAT INNERVATE BONE EXPRESS THE TROPOMYOSIN RECEPTOR KINASE A

    OpenAIRE

    Castañeda-Corral, Gabriela; Jimenez-Andrade, Juan M.; Bloom, Aaron P.; Taylor, Reid N.; Mantyh, William G.; Kaczmarska, Magdalena J.; Ghilardi, Joseph R.; Mantyh, Patrick W.

    2011-01-01

    Although skeletal pain is a leading cause of chronic pain and disability, relatively little is known about the specific populations of nerve fibers that innervate the skeleton. Recent studies have reported that therapies blocking nerve growth factor (NGF) or its cognate receptor, tropomyosin receptor kinase A (TrkA) are efficacious in attenuating skeletal pain. A potential factor to consider when assessing the analgesic efficacy of targeting NGF-TrkA signaling in a pain state is the fraction ...

  13. Digestion modeling in the small intestine: impact of dietary fiber.

    Science.gov (United States)

    Taghipoor, M; Barles, G; Georgelin, C; Licois, J R; Lescoat, P

    2014-12-01

    In this work, the modeling of the digestion in the small intestine is developed by investigating specifically the effects of dietary fiber. As our previous model, this new version takes into account the three main phenomena of digestion: transit of the bolus, degradation of feedstuffs and absorption through the intestinal wall. However the two main physiochemical characteristics of dietary fiber, namely viscosity and water holding capacity, lead us to substantially modify our initial model by emphasizing the role of water and its intricated dynamics with dry matter in the bolus. Various numerical simulations given by this new model are qualitatively in agreement with the positive effect of insoluble dietary fiber on the velocity of bolus and on its degradation all along the small intestine. These simulations reproduce the negative effect of soluble dietary fiber on digestion as it has been experimentally observed. Although, this model is generic and contains a large number of parameters but, to the best of our knowledge, it is among the first qualitative dynamical models of fiber influence on intestinal digestion. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Distribution of transient receptor potential cation channel subfamily V member 1-expressing nerve fibers in mouse esophagus.

    Science.gov (United States)

    Matsumoto, Kenjiro; Hosoya, Takuji; Ishikawa, Eriko; Tashima, Kimihito; Amagase, Kikuko; Kato, Shinichi; Murayama, Toshihiko; Horie, Syunji

    2014-12-01

    Transient receptor potential cation channel subfamily V member 1 (TRPV1) plays a role in esophageal function. However, the distribution of TRPV1 nerve fibers in the esophagus is currently not well understood. In the present study, we investigated the distribution of TRPV1 and neurotransmitters released from TRPV1 nerve fibers in the mouse lower esophagus. Furthermore, we investigated changes in the presence of TRPV1 in the mouse model of esophagitis. Numerous TRPV1-immunoreactive nerve fibers were seen in both the submucosal layer and myenteric plexus of the lower esophagus and colocalized with calcitonin gene-related peptide (CGRP). TRPV1 colocalized with substance P in axons in the submucosal layer and myenteric plexus. TRPV1 colocalized with neuronal nitric oxide synthase in the myenteric plexus. We observed some colocalization of CGRP with the vesicular acetylcholine (ACh) transporter, packaging of ACh into synaptic vesicles after its synthesis in terminal cytoplasm, in the submucosal layer and myenteric plexus. In the esophagitis model, the number of the TRPV1 nerve fibers did not change, but their immunoreactive intensity increased compared with sham-operated mice. Inhibitory effect of exogenous capsaicin on electrically stimulated twitch contraction significantly increased in esophagitis model compared with the effect in sham-operated mice. Overall, these results suggest that TRPV1 nerve fibers projecting to both the submucosal and muscle layer of the esophagus are extrinsic spinal and vagal afferent neurons. Furthermore, TRPV1 nerve fibers contain CGRP, substance P, nitric oxide, and ACh. Therefore, acid influx-mediated TRPV1 activation may play a role in regulating esophageal relaxation.

  15. Progressive degeneration of the retinal nerve fiber layer in patients with multiple sclerosis.

    Science.gov (United States)

    Herrero, Raquel; Garcia-Martin, Elena; Almarcegui, Carmen; Ara, Jose R; Rodriguez-Mena, Diego; Martin, Jesus; Otin, Sofia; Satue, Maria; Pablo, Luis E; Fernandez, Francisco J

    2012-12-17

    To quantify changes in the retinal nerve fiber layer (RNFL) of patients with multiple sclerosis (MS) over 3 years and to evaluate whether treatment protects against RNFL degeneration. Ninety-four MS patients and 50 healthy subjects were followed-up over 3 years. All subjects underwent a complete ophthalmic examination, which included assessment of visual acuity (Snellen chart), color vision (Ishihara pseudoisochromatic plates), visual field examination, optical coherence tomography (OCT), and visual evoked potentials (VEPs). All patients were reevaluated at 12, 24, and 36 months to quantify changes in the RNFL. Changes were detected in RNFL thickness at the 36-month follow-up. Significant decreases (P < 0.05, t-test) were observed in the mean, superior, inferior, and temporal RNFL thicknesses, and macular volume provided by OCT, and in the P100 latency of VEP of the MS group, but only in the mean and inferior RNFL thicknesses of the healthy control group. Greater changes in the superior and inferior RNFL thicknesses during follow-up were detected in the MS group. Differences between treatments were not detected, but untreated patients had higher degeneration in the mean and superior RNFL thicknesses during the follow-up (P = 0.040 and P = 0.19, respectively). Progressive axonal loss can be detected in the optic nerve fiber layer of MS patients. Analysis of the RNFL by OCT can be useful for evaluating MS progression and efficacy of treatment as a neuroprotective factor against axonal degeneration.

  16. Evaluating Glaucomatous Retinal Nerve Fiber Damage by GDx VCC Polarimetry in Taiwan Chinese Population

    Science.gov (United States)

    Chen, Hsin-Yi; Huang, Mei-Ling; Huang, Wei-Cheng

    2010-01-01

    Purpose To study the capability of scanning laser polarimetry with variable corneal compensation (GDx VCC) to detect differences in retinal nerve fiber layer thickness between normal and glaucomatous eyes in a Taiwan Chinese population. Methods This study included 44 normal eyes and 107 glaucomatous eyes. The glaucomatous eyes were divided into three subgroups on the basis of its visual field defects (early, moderate, severe). Each subject underwent a GDx-VCC exam and visual field testing. The area under the receiver-operating characteristic curve (AROC) of each relevant parameter was used to differentiate normal from each glaucoma subgroup, respectively. The correlation between visual field index and each parameter was evaluated for the eyes in the glaucoma group. Results For normal vs. early glaucoma, the parameter with the best AROC was Nerve fiber indicator (NFI) (0.942). For normal vs. moderate glaucoma, the parameter showing the best AROC was NFI (0.985). For normal vs. severe glaucoma, the parameter that had the best AROC was NFI (1.000). For early vs. moderate glaucoma, the parameter with the best AROC was NFI (0.732). For moderate vs. severe, the parameter showing the best AROC was temporal-superior-nasal-inferior-temporal average (0.652). For early vs. severe, the parameter with the best AROC was NFI (0.852). Conclusions GDx-VCC-measured parameters may serve as a useful tool to distinguish normal from glaucomatous eyes; in particular, NFI turned out to be the best discriminating parameter.

  17. Evoked bioelectrical activity of efferent fibers of the sciatic nerve of white rats in experimental menopause

    Directory of Open Access Journals (Sweden)

    Rodinsky A.G.

    2016-03-01

    Full Text Available The aim of our work was analysis of the bioelectrical activity of efferent fibers of the sciatic nerve in experimental menopause condition. Experiments were performed on 25 female white rats, divided into experimental and control groups. Menopause was modeled by total ovariohysterectomy. In 120 days after modeling we had recorded evoked action potentials of fibers of isolated ventral root L5 induced by stimulation of sciatic nerve with rectangular pulses. Threshold, chronaxia, latency, amplitude and duration of the action potential (AP were analysed. Refractory phenomenon was investigated by applying paired stimuli at intervals of 2 to 20 ms. In the context of long-term hypoestrogenemy threshold of AP appearance was 55,32±7,69%, chronaxy – 115,09±2,67%, latent period – 112,62±1,74% as compared with the control animals (p<0.01. In conditions of paired stimuli applying the amplitude of response to the testing stimulus in animals with ovariohysterectomy at intervals 3 and 4 ms was 61,25±36,45% and 53,48±18,64% (p<0.05 respectively.

  18. Pattern of Retinal Nerve Fiber Layer Thickness Loss in Fetal Alcohol Syndrome: A Spectral-Domain Optical Coherence Tomography Analysis.

    Science.gov (United States)

    Menezes, Carlos; Ribeiro, Isabel; Coelho, Pedro; Mateus, Catarina; Teixeira, Carla

    2016-04-01

    Optic disc hypoplasia is a common feature in fetal alcohol syndrome. Thus, we aimed to evaluate the optic disc morphology changes and the peripapillary retinal nerve fiber layer thickness in these patients. We performed spectral-domain optical coherence tomography in a cohort of 11 patients (22 eyes) with fetal alcohol syndrome and in an age-matched control group. We evaluated optic nerve head parameters (optic disc area and diameter, rim area, cup/disc horizontal and vertical ratios) and peripapillary retinal nerve fiber layer thickness. Mean optic disc area, rim area and optic disc diameter were, respectively, in fetal alcohol syndrome patients and control subjects: 1.540 ± 0.268 and 1.748 ± 0.326 mm2; 1.205 ± 0.286 and 1.461 ± 0.314 mm2; 1.417 ± 0.124 and 1.501 ± 0.148 mm (p fetal alcohol syndrome patients (90.500 ± 9.344 µm) as compared to controls (111.000 ± 7.855 µm) (p fetal alcohol syndrome patients. Although mean peripapillary retinal nerve fiber layer thickness was decreased, the temporal quadrant was spared. In addition to a smaller optic disc area/ diameter and rim area, we found a heterogeneous peripapillary retinal nerve fiber layer thickness loss in fetal alcohol syndrome patients with sparing of the temporal quadrant. Spectral-domain optical coherence tomography may be useful to determine the presence of fetal alcohol syndrome status.

  19. Progressive changes in the retinal nerve fiber layer in patients with multiple sclerosis.

    Science.gov (United States)

    Garcia-Martin, Elena; Pueyo, Victoria; Martin, Jesus; Almarcegui, Carmen; Ara, Jose R; Dolz, Isabel; Honrubia, Francisco M; Fernandez, Francisco J

    2010-01-01

    To quantify changes in the retinal nerve fiber layer (RNFL) of patients with multiple sclerosis (MS) over a 1-year time period and to compare the ability of noninvasive diagnostic imaging devices and visual evoked potentials (VEP) to detect axonal loss in these patients. Eighty-one patients with MS underwent a complete ophthalmic examination that included assessment of visual acuity and color vision, refractive evaluation, visual field examination, optical coherence tomography (OCT), scanning laser polarimetry (GDx), and measurement of VEP. All the patients were re-evaluated after a period of 12 months in order to quantify any change in the RNFL. Only one randomly chosen eye from each patient was included in the study. Statistically significant differences between the 2 examinations were recorded for the overall mean and inferior RNFL thickness and the macular volume, as assessed by OCT, as well as for the temporal-superior-nasal-inferior-temporal average standard deviation provided by GDx. The greatest differences were obtained for the mean RNFL thickness (90.46 microm vs 85.96 microm). Changes in the optic nerve were detected by structural measurements but not by functional assessments. Axonal loss in the optic nerve of patients with MS is greater than that expected in healthy subjects, regardless of the presence of a previous optic neuritis.

  20. Evaluation of retinal nerve fiber layer thickness in a patient with bilateral optic disc drusen

    Directory of Open Access Journals (Sweden)

    Alime Gunes

    2015-06-01

    Full Text Available Optic disc drusen (ODD is the accumulations of calcified hyaline-like material within the substance of the optic nerve head. Optic disc drusen, especially if it is bilateral, may mimic the clinical presentation of papilledema. Usually retinal nerve fiber layer (RNFL thinning can be present in ODD. In this report we present uncommon RNFL changes in a patient with bilateral ODD. A 17-year-old male was referred by another center with a diagnosis of optic disc edema. The patient’s visual acuity, the slit-lamp examination and the intraocular pressures were normal in both eyes. On fundus examination, there were irregularly elevated discs bilaterally and the optic nerves appear with hazy disk margins. He did not have visual field defects in automated perimetry. Bilateral ODD were identified and confirmed by B-scan ultrasonography and optical coherence tomography (OCT demonstrated 4 clock hours of RNFL thickening. Optic disc drusen may be misdiagnosed as papilledema. Thus, clinical suspicion of ODD is important in order to diagnose papilledema and prevents unnecessary interventions. Although most of eyes with ODD have normal or thinner RNFL thickness, some of these eyes can have thicker RNFL thickness.

  1. Nano-scale Biophysical and Structural Investigations on Intact and Neuropathic Nerve Fibers by Simultaneous Combination of Atomic Force and Confocal Microscopy

    Science.gov (United States)

    Rosso, Gonzalo; Liashkovich, Ivan; Young, Peter; Shahin, Victor

    2017-01-01

    The links between neuropathies of the peripheral nervous system (PNS), including Charcot-Marie-Tooth1A and hereditary neuropathy with liability to pressure palsies, and impaired biomechanical and structural integrity of PNS nerves remain poorly understood despite the medical urgency. Here, we present a protocol describing simultaneous structural and biomechanical integrity investigations on isolated nerve fibers, the building blocks of nerves. Nerve fibers are prepared from nerves harvested from wild-type and exemplary PNS neuropathy mouse models. The basic principle of the designed experimental approach is based on the simultaneous combination of atomic force microscopy (AFM) and confocal microscopy. AFM is used to visualize the surface structure of nerve fibers at nano-scale resolution. The simultaneous combination of AFM and confocal microscopy is used to perform biomechanical, structural, and functional integrity measurements at nano- to micro-scale. Isolation of sciatic nerves and subsequent teasing of nerve fibers take ~45 min. Teased fibers can be maintained at 37°C in a culture medium and kept viable for up to 6 h allowing considerable time for all measurements which require 3–4 h. The approach is designed to be widely applicable for nerve fibers from mice of any PNS neuropathy. It can be extended to human nerve biopsies. PMID:28912683

  2. Nano-scale Biophysical and Structural Investigations on Intact and Neuropathic Nerve Fibers by Simultaneous Combination of Atomic Force and Confocal Microscopy

    Directory of Open Access Journals (Sweden)

    Gonzalo Rosso

    2017-08-01

    Full Text Available The links between neuropathies of the peripheral nervous system (PNS, including Charcot-Marie-Tooth1A and hereditary neuropathy with liability to pressure palsies, and impaired biomechanical and structural integrity of PNS nerves remain poorly understood despite the medical urgency. Here, we present a protocol describing simultaneous structural and biomechanical integrity investigations on isolated nerve fibers, the building blocks of nerves. Nerve fibers are prepared from nerves harvested from wild-type and exemplary PNS neuropathy mouse models. The basic principle of the designed experimental approach is based on the simultaneous combination of atomic force microscopy (AFM and confocal microscopy. AFM is used to visualize the surface structure of nerve fibers at nano-scale resolution. The simultaneous combination of AFM and confocal microscopy is used to perform biomechanical, structural, and functional integrity measurements at nano- to micro-scale. Isolation of sciatic nerves and subsequent teasing of nerve fibers take ~45 min. Teased fibers can be maintained at 37°C in a culture medium and kept viable for up to 6 h allowing considerable time for all measurements which require 3–4 h. The approach is designed to be widely applicable for nerve fibers from mice of any PNS neuropathy. It can be extended to human nerve biopsies.

  3. Corneal Cross-Linking for the Treatment of Keratoconus in a Patient with Ipsilateral Myelinated Retinal Nerve Fiber Layer

    Directory of Open Access Journals (Sweden)

    M. Leozappa

    2011-03-01

    Full Text Available Keratoconus associated with myelinated retinal nerve fibers is not frequent and the relationship between the two pathologies is difficult to explain, therefore studies and further investigation are required. The etiology of each condition may suggest the role of genetic factors. Follow-up is important to evaluate the progression of keratoconus and myelination. Here we describe the unusual coexistence of keratoconus and ipsilateral myelinated retinal nerve fiber layer and, for the first time, the corneal cross-linking treatment in this condition.

  4. Envelope coding in auditory nerve fibers following noise-induced hearing loss.

    Science.gov (United States)

    Kale, Sushrut; Heinz, Michael G

    2010-12-01

    Recent perceptual studies suggest that listeners with sensorineural hearing loss (SNHL) have a reduced ability to use temporal fine-structure cues, whereas the effects of SNHL on temporal envelope cues are generally thought to be minimal. Several perceptual studies suggest that envelope coding may actually be enhanced following SNHL and that this effect may actually degrade listening in modulated maskers (e.g., competing talkers). The present study examined physiological effects of SNHL on envelope coding in auditory nerve (AN) fibers in relation to fine-structure coding. Responses were compared between anesthetized chinchillas with normal hearing and those with a mild-moderate noise-induced hearing loss. Temporal envelope coding of narrowband-modulated stimuli (sinusoidally amplitude-modulated tones and single-formant stimuli) was quantified with several neural metrics. The relative strength of envelope and fine-structure coding was compared using shuffled correlogram analyses. On average, the strength of envelope coding was enhanced in noise-exposed AN fibers. A high degree of enhanced envelope coding was observed in AN fibers with high thresholds and very steep rate-level functions, which were likely associated with severe outer and inner hair cell damage. Degradation in fine-structure coding was observed in that the transition between AN fibers coding primarily fine structure or envelope occurred at lower characteristic frequencies following SNHL. This relative fine-structure degradation occurred despite no degradation in the fundamental ability of AN fibers to encode fine structure and did not depend on reduced frequency selectivity. Overall, these data suggest the need to consider the relative effects of SNHL on envelope and fine-structure coding in evaluating perceptual deficits in temporal processing of complex stimuli.

  5. Prevalence of Split Nerve Fiber Layer Bundles in Healthy People Imaged with Spectral Domain Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Sirel Gür Güngör

    2016-12-01

    Full Text Available Objectives: The presence of retinal nerve fiber layer (RNFL split bundles was recently described in normal eyes scanned using scanning laser polarimetry and by histologic studies. Split bundles may resemble RNFL loss in healthy eyes. The aim of our study was to determine the prevalence of nerve fiber layer split bundles in healthy people. Materials and Methods: We imaged 718 eyes of 359 healthy persons with the spectral domain optical coherence tomography in this cross-sectional study. All eyes had intraocular pressure of 21 mmHg or less, normal appearance of the optic nerve head, and normal visual fields (Humphrey Field Analyzer 24-2 full threshold program. In our study, a bundle was defined as ‘split’ when there is localized defect not resembling a wedge defect in the RNFL deviation map with a symmetrically divided RNFL appearance on the RNFL thickness map. The classification was performed by two independent observers who used an identical set of reference examples to standardize the classification. Results: Inter-observer consensus was reached in all cases. Bilateral superior split bundles were seen in 19 cases (5.29% and unilateral superior split was observed in 15 cases (4.16%. In 325 cases (90.52% there was no split bundle. Conclusion: Split nerve fiber layer bundles, in contrast to single nerve fiber layer bundles, are not common findings in healthy eyes. In eyes with normal optic disc appearance, especially when a superior RNFL defect is observed in RNFL deviation map, the RNLF thickness map and graphs should also be examined for split nerve fiber layer bundles.

  6. The majority of myelinated and unmyelinated sensory nerve fibers that innervate bone express the tropomyosin receptor kinase A.

    Science.gov (United States)

    Castañeda-Corral, G; Jimenez-Andrade, J M; Bloom, A P; Taylor, R N; Mantyh, W G; Kaczmarska, M J; Ghilardi, J R; Mantyh, P W

    2011-03-31

    Although skeletal pain is a leading cause of chronic pain and disability, relatively little is known about the specific populations of nerve fibers that innervate the skeleton. Recent studies have reported that therapies blocking nerve growth factor (NGF) or its cognate receptor, tropomyosin receptor kinase A (TrkA) are efficacious in attenuating skeletal pain. A potential factor to consider when assessing the analgesic efficacy of targeting NGF-TrkA signaling in a pain state is the fraction of NGF-responsive TrkA+ nociceptors that innervate the tissue from which the pain is arising, as this innervation and the analgesic efficacy of targeting NGF-TrkA signaling may vary considerably from tissue to tissue. To explore this in the skeleton, tissue slices and whole mount preparations of the normal, adult mouse femur were analyzed using immunohistochemistry and confocal microscopy. Analysis of these preparations revealed that 80% of the unmyelinated/thinly myelinated sensory nerve fibers that express calcitonin gene-related peptide (CGRP) and innervate the periosteum, mineralized bone and bone marrow also express TrkA. Similarly, the majority of myelinated sensory nerve fibers that express neurofilament 200 kDa (NF200) which innervate the periosteum, mineralized bone and bone marrow also co-express TrkA. In the normal femur, the relative density of CGRP+, NF200+ and TrkA+ sensory nerve fibers per unit volume is: periosteum>bone marrow>mineralized bone>cartilage with the respective relative densities being 100:2:0.1:0. The observation that the majority of sensory nerve fibers innervating the skeleton express TrkA+, may in part explain why therapies that block NGF/TrkA pathway are highly efficacious in attenuating skeletal pain. Copyright © 2011 IBRO. All rights reserved.

  7. [Clinical effect observation of biodegradable conduit small gap tublization repairing peripheral nerve injury].

    Science.gov (United States)

    Zhang, Pei-xun; Kou, Yu-hui; Han, Na; Dang, Yu; Xue, Feng; Wang, Tian-bing; Xu, Hai-lin; Chen, Jian-hai; Yang, Ming; Lu, Hao; Yin, Xiao-feng; Bai, Lu; Wang, Yan-hua; An, Shuai; Zhang, Dian-ying; Fu, Zhong-guo; Jiang, Bao-guo

    2012-12-18

    To observe the clinical effect of biodegradable conduit small gap tublization to repair peripheral nerve injury. In the study, 30 cases of fresh peripheral nerve injury in the upper extremities were recruited. After formally informed and obtaining the consent, the recruited patients were divided into the degradable chitin conduit tublization group (experimental group: 15 cases) and traditional epineurial neurorrhaphy group (control group: 15 cases). Their nerve functional recovery conditions were clinically observed according to the standard score methods provided by SHEN Ning-jiang and British Medical Research Council. The excellent and good rates of the overall nerve functional recovery were calculated. The electrophysiologic study was carried out after 6 months. Of the total 30 cases, 28 were followed up, and there were 14 cases in the degradable chitin conduit tublization group and traditional epineurial neurorrhaphy group. The operation procedure was very simple, and the mean suture time [(8.0±0.8) min] was 20% shorter than that of the traditional epineurial neurorrhaphy group [(10.0±0.6) min]. All the wounds in the degradable chitin conduit tublization group healed as expected without rejection, hypersensitive reaction or anomalous draining. Electrophysiology examination results after 6 months displayed that the sensory nerves conduction velocity recovery rate was 77.37% of the normal value, and motor nerve conduction velocity recovery rate was 70.09% in the degradable chitin conduit tublization group. The sensory nerves conduction velocity recovery rate was 61.69% of the normal value, and motor nerve conduction velocity recovery rate was 56.15% in the traditional epineurial neurorrhaphy group. The exact propability methods was applied in the comparison of sensory and motor nerve conduction velocity recovery rate, and there was no statistically significant of two groups(sensory nerve conduction velocity recovery rate P=0.678;motor nerve conduction velocity

  8. Autotaxin and lysophosphatidic acid1 receptor-mediated demyelination of dorsal root fibers by sciatic nerve injury and intrathecal lysophosphatidylcholine

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    Aoki Junken

    2010-11-01

    Full Text Available Abstract Background Although neuropathic pain is frequently observed in demyelinating diseases such as Guillain-Barré syndrome and multiple sclerosis, the molecular basis for the relationship between demyelination and neuropathic pain behaviors is poorly understood. Previously, we found that lysophosphatidic acid receptor (LPA1 signaling initiates sciatic nerve injury-induced neuropathic pain and demyelination. Results In the present study, we have demonstrated that sciatic nerve injury induces marked demyelination accompanied by myelin-associated glycoprotein (MAG down-regulation and damage of Schwann cell partitioning of C-fiber-containing Remak bundles in the sciatic nerve and dorsal root, but not in the spinal nerve. Demyelination, MAG down-regulation and Remak bundle damage in the dorsal root were abolished in LPA1 receptor-deficient (Lpar1-/- mice, but these alterations were not observed in sciatic nerve. However, LPA-induced demyelination in ex vivo experiments was observed in the sciatic nerve, spinal nerve and dorsal root, all which express LPA1 transcript and protein. Nerve injury-induced dorsal root demyelination was markedly attenuated in mice heterozygous for autotaxin (atx+/-, which converts lysophosphatidylcholine (LPC to LPA. Although the addition of LPC to ex vivo cultures of dorsal root fibers in the presence of recombinant ATX caused potent demyelination, it had no significant effect in the absence of ATX. On the other hand, intrathecal injection of LPC caused potent dorsal root demyelination, which was markedly attenuated or abolished in atx+/- or Lpar1-/- mice. Conclusions These results suggest that LPA, which is converted from LPC by ATX, activates LPA1 receptors and induces dorsal root demyelination following nerve injury, which causes neuropathic pain.

  9. A Model of Electrically Stimulated Auditory Nerve Fiber Responses with Peripheral and Central Sites of Spike Generation

    DEFF Research Database (Denmark)

    Joshi, Suyash Narendra; Dau, Torsten; Epp, Bastian

    2017-01-01

    A computational model of cat auditory nerve fiber (ANF) responses to electrical stimulation is presented. The model assumes that (1) there exist at least two sites of spike generation along the ANF and (2) both an anodic (positive) and a cathodic (negative) charge in isolation can evoke a spike. ...

  10. Directionality of auditory nerve fiber responses to pure tone stimuli in the grassfrog, Rana temporaria. II. Spike timing

    DEFF Research Database (Denmark)

    Jørgensen, M B; Christensen-Dalsgaard, J

    1997-01-01

    We studied the directionality of spike timing in the responses of single auditory nerve fibers of the grass frog, Rana temporaria, to tone burst stimulation. Both the latency of the first spike after stimulus onset and the preferred firing phase during the stimulus were studied. In addition, the ...

  11. Automatic estimation of retinal nerve fiber bundle orientation in SD-OCT images using a structure-oriented smoothing filter

    NARCIS (Netherlands)

    Ghafaryasl, B.; Baart, A.R.; de Boer, J.F.; Vermeer, K.A.; van Vliet, L.J.; Styner, Martin A.; Angelini, Elsa D.

    2017-01-01

    Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. A better understanding of retinal nerve fiber bundle (RNFB) trajectories in combination with visual field data may be used for future diagnosis and monitoring of glaucoma. However, manual tracing of

  12. The Effect of Pseudoexfoliation Syndrome on the Retinal Nerve Fiber Layer and Choroid Thickness.

    Science.gov (United States)

    Demircan, Süleyman; Yılmaz, Uğur; Küçük, Erkut; Ulusoy, M Döndü; Ataş, Mustafa; Gülhan, Ahmet; Zararsız, Gökmen

    2017-01-01

    To investigate thickness of the retinal nerve fiber layer (RNFL) and choroid thickness in patients with pseudoexfoliation syndrome (PEX) and pseudoexfoliation glaucoma (PXG) compared to healthy volunteers. This cross-sectional, prospective study included 43 patients with PXG, 45 patients with PEX syndrome, and 48 healthy volunteers. The RNFL and macular thickness were analyzed with standard OCT protocol while choroidal thickness was analyzed with EDI protocol in all subjects. The RNFL thickness was higher in the PEX and control groups compared to the PXG group (pthickness was significantly higher in the control group compared to the PXG and PEX groups (p<0.05). No significant difference was detected between the both groups. PEX might weaken choroid circulation by accumulating in choroid vessels. The thinner choroid in the PXG group suggests that ischemia affects the duration of PEX and has a role in the development of glaucoma.

  13. Retinal nerve fiber layer measurements by scanning laser polarimetry with enhanced corneal compensation in healthy subjects.

    Science.gov (United States)

    Rao, Harsha L; Venkatesh, Chirravuri R; Vidyasagar, Kelli; Yadav, Ravi K; Addepalli, Uday K; Jude, Aarthi; Senthil, Sirisha; Garudadri, Chandra S

    2014-12-01

    To evaluate the (i) effects of biological (age and axial length) and instrument-related [typical scan score (TSS) and corneal birefringence] parameters on the retinal nerve fiber layer (RNFL) measurements and (ii) repeatability of RNFL measurements with the enhanced corneal compensation (ECC) protocol of scanning laser polarimetry (SLP) in healthy subjects. In a cross-sectional study, 140 eyes of 73 healthy subjects underwent RNFL imaging with the ECC protocol of SLP. Linear mixed modeling methods were used to evaluate the effects of age, axial length, TSS, and corneal birefringence on RNFL measurements. One randomly selected eye of 48 subjects from the cohort underwent 3 serial scans during the same session to determine the repeatability. Age significantly influenced all RNFL measurements. RNFL measurements decreased by 1 µm for every decade increase in age. TSS affected the overall average RNFL measurement (β=-0.62, P=0.003), whereas residual anterior segment retardance affected the superior quadrant measurement (β=1.14, P=0.01). Axial length and corneal birefringence measurements did not influence RNFL measurements. Repeatability, as assessed by the coefficient of variation, ranged between 1.7% for the overall average RNFL measurement and 11.4% for th nerve fiber indicator. Age significantly affected all RNFL measurements with the ECC protocol of SLP, whereas TSS and residual anterior segment retardance affected the overall average and the superior average RNFL measurements, respectively. Axial length and corneal birefringence measurements did not influence any RNFL measurements. RNFL measurements had good intrasession repeatability. These results are important while evaluating the change in structural measurements over time in glaucoma patients.

  14. Scanning laser polarimetry and optical coherence tomography for detection of retinal nerve fiber layer defects.

    Science.gov (United States)

    Oh, Jong-Hyun; Kim, Yong Yeon

    2009-09-01

    To compare the ability of scanning laser polarimetry with variable corneal compensation (GDx-VCC) and Stratus optical coherence tomography (OCT) to detect photographic retinal nerve fiber layer (RNFL) defects. This retrospective cross-sectional study included 45 eyes of 45 consecutive glaucoma patients with RNFL defects in red-free fundus photographs. The superior and inferior temporal quadrants in each eye were included for data analysis separately. The location and presence of RNFL defects seen in red-free fundus photographs were compared with those seen in GDx-VCC deviation maps and OCT RNFL analysis maps for each quadrant. Of the 90 quadrants (45 eyes), 31 (34%) had no apparent RNFL defects, 29 (32%) had focal RNFL defects, and 30 (33%) had diffuse RNFL defects in red-free fundus photographs. The highest agreement between GDx-VCC and red-free photography was 73% when we defined GDx-VCC RNFL defects as a cluster of three or more color-coded squares (p<5%) along the traveling line of the retinal nerve fiber in the GDx-VCC deviation map (kappa value, 0.388; 95% confidence interval (CI), 0.195 to 0.582). The highest agreement between OCT and red-free photography was 85% (kappa value, 0.666; 95% CI, 0.506 to 0.825) when a value of 5% outside the normal limit for the OCT analysis map was used as a cut-off value for OCT RNFL defects. According to the kappa values, the agreement between GDx-VCC deviation maps and red-free photography was poor, whereas the agreement between OCT analysis maps and red-free photography was good.

  15. Peripapillary retinal nerve fiber layer changes in preclinical diabetic retinopathy: a meta-analysis.

    Directory of Open Access Journals (Sweden)

    Xiaofei Chen

    Full Text Available Diabetic retinopathy is a microvascular neurodegenerative disorder in diabetic patients. Peripapillary retinal nerve fiber layer changes have been described in patients with preclinical diabetic retinopathy, but study results have been inconsistent.To assess changes in peripapillary retinal nerve fiber layer thickness in diabetic patients with preclinical diabetic retinopathy.A literature search was conducted through PubMed, EMBASE, Web of Science and Cochrane Library. Case-control studies on RNFL thickness in preclinical diabetic retinopathy patients and healthy controls were retrieved. A meta-analysis of weighted mean difference and a sensitivity analysis were performed using RevMan 5.2 software.Thirteen case-control studies containing 668 diabetic patients and 556 healthy controls were selected. Peripapillary RNFL thickness was significantly reduced in patients with preclinical diabetic retinopathy compared to healthy controls in studies applying Optical Coherence Tomography (-2.88 μm, 95%CI: -4.44 to -1.32, P = 0.0003 and in studies applying Scanning Laser Polarimeter (-4.21 μm, 95%CI: -6.45 to -1.97, P = 0.0002. Reduction of RNFL thickness was significant in the superior quadrant (-3.79 μm, 95%CI: -7.08 to -0.50, P = 0.02, the inferior quadrant (-2.99 μm, 95%CI: -5.44 to -0.54, P = 0.02 and the nasal quadrant (-2.88 μm, 95%CI: -4.93 to -0.82, P = 0.006, but was not significant in the temporal quadrant (-1.22 μm, 95%CI: -3.21 to 0.76, P = 0.23, in diabetic patients.Peripapillary RNFL thickness was significantly decreased in preclinical diabetic retinopathy patients compared to healthy control. Neurodegenerative changes due to preclinical diabetic retinopathy need more attention.

  16. In-vivo imaging of retinal nerve fiber layer vasculature: imaging – histology comparison

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    Libby Richard T

    2009-08-01

    Full Text Available Abstract Background Although it has been suggested that alterations of nerve fiber layer vasculature may be involved in the etiology of eye diseases, including glaucoma, it has not been possible to examine this vasculature in-vivo. This report describes a novel imaging method, fluorescence adaptive optics (FAO scanning laser ophthalmoscopy (SLO, that makes possible for the first time in-vivo imaging of this vasculature in the living macaque, comparing in-vivo and ex-vivo imaging of this vascular bed. Methods We injected sodium fluorescein intravenously in two macaque monkeys while imaging the retina with an FAO-SLO. An argon laser provided the 488 nm excitation source for fluorescence imaging. Reflectance images, obtained simultaneously with near infrared light, permitted precise surface registration of individual frames of the fluorescence imaging. In-vivo imaging was then compared to ex-vivo confocal microscopy of the same tissue. Results Superficial focus (innermost retina at all depths within the NFL revealed a vasculature with extremely long capillaries, thin walls, little variation in caliber and parallel-linked structure oriented parallel to the NFL axons, typical of the radial peripapillary capillaries (RPCs. However, at a deeper focus beneath the NFL, (toward outer retina the polygonal pattern typical of the ganglion cell layer (inner and outer retinal vasculature was seen. These distinguishing patterns were also seen on histological examination of the same retinas. Furthermore, the thickness of the RPC beds and the caliber of individual RPCs determined by imaging closely matched that measured in histological sections. Conclusion This robust method demonstrates in-vivo, high-resolution, confocal imaging of the vasculature through the full thickness of the NFL in the living macaque, in precise agreement with histology. FAO provides a new tool to examine possible primary or secondary role of the nerve fiber layer vasculature in retinal

  17. Retinal nerve fiber layer axonal loss and visual dysfunction in optic neuritis.

    Science.gov (United States)

    Trip, S Anand; Schlottmann, Patricio G; Jones, Stephen J; Altmann, Daniel R; Garway-Heath, David F; Thompson, Alan J; Plant, Gordon T; Miller, David H

    2005-09-01

    Axonal loss is thought to be a likely cause of persistent disability after a multiple sclerosis relapse; therefore, noninvasive in vivo markers specific for axonal loss are needed. We used optic neuritis as a model of multiple sclerosis relapse to quantify axonal loss of the retinal nerve fiber layer (RNFL) and secondary retinal ganglion cell loss in the macula with optical coherence tomography. We studied 25 patients who had a previous single episode of optic neuritis with a recruitment bias to those with incomplete recovery and 15 control subjects. Optical coherence tomography measurement of RNFL thickness and macular volume, quantitative visual testing, and electrophysiological examination were performed. There were highly significant reductions (p color vision, and visual-evoked potential amplitude. This study has demonstrated functionally relevant changes indicative of axonal loss and retinal ganglion cell loss in the RNFL and macula, respectively, after optic neuritis. This noninvasive RNFL imaging technique could be used in trials of experimental treatments that aim to protect optic nerves from axonal loss.

  18. Optical coherence tomography evaluation of retinal nerve fiber layer in longitudinally extensive transverse myelitis

    Directory of Open Access Journals (Sweden)

    Frederico C. Moura

    2011-02-01

    Full Text Available OBJECTIVE: To compare optical coherence tomography (OCT measurements on the retinal nerve fiber layer (RNFL of healthy controls and patients with longitudinally extensive transverse myelitis (LETM without previous optic neuritis. METHOD: Twenty-six eyes from 26 patients with LETM and 26 control eyes were subjected to automated perimetry and OCT for comparison of RNFL measurements. RESULTS: The mean deviation values from perimetry were significantly lower in patients with LETM than in controls (p<0.0001. RNFL measurements in the nasal quadrant and in the 3-o'clock segment were significantly smaller in LETM eyes than in controls. (p=0.04 and p=0.006, respectively. No significantly differences in other RNFL measurements were found. CONCLUSION: Patients with LETM may present localized RNFL loss, particularly on the nasal side of the optic disc, associated with slight visual field defects, even in the absence of previous episodes of optic neuritis. These findings emphasize the fact that patients with LETM may experience attacks of subclinical optic nerve damage.

  19. Dermatomes in the rat limbs as determined by antidromic stimulation of sensory C-fibers in spinal nerves.

    Science.gov (United States)

    Takahashi, Y; Nakajima, Y

    1996-09-01

    Dermatomes of rats from C1 to T1 (forelimb) and from T12 to S2 (hindlimb) were determined by electrical stimulation of spinal nerves following the intravenous administration of Evans blue. After stimulation of the ventral ramus of a spinal nerve, a blue spotted area presenting the maximal innervation area of the spinal nerve appeared in the skin. Maximal innervation areas generally overlapped the adjacent areas. Each digit was innervated by two to three spinal nerves. Composite dermatomes were determined where boundary lines were defined as the midline of overlapping areas. Based on the composite dermatomes, boundary lines in the rat fore- and hindlimbs were revealed to loop around the antero-posterior axis showing a V-shaped pattern in the anterior and posterior aspects and converge to the ventral and dorsal midlines of the limb. The present dermatome chart may be applied to research concerning the segmental distribution of sensory C-fibers.

  20. Peripheral nerve injury and TRPV1-expressing primary afferent C-fibers cause opening of the blood-brain barrier

    Directory of Open Access Journals (Sweden)

    Salter Michael W

    2010-11-01

    Full Text Available Abstract Background The blood-brain barrier (BBB plays the crucial role of limiting exposure of the central nervous system (CNS to damaging molecules and cells. Dysfunction of the BBB is critical in a broad range of CNS disorders including neurodegeneration, inflammatory or traumatic injury to the CNS, and stroke. In peripheral tissues, the vascular-tissue permeability is normally greater than BBB permeability, but vascular leakage can be induced by efferent discharge activity in primary sensory neurons leading to plasma extravasation into the extravascular space. Whether discharge activity of sensory afferents entering the CNS may open the BBB or blood-spinal cord barrier (BSCB remains an open question. Results Here we show that peripheral nerve injury (PNI produced by either sciatic nerve constriction or transecting two of its main branches causes an increase in BSCB permeability, as assessed by using Evans Blue dye or horseradish peroxidase. The increase in BSCB permeability was not observed 6 hours after the PNI but was apparent 24 hours after the injury. The increase in BSCB permeability was transient, peaking about 24-48 hrs after PNI with BSCB integrity returning to normal levels by 7 days. The increase in BSCB permeability was prevented by administering the local anaesthetic lidocaine at the site of the nerve injury. BSCB permeability was also increased 24 hours after electrical stimulation of the sciatic nerve at intensity sufficient to activate C-fibers, but not when A-fibers only were activated. Likewise, BSCB permeability increased following application of capsaicin to the nerve. The increase in permeability caused by C-fiber stimulation or by PNI was not anatomically limited to the site of central termination of primary afferents from the sciatic nerve in the lumbar cord, but rather extended throughout the spinal cord and into the brain. Conclusions We have discovered that injury to a peripheral nerve and electrical stimulation of C-fibers

  1. Ganglioside GM3 synthase depletion reverses neuropathic pain and small fiber neuropathy in diet-induced diabetic mice.

    Science.gov (United States)

    Menichella, Daniela M; Jayaraj, Nirupa D; Wilson, Heather M; Ren, Dongjun; Flood, Kelsey; Wang, Xiao-Qi; Shum, Andrew; Miller, Richard J; Paller, Amy S

    2016-01-01

    Small fiber neuropathy is a well-recognized complication of type 2 diabetes and has been shown to be responsible for both neuropathic pain and impaired wound healing. In previous studies, we have demonstrated that ganglioside GM3 depletion by knockdown of GM3 synthase fully reverses impaired wound healing in diabetic mice. However, the role of GM3 in neuropathic pain and small fiber neuropathy in diabetes is unknown. Determine whether GM3 depletion is able to reverse neuropathic pain and small fibers neuropathy and the mechanism of the reversal. We demonstrate that GM3 synthase knockout and the resultant GM3 depletion rescues the denervation in mouse footpad skin and fully reverses the neuropathic pain in diet-induced obese diabetic mice. In cultured dorsal root ganglia from diet-induced diabetic mice, GM3 depletion protects against increased intracellular calcium influx in vitro. These studies establish ganglioside GM3 as a new candidate responsible for neuropathic pain and small fiber neuropathy in diabetes. Moreover, these observations indicate that systemic or topically applied interventions aimed at depleting GM3 may improve both the painful neuropathy and the wound healing impairment in diabetes by protecting against nerve end terminal degeneration, providing a disease-modifying approach to this common, currently intractable medical issue. © The Author(s) 2016.

  2. [CHANGES IN THE NUMBER OF REGENERATING MYELINATED FIBERS IN INJURED NERVE OF THE RAT AFTER ALLOTRANSPLANTATION OF THE DISSOCIATED CELLS OF THE EMBRYONIC CNS ANLAGES].

    Science.gov (United States)

    Petrova, Ye S; Isayeva, Ye N

    2015-01-01

    The study was conducted on 6 female and 36 male adult Wistar rats to compare the effects of dissociated cells derived from different embryonic CNS anlages, on the growth of regenerating nerve fibers in the damaged nerve of the recipient. After the sciatic nerve was damaged by ligation, part of the animals received the injection into the proximal portion of the nerve with a suspension of the cells obtained by dissociation of the fragments of spinal cord or forebrain vesicle taken from rat embryos at Day 15 of development. The analysis of transverse semithin sections of the distal part of the nerves was performed 21 and 60 days after surgery. It was found that the number of regenerating myelinated nerve fibers was increased 60 days after the injection of dissociated embryonic spinal cord cells, but not the neocortical cells into the damaged nerve of the recipient.

  3. The Use of Fiber-Reinforced Scaffolds Cocultured with Schwann Cells and Vascular Endothelial Cells to Repair Rabbit Sciatic Nerve Defect with Vascularization

    Directory of Open Access Journals (Sweden)

    Hongyang Gao

    2013-01-01

    Full Text Available To explore the feasibility of biodegradable fiber-reinforced 3D scaffolds with satisfactory mechanical properties for the repair of long-distance sciatic nerve defect in rabbits and effects of vascularized graft in early stage on the recovery of neurological function, Schwann cells and vascular endothelial cells were cocultured in the fiber-reinforced 3D scaffolds. Experiment group which used prevascularized nerve complex for the repair of sciatic nerve defect and control group which only cultured with Schwann cells were set. The animals in both groups underwent electromyography to show the status of the neurological function recovery at 4, 8, and 16 weeks after the surgery. Sciatic nerve regeneration and myelination were observed under the light microscope and electron microscope. Myelin sheath thickness, axonal diameter, and number of myelinated nerve fiber were quantitatively analyzed using image analysis system. The recovery of foot ulcer, the velocity of nerve conduction, the number of regenerating nerve fiber, and the recovery of ultrastructure were increased in the experimental group than those in the control group. Prevascularized tissue engineered fiber-reinforced 3D scaffolds for the repair of sciatic nerve defects in rabbits can effectively promote the recovery of neurological function.

  4. Α-Dendrotoxin-sensitive Kv1 channels contribute to conduction failure of polymodal nociceptive C-fibers from rat coccygeal nerve.

    Science.gov (United States)

    Wang, Xiu-Chao; Wang, Shan; Zhang, Ming; Gao, Fang; Yin, Chun; Li, Hao; Zhang, Ying; Hu, San-Jue; Duan, Jian-Hong

    2016-02-01

    It is known that some patients with diabetic neuropathy are usually accompanied by abnormal painful sensations. Evidence has accumulated that diabetic neuropathic pain is associated with the hyperexcitability of peripheral nociceptors. Previously, we demonstrated that reduced conduction failure of polymodal nociceptive C-fibers and enhanced voltage-dependent sodium currents of small dorsal root ganglion (DRG) neurons contribute to diabetic hyperalgesia. To further investigate whether and how potassium channels are involved in the conduction failure, α-dendrotoxin (α-DTX), a selective blocker of the low-threshold sustained Kv1 channel, was chosen to examine its functional capability in modulating the conduction properties of polymodal nociceptive C-fibers and the excitability of sensory neurons. We found that α-DTX reduced the conduction failure of C-fibers from coccygeal nerve in vivo accompanied by an increased initial conduction velocity but a decreased activity-dependent slowing of conduction velocity. In addition, the number of APs evoked by step currents was significantly enhanced after the treatment with α-DTX in small-diameter sensory neurons. Further study of the mechanism indicates α-DTX-sensitive K(+) current significantly reduced and the activation of this current in peak and steady state shifted to depolarization for diabetic neurons. Expression of Kv channel subunits Kv1.2 and Kv1.6 was downregulated in both small dorsal root ganglion neurons and peripheral C-fibers. Taken together, these results suggest that α-DTX-sensitive Kv1 channels might play an important role in regulating the conduction properties of polymodal nociceptive C-fibers and firing properties of sensory neurons. Copyright © 2016 the American Physiological Society.

  5. Imaging retinal nerve fiber bundles using optical coherence tomography with adaptive optics.

    Science.gov (United States)

    Kocaoglu, Omer P; Cense, Barry; Jonnal, Ravi S; Wang, Qiang; Lee, Sangyeol; Gao, Weihua; Miller, Donald T

    2011-08-15

    Early detection of axonal tissue loss in retinal nerve fiber layer (RNFL) is critical for effective treatment and management of diseases such as glaucoma. This study aims to evaluate the capability of ultrahigh-resolution optical coherence tomography with adaptive optics (UHR-AO-OCT) for imaging the RNFL axonal bundles (RNFBs) with 3×3×3μm(3) resolution in the eye. We used a research-grade UHR-AO-OCT system to acquire 3°×3° volumes in four normal subjects and one subject with an arcuate retinal nerve fiber layer defect (n=5; 29-62years). Cross section (B-scans) and en face (C-scan) slices extracted from the volumes were used to assess visibility and size distribution of individual RNFBs. In one subject, we reimaged the same RNFBs twice over a 7month interval and compared bundle width and thickness between the two imaging sessions. Lastly we compared images of an arcuate RNFL defect acquired with UHR-AO-OCT and commercial OCT (Heidelberg Spectralis). Individual RNFBs were distinguishable in all subjects at 3° retinal eccentricity in both cross-sectional and en face views (width: 30-50μm, thickness: 10-15μm). At 6° retinal eccentricity, RNFBs were distinguishable in three of the five subjects in both views (width: 30-45μm, thickness: 20-40μm). Width and thickness RNFB measurements taken 7months apart were strongly correlated (p<0.0005). Mean difference and standard deviation of the differences between the two measurement sessions were -0.1±4.0μm (width) and 0.3±1.5μm (thickness). UHR-AO-OCT outperformed commercial OCT in terms of clarity of the microscopic retina. To our knowledge, these are the first measurements of RNFB cross section reported in the living human eye. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Small fiber dysfunction in patients with Wilson's disease

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    Francisco de Assis A. Gondim

    2014-08-01

    Full Text Available Objective: Patients with Wilson’s disease (WD may develop a wide variety of neuropsychiatric symptoms, but there are few reports of autonomic dysfunction. Here, we described evidence of small fiber and/or autonomic dysfunction in 4 patients with WD and levodopa-responsive parkinsonism. Method: We reviewed the charts of 4 patients with WD who underwent evaluation for the presence of neuromuscular dysfunction and water-induced skin wrinkling test (SWT. Results: Two men and 2 women (33±3.5 years with WD were evaluated. They all had parkinsonism at some point during their disease course. Parkinsonism on patient 4 almost completely subsided with treatment of WD. Two patients had significant sensory and 2 significant autonomic complaints, including syncopal spells. NCS/EMG was normal in all but SWT was abnormal in half of them (mean 4-digit wrinkling of 0.25 and 1. Discussion: A subset of patients with WD exhibit evidence of abnormal skin wrinkling test (small fiber neuropathy.

  7. Spontaneous Regeneration of Nerve Fiber and Irreversibility of Corporal Smooth Muscle Fibrosis after Cavernous Nerve Crush Injury: Evidence From Serial Transmission Electron Microscopy and Intracavernous Pressure.

    Science.gov (United States)

    Wu, Yi-No; Chen, Kuo-Chiang; Liao, Chun-Hou; Chiang, Han-Sun

    2017-10-16

    To determine the pathophysiological progresses following bilateral cavernous nerve crushing (BCNC) injury, as an index for a treatment point and establishment of adequate treatment strategies for neurogenic erectile dysfunction (ED). Thirty-six rats were assigned to 1 of 6 groups, and BCNC or sham surgery was performed. Functional testing and ultrastructural analyses were performed immediately and at 7, 14, 21, and 28 d after the cavernous nerve (CN) injury (n = 6). Intracavernos pressure lowered progressively from 7 d to 14 d post-injury, and histological staining revealed that the number of neuronal nitric oxide synthase-positive nerve fibers on the dorsal penile nerve decreased significantly and progressively from 7 d until 21 d post-injury. Furthermore, ultrastructural analyses revealed axon loss and demyelination of the CN at 7 and 14 d post-injury. However, it is followed by partial spontaneous recovery of erectile function and regeneration of the CN at 28 d post-injury, suggesting that these time points may be useful for evaluating the effects of drug treatments. Furthermore, we found that CN injury-induced damage to corporal smooth muscle cells was irreversible; therefore, focusing on protecting the corpus cavernosum from apoptosis may be more important than nerve protection when assessing treatment mechanisms in the CN injury model. Our study makes a significant contribution to the human diagnostic pathology literature because it describes characteristics of relevant tissue in the rat, and provides information regarding time points that may be useful for future studies of pathological mechanisms or treatment evaluations. Copyright © 2017. Published by Elsevier Inc.

  8. Auditory brainstem responses predict auditory nerve fiber thresholds and frequency selectivity in hearing impaired chinchillas.

    Science.gov (United States)

    Henry, Kenneth S; Kale, Sushrut; Scheidt, Ryan E; Heinz, Michael G

    2011-10-01

    Noninvasive auditory brainstem responses (ABRs) are commonly used to assess cochlear pathology in both clinical and research environments. In the current study, we evaluated the relationship between ABR characteristics and more direct measures of cochlear function. We recorded ABRs and auditory nerve (AN) single-unit responses in seven chinchillas with noise-induced hearing loss. ABRs were recorded for 1-8 kHz tone burst stimuli both before and several weeks after 4 h of exposure to a 115 dB SPL, 50 Hz band of noise with a center frequency of 2 kHz. Shifts in ABR characteristics (threshold, wave I amplitude, and wave I latency) following hearing loss were compared to AN-fiber tuning curve properties (threshold and frequency selectivity) in the same animals. As expected, noise exposure generally resulted in an increase in ABR threshold and decrease in wave I amplitude at equal SPL. Wave I amplitude at equal sensation level (SL), however, was similar before and after noise exposure. In addition, noise exposure resulted in decreases in ABR wave I latency at equal SL and, to a lesser extent, at equal SPL. The shifts in ABR characteristics were significantly related to AN-fiber tuning curve properties in the same animal at the same frequency. Larger shifts in ABR thresholds and ABR wave I amplitude at equal SPL were associated with greater AN threshold elevation. Larger reductions in ABR wave I latency at equal SL, on the other hand, were associated with greater loss of AN frequency selectivity. This result is consistent with linear systems theory, which predicts shorter time delays for broader peripheral frequency tuning. Taken together with other studies, our results affirm that ABR thresholds and wave I amplitude provide useful estimates of cochlear sensitivity. Furthermore, comparisons of ABR wave I latency to normative data at the same SL may prove useful for detecting and characterizing loss of cochlear frequency selectivity. Copyright © 2011 Elsevier B.V. All

  9. Ulnar nerve stability-based surgery for cubital tunnel syndrome via a small incision: a comparison with classic anterior nerve transposition.

    Science.gov (United States)

    Kang, Ho-Jung; Koh, Il-Hyun; Chun, Yong-Min; Oh, Won-Taek; Chung, Kwang-Ho; Choi, Yun-Rak

    2015-08-06

    The purpose of this study was to compare the clinical outcomes of ulnar nerve stability-based surgery via a small incision with those of classic anterior transposition of the ulnar nerve for cubital tunnel syndrome. From March 2008 to December 2013, 107 patients with cubital tunnel syndrome underwent simple decompression or anterior transposition via a small incision, according to an ulnar nerve stability-based decision based on an assessment of intraoperative ulnar nerve stability (group A, n = 51), or anterior transposition via a classic incision (group B, n = 56). Clinical outcome was assessed using grip and pinch strength, two-point discrimination, the mean of the disabilities of arm, shoulder, and hand (DASH) survey, and the modified Bishop scale. At the final follow-up, all outcome measures improved significantly in both groups and there were no significant differences between the two groups. However, there were fewer operation-related complications in group A (one revision surgery) than in group B (one superficial infection, two painful scars, and five cases of numbness at the medial elbow). Outcomes after the ulnar nerve stability-based approach and anterior transposition were similar, although more patients experienced operation-related complications after anterior transposition via a classic incision. Making an ulnar nerve stability-based decision to perform either simple decompression or anterior transposition via a small incision seems to be a better strategy for patients with cubital tunnel syndrome.

  10. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica

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    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang, E-mail: njmu_wangdehang@126.com

    2015-04-15

    Highlights: •In the present study, we first elected ROIs corresponding to the proximal, medial, and distal levels of the lumbar foraminal zone. •The ROC analysis for FA values of distal nerves indicated a high level of reliability in the diagnosis of sciatica. •The declining trend of FA values from proximal to distal along the nerve tract may correlate with the disparity of axonal regeneration at different levels. •DTI is able to quantitatively evaluate compressed nerve roots and has a higher sensitivity and specificity for diagnosing sciatica than conventional MR imaging. •DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and probable localization of nerve compression. -- Abstract: Objective: To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Materials and methods: Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5–S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3–S1 nerve roots. ROC analysis was performed for FA values. Results: The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. Conclusions: DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica.

  11. Morphological changes of the peripheral nerves evaluated by high-resolution ultrasonography are associated with the severity of diabetic neuropathy, but not corneal nerve fiber pathology in patients with type 2 diabetes.

    Science.gov (United States)

    Ishibashi, Fukashi; Taniguchi, Miki; Kojima, Rie; Kawasaki, Asami; Kosaka, Aiko; Uetake, Harumi

    2015-05-01

    To evaluate the morphological changes of the median and posterior tibial nerve using high-resolution ultrasonography, and the corneal C fiber pathology by corneal confocal microscopy in type 2 diabetic patients. The cross-sectional area, hypoechoic area and maximum thickness of the nerve fascicle of both nerves were measured by high-resolution ultrasonography in 200 type 2 diabetic patients, stratified by the severity of diabetic neuropathy, and in 40 age- and sex-matched controls. These parameters were associated with corneal C fiber pathology visualized by corneal confocal microscopy, neurophysiological tests and severity of diabetic neuropathy. The cross-sectional area, hypoechoic area and maximum thickness of the nerve fascicle of both nerves in patients without diabetic neuropathy were larger than those in control subjects (P neuropathy (P neuropathy, and deteriorated only in patients with the most severe neuropathy. The association between the morphological changes of both nerves and corneal C fiber pathology was poor. The morphological changes in peripheral nerves of type 2 diabetic patients were found before the onset of neuropathy, and were closely correlated with the severity of diabetic neuropathy, but not with corneal C fiber pathology.

  12. Paradoxical thinning of the retinal nerve fiber layer after reversal of cupping: A case report of primary infantile glaucoma

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    Ta Chen Chang

    2016-01-01

    Full Text Available The circumpapillary retinal nerve fiber layer (RNFL thickness was assessed by spectral domain optical coherent tomography (SD-OCT before and after surgical reduction of intraocular pressure in an eye with primary infantile glaucoma. In this case, a postoperative reduction of cupping and a subsequent increase in neuroretinal rim area is associated with a paradoxical thinning of the RNFL. This is the first-known characterization of cupping reversal using SD-OCT.

  13. Changes in retinal nerve fiber layer thickness after spinal surgery in the prone position: a prospective study

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    Baran Gencer

    2015-02-01

    Full Text Available BACKGROUND AND OBJECTIVES: Changes in ocular perfusion play an important role in the pathogenesis of ischemic optic neuropathy. Ocular perfusion pressure is equal to mean arterial pressure minus intraocular pressure. The aim of this study was to evaluate the changes in the intraocular pressure and the retinal nerve fiber layer thickness in patients undergoing spinal surgery in the prone position. METHODS: This prospective study included 30 patients undergoing spinal surgery. Retinal nerve fiber layer thickness were measured one day before and after the surgery by using optical coherence tomography. Intraocular pressure was measured by tonopen six times at different position and time-duration: supine position (baseline; 10 min after intubation (Supine 1; 10 (Prone 1, 60 (Prone 2, 120 (Prone 3 min after prone position; and just after postoperative supine position (Supine 2. RESULTS: Our study involved 10 male and 20 female patients with the median age of 57 years. When postoperative retinal nerve fiber layer thickness measurements were compared with preoperative values, a statistically significant thinning was observed in inferior and nasal quadrants (p = 0.009 and p = 0.003, respectively. We observed a statistically significant intraocular pressure decrease in Supine 1 and an increase in both Prone 2 and Prone 3 when compared to the baseline. Mean arterial pressure and ocular perfusion pressure were found to be significantly lower in Prone 1, Prone 2 and Prone 3, when compared with the baseline. CONCLUSIONS: Our study has shown increase in intraocular pressure during spinal surgery in prone position. A statistically significant retinal nerve fiber layer thickness thinning was seen in inferior and nasal quadrants one day after the spinal surgery.

  14. Diffusion tensor imaging with quantitative evaluation and fiber tractography of lumbar nerve roots in sciatica.

    Science.gov (United States)

    Shi, Yin; Zong, Min; Xu, Xiaoquan; Zou, Yuefen; Feng, Yang; Liu, Wei; Wang, Chuanbing; Wang, Dehang

    2015-04-01

    To quantitatively evaluate nerve roots by measuring fractional anisotropy (FA) values in healthy volunteers and sciatica patients, visualize nerve roots by tractography, and compare the diagnostic efficacy between conventional magnetic resonance imaging (MRI) and DTI. Seventy-five sciatica patients and thirty-six healthy volunteers underwent MR imaging using DTI. FA values for L5-S1 lumbar nerve roots were calculated at three levels from DTI images. Tractography was performed on L3-S1 nerve roots. ROC analysis was performed for FA values. The lumbar nerve roots were visualized and FA values were calculated in all subjects. FA values decreased in compressed nerve roots and declined from proximal to distal along the compressed nerve tracts. Mean FA values were more sensitive and specific than MR imaging for differentiating compressed nerve roots, especially in the far lateral zone at distal nerves. DTI can quantitatively evaluate compressed nerve roots, and DTT enables visualization of abnormal nerve tracts, providing vivid anatomic information and localization of probable nerve compression. DTI has great potential utility for evaluating lumbar nerve compression in sciatica. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Perimetric and retinal nerve fiber layer findings in patients with Parkinson’s disease

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    Tsironi Evangelia E

    2012-10-01

    Full Text Available Abstract Background Visual dysfunction is common in Parkinson’s disease (PD. It remains, however, unknown whether it is related to structural alterations of the retina. The aim of this study is to compare visual field (VF findings and circumpapillary retinal nerve fiber layer (RNFL thickness in a series of PD patients and normal controls, in order to assess possible retinal anatomical changes and/or functional damage associated with PD. Methods PD patients and controls were recruited and underwent VF testing with static automated perimetry and RNFL examination with optical coherence tomography (OCT. Cognitive performance using Mini Mental State Examination (MMSE, PD staging using modified Hoehn and Yahr (H-Y scale and duration of the disease was recorded in PD patients. Results One randomly selected eye from each of 24 patients and 24 age-matched controls was included. OCT RNFL thickness analysis revealed no difference in the inferior, superior, nasal or temporal sectors between the groups. The average peripapillary RNFL was also similar in the two groups. However, perimetric indices of generalized sensitivity loss (mean deviation and localized scotomas (pattern standard deviation were worse in patients with PD compared to controls (p  Conclusion PD patients may demonstrate glaucomatous-like perimetric defects even in the absence of decreased RNFL thickness.

  16. Investigation of the effects of systemic isotretinoin treatment on retinal nerve fiber layer and macula.

    Science.gov (United States)

    Yılmaz, Uğur; Küçük, Erkut; Koç, Çağdaş; Özköse, Ayşe

    2017-06-01

    To investigate the effects of systemic isotretinoin therapy on retina by measuring retinal nerve fiber layer (RNFL) and macular thicknesses. This prospective, cross-sectional study was conducted in patients prescribed systemic isotretinoin therapy. Seventy-two eyes of 36 patients were included in the study. The patients were followed during three months. Detailed ophthalmologic examination including anterior and posterior segment examination, best corrected visual acuity and intraocular pressure measurement, RNFL and macular thicknesses measurement by Spectral Domain Cirrus Optical Coherence Tomography Model 400 (Carl Zeiss Meditech, Jena, Germany) were performed at baseline, first, second and third months after the beginning of systemic isotretinoin therapy in ophthalmology clinic. Thirty (83.3%) of the 36 patients were women and six (16.7%) of them were men. Mean age was 21.17 years. Mean RNFL thickness in the temporal quadrant at first, second, third months after beginning of treatment were found as significantly lower compared to baseline (p = .001). Mean macular thicknesses in superior outer, nasal outer and temporal outer quadrants at second and third months after beginning of treatment were found to be significantly lower compared to baseline and first month after beginning of treatment (p ≤ .001, .002 and .001, respectively). Macular thicknesses in superior inner quadrant at first, second and third months were found to be significantly lower than baseline values (p .05). The effect of oral isotretinoin therapy may cause regional thinning in RNFL and macula, directly visible part of central nervous system.

  17. Effect of oral isotretinoin treatment on retinal nerve fiber layer thickness.

    Science.gov (United States)

    Ucak, Haydar; Aykut, Veysel; Ozturk, Savas; Cicek, Demet; Erden, Ilker; Demir, Betul

    2014-01-01

    Oral isotretinoin treatment can cause ocular side effects. This study was performed to detect possible toxic effects of oral isotretinoin treatment on the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL). The study population consisted of 54 eyes of 27 patients with nodulocystic acne who used oral isotretinoin (Roaccutane) treatment. Macular GCL and peripapillary RNFL thickness measurements were performed using spectral domain optical coherence tomography (OCT) before and after therapy. Before and after treatment, a complete ophthalmologic examination was normal in all eyes. However, posttreatment lower temporal (TL) values were significantly lower (76.80 ± 16.31) than pretreatment TL values (84.96 ± 24.83) (p  =  .02). There was no statistically significant difference in the other OCT values, upper temporal, superotemporal, superonasal, upper nasal, lower nasal, inferonasal, and inferotemporal (p  =  .35, p  =  .40, p  =  .56, p  =  .95, p  =  .94, p  =  .93, p  =  .61, respectively). Also, there was no statistically significant difference between the right and left eyes and between genders for all parameters (p > .05). The use of oral isotretinoin treatment has increased in recent years. In addition, oral isotretinoin treatment has a broad adverse effect potential on the ocular system. The measurement of RNFL thickness, especially TL thickness, by OCT may be useful for detecting the possible toxic effect of oral isotretinoin therapy on RNFL.

  18. Scanning laser polarimetry quantification of retinal nerve fiber layer thinning following optic neuritis.

    Science.gov (United States)

    Trip, S Anand; Schlottmann, Patricio G; Jones, Stephen J; Kallis, Constantinos; Altmann, Daniel R; Garway-Heath, David F; Thompson, Alan J; Plant, Gordon T; Miller, David H

    2010-09-01

    Several studies with optical coherence tomography (OCT) have demonstrated thinning of the retinal nerve fiber layer (RNFL) in patients with optic neuritis and multiple sclerosis. Similar studies have not been performed with scanning laser polarimetry (SLP), which relies on different physical phenomena. This study was designed to use SLP to measure axonal loss following a single episode of optic neuritis and to determine if there is a relationship between the degree of axonal loss and the degree of residual visual dysfunction. Twenty-five patients with a single episode of optic neuritis and 15 control subjects were studied with SLP using the GDxVCC device to determine RNFL thickness in relation to visual acuity, visual fields, color vision, visual evoked potentials (VEPs), and previously published OCT data. SLP detected significant RNFL thinning in affected eyes compared to clinically unaffected fellow eyes in patients and in control eyes (P color vision. RNFL thinning correlated with reduced whole visual field and central visual field measures and VEP amplitudes. Superior and inferior quadrant RNFL thinning was related to corresponding regional visual field loss. There was a scaling factor between SLP and OCT RNFL measurements but only modest agreement. SLP detected functionally relevant axonal loss in eyes affected by optic neuritis. There was a scaling factor between RNFL measurements obtained with SLP and OCT but only modest agreement. Care should therefore be taken when comparing RNFL data from studies using these different devices.

  19. Predicted effects of sensorineural hearing loss on across-fiber envelope coding in the auditory nerve.

    Science.gov (United States)

    Swaminathan, Jayaganesh; Heinz, Michael G

    2011-06-01

    Cross-channel envelope correlations are hypothesized to influence speech intelligibility, particularly in adverse conditions. Acoustic analyses suggest speech envelope correlations differ for syllabic and phonemic ranges of modulation frequency. The influence of cochlear filtering was examined here by predicting cross-channel envelope correlations in different speech modulation ranges for normal and impaired auditory-nerve (AN) responses. Neural cross-correlation coefficients quantified across-fiber envelope coding in syllabic (0-5 Hz), phonemic (5-64 Hz), and periodicity (64-300 Hz) modulation ranges. Spike trains were generated from a physiologically based AN model. Correlations were also computed using the model with selective hair-cell damage. Neural predictions revealed that envelope cross-correlation decreased with increased characteristic-frequency separation for all modulation ranges (with greater syllabic-envelope correlation than phonemic or periodicity). Syllabic envelope was highly correlated across many spectral channels, whereas phonemic and periodicity envelopes were correlated mainly between adjacent channels. Outer-hair-cell impairment increased the degree of cross-channel correlation for phonemic and periodicity ranges for speech in quiet and in noise, thereby reducing the number of independent neural information channels for envelope coding. In contrast, outer-hair-cell impairment was predicted to decrease cross-channel correlation for syllabic envelopes in noise, which may partially account for the reduced ability of hearing-impaired listeners to segregate speech in complex backgrounds. © 2011 Acoustical Society of America

  20. Rates of progressive retinal nerve fiber layer loss in glaucoma measured by scanning laser polarimetry.

    Science.gov (United States)

    Medeiros, Felipe A; Zangwill, Linda M; Alencar, Luciana M; Sample, Pamela A; Weinreb, Robert N

    2010-06-01

    To evaluate rates of change measured with scanning laser polarimetry with enhanced corneal compensation (GDx ECC) and compare them to those measured using the variable corneal compensation (GDx VCC) method in a cohort of glaucoma patients and individuals suspected of having the disease followed over time. Observational cohort study. The study included 213 eyes of 213 patients with an average follow-up time of 4.5 years. Images were obtained annually with the GDx ECC and VCC, along with optic disc stereophotographs and standard automated perimetry (SAP) visual fields. Progression was determined by the Guided Progression Analysis software for SAP and by masked assessment of stereophotographs by expert graders. Joint linear mixed-effects models were used to evaluate rates of change in GDx measurements and their relationship with disease progression. Thirty-three patients (15%) showed progression over time on visual fields and/or stereophotographs. Mean rates of average retinal nerve fiber layer (RNFL) thickness change measured by the GDx ECC were significantly different in progressors versus nonprogressors (-1.24 microm/year vs -0.34 microm/year; P polarimetry. Copyright 2010 Elsevier Inc. All rights reserved.

  1. Retinal nerve fiber layer and ganglion cell complex thickness in patients with type 2 diabetes mellitus

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    Mehmet Demir

    2014-01-01

    Full Text Available Aim: The aim of the following study is to evaluate the retinal nerve fiber layer (RNFL and ganglion cell complex (GCC thickness in patients with type 2 diabetes mellitus (DM. Materials and Methods: Average, inferior, and superior values of RNFL and GCC thickness were measured in 123 patients using spectral domain optical coherence tomography. The values of participants with DM were compared to controls. Diabetic patients were collected in Groups 1, 2 and 3. Group 1 = 33 participants who had no diabetic retinopathy (DR; Group 2 = 30 participants who had mild nonproliferative DR and Group 3 = 30 participants who had moderate non-proliferative DR. The 30 healthy participants collected in Group 4. Analysis of variance test and a multiple linear regression analysis were used for statistical analysis. Results: The values of RNFL and GCC in the type 2 diabetes were thinner than controls, but this difference was not statistically significant. Conclusions: This study showed that there is a nonsignificant loss of RNFL and GCC in patients with type 2 diabetes.

  2. Macular and retinal nerve fiber thickness in recovered and persistent amblyopia.

    Science.gov (United States)

    Yassin, Sanaa A; Al-Tamimi, Elham R; Al-Hassan, Sultan

    2015-12-01

    The aim of this study was to investigate the presence of increased macular or retinal nerve fiber layer thickness (RNFLT) in amblyopic eyes, find if the increased macular or RNFLT is related to the lack of response in amblyopic eyes, and to explore whether the increased central macular thickness (CMT) in amblyopic eyes is purely related to the hyperopia. This is a prospective descriptive study. CMT and peripapillary RNFLT were measured by spectral-domain optical coherence tomography to evaluate 60 patients with unilateral-treated amblyopia (median age 11.00 year). Patients were divided into two groups: 33 patients in recovered amblyopia group and 27 patients in persistent amblyopia group. The mean CMT in the recovered group was 247.31 (±23.4) versus 246.8 (±32.7) µm (p = 0.95) for the persistent group. The mean peripapillary RNFLT was 99.13 (±12.1) versus 99.9 (±14.9) µm (p = 0.85) for the persistent group. In anisometropic amblyopia, there was no significant difference in CMT and RNFLT in either group. Also there was no relation between the type of refractive error and CMT or RNFLT. There was no significant difference in CMT and RNFLT in amblyopic eyes for both the recovered amblyopia group and the persistent amblyopia group to explain the lack of response in persistent amblyopic eyes. Additionally there was no relation between the type of refractive error and CMT or peripapillary RNFLT.

  3. Hyperbaric Oxygen Therapy Can Induce Angiogenesis and Regeneration of Nerve Fibers in Traumatic Brain Injury Patients

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    Sigal Tal

    2017-10-01

    Full Text Available Background: Recent clinical studies in stroke and traumatic brain injury (TBI victims suffering chronic neurological injury present evidence that hyperbaric oxygen therapy (HBOT can induce neuroplasticity.Objective: To assess the neurotherapeutic effect of HBOT on prolonged post-concussion syndrome (PPCS due to TBI, using brain microstructure imaging.Methods: Fifteen patients afflicted with PPCS were treated with 60 daily HBOT sessions. Imaging evaluation was performed using Dynamic Susceptibility Contrast-Enhanced (DSC and Diffusion Tensor Imaging (DTI MR sequences. Cognitive evaluation was performed by an objective computerized battery (NeuroTrax.Results: HBOT was initiated 6 months to 27 years (10.3 ± 3.2 years from injury. After HBOT, DTI analysis showed significantly increased fractional anisotropy values and decreased mean diffusivity in both white and gray matter structures. In addition, the cerebral blood flow and volume were increased significantly. Clinically, HBOT induced significant improvement in the memory, executive functions, information processing speed and global cognitive scores.Conclusions: The mechanisms by which HBOT induces brain neuroplasticity can be demonstrated by highly sensitive MRI techniques of DSC and DTI. HBOT can induce cerebral angiogenesis and improve both white and gray microstructures indicating regeneration of nerve fibers. The micro structural changes correlate with the neurocognitive improvements.

  4. Myelinated nerve fiber-associated local scleral excavation and induced axial myopia.

    Science.gov (United States)

    Oh, Baek-Lok; Hwang, Jeong-Min; Woo, Se Joon

    2014-10-01

    To investigate the association between the distributions of local scleral excavation and myelinated nerve fibers (MNF) and to elucidate the pathogenic mechanism of axial myopia in eyes with MNF. In six eyes of six pediatric patients with MNF, the distribution of the MNF on fundus photography was compared with the regional excavation of the sclera on linear scans across the fovea and a peripapillary circular scan of spectral domain optical coherence tomography. The tilting of Bruch membrane on vertical scan of spectral domain optical coherence tomography was associated with the major distribution of MNF (κ = 1, Cohen's kappa coefficient). The area of MNF of 12 clock-hour segments and focal scleral excavation on circular scan of spectral domain optical coherence tomography were significantly correlated (P excavation was strongly associated with the distribution of the MNF. This result indicates that the retinal areas deprived of visual stimulation by the MNF contribute to the development of axial myopia through local effects on the underlying sclera in early life.

  5. Correlation between peripapillary retinal nerve fiber layer thickness and visual function changes in patients receiving ethambutol

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    Dialika Dialika

    2015-04-01

    Full Text Available Background: Recent animal studies revealed the decreased amount of retinal ganglion cells after treatment with ethambutol. The aim of this study was to evaluate the changes of peripapillary retinal nerve fiber layer (RNFL thickness in patients receiving ethambutol therapy, as well as to know the correlation of RNFL thickness changes with the changes of visual function.Methods: This was a cohort study on 29 subjects at one tuberculosis treatment center, Jakarta. Subjects underwent RNFL thickness measurement using optical coherence tomography (OCT and several visual function parameters (visual acuity, contrast sensitivity, color sensitivity and visual field before and two-months following ethambutol therapy. Statistical comparison between pre- and post- ethambutol measurements were done using either paired T-test or Wilcoxon test. Correlations between anatomical and functional changes were assessed with Spearman correlation test. Results: There were significant changes of peripapillary RNFL thickness in superior (147 and 141 μm, p = 0.001, nasal (92 and 88 μm, p = 0.045 quadrants and average RNFL thickness (116.77 and 112.65 μm, p = 0.001. No significant correlation between RNFL thickness changes and the changes of visual function parameters (p > 0.05.Conclusion: Ethambutol consumption for two months in recommended dose is still considered safe to human retina and visual status.

  6. Macular and peripapillary retinal nerve fiber layer thickness in children with hyperopic anisometropic amblyopia

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    Shuang-Qing Wu

    2013-02-01

    Full Text Available AIM:To compare the retinal nerve fiber layer (RNFL thickness and macular thickness in the amblyopic eye with that in the sound eye of children with hyperopic anisometropic amblyopia using optical coherence tomography (OCT.METHODS: A prospective, nonrandom, intraindividual comparative cohort study includes 72 children with hyperopic anisometropic amblyopia in a single center. Macular thickness, macular foveola thickness, and peripapillary RNFL thickness were compared between the amblyopia eyes and the contralateral sound eyes.RESULTS:There were 38 male and 34 female patients, with a mean age as 9.7±1.9 years (range, 5–16 years. Hyperopic was +3.62±1.16D (range +2.00D to +6.50D in the amblyopic eyes, which was significantly higher in the control eyes with +0.76±0.90D (range 0D to +2.00D (P P = 0.02. The mean macular foveola thickness was significantly thicker in the amblyopic eyes than the contralateral sound eyes (181.4±14.2µm vs 175.2±13.3µm, P CONCLUSION:Eyes with hyperopic anisometropic amblyopia are found thicker macular foveola and peripapillary RNFL than the contralateral eyes in children.

  7. Neck transfixion for sacral extradural spinal meningeal cysts without spinal nerve root fibers.

    Science.gov (United States)

    Sun, Jian-Jun; Wang, Zhen-Yu; Liu, Bin; Li, Zhen-Dong; Wu, Hai-Bo; Yen, Ru-Yu; Zheng, Mei; Teo, Mario; Liu, Isabelle Yisha

    2016-06-01

    This prospective study analyzes clinical characteristics and outcomes of sacral extradural spinal meningeal cysts (SESMC) without spinal nerve root fibers (SNRF) undergoing neck transfixion. Using the relationship between the cysts and SNRF, SESMCs were divided into two types: cysts with SNRF known as Tarlov cysts and cysts without. If the SESMCs were identified as those without SNRFs, the neck of the cyst was transfixed, ligated and the remaining cyst wall removed distal to the clip. The improved Japanese Orthopedic Association (IJOA) scoring system was used to evaluate preoperative and postoperative neurological functions of the patients. Twenty-seven patients were included in this study. The average age was 42.7 ± 11.93 years. The mean preoperative IJOA score was 17.5 ± 2.47, and postoperative IJOA score was 19.1 ± 1.41. The difference between preoperative and postoperative IJOA scores was statistically significant (t = -3.75, P = 0.001), with a significant improvement in neurological function after surgery. Among the improvements in neurological function, the most significant was bowel/bladder function (z = -2.33, P = 0.02). Most patients experienced significant improvement in their neurological function after surgery. The most significant area of neurological improvement was bowel/bladder dysfunction, however, preoperative stool or urine incontinence did not recover completely.

  8. Progressive Retinal Nerve Fiber Layer Atrophy Associated With Enlarging Peripapillary Pit.

    Science.gov (United States)

    Lee, Eun Ji; Kim, Tae-Woo

    2017-02-01

    To report a case in which progressive retinal nerve fiber layer (RNFL) atrophy was observed along with enlargement of the peripapillary pit. A 34-year-old male was diagnosed with primary open-angle glaucoma and followed up for 4 years with regular ophthalmic examinations. Both eyes were myopic (-10 D, OD and -10.5 D, OS), and untreated intraocular pressures were 18 mm Hg (OD) and 16 mm Hg (OS). A subtle depression of the superotemporal peripapillary area was deepened and emerged as a peripapillary pit during the follow-up period. With the enlargement of the peripapillary pit, a RNFL defect at the location of pit widened and thinned continuously. The enlargement of the pit was documented by the spectral-domain optical coherence tomography posterior pole scanning. Progressive RNFL atrophy was observed with enlargement of the peripapillary pit. The finding suggests that tensile stress derived from the scleral stretching may have significant influence on the integrity of the RNFL.

  9. Analysis of the Retinal Nerve Fiber Layer in Retinitis Pigmentosa Using Optic Coherence Tomography

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    Medine Aslı Yıldırım

    2015-01-01

    Full Text Available Aim. To evaluate the peripapillary retinal nerve fiber layer (RNFL changes in retinitis pigmentosa (RP patients using spectral domain optic coherence tomography (Sd-OCT. Methods. We retrospectively examined medical records of forty-four eyes of twenty-two RP patients. The results were also compared with those of previously reported forty-four eyes of twenty-two normal subjects (controls. Records of average and four quadrants peripapillary RNFL thickness measurements using Sd-OCT were assessed. Results. In RP patients the mean RNFL thickness was 97.57 ± 3.21 μm. The RNFL in the superior, temporal, nasal, and inferior quadrants was 119.18 ± 4.47 μm, 84.68 ± 2.31 μm, 75.09 ± 3.34 μm, and 113.88 ± 4.25 μm, respectively. While the thinning of RNFL was predominantly observed in the inferior quadrant, the thickening was mostly noted in temporal quadrant. The differences between mean, superior, and nasal quadrant RNFL thicknesses were not statistically significant when compared with control group. The RP patients had thinner inferior quadrant and thicker temporal quadrant than control group (p<0.05. Conclusion. Sd-OCT is highly sensitive and effective instrument to detect RNFL changes in RP patients. RNFL measurements can provide information about the progression of retinitis pigmentosa and may provide prognostic indices for future treatment modalities.

  10. Analysis of the Retinal Nerve Fiber Layer in Retinitis Pigmentosa Using Optic Coherence Tomography

    Science.gov (United States)

    Yıldırım, Medine Aslı; Erden, Burak; Tetikoğlu, Mehmet; Kuru, Özlem; Elçioğlu, Mustafa

    2015-01-01

    Aim. To evaluate the peripapillary retinal nerve fiber layer (RNFL) changes in retinitis pigmentosa (RP) patients using spectral domain optic coherence tomography (Sd-OCT). Methods. We retrospectively examined medical records of forty-four eyes of twenty-two RP patients. The results were also compared with those of previously reported forty-four eyes of twenty-two normal subjects (controls). Records of average and four quadrants peripapillary RNFL thickness measurements using Sd-OCT were assessed. Results. In RP patients the mean RNFL thickness was 97.57 ± 3.21 μm. The RNFL in the superior, temporal, nasal, and inferior quadrants was 119.18 ± 4.47 μm, 84.68 ± 2.31 μm, 75.09 ± 3.34 μm, and 113.88 ± 4.25 μm, respectively. While the thinning of RNFL was predominantly observed in the inferior quadrant, the thickening was mostly noted in temporal quadrant. The differences between mean, superior, and nasal quadrant RNFL thicknesses were not statistically significant when compared with control group. The RP patients had thinner inferior quadrant and thicker temporal quadrant than control group (p treatment modalities. PMID:26351569

  11. Nerve terminal degeneration is independent of muscle fiber genotype in SOD1 mice.

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    Dario I Carrasco

    2010-03-01

    Full Text Available Motor neuron degeneration in SOD1(G93A transgenic mice begins at the nerve terminal. Here we examine whether this degeneration depends on expression of mutant SOD1 in muscle fibers.Hindlimb muscles were transplanted between wild-type and SOD1(G93A transgenic mice and the innervation status of neuromuscular junctions (NMJs was examined after 2 months. The results showed that muscles from SOD1(G93A mice did not induce motor terminal degeneration in wildtype mice and that muscles from wildtype mice did not prevent degeneration in SOD1(G93A transgenic mice. Control studies demonstrated that muscles transplanted from SOD1(G93A mice continued to express mutant SOD1 protein. Experiments on wildtype mice established that the host supplied terminal Schwann cells (TSCs at the NMJs of transplanted muscles.These results indicate that expression of the mutant protein in muscle is not needed to cause motor terminal degeneration in SOD1(G93A transgenic mice and that a combination of motor terminals, motor axons and Schwann cells, all of which express mutant protein may be sufficient.

  12. Effect of diabetic macular edema on peripapillary retinal nerve fiber layer thickness profiles.

    Science.gov (United States)

    Hwang, Duck Jin; Lee, Eun Ji; Lee, Sang Yoon; Park, Kyu Hyung; Woo, Se Joon

    2014-05-15

    To investigate both the effect of diabetic macular edema (DME) on measured peripapillary retinal nerve fiber layer (RNFL) thickness and the effect of intravitreal bevacizumab injection on RNFL thickness using spectral-domain optical coherence tomography (SD-OCT) in patients with diabetic retinopathy. We compared the SD-OCT RNFL thickness profiles between eyes with and without DME (DME [n = 42]; without DME [n = 53]) and conducted an interventional study for evaluating the effect of DME on RNFL thickness. Six sectorial and the global RNFL (gRNFL) thicknesses were compared between the two groups. To evaluate the intraindividual effect of DME on RNFL thickness, 1-month follow-up OCT data of 42 eyes that received an intravitreal bevacizumab injection were compared with preinjection data. The six sectorial and gRNFL thicknesses were greater in the DME group than the non-DME group (P thickness significantly correlated with the central foveal thickness (CFT) (R = 0.470, P thickness (P thickness and RNFL thickness were significantly correlated (R = 0.576, P thickness was generally increased in patients with DME, and the increment correlated with the degree of macular edema. While long-lasting DME resulted in RNFL thickening in all sectors, short-term DME resolution mainly influenced the temporal and nasal RNFL thicknesses. Cautious interpretation is recommended for evaluation of glaucoma using RNFL thickness in diabetic patients, especially patients with DME. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  13. Pathophysiology of Small-Fiber Sensory System in Parkinson's Disease: Skin Innervation and Contact Heat Evoked Potential.

    Science.gov (United States)

    Lin, Chin-Hsien; Chao, Chi-Chao; Wu, Shao-Wei; Hsieh, Paul-Chen; Feng, Fang-Ping; Lin, Yea-Huey; Chen, Ya-Mei; Wu, Ruey-Meei; Hsieh, Sung-Tsang

    2016-03-01

    Sensory symptoms are frequent nonmotor complaints in patients with Parkinson's disease (PD). However, few investigations integrally explored the physiology and pathology of the thermonociceptive pathway in PD. We aim to investigate the involvement of the thermonociceptive pathway in PD.Twenty-eight PD patients (16 men, with a mean age and standard deviation of 65.6 ± 10.7 years) free of neuropathic symptoms and systemic disorders were recruited for the study and compared to 23 age- and gender-matched control subjects (12 men, with a mean age and standard deviation of 65.1 ± 9.9 years). We performed skin biopsy, contact heat-evoked potential (CHEP), and quantitative sensory tests (QST) to study the involvement of the thermonociceptive pathway in PD.The duration of PD was 7.1 ± 3.2 (range 2-17 years) years and the UPDRS part III score was 25.6 ± 9.7 (range 10-48) during the off period. Compared to control subjects, PD patients had reduced intra-epidermal nerve fiber (IENF) density (2.48 ± 1.65 vs 6.36 ± 3.19 fibers/mm, P < 0.001) and CHEP amplitude (18.02 ± 10.23 vs 33.28 ± 10.48 μV, P < 0.001). Twenty-three patients (82.1%) had abnormal IENF densities and 18 (64.3%) had abnormal CHEP. Nine patients (32.1%) had abnormal thermal thresholds in the feet. In total 27 patients (96.4%) had at least 1 abnormality in IENF, CHEP, or thermal thresholds of the foot, indicating dysfunctions in the small-fiber nerve system. In control subjects, CHEP amplitude linearly correlated with IENF density (P < 0.001). In contrast, this relationship disappeared in PD (P = 0.312) and CHEP amplitude was negatively correlated with motor severity of PD independent of age, gender, and anti-PD medication dose (P = 0.036), suggesting the influences of central components on thermonociceptive systems in addition to peripheral small-fiber nerves in PD.The present study suggested impairment of small-fiber sensory system at both

  14. Sodium Channel Nav1.8 Underlies TTX-Resistant Axonal Action Potential Conduction in Somatosensory C-Fibers of Distal Cutaneous Nerves.

    Science.gov (United States)

    Klein, Amanda H; Vyshnevska, Alina; Hartke, Timothy V; De Col, Roberto; Mankowski, Joseph L; Turnquist, Brian; Bosmans, Frank; Reeh, Peter W; Schmelz, Martin; Carr, Richard W; Ringkamp, Matthias

    2017-05-17

    Voltage-gated sodium (Na V ) channels are responsible for the initiation and conduction of action potentials within primary afferents. The nine Na V channel isoforms recognized in mammals are often functionally divided into tetrodotoxin (TTX)-sensitive (TTX-s) channels (Na V 1.1-Na V 1.4, Na V 1.6-Na V 1.7) that are blocked by nanomolar concentrations and TTX-resistant (TTX-r) channels (Na V 1.8 and Na V 1.9) inhibited by millimolar concentrations, with Na V 1.5 having an intermediate toxin sensitivity. For small-diameter primary afferent neurons, it is unclear to what extent different Na V channel isoforms are distributed along the peripheral and central branches of their bifurcated axons. To determine the relative contribution of TTX-s and TTX-r channels to action potential conduction in different axonal compartments, we investigated the effects of TTX on C-fiber-mediated compound action potentials (C-CAPs) of proximal and distal peripheral nerve segments and dorsal roots from mice and pigtail monkeys ( Macaca nemestrina ). In the dorsal roots and proximal peripheral nerves of mice and nonhuman primates, TTX reduced the C-CAP amplitude to 16% of the baseline. In contrast, >30% of the C-CAP was resistant to TTX in distal peripheral branches of monkeys and WT and Na V 1.9 -/- mice. In nerves from Na V 1.8 -/- mice, TTX-r C-CAPs could not be detected. These data indicate that Na V 1.8 is the primary isoform underlying TTX-r conduction in distal axons of somatosensory C-fibers. Furthermore, there is a differential spatial distribution of Na V 1.8 within C-fiber axons, being functionally more prominent in the most distal axons and terminal regions. The enrichment of Na V 1.8 in distal axons may provide a useful target in the treatment of pain of peripheral origin. SIGNIFICANCE STATEMENT It is unclear whether individual sodium channel isoforms exert differential roles in action potential conduction along the axonal membrane of nociceptive, unmyelinated peripheral nerve

  15. The effect of pattern scan laser photocoagulation on peripapillary retinal nerve fiber layer thickness and optic nerve morphology in diabetic retinopathy.

    Science.gov (United States)

    Lee, Dong Eik; Lee, Ju Hyang; Lim, Han Woong; Kang, Min Ho; Cho, Hee Yoon; Seong, Mincheol

    2014-10-01

    To evaluate the effect of pattern scan laser (PASCAL) photocoagulation on peripapillary retinal nerve fiber layer (RNFL) thickness, central macular thickness (CMT), and optic nerve morphology in patients with diabetic retinopathy. Subjects included 35 eyes for the PASCAL group and 49 eyes for a control group. Peripapillary RNFL thickness, cup-disc area ratio and CMT were measured before PASCAL photocoagulation and at 2 and 6 months after PASCAL photocoagulation in the PASCAL or control groups. The average RNFL thickness had increased by 0.84 µm two months after and decreased by 0.4 µm six months after PASCAL photocoagulation compared to baseline, but these changes were not significant (p = 0.83, 0.39). The cup-disc area ratio was unchanged after PASCAL photocoagulation. CMT increased by 18.11 µm (p = 0.048) at two months compared to baseline thickness, and partially recovered to 11.82 µm (p = 0.11) at six months in the PASCAL group. PASCAL photocoagulation may not cause significant change in the peripapillary RNFL thickness, CMT, and optic nerve morphology in patients with diabetic retinopathy.

  16. Utility of skin biopsy in management of small fiber neuropathy.

    Science.gov (United States)

    Boruchow, Scott A; Gibbons, Christopher H

    2013-12-01

    We examined the role of skin biopsy in the evaluation and management of patients with suspected small fiber neuropathy (SFN). A retrospective chart review was performed among all patients who underwent skin biopsy for evaluation of SFN at our institution between March 2008 and March 2011. Change in management was defined as a new diagnosis or change in treatment in response to both positive and negative skin biopsies. Among 69 patients who underwent skin biopsy, 25 had pathological evidence of an SFN, and 9 had evidence of borderline SFN. Change in management or diagnosis occurred in 14 of 25 patients with definite SFN, 6 of 9 patients with borderline SFN, and 16 of 35 biopsy negative patients. Skin biopsy changed management or diagnosis in 52% of patients evaluated for a possible SFN and appears to play a valuable role in the workup of these patients. Copyright © 2013 Wiley Periodicals, Inc.

  17. Effect of testosterone on the number of NADPH diaphorase-stained nerve fibers in the rat corpus cavernosum and dorsal nerve.

    Science.gov (United States)

    Baba, K; Yajima, M; Carrier, S; Akkus, E; Reman, J; Nunes, L; Lue, T F; Iwamoto, T

    2000-09-01

    To elucidate the effect of testosterone on penile nerve supply. Three groups of 10 rats each were assessed; two groups were castrated and the third underwent a sham operation (control). After castration, one group received subcutaneous injection of testosterone while the others received sesame oil. At 8 weeks, the rats underwent a functional analysis. The evaluation included a subcutaneous injection with apomorphine to study centrally mediated erection, and cavernous nerve electrostimulation and papaverine injection to study peripherally mediated erection. At death, a penile midshaft specimen was taken for nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining. In the apomorphine study, castrated rats had no erections, but the erectile function of those receiving testosterone was restored to the level of the controls. The mean numbers of NADPH-diaphorase-stained nerve fibers in the copora cavernosa and both dorsal nerves of castrated rats, at 165.8 +/- 20.0 and 271.3 +/- 21.1, respectively, were significantly lower than those of the controls, at 271.7 +/- 14.6 and 471.2 +/- 27.6, respectively. Those of the testosterone replacement group, at 290.7 +/- 10.1 and 500.7 +/- 23.9, respectively, recovered to the control level. The intracavernosal pressure decreased significantly in the absence of testosterone, both after electrostimulation and intracavernosal papaverine injection, and recovered to the control level after testosterone replacement. Our results indicate that testosterone acts on the nervous system to mediate erection. When it is absent, there may be downregulation of both the production and activity of nitric oxide (NO), thereby decreasing the response to peripheral stimulation via the NO pathway. Testosterone replacement may upregulate NO activity to the control level.

  18. Internal-specific morphological analysis of sciatic nerve fibers in a radiofrequency-induced animal neuropathic pain model.

    Directory of Open Access Journals (Sweden)

    Samjin Choi

    Full Text Available This study investigated the reversible effects of pulsed radiofrequency (PRF treatment at 42 °C on the ultrastructural and biological changes in nerve and collagen fibers in the progression of neuropathic pain after rat sciatic nerve injury. Assessments of morphological changes in the extracellular matrices by atomic force microscopy and hematoxylin-eosin, Masson's trichrome and picrosirius-red staining as well as the expressions of two fibril-forming collagens, types-I and -III, and two inflammatory cytokines, TNF-α and IL-6, were evaluated on day 30 after RF exposure. There were four groups for different RF thermal treatments: no treatment, no current, PRF, and continuous RF (CRF. An RF procedure similar to that used in human clinical trials was used in this study. The CRF treatment at 82 °C led to neural and collagen damage by the permanent blockage of sensory nociceptors. The PRF treatment led to excellent performance and high expandability compared to CRF, with effects including slight damage and swelling of myelinated axons, a slightly decreased amount of collagen fibers, swelling of collagen fibril diameters, decreased immunoreactivity of collagen types-I and -III, presence of newly synthesized collagen, and recovery of inflammatory protein immunoreactivity. These evidence-based findings suggest that PRF-based pain relief is responsible for the temporary blockage of nerve signals as well as the preferential destruction of pain-related principal sensory fibers like the Aδ and C fibers. This suggestion can be supported by the interaction between the PRF-induced electromagnetic field and cell membranes; therefore, PRF treatment provides pain relief while allowing retention of some tactile sensation.

  19. Association Between Retinal Nerve Fiber Layer Thickness and Abnormalities of Vision in People With Human Immunodeficiency Virus Infection

    Science.gov (United States)

    Kalyani, Partho S.; Holland, Gary N.; Fawzi, Amani A.; Arantes, Tiago E.F.; Yu, Fei; Sadun, Alfredo A.

    2014-01-01

    Purpose To investigate relationships between contrast sensitivity (CS), color vision, and retinal nerve fiber layer (RNFL) among people with human immunodeficiency virus (HIV) infection; to evaluate the effect of time since diagnosis of HIV infection on RNFL thickness. Design Noninterventional cross-sectional study. Methods We evaluated 102 eyes of 57 HIV-infected individuals without ocular opportunistic infections. Peripapillary RNFL thickness was determined with spectraldomain optical coherence tomography in 4 quadrants. CS was measured with the Pelli-Robson technique (expressed as logCS); color vision was measured with the Lanthony desaturated 15-hue technique (expressed as color confusion index [C-index], with higher scores indicating worse color vision). Correlations between values were assessed using Spearman correlation coefficients. Results Median RNFL thickness (average of 4 quadrants) was 102.9 μm (range, 75.0–134.7 μm). Median logCS was 1.90 (range, 1.25–1.95). Median C-index was 1.58 (range, 0.96–4.07). Temporal RNFL thickness was correlated with logCS (r = 0.295, P = .003) and C-index (r = −0.338, P = .0005). Time since diagnosis of HIV infection was shorter for those with thick average RNFL than for those with thin average RNFL (P = .18). Conclusions Both worse CS and worse color vision are correlated with thinning of the temporal RNFL, with possible threshold effects. Increased prevalences of abnormal CS and abnormal color vision in this population are therefore likely attributable to neuroretinal compromise. This pattern of structural and functional losses may reflect preferential damage to small-caliber axons in the maculopapillary bundle, possibly associated with mitochondrial dysfunction, providing a potential disease mechanism for HIV-associated “neuroretinal disorder.” PMID:22245459

  20. [The Expression of Substance P in Sensory Neurons and Nerve Fibers Associated with "Sanyinjiao" (SP 6) Region in the Rat].

    Science.gov (United States)

    Zhang, Kun; Xu, Dong-sheng; Cui, Jing-jing; Zhang, Zhi-yun; Jing, Xiang-hong; Bai, Wan-zhu

    2015-12-01

    To explore the innervation and biochemical characteristics associated with acupoint "Sanyinjiao" (SP 6) in the rat by using neural tracing and immunofluorescence techniques. Five male SD rats were used in the present study. Alexa Fluor 488 conjugated cholera toxin subunit B (AF 488-CTB, 5 L, 1%) was injected into the site superior to the prominence of the medial malleolus, a corresponding site to acupoint SP 6 in the human body. After 3 surviving days, the rat's local tissue of SP 6 region, spinal cord and dorsal root ganglia (DRGs) at lumbar (L) segments (L 1 - S 1) were dissected following perfusion with 4% paraformaldehyde, cut into sections (20 μm for DRG and SP 6, and 40 μm for spinal cord) and observed under light microscope. In addition, substance P (SP) immunoreaction in the spinal cord, DRG and SP 6 region tissues was examined with immunofluorescence. All the labeling of AF 488-CTB appeared on the ipsilateral side of the injection. The labeled sensory and motor neurons distributed in L 3 - L 6 DRGs and spinal ventral horns with high concentration in the L 4 and L 5 segments. In addition, SP-positive neural labeling was found in small sensory neurons in DRG, axonal terminals in lamina I - II of spinal dorsal horns, and free nerve fibers in local subcutaneous tissues. Additionally, 24. 1 % of AF 488-CTB labeled sensory neurons simultaneously presented a SP-positive expression. These findings reveal that the sensory and motor neurons associated with acupoint SP 6 distribute in L 3- L 6 DRGs and spinal ventral horns of rats, concentrating in the L 4 and L 5 segments, and 24.1% sensory neurons show SP-positive, suggesting a possible involvement of the primary SP-positive sensory neurons in the transmission of acupuncture stimulation signals.

  1. Association between retinal nerve fiber layer thickness and abnormalities of vision in people with human immunodeficiency virus infection.

    Science.gov (United States)

    Kalyani, Partho S; Holland, Gary N; Fawzi, Amani A; Arantes, Tiago E F; Yu, Fei; Sadun, Alfredo A

    2012-04-01

    To investigate relationships between contrast sensitivity (CS), color vision, and retinal nerve fiber layer (RNFL) among people with human immunodeficiency virus (HIV) infection; to evaluate the effect of time since diagnosis of HIV infection on RNFL thickness. Noninterventional cross-sectional study. We evaluated 102 eyes of 57 HIV-infected individuals without ocular opportunistic infections. Peripapillary RNFL thickness was determined with spectral-domain optical coherence tomography in 4 quadrants. CS was measured with the Pelli-Robson technique (expressed as logCS); color vision was measured with the Lanthony desaturated 15-hue technique (expressed as color confusion index [C-index], with higher scores indicating worse color vision). Correlations between values were assessed using Spearman correlation coefficients. Median RNFL thickness (average of 4 quadrants) was 102.9 μm (range, 75.0-134.7 μm). Median logCS was 1.90 (range, 1.25-1.95). Median C-index was 1.58 (range, 0.96-4.07). Temporal RNFL thickness was correlated with logCS (r=0.295, P=.003) and C-index (r=-0.338, P=.0005). Time since diagnosis of HIV infection was shorter for those with thick average RNFL than for those with thin average RNFL (P=.18). Both worse CS and worse color vision are correlated with thinning of the temporal RNFL, with possible threshold effects. Increased prevalences of abnormal CS and abnormal color vision in this population are therefore likely attributable to neuroretinal compromise. This pattern of structural and functional losses may reflect preferential damage to small-caliber axons in the maculopapillary bundle, possibly associated with mitochondrial dysfunction, providing a potential disease mechanism for HIV-associated "neuroretinal disorder." Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Suppression Measured from Chinchilla Auditory-Nerve-Fiber Responses Following Noise-Induced Hearing Loss: Adaptive-Tracking and Systems-Identification Approaches.

    Science.gov (United States)

    Sayles, Mark; Walls, Michael K; Heinz, Michael G

    2016-01-01

    The compressive nonlinearity of cochlear signal transduction, reflecting outer-hair-cell function, manifests as suppressive spectral interactions; e.g., two-tone suppression. Moreover, for broadband sounds, there are multiple interactions between frequency components. These frequency-dependent nonlinearities are important for neural coding of complex sounds, such as speech. Acoustic-trauma-induced outer-hair-cell damage is associated with loss of nonlinearity, which auditory prostheses attempt to restore with, e.g., "multi-channel dynamic compression" algorithms.Neurophysiological data on suppression in hearing-impaired (HI) mammals are limited. We present data on firing-rate suppression measured in auditory-nerve-fiber responses in a chinchilla model of noise-induced hearing loss, and in normal-hearing (NH) controls at equal sensation level. Hearing-impaired (HI) animals had elevated single-fiber excitatory thresholds (by ~ 20-40 dB), broadened frequency tuning, and reduced-magnitude distortion-product otoacoustic emissions; consistent with mixed inner- and outer-hair-cell pathology. We characterized suppression using two approaches: adaptive tracking of two-tone-suppression threshold (62 NH, and 35 HI fibers), and Wiener-kernel analyses of responses to broadband noise (91 NH, and 148 HI fibers). Suppression-threshold tuning curves showed sensitive low-side suppression for NH and HI animals. High-side suppression thresholds were elevated in HI animals, to the same extent as excitatory thresholds. We factored second-order Wiener-kernels into excitatory and suppressive sub-kernels to quantify the relative strength of suppression. We found a small decrease in suppression in HI fibers, which correlated with broadened tuning. These data will help guide novel amplification strategies, particularly for complex listening situations (e.g., speech in noise), in which current hearing aids struggle to restore intelligibility.

  3. Agreement between automated and manual quantification of corneal nerve fiber length: Implications for diabetic neuropathy research.

    Science.gov (United States)

    Scarr, Daniel; Lovblom, Leif E; Ostrovski, Ilia; Kelly, Dylan; Wu, Tong; Farooqi, Mohammed A; Halpern, Elise M; Ngo, Mylan; Ng, Eduardo; Orszag, Andrej; Bril, Vera; Perkins, Bruce A

    2017-06-01

    Quantification of corneal nerve fiber length (CNFL) by in vivo corneal confocal microscopy represents a promising diabetic neuropathy biomarker, but applicability is limited by resource-intensive image analysis. We aimed to evaluate, in cross-sectional analysis of non-diabetic controls and patients with type 1 and type 2 diabetes with and without neuropathy, the agreement between manual and automated analysis protocols. Sixty-eight controls, 139 type 1 diabetes, and 249 type 2 diabetes participants underwent CNFL measurement (N=456). Neuropathy status was determined by clinical and electrophysiological criteria. CNFL was determined by manual (CNFLManual, reference standard) and automated (CNFLAuto) protocols, and results were compared for correlation and agreement using Spearman coefficients and the method of Bland and Altman (CNFLManual subtracted from CNFLAuto). Participants demonstrated broad variability in clinical characteristics associated with neuropathy. The mean age, diabetes duration, and HbA1c were 53±18years, 15.9±12.6years, and 7.4±1.7%, respectively, and 218 (56%) individuals with diabetes had neuropathy. Mean CNFLManual was 15.1±4.9mm/mm2, and mean CNFLAuto was 10.5±3.7mm/mm2 (CNFLAuto underestimation bias, -4.6±2.6mm/mm2 corresponding to -29±17%). Percent bias was similar across non-diabetic controls (-33±12%), type 1 (-30±20%), and type 2 diabetes (-28±16%) subgroups (ANOVA, p=0.068), and similarly in diabetes participants with and without neuropathy. Levels of CNFLAuto and CNFLManual were both inversely associated with neuropathy status. Although CNFLAuto substantially underestimated CNFLManual, its bias was non-differential between diverse patient groups and its relationship with neuropathy status was preserved. Determination of diagnostic thresholds specific to CNFLAuto should be pursued in diagnostic studies of diabetic neuropathy. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Peripapillary distribution of Muller cells within the retinal nerve fiber layer in human eyes.

    Science.gov (United States)

    Frenkel, Shahar; Goshen, Gal; Leach, Lu; Pe'er, Jacob; Mimouni, Michael; Blumenthal, Eytan Z

    2018-01-01

    The purpose of this study was to describe the distribution of Muller cell within the peripapillary retinal nerve fiber layer (RNFL) in human eyes. Eleven unpaired normal postmortem eyes were recruited into this study. Each eye was sectioned using the "umbrella technique" to obtain a concentric peripapillary ring centered on the optic disc, with a diameter of 3.0 mm. Immunohistochemistry with anti- CRALBP stained Muller cell within each ring. The RNFL thickness measurements around the peripapillary ring were: 262.5, 339.4, 285.4 and 347.5 μm for the temporal, superior, nasal and inferior quadrants, respectively. Muller cell were found to be unevenly distributed in the peripapillary RNFL of normal eyes. The relative Muller cell staining to the thickness of each measured segment (16.6%, 15.2%, 21.3%, and 17.9% for the temporal, superior, nasal and inferior quadrants, respectively) showed a significant increase in the nasal quadrant. The RNFL thickness measurements obtained using imaging techniques reflect the amount of axonal tissue present in this layer. In this study we highlight that around 20% of RNFL thickness is composed of non-axonal contents which do not represent neuronal tissue, nor are they necessarily lost in the glaucomatous process. More so, the ratio of the Muller cell component to the total RNFL thickness varies around the peripapillary RNFL ring, demonstrating the lowest relative content of Muller cell superiorly and the highest content nasally. Further studies should compare the amount and distribution of Muller cell in normal versus glaucomatous eyes. Copyright © 2017. Published by Elsevier Ltd.

  5. Impact of anatomical parameters on optical coherence tomography retinal nerve fiber layer thickness abnormality patterns

    Science.gov (United States)

    Baniasadi, Neda; Wang, Mengyu; Wang, Hui; Jin, Qingying; Mahd, Mufeed; Elze, Tobias

    2017-02-01

    Purpose: To evaluate the effects of four anatomical parameters (angle between superior and inferior temporal retinal arteries [inter-artery angle, IAA], optic disc [OD] rotation, retinal curvature, and central retinal vessel trunk entry point location [CRVTL]) on retinal nerve fiber layer thickness (RNFLT) abnormality marks by OCT machines. Methods: Cirrus OCT circumpapillary RNFLT measurements and Humphrey visual fields (HVF 24-2) of 421 patients from a large glaucoma clinic were included. Ellipses were fitted to the OD borders. Ellipse rotation relative to the vertical axis defined OD rotation. CRVTL was manually marked on the horizontal axis of the ellipse on the OCT fundus image. IAA was calculated between manually marked retinal artery locations at the 1.73mm radius around OD. Retinal curvature was determined by the inner limiting membrane on the horizontal B-scan closest to the OD center. For each location on the circumpapillary scanning area, logistic regression was used to determine if each of the four parameters had a significant impact on RNFLT abnormality marks independent of disease severity. The results are presented on spatial maps of the entire scanning area. Results: Variations in IAA significantly influenced abnormality marks on 38.8% of the total scanning area, followed by CRVTL (19.2%) and retinal curvature (18.7%). The effect of OD rotation was negligible (<1%). Conclusions: A natural variation in IAA, retinal curvature, and CRVTL can affect OCT abnormality ratings, which may bias clinical diagnosis. Our spatial maps may help OCT manufacturers to introduce location specific norms to ensure that abnormality marks indicate ocular disease instead of variations in eye anatomy.

  6. Comparison of retinal nerve fiber layer measurements between NTG and HTG using GDx-vCC.

    Science.gov (United States)

    Jung, J I Yong; Kim, Jae-hyung; Kook, Michael S

    2006-03-01

    To compare quantitative polarimetric measurements in eyes with NTG and HTG using GDx-VCC. Both groups were matched by age and glaucoma stage based on the Humphrey visual field test. We retrospectively reviewed the records of 146 patients who underwent Humphrey field analysis (HFA) and GDx-VCC. We compared outcomes of retinal nerve fiber layer (RNFL) parameters among the three groups by ANOVA and between each pair of groups using the Tukey-Kramer Post-Hoc test. We also evaluated the sensitivity and specificity of GDx-VCC in detecting glaucoma in each group. The mean age and HFA mean deviation (MD) were 55.6 +/- 9.5 years and -0.8 +/- 1.5 dB in 47 control patients, 59.4 +/- 9.0 years and -5.77 +/- 4.38 dB in 49 NTG patients, and 59.4 +/- 11.7 years and -8.09 +/- 6.77 dB in 51 HTG patients, respectively. All thickness parameters were lower in HTG patients compared to NTG patients, but there were no significant differences in ratio parameters between age-matched early HTG and NTG patients. The sensitivity of GDx-VCC was significantly higher in both early and total HTG patients compared to the respective groups of NTG patients. Compared to eyes with NTG, eyes with HTG showed reduced RNFL thickness and ratio parameters when patients were age and visual field matched. GDx-VCC appeared to be more sensitive in detecting RNFL damage in HTG patients.

  7. Corneal Hysteresis and Progressive Retinal Nerve Fiber Layer Loss in Glaucoma.

    Science.gov (United States)

    Zhang, Chunwei; Tatham, Andrew J; Abe, Ricardo Y; Diniz-Filho, Alberto; Zangwill, Linda M; Weinreb, Robert N; Medeiros, Felipe A

    2016-06-01

    To investigate the relationship between corneal hysteresis (CH) and progressive retinal nerve fiber layer (RNFL) loss in a cohort of patients with glaucoma followed prospectively over time. Prospective observational cohort study. One hundred and eighty-six eyes of 133 patients with glaucoma were followed for an average of 3.8 ± 0.8 years, with a median of 9 visits during follow-up. The CH measurements were acquired using the Ocular Response Analyzer (Reichert Instruments, Depew, New York, USA) and RNFL measurements were obtained at each follow up visit using spectral-domain optical coherence tomography (SDOCT). Random-coefficient models were used to investigate the relationship between baseline CH, central corneal thickness (CCT), average intraocular pressure (IOP), and rates of RNFL loss during follow-up, while adjusting for potentially confounding factors. Average baseline RNFL thickness was 76.4 ± 18.1 μm and average baseline CH was 9.2 ± 1.8 mm Hg. CH had a significant effect on rates of RNFL progression. In the univariable model, including only CH as a predictive factor along with time and their interaction, each 1 mm Hg lower CH was associated with a 0.13 μm/year faster rate of RNFL decline (P = .011). A similar relationship between low CH and faster rates of RNFL loss was found using a multivariable model accounting for age, race, average IOP, and CCT (P = .015). Lower CH was significantly associated with faster rates of RNFL loss over time. The prospective longitudinal design of this study provides further evidence that CH is an important factor to be considered in the assessment of the risk of progression in patients with glaucoma. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Retinal nerve fiber layer thickness in normal Indian pediatric population measured with optical coherence tomography

    Directory of Open Access Journals (Sweden)

    Neelam Pawar

    2014-01-01

    Full Text Available Purpose: To measure the peripapillary retinal nerve fiber layer (RNFL thickness in normal Indian pediatric population. Subjects and Methods: 120 normal Indian children ages 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. RNFL thickness was measured with stratus optical coherence tomography (OCT. Children with strabismus or amblyopia, with neurological, metabolic, vascular, or other disorders and those with abnormal optic discs were excluded. One eye of each subject was randomly selected for statistical analysis. The effect of age, refraction and gender on RNFL thickness was investigated statistically. Result: OCT measurements were obtained in 120 of 130 (92.3% subjects. Mean age was 10.8 ± 3.24 years (range 5-17. Average RNFL thickness was (± SD 106.11 ± 9.5 μm (range 82.26-146.25. The RNFL was thickest inferiorly (134.10 ± 16.16 μm and superiorly (133.44 ± 15.50 μm, thinner nasally (84.26 ± 16.43 μm, and thinnest temporally (70.72 ± 14.80 μm. In univariate regression analysis, age had no statistical significant effect on RNFL thickness (P = 0.7249 and refraction had a significant effect on RNFL thickness (P = 0.0008. Conclusion: OCT can be used to measure RNFL thickness in children. Refraction had an effect on RNFL thickness. In normal children, variation in RNFL thickness is large. The normative data provided by this study may assist in identifying changes in RNFL thickness in Indian children.

  9. Are All Retinal Nerve Fiber Layer Defects on Optic Coherence Tomography Glaucomatous?

    Directory of Open Access Journals (Sweden)

    Sirel Gür Güngör

    2017-12-01

    Full Text Available Objectives: In this study, we investigated the patients who were referred to our clinic with a prediagnosis of glaucoma based on retinal nerve fiber layer (RNFL defects on optic coherence tomography (OCT but were determined to have nonglaucomatous RNLF defects upon detailed examination. Materials and Methods: The ophthalmic examination notes, OCT images, Heidelberg retinal tomography (HRT II and fundus photographs of 357 patients were retrospectively evaluated. Final diagnoses of these patients were investigated. Results: Of the 357 patients, 216 (60.5% were diagnosed as open angle glaucoma, 33 (9.2% as low-tension glaucoma, 39 (10.9% as pre-perimetric glaucoma. The ophthalmic examinations of 14 patients (3.9% were normal and there were no RNFL defects in OCT examinations after dilatation. In 39 patients (10.9%, the ophthalmic and optic disc examinations were completely normal and no etiologic factor explaining RNFL defects was found. Twenty-two eyes of 16 patients (4.5% were included in this study (the mean age was 53.8±11.5 years; 9 men and 7 women. After detailed questioning of the medical history and systemic and neurologic examinations, a diagnosis of ischemic optic neuropathy was made in 11 eyes (10 patients (2.8%, optic neuritis in 3 eyes (2 patients (0.6%, optic disc drusen in 4 eyes (2 patients (0.6%, pseudotumor cerebri in 2 eyes (1 patient (0.3%, and cerebral palsy in 2 eyes (1 patient (0.3%. Conclusion: Decrease in RNFL thickness on OCT images alone may be misleading in glaucoma examination. In cases where optic disc cupping is not evident, diagnosis should not be based on OCT RNFL examinations alone, and the patient’s medical history, detailed ophthalmic examination, OCT optic disc parameters, HRT, and visual field tests should all be carefully evaluated together.

  10. Sex-specific differences in retinal nerve fiber layer thinning after acute optic neuritis.

    Science.gov (United States)

    Costello, Fiona; Hodge, William; Pan, Y Irene; Burton, Jodie M; Freedman, Mark S; Stys, Peter K; Trufyn, Jessie; Kardon, Randy

    2012-10-30

    The primary objective of this study was to explore the potential influence of gender on recovery from optic neuritis (ON) by determining whether differences in retinal nerve fiber layer (RNFL) thickness can be detected between men and women 6 months after an ON event. In this prospective cohort study, 39 men and 105 women with acute ON underwent repeat visual and optical coherence tomography (OCT) testing. The main outcome measures were change in RNFL measurements for male and female patients 6 months after ON. Men were older (mean age = 39 years) than women (35 years) (p = 0.05) in this study, and more men (62%) than women (41%) had a diagnosis of relapsing-remitting multiple sclerosis (MS) (p = 0.02). Because age and MS subtype were 2 significant covariates, both variables were controlled for in multiple regression analyses. Other covariates controlled for in the multivariate regression included disease duration (years), use of disease-modifying therapy (yes/no), and use of high-dose corticosteroids for acute ON (yes/no). After 6 months, mean RNFL values were lower in men (74 μm) than women (91 μm) (p Men showed more apparent change in RNFL thickness in their ON eyes from baseline to 6 months after ON than women (p = 0.003). There may be differences in recovery between men and women after ON, which can be difficult to detect with conventional visual testing. Our findings raise interesting questions about the potential influence of gender in MS, which may be explored in future studies.

  11. Retinal Nerve Fiber Layer Measures and Cognitive Function in the EPIC-Norfolk Cohort Study.

    Science.gov (United States)

    Khawaja, Anthony P; Chan, Michelle P Y; Yip, Jennifer L Y; Broadway, David C; Garway-Heath, David F; Luben, Robert; Hayat, Shabina; Matthews, Fiona E; Brayne, Carol; Khaw, Kay-Tee; Foster, Paul J

    2016-04-01

    We examined the relationship between retinal nerve fiber layer (RNFL) thickness and cognitive function in a population of older British adults. Participants of the European Prospective Investigation of Cancer (EPIC) Norfolk cohort study underwent ophthalmic and cognitive assessment. Measurements of RNFL thickness were made using the Heidelberg Retina Tomograph (HRT). Cognitive testing included a short form of the Mini-Mental State Examination (SF-MMSE), an animal naming task, a letter cancellation task, the Hopkins Verbal Learning Test (HVLT), the National Adult Reading Test (NART), and the Paired Associates Learning Test. Multivariable linear regression models were used to assess associations of RNFL thickness with cognitive test scores, adjusted for age, sex, education level, social class, visual acuity, axial length, and history of cataract surgery. Data were available from 5563 participants with a mean age of 67 years. A thicker HRT-derived RNFL thickness was associated with better scores for the SF-MMSE (0.06; 95% confidence interval [CI], [0.02, 0.10], P = 0.005), HVLT (0.16, 95% CI [0.03, 0.29]; P = 0.014), and NART (-0.24, 95% CI [-0.46, -0.02], P = 0.035). The associations of RNFL thickness with SF-MMSE and HVLT remained significant following further adjustment for NART. We found a significant association between HRT-derived RNFL thickness and scores from cognitive tests assessing global function, recognition, learning, episodic memory, and premorbid intelligence. However, the associations were weak and not currently of predictive value. Further research is required to confirm and clarify the nature of these associations, and identify biological mechanisms.

  12. Additive diagnostic role of imaging in glaucoma: optical coherence tomography and retinal nerve fiber layer photography.

    Science.gov (United States)

    Kim, Ko Eun; Kim, Seok Hwan; Oh, Sohee; Jeoung, Jin Wook; Suh, Min Hee; Seo, Je Hyun; Kim, Martha; Park, Ki Ho; Kim, Dong Myung

    2014-11-20

    To investigate the additive diagnostic role of spectral-domain optical coherence tomography (SD-OCT) and red-free retinal nerve fiber layer photography (RNFLP) in making clinical glaucoma diagnosis. Four diagnostic combination sets, including the most recent image from each measurement of 196 glaucoma eyes (including the 44 preperimetric glaucoma eyes) and 101 healthy eyes, were prepared: (1) stereo disc photography and Humphrey visual field (SH), (2) SH and SD-OCT (SHO), (3) SH and RNFLP (SHR), and (4) SHR and SD-OCT (SHRO). Each randomly sorted set was serially presented at 1-month intervals to five glaucoma specialists who were asked to evaluate them in a subjective and independent manner. The specialists' glaucoma-diagnostic performances based on the sets were then compared. For each specialist, adding SD-OCT to SH or SHR increased the glaucoma-diagnostic sensitivity but not to a level of statistical significance. For one specialist, adding RNFLP to SH significantly increased the sensitivity. Each specialist showed a high level of specificity regardless of the diagnostic set. The overall sensitivity of all specialists' assessments was significantly increased by adding RNFLP or the combination of SD-OCT and RNFLP to SH (P < 0.001); however, adding SD-OCT to SH or SHR did not significantly increase the sensitivity. A similar relationship was noted also for the preperimetric glaucoma subgroup. In contrast to RNFLP, SD-OCT did not significantly enhance the diagnostic accuracy of detecting glaucoma or even of preperimetric glaucoma. Our results suggest that, at least for glaucoma specialists, the additive diagnostic role of OCT is limited. Copyright 2014 The Association for Research in Vision and Ophthalmology, Inc.

  13. Microcystic Inner Nuclear Layer Changes and Retinal Nerve Fiber Layer Defects in Eyes with Glaucoma.

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    Tomoko Hasegawa

    Full Text Available To examine microcystic inner nuclear layer (INL changes in glaucomatous eyes and to determine associated factors.Retrospective, cross-sectional, observational study.Two hundred seventeen eyes of 133 patients with primary open angle glaucoma (POAG, 41 eyes of 32 patients with preperimetric glaucoma and 181 normal eyes of 117 subjects were ultimately included. Microcystic INL lesions were examined with infrared fundus images and with 19 vertical spectral domain optical coherence tomography (SD-OCT images in the macular area.Microcystic INL changes were observed in 6.0% of eyes with POAG, but none of the normal eyes or eyes with preperimetric glaucoma showed microcystic INL changes. The proportion of eyes with advanced glaucoma was significantly larger (P = 0.013 in eyes with microcystic lesions than without. The visual field mean deviation (MD slope was also significantly worse (P = 0.027 in eyes with microcystic lesions. No significant differences were observed in age, sex, refraction, axial length, intraocular pressure, or MD value between eyes with and without microcystic INL lesions. In several cases, microcystic INL lesions occurred along with glaucomatous visual field progression. The retinal nerve fiber layer (RNFL thickness (P = 0.013 and ganglion cell layer (GCL + inner plexiform layer thickness (P = 0.023 were significantly lower in areas with microcystic lesions than without. The INL was also significantly thicker (P = 0.002 in areas with microcystic lesions.Microcystic INL lesions in glaucomatous eyes are closely associated with RNFL and GCL thinning and correlated with worse MD slope. These INL lesions may indicate focal and progressive damage in glaucoma.

  14. Retinal Nerve Fiber Layer Measures and Cognitive Function in the EPIC-Norfolk Cohort Study

    Science.gov (United States)

    Khawaja, Anthony P.; Chan, Michelle P. Y.; Yip, Jennifer L. Y.; Broadway, David C.; Garway-Heath, David F.; Luben, Robert; Hayat, Shabina; Matthews, Fiona E.; Brayne, Carol; Khaw, Kay-Tee; Foster, Paul J.

    2016-01-01

    Purpose We examined the relationship between retinal nerve fiber layer (RNFL) thickness and cognitive function in a population of older British adults. Methods Participants of the European Prospective Investigation of Cancer (EPIC) Norfolk cohort study underwent ophthalmic and cognitive assessment. Measurements of RNFL thickness were made using the Heidelberg Retina Tomograph (HRT). Cognitive testing included a short form of the Mini-Mental State Examination (SF-MMSE), an animal naming task, a letter cancellation task, the Hopkins Verbal Learning Test (HVLT), the National Adult Reading Test (NART), and the Paired Associates Learning Test. Multivariable linear regression models were used to assess associations of RNFL thickness with cognitive test scores, adjusted for age, sex, education level, social class, visual acuity, axial length, and history of cataract surgery. Results Data were available from 5563 participants with a mean age of 67 years. A thicker HRT-derived RNFL thickness was associated with better scores for the SF-MMSE (0.06; 95% confidence interval [CI], [0.02, 0.10], P = 0.005), HVLT (0.16, 95% CI [0.03, 0.29]; P = 0.014), and NART (−0.24, 95% CI [−0.46, −0.02], P = 0.035). The associations of RNFL thickness with SF-MMSE and HVLT remained significant following further adjustment for NART. Conclusions We found a significant association between HRT-derived RNFL thickness and scores from cognitive tests assessing global function, recognition, learning, episodic memory, and premorbid intelligence. However, the associations were weak and not currently of predictive value. Further research is required to confirm and clarify the nature of these associations, and identify biological mechanisms. PMID:27092718

  15. Reflectance Decreases before Thickness Changes in the Retinal Nerve Fiber Layer in Glaucomatous Retinas

    Science.gov (United States)

    Zhou, Ye; Kong, Wei; Knighton, Robert W.

    2011-01-01

    Purpose. Glaucoma damages the retinal never fiber layer (RNFL). RNFL thickness, measured with optical coherence tomography (OCT), is often used in clinical assessment of the damage. In this study the relation between the RNFL reflectance and thickness at early stages of glaucoma was investigated. Methods. A rat model of glaucoma was used that involved laser photocoagulation of the trabecular meshwork. The reflectance of the RNFL in an isolated retina was measured, followed by immunohistochemical staining of the axonal cytoskeleton. RNFL thickness was measured by confocal fluorescence imaging. RNFL reflectance was calculated for bundle areas located at radii of 0.22, 0.33, and 0.44 mm from the optic nerve head (ONH) center. Linear regression was used to study the relation between reflectance and thickness. For glaucomatous eyes, only those bundles with no apparent structural damage were used. Results. Bundles in 11 control retinas and 10 treated retinas were examined. Bundle thickness of both groups at each radius was similar (P = 0.89). The reflectance of the bundles at radii of 0.33 and 0.44 mm was found to be similar in both control and treated retinas (P > 0.5). However, the reflectance of the bundles at the 0.22-mm radius decreased significantly in the treated group (P = 0.005). Conclusions. Elevation of intraocular pressure causes decrease in RNFL reflectance for bundles near the ONH. Change in RNFL reflectance precedes thinning of the RNFL. The results suggest that a decrease in RNFL reflectance near the ONH is an early sign of glaucomatous damage. PMID:21730345

  16. Assessment of retinal nerve fiber layer thickness with NFA-GDx following successful scleral buckling surgery.

    Science.gov (United States)

    Ozdek, S; Lonneville, Y; Onol, M; Gurelik, G; Hasanreisoglu, B

    2003-10-01

    To assess the effect of retinal detachment (RD) on retinal nerve fiber layer (RNFL) thickness by using a scanning laser polarimeter (NFA-GDx) after successful scleral buckling surgery for the treatment of rhegmatogenous RD. Consecutive patients who had successful scleral buckling surgery in one eye were assessed for RNFL thickness by using NFA-GDx prospectively. Fellow healthy eyes of the patients formed the control group. Eyes with RD surgery were compared with the control group with respect to three variables (superior average, inferior average, and average thickness) of NFA-GDx by using two-sampled t-test. Additionally, a possible effect of duration of RD on RNFL thickness was assessed with a correlation test. The study group consisted of 16 patients with a mean age of 49.8 years. The mean duration of RD was 28 days. Although the retardation values in operated eyes were less than that of the control eyes, the difference was not statistically significant (p > 0.05). However, these three values were seen to increase with increased duration of detachment and this correlation was statistically significant (R > 0.5, p < 0.03). RD seemed to cause minimal or no change in RNFL thickness as determined by GDx variables. The positive correlation between RNFL thickness and duration of RD, however, may be because of the proliferated Muller cells in eyes with RD, which may be responsible for some of the retardation measurements, which may be even more prominent in longstanding RD cases. This needs to be supported by further studies in larger patient groups with longer duration of RD and with histopathologic studies.

  17. Retinal Nerve Fiber Layer Thickness in Human T-cell Lymphotropic Virus Type 1 Patients.

    Science.gov (United States)

    Merle, Harold; Hage, Rabih; Jeannin, Séverine; Cabre, Philippe; Olindo, Stéphane

    2017-10-06

    To determine whether there is an optic neuropathy (ON) in patients with human T-cell lymphotropic virus type 1 (HTLV-1) infection. We included HTLV-1 asymptomatic carriers (a.c.HTLV-1) and tropical spastic paraparesis/HTLV-1 associated myelopathy (TSP/HAM) patients between January 1st, 2014 and March 31st, 2015. All patients had complete eye examination. The visual acuity (VA) and retinal nerve fiber layer (RNFL) thickness were measured and compared to age- and sex-matched control groups including patients seen in our refraction clinic with no previous medical or surgical history. Thirty-one a.c.HTLV-1 (group 1) and 29 TSP/HAM patients (group 2) were included. The average RNFL thickness was 99.9 ± 14.3 µm in group 1 and 87.8 ± 19.2 µm in group 2. The average RFNL thicknesses were lower in both groups, when compared to controls. The difference was significant in patients with TSP/HAM (87.8 ± 19.2 µm vs. 97 ± 7.8 µm; p = 0.003) who also had significantly decreased VA. We report here the first study about the RNFL thickness in patients with TSP/HAM. In these patients, there is decrease of the RNFL thickness with subtle but definite decrease of VA. This suggests that subclinical ON occurs in the natural history of the disease. The diagnosis of TSP/HAM must be evoked as a differential of primary progressive multiple sclerosis in a population at risk. Moreover, RNFL thinning with no evidence of glaucoma should raise suspicion for HTLV-1 infection and TSP/HAM in a population at risk.

  18. Effect of inhaled fluticasone propionate on retinal nerve fiber layer thickness in asthmatic children.

    Science.gov (United States)

    Dereci, Selim; Pirgon, Ozgur; Akcam, Mustafa; Turkyilmaz, Kemal; Dundar, Bumin

    2015-01-01

    Corticosteroids are under suspicion of playing an important role in the development of retinopathy. We aimed to determine peripapillary retinal nerve fiber layer (RNFL) thinning by spectral-domain optical coherence tomography (OCT) in children being treated with inhaled fluticasone propionate due to asthma. Thirty-eight children diagnosed with allergic asthma (mean age 9.8 ± 2.8 years, age range 6-13 years) and 40 age-similar controls were enrolled in this study. All children with asthma were taking inhaled fluticasone propionate at a dosage of 250 µg or more per day for at least 1 year. The RNFL thickness measurements were performed using Cirrus HD spectral-domain OCT 400. Central subfield thickness, cube average thickness, and cube volume were also measured. Among the 38 children with asthma and 40 healthy subjects who completed follow-up, children with asthma had similar mean peripapillary RNFL thicknesses compared with control children. The mean central subfield thickness was significantly higher than that of controls (248.8 ± 23.4 vs 237.5 ± 23.5, p<0.037). There was a positive linear relationship between cube average thickness and eosinophil count with a Pearson correlation coefficient of 0.336 (p<0.039) and a negative correlation was found between central subfield thickness and disease duration (r = -0.385, p = 0.017) in children with asthma. Asthmatic children have similar peripapillary RNFL measurements compared to controls on spectral-domain OCT. Raised eosinophil counts in asthmatic children were found to be significantly associated with cube average thickness.

  19. Visualization of nerve fiber orientation in gross histological sections of the human brain.

    Science.gov (United States)

    Axer, H; Berks, G; Keyserlingk, D G

    2000-12-01

    Diffusion weighted magnetic resonance imaging (DWMRI) allows visualization of the orientation of the nervous fibers in the living brain. For comparison, a method was developed to examine the orientation of fibers in histological sections of the human brain. Serial sections through the entire human brain were analyzed regarding fiber orientation using polarized light. Direction of fibers in the cutting plane was obtained by measuring the azimuth with the lowest intensity value at each point, and inclination of fibers in the section was evaluated using fuzzy logic approximations. Direction and inclination of fibers revealing their three-dimensional orientation were visualized by colored arrows mapped into the images. Using this procedure, various fiber tracts were identified (pyramidal tract, radiatio optica, radiatio acustica, arcuate fascicle, and 11 more). Intermingled fibers could be separated from each other. The orientation of the fiber tracts derived from polarized light microscopy was validated by confocal laser scanning microscopy in a defined volume of the internal capsule, where the fiber orientation was studied in four human brains. The polarization method visualizes the high degree of intermingled fiber bundles in the brain, so that distinct fiber pathways cannot be understood as solid, compact tracts: Neighbouring bundles of fibers can belong to different systems of fibers distinguishable by their orientation. Copyright 2000 Wiley-Liss, Inc.

  20. Quantification of retinal nerve fiber layer thickness using spectral domain optical coherence tomography in normal Indian population

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    Tarannum Mansoori

    2012-01-01

    Full Text Available The purpose of this study was to measure peripapillary retinal nerve fiber layer thickness (RNFLT using spectral domain optical coherence tomography (SD-OCT in normal Indian eyes, for which, 210 normal volunteers were recruited. One eye of each subject underwent RNFL scanning at 3.4 mm circle diameter around optic nerve using SD OCT. The data were analyzed to determine RNFLT in the sample population and its variation with age and gender. The average peripapillary RNFLT was 114.03 ± 9.59 μm. There was no effect of gender on RNFLT parameters. Age had significant negative correlation with average (P = 0.005, superior (P = 0.04, temporal (P = 0.049, and nasal quadrants (P = 0.01 RNFLT. Inferior quadrant RNFLT also had a negative correlation with age, but it was not statistically significant (P = 0.15.

  1. Facial Nerve Palsy: An Unusual Presenting Feature of Small Cell Lung Cancer

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    Ozcan Yildiz

    2011-01-01

    Full Text Available Lung cancer is the second most common type of cancer in the world and is the most common cause of cancer-related death in men and women; it is responsible for 1.3 million deaths annually worldwide. It can metastasize to any organ. The most common site of metastasis in the head and neck region is the brain; however, it can also metastasize to the oral cavity, gingiva, tongue, parotid gland and lymph nodes. This article reports a case of small cell lung cancer presenting with metastasis to the facial nerve.

  2. Evaluation of retinal nerve fiber layer thickness parameters in myopic population using scanning laser polarimetry (GDxVCC).

    Science.gov (United States)

    Dada, Tanuj; Aggarwal, A; Bali, S J; Sharma, A; Shah, B M; Angmo, D; Panda, A

    2013-01-01

    Myopia presents a significant challenge to the ophthalmologist as myopic discs are often large, tilted, with deep cups and have a thinner neuroretinal rim all of which may mimic glaucomatous optic nerve head changes causing an error in diagnosis. To evaluate the retinal fiber layer (RNFL) thickness in low, moderate and high myopia using scanning laser polarimetry with variable corneal compensation (GDxVCC). One hundred eyes of 100 emmetropes, 30 eyes of low myopes (0 to - 4 D spherical equivalent(SE), 45 eyes with moderate myopia (- 4 to - 8D SE), and 30 eyes with high myopia (- 8 to - 15D SE) were subjected to retinal nerve fiber layer assessment using the scanning laser polarimetry (GDxVCC) in all subjects using the standard protocol. Subjects with IOP > 21 mm Hg, optic nerve head or visual field changes suggestive of glaucoma were excluded from the study. The major outcome parameters were temporal-superior-nasal-inferiortemporal (TSNIT) average, the superior and inferior average and the nerve fibre indicator (NFI). The TSNIT average (p = 0.009), superior (p = 0.001) and inferior average (p = 0.008) were significantly lower; the NFI was higher (P less than 0.001) in moderate myopes as compared to that in emmetropes. In high myopia the RNFL showed supranormal values; the TSNIT average, superior and inferior average was significantly higher(p less than 0.001) as compared to that in emmetropes. The RNFL measurements on scanning laser polarimetry are affected by the myopic refractive error. Moderate myopes show a significant thinning of the RNFL. In high myopia due to peripapillary chorioretinal atrophy and contribution of scleral birefringence, the RNFL values are abnormally high. These findings need to be taken into account while assessing and monitoring glaucoma damage in moderate to high myopes on GDxVCC. © NEPjOPH.

  3. Creation of highly aligned electrospun poly-L-lactic acid fibers for nerve regeneration applications

    Science.gov (United States)

    Wang, Han Bing; Mullins, Michael E.; Cregg, Jared M.; Hurtado, Andres; Oudega, Martin; Trombley, Matthew T.; Gilbert, Ryan J.

    2009-02-01

    Aligned, electrospun polymer fibers have shown considerable promise in directing regenerating axons in vitro and in vivo. However, in several studies, final electrospinning parameters are presented for producing aligned fiber scaffolds, and alignment where minimal fiber crossing occurs is not achieved. Highly aligned species are necessary for neural tissue engineering applications to ensure that axonal extension occurs through a regenerating environment efficiently. Axonal outgrowth on fibers that deviate from the natural axis of growth may delay axonal extension from one end of a scaffold to the other. Therefore, producing aligned fiber scaffolds with little fiber crossing is essential. In this study, the contributions of four electrospinning parameters (collection disk rotation speed, needle size, needle tip shape and syringe pump flow rate) were investigated thoroughly with the goal of finding parameters to obtain highly aligned electrospun fibers made from poly-L-lactic acid (PLLA). Using an 8 wt% PLLA solution in chloroform, a collection disk rotation speed of 1000 revolutions per minute (rpm), a 22 gauge, sharp-tip needle and a syringe pump rate of 2 ml h-1 produced highly aligned fiber (1.2-1.6 µm in diameter) scaffolds verified using a fast Fourier transform and a fiber alignment quantification technique. Additionally, the application of an insulating sheath around the needle tip improved the rate of fiber deposition (electrospinning efficiency). Optimized scaffolds were then evaluated in vitro using embryonic stage nine (E9) chick dorsal root ganglia (DRGs) and rat Schwann cells (SCs). To demonstrate the importance of creating highly aligned scaffolds to direct neurite outgrowth, scaffolds were created that contained crossing fibers. Neurites on these scaffolds were directed down the axis of the aligned fibers, but neurites also grew along the crossed fibers. At times, these crossed fibers even stopped further axonal extension. Highly aligned PLLA fibers

  4. High-resolution imaging of the retinal nerve fiber layer in normal eyes using adaptive optics scanning laser ophthalmoscopy.

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    Kohei Takayama

    Full Text Available PURPOSE: To conduct high-resolution imaging of the retinal nerve fiber layer (RNFL in normal eyes using adaptive optics scanning laser ophthalmoscopy (AO-SLO. METHODS: AO-SLO images were obtained in 20 normal eyes at multiple locations in the posterior polar area and a circular path with a 3-4-mm diameter around the optic disc. For each eye, images focused on the RNFL were recorded and a montage of AO-SLO images was created. RESULTS: AO-SLO images for all eyes showed many hyperreflective bundles in the RNFL. Hyperreflective bundles above or below the fovea were seen in an arch from the temporal periphery on either side of a horizontal dividing line to the optic disc. The dark lines among the hyperreflective bundles were narrower around the optic disc compared with those in the temporal raphe. The hyperreflective bundles corresponded with the direction of the striations on SLO red-free images. The resolution and contrast of the bundles were much higher in AO-SLO images than in red-free fundus photography or SLO red-free images. The mean hyperreflective bundle width around the optic disc had a double-humped shape; the bundles at the temporal and nasal sides of the optic disc were narrower than those above and below the optic disc (P<0.001. RNFL thickness obtained by optical coherence tomography correlated with the hyperreflective bundle widths on AO-SLO (P<0.001 CONCLUSIONS: AO-SLO revealed hyperreflective bundles and dark lines in the RNFL, believed to be retinal nerve fiber bundles and Müller cell septa. The widths of the nerve fiber bundles appear to be proportional to the RNFL thickness at equivalent distances from the optic disc.

  5. Spontaneous activity of auditory nerve fibers in the barn owl (Tyto alba): analyses of interspike interval distributions.

    Science.gov (United States)

    Neubauer, Heinrich; Köppl, Christine; Heil, Peter

    2009-06-01

    In vertebrate auditory systems, the conversion from graded receptor potentials across the hair-cell membrane into stochastic spike trains of the auditory nerve (AN) fibers is performed by ribbon synapses. The statistics underlying this process constrain auditory coding but are not precisely known. Here, we examine the distributions of interspike intervals (ISIs) from spontaneous activity of AN fibers of the barn owl (Tyto alba), a nocturnal avian predator whose auditory system is specialized for precise temporal coding. The spontaneous activity of AN fibers, with the exception of those showing preferred intervals, is commonly thought to result from excitatory events generated by a homogeneous Poisson point process, which lead to spikes unless the fiber is refractory. We show that the ISI distributions in the owl are better explained as resulting from the action of a brief refractory period ( approximately 0.5 ms) on excitatory events generated by a homogeneous stochastic process where the distribution of interevent intervals is a mixture of an exponential and a gamma distribution with shape factor 2, both with the same scaling parameter. The same model was previously shown to apply to AN fibers in the cat. However, the mean proportions of exponentially versus gamma-distributed intervals in the mixture were different for cat and owl. Furthermore, those proportions were constant across fibers in the cat, whereas they covaried with mean spontaneous rate and with characteristic frequency in the owl. We hypothesize that in birds, unlike in mammals, more than one ribbon may provide excitation to most fibers, accounting for the different proportions, and that variation in the number of ribbons may underlie the variation in the proportions.

  6. Degeneration of auditory nerve fibers in guinea pigs with severe sensorineural hearing loss

    NARCIS (Netherlands)

    Kroon, Steven; Ramekers, Dyan; Smeets, Emma M; Hendriksen, Ferry G J; Klis, Sjaak F L; Versnel, Huib

    Damage to and loss of the organ of Corti leads to secondary degeneration of the spiral ganglion cell (SGC) somata of the auditory nerve. Extensively examined in animal models, this degeneration process of SGC somata following deafening is well known. However, degeneration of auditory nerve axons,

  7. Cupping reversal in pediatric glaucoma--evaluation of the retinal nerve fiber layer and visual field.

    Science.gov (United States)

    Ely, Amanda L; El-Dairi, Mays A; Freedman, Sharon F

    2014-11-01

    To identify optic nerve head (ONH) cupping reversal and associated optical coherence tomography (OCT) and Humphrey visual field changes in pediatric glaucoma. Retrospective observational case series. Sequential surgical cases of juvenile open-angle glaucoma (OAG) or primary congenital glaucoma (PCG) with sustained postoperative intraocular pressure (IOP) reduction. Group 1 had preoperative and postoperative ONH photographs and OCT; Group 2 had preoperative clinical ONH assessment and postoperative imaging. Cupping evaluation was confirmed by masked glaucoma and neuro-ophthalmology specialists. Of 80 cases, 9 eyes (9 children) met criteria for Group 1; 24 eyes (19 children) met criteria for Group 2. Group 1: Five of 9 eyes (56%) demonstrated cupping reversal, with preoperative vs postoperative mean IOP 34.2 ± 6.6 mm Hg vs 10.6 ± 4.1 mm Hg (P cupping reversal, with preoperative vs postoperative mean IOP 36.1 ± 8.9 mm Hg vs 13.3 ± 2.1 mm Hg (P cup-to-disc ratio. Limitations include small numbers, few reliable Humphrey visual fields, and absent preoperative imaging (Group 2). Some eyes with IOP reduction and ONH cupping reversal show continued RNFL thinning postoperatively. The preoperative ONH cup-to-disc ratio predicted the postoperative RNFL better than the postoperative "reversed and smaller" cup-to-disc ratio. Cupping reversal in pediatric glaucoma may not predict improved ONH health and deserves further study. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Peripapillary retinal nerve fiber layer thickness in different glaucoma stages measured by optical coherence tomography

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    Živković Maja

    2017-01-01

    Full Text Available Background/Aim. One of the most reliable methods for structural measurements of glaucomatous damage is spectral domain optical coherence tomography (SD-OCT. The aim of this study was to measure peripapillary retinal nerve fiber layer (RNFL thickness with SD-OCT in eyes with different stages of glaucoma, as well as to determine which sector in the peripapillary circle is the most vulnerable to glaucomatous damage. Methods. The study included 153 eyes of 93 patients with confirmed primary open angle glaucoma (POAG. All the patients underwent a complete ophthalmic examination, including visual field testing and peripapillary RNFL thickness measured by SD-OCT. They were divided into three subgroups: early, moderate and severe stage of glaucoma based on the mean deviation (MD index of visual field. The results were presented as mean RNFL thickness: total, in the four quadrants and 12 clock-hour RNFL thickness. Results. The overall mean peripapillary RNFL was 74.95 ± 14.51 μm. The lower quadrant had the thickest RNFL (92.78 ± 25.84 μm, followed by upper (88.82 ± 22.04 μm, nasal (64.31 ± 11.67 μm and temporal ones (54.02 ± 12.76 μm, showing a significant difference (χ2 = 273.36, DF = 3, p < 0.001. Comparison between RNFL thickness in early glaucoma and moderate and severe stages revealed that the most sensitive sectors were inferior and superior ones, as well as sectors at 5–7 clock hour position. The greatest decrease in RNFL thickness was observed in the 9 o'clock hour sector in all three glaucoma subgroups (46.99 ± 13.28 μm, while the RNFL was the thickest in the 6 o'clock hour sector (102.63 ± 34.12 μm. Conclusion. Peripapillary RNFL thickness is inversely proportional to the degree of glaucomatous damage: the greater the damage, the thinner peripapillary RNFL.

  9. Synchronized reconstitution of muscle fibers, peripheral nerves and blood vessels by murine skeletal muscle-derived CD34(-)/45 (-) cells.

    Science.gov (United States)

    Tamaki, Tetsuro; Okada, Yoshinori; Uchiyama, Yoshiyasu; Tono, Kayoko; Masuda, Maki; Wada, Mika; Hoshi, Akio; Akatsuka, Akira

    2007-10-01

    In order to establish the practical isolation and usage of skeletal muscle-derived stem cells (MDSCs), we determined reconstitution capacity of CD34(-)/CD45(-) (Sk-DN) cells as a candidate somatic stem cell source for transplantation. Sk-DN cells were enzymatically isolated from GFP transgenic mice (C57/BL6N) skeletal muscle and sorted using fluorescence activated cell sorting (FACS), and expanded by collagen gel-based cell culture with bFGF and EGF. The number of Sk-DN cells was small after sorting (2-8 x 10(4)); however, the number increased 10-20 fold (2-16 x 10(5)) after 6 days of expansion culture, and the cells maintained immature state and multipotency, expressing mRNAs for mesodermal and ectodermal cell lineages. Transplantation of expanded Sk-DN cells into the severe muscle damage model (C57/BL6N wild-type) resulted in the synchronized reconstitution of blood vessels, peripheral nerves and muscle fibers following significant recovery of total muscle mass (57%) and contractile function (55%), whereas the non-cell-transplanted control group showed around 20% recovery in both factors. These reconstitution capacities were supported by the intrinsic plasticity of Sk-DN cells that can differentiate into muscular (skeletal muscle), vascular (pericyte, endothelial cell and smooth muscle) and peripheral nerve (Schwann cells and perineurium) cell lineages that was revealed by transplantation to non-muscle tissue (beneath renal capsule) and fluorescence in situ hybridization (FISH) analysis.

  10. Distal leg epidermal nerve fiber density as a surrogate marker of HIV-associated sensory neuropathy risk: risk factors and change following initial antiretroviral therapy.

    Science.gov (United States)

    Shikuma, Cecilia M; Bennett, Kara; Ananworanich, Jintanat; Gerschenson, Mariana; Teeratakulpisarn, Nipat; Jadwattanakul, Tanate; DeGruttola, Victor; McArthur, Justin C; Ebenezer, Gigi; Chomchey, Nitiya; Praihirunkit, Pairoa; Hongchookiat, Piranun; Mathajittiphun, Pornpen; Nakamoto, Beau; Hauer, Peter; Phanuphak, Praphan; Phanuphak, Nittaya

    2015-10-01

    Distal leg epidermal nerve fiber density (ENFD) is a validated predictor of HIV sensory neuropathy (SN) risk. We assessed how ENFD is impacted by initiation of first-time antiretroviral therapy (ART) in subjects free of neuropathy and how it is altered when mitochondrial toxic nucleoside medications are used as part of ART. Serial changes in proximal thigh and distal leg ENFD were examined over 72 weeks in 150 Thai subjects randomized to a regimen of stavudine (d4T) switching to zidovudine (ZDV) at 24 weeks vs ZDV vs tenofovir (TDF) for the entire duration of study, all given in combination with nevirapine. We found individual variations in ENFD change, with almost equal number of subjects who decreased or increased their distal leg ENFD over 72 weeks and no relationship to nucleoside backbone or to development of neuropathic signs or symptoms. Lower baseline distal leg ENFD and greater increases in mitochondrial oxidative phosphorylation complex I (CI) activity were associated with larger increases in distal leg ENFD over 72 weeks. Distal leg ENFD correlated with body composition parameters (body surface area, body mass index, height) as well as with blood pressure measurements. Assessed together with a companion cross-sectional study, we found that mean distal leg ENFD in all HIV+ subjects was lower than in HIV- subjects but similar among HIV+ groups whether ART-naïve or on d4T with/without neuropathy/neuropathic symptoms. The utility of ENFD as a useful predictor of small unmyelinated nerve fiber damage and neuropathy risk in HIV may be limited in certain populations.

  11. Computerized image recognition for morphometry of nerve attribute of shape of sampled transverse sections of myelinated fibers which best estimates their average diameter.

    Science.gov (United States)

    Karnes, J; Robb, R; O'Brien, P C; Lambert, E H; Dyck, P J

    1977-10-01

    A computerized image recognition method was used to measure various attributes of shape of cross-sections of myelinated nerve fibers. Measurements were made at intervals over 1/2 internode of each fiber on 20 fibers from each of 4 sural nerves from rats. Diameters were computed in 6 different ways from the computer measurements and compared for bias, precision, and accuracy between sections and to the diameter of an idealized cylinder reconstructed for each fiber from multiple actual cross sections. The diameter computed from cross-sectional areas of transversely sectioned myelinated fibers, converted into a circle, showed the highest precision, greatest accuracy and least bias. Fibers were classified by shape and the frequency was determined in defined regions (I1 = paranodal, I3= nuclear and I2=region between I1 and I3) of the 1/2 internode. A crenated shape is highly characteristic of the I1 region. The boomerang shape was found most frequently in I3 whereas the circular shape was found most frequently in I2. Epileptical and boomerang shapes of myelinated fibers within fascicles which have been orientated carefully to obtain transverse sections, are not due to obliquity of section. Therefore, using the minor axis to determine the diameter of such profiles, as we had done previously in our laboratory, is in error. We conclude from these studies, that in carefully orientated transverse sections of nerve trucks, the diameter calculated from measurement of area converted to a circular shape is the best among the various estimates of myelinated fiber diameter and is the most suitable one for use in computerized image recognition systems for nerve morphometry. It seems reasonable to extrapolate this general conclusion to myelinated fibers of man.

  12. Retinal nerve fiber layer thinning in dementia associated with Parkinson's disease, dementia with Lewy bodies, and Alzheimer's disease.

    Science.gov (United States)

    Moreno-Ramos, Teresa; Benito-León, Julián; Villarejo, Alberto; Bermejo-Pareja, Félix

    2013-01-01

    Optical coherence tomography is a simple, high-resolution technique to quantify the thickness of retinal nerve fiber layer (RNFL). Previous studies have shown that degenerative changes occur in optic nerve fibers and are manifested as thinning of RNLF in patients with Alzheimer's disease (AD). However, there are no studies on the thickness of the RNLF in other types of dementia, such as dementia with Lewy bodies and dementia associated with Parkinson's disease. In this study, patients fulfilling diagnostic for AD (n = 10), dementia with Lewy bodies (n = 10), dementia associated with Parkinson's disease (n = 10), and cognitively normal age-matched controls (n = 10) underwent optical coherence tomography examinations to measure RNLF thickness. There was a significant decrease in RNLF thickness in each type of dementia compared to the control group (Mann-Whitney test, all p dementia with Lewy bodies may have a greater thinning than both patients with AD and dementia associated with Parkinson's disease, the differences were statistically nonsignificant (Kruskal-Wallis test, p = 0.525). The thickness of the RNLF correlated significantly (p Dementia Rating Scale scores in all types of dementia; that is to say, the greater the cognitive deterioration, the greater the reduction of thickness of the RNLF. The findings from this study show that retinal involvement measured by optical coherence tomography may also be present in non-AD dementias.

  13. Effect of Refractive Correction Error on Retinal Nerve Fiber Layer Thickness: A Spectralis Optical Coherence Tomography Study.

    Science.gov (United States)

    Ma, Xiaoli; Chen, Yutong; Liu, Xianjie; Ning, Hong

    2016-12-28

    BACKGROUND Identifying and assessing retinal nerve fiber layer defects are important for diagnosing and managing glaucoma. We aimed to investigate the effect of refractive correction error on retinal nerve fiber layer (RNFL) thickness measured with Spectralis spectral-domain optical coherence tomography (SD-OCT). MATERIAL AND METHODS We included 68 participants: 32 healthy (normal) and 36 glaucoma patients. RNFL thickness was measured using Spectralis SD-OCT circular scan. Measurements were made with a refractive correction of the spherical equivalent (SE), the SE+2.00D and the SE-2.00D. RESULTS Average RNFL thickness was significantly higher in the normal group (105.88±10.47 μm) than in the glaucoma group (67.67±17.27 μm, Pthickness. In the glaucoma group, +2.00D of refractive correction error significantly increased average (Pthickness measurements in either group. CONCLUSIONS Positive defocus error significantly affects RNFL thickness measurements made by the Spectralis SD-OCT. Negative defocus error did not affect RNFL measurement examined. Careful correction of refractive error is necessary to obtain accurate baseline and follow-up RNFL thickness measurements in healthy and glaucomatous eyes.

  14. Neuropeptide Y as a presynaptic modulator of norepinephrine release from the sympathetic nerve fibers in the pig pineal gland.

    Science.gov (United States)

    Ziółkowska, N; Lewczuk, B; Przybylska-Gornowicz, B

    2015-01-01

    Norepinephrine (NE) released from the sympathetic nerve endings is the main neurotransmitter controlling melatonin synthesis in the mammalian pineal gland. Although neuropeptide Y (NPY) co-exists with NE in the pineal sympathetic nerve fibers it also occurs in a population of non-adrenergic nerve fibers located in this gland. The role of NPY in pineal physiology is still enigmatic. The present study characterizes the effect of NPY on the depolarization-evoked 3H-NE release from the pig pineal explants. The explants of the pig pineal gland were loaded with 3H-NE in the presence of pargyline and superfused with Tyrode medium. They were exposed twice to the modified Tyrode medium containing 60 mM of K+ to evoke the 3H-NE release via depolarization. NPY, specific agonists of Y1- and Y2- receptors and pharmacologically active ligands of α2-adrenoceptors were added to the medium before and during the second depolarization. The radioactivity was measured in medium fractions collected every 2 minutes during the superfusion. NPY (0.1-10 μM) significantly decreased the depolarization-induced 3H-NE release. Similar effect was observed after the treatment with Y2-agonist: NPY13-36, but not with Y1-agonist: [Leu31,Pro34]-NPY. The tritium overflow was lower in the explants exposed to the 5 μM NPY and 1 μM rauwolscine than to rauwolscine only. The effects of 5 μM NPY and 0.05 μM UK 14,304 on the depolarization-evoked 3H-NE release were additive. The results show that NPY is involved in the regulation of NE release from the sympathetic terminals in the pig pineal gland, inhibiting this process via Y2-receptors.

  15. Persistent alterations in active and passive electrical membrane properties of regenerated nerve fibers of man and mice.

    Science.gov (United States)

    Moldovan, Mihai; Alvarez, Susana; Rosberg, Mette R; Krarup, Christian

    2016-02-01

    Excitability of regenerated fibers remains impaired due to changes in both passive cable properties and alterations in the voltage-dependent membrane function. These abnormalities were studied by mathematical modeling in human regenerated nerves and experimental studies in mice. In three adult male patients with surgically repaired complete injuries of peripheral nerves of the arm 22 months-26 years prior to investigation, deviation of excitability measures was explained by a hyperpolarizing shift in the resting membrane potential and an increase in the passive 'Barrett and Barrett' conductance (GBB) bridging the nodal and internodal compartments. These changes were associated with an increase in the 'fast' K(+) conductance and the inward rectifier conductance (GH). Similar changes were found in regenerated mouse tibial motor axons at 1 month after a sciatic crush lesion. During the first 5 months of regeneration, GH showed partial recovery, which paralleled that in GBB. The internodal length remained one-third of normal. Excitability abnormalities could be reversed by the energy-dependent Na(+)/K(+) pump blocker ouabain resulting in membrane depolarization. Stressing the Na(+) pumping system during a strenuous activity protocol triggered partial Wallerian degeneration in regenerated nerves but not in control nerves from age-matched mice. The current data suggest that the nodal voltage-gated ion channel machinery is restored in regenerated axons, although the electrical separation from the internodal compartment remains compromised. Due to the persistent increase in number of nodes, the increased activity-dependent Na(+) influx could lead to hyperactivity of the Na(+)/K(+) pump resulting in membrane hyperpolarization and neurotoxic energy insufficiency during strenuous activity. © 2015 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  16. Noise-induced hearing loss increases the temporal precision of complex envelope coding by auditory-nerve fibers

    Directory of Open Access Journals (Sweden)

    Kenneth Stuart Henry

    2014-02-01

    Full Text Available While changes in cochlear frequency tuning are thought to play an important role in the perceptual difficulties of people with sensorineural hearing loss (SNHL, the possible role of temporal processing deficits remains less clear. Our knowledge of temporal envelope coding in the impaired cochlea is limited to two studies that examined auditory-nerve fiber responses to narrowband amplitude modulated stimuli. In the present study, we used Wiener-kernel analyses of auditory-nerve fiber responses to broadband Gaussian noise in anesthetized chinchillas to quantify changes in temporal envelope coding with noise-induced SNHL. Temporal modulation transfer functions (TMTFs and temporal windows of sensitivity to acoustic stimulation were computed from 2nd-order Wiener kernels and analyzed to estimate the temporal precision, amplitude, and latency of envelope coding. Noise overexposure was associated with slower (less negative TMTF roll-off with increasing modulation frequency and reduced temporal window duration. The results show that at equal stimulus sensation level, SNHL increases the temporal precision of envelope coding by 20-30%. Furthermore, SNHL increased the amplitude of envelope coding by 50% in fibers with CFs from 1-2 kHz and decreased mean response latency by 0.4 ms. While a previous study of envelope coding demonstrated a similar increase in response amplitude, the present study is the first to show enhanced temporal precision. This new finding may relate to the use of a more complex stimulus with broad frequency bandwidth and a dynamic temporal envelope. Exaggerated neural coding of fast envelope modulations may contribute to perceptual difficulties in people with SNHL by acting as a distraction from more relevant acoustic cues, especially in fluctuating background noise. Finally, the results underscore the value of studying sensory systems with more natural, real-world stimuli.

  17. Automatic estimation of retinal nerve fiber bundle orientation in SD-OCT images using a structure-oriented smoothing filter

    Science.gov (United States)

    Ghafaryasl, Babak; Baart, Robert; de Boer, Johannes F.; Vermeer, Koenraad A.; van Vliet, Lucas J.

    2017-02-01

    Optical coherence tomography (OCT) yields high-resolution, three-dimensional images of the retina. A better understanding of retinal nerve fiber bundle (RNFB) trajectories in combination with visual field data may be used for future diagnosis and monitoring of glaucoma. However, manual tracing of these bundles is a tedious task. In this work, we present an automatic technique to estimate the orientation of RNFBs from volumetric OCT scans. Our method consists of several steps, starting from automatic segmentation of the RNFL. Then, a stack of en face images around the posterior nerve fiber layer interface was extracted. The image showing the best visibility of RNFB trajectories was selected for further processing. After denoising the selected en face image, a semblance structure-oriented filter was applied to probe the strength of local linear structure in a discrete set of orientations creating an orientation space. Gaussian filtering along the orientation axis in this space is used to find the dominant orientation. Next, a confidence map was created to supplement the estimated orientation. This confidence map was used as pixel weight in normalized convolution to regularize the semblance filter response after which a new orientation estimate can be obtained. Finally, after several iterations an orientation field corresponding to the strongest local orientation was obtained. The RNFB orientations of six macular scans from three subjects were estimated. For all scans, visual inspection shows a good agreement between the estimated orientation fields and the RNFB trajectories in the en face images. Additionally, a good correlation between the orientation fields of two scans of the same subject was observed. Our method was also applied to a larger field of view around the macula. Manual tracing of the RNFB trajectories shows a good agreement with the automatically obtained streamlines obtained by fiber tracking.

  18. Spectral domain optical coherence tomography in glaucoma: qualitative and quantitative analysis of the optic nerve head and retinal nerve fiber layer (an AOS thesis).

    Science.gov (United States)

    Chen, Teresa C

    2009-12-01

    To demonstrate that video-rate spectral domain optical coherence tomography (SDOCT) can qualitatively and quantitatively evaluate optic nerve head (ONH) and retinal nerve fiber layer (RNFL) glaucomatous structural changes. To correlate quantitative SDOCT parameters with disc photography and visual fields. SDOCT images from 4 glaucoma eyes (4 patients) with varying stages of open-angle glaucoma (ie, early, moderate, late) were qualitatively contrasted with 2 age-matched normal eyes (2 patients). Of 61 other consecutive patients recruited in an institutional setting, 53 eyes (33 patients) met inclusion/exclusion criteria for quantitative studies. Images were obtained using two experimental SDOCT systems, one utilizing a superluminescent diode and the other a titanium:sapphire laser source, with axial resolutions of about 6 microm and 3 microm, respectively. Classic glaucomatous ONH and RNFL structural changes were seen in SDOCT images. An SDOCT reference plane 139 microm above the retinal pigment epithelium yielded cup-disc ratios that best correlated with masked physician disc photography cup-disc ratio assessments. The minimum distance band, a novel SDOCT neuroretinal rim parameter, showed good correlation with physician cup-disc ratio assessments, visual field mean deviation, and pattern standard deviation (P values range, .0003-.024). RNFL and retinal thickness maps correlated well with disc photography and visual field testing. To our knowledge, this thesis presents the first comprehensive qualitative and quantitative evaluation of SDOCT images of the ONH and RNFL in glaucoma. This pilot study provides basis for developing more automated quantitative SDOCT-specific glaucoma algorithms needed for future prospective multicenter national trials.

  19. Optic Nerve Head and Retinal Nerve Fiber Layer Analysis in Ocular Hypertension and Early-Stage Glucoma Using Spectral-Domain Optical Coherence Tomography Copernicus

    Directory of Open Access Journals (Sweden)

    Nilgün Solmaz

    2014-01-01

    Full Text Available Objectives: Evaluation of structural alterations of the optic nerve head (ONH and the retinal nerve fiber layer (RNFL in patients with ocular hypertension (OHT and early-stage glaucoma and assessment of the discriminatory diagnostic performance of spectral-domain optical coherence tomography (SD-OCT Copernicus (Optopol Technology S.A.. Materials and Methods: This study included 59 eyes of a total of 59 patients, 29 of whom were diagnosed with OHT (Group 1 and 30 with early-stage glaucoma (Group 2. The differentiation of early-stage glaucoma and OHT was carried out on the basis of standard achromatic visual field test results. Analysis of the ONH and RNFL thickness of all cases was made using SD-OCT. Group 1 and Group 2 were compared with respect to the ONH parameters and RNFL thickness. The diagnostic sensitivity of the OCT parameters was evaluated by the area under the receiver operating characteristics curves (AUC. Results: The average, superior, inferior, and nasal RNFL thicknesses in early-stage glaucoma cases were approximately 10% (12-14 µm less compared to the OHT eyes, with differences being highly significant (p≤0.001. However, there was no statistically significant difference in the temporal RNFL thicknesses. The most sensitive parameter in the early diagnosis of glaucoma was average RNFL thickness corresponding to AUC: 0.852, followed by AUC: 0.816 and AUC: 0.773 values in superior and inferior RNFL thickness, respectively. In localized RNFL defects, the highest sensitivity corresponded to superior and superonasal quadrants (ACU: 0.805 and ACU: 0.781, respectively. There were not any statistically significant differences between the ONH morphological parameters of the two groups. Conclusion: RNFL analysis obtained using SD-OCT Copernicus is able to discriminate early-stage glaucoma eyes from those with OHT. However, ONH morphological parameters do not have the same diagnostic sensitivity. Turk J Ophthalmol 2014; 44: 35-41

  20. Spectral Domain Optical Coherence Tomography in Glaucoma: Qualitative and Quantitative Analysis of the Optic Nerve Head and Retinal Nerve Fiber Layer (An AOS Thesis)

    Science.gov (United States)

    Chen, Teresa C.

    2009-01-01

    Purpose: To demonstrate that video-rate spectral domain optical coherence tomography (SDOCT) can qualitatively and quantitatively evaluate optic nerve head (ONH) and retinal nerve fiber layer (RNFL) glaucomatous structural changes. To correlate quantitative SDOCT parameters with disc photography and visual fields. Methods: SDOCT images from 4 glaucoma eyes (4 patients) with varying stages of open-angle glaucoma (ie, early, moderate, late) were qualitatively contrasted with 2 age-matched normal eyes (2 patients). Of 61 other consecutive patients recruited in an institutional setting, 53 eyes (33 patients) met inclusion/exclusion criteria for quantitative studies. Images were obtained using two experimental SDOCT systems, one utilizing a superluminescent diode and the other a titanium:sapphire laser source, with axial resolutions of about 6 μm and 3 μm, respectively. Results: Classic glaucomatous ONH and RNFL structural changes were seen in SDOCT images. An SDOCT reference plane 139 μm above the retinal pigment epithelium yielded cup-disc ratios that best correlated with masked physician disc photography cup-disc ratio assessments. The minimum distance band, a novel SDOCT neuroretinal rim parameter, showed good correlation with physician cup-disc ratio assessments, visual field mean deviation, and pattern standard deviation (P values range, .0003–.024). RNFL and retinal thickness maps correlated well with disc photography and visual field testing. Conclusions: To our knowledge, this thesis presents the first comprehensive qualitative and quantitative evaluation of SDOCT images of the ONH and RNFL in glaucoma. This pilot study provides basis for developing more automated quantitative SDOCT-specific glaucoma algorithms needed for future prospective multicenter national trials. PMID:20126502

  1. Interocular symmetry of retinal nerve fiber layer and optic nerve head parameters measured by Cirrus high-definition optical coherence tomography in a normal pediatric population.

    Science.gov (United States)

    Pawar, Neelam; Maheshwari, Devendra; Ravindran, Meenakshi; Ramakrishnan, Renagappa

    2017-10-01

    To determine interocular differences in the retinal nerve fiber layer (RNFL) and optic nerve head (ONH) parameters in a pediatric population using Cirrus high-definition optical coherence tomography (HD-OCT). Seventy normal Indian children aged 5-17 years presenting to the Pediatric Clinic were included in this observational cross-sectional study. All subjects underwent a comprehensive ophthalmologic examination and an evaluation of the RNFL and ONH by Cirrus HD-OCT. Differences between the right and left eyes were calculated and values were compared by means of a paired t-test. Subjects were also divided into two groups based on age (under or over 10 years of age). Interocular differences in RNFL and ONH parameters together with sex and age variations for these differences were determined. The mean age of studied pediatric population was 11.83 ± 3.3 years (range 5-17). Average RNFL thickness was 94.46 ± 8.7 μm (± SD) (range 77-111). Differences in the average RNFL between right and left eyes were not statistically significant (P = 0.060). Superior quadrant RNFL was thicker in the left eye and temporal quadrant was thicker in the right eye. Among ONH parameters, there were no statistically significant differences in any parameters, except vertical cup-disc (CD) ratio which was significant (P = 0.007). The 2.5%-97.5% limits of asymmetry were 9 μm for average RNFL, 0.14 for average CD ratio, and 0.22 for vertical CD ratio. Mean interocular RNFL thickness differences in superior, superior nasal, and temporal superior quadrants were 10.61 (P population. The normal interocular RNFL asymmetry should not exceed 9 μm and vertical CD ratio beyond 0.22 should be considered for further investigations. The physiologic asymmetry provided by this study may assist in identifying changes in RNFL thickness and ONH parameters in pediatric glaucoma and ONH disorders.

  2. Peripheral nerves are pathologically small in Cerebellar Ataxia Neuropathy Vestibular Areflexia Syndrome (CANVAS): A controlled ultrasound study.

    Science.gov (United States)

    Pelosi, Luciana; Mulroy, Eoin; Leadbetter, Ruth; Kilfoyle, Dean; Chancellor, Andrew M; Mossman, Stuart; Wing, Laurie; Wu, Teddy Y; Roxburgh, Richard H

    2018-01-05

    Sensory neuronopathy is a cardinal feature of Cerebellar Ataxia Neuropathy Vestibular Areflexia Syndrome (CANVAS). Having observed that two patients with CANVAS had small median and ulnar nerves on ultrasound, we set out to examine this finding systematically in a cohort of patients with CANVAS, and compare them with both healthy controls and a cohort of patients with axonal neuropathy. We have previously reported preliminary findings in seven of these CANVAS patients and seven healthy controls. We compared the ultrasound cross-sectional area of median, ulnar, sural and tibial nerves of 14 CANVAS patients with 14 healthy controls and 14 age-and-gender matched patients with acquired primarily axonal neuropathy. We also compared the individual nerve cross-sectional areas of CANVAS and neuropathy patients with the reference values of our laboratory control population. The nerve cross-sectional area of CANVAS patients was smaller than that of both the healthy controls and the neuropathy controls, with highly significant differences at most sites (p<0.001). Conversely, the nerve cross-sectional areas in the upper limb were larger amongst neuropathy controls than healthy controls (p<0.05). On individual analysis, the ultrasound abnormality was sufficiently characteristic to be detected in all but one CANVAS patient. Small nerves in CANVAS probably reflect nerve thinning from loss of axons due to ganglion cell loss. This is distinct from the ultrasound findings in axonal neuropathy, in which nerve size was either normal or enlarged. Our findings indicate a diagnostic role for ultrasound in CANVAS sensory neuronopathy and in differentiating neuronopathy from neuropathy. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  3. The Effect of Electrospun Gelatin Fibers Alignment on Schwann Cell and Axon Behavior and Organization in the Perspective of Artificial Nerve Design

    Directory of Open Access Journals (Sweden)

    Sara Gnavi

    2015-06-01

    Full Text Available Electrospun fibrous substrates mimicking extracellular matrices can be prepared by electrospinning, yielding aligned fibrous matrices as internal fillers to manufacture artificial nerves. Gelatin aligned nano-fibers were prepared by electrospinning after tuning the collector rotation speed. The effect of alignment on cell adhesion and proliferation was tested in vitro using primary cultures, the Schwann cell line, RT4-D6P2T, and the sensory neuron-like cell line, 50B11. Cell adhesion and proliferation were assessed by quantifying at several time-points. Aligned nano-fibers reduced adhesion and proliferation rate compared with random fibers. Schwann cell morphology and organization were investigated by immunostaining of the cytoskeleton. Cells were elongated with their longitudinal body parallel to the aligned fibers. B5011 neuron-like cells were aligned and had parallel axon growth when cultured on the aligned gelatin fibers. The data show that the alignment of electrospun gelatin fibers can modulate Schwann cells and axon organization in vitro, suggesting that this substrate shows promise as an internal filler for the design of artificial nerves for peripheral nerve reconstruction.

  4. The Effect of Electrospun Gelatin Fibers Alignment on Schwann Cell and Axon Behavior and Organization in the Perspective of Artificial Nerve Design.

    Science.gov (United States)

    Gnavi, Sara; Fornasari, Benedetta Elena; Tonda-Turo, Chiara; Laurano, Rossella; Zanetti, Marco; Ciardelli, Gianluca; Geuna, Stefano

    2015-06-08

    Electrospun fibrous substrates mimicking extracellular matrices can be prepared by electrospinning, yielding aligned fibrous matrices as internal fillers to manufacture artificial nerves. Gelatin aligned nano-fibers were prepared by electrospinning after tuning the collector rotation speed. The effect of alignment on cell adhesion and proliferation was tested in vitro using primary cultures, the Schwann cell line, RT4-D6P2T, and the sensory neuron-like cell line, 50B11. Cell adhesion and proliferation were assessed by quantifying at several time-points. Aligned nano-fibers reduced adhesion and proliferation rate compared with random fibers. Schwann cell morphology and organization were investigated by immunostaining of the cytoskeleton. Cells were elongated with their longitudinal body parallel to the aligned fibers. B5011 neuron-like cells were aligned and had parallel axon growth when cultured on the aligned gelatin fibers. The data show that the alignment of electrospun gelatin fibers can modulate Schwann cells and axon organization in vitro, suggesting that this substrate shows promise as an internal filler for the design of artificial nerves for peripheral nerve reconstruction.

  5. Neuroanatomical Relationships between Orexin/Hypocretin-Containing Neurons/Nerve Fibers and Nicotine-Induced c-Fos-Activated Cells of the Reward-Addiction Neurocircuitry

    Science.gov (United States)

    Dehkordi, Ozra; Rose, Jed E; Dávila-García, Martha I; Millis, Richard M; Mirzaei, Samar Ali; Manaye, Kebreten F; Jayam-Trouth, Annapurni

    2017-01-01

    Orexin/hypocretin-containing neurons in lateral hypothalamus (LH) are implicated in the neurobiology of nicotine addiction. However, the neuroanatomical relationships between orexin-neurons/nerve fibers and nicotine-activated cells within the reward-addiction neurocircuitry is not known. In the present study in mice, we first used c-Fos immunohistochemistry to identify CNS cells stimulated by an acute single injection of nicotine (NIC, 2 mg/kg, IP). Sequential double-labelling was then performed to identify the location of orexin-containing neurons and nerve fibers with respect to NIC-induced c-Fos activated cells and/or tyrosine hydroxylase (TH) immunoreactive (IR) cells of the mesocorticolimbic reward-addiction pathways. Orexin-IR nerve fibers and terminals were detected at multiple sites of the NIC reward-addiction circuitry in close apposition to, and intermingled with, NIC-induced c-Fos-IR cells of locus coeruleus (LC), ventral tegmental area (VTA), nucleus accumbens (Acb), LH and paraventricular thalamic nucleus (PVT). Double-labelling of orexin with TH showed frequent contact between orexin-IR nerve fibers and noradrenergic cells of LC. However, there was infrequent contact between the orexinergic fibers and the TH-expressing dopaminergic cells of VTA, dorsal raphe nucleus (DR), posterior hypothalamus (DA11), arcuate hypothalamic nucleus (DA12) and periventricular areas (DA14). The close anatomical contact between orexinergic nerve fibers and NIC-activated cells at multiple sites of the reward-addiction pathways suggests that orexinergic projections from LH are likely to be involved in modulating activity of the neurons that are directly impacted by acute administration of nicotine. PMID:29038792

  6. Optical coherence tomography, scanning laser polarimetry and confocal scanning laser ophthalmoscopy in retinal nerve fiber layer measurements of glaucoma patients.

    Science.gov (United States)

    Fanihagh, Farsad; Kremmer, Stephan; Anastassiou, Gerasimos; Schallenberg, Maurice

    2015-01-01

    To determine the correlations and strength of association between different imaging systems in analyzing the retinal nerve fiber layer (RNFL) of glaucoma patients: optical coherence tomography (OCT), scanning laser polarimetry (SLP) and confocal scanning laser ophthalmoscopy (CSLO). 114 eyes of patients with moderate open angle glaucoma underwent spectral domain OCT (Topcon SD-OCT 2000 and Zeiss Cirrus HD-OCT), SLP (GDx VCC and GDx Pro) and CSLO (Heidelberg Retina Tomograph, HRT 3). Correlation coefficients were calculated between the structural parameters yielded by these examinations. The quantitative relationship between the measured RNFL thickness globally and for the four regions (superior, inferior, nasal, temporal) were evaluated with different regression models for all used imaging systems. The strongest correlation of RNFL measurements was found between devices using the same technology like GDx VCC and GDx Pro as well as Topcon OCT and Cirrus OCT. In glaucoma patients, the strongest associations (R²) were found between RNFL measurements of the two optical coherence tomography devices Topcon OCT and Cirrus OCT (R² = 0.513) and between GDx VCC and GDx Pro (R² = 0.451). The results of the OCTs and GDX Pro also had a strong quantitative relationship (Topcon OCT R² = 0.339 and Cirrus OCT R² = 0.347). GDx VCC and the OCTs showed a mild to moderate association (Topcon OCT R² = 0.207 and Cirrus OCT R² = 0.258). The confocal scanning laser ophthalmoscopy (HRT 3) had the lowest association to all other devices (Topcon OCT R² = 0.254, Cirrus OCT R² = 0.158, GDx Pro R² = 0.086 and GDx VCC R² = 0.1). The measurements of the RNFL in glaucoma patients reveal a high correlation of OCT and GDx devices because OCTs can measure all major retinal layers and SLP can detect nerve fibers allowing a comparison between the results of this devices. However, CSLO by means of HRT topography can only measure height values of the retinal surface but it cannot distinguish

  7. Spatiotemporal dynamics of re-innervation and hyperinnervation patterns by uninjured CGRP fibers in the rat foot sole epidermis after nerve injury

    Directory of Open Access Journals (Sweden)

    Duraku Liron S

    2012-08-01

    Full Text Available Abstract The epidermis is innervated by fine nerve endings that are important in mediating nociceptive stimuli. However, their precise role in neuropathic pain is still controversial. Here, we have studied the role of epidermal peptidergic nociceptive fibers that are located adjacent to injured fibers in a rat model of neuropathic pain. Using the Spared Nerve Injury (SNI model, which involves complete transections of the tibial and common peroneal nerve while sparing the sural and saphenous branches, mechanical hypersensitivity was induced of the uninjured lateral (sural and medial (saphenous area of the foot sole. At different time points, a complete foot sole biopsy was taken from the injured paw and processed for Calcitonin Gene-Related Peptide (CGRP immunohistochemistry. Subsequently, a novel 2D-reconstruction model depicting the density of CGRP fibers was made to evaluate the course of denervation and re-innervation by uninjured CGRP fibers. The results show an increased density of uninjured CGRP-IR epidermal fibers on the lateral and medial side after a SNI procedure at 5 and 10 weeks. Furthermore, although in control animals the density of epidermal CGRP-IR fibers in the footpads was lower compared to the surrounding skin of the foot, 10 weeks after the SNI procedure, the initially denervated footpads displayed a hyper-innervation. These data support the idea that uninjured fibers may play a considerable role in development and maintenance of neuropathic pain and that it is important to take larger biopsies to test the relationship between innervation of injured and uninjured nerve areas.

  8. Wiener kernels of chinchilla auditory-nerve fibers : Verification using responses to tones, clicks, and noise and comparison with basilar-membrane vibrations

    NARCIS (Netherlands)

    Temchin, AN; Recio-Spinoso, A; van Dijk, P; Ruggero, MA

    Responses to tones, clicks, and noise were recorded from chinchilla auditory-nerve fibers (ANFs). The responses to noise were analyzed by computing the zeroth-, first-, and second-order Wiener kernels (h(0), h(1), and h(2)). The h(1) s correctly predicted the frequency tuning and phases of responses

  9. Association of Maternal Smoking During Pregnancy and Birth Weight With Retinal Nerve Fiber Layer Thickness in Children Aged 11 or 12 Years

    DEFF Research Database (Denmark)

    Ashina, Håkan; Li, Xiao Qiang; Olsen, Else Marie

    2017-01-01

    Importance: Both maternal smoking during pregnancy and low birth weight have been implicated in impaired development of the retina. Objective: To investigate the associations of maternal smoking during pregnancy and low birth weight with retinal nerve fiber layer (RNFL) thickness in preadolescent...

  10. Skeletal muscle fiber, nerve, and blood vessel breakdown in space-flown rats

    Science.gov (United States)

    Riley, D. A.; Ilyina-Kakueva, E. I.; Ellis, S.; Bain, J. L.; Slocum, G. R.; Sedlak, F. R.

    1990-01-01

    Histochemical and ultrastructural analyses were performed postflight on hind limb skeletal muscles of rats orbited for 12.5 days aboard the unmanned Cosmos 1887 biosatellite and returned to Earth 2 days before sacrifice. The antigravity adductor longus (AL), soleus, and plantaris muscles atrophied more than the non-weight-bearing extensor digitorum longus, and slow muscle fibers were more atrophic than fast fibers. Muscle fiber segmental necrosis occurred selectively in the AL and soleus muscles; primarily, macrophages and neutrophils infiltrated and phagocytosed cellular debris. Granule-rich mast cells were diminished in flight AL muscles compared with controls, indicating the mast cell secretion contributed to interstitial tissue edema. Increased ubiquitination of disrupted myofibrils implicated ubiquitin in myofilament degradation. Mitochondrial content and succinic dehydrogenase activity were normal, except for subsarcolemmal decreases. Myofibrillar ATPase activity of flight AL muscle fibers shifted toward the fast type. Absence of capillaries and extravasation of red blood cells indicated failed microcirculation. Muscle fiber regeneration from activated satellite cells was detected. About 17% of the flight AL end plates exhibited total or partial denervation. Thus, skeletal muscle weakness associated with spaceflight can result from muscle fiber atrophy and segmental necrosis, partial motor denervation, and disruption of the microcirculation.

  11. Comparison of Central Corneal Thickness and Retinal Nerve Fiber Layer Thickness and Ganglion Cell Complex in Patients with Ocular Hypertension

    Directory of Open Access Journals (Sweden)

    Gamze Mumcu Taşlı

    2013-12-01

    Full Text Available Purpose: To evaluate the correlation of retinal nerve fiber layer thickness (RNFLT with ganglion cell complex and central corneal thickness (CCT measurements in patients with ocular hypertension and healthy subjects. Material and Method: Seventy-six eyes of 38 patients with ocular hypertension and 76 eyes of 38 healthy subjects were included in this study. Both groups were stratified by CCT into 579 µm (p0.05. In the control group, there was no significant correlation between CCT and RNFLT (average, superior average, inferior average measurements (p>0.05. There was no significant correlation between CCT and average, superior average, inferior average ganglion cell complex in both groups. Discussion: Ocular hypertension patients with CCT <550 µm may represent patients who have very early undetected glaucoma. This may in part explain the higher risk of these patients for progression to glaucoma. (Turk J Ophthalmol 2013; 43: 385-90

  12. Structural Measurements for Monitoring Change in Glaucoma: Comparing Retinal Nerve Fiber Layer Thickness With Minimum Rim Width and Area.

    Science.gov (United States)

    Gardiner, Stuart K; Boey, Pui Yi; Yang, Hongli; Fortune, Brad; Burgoyne, Claude F; Demirel, Shaban

    2015-10-01

    Minimum rim width (MRW) and area (MRA) have been introduced as anatomically defensible measures of neuroretinal rim tissue observable using spectral-domain optical coherence tomography (SDOCT). They have been reported to change earlier than retinal nerve fiber layer thickness (RNFLT) in glaucoma. This study sought to determine which is better to distinguish subsequent change from variability, using the previously described longitudinal signal-to-noise ratio (LSNR). Data from 157 eyes of 157 participants with high-risk ocular hypertension or non-end-stage glaucoma (mean deviation [MD] from -22 to +3 dB) were used. Participants were tested approximately every 6 months for at least six visits. For each eye, MRW, MRA, and RNFLT were regressed linearly against time. Longitudinal signal-to-noise ratio for each eye was defined as the rate of change over time (signal) divided by the standard deviation of residuals from this trend (noise). These were compared between parameters using a Wilcoxon signed rank test. The median LSNRs were -0.58y⁻¹ for RNFLT (bootstrapped 95% confidence interval -0.69 to -0.48y⁻¹); -0.44y⁻¹ (-0.59 to -0.32y⁻¹) for MRW; and -0.23y⁻¹ (-0.32 to -0.08y⁻¹) for MRA. Longitudinal signal-to-noise ratios were significantly more negative for RNFLT than for MRW (P = 0.025) or for MRA (P < 0.001). Retinal nerve fiber layer thickness measured by SDOCT had a better LSNR than MRW or MRA. Although MRW and MRA may be more sensitive for early detection of glaucomatous damage, these data suggest that RNFLT may be preferable for monitoring change.

  13. Effect of cataract surgery on retinal nerve fiber layer thickness parameters using scanning laser polarimetry (GDxVCC).

    Science.gov (United States)

    Dada, Tanuj; Behera, Geeta; Agarwal, Anand; Kumar, Sanjeev; Sihota, Ramanjit; Panda, Anita

    2010-01-01

    To study the effect of cataract extraction on the retinal nerve fiber layer (RNFL) thickness, and assessment by scanning laser polarimetry (SLP), with variable corneal compensation (GDx VCC), at the glaucoma service of a tertiary care center in North India. Thirty-two eyes of 32 subjects were enrolled in the study. The subjects underwent RNFL analysis by SLP (GDx VCC) before undergoing phacoemulsification cataract extraction with intraocular lens (IOL) implantation (Acrysof SA 60 AT) four weeks following cataract surgery. The RNFL thickness parameters evaluated both before and after surgery included temporal, superior, nasal, inferior, temporal (TSNIT) average, superior average, inferior average, and nerve fiber index (NFI). The mean age of subjects was 57.6 +/- 11.7 years (18 males, 14 females). Mean TSNIT average thickness (microm) pre- and post-cataract surgery was 49.2 +/- 14.1 and 56.5 +/- 7.6 ( P = 0.001). There was a statistically significant increase in RNFL thickness parameters (TSNIT average, superior average, and inferior average) and decrease in NFI post-cataract surgery as compared to the baseline values. Mean NFI pre- and post-cataract surgery was 41.3 +/- 15.3 and 21.6 +/- 11.8 ( P = 0.001). Measurement of RNFL thickness parameters by scanning laser polarimetry is significantly altered following cataract surgery. Post the cataract surgery, a new baseline needs to be established for assessing the longitudinal follow-up of a glaucoma patient. The presence of cataract may lead to an underestimation of the RNFL thickness, and this should be taken into account when analyzing progression in a glaucoma patient.

  14. Effect of motion artifacts and scan circle displacements on Cirrus HD-OCT retinal nerve fiber layer thickness measurements.

    Science.gov (United States)

    Taibbi, Giovanni; Peterson, Gregory C; Syed, Misha F; Vizzeri, Gianmarco

    2014-04-07

    To evaluate the effect of scan circle displacements on retinal nerve fiber layer thickness (RNFLT) measurements in Cirrus HD-OCT scans with motion artifacts affecting the optic disc. In this cross-sectional study, 70 scans from 18 healthy eyes and 100 scans from 26 glaucomatous eyes were divided into 85 pairs, each composed by a scan with one motion artifact affecting the optic disc, and a scan from the same eye without motion artifacts. En face images underwent automated realignment, and horizontal/vertical scan circle displacements were determined. Multiple regression analysis evaluated the relationship between scan circle displacements and RNFLT change. Scans with motion artifacts showed similar displacements in healthy and glaucomatous eyes (P values ≥ 0.08). Average RNFLT and quadrants were relatively unchanged, while clock-hours showed more changes (e.g., in glaucomatous eyes, clock-hour-7 RNFLT was lower in scans with motion artifacts, P = 0.05). Scan circle displacements produced average RNFLT changes above test-retest variability in 3/85 cases (3.53%). Retinal nerve fiber layer thickness tended to decrease in sectors moved away from the disc and to increase in sectors closer to the disc (R(2) ≤ 0.40 and R(2) ≤ 0.22 in healthy and glaucomatous eyes, respectively). In healthy eyes, horizontal displacements ≥ 423 and 325 μm were associated with average and quadrant RNFLT changes above test-retest variability, respectively. Scan circle displacements occurred in all scans with motions artifacts affecting the optic disc. Average RNFLT and quadrants were more robust than clock-hours. Because motion artifacts may be difficult to detect, clinicians should carefully inspect en face OCT images for their presence and interpret clock-hour results cautiously.

  15. Changes in retinal nerve fiber layer and optic disc algorithms by optical coherence tomography in glaucomatous Arab subjects

    Directory of Open Access Journals (Sweden)

    Zeried FM

    2013-09-01

    Full Text Available Ferial M Zeried, Uchechukwu L Osuagwu Department of Optometry and Vision Sciences College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia Purpose: To assess the difference in retinal nerve fiber layer (RNFL and optic disc algorithms between glaucomatous and normal Arab subjects using optical coherence tomography (OCT. Methods: RNFL thickness and optic disc parameters were obtained in 65 patients aged 50.1 ± 7.7 years. Percentage differences in all parameters were calculated and analyzed between groups. Results: The mean RNFL thickness around the disc and at all quadrants was significantly thinner in glaucomatous eyes than in normal eyes (P < 0.01. The greatest decrease in RNFL thickness was observed at the inferior (39.5% and superior (39.3% quadrants and at 1 o’clock (43% and 5 o’clock (40% hour sectors. Significant differences were observed between glaucomatous and control eyes in all disc parameters (P < 0.005 assessed. The disc area, cup area, mean cup/disc ratio, and vertical and horizontal cup/disc ratios were significantly larger (P < 0.01, whereas the vertical integrated rim area, horizontal integrated rim width, and rim area were significantly smaller (P < 0.001 in glaucomatous eyes than in normal eyes. Conclusion: Stratus OCT is still a valuable tool in the diagnosis of early glaucoma changes and, as such, its use should be encouraged in glaucoma clinics in Saudi Arabia. The best OCT parameters for detecting early glaucoma change were RNFL thickness in the inferior, superior, and 1 o’clock hour sector; the cup area; and the vertical integrated rim area of the optic disc. Keywords: glaucoma, Stratus optical coherence tomography, optic disc, retinal nerve fiber layer (RNFL, age, Saudi Arabia

  16. Thinner Retinal Nerve Fiber Layer in Very Preterm Versus Term Infants and Relationship to Brain Anatomy and Neurodevelopment.

    Science.gov (United States)

    Rothman, Adam L; Sevilla, Monica B; Mangalesh, Shwetha; Gustafson, Kathryn E; Edwards, Laura; Cotten, C Michael; Shimony, Joshua S; Pizoli, Carolyn E; El-Dairi, Mays A; Freedman, Sharon F; Toth, Cynthia A

    2015-12-01

    To assess retinal nerve fiber layer (RNFL) thickness at term-equivalent age in very preterm (compare very preterm infant RNFL thickness with brain anatomy and neurodevelopment. Cohort study. RNFL was semi-automatically segmented (1 eye per infant) in 57 very preterm and 50 term infants with adequate images from bedside portable, handheld spectral-domain optical coherence tomography imaging at 37-42 weeks postmenstrual age. Mean RNFL thickness was calculated for the papillomacular bundle (-15 degrees to +15 degrees) and temporal quadrant (-45 degrees to +45 degrees) relative to the fovea-optic nerve axis. Brain magnetic resonance imaging (MRI) scans clinically obtained in 26 very preterm infants were scored for global structural abnormalities by an expert masked to data except for age. Cognitive, language, and motor skills were assessed in 33 of the very preterm infants at 18-24 months corrected age. RNFL was thinner for very preterm vs term infants at the papillomacular bundle ([mean ± standard deviation] 61 ± 17 vs 72 ± 13 μm, P brain MRI lesion burden index (R(2) = 0.35, P = .001) and lower cognitive (R(2) = 0.18, P = .01) and motor (R(2) = 0.17, P = .02) scores. Relationships were similar for temporal quadrant. Thinner RNFL in very preterm infants relative to term-born infants may relate to brain structure and neurodevelopment. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. A reappraisal of small- and large-fiber damage in carpal tunnel syndrome: New insights into the value of the EMLA test for improving diagnostic sensitivity.

    Science.gov (United States)

    Triki, Leila; Zouari, Hela G; Kammoun, Rim; Kammoun, Firas; Kammoun, Ines; Masmoudi, Kaouthar; Lefaucheur, Jean-Pascal

    2017-12-01

    To reappraise the respective involvement of small- and large-fiber damage in carpal tunnel syndrome (CTS) and to determine the diagnostic sensitivity of autonomic tests compared to conventional nerve conduction study (NCS). Thirty-two manual workers complaining of at least unilateral CTS were enrolled. They underwent clinical interview and completed the symptom severity scale of the Boston CTS Questionnaire (sssBCTQ) and the Neuropathic Pain Symptom Inventory (NPSI). In addition, transcarpal NCS was performed to investigate large sensory and motor fibers of the median nerve, while small autonomic fibers were assessed by recording sympathetic skin reflexes (SSR) at the palm and by grading skin wrinkling in response to eutectic mixture of local anesthetic (EMLA) cream application at the pulp of the index finger. For each neurophysiological variable, sensitivity and specificity values for the diagnosis of CTS were calculated and clinical correlations were studied. Among 64 hands examined, 36 were clinically symptomatic, while 22 were clinically asymptomatic and served as controls. Among all the neurophysiological variables studied, only the values of transcarpal sensory nerve conduction velocity and the EMLA test grade were found to be more altered in clinically symptomatic hands, with also a trend towards prolonged distal motor latency. Overall, for the diagnosis of clinically symptomatic CTS, NCS, SSR, and the EMLA test had a sensitivity of 66.7%, 22.2%, and 69.4%, respectively, and a specificity of 72.7%, 90.9%, and 50%, respectively. Combining NCS and the EMLA test led to a sensitivity of 88.9% and a specificity of 45.4%. The sssBCTQ (r=-0.34, P=0.009) and the total NPSI score (r=-0.41, P=0.001) correlated to a more altered EMLA test grade, but not to any NCS or SSR variables. In symptomatic hands, burning sensation was associated with more severe small-fiber lesion, while other pain and sensory symptoms were rather found to be reduced in case of large-fiber

  18. Central projections of the vestibular nerve: a review and single fiber study in the Mongolian gerbil.

    Science.gov (United States)

    Newlands, Shawn D; Perachio, Adrian A

    2003-06-15

    The primary purpose of this article is to review the anatomy of central projections of the vestibular nerve in amniotes. We also report primary data regarding the central projections of individual horseradish peroxidase (HRP)-filled afferents innervating the saccular macula, horizontal semicircular canal ampulla, and anterior semicircular canal ampulla of the gerbil. In total, 52 characterized primary vestibular afferent axons were intraaxonally injected with HRP and traced centrally to terminations. Lateral and anterior canal afferents projected most heavily to the medial and superior vestibular nuclei. Saccular afferents projected strongly to the spinal vestibular nucleus, weakly to other vestibular nuclei, to the interstitial nucleus of the eighth nerve, the cochlear nuclei, the external cuneate nucleus, and nucleus y. The current findings reinforce the preponderance of literature. The central distribution of vestibular afferents is not homogeneous. We review the distribution of primary afferent terminations described for a variety of mammalian and avian species. The tremendous overlap of the distributions of terminals from the specific vestibular nerve branches with one another and with other sensory inputs provides a rich environment for sensory integration.

  19. Fiber types in the striated urethral and anal sphincters

    DEFF Research Database (Denmark)

    Schrøder, H D; Reske-Nielsen, E

    1983-01-01

    connective tissue, and numerous intramuscular nerves are seen. No spindles are observed. The muscle fibers, particularly the predominant type 1 fibers are very small (about 15 micron in diameter). The fiber characteristics of the sphincters indicate that these muscles have a capacity to produce sustained...

  20. Relation Between the Frequency of Short-Pulse Electrical Stimulation of Afferent Nerve Fibers and Evoked Muscle Force.

    Science.gov (United States)

    Dideriksen, Jakob; Leerskov, Kasper; Czyzewska, Magdalena; Rasmussen, Rune

    Objective: Functional electrical stimulation (FES) is conventionally performed by the stimulation of motor axons causing the muscle fibers innervated by these axons to contract. An alternative strategy that may evoke contractions with more natural motor unit behavior is to stimulate afferent fibers (primarily type Ia) to excite the motor neurons at the spinal level. The aim of the study was to investigate the range of forces that can be evoked in this way and the degree to which the torque can be controlled. Methods: We stimulated the tibial nerve of ten healthy participants at amplitudes at which the highest H-reflex with minimal M-wave was present. The evoked plantar flexion torque was recorded following short stimulation pulses (0.4 ms) with frequencies ranging from 20 to 200 Hz. Results: Across all subjects, the median highest evocable torque was 38.3% (quartiles: 16.9-51.0) of the maximum voluntary contraction torque (MVC). The average torque variability (standard deviation) was 1.7 +/- 0.7% MVC. For most subjects, the relation between stimulation frequency and evoked torque was well characterized by sigmoidal curves (median root mean square error: 6.4% MVC). The plateau of this sigmoid curve (indicating the range of frequencies over which torque amplitude could be modulated) was reached at 56.0 (quartiles: 29.4-81.9) Hz. Conclusion: Using the proposed method for FES, substantial evoked torques that could be controlled by stimulation frequency were achieved. Significance: Stimulation of afferent fibers could be a useful and fatigue-resistant strategy for several applications of FES.Objective: Functional electrical stimulation (FES) is conventionally performed by the stimulation of motor axons causing the muscle fibers innervated by these axons to contract. An alternative strategy that may evoke contractions with more natural motor unit behavior is to stimulate afferent fibers (primarily type Ia) to excite the motor neurons at the spinal level. The aim of the

  1. Damage detection of satellite structures by optical fiber with small diameter

    Science.gov (United States)

    Kabashima, Shigenori; Ozaki, Tsuyoshi; Takeda, Nobuo

    2000-06-01

    Although there have been many researches concerning health monitoring system in the aerospace field, most of such researches relate to aircraft; there are only few that relate to satellite structures. This research first points out merit of the health monitoring system. The health monitoring system usually utilizes optical fiber sensor of which the diameter is 125 micrometer. However, such fiber sensors tend to be perceived as obstacles within the structure, which affects the soundness of the structure. This is especially the case in satellite structure, which utilizes especially thin composite laminates. In view of this problem, this study utilizes small diameter optical fiber, which is less likely to affect the soundness of the structure. The optical fiber is 40 micrometer in cladding diameter, and is embedded in the composite laminate structure. The structure and the optical fiber have been visually observed. Also, tensile test has been conducted on the structure. The result of the study indicates that the small diameter optical fiber can be embedded in the structure without affecting the soundness of the structure. The study further found that compressive destruction of a face sheet of a honeycomb sandwich panel having thin face sheets can be detected by utilizing this optical fiber.

  2. Functional and structural nerve fiber findings in heterozygote patients with Fabry disease

    DEFF Research Database (Denmark)

    Torvin, Moller A.; Winther, Bach F.; Feldt-Rasmussen, U.

    2009-01-01

    recently disease manifestations in female carriers of Fabry disease have been questioned. To explore the frequency of symptoms and the functional and structural involvement of the nervous system in female patients we examined the presence of pain, manifestations of peripheral neuropathy and nerve density......Fabry disease is an X-linked inherited lysosomal disorder with dysfunction of the lysosomal enzyme alpha-galactosidase A causing accumulation of glycolipids in multiple organs including the nervous system. Pain and somatosensory disturbances are prominent manifestations of this disease. Until...

  3. The robustness of speech representations obtained from simulated auditory nerve fibers under different noise conditions.

    Science.gov (United States)

    Jürgens, Tim; Brand, Thomas; Clark, Nicholas R; Meddis, Ray; Brown, Guy J

    2013-09-01

    Different methods of extracting speech features from an auditory model were systematically investigated in terms of their robustness to different noises. The methods either computed the average firing rate within frequency channels (spectral features) or inter-spike-intervals (timing features) from the simulated auditory nerve response. When used as the front-end for an automatic speech recognizer, timing features outperformed spectral features in Gaussian noise. However, this advantage was lost in babble, because timing features extracted the spectro-temporal structure of babble noise, which is similar to the target speaker. This suggests that different feature extraction methods are optimal depending on the background noise.

  4. Fiber

    Science.gov (United States)

    ... fiber you get from the food. Fiber-rich foods offer health benefits when eaten raw or cooked. Alternative Names Diet - fiber; Roughage; Bulk; Constipation - fiber Patient Instructions Constipation - ...

  5. Assesment of the Retinal Nerve Fiber Layer Thickness with Optical Coherence Tomography in Patients with Psoriasis

    Directory of Open Access Journals (Sweden)

    Emine Nur Rifaioğlu

    2014-12-01

    Full Text Available Objective: Psoriasis is an auto inflammatory disorder that affects the skin and joints. Psoriasis-related conditions that involve the eye are mainly blepharitis, conjunctivitis and keratitis and these conditions are seen in about 10% of psoriasis patients. However optic neuritis and pathologies of visual fields are rarely seen. Our study aims to investigate the mean retinal nerve fibres layer (RNFL thickness using OCT in patient psoriasis. Methods: A total of 40 patients with psoriasis and 35 controls were included in our study. The average retinal nerve fibre layer thickness was measured using the optic disc cube protocol (200x200 and the Cirrus SD-OCT (Carl Zeiss Meditec, Dublin, CA device. The statistical analyses were performed using the SPSS v 19 software programme. Results: The mean psoriasis area and severity index (PASI was 8.04 and the mean disease duration was 8.9 years. The average RNFL thickness was not statistically different between the patients and the controls, and there was no correlation between the mean RNFL thickness and the severity and duration of the disease. Conclusion: To our knowledge this study is the first assessment of RNFL thickness in patient with psoriasis. However, of greater scope are needed to investigate possible retinal changes in such patients.

  6. Subtle changes in myelination due to childhood experiences: label-free microscopy to infer nerve fibers morphology and myelination in brain (Conference Presentation)

    Science.gov (United States)

    Gasecka, Alicja; Tanti, Arnaud; Lutz, Pierre-Eric; Mechawar, Naguib; Cote, Daniel C.

    2017-02-01

    Adverse childhood experiences have lasting detrimental effects on mental health and are strongly associated with impaired cognition and increased risk of developing psychopathologies. Preclinical and neuroimaging studies have suggested that traumatic events during brain development can affect cerebral myelination particularly in areas and tracts implicated in mood and emotion. Although current neuroimaging techniques are quite powerful, they lack the resolution to infer myelin integrity at the cellular level. Recently demonstrated coherent Raman microscopy has accomplished cellular level imaging of myelin sheaths in the nervous system. However, a quantitative morphometric analysis of nerve fibers still remains a challenge. In particular, in brain, where fibres exhibit small diameters and varying local orientation. In this work, we developed an automated myelin identification and analysis method that is capable of providing a complete picture of axonal myelination and morphology in brain samples. This method performs three main procedures 1) detects molecular anisotropy of membrane phospholipids based on polarization resolved coherent Raman microscopy, 2) identifies regions of different molecular organization, 3) calculates morphometric features of myelinated axons (e.g. myelin thickness, g-ratio). We applied this method to monitor white matter areas from suicides adults that suffered from early live adversity and depression compared to depressed suicides adults and psychiatrically healthy controls. We demonstrate that our method allows for the rapid acquisition and automated analysis of neuronal networks morphology and myelination. This is especially useful for clinical and comparative studies, and may greatly enhance the understanding of processes underlying the neurobiological and psychopathological consequences of child abuse.

  7. Post-cracking behavior of blocks, prisms, and small concrete walls reinforced with plant fiber

    Directory of Open Access Journals (Sweden)

    I. I. Soto

    Full Text Available Structural masonry using concrete blocks promotes the rationalization of construction projects, lowering the final cost of a building through the elimination of forms and the reduction of the consumption of reinforcement bars. Moreover, production of a block containing a combination of concrete and vegetable fiber sisal results in a unit with properties such as mechanical strength, stiffness, flexibility, ability to absorb energy, and post-cracking behavior that are comparable to those of a block produced with plain concrete. Herein are reported the results of a study on the post-cracking behavior of blocks, prisms, and small walls reinforced with sisal fibers (lengths of 20 mm and 40 mm added at volume fractions of 0.5% and 1%. Tests were performed to characterize the fibers and blocks and to determine the compressive strength of the units, prisms, and small walls. The deformation modulus of the elements was calculated and the stress-strain curves were plotted to gain a better understanding of the values obtained. The compression test results for the small walls reinforced with fibers were similar to those of the reference walls and better than the blocks and prisms with added fibers, which had resistances lower than those of the corresponding conventional materials. All elements prepared with the addition of sisal exhibited an increase in the deformation capacity (conferred by the fibers, which was observed in the stress-strain curves. The failure mode of the reference elements was characterized by an abrupt fracture, whereas the reinforced elements underwent ductile breakage. This result was because of the presence of the fibers, which remained attached to the faces of the cracks via adhesion to the cement matrix, thus preventing loss of continuity in the material. Therefore, the cement/plant fiber composites are advantageous in terms of their ductility and ability to resist further damage after cracking.

  8. The Expanded Bead Size of Corneal C-Nerve Fibers Visualized by Corneal Confocal Microscopy Is Associated with Slow Conduction Velocity of the Peripheral Nerves in Patients with Type 2 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Fukashi Ishibashi

    2016-01-01

    Full Text Available This study aims to establish the corneal nerve fiber (CNF morphological alterations in a large cohort of type 2 diabetic patients and to investigate the association between the bead size, a novel parameter representing composite of accumulated mitochondria, glycogen particles, and vesicles in CNF, and the neurophysiological dysfunctions of the peripheral nerves. 162 type 2 diabetic patients and 45 healthy control subjects were studied in detail with a battery of clinical and neurological examinations and corneal confocal microscopy. Compared with controls, patients had abnormal CNF parameters. In particular the patients had reduced density and length of CNF and beading frequency and increased bead size. Alterations in CNF parameters were significant even in patients without neuropathy. The HbA1c levels were tightly associated with the bead size, which was inversely related to the motor and sensory nerve conduction velocity (NCV and to the distal latency period of the median nerve positively. The CNF density and length positively correlated with the NCV and amplitude. The hyperglycemia-induced expansion of beads in CNF might be a predictor of slow NCV in peripheral nerves in type 2 diabetic patients.

  9. Evaluation of changes in retinal nerve fiber layer thickness and visual functions in cases of optic neuritis and multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Rohit Saxena

    2013-01-01

    Full Text Available Context: Retinal nerve fiber layer (RNFL thinning has been demonstrated in cases of optic neuritis (ON and multiple sclerosis (MS in Caucasian eyes, but no definite RNFL loss pattern or association with visual functions is known in Indian eyes. Aim : To evaluate RNFL thickness in cases of ON and MS, and to correlate it with visual function changes in Indian patients. Settings and Design: Cross-sectional case-control study at a tertiary level institution . Materials and Methods: Cases consisted of patients of (i typical ON without a recent episode (n = 30:39 ON eyes and 21 fellow eyes, (ii MS without ON (n = 15;30 eyes while the controls were age-matched (n = 15; 30 eyes. RNFL thickness was measured using the Stratus 3 °CT. The visual functions tested included the best-corrected visual acuity (BCVA, contrast sensitivity, stereopsis, visual evoked responses, and visual fields. Statistical analysis used: Intergroup analysis was done using ANOVA and Pearson′s correlation coefficient used for associations. Results: RNFL thickness was reduced significantly in the ON and MS patients compared to the controls (P-0.001. Maximum loss is in the temporal quadrant. Lower visual function scores are associated with reduced average overall RNFL thickness. In ON group, RNFL thinning is associated with severe visual field defects while contrast sensitivity has strongest correlation with RNFL in the MS group. Conclusions:RNFL thickness is reduced in ON and MS cases in a pattern similar to Caucasians and is associated with the magnitude of impairment of other visual parameters. Contrast sensitivity and stereoacuity are useful tests to identify subclinical optic nerve involvement in multiple sclerosis.

  10. Macular Ganglion Cell Inner Plexiform Layer Thickness in Glaucomatous Eyes with Localized Retinal Nerve Fiber Layer Defects.

    Directory of Open Access Journals (Sweden)

    Chunwei Zhang

    Full Text Available To investigate macular ganglion cell-inner plexiform layer (mGCIPL thickness in glaucomatous eyes with visible localized retinal nerve fiber layer (RNFL defects on stereophotographs.112 healthy and 149 glaucomatous eyes from the Diagnostic Innovations in Glaucoma Study (DIGS and the African Descent and Glaucoma Evaluation Study (ADAGES subjects had standard automated perimetry (SAP, optical coherence tomography (OCT imaging of the macula and optic nerve head, and stereoscopic optic disc photography. Masked observers identified localized RNFL defects by grading of stereophotographs.47 eyes had visible localized RNFL defects on stereophotographs. Eyes with visible localized RNFL defects had significantly thinner mGCIPL thickness compared to healthy eyes (68.3 ± 11.4 μm versus 79.2 ± 6.6 μm respectively, P<0.001 and similar mGCIPL thickness to glaucomatous eyes without localized RNFL defects (68.6 ± 11.2 μm, P = 1.000. The average mGCIPL thickness in eyes with RNFL defects was 14% less than similarly aged healthy controls. For 29 eyes with a visible RNFL defect in just one hemiretina (superior or inferior mGCIPL was thinnest in the same hemiretina in 26 eyes (90%. Eyes with inferior-temporal RNFL defects also had significantly thinner inferior-temporal mGCIPL (P<0.001 and inferior mGCIPL (P = 0.030 compared to glaucomatous eyes without a visible RNFL defect.The current study indicates that presence of a localized RNFL defect is likely to indicate significant macular damage, particularly in the region of the macular that topographically corresponds to the location of the RNFL defect.

  11. Combining retinal nerve fiber layer thickness with individual retinal blood vessel locations allows modeling of central vision loss in glaucoma

    Science.gov (United States)

    Wang, Hui; Wang, Mengyu; Baniasadi, Neda; Jin, Qingying; Elze, Tobias

    2017-02-01

    Purpose: To assess whether modeling of central vision loss (CVL) due to glaucoma by optical coherence tomography (OCT) retinal nerve fiber (RNF) layer thickness (RNFLT) can be improved by including the location of the major inferior temporal retinal artery (ITA), a known correlate of individual RNF geometry. Methods: Pat- tern deviations of the two locations of the Humphrey 24-2 visual field (VF) known to be specifically vulnerable to glaucomatous CVL and OCT RNFLT on the corresponding circumpapillary sector around the optic nerve head within the radius of 1.73mm were retrospectively selected from 428 eyes of 428 patients of a large clinical glaucoma service. ITA was marked on the 1.73mm circle by a trained observer. Linear regression models were fitted with CVL as dependent variable and VF mean deviation (MD) plus either of (1) RNFLT, (2) ITA, and (3) their combination, respectively, as regressors. To assess CVL over all levels of glaucoma severity, the three models were compared to a null model containing only MD. A Baysian model comparison was performed with the Bayes Factor (BF) as measure of strength of evidence (BF20: strong evidence over null model). Results: Neither RNFLT (BF=0.9) nor ITA (BF=1.4) alone provided positive evidence over the null model, but their combination resulted in a model with strong evidence (BF=21.4). Conclusion: While the established circumpapillary RNFLT sector, based on population statistics, could not satisfactorily model CVL, the inclusion of a retinal parameter related to individual eye anatomy yielded a strong structure-function model.

  12. Phenotypic changes of Schwann cells on the proximal stump of injured peripheral nerve during repair using small gap conduit tube

    Directory of Open Access Journals (Sweden)

    Shi-jun Zhang

    2017-01-01

    Full Text Available Dedifferentiation of Schwann cells is an important feature of the response to peripheral nerve injury and specific negative myelination regulators are considered to have a major role in this process. However, most experiments have focused on the distal nerve stump, where the Notch signaling pathway is strongly associated with Schwann cell dedifferentiation and repair of the nerve. We observed the phenotypic changes of Schwann cells and changes of active Notch signaling on the proximal stump during peripheral nerve repair using small gap conduit tubulization. Eighty rats, with right sciatic nerve section of 4 mm, were randomly assigned to conduit bridging group and control group (epineurium suture. Glial fibrillary acidic protein expression, in myelinating Schwann cells on the proximal stump, began to up-regulate at 1 day after injury and was still evident at 5 days. Compared with the control group, Notch1 mRNA was expressed at a higher level in the conduit bridging group during the first week on the proximal stump. Hes1 mRNA levels in the conduit bridging group significantly increased compared with the control group at 3, 5, 7 and 14 days post-surgery. The change of the Notch intracellular domain shared a similar trend as Hes1 mRNA expression. Our results confirmed that phenotypic changes of Schwann cells occurred in the proximal stump. The differences in these changes between the conduit tubulization and epineurium suture groups correlate with changes in Notch signaling. This suggests that active Notch signaling might be a key mechanism during the early stage of neural regeneration in the proximal nerve stump.

  13. Clinical studies of surgical methods for small papillary thyroid cancers and prevention of recurrent laryngeal nerve injury

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    Jian-miao HE

    2016-12-01

    Full Text Available Objective  To investigate the surgical methods for thyroid microcarcinoma (TMC and prevention of recurrent laryngeal nerve injury. Methods  We retrospectively analyzed 238 TMC patients during the January 2006 to December 2013 in 309 Hospital of PLA. All the 238 patients had no clinical symptoms and the diagnosis was made by thyroid ultrasound. Thyroid ultrasound exhibited very small nodules (<1cm. At preoperation, 84 patients received fine needle aspiration (FNA. Among the 84 patients, 72 were diagnosed with TMC and 12 were false-negative for TMC by FNA. The remaining was proved by postoperative pathological examination. All of these 238 cases, 144 were of unilateral and solitary, 46 unilateral and multiple, and the remaining 48 multiple unilateral. Results  Ninety-seven patients were operated for affected side and isthmus resection plus contralateral subtotal resection, 56 for affected side plus isthmus resection, 23 for bilateral thyroid resection, 62 for bilateral thyroid subtotal resection. 132 patients underwent cervical lymph node dissection and the remaining 106 did not. During operation, the recurrent laryngeal nerve was exposed in 122 patients, involving a total of 182 recurrent laryngeal nerves. In the postoperative period (1–7 years, 6 cases of recurrent and 6 cases of laryngeal nerve injury were found. Conclusions  High-intensity focused ultrasound (HIFU is an important method for diagnosis of TMC. FNA is the most reliable procedure for preoperative determination of the nature of thyroid nodule. Finally, the reasonable and effective surgery is the key to optimize the long-term therapeutic effect and reduce side-effects. During thyroid surgery, to expose and protect recurrent laryngeal nerve is the best means for preventing injury to the recurrent laryngeal nerve. DOI: 10.11855/j.issn.0577-7402.2016.11.10

  14. Relevance Vector Machine and Support Vector Machine Classifier Analysis of Scanning Laser Polarimetry Retinal Nerve Fiber Layer Measurements

    Science.gov (United States)

    Bowd, Christopher; Medeiros, Felipe A.; Zhang, Zuohua; Zangwill, Linda M.; Hao, Jiucang; Lee, Te-Won; Sejnowski, Terrence J.; Weinreb, Robert N.; Goldbaum, Michael H.

    2010-01-01

    Purpose To classify healthy and glaucomatous eyes using relevance vector machine (RVM) and support vector machine (SVM) learning classifiers trained on retinal nerve fiber layer (RNFL) thickness measurements obtained by scanning laser polarimetry (SLP). Methods Seventy-two eyes of 72 healthy control subjects (average age = 64.3 ± 8.8 years, visual field mean deviation =−0.71 ± 1.2 dB) and 92 eyes of 92 patients with glaucoma (average age = 66.9 ± 8.9 years, visual field mean deviation =−5.32 ± 4.0 dB) were imaged with SLP with variable corneal compensation (GDx VCC; Laser Diagnostic Technologies, San Diego, CA). RVM and SVM learning classifiers were trained and tested on SLP-determined RNFL thickness measurements from 14 standard parameters and 64 sectors (approximately 5.6° each) obtained in the circumpapillary area under the instrument-defined measurement ellipse (total 78 parameters). Tenfold cross-validation was used to train and test RVM and SVM classifiers on unique subsets of the full 164-eye data set and areas under the receiver operating characteristic (AUROC) curve for the classification of eyes in the test set were generated. AUROC curve results from RVM and SVM were compared to those for 14 SLP software-generated global and regional RNFL thickness parameters. Also reported was the AUROC curve for the GDx VCC software-generated nerve fiber indicator (NFI). Results The AUROC curves for RVM and SVM were 0.90 and 0.91, respectively, and increased to 0.93 and 0.94 when the training sets were optimized with sequential forward and backward selection (resulting in reduced dimensional data sets). AUROC curves for optimized RVM and SVM were significantly larger than those for all individual SLP parameters. The AUROC curve for the NFI was 0.87. Conclusions Results from RVM and SVM trained on SLP RNFL thickness measurements are similar and provide accurate classification of glaucomatous and healthy eyes. RVM may be preferable to SVM, because it provides a

  15. Retinal nerve fiber layer analysis with scanning laser polarimetry and RTVue-OCT in patients of retinitis pigmentosa.

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    Xue, Kang; Wang, Min; Chen, Junyi; Huang, Xin; Xu, Gezhi

    2013-01-01

    To measure the thickness of the retinal nerve fiber layer (RNFL) of patients with retinitis pigmentosa (RP) and that of normal controls by scanning laser polarimetry with enhanced corneal compensation (GDxECC) and RTVue-optical coherence tomography (OCT). Fifty-two eyes of 26 patients were included. All patients underwent complete ophthalmological examinations and testing with GDxECC. Twenty-eight of 52 eyes of RP patients underwent RTVue-OCT measurements. A group of 50 eyes of 25 normal subjects (controls) was also included. GDxECC measured RNFL thickness in the peripapillary area in all subjects as well as temporal-superior-nasal-inferior-temporal (TSNIT) parameters, including TSNIT means, superior and inferior region means, TSNIT standard deviation (SD), inter-eye symmetry and nerve fiber indicator (NFI). RTVue-OCT measured the mean, superior, inferior, temporal and nasal quadrant RNFL thickness. In RP patients and controls, TSNIT means by GDxECC were, respectively, 65.00 ± 7.35 and 55.32 ± 5.20. Mean superior quadrant thicknesses were 80.56 ± 10.93 and 69.54 ± 7.45. Mean inferior thicknesses were 80.58 ± 9.34 and 69.12 ± 7.78. SDs were 27.92 ± 5.21 and 28.23 ± 4.01. Inter-eye symmetries were 0.82 ± 0.17 and 0.87 ± 0.09. NFIs were 9.74 ± 8.73 and 16.81 ± 8.13. The differences between mean TSNIT, mean superior and mean inferior quadrant thicknesses and NFIs were statistically significant (p < 0.001). In RTVue-OCT measurements, the differences between mean, superior, inferior and temporal quadrant RNFL thicknesses were statistically significant (p = 0.0322, 0.0213, 0.0387, 0.0005). The RNFL measured by GDxECC was significantly thicker in RP patients than in controls. RNFL thickness measured by RTVue-OCT was significantly greater in RP patients than in controls in the superior, inferior and temporal regions. This contribution provides information on RNFL thickness and discusses the mechanism underlying this phenomenon. Copyright © 2012 S. Karger AG

  16. An experimental study on flexural strength enhancement of concrete by means of small steel fibers

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    Abdoullah Namdar

    2013-10-01

    Full Text Available Cost effective improvement of the mechanical performances of structural materials is an important goal in construction industry. To improve the flexural strength of plain concrete so as to reduce construction costs, the addition of fibers to the concrete mixture can be adopted. The addition of small steel fibers with different lengths and proportion have experimentally been analyzed in terms of concrete flexural strength enhancement. The main objectives of the present study are related to the evaluation of the influence of steel fibers design on the increase of concrete flexural characteristics and on the mode of failure. Two types of beams have been investigated. The force level, deflection and time to failure of beams have been measured. The shear crack, flexural crack and intermediate shear-flexural crack have been studied. The steel fiber content controlled crack morphology. Flexural strength and time to failure of fiber reinforce concrete could be further enhanced if, instead of smooth steel fibers, corrugated fibers were used.

  17. EXPRESS: Methylcobalamin ameliorates neuropathic pain induced by vincristine in rats: Effect on loss of peripheral nerve fibers and imbalance of cytokines in the spinal dorsal horn.

    Science.gov (United States)

    Xu, Jing; Wang, Wei; Zhong, Xiong-Xiong; Feng, Yiwei; Wei, Xuhong; Liu, Xian-Guo

    2016-01-01

    Vincristine, a widely used chemotherapeutic agent, often induces painful peripheral neuropathy and there are currently no effective drugs to prevent or treat this side effect. Previous studies have shown that methylcobalamin has potential analgesic effect in diabetic and chronic compression of dorsal root ganglion model; however, whether methylcobalamin has effect on vincristine-induced painful peripheral neuropathy is still unknown. We found that vincristine-induced mechanical allodynia and thermal hyperalgesia, accompanied by a significant loss of intraepidermal nerve fibers in the plantar hind paw skin and an increase in the incidence of atypical mitochondria in the sciatic nerve. Moreover, in the spinal dorsal horn, the activity of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase and the protein expression of p-p65 as well as tumor necrosis factor a was increased, whereas the protein expression of IL-10 was decreased following vincristine treatment. Furthermore, intraperitoneal injection of methylcobalamin could dose dependently attenuate vincristine-induced mechanical allodynia and thermal hyperalgesia, which was associated with intraepidermal nerve fibers rescue, and atypical mitochondria prevalence decrease in the sciatic nerve. Moreover, methylcobalamin inhibited the activation of NADPH oxidase and the downstream NF-kB pathway. Production of tumor necrosis factor a was also decreased and production of IL-10 was increased in the spinal dorsal horn following methylcobalamin treatment. Intrathecal injection of Phorbol-12-Myristate-13-Acetate, a NADPH oxidase activator, could completely block the analgesic effect of methylcobalamin. Methylcobalamin attenuated vincrinstine-induced neuropathic pain, which was accompanied by inhibition of intraepidermal nerve fibers loss and mitochondria impairment. Inhibiting the activation of NADPH oxidase and the downstream NF-kB pathway, resulting in the rebalancing of proinflammatory and anti-inflammatory cytokines

  18. Sensitive Detection of Small Particles in Fluids Using Optical Fiber Tip with Dielectrophoresis

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    Yi-Hsin Tai

    2016-02-01

    Full Text Available This work presents using a tapered fiber tip coated with thin metallic film to detect small particles in water with high sensitivity. When an AC voltage applied to the Ti/Al coated fiber tip and indium tin oxide (ITO substrate, a gradient electric field at the fiber tip induced attractive/repulsive force to suspended small particles due to the frequency-dependent dielectrophoresis (DEP effect. Such DEP force greatly enhanced the concentration of the small particles near the tip. The increase of the local concentration also increased the scattering of surface plasmon wave near the fiber tip. Combined both DEP effect and scattering optical near-field, we show the detection limit of the concentration for 1.36 μm polystyrene beads can be down to 1 particle/mL. The detection limit of the Escherichia coli (E. coli bacteria was 20 CFU/mL. The fiber tip sensor takes advantages of ultrasmall volume, label-free and simple detection system.

  19. Energy losses in thermally cycled optical fibers constrained in small bend radii

    Energy Technology Data Exchange (ETDEWEB)

    Guild, Eric; Morelli, Gregg

    2012-09-23

    High energy laser pulses were fired into a 365μm diameter fiber optic cable constrained in small radii of curvature bends, resulting in a catastrophic failure. Q-switched laser pulses from a flashlamp pumped, Nd:YAG laser were injected into the cables, and the spatial intensity profile at the exit face of the fiber was observed using an infrared camera. The transmission of the radiation through the tight radii resulted in an asymmetric intensity profile with one half of the fiber core having a higher peak-to-average energy distribution. Prior to testing, the cables were thermally conditioned while constrained in the small radii of curvature bends. Single-bend, double-bend, and U-shaped eometries were tested to characterize various cable routing scenarios.

  20. Age and Glaucoma-Related Characteristics in Retinal Nerve Fiber Layer and Choroid: Localized Morphometrics and Visualization Using Functional Shapes Registration

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    Sieun Lee

    2017-07-01

    Full Text Available Optical coherence tomography provides high-resolution 3D imaging of the posterior segment of the eye. However, quantitative morphological analysis, particularly relevant in retinal degenerative diseases such as glaucoma, has been confined to simple sectorization and averaging with limited spatial sensitivity for detection of clinical markers. In this paper, we present point-wise analysis and visualization of the retinal nerve fiber layer and choroid from cross-sectional data using functional shapes (fshape registration. The fshape framework matches two retinas, or generates a mean of multiple retinas, by jointly optimizing the surface geometry and functional signals mapped on the surface. We generated group-wise mean retinal nerve fiber layer and choroidal surfaces with the respective layer thickness mapping and showed the difference by age (normal, younger vs. older and by disease (age-matched older, normal vs. glaucomatous in the two layers, along with a more conventional sector-based analysis for comparison. The fshape results visualized the detailed spatial patterns of the differences between the age-matched normal and glaucomatous retinal nerve fiber layers, with the glaucomatous layers most significantly thinner in the inferior region close to Bruch's membrane opening. Between the young and older normal cases, choroid was shown to be significantly thinner in the older subjects across all regions, but particularly in the nasal and inferior regions. The results demonstrate a comprehensive and detailed analysis with visualization of morphometric patterns by multiple factors.

  1. Differences between generalized q-sampling imaging and diffusion tensor imaging in the preoperative visualization of the nerve fiber tracts within peritumoral edema in brain.

    Science.gov (United States)

    Zhang, Hongliang; Wang, Yong; Lu, Tao; Qiu, Bo; Tang, Yanqing; Ou, Shaowu; Tie, Xinxin; Sun, Chuanqi; Xu, Ke; Wang, Yibao

    2013-12-01

    Diffusion tensor imaging (DTI) tractography enables the in vivo visualization of white matter tracts inside normal brain tissue, which provides the neurosurgeon important information to plan tumor resections. However, DTI is associated with restrictions in the resolution of crossing fibers in the vicinity of the tumor or in edema. We find that generalized q-sampling imaging (GQI) can overcome these difficulties and is advantageous over DTI for the tractography of the fiber bundle in peritumoral edema. To demonstrate the differences between GQI and DTI in the preoperative mapping of fiber tractography in peritumoral edema of cerebral tumors, and discuss the clinical application of GQI in neurosurgical planning. Five patients with brain tumors underwent 3-T magnetic resonance imaging scans, and the data were reconstructed by DTI and GQI. We adjusted the parameters and compared the differences between DTI and GQI in visualizing the fiber tracts in the peritumoral edema of cerebral tumors. GQI and DTI showed substantial differences in displaying the nerve fibers in the edema surrounding the tumor. The GQI tractography method could fully display existing intact fibers in the edema, whereas the fiber tracts in edema displayed by DTI tractography were incomplete, missing, or ruptured. GQI can visualize the tracts in the peritumoral edema of cerebral tumors better than DTI. Although GQI has many limitations, its future in the preoperative guidance of brain tumor lesions is promising.

  2. Investigation of relationship of iris color with retinal nerve fiber layer, macula and choroid thickness in healthy individuals

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    Süleyman Demircan

    2017-08-01

    Full Text Available AIM: To determine whether there was a significant relationship between eye iris color with axial length, intraocular pressure, retinal nerve fiber layer(RNFLthickness, macular thickness and choroidal thickness.METHODS: A prospective cross-sectional study involving 92 eyes of 92 healthy volunteers. These were divided into dark colored-eye(DCEand light-colored eye(LCEgroups according to iris color. The RNFL and macular thicknesses were analysed with standard optical coherence tomography(OCTprotocol while choroidal thickness was analysed with electronic data interchange(EDIprotocol in all subjects. Choroidal thickness was measured at the fovea, 1500 μm nasal and 1500 μm temporal to the fovea in a horizontal section.RESULTS: Of the 92 eyes included, 62(67.4%were dark-colored while 30(32.6%were light-colored. The mean age was 29.22±5.86y in the subjects with DCE and 28.86±6.50y in those with LCE. No significant difference was detected in mean age, axial length, macular thickness, choroidal thickness and intraocular pressure(IOPbetween the groups(P>0.05. However, RNFL thicknesses varied depending on the quadrant measured, and were lower in both global and the nasal and temporal quadrants for individuals with LCE(P≤0.022.CONCLUSION: No significant differences were found in IOP, macular thickness and choroid thickness between individuals with DCE and LCE. Meanwhile, the RNFL thickness is lower.

  3. Agreement of retinal nerve fiber layer defect location between red-free fundus photography and cirrus HD-OCT maps.

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    Hwang, Young Hoon; Kim, Yong Yeon; Kim, Hwang Ki; Sohn, Yong Ho

    2014-11-01

    To investigate the agreement of angular locations of retinal nerve fiber layer (RNFL) defect margins in glaucomatous eyes by using red-free fundus photographs and Cirrus high-definition optical coherence tomography (OCT) RNFL deviation and thickness maps. We examined 380 RNFL defects that showed clear margins in red-free fundus photographs. The OCT deviation and thickness maps were overlaid on the corresponding red-free fundus photographs. A reference line was drawn between the disc center and the macular center. Lines were also drawn between the optic disc center and the point where the RNFL defect margins crossed the OCT scan circle. The angle between the reference and defect-margin lines defined the angular location of the defect margin. Angular locations of proximal (nearest to the reference) and distal (farthest from the reference) RNFL defect margins on OCT deviation and thickness maps were compared to the locations on red-free fundus photographs. The angular locations of proximal and distal RNFL defect margins on OCT thickness maps showed good agreement with red-free fundus photographs. However, OCT deviation maps showed greater angular locations for both proximal and distal RNFL defect margins compared with red-free fundus photographs, especially in eyes with higher myopia (p maps showed good agreement for the RNFL defect margin identification. However, this was not the case for deviation maps, especially in myopic eyes. This finding should be considered when evaluating RNFL defects using OCT maps.

  4. Reverse correlation analysis of auditory-nerve fiber responses to broadband noise in a bird, the barn owl.

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    Fontaine, Bertrand; Köppl, Christine; Peña, Jose L

    2015-02-01

    While the barn owl has been extensively used as a model for sound localization and temporal coding, less is known about the mechanisms at its sensory organ, the basilar papilla (homologous to the mammalian cochlea). In this paper, we characterize, for the first time in the avian system, the auditory nerve fiber responses to broadband noise using reverse correlation. We use the derived impulse responses to study the processing of sounds in the cochlea of the barn owl. We characterize the frequency tuning, phase, instantaneous frequency, and relationship to input level of impulse responses. We show that, even features as complex as the phase dependence on input level, can still be consistent with simple linear filtering. Where possible, we compare our results with mammalian data. We identify salient differences between the barn owl and mammals, e.g., a much smaller frequency glide slope and a bimodal impulse response for the barn owl, and discuss what they might indicate about cochlear mechanics. While important for research on the avian auditory system, the results from this paper also allow us to examine hypotheses put forward for the mammalian cochlea.

  5. Meta-analysis of changes for retinal nerve fiber layer thickness of patients with obstructive sleep apnea

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    Dai-Zong Wen

    2015-08-01

    Full Text Available AIM: To investigate the difference of retinal nerve fiber layer(RNFLthickness measured with OCT between obstructive sleep apnea(OSApatients and normal people and discuss the relativity between decresse of RNFL and OSA.METHODS: The articles on the association of RNFL thickness and OSA were retrieved by searching international and national databases. The qualified articles were assessed by Meta-analysis with Stata11.0 software. RESULTS: Totally 10 studies enrolled 1 488 eyes were included in the Meta-analysis. The results of Meta-analysis showed that in OSA patients, there was a significant average RNFL thickness reduction compared with the control group. There were significant differences in superior, nasal and inferior RNFL thickness between the two groups. WMD with a 95%CI were \\〖-2.97, 95%CI:(-4.65~-1.30, P95%CI:(-4.93~-1.17, P=0.002\\〗, \\〖-3.81, 95%CI:(-6.95~-0.68, P=0.02\\〗, \\〖-4.16, 95%CI:(-7.63~-0.68, P=0.02\\〗 respectively.CONCLUSION: RNFL thickness is reduced in OSA patients compared with the control group. OCT may become a standard part of the evaluation of patients in OSA.

  6. Ability of spectral domain optical coherence tomography peripapillary retinal nerve fiber layer thickness measurements to identify early glaucoma

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    Tarannum Mansoori

    2011-01-01

    Full Text Available Purpose : To evaluate the ability of spectral domain optical coherence tomography (OCT peripapillary retinal nerve fiber layer thickness (RNFLT parameters to distinguish normal eyes from those with early glaucoma in Asian Indian eyes. Design : Observational cross-sectional study. Materials and Methods : One hundred and seventy eight eyes (83 glaucoma patients and 95 age matched healthy subjects of subjects more than 40 years of age were included in the study. All subjects underwent RNFLT measurement with spectral OCT/ scanning laser ophthalmoscope (SLO after dilatation. Sensitivity, specificity and area under the receiving operating characteristic curve (AROC were calculated for various OCT peripapillary RNFL parameters. Results: The mean RNFLT in healthy subjects and patients with early glaucoma were 105.7 ± 5.1 μm and 90.7 ± 7.5 μm, respectively. The largest AROC was found for 12 o′clock- hour (0.98, average (0.96 and superior quadrant RNFLT (0.9. When target specificity was set at ≥ 90% and ≥ 80%, the parameters with highest sensitivity were 12 o′clock -hour (91.6%, average RNFLT (85.3% and 12 o′ clock- hour (96.8 %, average RNFLT (94.7% respectively. Conclusion : Our study showed good ability of spectral OCT/ SLO to differentiate normal eyes from patients with early glaucoma and hence it may serve as an useful adjunct for early diagnosis of glaucoma.

  7. Effects of Misalignments in the Retinal Nerve Fiber Layer Thickness Measurements with Spectral Domain Optical Coherence Tomography

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    Kleyton A. Barella

    2014-01-01

    Full Text Available Purpose. To investigate misalignments (MAs on retinal nerve fiber layer thickness (RNFLT measurements obtained with Cirrus© SD-OCT. Methods. This was a retrospective, observational, cross-sectional study. Twenty-seven healthy and 29 glaucomatous eyes of 56 individuals with one normal exam and another showing MA were included. MAs were defined as an improper alignment of vertical vessels in the en face image. MAs were classified in complete MA (CMA and partial MA (PMA, according to their site: 1 (superior, outside the measurement ring (MR, 2 (superior, within MR, 3 (inferior, within MR, and 4 (inferior, outside MR. We compared RNFLT measurements of aligned versus misaligned exams in all 4 sectors, in the superior area (sectors 1 + 2, inferior area (sectors 3 + 4, and within the measurement ring (sectors 2 + 3. Results. RNFLT measurements at 12 clock-hour of eyes with MAs in the superior area (sectors 1 + 2 were significantly lower than those obtained in the same eyes without MAs P=0.043. No significant difference was found in other areas (sectors 1 + 2 + 3 + 4, sectors 3 + 4, and sectors 2 + 3. Conclusion. SD-OCT scans with superior MAs may present lower superior RNFLT measurements compared to aligned exams.

  8. Retinal nerve fiber layer thinning: a window into rapid eye movement sleep behavior disorders in Parkinson's disease.

    Science.gov (United States)

    Yang, Zi-Jiao; Wei, Jing; Mao, Cheng-Jie; Zhang, Jin-Ru; Chen, Jing; Ji, Xiao-Yan; Liu, Jun-Yi; Shen, Yun; Xiong, Kang-Ping; Huang, Jun-Ying; Yang, Ya-Ping; Liu, Chun-Feng

    2016-12-01

    Retinal nerve fiber layer (RNFL) thinning occurs in Parkinson's disease (PD) and other neurodegenerative diseases. Idiopathic RBD (iRBD) is a well-established prodromal hallmark of synucleinopathies and occurs secondary to many neurodegenerative diseases, including PD. The aim of this study is to determine whether or not retinal structures are altered with the onset of rapid eye movement (REM) sleep behavior disorders (RBD). In all, a total of 63 patients with PD, 14 patients with idiopathic RBD, and 26 sex- and age-matched healthy controls were enrolled and underwent optical coherence tomography measurements (HD-OCT (Zeiss) ) for the average and every quadrant of RNFL thickness. The REM Sleep Behavior Disorder Screening Questionnaire (RBDSQ) was used to classify PD patients with clinically probable RBD (PD + pRBD) or without probable RBD (PD - pRBD). Patients with iRBD were identified by polysomnography. For patients with RBD (idiopathic or secondary to PD), we found a significant decrease in RNFL thickness compared with groups without RBD (PD - pRBD and healthy controls) (all p treatment. Multiple linear regression analysis showed that RBDSQ score was negatively associated with average and inferior RNFL variation in PD (all p < 0.005). The findings show that RNFL was slightly but significantly thinner in idiopathic RBD. In PD, RNFL thickness may vary depending on the presence of RBD.

  9. Effect of Aging on Retinal Nerve Fiber Layer Thickness in Normal Asian Indian Eyes: A Longitudinal Study.

    Science.gov (United States)

    Mansoori, Tarannum; Balakrishna, Nagalla

    2017-02-01

    To determine longitudinal retinal nerve fiber layer (RNFL) thickness measurement change with aging, after a period of 3 years using spectral optical coherence tomography/scanning laser ophthalmoscope (OCT/SLO). A total of 50 eyes of 25 normal subjects underwent RNFL thickness measurement in 2008 and again in 2011 by a single operator, using spectral OCT/SLO. Measurements were compared at baseline and at follow-up. Linear mixed model analysis was used to measure the effect of age on RNFL thickness measurements over the 3 years. Mean RNFL thickness was 107.92 ± 11.1 µm in 2008 and 106.56 ± 10.8 µm in 2011. For every year increase in age, mean RNFL thickness showed a statistically significant decrease by -0.54 µm (95% confidence interval, -0.76 to -0.31; p thickness in most RNFL regions, except for the temporal quadrant (p = 0.37) and corresponding 7, 8, 9, and 10 o'clock hour sectors (p = 0.72, 0.75, 0.17, 0.14, respectively). RNFL thickness as measured by spectral OCT/SLO decreased significantly with advancing age over a period of 3 years, and was not uniform across the four quadrants. This age-related variation should be taken into account in RNFL thickness measurements when evaluating patients for diagnosis and follow-up of glaucoma.

  10. Modeling the response of small myelinated axons in a compound nerve to kilohertz frequency signals

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    Pelot, N. A.; Behrend, C. E.; Grill, W. M.

    2017-08-01

    Objective. There is growing interest in electrical neuromodulation of peripheral nerves, particularly autonomic nerves, to treat various diseases. Electrical signals in the kilohertz frequency (KHF) range can produce different responses, including conduction block. For example, EnteroMedics’ vBloc® therapy for obesity delivers 5 kHz stimulation to block the abdominal vagus nerves, but the mechanisms of action are unclear. Approach. We developed a two-part computational model, coupling a 3D finite element model of a cuff electrode around the human abdominal vagus nerve with biophysically-realistic electrical circuit equivalent (cable) model axons (1, 2, and 5.7 µm in diameter). We developed an automated algorithm to classify conduction responses as subthreshold (transmission), KHF-evoked activity (excitation), or block. We quantified neural responses across kilohertz frequencies (5-20 kHz), amplitudes (1-8 mA), and electrode designs. Main results. We found heterogeneous conduction responses across the modeled nerve trunk, both for a given parameter set and across parameter sets, although most suprathreshold responses were excitation, rather than block. The firing patterns were irregular near transmission and block boundaries, but otherwise regular, and mean firing rates varied with electrode-fibre distance. Further, we identified excitation responses at amplitudes above block threshold, termed ‘re-excitation’, arising from action potentials initiated at virtual cathodes. Excitation and block thresholds decreased with smaller electrode-fibre distances, larger fibre diameters, and lower kilohertz frequencies. A point source model predicted a larger fraction of blocked fibres and greater change of threshold with distance as compared to the realistic cuff and nerve model. Significance. Our findings of widespread asynchronous KHF-evoked activity suggest that conduction block in the abdominal vagus nerves is unlikely with current clinical parameters. Our

  11. Porous stainless steel hollow fibers with shrinkage-controlled small radial dimensions

    NARCIS (Netherlands)

    Luiten-Olieman, Maria W.J.; Raaijmakers, Michiel; Raaijmakers, Michiel J.T.; Winnubst, Aloysius J.A.; Wessling, Matthias; Nijmeijer, Arian; Benes, Nieck Edwin

    2011-01-01

    A method is presented for the preparation of thin (∼250 μm) porous stainless steel hollow fiber membranes based on dry–wet spinning of a particle-loaded polymer solution followed by heat treatment. Extraordinarily small radial dimensions were achieved by controlled shrinkage during thermal

  12. Design of a multimodal fibers optic system for small animal optical imaging.

    Science.gov (United States)

    Spinelli, Antonello E; Pagliazzi, Marco; Boschi, Federico

    2015-02-01

    Small animals optical imaging systems are widely used in pre-clinical research to image in vivo the bio-distribution of light emitting probes using fluorescence or bioluminescence modalities. In this work we presented a set of simulated results of a novel small animal optical imaging module based on a fibers optics matrix, coupled with a position sensitive detector, devoted to acquire bioluminescence and Cerenkov images. Simulations were performed using GEANT 4 code with the GAMOS architecture using the tissue optics plugin. Results showed that it is possible to image a 30 × 30 mm region of interest using a fiber optics array containing 100 optical fibers without compromising the quality of the reconstruction. The number of fibers necessary to cover an adequate portion of a small animal is thus quite modest. This design allows integrating the module with magnetic resonance (MR) in order to acquire optical and MR images at the same time. A detailed model of the mouse anatomy, obtained by segmentation of 3D MRI images, will improve the quality of optical 3D reconstruction. Copyright © 2014 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  13. Factors Associated with the Retinal Nerve Fiber Layer Loss after Acute Primary Angle Closure: A Prospective EDI-OCT Study.

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    Eun Ji Lee

    Full Text Available To determine the factors associated with retinal nerve fiber layer (RNFL loss in eyes with acute primary angle-closure (APAC, particularly focusing on the influence of the change in the anterior lamina cribrosa surface depth (LCD.After the initial presentation, 30 eyes with unilateral APAC were followed up at the following specific time points over a 12-month period: 1 week, 1~2 months, 2~3 months, 5~6 months, and 11~12 months. These follow-ups involved intraocular pressure measurements, enhanced depth-imaging spectral-domain optical coherence tomography (SD-OCT scanning of the optic disc, and measurements of the circumpapillary RNFL thickness. The prelaminar tissue thickness (PLT and LCD were determined in the SD-OCT images obtained at each follow-up visit.Repeated measures analysis of variance revealed a significant pattern of decrease in the global RNFL thickness, PLT, and LCD (all p<0.001. The global RNFL thickness decreased continuously throughout the follow-up period, while the PLT decreased until 5~6 months and did not change thereafter. The LCD reduced until 2~3 months and then also remained steady. Multivariable regression analysis revealed that symptoms with a longer duration before receiving laser peripheral iridotomy (LI (p = 0.049 and a larger LCD reduction (p = 0.034 were significant factors associated with the conversion to an abnormal RNFL thickness defined using OCT normative data.Early short-term decreases in the PLT and LCD and overall long-term decrease in the peripapillary RNFL were observed during a 12-month follow-up after an APAC episode. A longer duration of symptoms before receiving LI treatment and larger LCD reduction during follow-up were associated with the progressive RNFL loss. The LCD reduction may indicate a prior presence of significant pressure-induced stress that had been imposed on the optic nerve head at the time of APAC episode. Glaucomatous progression should be suspected in eyes showing LCD reduction

  14. Exuberant sprouting of sensory and sympathetic nerve fibers in nonhealed bone fractures and the generation and maintenance of chronic skeletal pain.

    Science.gov (United States)

    Chartier, Stephane R; Thompson, Michelle L; Longo, Geraldine; Fealk, Michelle N; Majuta, Lisa A; Mantyh, Patrick W

    2014-11-01

    Skeletal injury is a leading cause of chronic pain and long-term disability worldwide. While most acute skeletal pain can be effectively managed with nonsteroidal anti-inflammatory drugs and opiates, chronic skeletal pain is more difficult to control using these same therapy regimens. One possibility as to why chronic skeletal pain is more difficult to manage over time is that there may be nerve sprouting in nonhealed areas of the skeleton that normally receive little (mineralized bone) to no (articular cartilage) innervation. If such ectopic sprouting did occur, it could result in normally nonnoxious loading of the skeleton being perceived as noxious and/or the generation of a neuropathic pain state. To explore this possibility, a mouse model of skeletal pain was generated by inducing a closed fracture of the femur. Examined animals had comminuted fractures and did not fully heal even at 90+days post fracture. In all mice with nonhealed fractures, exuberant sensory and sympathetic nerve sprouting, an increase in the density of nerve fibers, and the formation of neuroma-like structures near the fracture site were observed. Additionally, all of these animals exhibited significant pain behaviors upon palpation of the nonhealed fracture site. In contrast, sprouting of sensory and sympathetic nerve fibers or significant palpation-induced pain behaviors was never observed in naïve animals. Understanding what drives this ectopic nerve sprouting and the role it plays in skeletal pain may allow a better understanding and treatment of this currently difficult-to-control pain state. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  15. Increased nerve fiber expression of sensory sodium channels Nav1.7, Nav1.8, And Nav1.9 in rhinitis.

    Science.gov (United States)

    Keh, Siew M; Facer, Paul; Simpson, Karen D; Sandhu, Guri; Saleh, Hesham A; Anand, Praveen

    2008-04-01

    Voltage-gated sodium channels Nav1.7, Nav1.8, and Nav1.9 are involved in nerve action potentials and have been proposed to underlie neuronal hypersensitivity. We have therefore studied their levels in allergic and nonallergic rhinitis. Inferior turbinate biopsies from 50 patients (n = 18 controls, n = 20 allergic, and n = 12 nonallergic rhinitis) were studied by immunohistology using antibodies to Nav1.7, Nav1.8, and Nav1.9, the structural nerve marker (protein gene product [PGP]9.5), nerve growth factor (NGF), mast cells (c-kit), macrophages (CD68), and T cells (CD3). Sodium channel-positive nerve fibers were counted per millimeter length of subepithelium, and immunoreactivity for inflammatory cell markers PGP9.5 and NGF were image analyzed. All three sodium channel-immunoreactive nerve fiber numbers were significantly increased in allergic (Nav1.7, P = .0004; Nav1.8, P = .028; Nav1.9, P = .02) and nonallergic (Nav1.7, P = .006; Nav1.8, P = .019; Nav1.9, P = .0037) rhinitis. There was a significant increase of subepithelial innervation (PGP9.5, P = .01) and epithelial NGF immunoreactivity (P = .03) in nonallergic rhinitis, comparable with our previous report in allergic rhinitis. Inflammatory cell markers were significantly increased in allergic (mast cells, P = .06; macrophages, P = .044; T cells, P = .007) but not nonallergic rhinitis. The increased levels of sensory sodium channels in allergic and nonallergic rhinitis may contribute to the hypersensitive state, irrespective of the degree of active inflammation. Selective blockers of these sodium channels, administered topically, may have therapeutic potential in rhinitis.

  16. Risk markers for development of small and large nerve fiber lesion in patients with diabetes

    Czech Academy of Sciences Publication Activity Database

    Malá, S.; Potočková, V.; Hoskovcová, L.; Brabec, Marek; Brož, J.; Kvapil, M.

    2016-01-01

    Roč. 59, 1 Suppl (2016), S462-S462 ISSN 0012-186X. [EASD Annual Meeting /52./. 12.09.2016-16.09.2016, Munich] Institutional support: RVO:67985807 Keywords : diabetes * markers Subject RIV: FB - Endocrinology, Diabetology, Metabolism, Nutrition

  17. Retractor-endoscopic nerve decompression in carpal and cubital tunnel syndromes: outcomes in a small series.

    Science.gov (United States)

    Martin, K-Daniel; Dützmann, Stephan; Sobottka, Stephan B; Rambow, Stefanie; Mellerowicz, Helene A; Pinzer, Thomas; Schackert, Gabriele; Krishnan, Kartik G

    2014-01-01

    To present midterm to long-term results obtained in carpal tunnel release, in situ decompression, and anterior transposition of the ulnar nerve using the retractor integrated endoscope. During the period 2000-2010, 145 patients underwent endoscopic carpal tunnel releases (n = 47), endoscopic in situ decompression of the ulnar nerve (n = 55), and endoscopic anterior transposition of the ulnar nerve (n = 52). Bilateral surgery was performed in 9 patients. Independent examinations at 24 months after surgery were used for objective results (Bishop score). Subjective results were procured using a questionnaire. After endoscopic carpal tunnel release, 59.6% of patients showed excellent results, 21.2% showed good results, 12.8% showed fair results, and 6.4% showed poor results according to objective scoring. In 85% of patients, subjective improvement was noted after surgery; symptoms were the same as before surgery in 12.8% of patients and were worse in 2.1% of patients after surgery. After endoscopic in situ decompression, 56.4% of patients showed excellent results on objective scoring, 32.7% showed good results, 9.1% showed fair results, and 1.8% showed poor results. On subjective questioning, 72.7% of patients reported improvement, 20% reported no change in symptoms, and 7.3% reported worse symptoms. After endoscopic anterior transposition of the ulnar nerve, 48.1% of patients showed excellent results on objective scoring, 26.9% showed good results, 23.1% showed fair results, and 1.9% showed poor results. Subjectively, 65.4% of patients reported improvement, 26.9% reported no change in symptoms, and 7.7% reported worse symptoms. Patients with symptom duration of 9 months. The retractor-endoscopic technique provides good long-term results after carpal tunnel release, in situ decompression, and anterior subcutaneous transposition of the ulnar nerve. Outcomes showed some correlation to the duration of preoperative symptoms. Copyright © 2014 Elsevier Inc. All rights

  18. Development of a small scintillation detector with an optical fiber for fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Yagi, T., E-mail: takahiro@rri.kyoto-u.ac.j [Graduate School of Energy Science, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto 606-8501 (Japan); Unesaki, H.; Misawa, T.; Pyeon, C.H.; Shiroya, S. [Research Reactor Institute, Kyoto University, Asashiro-nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494 (Japan); Matsumoto, T.; Harano, H. [National Institute of Advanced Industrial Science and Technology, Umezomo, Tsukuca, Ibaraki 305-8668 (Japan)

    2011-02-15

    To investigate the characteristics of a reactor and a neutron generator, a small scintillation detector with an optical fiber with ThO{sub 2} has been developed to measure fast neutrons. However, experimental facilities where {sup 232}Th can be used are limited by regulations, and S/N ratio is low because the background counts of this detector are increase by alpha decay of {sup 232}Th. The purpose of this study is to develop a new optical fiber detector for measuring fast neutrons that does not use nuclear material such as {sup 232}Th. From the measured and calculated results, the new optical fiber detector which uses ZnS(Ag) as a converter material together with a scintillator have the highest detection efficiency among several developed detectors. It is applied for the measurement of reaction rates generated from fast neutrons; furthermore, the absolute detection efficiency of this detector was obtained experimentally.

  19. Development of a small scintillation detector with an optical fiber for fast neutrons.

    Science.gov (United States)

    Yagi, T; Unesaki, H; Misawa, T; Pyeon, C H; Shiroya, S; Matsumoto, T; Harano, H

    2011-02-01

    To investigate the characteristics of a reactor and a neutron generator, a small scintillation detector with an optical fiber with ThO(2) has been developed to measure fast neutrons. However, experimental facilities where (232)Th can be used are limited by regulations, and S/N ratio is low because the background counts of this detector are increase by alpha decay of (232)Th. The purpose of this study is to develop a new optical fiber detector for measuring fast neutrons that does not use nuclear material such as (232)Th. From the measured and calculated results, the new optical fiber detector which uses ZnS(Ag) as a converter material together with a scintillator have the highest detection efficiency among several developed detectors. It is applied for the measurement of reaction rates generated from fast neutrons; furthermore, the absolute detection efficiency of this detector was obtained experimentally. Copyright © 2010 Elsevier Ltd. All rights reserved.

  20. Cranial Nerve Disorders in Children: MR Imaging Findings.

    Science.gov (United States)

    Hwang, Jae-Yeon; Yoon, Hye-Kyung; Lee, Jeong Hyun; Yoon, Hee Mang; Jung, Ah Young; Cho, Young Ah; Lee, Jin Seong; Yoon, Chong Hyun

    2016-01-01

    Cranial nerve disorders are uncommon disease conditions encountered in pediatric patients, and can be categorized as congenital, inflammatory, traumatic, or tumorous conditions that involve the cranial nerve itself or propagation of the disorder from adjacent organs. However, determination of the normal course, as well as abnormalities, of cranial nerves in pediatric patients is challenging because of the small caliber of the cranial nerve, as well as the small intracranial and skull base structures. With the help of recently developed magnetic resonance (MR) imaging techniques that provide higher spatial resolution and fast imaging techniques including three-dimensional MR images with or without the use of gadolinium contrast agent, radiologists can more easily diagnose disease conditions that involve the small cranial nerves, such as the oculomotor, abducens, facial, and hypoglossal nerves, as well as normal radiologic anatomy, even in very young children. If cranial nerve involvement is suspected, careful evaluation of the cranial nerves should include specific MR imaging protocols. Localization is an important consideration in cranial nerve imaging, and should cover entire pathways and target organs as much as possible. Therefore, radiologists should be familiar not only with the various diseases that cause cranial nerve dysfunction, and the entire course of each cranial nerve including the intra-axial nuclei and fibers, but also the technical considerations for optimal imaging of pediatric cranial nerves. In this article, we briefly review normal cranial nerve anatomy and imaging findings of various pediatric cranial nerve dysfunctions, as well as the technical considerations of pediatric cranial nerve imaging. Online supplemental material is available for this article. (©)RSNA, 2016.

  1. Details of Glaucomatous Damage Are Better Seen on OCT En Face Images Than on OCT Retinal Nerve Fiber Layer Thickness Maps.

    Science.gov (United States)

    Hood, Donald C; Fortune, Brad; Mavrommatis, Maria A; Reynaud, Juan; Ramachandran, Rithambara; Ritch, Robert; Rosen, Richard B; Muhammad, Hassan; Dubra, Alfredo; Chui, Toco Y P

    2015-10-01

    High-resolution images of glaucomatous damage to the retinal nerve fiber layer (RNFL) were obtained with an adaptive optics-scanning light ophthalmoscope (AO-SLO) and used as a basis for comparisons between en face slab images and thickness maps derived from optical coherence tomography (OCT) scans. Wide-field (9 × 12 mm) cube scans were obtained with swept-source OCT (DRI-OCT) from six eyes of six patients. All eyes had a deep defect near fixation as seen on a 10-2 visual field test. Optical coherence tomography en face images, based on the average reflectance intensity, were generated (ATL 3D-Suite) from 52-μm slabs just below the vitreal border of the inner limiting membrane. The RNFL thickness maps were generated from the same OCT data. Both were compared with the AO-SLO peripapillary images that were previously obtained. On AO-SLO images, three eyes showed small regions of preserved and/or missing RNFL bundles within the affected region. Details in these regions were seen on the OCT en face images but not on the RNFL thickness maps. In addition, in the healthier hemi-retinas of two eyes, there were darker, arcuate-shaped regions on en face images that corresponded to abnormalities seen on AO-SLO. These were not seen on RNFL thickness maps. Details of local glaucomatous damage, missing or easily overlooked on traditional OCT RNFL thickness analysis used in clinical OCT reports, were seen on OCT en face images based on the average reflectance intensity. While more work is needed, it is likely that en face slab imaging has a role in the clinical management of glaucoma.

  2. Effect of fiber length of carbon nanotubes on the absorption of erythropoietin from rat small intestine.

    Science.gov (United States)

    Ito, Yukako; Venkatesan, Natarajan; Hirako, Noriko; Sugioka, Nobuyuki; Takada, Kanji

    2007-06-07

    Erythropoietin (EPO) loaded carbon nanotubes (CNTs) with surfactant as an absorption enhancer were prepared for the oral delivery of EPO using two types of CNTs, long and short fiber length CNTs, and the effect of CNT fiber length on the absorption efficiency of EPO was studied. After Labrasol, PEG-8 caprylic/capric glycerides, as absorption enhancer was adsorbed into long fiber CNTs of which mean fiber length was 20-80 microm, as a carrier, EPO and casein as protease inhibitor and Explotab (sodium starch glycolate) as a disintegrating agent, were mixed. The resulting solid preparation was administered into the rat jejunum and serum EPO levels were measured by ELISA. The dose of EPO, CNTs, casein and Explotab were 100 IU/kg, 5mg/kg, 25mg/kg and 2.5mg/kg, respectively. Serum EPO level reached to C(max), 69.0+/-3.9 mIU/ml, at 3.5+/-0.1h and AUC was 175.7+/-13.8 mIU h/ml. These values were approximately half of that obtained with short fiber length CNTs of which C(max) was 143.1+/-15.2 mIU/ml and AUC was 256.3+/-9.7 mIU h/ml. When amphoteric surfactant, Lipomin LA, sodium beta-alkylaminopropionic acid, was used to accelerate the disaggregation of long fiber length CNTs, C(max) was 36.0+/-4.9 and AUC was 96.9+/-11.9, which showed less bioavailability (BA) of EPO. These results suggest that the short fiber length CNTs deliver more both EPO and absorption enhancer to the absorptive cells of the rat small intestine and the aggregation of CNTs is not the critical factor for the oral delivery of EPO.

  3. Influence of pregnancy and labor on the occurrence of nerve fibers expressing the capsaicin receptor TRPV1 in human corpus and cervix uteri

    Directory of Open Access Journals (Sweden)

    Irestedt Lars

    2008-02-01

    Full Text Available Abstract Background Cervical ripening is a prerequisite for a normal obstetrical outcome. This process, including labor, is a painful event that shares features with inflammatory reactions where peripheral nociceptive pathways are involved. The capsaicin and heat receptor TRPV1 is a key molecule in sensory nerves involved in peripheral nociception, but little is known regarding its role in the pregnant uterus. Therefore, the aim of this study was to investigate human corpus and cervix uteri during pregnancy and labor and non-pregnant controls for the presence of TRPV1. Methods We have investigated human uterine corpus and cervix biopsies at term pregnancy and parturition. Biopsies were taken from the upper edge of the hysterotomy during caesarean section at term (n = 8, in labor (n = 8 and from the corresponding area in the non-pregnant uterus after hysterectomy (n = 8. Cervical biopsies were obtained transvaginally from the anterior cervical lip. Serial frozen sections were examined immunohistochemically using specific antibodies to TRPV1 and nerve markers (neurofilaments/peripherin. Results In cervix uteri, TRPV1-immunoreactive fibers were scattered throughout the stroma and around blood vessels, and appeared more frequent in the sub-epithelium. Counts of TRPV1-immunoreactive nerve fibers were not significantly different between the three groups. In contrast, few TRPV1-immunoreactive fibers were found in nerve fascicles in the non-pregnant corpus, and none in the pregnant corpus. Conclusion In this study, TRPV1 innervation in human uterus during pregnancy and labor is shown for the first time. During pregnancy and labor there was an almost complete disappearance of TRPV1 positive nerve fibers in the corpus. However, cervical innervation remained throughout pregnancy and labor. The difference in TRPV1 innervation between the corpus and the cervix is thus very marked. Our data suggest that TRPV1 may be involved in pain mechanisms associated with

  4. Adaptive optics imaging of healthy and abnormal regions of retinal nerve fiber bundles of patients with glaucoma.

    Science.gov (United States)

    Chen, Monica F; Chui, Toco Y P; Alhadeff, Paula; Rosen, Richard B; Ritch, Robert; Dubra, Alfredo; Hood, Donald C

    2015-01-08

    To better understand the nature of glaucomatous damage of the macula, especially the structural changes seen between relatively healthy and clearly abnormal (AB) retinal regions, using an adaptive optics scanning light ophthalmoscope (AO-SLO). Adaptive optics SLO images and optical coherence tomography (OCT) vertical line scans were obtained on one eye of seven glaucoma patients, with relatively deep local arcuate defects on the 10-2 visual field test in one (six eyes) or both hemifields (one eye). Based on the OCT images, the retinal nerve fiber (RNF) layer was divided into two regions: (1) within normal limits (WNL), relative RNF layer thickness within mean control values ±2 SD; and (2) AB, relative thickness less than -2 SD value. As seen on AO-SLO, the pattern of AB RNF bundles near the border of the WNL and AB regions differed across eyes. There were normal-appearing bundles in the WNL region of all eyes and AB-appearing bundles near the border with the AB region. This region with AB bundles ranged in extent from a few bundles to the entire AB region in the case of one eye. All other eyes had a large AB region without bundles. However, in two of these eyes, a few bundles were seen within this region of otherwise missing bundles. The AO-SLO images revealed details of glaucomatous damage that are difficult, if not impossible, to see with current OCT technology. Adaptive optics SLO may prove useful in following progression in clinical trials, or in disease management, if AO-SLO becomes widely available and easy to use. Copyright 2015 The Association for Research in Vision and Ophthalmology, Inc.

  5. Peripapillary retinal nerve fiber layer assessment of spectral domain optical coherence tomography and scanning laser polarimetry to diagnose preperimetric glaucoma.

    Science.gov (United States)

    Rao, Harsha L; Yadav, Ravi K; Addepalli, Uday K; Chaudhary, Shashikant; Senthil, Sirisha; Choudhari, Nikhil S; Garudadri, Chandra S

    2014-01-01

    To compare the abilities of peripapillary retinal nerve fiber layer (RNFL) parameters of spectral domain optical coherence tomograph (SDOCT) and scanning laser polarimeter (GDx enhanced corneal compensation; ECC) in detecting preperimetric glaucoma. In a cross-sectional study, 35 preperimetric glaucoma eyes (32 subjects) and 94 control eyes (74 subjects) underwent digital optic disc photography and RNFL imaging with SDOCT and GDx ECC. Ability of RNFL parameters of SDOCT and GDx ECC to discriminate preperimetric glaucoma eyes from control eyes was compared using area under receiver operating characteristic curves (AUC), sensitivities at fixed specificities and likelihood ratios (LR). AUC of the global average RNFL thickness of SDOCT (0.786) was significantly greater (p<0.001) than that of GDx ECC (0.627). Sensitivities at 95% specificity of the corresponding parameters were 20% and 8.6% respectively. AUCs of the inferior, superior and temporal quadrant RNFL thickness parameters of SDOCT were also significantly (p<0.05) greater than the respective RNFL parameters of GDx ECC. LRs of outside normal limits category of SDOCT parameters ranged between 3.3 and 4.0 while the same of GDx ECC parameters ranged between 1.2 and 2.1. LRs of within normal limits category of SDOCT parameters ranged between 0.4 and 0.7 while the same of GDx ECC parameters ranged between 0.7 and 1.0. Abilities of the RNFL parameters of SDOCT and GDx ECC to diagnose preperimetric glaucoma were only moderate. Diagnostic abilities of the RNFL parameters of SDOCT were significantly better than that of GDx ECC in preperimetric glaucoma.

  6. Detection of Progressive Retinal Nerve Fiber Layer Loss in Glaucoma Using Scanning Laser Polarimetry with Variable Corneal Compensation

    Science.gov (United States)

    Medeiros, Felipe A.; Alencar, Luciana M.; Zangwill, Linda M.; Bowd, Christopher; Vizzeri, Gianmarco; Sample, Pamela A.; Weinreb, Robert N.

    2010-01-01

    Purpose To evaluate the ability of scanning laser polarimetry with variable corneal compensation to detect progressive retinal nerve fiber layer (RNFL) loss in glaucoma patients and patients suspected of having the disease. Methods This was an observational cohort study that included 335 eyes of 195 patients. Images were obtained annually with the GDx VCC scanning laser polarimeter, along with optic disc stereophotographs and standard automated perimetry (SAP) visual fields. The median follow-up time was 3.94 years. Progression was determined using commercial software for SAP and by masked assessment of optic disc stereophotographs performed by expert graders. Random coefficient models were used to evaluate the relationship between RNFL thickness measurements over time and progression as determined by SAP and/or stereophotographs. Results From the 335 eyes, 34 (10%) showed progression over time by stereophotographs and/or SAP. Average GDx VCC measurements decreased significantly over time for both progressors as well as non-progressors. However, the rate of decline was significantly higher in the progressing group (−0.70 μm/year) compared to the non-progressing group (−0.14 μm/year; P = 0.001). Black race and male sex were significantly associated with higher rates of RNFL loss during follow-up. Conclusions The GDx VCC scanning laser polarimeter was able to identify longitudinal RNFL loss in eyes that showed progression in optic disc stereophotographs and/or visual fields. These findings suggest that this technology could be useful to detect and monitor progressive disease in patients with established diagnosis of glaucoma or suspected of having the disease. PMID:19029038

  7. Glaucoma progression detection by retinal nerve fiber layer measurement using scanning laser polarimetry: event and trend analysis.

    Science.gov (United States)

    Moon, Byung Gil; Sung, Kyung Rim; Cho, Jung Woo; Kang, Sung Yong; Yun, Sung-Cheol; Na, Jung Hwa; Lee, Youngrok; Kook, Michael S

    2012-06-01

    To evaluate the use of scanning laser polarimetry (SLP, GDx VCC) to measure the retinal nerve fiber layer (RNFL) thickness in order to evaluate the progression of glaucoma. Test-retest measurement variability was determined in 47 glaucomatous eyes. One eye each from 152 glaucomatous patients with at least 4 years of follow-up was enrolled. Visual field (VF) loss progression was determined by both event analysis (EA, Humphrey guided progression analysis) and trend analysis (TA, linear regression analysis of the visual field index). SLP progression was defined as a reduction of RNFL exceeding the predetermined repeatability coefficient in three consecutive exams, as compared to the baseline measure (EA). The slope of RNFL thickness change over time was determined by linear regression analysis (TA). Twenty-two eyes (14.5%) progressed according to the VF EA, 16 (10.5%) by VF TA, 37 (24.3%) by SLP EA and 19 (12.5%) by SLP TA. Agreement between VF and SLP progression was poor in both EA and TA (VF EA vs. SLP EA, k = 0.110; VF TA vs. SLP TA, k = 0.129). The mean (±standard deviation) progression rate of RNFL thickness as measured by SLP TA did not significantly differ between VF EA progressors and non-progressors (-0.224 ± 0.148 µm/yr vs. -0.218 ± 0.151 µm/yr, p = 0.874). SLP TA and EA showed similar levels of sensitivity when VF progression was considered as the reference standard. RNFL thickness as measurement by SLP was shown to be capable of detecting glaucoma progression. Both EA and TA of SLP showed poor agreement with VF outcomes in detecting glaucoma progression.

  8. Abnormal retinal nerve fiber layer thickness and macula lutea in patients with mild cognitive impairment and Alzheimer's disease.

    Science.gov (United States)

    Gao, LiYan; Liu, Ying; Li, XiaoHong; Bai, QuanHao; Liu, Ping

    2015-01-01

    We investigated possible abnormalities in the retinal nerve fiber layer (RNFL) and macula lutea of patients diagnosed with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and tested for any correlation with the severity of dementia. A total of 72 subjects, comprising 25 AD patients, 26 MCI patients and 21 healthy individuals (controls) were enrolled in this study. The thickness of the RNFL and volume of the macula lutea was determined using optical coherence tomography (OCT). When compared with controls, we found statistically significant thinning of the RNFL in AD patients at all clock-hour positions except 12:00, and nasal quadrant, 2:00, 3:00 and 4:00. After adjusting several risk factors, the average thickness of the RNFL was reduced in MCI patients compared to AD patients, with specific reductions at inferior quadrant, 5:00 and 6:00. Compared to controls, MCI patients showed a significant decrease in RNFL thickness only in the temporal quadrant, 8:00, 9:00 and 10:00. We found significant reduction in the volume of the macula lutea both in AD and MCI patients. Finally, we could not establish any correlation between patient Mini-Mental State Examination (MMSE) scores (an estimation of the severity of cognitive impairment) and any OCT parameter. Retinal degeneration in AD and MCI patients results in decreased thickness of the RNFL, and reduced macular volume in AD and MCI patients. However, there seems to be no correlation between these changes and the severity of dementia. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  9. Pattern Visual Evoked Potential, Pattern Electroretinogram, and Retinal Nerve Fiber Layer Thickness in Patients with Migraine during and after Aura.

    Science.gov (United States)

    El-Shazly, Amany Abd El-Fattah; Farweez, Yousra Ahmed; Hamdi, Momen Mahmoud; El-Sherbiny, Noha Ezzat

    2017-09-01

    To study pattern visual evoked potential (PVEP), pattern electroretinogram (PERG), and retinal nerve fiber layer (RNFL) thickness in patients with migraine during and after aura. We included 60 eyes of 60 patients with migraine (Group 1) and 30 healthy volunteers (30 eyes) as controls (Group 2). Group 1 was studied twice, during a visual aura (1-a) and in between attacks (1-b). All participants underwent full ophthalmological examination, PVEP, PERG, and optical coherence tomographyOCT imaging of the RNFL thickness for each patient. RNFL thickness was found to be thinner in patients during the aura compared to controls. It increased significantly post-aura but remained lower than the controls. Prolonged P100 latency and decreased amplitude were found in patients during aura compared to controls with significant change in between attacks to values comparable to the controls. We found prolonged N95 latency and decreased amplitude in patients during aura compared to controls with significant change post-aura to values comparable to the controls. There was positive correlation between average RNFL thicknesses and VA and spherical equivalent; but it showed negative correlation with duration of migraine, attack duration, and aura duration. Multiple regression analysis showed that the most important determinants of average RNFL thickness in patients of migraine were attack and aura duration (beta = -0.21 and -0.26 and p = 0.03 and 0.04, respectively). Migraine attacks impose both functional and structural retinal changes. The functional changes are fully reversible after the aura but not the structural ones. So, vigorous prevention of migraine attacks would be protective for retina.

  10. Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome:one year follow-up results

    Directory of Open Access Journals (Sweden)

    Mehmet Ozgur Zengin

    2014-08-01

    Full Text Available AIM:To investigate the retinal nerve fiber layer (RNFL thickness changes in patients with obstructive sleep apnea syndrome (OSAS for one year follow-up. To discuss the possibility of detecting tendency of glaucoma in this population by using spectral domain optical coherence tomography (3D-OCT-2000 Spectral domain.METHODS:After polysomnographic study, all subjects (64 OSAS patients and 40 controls underwent detailed ophthalmological examination. After these examinations, patients with glaucoma and patients who had ophthalmological and/or systemic disease were excluded from the study. Totally, 20 patients in OSAS group and five patients in controls were excluded from the study in the first examination and follow-up period. The RNFL thickness was assessed with OCT. Forty-four OSAS patients and 35 control subjects were followed up 12mo. RNFL thickness change and OSAS patients were evaluated for severity of disease by Apnea-Hypopnea Index (AHI.RESULTS:Forty-four OSAS patients and 35 controls were enrolled in the study. Statistically significance was found between OSAS patients and controls at the 12th mo. Average RNFL thickness was found to be significantly lower in last measurements in OSAS patients when compared with first measurements and control subjects (P<0.001, 0.002, respectively. There was a statistically significant correlation among AHI, and RNFL thickness (P<0.05.CONCLUSION:The results suggest that the patients with OSAS were related with a proportional decrease in the RNFL thickness. These patients should be followed up regularly for glaucomatous changes. Detecting more RNFL thinning in severe OSAS was important.

  11. OCT Glaucoma Staging System: a new method for retinal nerve fiber layer damage classification using spectral-domain OCT.

    Science.gov (United States)

    Brusini, P

    2018-01-01

    PurposeTo describe a new method, the Optical Coherence Tomography (OCT) Glaucoma Staging System, for classifying retinal nerve fiber layer (RNFL) damage assessed with OCT.Patients and methodsThe OCT Glaucoma Staging System was created based on data obtained from Nidek RS 3000 spectral-domain (sd)-OCT. This system uses the superior and inferior quadrant RNFL thickness values, plotted on an x-y diagram for staging structural damage severity in glaucoma. A non-linear equation and two regression lines describe the boundary lines which separate the different sectors of the diagram. These mathematical formulas have been used to create a software, which provides a quick classification of the RNFL damage. Sensitivity and specificity of the system were assessed in a different cohort including 64 patients with early OAG, and 62 normal subjects.ResultsThree hundred and two OCT tests from 98 healthy controls and 284 patients affected by either ocular hypertension or chronic open-angle glaucoma were considered in order to design the new classification system. The OCT Glaucoma Staging System classifies RNFL defects into 6 stages of increasing severity ranging from borderline to stage 5, and 3 groups according to defect localization (superior, inferior, or diffuse). Sensitivity and specificity in discriminating between healthy and glaucomatous eyes were 95.2 and 91.9%, respectively, considering borderline results as abnormal.ConclusionsThe OCT Glaucoma Staging System appears to provide a standardized and objective classification of glaucomatous RNFL damage. It can be used in day-to-day clinical practice for an easy and fast interpretation of RNFL measurements obtained with OCT.

  12. Structural parameters associated with location of peaks of peripapillary retinal nerve fiber layer thickness in young healthy eyes.

    Directory of Open Access Journals (Sweden)

    Takehiro Yamashita

    Full Text Available The location of the peaks of the circumpapillary retinal nerve fiber layer (cpRNFL thickness is affected by several ocular parameters. In this study, we have generated equations that can determine the peaks of the cpRNFL. This study was a prospective, observational, cross sectional study of 118 healthy right eyes. The axial length, optic disc tilt, superiortemporal (ST- and inferiortemporal (IT-peaks of the cpRNFL thickness, and angles of the ST and IT retinal arteries (RA and veins (RV were determined. The correlations between the location of the ST- and IT-peaks and ocular structural parameters and the sex, body height and weight were calculated. The best fit equations to generate the location of the ST/IT-peaks were determined using corrected-Akaike Information Criteria. The location of the ST-peak was 0.72+(0.40 x ST-RA+(0.27 x ST-RV+(0.14 x height-(0.47 x papillo-macular-position-(0.11 x disc tilt with a coefficient of correlation of 0.61 (P<0.0001. The location of the IT-peak was 21.88+(0.53 x IT-RA+(0.15 x IT-RV+(0.041 x corneal thickness-(1.00 x axial length with a coefficient of correlation of 0.59 (P<0.0001. The location of ST/IT peaks is determined by different parameters of the ocular structure. These equations allow clinicians to obtain an accurate location of the peaks for a more accurate diagnosis of glaucoma.

  13. Optic Disc and Retinal Nerve Fiber Layer Thickness Evaluation of the Fellow Eyes in Non-Arteritic Ischemic Optic Neuropathy

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    Medine Yılmaz Dağ

    2015-05-01

    Full Text Available Objectives: To examine the fellow eyes in unilateral non-arteritic ischemic optic neuropathy (NAION and to compare their optic disc parameters and peripapillary retinal nerve fiber layer (RNFL thickness with age-and refraction-matched normal controll subjects, using Heidelberg Retinal Tomograph 2 (HRT II. Materials and Methods: The fellow eyes of 40 patients with typical unilateral NAION (study group and one randomly chosen eye of 42 age-, sex-, and refraction-matched normal control subjects were enrolled in the study. Optic disc morphologic features (average disc area, cup area, rim area, disc volume, rim volume, cup/disc area ratio, cup depth and peripapillary RNFL thickness were evaluated using HRT II, a confoal scanning ophtalmoscopy. Results: In the study group, there were 26 (65% men and 14 (35% women, whereas there were 27 (64% men and 15 (36% women in the control group (Chi square test, p=0.89. Mean age of the patients in the study and control groups was 59.4±10.3 and 57.7±9.1 years, respectively (T test, p=0.72. There was not any statistically significant difference regarding mean spheric equivalent between the two groups (Mann-Whitney U-test, p=0.203. The NAION unaffected fellow eyes had significantly smaller disc areas, cup areas, cup volumes, cup-disc area ratios (vertical and lineer, and cup depths than the control eyes (Mann-Whitney U-test; p<0.05, whereas there was no significant difference in the RNFL thickness between the two. Conclusion: A comparison of the fellow eyes in patients with unilateral NAION and the control eyes showed a significant difference in optic disc parameters and the morphology of RNFL. These differences could be important in the pathogenesis of NAION and needs to have further investigated. (Turk J Ophthalmol 2015; 45: 111-114

  14. Evaluation of retinal nerve fiber layer thickness in vernal keratoconjunctivitis patients under long-term topical corticosteroid therapy.

    Science.gov (United States)

    Cingu, Abdullah Kursat; Cinar, Yasin; Turkcu, Fatih Mehmet; Sahinoglu-Keskek, Nedime; Sahin, Alparslan; Sahin, Muhammed; Yuksel, Harun; Caca, Ihsan

    2014-09-01

    The aim of this study was to evaluate the retinal nerve fiber layer (RNFL) thickness in vernal keratoconjunctivitis (VKC) patients who were under long-term topical corticosteroid therapy. Thirty-six eyes of 36 VKC patients with clear cornea and normal videokeratography and 40 eyes of 40 age- and gender-matched normal children were included in the study. Clinical and demographic characteristics of the patients were noted and detailed ophthalmological examination was performed. Visual acuity (VA), spherical equivalent (SE), axial length (AL) and RNFL thickness measurements were compared between the groups. To correct ocular magnification effect on RNFL, we used Littmann's formula. All VKC patients had history of topical corticosteroid use and the mean duration of the topical corticosteroid use was 23.8 ± 9.09 months. There was no significant difference between the groups in terms of intraocular pressure (IOP). VKC group had significantly worse VA, greater SE and AL and thinner mean global, superior and inferior RNFL thickness. There were significant negative correlations between the duration of topical corticosteroid use and the mean global, superior and temporal RNFL thickness in VKC group. After correction of magnification effect, VKC group still had thinner mean global, superior and inferior RNFL thickness, and significant difference between the groups in inferior RNFL thickness did not disappear. Significant RNFL thickness difference between the groups suggests a possible effect of long-term corticosteroid use in VKC patients. Because visual field (VF) analysis in pediatric patients is difficult to perform and IOP may be illusive, RNFL thickness measurements in addition to routine examinations in VKC patients may help clinicians in their practice.

  15. Peripapillary Retinal Nerve Fiber Measurement with Spectral-Domain Optical Coherence Tomography in Age-Related Macular Degeneration

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    Simon K. Law

    2017-12-01

    Full Text Available Purpose: To evaluate the relationship between the peripapillary retinal nerve fiber layer (RNFL measurements with Spectral-domain Optical Coherence Tomography (OCT and Age-related macular degeneration (AMD. Methods: Patients >60 years of age without glaucoma or record of intraocular pressure >21 mmHg and no systemic or intraocular diseases or treatment or surgical intervention that affected the RNFL underwent OCT measurement of the RNFL. The severity of AMD was staged with the Clinical Age-Related Maculopathy Staging System. The relationship between RNFL measurements and AMD stages of one eye per patient was analyzed. Results: Eighty-six eyes (46 patients with AMD and no glaucoma or other exclusion criteria received OCT RNFL measurements. Nine eyes (10.5% were excluded because of distorted peripapillary anatomy from exudative AMD (7 eyes or failure of the RNFL segmentation algorithm (2 eyes. Mean age ± S.D. of the 43 patients analyzed was 81.2 ± 7.3 years. The mean stage ± S.D. of AMD of the 77 eyes was 3.77 ± 1.05. Higher stages of AMD were statistically significantly associated with lower average RNFL and inferior sector RNFL (p = 0.049, 0 0015, respectively. The association of inferior sector RNFL and AMD stage remained statistically significant after adjusting for age. Conclusions: Spectral domain OCT is generally useful in measuring the peripapillary RNFL in eyes with different stages of AMD. Higher stage of AMD is associated with thinner peripapillary RNFL, which may masquerade as early glaucomatous damage.

  16. Automated detection of nerve fiber layer defects on retinal fundus images using fully convolutional network for early diagnosis of glaucoma

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    Watanabe, Ryusuke; Muramatsu, Chisako; Ishida, Kyoko; Sawada, Akira; Hatanaka, Yuji; Yamamoto, Tetsuya; Fujita, Hiroshi

    2017-03-01

    Early detection of glaucoma is important to slow down progression of the disease and to prevent total vision loss. We have been studying an automated scheme for detection of a retinal nerve fiber layer defect (NFLD), which is one of the earliest signs of glaucoma on retinal fundus images. In our previous study, we proposed a multi-step detection scheme which consists of Gabor filtering, clustering and adaptive thresholding. The problems of the previous method were that the number of false positives (FPs) was still large and that the method included too many rules. In attempt to solve these problems, we investigated the end-to-end learning system without pre-specified features. A deep convolutional neural network (DCNN) with deconvolutional layers was trained to detect NFLD regions. In this preliminary investigation, we investigated effective ways of preparing the input images and compared the detection results. The optimal result was then compared with the result obtained by the previous method. DCNN training was carried out using original images of abnormal cases, original images of both normal and abnormal cases, ellipse-based polar transformed images, and transformed half images. The result showed that use of both normal and abnormal cases increased the sensitivity as well as the number of FPs. Although NFLDs are visualized with the highest contrast in green plane, the use of color images provided higher sensitivity than the use of green image only. The free response receiver operating characteristic curve using the transformed color images, which was the best among seven different sets studied, was comparable to that of the previous method. Use of DCNN has a potential to improve the generalizability of automated detection method of NFLDs and may be useful in assisting glaucoma diagnosis on retinal fundus images.

  17. Thickness, phase retardation, birefringence, and reflectance of the retinal nerve fiber layer in normal and glaucomatous non-human primates.

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    Dwelle, Jordan; Liu, Shuang; Wang, Bingqing; McElroy, Austin; Ho, Derek; Markey, Mia K; Milner, Thomas; Rylander, H Grady

    2012-07-01

    We identified candidate optical coherence tomography (OCT) markers for early glaucoma diagnosis. Time variation of retinal nerve fiber layer (RNFL) thickness, phase retardation, birefringence, and reflectance using polarization sensitive optical coherence tomography (PS-OCT) were measured in three non-human primates with induced glaucoma in one eye. We characterized time variation of RNFL thickness, phase retardation, birefringence, and reflectance with elevated intraocular pressure (IOP). One eye of each of three non-human primates was laser treated to increase IOP. Each primate was followed for a 30-week period. PS-OCT measurements were recorded at weekly intervals. Reflectance index (RI) is introduced to characterize RNFL reflectance. Associations between elevated IOP and RNFL thickness, phase retardation, birefringence, and reflectance were characterized in seven regions (entire retina, inner and outer rings, and nasal, temporal, superior and inferior quadrants) by linear and non-linear mixed-effects models. Elevated IOP was achieved in three non-human primate eyes with an average increase of 13 mm Hg over the study period. Elevated IOP was associated with decreased RNFL thickness in the nasal region (P = 0.0002), decreased RNFL phase retardation in the superior (P = 0.046) and inferior (P = 0.021) regions, decreased RNFL birefringence in the nasal (P = 0.002) and inferior (P = 0.029) regions, and loss of RNFL reflectance in the outer rings (P = 0.018). When averaged over the entire retinal area, only RNFL reflectance showed a significant decrease (P = 0.028). Of the measured parameters, decreased RNFL reflectance was the most robust correlate with glaucomatous damage. Candidate cellular mechanisms are considered for decreased RNFL reflectance, including mitochondrial dysfunction and retinal ganglion cell apoptosis.

  18. Whole Grains Contribute Only a Small Proportion of Dietary Fiber to the U.S. Diet.

    Science.gov (United States)

    Kranz, Sibylle; Dodd, Kevin W; Juan, Wen Yen; Johnson, LuAnn K; Jahns, Lisa

    2017-02-17

    Dietary fiber (DF), found in whole fruits, vegetables, and whole grains (WG), is considered a nutrient of concern in the US diet and increased consumption is recommended. The present study was designed to highlight this critical importance of the difference between WG, high-fiber WG, and sources of fiber that are not from WG. The study is based on the two-day diets reported consumed by the nationally representative sample of Americans participating in What We Eat In America, the dietary component of the National Health and Nutrition Examination Survey from 2003-2010. Foods consumed were classified into tertiles of DF and WG and the contribution of fiber by differing levels of WG content were examined. Foods containing high amounts of WG and DF only contributed about 7% of total fiber intake. Overall, grain-based foods contributed 54.5% of all DF consumed. Approximately 39% of DF came from grain foods that contained no WG, rather these foods contained refined grains, which contain only small amounts of DF but are consumed in large quantities. All WG-containing foods combined contributed a total of 15.3% of DF in the American diet. Thus, public health messaging needs to be changed to specifically encourage consumption of WG foods with high levels of DF to address both recommendations.

  19. Whole Grains Contribute Only a Small Proportion of Dietary Fiber to the U.S. Diet

    Directory of Open Access Journals (Sweden)

    Sibylle Kranz

    2017-02-01

    Full Text Available Dietary fiber (DF, found in whole fruits, vegetables, and whole grains (WG, is considered a nutrient of concern in the US diet and increased consumption is recommended. The present study was designed to highlight this critical importance of the difference between WG, high-fiber WG, and sources of fiber that are not from WG. The study is based on the two-day diets reported consumed by the nationally representative sample of Americans participating in What We Eat In America, the dietary component of the National Health and Nutrition Examination Survey from 2003–2010. Foods consumed were classified into tertiles of DF and WG and the contribution of fiber by differing levels of WG content were examined. Foods containing high amounts of WG and DF only contributed about 7% of total fiber intake. Overall, grain-based foods contributed 54.5% of all DF consumed. Approximately 39% of DF came from grain foods that contained no WG, rather these foods contained refined grains, which contain only small amounts of DF but are consumed in large quantities. All WG-containing foods combined contributed a total of 15.3% of DF in the American diet. Thus, public health messaging needs to be changed to specifically encourage consumption of WG foods with high levels of DF to address both recommendations.

  20. Characterization of Esthetic Orthodontic Wires Made from Glass-Fiber-Reinforced Thermoplastic Containing High-Strength, Small-Diameter Glass Fibers

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    Yasuhiro Tanimoto

    2018-01-01

    Full Text Available In this work, we investigated the properties of a glass-fiber-reinforced thermoplastic (GFRTP composed of small-diameter (ϕ = 5 μm, high-strength glass (T-glass fibers and polycarbonate for esthetic orthodontic wires formed using pultrusion. After fabricating such GFRTP round wires, the effects of varying fiber diameter (5 to 13 mm on the mechanical properties, durabilities, and color stabilities were evaluated. The results showed that the mechanical properties of GFRTPs tend to increase with decreasing fiber diameter. Additionally, it was confirmed that the present GFRTP wires containing T-glass fibers have better flexural properties than previously reported GFRTP wires containing E-glass fibers. Meanwhile, thermocycling did not significantly affect the flexural properties of the GFRTP wires. Furthermore, the GFRTP wires showed color changes lower than the acceptable threshold level for color differences on immersion in coffee. From these results obtained in the present work, the GFRTP wires containing high-strength glass fibers have excellent properties for orthodontic applications. Our findings suggest that the GFRTPs might be applied to all phases of orthodontic treatment because their properties can be tuned by changing the fiber properties such as fiber type and diameter.

  1. Auditory nerve fiber representation of cues to voicing in syllable-final stop consonants

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    Sinex, D.G. (Boys Town National Research Hospital, Omaha, NE (United States))

    1993-09-01

    Acoustic cues to the identity of consonants such as d and t vary according to contextual factors such as the position of the consonant within a syllable. However, investigations of the neural coding of consonants have almost always used stimuli in which the consonant occurs in the syllable-initial position. The present experiments examined the peripheral neural representation of spectral and temporal cues that can distinguish between stop consonants d and t in syllable-final position. Stimulus sets consisting of the syllables hid, hit, hud, and hut were recorded by three different talkers. During the consonant closure interval, the spectrum of d was characterized by the presence of a low-frequency voice bar. Most neurons responses were characterized by discharge rate decreases at the beginning of the closure interval and by rate increases that marked the release of the consonant closure. Exceptions were seen in the responses of neurons with characteristics frequencies (CFs) below approximately 0.7 kHz to syllables ending in d. These neurons responded to the voice bar with discharge rates that could approach the rates elicited by the vowel. The latencies of prominent discharge rate changes were measured for all neurons and used to compute the length of the encoded closure interval. The encoded interval was clearly longer for syllables ending in t than in d. The encoded interval increased with CF for both consonants but more rapidly for t. Differences in the encoded closure interval were small for syllables with different vowels or syllables produced by different talkers. 29 refs., 10 figs.

  2. Candesartan prevents resiniferatoxin-induced sensory small-fiber neuropathy in mice by promoting angiotensin II-mediated AT2 receptor stimulation.

    Science.gov (United States)

    Bessaguet, Flavien; Danigo, Aurore; Magy, Laurent; Sturtz, Franck; Desmoulière, Alexis; Demiot, Claire

    2017-11-01

    Sensory defects associated with small-fiber neuropathy (SFN) can lead to profound disabilities. The relationship between the sensory nervous system and modulation of the renin-angiotensin system (RAS) has been described and focused on pain and neurodegeneration in several animal models. We have recently developed an experimental model of functional sensory neuropathy showing thermal hypoalgesia and neuropeptide depletion without nerve fiber degeneration. Here, we aimed to determine whether the modulation of angiotensin II (Ang II) activity could prevent sensory neuropathy induced by RTX. Control and RTX mice received ramipril, an Ang II converting enzyme (ACE) inhibitor, (0.5 mg/kg/day) or candesartan, an Ang II type 1 receptor (AT1R) blocker (0.5 mg/kg/day), one day before vehicle or RTX administration, and each day for the next seven days. Ramipril did not have a beneficial effect in RTX mice, whereas candesartan prevented thermal hypoalgesia and reduced neuropeptide depletion in intraepidermal nerve fibers and dorsal root ganglion neurons. The preventive effect of candesartan was not observed in mice deficient for the Ang II type 2 receptor (AT2R) and was counteracted in wild type mice by EMA200, an AT2R antagonist (3 mg/kg/day). Thus, candesartan may promote AT2R activation by blocking AT1R and increasing Ang II production and enhance its mechanisms of neuroprotection in our RTX model. Our finding that candesartan prevents nociception deficits and neuropeptide depletion encourages the evaluation of its therapeutic potential in patients presenting SFN, particularly those who experience chemotherapy-induced SFN. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Macular Ganglion Cell and Retinal Nerve Fiber Layer Thickness in Children With Refractive Errors-An Optical Coherence Tomography Study.

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    Goh, Jody P; Koh, Victor; Chan, Yiong Huak; Ngo, Cheryl

    2017-07-01

    To study the distribution of macular ganglion cell-inner plexiform layer (GC-IPL) thickness and peripapillary retinal nerve fiber layer (RNFL) thickness in children with refractive errors. Two hundred forty-three healthy eyes from 139 children with refractive error ranging from -10.00 to +5.00 D were recruited from the National University Hospital Eye Surgery outpatient clinic. After a comprehensive ocular examination, refraction, and axial length (AL) measurement (IOLMaster), macular GC-IPL and RNFL thickness values were obtained with a spectral domain Cirrus high definition optical coherence tomography system (Carl Zeiss Meditec Inc.). Only scans with signal strength of >6/10 were included. Correlation between variables was calculated using the Pearson correlation coefficient. A multivariate analysis using mixed models was done to adjust for confounders. The mean spherical equivalent refraction was -3.20±3.51 D and mean AL was 24.39±1.72 mm. Average, minimum, superior, and inferior GC-IPL were 82.59±6.29, 77.17±9.65, 83.68±6.96, and 81.64±6.70 μm, respectively. Average, superior, and inferior peripapillary RNFL were 99.00±11.45, 123.20±25.81, and 124.24±22.23 μm, respectively. Average, superior, and inferior GC-IPL were correlated with AL (β=-2.056, P-value 0.000; β=-2.383, P-value 0.000; β=-1.721, P-value 0.000), but minimum GC-IPL was not (β=-1.056, P-value 0.115). None of the RNFL parameters were correlated with AL. This study establishes normative macular GC-IPL and RNFL thickness in children with refractive errors. Our results suggest that high definition optical coherence tomography RNFL parameters and minimum GC-IPL are not affected by AL or myopia in children, and therefore warrants further evaluation in pediatric glaucoma patients.

  4. Correlation between Retinal Nerve Fiber Layer Thickness by Optical Coherence Tomography and Perimetric Parameters in Optic Atrophy

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    Mostafa Soltan-Sanjari

    2008-12-01

    Full Text Available

    PURPOSE: To investigate the correlation between retinal nerve fiber layer (RNFL thickness determined by optical coherence tomography (OCT and visual field (VF parameters in patients with optic atrophy. METHODS: This study was performed on 35 eyes of 28 patients with optic atrophy. RNFL thickness was measured by OCT (Carl Zeiss, Jena, Germany and automated perimetry was performed using the Humphrey Field Analyzer (Carl Zeiss, Jena, Germany. The correlation between RNFL thickness and VF parameters was evaluated. RESULTS: Mean global RNFL thickness was 44.9±27.5 µm which was significantly correlated with mean deviation score on automated perimetry (r=0.493, P=0.003; however, no significant correlation was observed between visual field pattern standard deviation and the corresponding quadrantic RNFL thickness. In a similar manner, no significant association was found between visual acuity and RNLF thickness. CONCLUSION: Mean global RNFL thickness as determined by OCT seems to be correlated with VF defect depth as represented by the mean deviation score on Humphrey VF testing. OCT may be used as an objective diagnostic tool in the evaluation of patients with optic atrophy.

  5. Alterations in retinal nerve fiber layer thickness in early stages of diabetic retinopathy and potential risk factors.

    Science.gov (United States)

    Shi, Rui; Guo, Zhonglan; Wang, Feng; Li, Rong; Zhao, Lei; Lin, Rong

    2018-02-01

    To investigate the loss of retinal nerve fiber layer (RNFL) in type-2 diabetic patients with early-stage diabetic retinopathy (DR) and to identify potential risk factors accounting for these alterations. In this cross-sectional study, 158 type-2 diabetic patients were divided into three groups based on their DR status. RNFL thickness and other optic disc parameters were obtained by optical coherence tomography (OCT) and then compared among different groups. We investigated the potential association between RNFL loss and systemic risk factors for DR, including diabetes duration, body mass index (BMI), serum lipids, hemoglobin A1c (HbA1c) and albumin-creatinine ratio (ACR). One-way ANOVA was carried out to compare RNFL thickness among different groups, Pearson correlation and multivariate linear regression analysis were performed to determine potential risk factors related to RNFL thickness in these patients. There were significant differences in the average (F = 8.872, P = 0.003), superior (F = 8.769, P = 0.004), and inferior (F = 8.857, P = 0.003) RNFL thickness of both eyes among the groups, but no obvious difference in optic disc parameters was found. Diabetic duration, BMI, TG, High density lipoprotein cholesterol (HDL), HbA1c, and ACR were found negatively related to the RNFL thickness in both or single eye according to Pearson correlation analysis. After controlling for age, gender, and axis length (AL) in multivariate linear regression analysis, the diabetic duration was associated significantly with RNFL thickness of superior in both eye (right eye: p = 0.016, left eye: p = 0.024), BMI was related to the nasal quadrant of the right eye (p = 0.034), and TG was related to the inferior of the right eye (p = 0.037), HbA1c (p = 0.026) was associated significantly with the average RNFL thickness of the right eye. In addition, ACR was found negatively related to average (p = 0.042) and inferior quadrant (p = 0.014) of the left eye

  6. Effects of serum albumin on SPR-measured affinity of small molecule inhibitors binding to nerve growth factor

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    Allison E. Kennedy

    2017-09-01

    Full Text Available The study of the interactions between a drug and plasma serum proteins are necessary in determining pharmacological and toxicological properties for therapeutic development. Small molecule nerve growth factor (NGF inhibitors have been investigated for their abilities to inhibit NGF binding to TrkA as a potential therapeutic option for the treatment of neuropathic and inflammatory pain. In this study, surface plasmon resonance (SPR spectroscopy and 125I-NGF radioisotope binding assays were carried out to better understand the role of serum albumin (SA in small molecule binding to NGF. SA has been characterized as a universal drug carrier with up to seven binding domains on its surface to transport drug molecules to target tissues. Here, we use SPR kinetic analysis to analyze the change in specificity of small molecules to immobilized NGF in the presence and absence of SA. In the presence of SA an overall increase in small molecule binding affinity for NGF was observed compared to binding in the absence of SA. Our results suggest a crucial role for SA in the pharmacokinetics of small molecule binding to NGF. This effect will require consideration when developing therapeutic agents.

  7. Morphological changes of cholinergic nerve fibers in the urinary bladder after establishment of artificial somatic-autonomic reflex arc in rats.

    Science.gov (United States)

    Wang, Han-Zhi; Li, Shu-Rong; Wen, Can; Xiao, Chuan-Guo; Su, Bing-Yin

    2007-09-01

    To establish an artificial somatic-autonomic reflex arc in rats and observe the following distributive changes of neural fibers in the bladder. Adult Sprague-Dawley rats were randomly divided into three groups: control group, spinal cord injury (SCI) group, and reinnervation group. DiI retrograde tracing was used to verify establishment of the model and to investigate the transport function of the regenerated efferent axons in the new reflex arc. Choline acetyltransferase (ChAT) in the DiI-labeled neurons was detected by immunohistochemistry. Distribution of neural fibers in the bladder was observed by acetylcholine esterase staining. DiI-labeled neurons distributed mainly in the left ventral horn from L3 to L5, and some of them were also ChAT-positive. The neural fibers in the bladder detrusor reduced remarkably in the SCI group compared with the control (P bladder increased markedly compared with the SCI group (P < 0.05), though still much less than that in the control (P < 0.05). The efferent branches of the somatic nerves may grow and replace the parasympathetic preganglionic axons through axonal regeneration. Acetylcholine is still the major neurotransmitter of the new reflex arc. The controllability of detrusor may be promoted when it is reinnervated by the pelvic ganglia efferent somatic motor fibers from the postganglionic axons.

  8. Induction of paranodal myelin detachment and sodium channel loss in vivo by Campylobacter jejuni DNA-binding protein from starved cells (C-Dps) in myelinated nerve fibers.

    Science.gov (United States)

    Piao, Hua; Minohara, Motozumi; Kawamura, Nobutoshi; Li, Wei; Mizunoe, Yoshimitsu; Umehara, Fujio; Goto, Yoshinobu; Kusunoki, Susumu; Matsushita, Takuya; Ikenaka, Kazuhiro; Maejima, Takashi; Nabekura, Jun-ichi; Yamasaki, Ryo; Kira, Jun-ichi

    2010-01-15

    Iba-1-positive macrophages were observed. Thus, we consider that C-Dps damages myelinated nerve fibers, possibly through interference with paranodal sulfatide function, and may contribute to the axonal pathology seen in C. jejuni-related GBS.

  9. Comparisons of Retinal Nerve Fiber Layer Thickness after Indocyanine Green, Brilliant Blue G, or Triamcinolone Acetonide-Assisted Macular Hole Surgery

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    Yoshiharu Toba

    2014-01-01

    Full Text Available Purpose. To compare the postoperative changes of the retinal nerve fiber layer (RNFL thickness in patients with macular holes (MHs treated with vitrectomy with indocyanine green- (ICG-, brilliant blue G- (BBG-, or triamcinolone acetonide- (TA-assisted internal limiting membrane (ILM peeling. Methods. Sixty-one eyes of 61 consecutive patients with MHs were studied. Each eye was randomly selected to undergo either ICG- (n=18, BBG- (n=21, or TA-assisted (n=22 ILM peeling. The circumferential retinal nerve fiber layer (RNFL thickness was determined by spectral-domain optical coherence tomography (SD-OCT before and 1, 3, 6, 9, and 12 months postoperatively. The mean overall and the sectoral thicknesses of the RNFL were obtained for each group. Results. A transient increase of the RNFL thickness was seen in the mean overall and sectoral thicknesses except for the nasal/inferior sector at 1 month after surgery for the three groups. Then, the thickness gradually decreased and returned to the baseline level in all sectors except for the nasal/inferior sector. The differences in the RNFL thickness among the groups were not significant for at least 12 months postoperatively. Conclusions. The degree of change of the RNFL thickness was not significantly related to the type of vital stain used during MH surgery.

  10. Repeatability and Reproducibility of Retinal Nerve Fiber Layer Parameters Measured by Scanning Laser Polarimetry with Enhanced Corneal Compensation in Normal and Glaucomatous Eyes.

    Science.gov (United States)

    Ara, Mirian; Ferreras, Antonio; Pajarin, Ana B; Calvo, Pilar; Figus, Michele; Frezzotti, Paolo

    2015-01-01

    To assess the intrasession repeatability and intersession reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness parameters measured by scanning laser polarimetry (SLP) with enhanced corneal compensation (ECC) in healthy and glaucomatous eyes. One randomly selected eye of 82 healthy individuals and 60 glaucoma subjects was evaluated. Three scans were acquired during the first visit to evaluate intravisit repeatability. A different operator obtained two additional scans within 2 months after the first session to determine intervisit reproducibility. The intraclass correlation coefficient (ICC), coefficient of variation (COV), and test-retest variability (TRT) were calculated for all SLP parameters in both groups. ICCs ranged from 0.920 to 0.982 for intravisit measurements and from 0.910 to 0.978 for intervisit measurements. The temporal-superior-nasal-inferior-temporal (TSNIT) average was the highest (0.967 and 0.946) in normal eyes, while nerve fiber indicator (NFI; 0.982) and inferior average (0.978) yielded the best ICC in glaucomatous eyes for intravisit and intervisit measurements, respectively. All COVs were under 10% in both groups, except NFI. TSNIT average had the lowest COV (2.43%) in either type of measurement. Intervisit TRT ranged from 6.48 to 12.84. The reproducibility of peripapillary RNFL measurements obtained with SLP-ECC was excellent, indicating that SLP-ECC is sufficiently accurate for monitoring glaucoma progression.

  11. Polycystic Ovary Syndrome: Aggressive or Protective Factor for the Retina? Evaluation of Macular Thickness and Retinal Nerve Fiber Layers Using High-Definition Optical Coherence Tomography

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    José Edvan de Souza-Júnior

    2015-01-01

    Full Text Available Objective. To compare macular thickness (MT and retinal nerve fiber layers (RNFL between women with polycystic ovary syndrome (PCOS and healthy women. Materials and Methods. The study included 45 women with PCOS and 47 ovulatory women undergoing clinical-gynecological and ophthalmic evaluations, including measurement of MT, RNFL, and optic disc parameters using optical coherence tomography. Results. The superior RNFL around the optic nerve was significantly thicker in PCOS than in healthy volunteers (P=0.036. After stratification according to insulin resistance, the temporal inner macula (TIM, the inferior inner macula (IIM, the nasal inner macula (NIM, and the nasal outer macula (NOM were significantly thicker in PCOS group than in control group (P<0.05. Both the presence of obesity associated with insulin resistance (P=0.037 and glucose intolerance (P=0.001 were associated with significant increase in the PC1 mean score, relative to MT. A significant increase in the PC2 mean score occurred when considering the presence of metabolic syndrome (P<0.0001. There was a significant interaction between obesity and inflammation in a decreasing mean PC2 score relative to macular RNFL thickness (P=0.034. Conclusion. Decreased macular RNFL thickness and increased total MT are associated with metabolic abnormalities, while increased RNFL thickness around the optic nerve is associated with hormonal changes inherent in PCOS.

  12. Hypothesis: Human papillomavirus vaccination syndrome--small fiber neuropathy and dysautonomia could be its underlying pathogenesis.

    Science.gov (United States)

    Martínez-Lavín, Manuel

    2015-07-01

    Vaccination has been one of the most effective public health measures in the history of medicine. However, seemingly inexplicit adverse reactions have been described after the injection of the newer vaccines vs. human papillomavirus (HPV). The symptoms more often reported are chronic pain with paresthesias, headaches, fatigue, and orthostatic intolerance. Adverse reactions appear to be more frequent after HPV vaccination when compared to other type of immunizations. Different isolated cases and small series have described the development of complex regional pain syndrome (CRPS), postural orthostatic tachycardia syndrome (POTS), and fibromyalgia after HPV vaccination. These are illnesses often difficult to diagnose that have overlapping clinical features. Sympathetic nervous system dysfunction seems to play a major role in the pathogenesis of these syndromes. Also, small fiber neuropathy has been recently recognized in CRPS, POTS, and fibromyalgia. This article forwards the hypothesis that small fiber neuropathy and dysautonomia could be the common underlying pathogenesis to the group of rare, but severe reactions that follow HPV vaccination. Clinicians should be aware of the possible association between HPV vaccination and the development of these difficult to diagnose painful dysautonomic syndromes.

  13. Small RNA sequencing and degradome analysis of developing fibers of short fiber mutants Ligon-lintles-1 (Li 1 ) and -2 (Li 2 ) revealed a role for miRNAs and their targets in cotton fiber elongation.

    Science.gov (United States)

    Naoumkina, Marina; Thyssen, Gregory N; Fang, David D; Hinchliffe, Doug J; Florane, Christopher B; Jenkins, Johnie N

    2016-05-17

    The length of cotton fiber is an important agronomic trait that directly affects the quality of yarn and fabric. Understanding the molecular basis of fiber elongation would provide a means for improvement of fiber length. Ligon-lintless-1 (Li 1 ) and -2 (Li 2 ) are monogenic and dominant mutations that result in an extreme reduction in the length of lint fiber on mature seeds. In a near-isogenic state with wild type cotton these two short fiber mutants provide an effective model system to study the mechanisms of fiber elongation. Plant miRNAs regulate many aspects of growth and development. However, the mechanism underlying the miRNA-mediated regulation of fiber development is largely unknown. Small RNA libraries constructed from developing fiber cells of the short fiber mutants Li 1 and Li 2 and their near-isogenic wild type lines were sequenced. We identified 24 conservative and 147 novel miRNA families with targets that were detected through degradome sequencing. The distribution of the target genes into functional categories revealed the largest set of genes were transcription factors. Expression profiles of 20 miRNAs were examined across a fiber developmental time course in wild type and short fiber mutations. We conducted correlation analysis between miRNA transcript abundance and the length of fiber for 11 diverse Upland cotton lines. The expression patterns of 4 miRNAs revealed significant negative correlation with fiber lengths of 11 cotton lines. Our results suggested that the mutations have changed the regulation of miRNAs expression during fiber development. Further investigations of differentially expressed miRNAs in the Li 1 and Li 2 mutants will contribute to better understanding of the regulatory mechanisms of cotton fiber development. Four miRNAs negatively correlated with fiber length are good candidates for further investigations of miRNA regulation of important genotype dependent fiber traits. Thus, our results will contribute to further studies

  14. Large A-fiber activity is required for microglial proliferation and p38 MAPK activation in the spinal cord: different effects of resiniferatoxin and bupivacaine on spinal microglial changes after spared nerve injury

    Directory of Open Access Journals (Sweden)

    Decosterd Isabelle

    2009-09-01

    Full Text Available Abstract Background After peripheral nerve injury, spontaneous ectopic activity arising from the peripheral axons plays an important role in inducing central sensitization and neuropathic pain. Recent evidence indicates that activation of spinal cord microglia also contributes to the development of neuropathic pain. In particular, activation of p38 mitogen-activated protein kinase (MAPK in spinal microglia is required for the development of mechanical allodynia. However, activity-dependent activation of microglia after nerve injury has not been fully addressed. To determine whether spontaneous activity from C- or A-fibers is required for microglial activation, we used resiniferatoxin (RTX to block the conduction of transient receptor potential vanilloid subtype 1 (TRPV1 positive fibers (mostly C- and Aδ-fibers and bupivacaine microspheres to block all fibers of the sciatic nerve in rats before spared nerve injury (SNI, and observed spinal microglial changes 2 days later. Results SNI induced robust mechanical allodynia and p38 activation in spinal microglia. SNI also induced marked cell proliferation in the spinal cord, and all the proliferating cells (BrdU+ were microglia (Iba1+. Bupivacaine induced a complete sensory and motor blockade and also significantly inhibited p38 activation and microglial proliferation in the spinal cord. In contrast, and although it produced an efficient nociceptive block, RTX failed to inhibit p38 activation and microglial proliferation in the spinal cord. Conclusion (1 Blocking peripheral input in TRPV1-positive fibers (presumably C-fibers is not enough to prevent nerve injury-induced spinal microglial activation. (2 Peripheral input from large myelinated fibers is important for microglial activation. (3 Microglial activation is associated with mechanical allodynia.

  15. Surface Microstructures on Planar Substrates and Textile Fibers Guide Neurite Outgrowth: A Scaffold Solution to Push Limits of Critical Nerve Defect Regeneration?

    Science.gov (United States)

    Weigel, Stefan; Tobler, Ursina; Yao, Li; Wiesli, Manuel; Lehnert, Thomas; Pandit, Abhay; Bruinink, Arie

    2012-01-01

    The treatment of critical size peripheral nerve defects represents one of the most serious problems in neurosurgery. If the gap size exceeds a certain limit, healing can't be achieved. Connection mismatching may further reduce the clinical success. The present study investigates how far specific surface structures support neurite outgrowth and by that may represent one possibility to push distance limits that can be bridged. For this purpose, growth cone displacement of fluorescent embryonic chicken spinal cord neurons was monitored using time-lapse video. In a first series of experiments, parallel patterns of polyimide ridges of different geometry were created on planar silicon oxide surfaces. These channel-like structures were evaluated with and without amorphous hydrogenated carbon (a-C:H) coating. In a next step, structured and unstructured textile fibers were investigated. All planar surface materials (polyimide, silicon oxide and a-C:H) proved to be biocompatible, i.e. had no adverse effect on nerve cultures and supported neurite outgrowth. Mean growth cone migration velocity measured on 5 minute base was marginally affected by surface structuring. However, surface structure variability, i.e. ridge height, width and inter-ridge spacing, significantly enhanced the resulting net velocity by guiding the growth cone movement. Ridge height and inter-ridge distance affected the frequency of neurites crossing over ridges. Of the evaluated dimensions ridge height, width, and inter-ridge distance of respectively 3, 10, and 10 µm maximally supported net axon growth. Comparable artificial grooves, fabricated onto the surface of PET fibers by using an excimer laser, showed similar positive effects. Our data may help to further optimize surface characteristics of artificial nerve conduits and bioelectronic interfaces. PMID:23251379

  16. Surface microstructures on planar substrates and textile fibers guide neurite outgrowth: a scaffold solution to push limits of critical nerve defect regeneration?

    Directory of Open Access Journals (Sweden)

    Stefan Weigel

    Full Text Available The treatment of critical size peripheral nerve defects represents one of the most serious problems in neurosurgery. If the gap size exceeds a certain limit, healing can't be achieved. Connection mismatching may further reduce the clinical success. The present study investigates how far specific surface structures support neurite outgrowth and by that may represent one possibility to push distance limits that can be bridged. For this purpose, growth cone displacement of fluorescent embryonic chicken spinal cord neurons was monitored using time-lapse video. In a first series of experiments, parallel patterns of polyimide ridges of different geometry were created on planar silicon oxide surfaces. These channel-like structures were evaluated with and without amorphous hydrogenated carbon (a-C:H coating. In a next step, structured and unstructured textile fibers were investigated. All planar surface materials (polyimide, silicon oxide and a-C:H proved to be biocompatible, i.e. had no adverse effect on nerve cultures and supported neurite outgrowth. Mean growth cone migration velocity measured on 5 minute base was marginally affected by surface structuring. However, surface structure variability, i.e. ridge height, width and inter-ridge spacing, significantly enhanced the resulting net velocity by guiding the growth cone movement. Ridge height and inter-ridge distance affected the frequency of neurites crossing over ridges. Of the evaluated dimensions ridge height, width, and inter-ridge distance of respectively 3, 10, and 10 µm maximally supported net axon growth. Comparable artificial grooves, fabricated onto the surface of PET fibers by using an excimer laser, showed similar positive effects. Our data may help to further optimize surface characteristics of artificial nerve conduits and bioelectronic interfaces.

  17. Sound and vibration sensitivity of VIIIth nerve fibers in the frogs Leptodactylus albilabris and Rana pipiens pipiens

    DEFF Research Database (Denmark)

    Christensen-Dalsgaard, J; Narins, P M

    1993-01-01

    1. Responses of 73 fibers to dorso-ventral vibration were recorded in the saccular and utricular branchlets of Rana pipiens pipiens using a ventral approach. The saccular branchlet contained nearly exclusively vibration-sensitive fibers (33 out of 36) with best frequencies (BFs) between 10 and 70...

  18. Optic nerve hypoplasia

    Directory of Open Access Journals (Sweden)

    Savleen Kaur

    2013-01-01

    Full Text Available Optic nerve hypoplasia (ONH is a congenital anomaly of the optic disc that might result in moderate to severe vision loss in children. With a vast number of cases now being reported, the rarity of ONH is obviously now refuted. The major aspects of ophthalmic evaluation of an infant with possible ONH are visual assessment, fundus examination, and visual electrophysiology. Characteristically, the disc is small, there is a peripapillary double-ring sign, vascular tortuosity, and thinning of the nerve fiber layer. A patient with ONH should be assessed for presence of neurologic, radiologic, and endocrine associations. There may be maternal associations like premature births, fetal alcohol syndrome, maternal diabetes. Systemic associations in the child include endocrine abnormalities, developmental delay, cerebral palsy, and seizures. Besides the hypoplastic optic nerve and chiasm, neuroimaging shows abnormalities in ventricles or white- or gray-matter development, septo-optic dysplasia, hydrocephalus, and corpus callosum abnormalities. There is a greater incidence of clinical neurologic abnormalities in patients with bilateral ONH (65% than patients with unilateral ONH. We present a review on the available literature on the same to urge caution in our clinical practice when dealing with patients with ONH. Fundus photography, ocular coherence tomography, visual field testing, color vision evaluation, neuroimaging, endocrinology consultation with or without genetic testing are helpful in the diagnosis and management of ONH. (Method of search: MEDLINE, PUBMED.

  19. Size of the Optic Nerve Head and Its Relationship with the Thickness of the Macular Ganglion Cell Complex and Peripapillary Retinal Nerve Fiber Layer in Patients with Primary Open Angle Glaucoma

    Directory of Open Access Journals (Sweden)

    Nobuko Enomoto

    2015-01-01

    Full Text Available Purpose. To evaluate the relationships among the optic nerve head (ONH area, macular ganglion cell complex (mGCC thickness, circumpapillary retinal nerve fiber layer (cpRNFL thickness, and visual field defects in patients with primary open angle glaucoma (POAG. Methods. This retrospective study included 90 eyes of 90 patients with POAG. The ONH area, rim area, mGCC thickness, and cpRNFL thickness were measured using optical coherence tomography. Mean deviation (MD was measured using standard automated perimetry. The relationships among clinical factors including age, refraction, the ONH area, the rim area, the mGCC thickness, the cpRNFL thickness, and MD were evaluated using correlation coefficients and multiple regression analyses. Results. The significant correlation of the ONH area with refraction (r=0.362, P<0.001, the mGCC thickness (r=0.225, P=0.033, and the cpRNFL thickness (r=0.253, P=0.016 was found. Multiple regression analysis showed that the ONH area, rim area, and MD were selected as significant contributing factors to explain the mGCC thickness and cpRNFL thickness. No factor was selected to explain MD. Conclusions. The ONH area, in other words, the disc size itself may affect the mGCC thickness and cpRNFL thickness in POAG patients.

  20. Effect of pulsed infrared lasers on neural conduction and axoplasmic transport in sensory nerves

    Science.gov (United States)

    Wesselmann, Ursula; Rymer, William Z.; Lin, Shien-Fong

    1990-06-01

    Over the past ten years there has been an increasing interest in the use of lasers for neurosurgical and neurological procedures. Novel recent applications range from neurosurgical procedures such as dorsal root entry zone lesions made with argon and carbon dioxide microsurgical lasers to pain relief by low power laser irradiation of the appropriate painful nerve or affected region1 '2 However, despite the widespread clinical applications of laser light, very little is known about the photobiological interactions between laser light and nervous tissue. The present studies were designed to evaluate the effects of pulsed Nd:YAG laser light on neural impulse conduction and axoplasmic transport in sensory nerves in rats and cats. Our data indicate that Q-switched Nd:YAG laser irradiation can induce a preferential impairment of (1) the synaptic effects of small afferent fibers on dorsal horn cells in the spinal cord and of (2) small slow conducting sensory nerve fibers in dorsal roots and peripheral nerves. These results imply that laser light might have selective effects on impulse conduction in slow conducting sensory nerve fibers. In agreement with our elecirophysiological observations recent histological data from our laboratory show, that axonal transport of the enzyme horseradish peroxidase is selectively impaired in small sensory nerve fibers. In summary these data indicate, that Q-switched Nd:YAG laser irradiation can selectively impair neural conduction and axoplasmic transport in small sensory nerve fibers as compared to fast conducting fibers. A selective influence of laser irradiation on slow conducting fibers could have important clinical applications, especially for the treatment of chronic pain.

  1. Substance P restores normal skin architecture and reduces epidermal infiltration of sensory nerve fiber in TNCB-induced atopic dermatitis-like lesions in NC/Nga mice.

    Science.gov (United States)

    Choi, Hyeongwon; Kim, Dong-Jin; Nam, Seungwoo; Lim, Sunki; Hwang, Jae-Sung; Park, Ki Sook; Hong, Hyun Sook; Won, Younsun; Shin, Min Kyung; Chung, Eunkyung; Son, Youngsook

    2018-03-01

    Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by intense pruritus and eczematous lesion. Substance P (SP) is an 11-amino-acid endogenous neuropeptide that belongs to the tachykinin family and several reports recently have supported the anti-inflammatory and tissue repairing roles of SP. In this study, we investigated whether SP can improve AD symptoms, especially the impaired skin barrier function, in 2, 4, 6-trinitrochlorobenzene (TNCB)-induced chronic dermatitis of NC/Nga mice or not. AD-like dermatitis was induced in NC/Nga mice by repeated sensitization with TNCB for 5 weeks. The experimental group designations and topical treatments were as follows: vehicle group (AD-VE); SP group (AD-SP); and SP with NK1R antagonist CP99994 (AD-SP-A) group. Histological analysis was performed to evaluate epidermal differentiation, dermal integrity, and epidermal nerve innervation in AD-like lesions. The skin barrier functions and pruritus of NC/Nga mice were evaluated by measuring transepidermal water loss (TEWL) and scratching behavior, respectively. Topical SP treatment resulted in significant down-regulation of Ki67 and the abnormal-type keratins (K) K6, K16, and K17, restoration of filaggrin and claudin-1, marked reduction of TEWL, and restoration of basement membrane and dermal collagen deposition, even under continuous sensitization of low dose TNCB. In addition, SP significantly reduced innervation of itch-evoking nerve fibers, gelatinase activity and nerve growth factor (NGF) expression in the epidermis but upregulated semaphorin-3A (Sema3A) expression in the epidermis, along with reduced scratching behavior in TNCB-treated NC/Nga mice. All of these effects were completely reversed by co-treatment with the NK1R antagonist CP99994. In cultured human keratinocytes, SP treatment reduced expression of TGF-α, but upregulated TGF-β and Sema3A. Topically administered SP can restore normal skin barrier function, reduce epidermal infiltration

  2. Fiber

    Science.gov (United States)

    ... white toast. Lunch and Dinner: Make sandwiches with whole-grain breads (rye, oat, or wheat) instead of white. Make a fiber-rich sandwich with whole-grain bread, peanut butter, and bananas. Use whole-grain spaghetti ...

  3. Diffusion tensor imaging of the auditory nerve in patients with acquired single-sided deafness

    DEFF Research Database (Denmark)

    Vos, Sjoerd; Haakma, Wieke; Versnel, Huib

    2015-01-01

    following cochlear hair cell loss, and the amount of degeneration may considerably differ between the two ears, also in patients with bilateral deafness. A measure that reflects the nerve's condition would help to assess the best of both nerves and decide accordingly which ear should be implanted...... for optimal benefit from a CI. Diffusion tensor MRI (DTI) may provide such a measure, by allowing noninvasive investigations of the nerve's microstructure. In this pilot study, we show the first use of DTI to image the auditory nerve in five normal-hearing subjects and five patients with long-term profound...... single-sided sensorineural hearing loss. A specialized acquisition protocol was designed for a 3 T MRI scanner to image the small nerve bundle. The nerve was reconstructed using fiber tractography and DTI metrics - which reflect the nerve's microstructural properties - were computed per tract. Comparing...

  4. Persistent alterations in active and passive electrical membrane properties of regenerated nerve fibers of man and mice

    DEFF Research Database (Denmark)

    Moldovan, Mihai; Alvarez Herrero, Susana; Rosberg, Mette R.

    2016-01-01

    patients with surgically repaired complete injuries of peripheral nerves of the arm 22 months-26 years prior to investigation, deviation of excitability measures was explained by a hyperpolarizing shift in the resting membrane potential and an increase in the passive 'Barrett and Barrett' conductance (GBB...

  5. Clues from Crouzon: Insights into the potential role of growth factors in the pathogenesis of myelinated retinal nerve fibers

    Directory of Open Access Journals (Sweden)

    Giancarlo A. Garcia

    2016-12-01

    Conclusions: This association of Crouzon syndrome with bilateral peripapillary MRNF may lend insight into the developmental control of optic nerve myelination, the pathogenesis of MRNF, and the potential role of growth factors in these processes. Further, OCT angiography allowed for excellent blood vessel visualization in this case of MRNF.

  6. A mathematical model for describing the retinal nerve fiber bundle trajectories in the human eye : Average course, variability, and influence of refraction, optic disc size and optic disc position

    NARCIS (Netherlands)

    Jansonius, Nomdo M.; Schiefer, Julia; Nevalainen, Jukka; Paetzold, Jens; Schiefer, Ulrich

    2012-01-01

    Previously we developed a mathematical model for describing the retinal nerve fiber bundle trajectories in the superior-temporal and inferior-temporal regions of the human retina, based on traced trajectories extracted from fundus photographs. Aims of the current study were to (i) validate the

  7. Fracture resistance of fiber posts: combinations of several small posts vs. standardized single post.

    Science.gov (United States)

    Porciani, Pier F; Vano, Michele; Radovic, Ivana; Goracci, Cecilia; Grandini, Simone; García-Godoy, Franklin; Ferrari, Marco

    2008-12-01

    To determine the fracture resistance of different sizes of standardized single fiber posts and the combinations of multiple small experimental posts. Single posts in three different sizes (1, 2 and 3; DT Light Posts, RTD; DT), as control, and seven different combinations of experimental small posts (Abrasive Technology), reproducing the sizes of several endodontic files were cemented in endodontic resin blocks. The combinations of small posts were made combining 2-4 small posts so as to reach the sizes of standardized DT posts. The posts were loaded at an angle of 45 degrees to the long axis of the block using a crosshead speed of 1 mm/minute until specimen failure. Ten posts/combinations were tested. Statistical analysis was performed using one-way ANOVA followed by Tamhane test for the post hoc comparisons (P fracture resistance increased when increasing the diameter of the post. The use of multiple posts resulted in fracture resistances comparable to that of the single post for two of the three diameters studied (DT1 and DT2). For the largest diameter (DT3), the use of multiple posts resulted in lower fracture resistances than did the single post.

  8. Development and evaluation of elastomeric hollow fiber membranes as small diameter vascular graft substitutes

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Pagán, Ángel E.; Kang, Yunqing [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Findlay, Michael W. [Department of Plastic and Reconstructive Surgery, Stanford University, Stanford, CA (United States); University of Melbourne Department of Surgery, Royal Melbourne Hospital, Parkville, VIC (Australia); Yang, Yunzhi, E-mail: ypyang@stanford.edu [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA (United States)

    2015-04-01

    Engineering of small diameter (< 6 mm) vascular grafts (SDVGs) for clinical use remains a significant challenge. Here, elastomeric polyester urethane (PEU)-based hollow fiber membranes (HFMs) are presented as an SDVG candidate to target the limitations of current technologies and improve tissue engineering designs. HFMs are fabricated by a simple phase inversion method. HFM dimensions are tailored through adjustments to fabrication parameters. The walls of HFMs are highly porous. The HFMs are very elastic, with moduli ranging from 1–4 MPa, strengths from 1–5 MPa, and max strains from 300–500%. Permeability of the HFMs varies from 0.5–3.5 × 10{sup −6} cm/s, while burst pressure varies from 25 to 35 psi. The suture retention forces of HFMs are in the range of 0.8 to 1.2 N. These properties match those of blood vessels. A slow degradation profile is observed for all HFMs, with 71 to 78% of the original mass remaining after 8 weeks, providing a suitable profile for potential cellular incorporation and tissue replacement. Both human endothelial cells and human mesenchymal stem cells proliferate well in the presence of HFMs up to 7 days. These results demonstrate a promising customizable PEU HFMs for small diameter vascular repair and tissue engineering applications. - Highlights: • Hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties could be tailored through adjustments to fabrication parameters. • Properties could match or exceed those of blood vessels. • HFM showed excellent compatibility in vitro. • HFMs have the potential to be used for small diameter vascular grafts.

  9. Evaluation of retinal nerve fiber layer thickness measurements using optical coherence tomography in patients with tobacco-alcohol-induced toxic optic neuropathy

    Directory of Open Access Journals (Sweden)

    Moura Frederico

    2010-01-01

    Full Text Available Three patients with progressive visual loss, chronic alcoholism and tabagism were submitted to a complete neuro-ophthalmic examination and to retinal nerve fiber layer (RNFL measurements using optical coherence tomography (OCT scanning. Two patients showed marked RNFL loss in the temporal sector of the optic disc. However, a third patient presented RNFL measurements within or above normal limits, based on the Stratus-OCT normative database. Such findings may be due to possible RNFL edema similar to the one that may occur in the acute phase of toxic optic neuropathies. Stratus-OCT was able to detect RNFL loss in the papillomacular bundle of patients with tobacco-alcohol-induced toxic optic neuropathy. However, interpretation must be careful when OCT does not show abnormality in order to prevent diagnostic confusion, since overestimation of RNFL thickness measurements is possible in such cases.

  10. A small-scale test for fiber release from carbon composites. [pyrolysis and impact

    Science.gov (United States)

    Gilwee, W. J., Jr.; Fish, R. H.

    1980-01-01

    A test method was developed to determine relative fiber loss from pyrolyzed composites with different resins and fiber construction. Eleven composites consisting of woven and unwoven carbon fiber reinforcement and different resins were subjected to the burn and impact test device. The composites made with undirectional tape had higher fiber loss than those with woven fabric. Also, the fiber loss was inversely proportional to the char yield of the resin.

  11. Ultrasound study is useful to discriminate between axonotmesis and neurotmesis also in very small nerves: a case of sensory digital ulnar branch study.

    Science.gov (United States)

    Renna, Rosaria; Rosaria, Renna; Coraci, Daniele; Daniele, Coraci; De Franco, Paola; Erra, Carmen; Ceruso, Massimo; Padua, Luca

    2012-12-01

    Discrimination between axonotmesis and neurotmesis is crucial in traumatic nerve injury. We present the case of a 43-year-old woman which presented hypoesthesia in the fourth and fifth right fingers, started after surgery for Dupuytren syndrome. At ultrasound study, the ulnar digital sensory branch was identified. Before the division into the two terminal branches, a neuroma was observed, while neurotmesis was excluded. This case shows the utility of ultrasonography in peripheral nervous system examination and the possibility of visualization of very small nerves and their terminal branches.

  12. Comparison of the nerve fiber layer of type 2 diabetic patients without glaucoma with normal subjects of the same age and sex

    Directory of Open Access Journals (Sweden)

    Takis A

    2014-02-01

    Full Text Available Alexandros Takis,1 Dimitrios Alonistiotis,1 Dimitrios Panagiotidis,1 Nikolaos Ioannou,1 Dimitris Papaconstantinou,2 Panagiotis Theodossiadis1 1Ophthalmological University Clinic of Athens, Attikon Hospital, Athens, Greece; 2Ophthalmological University Clinic of Athens, Geniko Kratiko Hospital, Athens, Greece Background: The retinal nerve fiber layer (RNFL thickness in patients with diabetes mellitus type 2 was compared to normal subjects of similar age and sex, having first excluded any risk factors for glaucoma. The correlation between the RNFL thickness and the severity of diabetic retinopathy was investigated at its primary stages and with other ocular and diabetic parameters. Methods: A prospective, case series study was carried out. Twenty-seven diabetic patients without diabetic retinopathy, 24 diabetic patients with mild retinopathy, and 25 normal, age-matched subjects underwent a complete ophthalmological examination and imaging with scanning laser polarimetry for the evaluation of the RNFL. Multivariate analysis was applied in order to investigate the correlation between RNFL and diabetic parameters, such as age, duration of diabetes, insulin therapy, levels of glycosylated hemoglobin; and ocular parameters, such as cup to disc ratio, levels of normal intraocular pressure, and central corneal thickness. Results: The mean inferior average of RNFL and the temporal-superior-nasal-inferior-temporal standard deviation were statistically significantly lower in both diabetic groups, and the nerve fiber index was higher (P=0.04 compared to the normal group. There was no statistically significant difference between the diabetic groups. The factor analysis showed no significant correlation between the RNFL and the previously mentioned diabetic and ocular parameters. Conclusion: The existence of diabetes should be seriously considered in evaluating the results of scanning laser polarimetry. Multivariate analysis for RNFL was used for the first

  13. Autocrine fibronectin from differentiating mesenchymal stem cells induces the neurite elongation in vitro and promotes nerve fiber regeneration in transected spinal cord injury.

    Science.gov (United States)

    Zeng, Xiang; Ma, Yuan-Huan; Chen, Yuan-Feng; Qiu, Xue-Cheng; Wu, Jin-Lang; Ling, Eng-Ang; Zeng, Yuan-Shan

    2016-08-01

    Extracellular matrix (ECM) expression is temporally and spatially regulated during the development of stem cells. We reported previously that fibronectin (FN) secreted by bone marrow mesenchymal stem cells (MSCs) was deposited on the surface of gelatin sponge (GS) soon after culture. In this study, we aimed to assess the function of accumulated FN on neuronal differentiating MSCs as induced by Schwann cells (SCs) in three dimensional transwell co-culture system. The expression pattern and amount of FN of differentiating MSCs was examined by immunofluorescence, Western blot and immunoelectron microscopy. The results showed that FN accumulated inside GS scaffold, although its mRNA expression in MSCs was progressively decreased during neural induction. MSC-derived neuron-like cells showed spindle-shaped cell body and long extending processes on FN-decorated scaffold surface. However, after blocking of FN function by application of monoclonal antibodies, neuron-like cells showed flattened cell body with short and thick neurites, together with decreased expression of integrin β1. In vivo transplantation study revealed that autocrine FN significantly facilitated endogenous nerve fiber regeneration in spinal cord transection model. Taken together, the present results showed that FN secreted by MSCs in the early stage accumulated on the GS scaffold and promoted the neurite elongation of neuronal differentiating MSCs as well as nerve fiber regeneration after spinal cord injury. This suggests that autocrine FN has a dynamic influence on MSCs in a three dimensional culture system and its potential application for treatment of traumatic spinal cord injury. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1902-1911, 2016. © 2016 Wiley Periodicals, Inc.

  14. Clinical evaluation of retinal nerve fiber layer atrophy in glaucoma--correlation between visual field damage and the funduscopic NFA appearance.

    Science.gov (United States)

    Kanatani, I

    1989-02-01

    The purpose of this report is to clarify the clinical significance of nerve fiber layer atrophy (NFA) in the diagnosis of glaucoma. The assessment was made only in the arcuate area, named F1 and F2 sectors. First, 29 eyes with glaucoma were evaluated. Rim/disc ratios were calculated in each the F1 and F2 sectors. The sensitivity corresponding to the F1 and F2 sectors was determined by automatic perimeter (Octopus). Each sector was divided into three subsectors in relation to the distance from the disc margin. Retinal sensitivity in the proximal subsector was closely correlated with the rim/disc ratio in the corresponding sector and with the enlargement of glaucomatous cupping. NFA was expressed as a proximal, a distal or a total atrophy pattern. Proximal and distal visual field damage was prone to be associated with the proximal and distal NFA type respectively. Second, we examined photographs of 784 normal eyes and 50 glaucomatous eyes. The difference in the ratio of appearance of NFA was statistically significant between the 20-30s and 40-60s age groups, and between the C/D ratio less than 0.5 and C/D ratio greater than 0.5 groups. The appearance of the NFA was also classified into five patterns, according to the width. Almost all the NFAs in the normal eyes showed milder patterns, whereas almost all the NFAs in the glaucoma group showed stronger patterns. It was suggested that one of the mechanisms that causes NFA in glaucoma was a strong nerve fiber drop out that differed from aging such as local circulatory disturbance. The findings indicate that the visual field damage in glaucoma can be estimated from the funduscopic appearance of NFA.

  15. Analysis of macular and nerve fiber layer thickness in multiple sclerosis patients according to severity level and optic neuritis episodes.

    Science.gov (United States)

    Soler García, A; Padilla Parrado, F; Figueroa-Ortiz, L C; González Gómez, A; García-Ben, A; García-Ben, E; García-Campos, J M

    2016-01-01

    Quantitative assessment of macular and nerve fibre layer thickness in multiple sclerosis patients with regard to expanded disability status scale (EDSS) and presence or absence of previous optic neuritis episodes. We recruited 62 patients with multiple sclerosis (53 relapsing-remitting and 9 secondary progressive) and 12 disease-free controls. All patients underwent an ophthalmological examination, including quantitative analysis of the nerve fibre layer and macular thickness using optical coherence tomography. Patients were classified according to EDSS as A (lower than 1.5), B (between 1.5 and 3.5), and C (above 3.5). Mean nerve fibre layer thickness in control, A, B, and C groups was 103.35±12.62, 99.04±14.35, 93.59±15.41, and 87.36±18.75μm respectively, with statistically significant differences (P<.05). In patients with no history of optic neuritis, history of episodes in the last 3 to 6 months, or history longer than 6 months, mean nerve fibre layer thickness was 99.25±13.71, 93.92±13.30 and 80.07±15.91μm respectively; differences were significant (P<.05). Mean macular thickness in control, A, B, and C groups was 220.01±12.07, 217.78±20.02, 217.68±20.77, and 219.04±24.26μm respectively. Differences were not statistically significant. The mean retinal nerve fibre layer thickness in multiple sclerosis patients is related to the EDSS level. Patients with previous optic neuritis episodes have a thinner retinal nerve fibre layer than patients with no history of these episodes. Mean macular thickness is not correlated to EDSS level. Copyright © 2014 Sociedad Española de Neurología. Publicado por Elsevier España, S.L.U. All rights reserved.

  16. Ultrastructural organization of human corneal nerves.

    Science.gov (United States)

    Müller, L J; Pels, L; Vrensen, G F

    1996-03-01

    Although the human cornea is densely innervated, observations of the nerve fiber distribution and ultrastructure are scarce. This study aimed to provide a detailed electron microscopic analysis of nerve fibers in the central and peripheral human cornea. Samples from seven fresh corneas, obtained from the eyes of persons with melanoma, were processed for light and electron microscopic examinations. Both frontal and cross-sections were studied. Furthermore, serial ultrathin sections from the mid-epithelium to the anterior stroma were used. Unmyelinated nerve fiber bundles (as many as 30 nerve fibers and cross-section as large as 20 micrometers) run parallel to the stromal collagen fibers. Nerve fibers contain clear, dense cored and dense vesicles and are ensheathed by thin rims of Schwann cell protrusions and amorphic matrix. Some nerve fibers invaginate the cytoplasm of keratocytes. After passing through Bowman's membrane, bundles of straight fibers (cross-section 0.1 to 0.5 micrometers) and single-beaded nerve fibers, which both lack Schwann cell ensheathment, run parallel in an alternating manner. Beaded nerve fibers, containing many mitochondria and glycogen (cross-section as large as 2 micrometers), turn upward and invaginate both basal and wing cells. Except for the presence of myelinated nerve fibers in the peripheral stroma, no differences in the central cornea were observed. Nerve fibers invaginating epithelial cells and keratocytes suggest that both cell types are directly innervated. The presence of vesicles, mitochondria, and glycogen in stromal and epithelial nerve fibers suggest that classical and peptidergic transmitters, probably of sensory origin, innervate the human cornea. Peptidergic transmitters in nerve fibers may be involved in neuroimmunomodulation of the cornea.

  17. Optic disc and retinal nerve fiber layer parameters as indicators of neurodegenerative brain changes in patients with obstructive sleep apnea syndrome.

    Science.gov (United States)

    Huseyinoglu, Nergiz; Ekinci, Metin; Ozben, Serkan; Buyukuysal, Cagatay; Kale, Murat Yildirim; Sanivar, Hilal Safak

    2014-03-01

    Retina is a unique part of the central nervous system (CNS) for visualizing the processes of axonal and neuronal degeneration. Optical coherence tomography (OCT) allows direct visualization and measurement of retinal nerve fiber layer (RNFL) thickness, macular volume, and optic disc (OD) parameters. One of the disorders associated with atrophy in different brain regions is obstructive sleep apnea syndrome (OSAS). In the present study, we aimed to determine OD and RNFL changes measured by OCT for investigating the progress of neurodegeneration development in OSAS, excluding all the other conditions that can directly affect RNFL thickness and optic nerve parameters. Both eyes of 101 patients with OSAS and 20 controls were investigated by OCT. Full-night polysomnography (PSG) and ophthalmologic examination including automated visual field (VF) examination and OCT were performed in all of the patients. According to the OSAS grading, patients were grouped as mild (n=15), moderate (n=27), and severe (n=59). We found significant decrease in RNFL thickness only in the patients with severe OSAS compared with the other groups and decreased macular ganglion cell thickness in the severe OSAS group compared with the control group. VF parameters were significantly worsened in all the OSAS subgroups compared to the control group. We found different data such as normal or increased optic nerve parameters as result of subtle OD edema, which may mask possible peripapillar axonal loss. We think that evaluation of neurodegeneration in OSAS is not always possible by examining OD and RNFL because there are difficulties due to the confounding issues of cerebral atrophy and OD edema.

  18. Ganglion cell complex and retinal nerve fiber layer measured by fourier-domain optical coherence tomography for early detection of structural damage in patients with preperimetric glaucoma

    Directory of Open Access Journals (Sweden)

    Rolle T

    2011-07-01

    Full Text Available Teresa Rolle, Cristina Briamonte, Daniela Curto, Federico Maria GrignoloEye Clinic, Section of Ophthalmology, Department of Clinical Physiopathology, University of Torino, Torino, ItalyAims: To evaluate the capability of Fourier-domain optical coherence tomography (FD-OCT to detect structural damage in patients with preperimetric glaucoma.Methods: A total of 178 Caucasian subjects were enrolled in this cohort study: 116 preperimetric glaucoma patients and 52 healthy subjects. Using three-dimensional FD-OCT, the participants underwent imaging of the ganglion cell complex (GCC and the optic nerve head. Sensitivity, specificity, likelihood ratios, and predictive values were calculated for all parameters at the first and fifth percentiles. Areas under the curves (AUCs were generated for all parameters and were compared (Delong test. For both the GCC and the optic nerve head protocols, the OR logical disjunction (Boolean logic operator was calculated.Results: The AUCs didn’t significantly differ. Macular global loss volume had the largest AUC (0.81. Specificities were high at both the fifth and first percentiles (up to 97%, but sensitivities were low, especially at the first percentile (55%–27%.Conclusion: Macular and papillary diagnostic accuracies did not differ significantly based on the 95% confidence interval. The computation of the Boolean OR operator has been found to boost diagnostic accuracy. Using the software-provided classification, sensitivity and diagnostic accuracy were low for both the retinal nerve fiber layer and the GCC scans. FD-OCT does not seem to be decisive for early detection of structural damage in patients with no functional impairment. This suggests that there is a need for analysis software to be further refined to enhance glaucoma diagnostic capability.Keywords: OCT, RNFL, GCC, diagnostic accuracy 

  19. Repetitive nerve stimulation and single-fiber electromyography in the evaluation of patients with suspected myasthenia gravis or Lambert-Eaton myasthenic syndrome: Review of recent literature.

    Science.gov (United States)

    Chiou-Tan, Faye Y; Gilchrist, James M

    2015-09-01

    Our aim in this study was to provide an updated literature review of electrodiagnostic testing in myasthenia gravis and Lambert-Eaton myasthenic syndrome. A systematic review of the recent literature was performed using the following key words: myasthenia gravis (MG); Lambert-Eaton myasthenic syndrome (LEMS); electromyography (EMG); repetitive nerve stimulation (RNS); single-fiber electromyography (SFEMG); nerve conduction study; and normative values. Several articles supported testing of facial, bulbar, and respiratory muscles in the diagnosis of neuromuscular junction (NMJ) disorders, including muscle-specific kinase antibody (MuSK)-seropositive MG. Several articles supported use of concentric needle EMG as an alternative to SFEMG jitter in disorders of neuromuscular transmission. A limited number of articles addressed measurement of area (vs. amplitude) decrement in RNS and decreasing the threshold of post-exercise facilitation. Electrodiagnostic testing continues to be useful for diagnosis of MG and LEMS, although the quality of the evidence is not great. This literature review summarizes RNS and jitter measurement of facial and respiratory muscles and use of concentric needle EMG for SFEMG. © 2015 American Association of Neuromuscular and Electrodiagnostic Medicine.

  20. Effect of image registration on longitudinal analysis of retinal nerve fiber layer thickness of non-human primates using Optical Coherence Tomography (OCT).

    Science.gov (United States)

    Liu, Shuang; Datta, Anjali; Ho, Derek; Dwelle, Jordan; Wang, Daifeng; Milner, Thomas E; Rylander, Henry Grady; Markey, Mia K

    2015-01-01

    In this paper we determined the benefits of image registration on estimating longitudinal retinal nerve fiber layer thickness (RNFLT) changes. RNFLT maps around the optic nerve head (ONH) of healthy primate eyes were measured using Optical Coherence Tomography (OCT) weekly for 30 weeks. One automatic algorithm based on mutual information (MI) and the other semi-automatic algorithm based on log-polar transform cross-correlation using manually segmented blood vessels (LPCC_MSBV), were used to register retinal maps longitudinally. We compared the precision and recall between manually segmented image pairs for the two algorithms using a linear mixed effects model. We found that the precision calculated between manually segmented image pairs following registration by LPCC_MSBV algorithm is significantly better than the one following registration by MI algorithm (p registration. RNFLT of clock hours 1, 2, and 10 showed significant change over 30 weeks (p = 0.0058, 0.0054, and 0.0298 for clock hours 1, 2 and 10 respectively) without registration, but stayed constant over time with registration. The LPCC_MSBV provides better registration of RNFLT maps recorded on different dates than the automatic MI algorithm. Registration of RNFLT maps can improve clinical analysis of glaucoma progression.

  1. Characterization of small particles in liquid suspension by fiber-optofluidic platform

    Science.gov (United States)

    Djinovic, Zoran; Tomic, Milos; Stojkovic, Marijana; Milojkovic, Martin

    2015-06-01

    A method for characterization of small particles in downstream regime of water suspension is presented. Lowcoherence interferometric technique, based on fiber-optic Mach-Zehnder interferometer (MZI) integrated into the optofluidic platform, is applied for measuring refraction index and size, i.e. diameter of glass particles. Water suspension of glass balls and cylinders of different size (from 50-230μm in diameter) has been involved into the microchannels of the optofluidic platform under laminar flow. Two complementary algorithms have been applied for calculation of index of refraction and diameter of spherical glass parts out of raw interference signals. The accuracy of index of refraction measurement is about 1% that is predominantly determined by the accuracy of reading the position of mechanical scanner.

  2. Small-area fiber-coupled scintillation camera for imaging beta-ray distributions intraoperatively

    Science.gov (United States)

    MacDonald, L. R.; Tornai, Martin P.; Levin, C. S.; Park, J.; Atac, Muzaffer; Cline, David B.; Hoffman, Eric G.

    1995-09-01

    A small area, imaging, scintillation probe is being developed for locating small amounts of radio-labeled malignant tissue during surgery. Preliminary in brain surgery, avoiding the removal of excess tissue is a priority. It is possible to locate the main body of a brain tumor both before and during surgery, but once the bulk of the tumor is excised the identification of residual malignant tissue is difficult. A probe that covers an area of 1-2 cm(superscript 2) with an intrinsic resolution of 1-2 mm could locate small tumor masses that pose a threat of recurrence of the disease, and prevent removal of healthy tissue. A pre-operative injection of tumor seeking, beta emitting radiopharmaceutical (e.g. (superscript 18)fluorodeoxyuridine-FDUR-) will label the tumor. The limited range of beta-rays ensures proximity upon successful detection. Plastic scintillators are used for beta detection, and visible light photon counters (VLPCs) detect the scintillation light. For maneuverability in and around the surgical cavity, the scintillators are coupled to the VLPCs via 2 m of optical fiber. An imaging device can cover the tissue bed in a time compatible with surgery, as opposed to a single element detector on the order of 1-2 mm in size with comparable resolution. An imager also distinguishes high background rates (such as from annihilation gammas in FDUR) and concentrations of activity.

  3. Structure optimization of small-diameter polarization-maintaining photonic crystal fiber for mini coil of spaceborne miniature fiber-optic gyroscope.

    Science.gov (United States)

    Song, Ningfang; Cai, Wei; Song, Jingming; Jin, Jing; Wu, Chunxiao

    2015-11-20

    A small-diameter polarization-maintaining photonic crystal fiber (PM-PCF) for mini coils of spaceborne miniature fiber-optic gyroscopes is proposed in this paper. To ensure the strength of the small-diameter PM-PCF, a four-ring air holes structure is adopted. Using the full vector finite element method, dependence studies of modal field distribution, birefringence, and confinement loss on several key structure parameters are numerically investigated. The optimized parameter region is obtained. An optimized PM-PCF is fabricated, which can achieve similar to or even better optical properties than that of commercial PM-PCFs. The coating and cladding diameters of the optimized PM-PCF are 135 μm and 100 μm, respectively. Meanwhile, the optimized small-diameter PM-PCF shows a proof test level of 0.5%. The attenuation of the PM-PCF at 1550 nm is ∼2  dB/km. Typical volume of a mini coil wound with 300 m optimized PM-PCF is 5.9  cm3, which is decreased by ∼60% compared with a commercial PM-PCF coil of the same length. The bias stability of this coil is comparable with that of a conventional PMF coil of comparable length. Thus, the optimized small-diameter PM-PCF is suitable for mini coils of spaceborne miniature fiber-optic gyroscopes.

  4. Synthesis and characterization of polycaprolactone urethane hollow fiber membranes as small diameter vascular grafts

    Energy Technology Data Exchange (ETDEWEB)

    Mercado-Pagán, Ángel E. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Stahl, Alexander M. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Chemistry, Stanford University, Stanford, CA (United States); Ramseier, Michelle L. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Chemical Engineering, Stanford University, Stanford, CA (United States); Behn, Anthony W. [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Yang, Yunzhi, E-mail: ypyang@stanford.edu [Department of Orthopedic Surgery, Stanford University, Stanford, CA (United States); Department of Materials Science and Engineering, Stanford University, Stanford, CA (United States); Department of Bioengineering, Stanford University, Stanford, CA (United States)

    2016-07-01

    The design of bioresorbable synthetic small diameter (< 6 mm) vascular grafts (SDVGs) capable of sustaining long-term patency and endothelialization is a daunting challenge in vascular tissue engineering. Here, we synthesized a family of biocompatible and biodegradable polycaprolactone (PCL) urethane macromers to fabricate hollow fiber membranes (HFMs) as SDVG candidates, and characterized their mechanical properties, degradability, hemocompatibility, and endothelial development. The HFMs had smooth surfaces and porous internal structures. Their tensile stiffness ranged from 0.09 to 0.11 N/mm and their maximum tensile force from 0.86 to 1.03 N, with minimum failure strains of approximately 130%. Permeability varied from 1 to 14 × 10{sup −6} cm/s, burst pressures from 1158 to 1468 mm Hg, and compliance from 0.52 to 1.48%/100 mm Hg. The suture retention forces ranged from 0.55 to 0.81 N. HFMs had slow degradation profiles, with 15 to 30% degradation after 8 weeks. Human endothelial cells proliferated well on the HFMs, creating stable cell layer coverage. Hemocompatibility studies demonstrated low hemolysis (< 2%), platelet activation, and protein adsorption. There were no significant differences in the hemocompatibility of HFMs in the absence and presence of endothelial layers. These encouraging results suggest great promise of our newly developed materials and biodegradable elastomeric HFMs as SDVG candidates. - Highlights: • Polyester urethane hollow fiber membranes (HFMs) were fabricated and evaluated. • HFM properties varied according to composition. • HFM inner and outer surfaces were successfully seeded with cells. • HFMs showed excellent hemocompatibility in vitro. • HFM has the potential to be used for small diameter vascular grafts.

  5. [Early reactive changes of myelin sheath in the area of myelin sheath gaps (nodes of Ranvier) in nerve fibers (a supravital study)].

    Science.gov (United States)

    Sotnikov, O S; Kokurina, T N; Solov'eva, I A; Sergeeva, S S

    2011-01-01

    Using the inverted phase contrast microscope, the supravital study of structural dynamics of single myelin sheath gaps (nodes of Ranvier) of isolated frog myelin nerve fibers was performed after mechanical injury and in the medium with the decreased ion force under the conditions which induce, in electrophysiological experiments, the expression of the axolemmal K+-channels in the paranodal area. Videorecording has shown that within this area the myelin sheath stratification appeared that was associated with the swelling of Schwann cell cytoplasm enclosed in the terminal membranous loops of myelin. An increase of the degree of stratification of the lamellar myelin complexes make them invisible in the light microscope; therefore, it is not the translocation of the myelin sheath from the node cleft that is recorded, as many authors believed, but a shift of only the visible border of the compact, yet unstratified myelin sheath. Hence, the removal of myelin (demyelination) was absent, and the electrophysiological effect can be accounted for by a significant fall of electrical resistance in paranodal area as a result of swelling of terminal loops and stratification of the myelin sheath. Preparations examination also revealed a decrease of the axonal diameter in, which is proportional to swelling of the myelin sheath terminal parts. Since the outer fiber diameter did not change, it can be concluded that the process observed is the result of swelling of the Schwann cell cytoplasm due to the axoplasm water fraction which may be a peculiar process of axo-glial interactions.

  6. Compound action potential of sensory tail nerves in the rat.

    Science.gov (United States)

    Leandri, Massimo; Saturno, Moreno; Cilli, Michele; Bisaglia, Michela; Lunardi, Gianluigi

    2007-01-01

    Assessment of the conduction velocity of motor fibers of the rat tail nerves has been used by some authors in the past, but very little is known about the sensory fibers. In 10 adult rats, weighing between 320 and 380 g, responses from the nerves and muscles of the tail have been recorded after stimulation at its root and tip. It was found that stimulation of the tip involved mainly sensory fibers, of which two main groups could be identified. One faster group, conducting within the range of 38-27 m/s, and one slower group with range 14-7 m/s. The bipolar recording configuration was found to be optimal for sensory recording. Stimulation of the tail root evoked a motor response, which was preceded by a very small neurographic activity, due to the fastest sensory fibers conducting antidromically. The conduction velocity of motor fibers was calculated to be approximately 19 m/s. Distance traveled by the volley can be assessed with excellent precision on the tail nerves; hence the calculated conduction velocities are highly reliable and reproducible. We propose that the tail nerves may be a useful tool for evaluation of conduction velocity of Abeta and Adelta afferents. As the technique is just minimally invasive, the test can be repeated a number of times in animals under chronic experimental conditions.

  7. Comparison of the corneal biomechanical properties, optic nerve head topographic parameters, and retinal nerve fiber layer thickness measurements in diabetic and non-diabetic primary open-angle glaucoma.

    Science.gov (United States)

    Akkaya, Serkan; Can, Ertuğrul; Öztürk, Faruk

    2016-10-01

    The purpose of this study is to investigate the corneal biomechanical properties, optic nerve head (ONH) topographic parameters, and retinal nerve fiber layer (RNFL) thickness changes in primary open-angle glaucoma (POAG) patients with and without diabetes, as well as to evaluate the effect of the metabolic control of diabetes on corneal biomechanical properties, ONH topography, and RNFL thickness. A total of 101 eyes of 101 POAG patients (60 with diabetes and 41 without diabetes) were recruited in this prospective study. Corneal hysteresis and corneal resistance factor (CRF) were both measured using the ocular response analyzer. Optic disk parameters were evaluated using the Heidelberg Retina Tomograph-III. RNFL thickness was measured by using Spectralis HRA + OCT. CRF, mean rim area, and rim volume were found to be significantly higher in the diabetic group when compared with non-diabetic group (p = 0.01 for CRF, p = 0.04 for rim area and p = 0.02 for rim volume). ANCOVA analysis showed statistically insignificant effects of age, gender, MD, and PSD values over rim area and rim volume (p > 0.05). CRF was not significantly correlated with HbA1c levels (p > 0.05). Cup area (CA), cup volume (CV), and cup shape measure (CSM) were weakly correlated with HbA1c levels (r = 0.35 and p = 0.006 for CA; r = 0.32 and p = 0.01 for CV; r = 0.32 and p = 0.01 for CSM). The difference in mean RNFL thickness values between the groups was found to be insignificant (p > 0.05). The results of this study raise doubts whether or not diabetes does in fact shield POAG patients from glaucomatous optic nerve damage from various perspectives.

  8. Bilateral muscle fiber and nerve influences by TNF-alpha in response to unilateral muscle overuse - studies on TNF receptor expressions.

    Science.gov (United States)

    Renström, Lina; Stål, Per; Song, Yafeng; Forsgren, Sture

    2017-11-28

    TNF-alpha is suggested to be involved in muscle damage and muscle inflammation (myositis). In order to evaluate whether TNF-alpha is involved in the myositis that occurs in response to muscle overuse, the aim was to examine the expression patterns of TNF receptors in this condition. A rabbit muscle overuse model leading to myositis in the soleus muscle was used. The expression patterns of the two TNF receptors Tumor Necrosis Factor Receptor type 1 (TNFR1) and Tumor Necrosis Factor Receptor type 2 (TNFR2) were investigated. In situ hybridization and immunofluorescence were utilized. Immunostainings for desmin, NK-1R and CD31 were made in parallel. Immunoreactions (IR) for TNF receptors were clearly observed in white blood cells, fibroblasts and vessel walls, and most interestingly also in muscle fibers and nerve fascicles in the myositis muscles. There were very restricted reactions for these in the muscles of controls. The upregulation of TNF receptors was for all types of structures seen for both the experimental side and the contralateral nonexperimental side. TNF receptor expressing muscle fibers were present in myositis muscles. They can be related to attempts for reparation/regeneration, as evidenced from results of parallel stainings. Necrotic muscle fibers displayed TNFR1 mRNA and TNFR2 immunoreaction (IR) in the invading white blood cells. In myositis muscles, TNFR1 IR was observed in both axons and Schwann cells while TNFR2 IR was observed in Schwann cells. Such observations were very rarely made for control animals. The findings suggest that there is a pronounced involvement of TNF-alpha in the developing myositis process. Attempts for reparation of the muscle tissue seem to occur via both TNFR1 and TNFR2. As the myositis process also occurs in the nonexperimental side and as TNF receptors are confined to nerve fascicles bilaterally it can be asked whether TNF-alpha is involved in the spreading of the myositis process to the contralateral side via the

  9. The furcal nerve revisited

    Directory of Open Access Journals (Sweden)

    Nanjundappa S. Harshavardhana

    2014-10-01

    Full Text Available Atypical sciatica and discrepancy between clinical presentation and imaging findings is a dilemma for treating surgeon in management of lumbar disc herniation. It also constitutes ground for failed back surgery and potential litigations thereof. Furcal nerve (Furcal = forked is an independent nerve with its own ventral and dorsal branches (rootlets and forms a link nerve that connects lumbar and sacral plexus. Its fibers branch out to be part of femoral and obturator nerves in-addition to the lumbosacral trunk. It is most commonly found at L4 level and is the most common cause of atypical presentation of radiculopathy/sciatica. Very little is published about the furcal nerve and many are unaware of its existence. This article summarizes all the existing evidence about furcal nerve in English literature in an attempt to create awareness and offer insight about this unique entity to fellow colleagues/ professionals involved in spine care.

  10. Poly(ADP-ribosylation is present in murine sciatic nerve fibers and is altered in a Charcot-Marie-Tooth-1E neurodegenerative model

    Directory of Open Access Journals (Sweden)

    Laura I. Lafon Hughes

    2017-05-01

    regions. Is PAR stabilizing the AJ-actin complexes? This question has strong implications in structural cell biology and cell signaling networks. Moreover, if PAR played a stabilizing role, such stabilization could participate in the physiological control of axonal branching. PARP and PAR alterations exist in several neurodegenerative pathologies including Alzheimer’s, Parkinson’s and Hungtington’s diseases. Conversely, PARP inhibition decreases PAR and promotes neurite outgrowth in cortical neurons in vitro. Coherently, the PARP inhibitor XAV939 improves myelination in vitro, ex vivo and in vivo. Until now such results have been interpreted in terms of nuclear PARP activity. Our results indicate for the first time the presence of PARylation in peripheral nerve fibers, in a healthy environment. Besides, we have evidenced a PARylation increase in Tr-J, suggesting that the involvement of cytoplasmic PARPs and PARylation in normal and neurodegenerative conditions should be re-evaluated.

  11. A small-scale test for fiber release from carbon composites

    Science.gov (United States)

    Gilwee, W. J., Jr.; Fish, R. H.

    1979-01-01

    A burn/impact test apparatus is used to determine the amount of fiber release from carbon fiber composites after burn and impact. The calculation of the theoretical char binder content of the composite is made based on the temperature of the test specimen and the char yield of the resin as determined by thermogravimetric analysis. The test results indicate that carbon fiber release depends on the type of reinforcement used. There was more fiber release with the quasi-isotropic composite made with unidirectional tape than with the woven fabric reinforcement. The amount of fiber release in the impact chamber after burning is coincident with the calculated char binder.

  12. Rapid adhesion of nerve cells to muscle fibers from adult rats is mediated by a sialic acid-binding receptor

    OpenAIRE

    1986-01-01

    Single viable muscle fibers isolated from adult rats by collagenase digestion rapidly bind dissociated spinal neurons or PC-12 cells but not a variety of other cells tested. The adhesion process is calcium- independent, temperature-sensitive, and is not blocked by pretreating cells with inhibitors of energy metabolism or actin polymerization. Adhesion is mediated by a carbohydrate-binding protein and can be inhibited by N-acetylneuraminic acid or mucin, a glycoprotein with high sialic acids c...

  13. Design of a Phase /Doppler Light-Scattering System for Measurement of Small-Diameter Glass Fibers During Fiberglass Manufacturing

    Science.gov (United States)

    Schaub, Scott A.; Naqwi, Amir A.; Harding, Foster L.

    1998-01-01

    We present fundamental studies examining the design of a phase /Doppler laser light-scattering system applicable to on-line measurements of small-diameter ( fiberglass manufacturing. We first discuss off-line diameter measurement techniques currently used in the fiberglass industry and outline the limitations and problems associated with these methods. For the phase /Doppler design study we have developed a theoretical computer model for the response of the measurement system to cylindrical fibers, which is based on electromagnetic scattering theory. The model, valid for arbitrary fiber diameters and hardware configurations, generates simulated detector output as a function of time for a finite absorbing, cylindrical fiber oriented perpendicular to the two incident laser beams. Results of experimental measurements are presented, confirming predictions of the theoretical model. Parametric studies have also been conducted using the computer model to identify experimental arrangements that provide linear phase -diameter relationships for small-diameter fibers, within the measurement constraints imposed by the fiberglass production environment. The effect of variations in optical properties of the glass as well as fiber orientation effects are discussed. Through this research we have identified phase /Doppler arrangements that we expect to have future applications in the fiberglass industry for on-line diameter monitoring and process control.

  14. Endocrine cells and nerve ganglia of the small intestine of the Opossum Didelphis aurita Wied-Neuwied, 1826 (Mammalia: Didelphidae

    Directory of Open Access Journals (Sweden)

    Gláucia M. Freitas-Ribeiro

    2012-09-01

    Full Text Available The nervous and endocrine systems jointly control intestinal movements, secretions of their glands and also participate of the processes of nutrient digestion and absorption. Therefore, the central objective of this study was to verify the existence of a possible relationship between the number of nervous cells and ganglia of the submucosal and myenteric plexuses and the number of endocrine cells in the small intestine of adult D. aurita. The utilized staining techniques were Grimelius, modified Masson-Fontana, direct immunoperoxidase and H-E. Argyrophillic, argentaffin and insulin immunoreactive endocrine cells do not numerically vary between the initial, mid and final regions of the duodenum, jejunum and ileum (P>0.05, except for argyrophillic cells in the jejunum (P>0.05. No numerical relationship has yet been verified between the number of nerve ganglia and endocrine cells, and also between nervous and endocrine cells. We recommended the use of new immunohistochemical techniques to confirm the numerical correlation between the nervous and endocrine systems in the small intestine. The morphology and distribution of endocrine cells and the nerve ganglia studied were similar to those encountered in eutherian mammals.Os sistemas nervoso e endócrino controlam integra-damente os movimentos intestinais, a secreção de suas glândulas e também participam dos processos de digestão e absorção de nutrientes. Portanto, o objetivo central deste estudo foi verificar a existência de uma possível relação entre o número de células nervosas e gânglios dos plexos submucosos e mioentéricos e o número de células endócrinas no intestino delgado de adultos de D. aurita. As técnicas de coloração utilizadas foram Grimelius, Masson-Fontana modificada, imunoperoxidase direta e H-E. As células endócrinas argirófilas, argentafins e imunorreativas à insulina não variaram numericamente entre as regiões inicial, média e final do duodeno, jejuno e

  15. Role of small conductance calcium-activated potassium channels expressed in PVN in regulating sympathetic nerve activity and arterial blood pressure in rats

    OpenAIRE

    Gui, Le; LaGrange, Lila P.; Larson, Robert A.; Gu, Mingjun; Zhu, Jianhua; Chen, Qing-Hui

    2012-01-01

    Small conductance Ca2+-activated K+ (SK) channels regulate membrane properties of rostral ventrolateral medulla (RVLM) projecting hypothalamic paraventricular nucleus (PVN) neurons and inhibition of SK channels increases in vitro excitability. Here, we determined in vivo the role of PVN SK channels in regulating sympathetic nerve activity (SNA) and mean arterial pressure (MAP). In anesthetized rats, bilateral PVN microinjection of SK channel blocker with peptide apamin (0, 0.125, 1.25, 3.75, ...

  16. The Functional Anatomy of Nerves Innervating the Ventral Grooved Blubber of Fin Whales (Balaenoptera Physalus).

    Science.gov (United States)

    Vogl, Wayne; Petersen, Hannes; Adams, Arlo; Lillie, Margo A; Shadwick, Robert E

    2017-11-01

    Nerves that supply the floor of the oral cavity in rorqual whales are extensible to accommodate the dramatic changes in tissue dimensions that occur during "lunge feeding" in this group. We report here that the large nerves innervating the muscle component of the ventral grooved blubber (VGB) in fin whales are branches of cranial nerve VII (facial nerve). Therefore, the muscles of the VGB are homologous to second branchial arch derived muscles, which in humans include the muscles of "facial expression." We speculate, based on the presence of numerous foramina on the dorsolateral surface of the mandibular bones, that general sensation from the VGB likely is carried by branches of the mandibular division (V3) of cranial nerve V (trigeminal nerve), and that these small branches travel in the lipid-rich layer directly underlying the skin. We show that intercostal and phrenic nerves, which are not extensible, have a different wall and nerve core morphology than the large VGB nerves that are branches of VII. Although these VGB nerves are known to have two levels of waviness, the intercostal and phrenic nerves have only one in which the nerve fascicles in the nerve core are moderately wavy. In addition, the VGB nerves have inner and outer parts to their walls with numerous large elastin fibers in the outer part, whereas intercostal and phrenic nerves have single walls formed predominantly of collagen. Our results illustrate that overall nerve morphology depends greatly on location and the forces to which the structures are exposed. Anat Rec, 300:1963-1972, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  17. Evaluation of the effect of intravitreal ranibizumab injections in patients with neovascular age related macular degeneration on retinal nerve fiber layer thickness using optical coherence tomography.

    Science.gov (United States)

    El-Ashry, Mohamed F; Lascaratos, Gerassimos; Dhillon, Baljean

    2015-01-01

    To evaluate the effect of repeated intravitreal ranibizumab injections for neovascular age related macular degeneration (nAMD) on the retinal nerve fiber layer (RNFL) thickness using optical coherence tomography. A prospective observational cohort study of patients with nAMD. Thirty eyes of 30 patients with nAMD were selected. All patients received three ranibizumab injections and underwent scans using the fast RNFL thickness protocol (Stratus optical coherence tomography) before starting the first injection and 1 month after the third injection. The RNFL thickness measurements prior to the injections and after the third injection were used for the analysis. We also evaluated the effect of the lens status as well as the type of choroidal neovascular membrane on RNFL thickness measurements pre- and post-injection. Pre- and post-injection average and individual quadrant RNFL thickness were measured and statistically analyzed. The mean (± standard deviation) pre-injection RNFL thickness was 90.8±18. The mean (± standard deviation) post-injection RNFL thickness was 91.03±15. The pre- and post-injection values of the mean RNFL thickness were not statistically significant. Likewise, the pre- and post-injection values for RNFL thickness in the different quadrants were not statistically significant. There was no statistical significance for the lens status or the type of choroidal neovascular membrane on the RNFL thickness. Repeated ranibizumab injections in nAMD appear to have no harmful effect on the RNFL thickness in the short term, in spite of the proven neurotrophic effect of vascular endothelial growth factor. Nevertheless, the safety profile of ranibizumab injections in nAMD needs to be further evaluated in a large multicenter trial with special emphasis on the long-term effects on the retina and optic nerve.

  18. Bone marrow-derived mesenchymal stem cells versus adipose-derived mesenchymal stem cells for peripheral nerve regeneration

    Directory of Open Access Journals (Sweden)

    Marcela Fernandes

    2018-01-01

    Full Text Available Studies have confirmed that bone marrow-derived mesenchymal stem cells (MSCs can be used for treatment of several nervous system diseases. However, isolation of bone marrow-derived MSCs (BMSCs is an invasive and painful process and the yield is very low. Therefore, there is a need to search for other alterative stem cell sources. Adipose-derived MSCs (ADSCs have phenotypic and gene expression profiles similar to those of BMSCs. The production of ADSCs is greater than that of BMSCs, and ADSCs proliferate faster than BMSCs. To compare the effects of venous grafts containing BMSCs or ADSCs on sciatic nerve injury, in this study, rats were randomly divided into four groups: sham (only sciatic nerve exposed, Matrigel (MG; sciatic nerve injury + intravenous transplantation of MG vehicle, ADSCs (sciatic nerve injury + intravenous MG containing ADSCs, and BMSCs (sciatic nerve injury + intravenous MG containing BMSCs groups. Sciatic functional index was calculated to evaluate the function of injured sciatic nerve. Morphologic characteristics of nerves distal to the lesion were observed by toluidine blue staining. Spinal motor neurons labeled with Fluoro-Gold were quantitatively assessed. Compared with sham-operated rats, sciatic functional index was lower, the density of small-diameter fibers was significantly increased, and the number of motor neurons significantly decreased in rats with sciatic nerve injury. Neither ADSCs nor BMSCs significantly improved the sciatic nerve function of rats with sciatic nerve injury, increased fiber density, fiber diameters, axonal diameters, myelin sheath thickness, and G ratios (axonal diameter/fiber diameter ratios in the sciatic nerve distal to the lesion site. There was no significant difference in the number of spinal motor neurons among ADSCs, BMSCs and MG groups. These results suggest that neither BMSCs nor ADSCs provide satisfactory results for peripheral nerve repair when using MG as the conductor for

  19. Facial nerve: electrophysiological reactions during in-vitro treatment with the ER:YAG laser

    Science.gov (United States)

    Mack, K. F.; Hagner, D.; Leinung, M.; Heermann, R.

    2001-10-01

    Our studies on the facial nerve of the rabbit are concerned with the development of a laser system by means of which tissue can be removed in the immediate vicinity of nerves without causing functional damage to the nerves. The risk of mechanical damage to nerve tissue, which inevitably occurs through pulling and through pressure in conventional surgery, is minimized by touch-free use of the laser. The basic necessary examinations involved bathing the freshly removed facial nerve from rabbit specimens in a nutrient medium inside a specially developed 'organ chamber' which enabled the nerve to be kept alive for many hours. Using successive laser treatment with pulse intensities of up to 100 mJ the laser spot was gradually approached from a lateral angle or radially through a small agarose plate and the electrical activity registered at the respective pulse intensity. The nerve and the conducting electrode were located in the organ chamber on a carriage which could be perceptibly shifted. In this way it proved possible to accurately record the position of the laser treatment for the histological examination. Our studies showed that an individual pulse of only 15 mJ striking the peripheral area of the facial nerve was sufficient to generate a clearly perceptible total action potential. A necessary precondition is, however, that a conducting electrode is placed directly over the nerve fiber bundle which is being irradiated. During conduction of the total action potential there is no observable transfer to the neighboring fiber bundle.

  20. Follow-up of the retinal nerve fiber layer thickness of diabetic patients type 2, as a predisposing factor for glaucoma compared to normal subjects

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    Takis A

    2017-06-01

    Full Text Available Alexandros Takis,1 Dimitrios Alonistiotis,1 Nikolaos Ioannou,1 Evgenia Kontou,1 Maria Mitsopoulou,1 Dimitrios Papaconstantinou2 1Second Department of Ophthalmology, University of Athens, “Attikon” Hospital, Athens, 2First Department of Ophthalmology, University of Athens, General Hospital of Athens “G Genimatas”, Athens, Greece Purpose: To evaluate and follow-up the retinal nerve fiber layer (RNFL thickness in patients with diabetes mellitus type 2 compared to a group of healthy individuals with similar demographic characteristics.Patients and methods: This is a prospective, noninvasive, observational case series study. For the purposes of the study, 27 eyes of diabetic patients without diabetic retinopathy, 24 eyes of patients with mild retinopathy, and 25 normal age-matched subjects (control group [CG] were examined. All participants underwent complete ophthalmological examination and imaging with GDx variable corneal compensation scanning laser polarimetry. Follow-up was 2 years for all three groups.Results: The mean inferior average was statistically significantly lower in both diabetic groups compared to CG at baseline examination and during follow-up. The nerve fiber indicator (NFI was higher in both diabetic groups compared to CG, both at baseline examination and during follow-up. The NFI was 21.7±11.9 and 22.0±11.8 for the diabetic group without retinopathy, 20.8±9.6 and 21.9±9.8 for the group with mild retinopathy, and 15.3±5.4 and 15.9±5.5 for the normal subjects, at baseline and 24 months, respectively. There was no statistically significant reduction of the RNFL thickness in all three groups compared to baseline examination.Conclusion: This is the first long-term study documenting the RNFL thickness in diabetic patients in comparison with normal controls. Although the lower RNFL was found thinner in diabetics, the 2-year follow-up showed no significant reduction of RNFL thickness in all groups, indicating that RNFL

  1. Retinal nerve fiber layer in primary open-angle glaucoma with high myopia determined by optical coherence tomography and scanning laser polarimetry.

    Science.gov (United States)

    Wang, Xiao-en; Wang, Xiao-yu; Gu, Yang-shun; Huang, Zhu

    2013-01-01

    Fundus changes associated with high myopia (HM) may mask those associated with primary open-angle glaucoma (POAG). This study aim to determine the characteristics of RNFL thickness changes in patients with both POAG and HM and compare these to changes in patients with only HM. The diagnostic capabilities of both OCT and GDxVCC in this subset of patients are also evaluated. Twenty-two eyes with POAG and HM (spherical equivalent (SE) between -6.0 and -12.0 D) were evaluated, and 22 eyes with HM were used for comparison. Characteristic retinal nerve fiber layer (RNFL) thickness profiles in patients with POAG and HM were examined using optical coherence tomography (OCT) and scanning laser polarimetry with variable corneal compensation (GDxVCC), and the diagnostic capabilities of these imaging modalities were compared. RNFL parameters evaluated included superior average (Savg-GDx), inferior average (Iavg-GDx), temporal-superior-nasal- inferior-temporal (TSNIT) average, and nerve fiber indicator (NFI) on GDxVCC and superior average (Savg-OCT), inferior average (Iavg-OCT), nasal average (Navg-OCT), temporal average (Tavg-OCT), and average thickness (AvgThick-OCT) on OCT (fast RNFL scan). Visual field testing was performed and defects were evaluated using mean defect (MD) and pattern standard deviation (PSD). The RNFL parameters (P < 0.05) significantly different between groups included Savg-GDx, Iavg-GDx, TSNIT average, NFI, Savg-OCT, Iavg-OCT, Tavg-OCT, and AvgThick-OCT. Significant correlations existed between TSNIT average and AvgThick-OCT (r = 0.778), TSNIT average and MD (r = 0.749), AvgThick-OCT and MD (r = 0.647), TSNIT average and PSD (r = -0.756), and AvgThick-OCT and PSD (r = -0.784). The area under the receiver operating characteristic curve (AUROC) values of TSNIT average, Savg-GDx, Iavg-GDx, NFI, Savg-OCT, Iavg-OCT, Navg-OCT, Tavg-OCT, and AvgThick-OCT were 0.947, 0.962, 0.973, 0.994, 0.909, 0.917, 0.511, 0.906, and 0.913, respectively. The NFI AUROC was the

  2. The Effect of LASIK Procedure on Peripapillary Retinal Nerve Fiber Layer and Macular Ganglion Cell-Inner Plexiform Layer Thickness in Myopic Eyes

    Directory of Open Access Journals (Sweden)

    Maja Zivkovic

    2017-01-01

    Full Text Available Purpose. To evaluate the effect of applied suction during microkeratome-assisted laser in situ keratomileusis (LASIK procedure on peripapillary retinal nerve fiber layer (RNFL thickness as well as macular ganglion cell-inner plexiform layer (GC-IPL thickness. Methods. 89 patients (124 eyes with established myopia range from −3.0 to −8.0 diopters and no associated ocular diseases were included in this study. RNFL and GC-IPL thickness measurements were performed by spectral domain optical coherence tomography (SD OCT one day before LASIK and at 1 and 6 months postoperatively. Results. Mean RNFL thickness prior to LASIK was 93.86±12.17 μm while the first month and the sixth month postoperatively were 94.01±12.04 μm and 94.46±12.27 μm, respectively. Comparing results, there is no significant difference between baseline, one month, and six months postoperatively for mean RNFL (p>0.05. Mean GC-IPL thickness was 81.70±7.47 μm preoperatively with no significant difference during the follow-up period (82.03±7.69 μm versus 81.84±7.64 μm; p>0.05. Conclusion. RNFL and GC-IPL complex thickness remained unaffected following LASIK intervention.

  3. Retinal nerve fiber layer and macular thinning in systemic lupus erythematosus: an optical coherence tomography study comparing SLE and neuropsychiatric SLE.

    Science.gov (United States)

    Liu, G Y; Utset, T O; Bernard, J T

    2015-10-01

    Due to the lack of reliable biomarkers in diagnosing and monitoring neuropsychiatric systemic lupus erythematosus (NPSLE), the aim of this study was to examine the utility of measurements obtained through spectral domain optical coherence tomography (SD-OCT) as a biomarker for NP involvement in SLE. Retinal nerve fiber layer (RNFL) and macula scans were performed using SD-OCT on 15 NPSLE patients, 16 SLE patients without NP symptoms (non-NP SLE), and 16 healthy controls. Macular volume and thickness of the central macula and peripapillary RNFL were compared between the groups and to scores on two validated cognitive tests. NPSLE patients did not differ significantly from non-NP SLE patients in retinal thickness or macular volume. However, SLE patients as a whole showed significant RNFL and macular thinning compared to controls. Scores on the Trail Making Test B, a test of complex attention, showed significant correlation to temporal superior and temporal inferior RNFL thickness. Our results demonstrate RNFL thinning in SLE, and confirm the previous finding of high incidence of abnormal brain scans in SLE. These findings suggest that OCT measurements may be indicative of neurodegeneration in SLE and may be a useful biomarker for early cognitive impairment in SLE. © The Author(s) 2015 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  4. Retinal nerve fiber layer and ganglion cell complex thickness assessment in patients with Alzheimer disease and mild cognitive impairment. Preliminary results

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    A. S. Tiganov

    2014-07-01

    Full Text Available Purpose: to investigate the retinal nerve fiber layer (RNFL and the macular ganglion cell complex (GCC in patients with Alzheimer`s disease and mild cognitive impairment.Methods: this study included 10 patients (20 eyes with Alzheimer`s disease, 10 patients with mild cognitive impairment and 10 age- and sex-matched healthy controls that had no history of dementia. All the subjects underwent psychiatric examination, including the Mini-Mental State Examination (MMSE, and complete ophthalmological examination, comprising optical coherence tomography and scanning laser polarimetry.Results: there was a significant decrease in GCC thickness in patients with Alzheimer`s disease compared to the control group, global loss volume of ganglion cells was higher than in control group. there was no significant difference among the groups in terms of RNFL thickness. Weak positive correlation of GCC thickness and MMSE results was observed.Conclusion: Our data confirm the retinal involvement in Alzheimer`s disease, as reflected by loss of ganglion cells. Further studies will clear up the role and contribution of dementia in pathogenesis of optic neuropathy.

  5. Traveling waves on the organ of corti of the chinchilla cochlea: spatial trajectories of inner hair cell depolarization inferred from responses of auditory-nerve fibers.

    Science.gov (United States)

    Temchin, Andrei N; Recio-Spinoso, Alberto; Cai, Hongxue; Ruggero, Mario A

    2012-08-01

    Spatial magnitude and phase profiles for inner hair cell (IHC) depolarization throughout the chinchilla cochlea were inferred from responses of auditory-nerve fibers (ANFs) to threshold- and moderate-level tones and tone complexes. Firing-rate profiles for frequencies ≤2 kHz are bimodal, with the major peak at the characteristic place and a secondary peak at 3-5 mm from the extreme base. Response-phase trajectories are synchronous with peak outward stapes displacement at the extreme cochlear base and accumulate 1.5 period lags at the characteristic places. High-frequency phase trajectories are very similar to the trajectories of basilar-membrane peak velocity toward scala tympani. Low-frequency phase trajectories undergo a polarity flip in a region, 6.5-9 mm from the cochlear base, where traveling-wave phase velocity attains a local minimum and a local maximum and where the onset latencies of near-threshold impulse responses computed from responses to near-threshold white noise exhibit a local minimum. That region is the same where frequency-threshold tuning curves of ANFs undergo a shape transition. Since depolarization of IHCs presumably indicates the mechanical stimulus to their stereocilia, the present results suggest that distinct low-frequency forward waves of organ of Corti vibration are launched simultaneously at the extreme base of the cochlea and at the 6.5-9 mm transition region, from where antiphasic reflections arise.

  6. Surgically induced changes in retinal vessel diameter, retinal nerve fiber layer thickness, and the optic disc after 23-gauge vitreoretinal surgical procedures

    Directory of Open Access Journals (Sweden)

    Seung Uk Lee

    2016-05-01

    Full Text Available AIM:To investigate the retinal vascular caliber, retinal nerve fiber layer(RNFLthickness, and optic disc changes in patients after pars plana vitrectomy and adjunctive intraoperative procedures.METHODS:We examined 40 eyes in 40 patients who had undergone unilateral pars plana vitrectomy and adjunctive intraoperative procedure at three time points:prior to surgery, and at 3mo and 6mo after the operation. The diameters of central retinal arteries and veins were measured using retinal photographs. The central retinal arteriolar equivalent(CRAEand central retinal venular equivalent(CRVEwere calculated using the revised Parr-Hubbard formula. RNFL thickness was obtained using Stratus optical coherence tomography. The cup-to-disc vertical ratio of the optic disc was evaluated using stereo optic disc photography.RESULTS:There were no significant differences between the eyes of individual patients before the operation. Cup-to-disc vertical ratios of the optic disc were significantly increased 3mo and 6mo postoperatively(PPPPPPCONCLUSION:Whereas there were no changes in RNFL thickness, vitrectomy and adjunctive intraoperative procedures induced changes in the cup-to-disc vertical ratio of the optic disc and retinal vessel diameter for at least 6mo after surgery.

  7. Correct calculation circle location of optical coherence tomography in measuring retinal nerve fiber layer thickness in eyes with myopic tilted discs.

    Science.gov (United States)

    Chung, Jae Keun; Yoo, Young Cheol

    2011-10-07

    PURPOSE. Retinal nerve fiber layer (RNFL) thickness measured by optical coherence tomography (OCT) can be unreliable in the presence of a myopic tilted disc. The purpose of this study was to investigate the influence of the calculation circle location of spectral domain (SD)-OCT when measuring RNFL thickness in healthy subjects with myopic tilted disc. METHODS. Sixty-nine eyes with myopic tilted disc and no other ocular abnormalities were analyzed. In all eyes, RNFL thickness was measured twice: first, along a calculation circle determined by a built-in algorithm (referred to as circle 1) and then along a manually positioned calculation circle based on the contours of the neural canal opening (NCO) (referred to as circle 2). The mean number of clock hours below normal at the 5% level and the proportion of eyes with abnormally thin clock hours at the 5% level were compared between the two methods: RESULTS. The mean number of clock hours below normal at the 5% level was significantly lower in circle 2 (0.84 ± 1.31) than in circle 1 (1.42 ± 1.43; P circle 2 (42%) than in circle 1 (69.9%). CONCLUSIONS. In subjects with myopic tilted disc, RNFL thickness measurements along the calculation circle based on the contours of the NCO seem to be more comparable to the normative database of the SD-OCT than does the automatically determined scan position.

  8. Effects of vitamin D on retinal nerve fiber layer in vitamin D deficient patients with optic neuritis: Preliminary findings of a randomized, placebo-controlled trial

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    Mehri Salari

    2015-01-01

    Full Text Available Background: There is accumulating evidence for a possible protective role of vitamin D in the development and disease course of multiple sclerosis. Whether vitamin D is also effective in treating patients with optic neuritis (ON is not known. The aim of this study was to evaluate the effect of oral vitamin D on the thickness of retinal nerve fiber layer (RNFL in vitamin D deficient patients with ON by optical coherence tomography. Materials and Methods: A Phase II placebo-controlled randomized clinical trial conducted between July 2011 and November 2012 included 52 patients with confirmed unilateral ON aged 15-38 years and low serum 25-hydroxyvitamin D levels. The main outcome measures were changes in thickness of RNFL and macula 6 months after treatment. Patients were randomly allocated to receive 6 months of treatment with adding either 50,000 IU/week vitamin D or placebo. Results: In the 27 patients treated with vitamin D, the mean (standard deviation [SD] thickness of RNFL decreased from 111.3 (18.9 μm at baseline to 91.4 (13.3 at the end of study period (P 0.05. Average thickness of RNFL at the end of trial did not differ between groups. Conclusion: Adding vitamin D to routine disease therapy had no significant effect on the thickness of RNFL or macula in patients with ON. This trial is registered on www.clinicaltrials.gov (ID NCT01465893.

  9. Ganglion cell-inner plexiform layer and retinal nerve fiber layer thickness according to myopia and optic disc area: a quantitative and three-dimensional analysis.

    Science.gov (United States)

    Seo, Sam; Lee, Chong Eun; Jeong, Jae Hoon; Park, Ki Ho; Kim, Dong Myung; Jeoung, Jin Wook

    2017-03-11

    To determine the influences of myopia and optic disc size on ganglion cell-inner plexiform layer (GCIPL) and peripapillary retinal nerve fiber layer (RNFL) thickness profiles obtained by spectral domain optical coherence tomography (OCT). One hundred and sixty-eight eyes of 168 young myopic subjects were recruited and assigned to one of three groups according to their spherical equivalent (SE) values and optic disc area. All underwent Cirrus HD-OCT imaging. The influences of myopia and optic disc size on the GCIPL and RNFL thickness profiles were evaluated by multiple comparisons and linear regression analysis. Three-dimensional surface plots of GCIPL and RNFL thickness corresponding to different combinations of myopia and optic disc size were constructed. Each of the quadrant RNFL thicknesses and their overall average were significantly thinner in high myopia compared to low myopia, except for the temporal quadrant (all Ps ≤0.003). The average and all-sectors GCIPL were significantly thinner in high myopia than in moderate- and/or low-myopia (all Ps ≤0.002). The average OCT RNFL thickness was correlated significantly with SE (0.81 μm/diopter, P Myopia can significantly affect GCIPL and RNFL thickness profiles, and optic disc size has a significant influence on RNFL thickness. The current OCT maps employed in the evaluation of glaucoma should be analyzed in consideration of refractive status and optic disc size.

  10. Effect of suction on macular thickness and retinal nerve fiber layer thickness during LASIK used femtosecond laser and Moria M2 microkeratome.

    Science.gov (United States)

    Zhang, Jing; Zhou, Yue-Hua

    2015-01-01

    To compare the effect of suction on the macular thickness and retinal nerve fiber layer (RNFL) thickness during laser in situ keratomileusis (LASIK) used Ziemer FEMTO LDV femtosecond laser (Ziemer group) and Moria M2 automated microkeratome (Moria group) for flap creation. Fourier-domain optical coherence tomography (FD-OCT) was used to measure macular thickness, ganglion cell complex thickness and (RNFL) thickness of 204 eyes of 102 patients with the Ziemer femtosecond laser (102 eyes) and the Moria M2 microkeratome (102 eyes) before surgery and 30min; 1, 3d; 1wk; 1, 3mo; 1y after surgery. The average foveal thickness and parafoveal retinal thickness 30min after the surgery were statistically more than that before surgery (Ziemer Peffect was less in the Ziemer group than that in the Moria group (P allthickness was not significantly changed in both groups (P all>0.05). The RNFL thickness was statistically less 30min after surgery in both groups (P=0.014, Pthickness had recovered to the preoperative level only 1d after surgery. The suction of femtosecond laser and mechanical microkeratome led to the increase in macular central fovea thickness and the decrease in RNFL thickness values at the early stage after LASIK. The effect of suction on macular and the RNFL thicknesses in Ziemer group is smaller than that in Moria group.

  11. The Effect of LASIK Procedure on Peripapillary Retinal Nerve Fiber Layer and Macular Ganglion Cell-Inner Plexiform Layer Thickness in Myopic Eyes.

    Science.gov (United States)

    Zivkovic, Maja; Jaksic, Vesna; Giarmoukakis, Athanassios; Grentzelos, Michael; Zlatanovic, Marko; Zlatanovic, Gordana; Miljkovic, Aleksandra; Jovanovic, Svetlana; Stamenkovic, Miroslav; Kymionis, George

    2017-01-01

    To evaluate the effect of applied suction during microkeratome-assisted laser in situ keratomileusis (LASIK) procedure on peripapillary retinal nerve fiber layer (RNFL) thickness as well as macular ganglion cell-inner plexiform layer (GC-IPL) thickness. 89 patients (124 eyes) with established myopia range from -3.0 to -8.0 diopters and no associated ocular diseases were included in this study. RNFL and GC-IPL thickness measurements were performed by spectral domain optical coherence tomography (SD OCT) one day before LASIK and at 1 and 6 months postoperatively. Mean RNFL thickness prior to LASIK was 93.86 ± 12.17 μm while the first month and the sixth month postoperatively were 94.01 ± 12.04 μm and 94.46 ± 12.27 μm, respectively. Comparing results, there is no significant difference between baseline, one month, and six months postoperatively for mean RNFL (p > 0.05). Mean GC-IPL thickness was 81.70 ± 7.47 μm preoperatively with no significant difference during the follow-up period (82.03 ± 7.69 μm versus 81.84 ± 7.64 μm; p > 0.05). RNFL and GC-IPL complex thickness remained unaffected following LASIK intervention.

  12. A Small U-Shaped Bending-Induced Interference Optical Fiber Sensor for the Measurement of Glucose Solutions

    Directory of Open Access Journals (Sweden)

    Yu-Lin Fang

    2016-09-01

    Full Text Available The study proposes a small U-shaped bending-induced interference optical fiber sensor; this novel sensor is a probe-type sensor manufactured using a mechanical device, a heat source, optical fiber and a packaging module. This probe-type sensor overcomes the shortcomings of conventional optical fibers, including being difficult to repair and a tendency to be influenced by external forces. We manufactured three types of sensors with different curvature radiuses. Specifically, sensors with three radiuses (1.5 mm, 2.0 mm, and 3.0 mm were used to measure common water and glucose solutions with concentrations of between 6% and 30% (the interval between concentrations was 4%. The results show that the maximal sensitivity was 0.85 dB/% and that the linearly-dependent coefficient was 0.925. The results further show that not only can the small U-shaped bending-induced interference optical fiber sensor achieve high sensitivity in the measurement of glucose solutions, but that it can also achieve great stability and repeatability.

  13. Flow injection small-volume fiber-optic pH sensor based on evanescent wave excitation and fluorescence determination.

    Science.gov (United States)

    Xiong, Yan; Huang, Ying; Ye, Zhongbin; Guan, Yafeng

    2011-05-01

    A small-volume fiber-optic pH sensor (FOEWS) based on evanescent wave excitation is developed and evaluated. The sensor is simply fabricated by inserting a decladded optical fiber into a transparent capillary tube. A microchannel between the optical fiber and the capillary inner wall was formed and acted as flow cell for solution flowing through. The pH-sensitive fluorophore of fluorescein can be excited by the evanescent wave field produced on the fiber core surface to produce emission fluorescence. pH value was then sensed by its enhancing effect on the emission fluorescence intensity. The response range of the sensor is from pH 2.09 to pH 8.85 and the linear range is from pH 3.25 to 8.85. The proposed sensor has a small detection volume of 2.5 μL and a short response time of 8 s. It has been applied to measure pH values of real water samples and was in good agreement with the results obtained by commercial pH meter. © Springer Science+Business Media, LLC 2010

  14. Gain and noise properties of small-signal erbium-doped fiber amplifiers pumped in the 980-nm band

    DEFF Research Database (Denmark)

    Pedersen, B.; Chirravuri, J.; Miniscalco, W. J.

    1992-01-01

    The authors have experimentally and theoretically investigated the effects of detuning the pump wavelength on the gain and noise properties of small-signal, erbium-doped fiber amplifiers codirectionally pumped in the 980-nm band. While the pump wavelength can be varied over a wide range with litt...... impact on the gain, a noise penalty is incurred. For amplifiers saturated by amplified spontaneous emission, it is possible to increase the gain by detuning the pump wavelength......The authors have experimentally and theoretically investigated the effects of detuning the pump wavelength on the gain and noise properties of small-signal, erbium-doped fiber amplifiers codirectionally pumped in the 980-nm band. While the pump wavelength can be varied over a wide range with little...

  15. Fiber-optic ultrasonic hydrophone using short Fabry-Perot cavity with multilayer reflectors deposited on small stub.

    Science.gov (United States)

    Kim, Kyung-Su; Mizuno, Yosuke; Nakamura, Kentaro

    2014-04-01

    A fiber-optic probe with dielectric multilayer films deposited on a small stub is studied for mega-hertz ultrasonic-wave detection in water. The small stub with a short Fabry-Perot cavity and distributed reflectors is attached on the fiber end. The structure is mechanically strong and withstands intense ultrasonic pressure. Ultrasonic waves at 1.56MHz are successfully detected in water with a good signal-to-noise ratio. The working principle and the characteristics are studied by comparing the ultrasonic sensitivity with that of a conventional piezoelectric hydrophone. The distance response and directional response are also investigated. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Heterogeneous pattern of retinal nerve fiber layer in multiple sclerosis. High resolution optical coherence tomography: potential and limitations.

    Science.gov (United States)

    Serbecic, Nermin; Aboul-Enein, Fahmy; Beutelspacher, Sven C; Graf, Martin; Kircher, Karl; Geitzenauer, Wolfgang; Brannath, Werner; Lang, Priska; Kristoferitsch, Wolfgang; Lassmann, Hans; Reitner, Andreas; Schmidt-Erfurth, Ursula

    2010-11-08

    Recently the reduction of the retinal nerve fibre layer (RNFL) was suggested to be associated with diffuse axonal damage in the whole CNS of multiple sclerosis (MS) patients. However, several points are still under discussion. (1) Is high resolution optical coherence tomography (OCT) required to detect the partly very subtle RNFL changes seen in MS patients? (2) Can a reduction of RNFL be detected in all MS patients, even in early disease courses and in all MS subtypes? (3) Does an optic neuritis (ON) or focal lesions along the visual pathways, which are both very common in MS, limit the predication of diffuse axonal degeneration in the whole CNS? The purpose of our study was to determine the baseline characteristics of clinical definite relapsing-remitting (RRMS) and secondary progressive (SPMS) MS patients with high resolution OCT technique. Forty-two RRMS and 17 SPMS patients with and without history of uni- or bilateral ON, and 59 age- and sex-matched healthy controls were analysed prospectively with the high resolution spectral-domain OCT device (SD-OCT) using the Spectralis 3.5mm circle scan protocol with locked reference images and eye tracking mode. Furthermore we performed tests for visual and contrast acuity and sensitivity (ETDRS, Sloan and Pelli-Robson-charts), for color vision (Lanthony D-15), the Humphrey visual field and visual evoked potential testing (VEP). All 4 groups (RRMS and SPMS with or without ON) showed significantly reduced RNFL globally, or at least in one of the peripapillary sectors compared to age-/sex-matched healthy controls. In patients with previous ON additional RNFL reduction was found. However, in many RRMS patients the RNFL was found within normal range. We found no correlation between RNFL reduction and disease duration (range 9-540 months). RNFL baseline characteristics of RRMS and SPMS are heterogeneous (range from normal to markedly reduced levels).

  17. Heterogeneous pattern of retinal nerve fiber layer in multiple sclerosis. High resolution optical coherence tomography: potential and limitations.

    Directory of Open Access Journals (Sweden)

    Nermin Serbecic

    Full Text Available BACKGROUND: Recently the reduction of the retinal nerve fibre layer (RNFL was suggested to be associated with diffuse axonal damage in the whole CNS of multiple sclerosis (MS patients. However, several points are still under discussion. (1 Is high resolution optical coherence tomography (OCT required to detect the partly very subtle RNFL changes seen in MS patients? (2 Can a reduction of RNFL be detected in all MS patients, even in early disease courses and in all MS subtypes? (3 Does an optic neuritis (ON or focal lesions along the visual pathways, which are both very common in MS, limit the predication of diffuse axonal degeneration in the whole CNS? The purpose of our study was to determine the baseline characteristics of clinical definite relapsing-remitting (RRMS and secondary progressive (SPMS MS patients with high resolution OCT technique. METHODOLOGY: Forty-two RRMS and 17 SPMS patients with and without history of uni- or bilateral ON, and 59 age- and sex-matched healthy controls were analysed prospectively with the high resolution spectral-domain OCT device (SD-OCT using the Spectralis 3.5mm circle scan protocol with locked reference images and eye tracking mode. Furthermore we performed tests for visual and contrast acuity and sensitivity (ETDRS, Sloan and Pelli-Robson-charts, for color vision (Lanthony D-15, the Humphrey visual field and visual evoked potential testing (VEP. PRINCIPAL FINDINGS: All 4 groups (RRMS and SPMS with or without ON showed significantly reduced RNFL globally, or at least in one of the peripapillary sectors compared to age-/sex-matched healthy controls. In patients with previous ON additional RNFL reduction was found. However, in many RRMS patients the RNFL was found within normal range. We found no correlation between RNFL reduction and disease duration (range 9-540 months. CONCLUSIONS: RNFL baseline characteristics of RRMS and SPMS are heterogeneous (range from normal to markedly reduced levels.

  18. Vasoactive intestinal polypeptidergic nerves and Brunner's gland secretion in the rat

    DEFF Research Database (Denmark)

    Poulsen, Steen Seier

    1981-01-01

    Vasoactive intestinal polypeptide is known to have powerful effect on the secretions from endocrine and exocrine glands. By immunohistochemical studies on the rat, both a dense network of vasoactive intestinal polypeptide-immunoreactive nerve fibers around the acini of Brunner's glands, and small...

  19. A Unique Case for Spinal Cord Stimulation: Successful Treatment of Small Fiber Neuropathy Pain Using Multiple Spinal Cord Stimulators

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    Maxim Eckmann

    2017-01-01

    Full Text Available Spinal cord stimulators have commonly been used to treat multiple pain conditions. This case report represents a unique case of using multiple spinal cord stimulators for widespread small fiber neuropathy pain. This case report concerns patient JJ who first presented with generalized neuropathic pain. His pain was an intermittent burning, stinging quality that originally focused in both of his feet and progressed to include his legs and arms and eventually involved his entire body. The pain would last moments to hours at least daily. He reported a poor quality of life. He was diagnosed with small fiber neuropathy with anhydrosis, suggestive of idiopathic erythromelalgia. He had a spinal cord stimulator trial involving both cervical and lower thoracic percutaneous leads. After two spinal cord stimulators were implanted, the patient began to report an improvement in pain. The patient continues to report excellent pain relief. The patient uses the stimulator intermittently as needed, in an abortive fashion for pain flares. The patient is very pleased and has increased his activity. He now attends graduate school full time. This case report hopes to illustrate a unique use of multiple spinal cord stimulators in treating widespread neuropathic pain caused by small fiber neuropathy.

  20. Nerve biopsy

    Science.gov (United States)

    Biopsy - nerve ... A nerve biopsy is most often done on a nerve in the ankle, forearm, or along a rib. The health care ... feel a prick and a mild sting. The biopsy site may be sore for a few days ...

  1. Expression of 5-HT3 receptors and TTX resistant sodium channels (NaV1.8) on muscle nerve fibers in pain-free humans and patients with chronic myofascial temporomandibular disorders

    Science.gov (United States)

    2014-01-01

    Background Previous studies have shown that 5-HT3-antagonists reduce muscle pain, but there are no studies that have investigated the expression of 5-HT3-receptors in human muscles. Also, tetrodotoxin resistant voltage gated sodium-channels (NaV) are involved in peripheral sensitization and found in trigeminal ganglion neurons innervating the rat masseter muscle. This study aimed to investigate the frequency of nerve fibers that express 5-HT3A-receptors alone and in combination with NaV1.8 sodium-channels in human muscles and to compare it between healthy pain-free men and women, the pain-free masseter and tibialis anterior muscles, and patients with myofascial temporomandibular disorders (TMD) and pain-free controls. Methods Three microbiopsies were obtained from the most bulky part of the tibialis and masseter muscles of seven and six healthy men and seven and six age-matched healthy women, respectively, while traditional open biopsies were obtained from the most painful spot of the masseter of five female patients and from a similar region of the masseter muscle of five healthy, age-matched women. The biopsies were processed by routine immunohistochemical methods. The biopsy sections were incubated with monoclonal antibodies against the specific axonal marker PGP 9.5, and polyclonal antibodies against the 5-HT3A-receptors and NaV1.8 sodium-channels. Results A similar percentage of nerve fibers in the healthy masseter (85.2%) and tibialis (88.7%) muscles expressed 5-HT3A-receptors. The expression of NaV1.8 by 5-HT3A positive nerve fibers associated with connective tissue was significantly higher than nerve fibers associated with myocytes (P < .001). In the patients, significantly more fibers per section were found with an average of 3.8 ± 3 fibers per section in the masseter muscle compared to 2.7 ± 0.2 in the healthy controls (P = .024). Further, the frequency of nerve fibers that co-expressed NaV1.8 and 5-HT3A receptors was significantly

  2. Expression of 5-HT3 receptors and TTX resistant sodium channels (Na(V)1.8) on muscle nerve fibers in pain-free humans and patients with chronic myofascial temporomandibular disorders.

    Science.gov (United States)

    Christidis, Nikolaos; Kang, Isabell; Cairns, Brian E; Kumar, Ujendra; Dong, Xudong; Rosén, Annika; Kopp, Sigvard; Ernberg, Malin

    2014-09-26

    Previous studies have shown that 5-HT3-antagonists reduce muscle pain, but there are no studies that have investigated the expression of 5-HT3-receptors in human muscles. Also, tetrodotoxin resistant voltage gated sodium-channels (NaV) are involved in peripheral sensitization and found in trigeminal ganglion neurons innervating the rat masseter muscle. This study aimed to investigate the frequency of nerve fibers that express 5-HT3A-receptors alone and in combination with NaV1.8 sodium-channels in human muscles and to compare it between healthy pain-free men and women, the pain-free masseter and tibialis anterior muscles, and patients with myofascial temporomandibular disorders (TMD) and pain-free controls. Three microbiopsies were obtained from the most bulky part of the tibialis and masseter muscles of seven and six healthy men and seven and six age-matched healthy women, respectively, while traditional open biopsies were obtained from the most painful spot of the masseter of five female patients and from a similar region of the masseter muscle of five healthy, age-matched women. The biopsies were processed by routine immunohistochemical methods. The biopsy sections were incubated with monoclonal antibodies against the specific axonal marker PGP 9.5, and polyclonal antibodies against the 5-HT3A-receptors and NaV1.8 sodium-channels. A similar percentage of nerve fibers in the healthy masseter (85.2%) and tibialis (88.7%) muscles expressed 5-HT3A-receptors. The expression of NaV1.8 by 5-HT3A positive nerve fibers associated with connective tissue was significantly higher than nerve fibers associated with myocytes (P < .001). In the patients, significantly more fibers per section were found with an average of 3.8 ± 3 fibers per section in the masseter muscle compared to 2.7 ± 0.2 in the healthy controls (P = .024). Further, the frequency of nerve fibers that co-expressed NaV1.8 and 5-HT3A receptors was significantly higher in patients (42

  3. Retinal nerve fiber layer thickness measured by optical coherence tomography in Chinese teenagers aged from 13 years old to 18 years old

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    Yu-Ming Zhang

    2014-04-01

    Full Text Available AIM: To establish a reference range of retinal nerve fiber layer(RNFLthickness by optical coherence tomography(OCTin Chinese teenagers aged from 13 to 18 years old, and investigate its relationship with age, eye side, gender, and ethnic group.METHODS: A total of 402 eyes from 201 normal Chinese aged from 13 to 18 years old were recruited for this study. Optic disk with 3.4mm diameter circle in different global average, quadrant and part-time bit retinal nerve fiber layer thickness(RNFLTwas measured by RNFL thickness average analysis program. Their RNFLT at different part-time bit, quadrant and global average RNFLT around the disc were measured by OCT with 3.4mm diameter circle, using the RNFL thickness average analysis program. The data was analyzed with SPSS statistical 19.0. The influences of several factors(such as age, eye side, gender, and ethnic groupon RNFLT were also analyzed.RESULTS: The global average RNFLT at 13, 14, 15, 16, 17, 18 years old was 108.32±9.42μm, 109.23±9.67μm, 110.36±11.14μm, 111.27±10.21μm, 109.23±9.67μm, 112.11±8.83μm respectively. RNFLT of right eyes was 109.82±8.93μm and of left eyes was 110.33±9.89μm. All of the male's average RNFLT was 110.14±10.02μm, and all of the female's average RNFLT was 109.96±11.22μm. The average RNFLT of Han nationality was 110.22±9.31μm and of non-Han nationality was 109.87±8.65μm. The average RNFLT of all was 110.02±9.87μm, the RNFLT at the superior, nasal, inferior and temporal quadrant was 146.56 ±18.88μm, 76.49±13.28μm, 136.64±16.29μm, 82.01±12.55μm respectively. There was no significant difference in gender, eye side, and ethnic group(all PCONCLUSION: This study has established a normal standard reference of RNFLT and its related indexes by OCT in Chinese teenagers aged 13-18 years old. Gender, age, eye side, and ethnic group have no effect on their RNFLT, which has significant difference with adult's data. And for the diagnosis and follow-up of

  4. The impact of motor and sensory nerve architecture on nerve regeneration.

    Science.gov (United States)

    Moradzadeh, Arash; Borschel, Gregory H; Luciano, Janina P; Whitlock, Elizabeth L; Hayashi, Ayato; Hunter, Daniel A; Mackinnon, Susan E

    2008-08-01

    Sensory nerve autografting is the standard of care for injuries resulting in a nerve gap. Recent work demonstrates superior regeneration with motor nerve grafts. Improved regeneration with motor grafting may be a result of the nerve's Schwann cell basal lamina tube size. Motor nerves have larger SC basal lamina tubes, which may allow more nerve fibers to cross a nerve graft repair. Architecture may partially explain the suboptimal clinical results seen with sensory nerve grafting techniques. To define the role of nerve architecture, we evaluated regeneration through acellular motor and sensory nerve grafts. Thirty-six Lewis rats underwent tibial nerve repairs with 5 mm double-cable motor or triple-cable sensory nerve isografts. Grafts were harvested and acellularized in University of Wisconsin solution. Control animals received fresh motor or sensory cable isografts. Nerves were harvested after 4 weeks and histomorphometry was performed. In 6 animals per group from the fresh motor and sensory cable graft groups, weekly walking tracks and wet muscle mass ratios were performed at 7 weeks. Histomorphometry revealed more robust nerve regeneration in both acellular and cellular motor grafts. Sensory groups showed poor regeneration with significantly decreased percent nerve, fiber count, and density (parchitecture (size of SC basal lamina tubes) plays an important role in nerve regeneration in a mixed nerve gap model.

  5. Measurement of peripapillary retinal nerve fiber layer thickness and macular thickness in anisometropia using spectral domain optical coherence tomography: a prospective study.

    Science.gov (United States)

    Singh, Neha; Rohatgi, Jolly; Gupta, Ved Prakash; Kumar, Vinod

    2017-01-01

    To study whether there is a difference in central macular thickness (CMT) and peripapillary retinal nerve fiber layer (RNFL) thickness between the two eyes of individuals having anisometropia >1 diopter (D) using spectral domain optical coherence tomography (OCT). One hundred and one subjects, 31 with myopic anisometropia, 28 with astigmatic anisometropia, and 42 with hypermetropic anisometropia, were enrolled in the study. After informed consent, detailed ophthalmological examination was performed for every patient including cycloplegic refraction, best corrected visual acuity, slit lamp, and fundus examination. After routine ophthalmic examination peripapillary RNFL and CMT were measured using spectral domain OCT and the values of the two eyes were compared in the three types of anisometropia. Axial length was measured using an A Scan ultrasound biometer (Appa Scan-2000). The average age of subjects was 21.7±9.3 years. The mean anisometropia was 3.11±1.7 D in myopia; 2±0.99 D in astigmatism; and 3.68±1.85 D in hypermetropia. There was a statistically significant difference in axial length of the worse and better eye in both myopic and hypermetropic anisometropia (P=0.00). There was no significant difference between CMT of better and worse eyes in anisomyopia (P=0.79), anisohypermetropia (P=0.09), or anisoastigmatism (P=0.16). In anisohypermetropia only inferior quadrant RNFL was found to be significantly thicker (P=0.011) in eyes with greater refractive error. There does not appear to be a significant difference in CMT and peripapillary RNFL thickness in anisomyopia and anisoastigmatism. However, in anisohypermetropia inferior quadrant RNFL was found to be significantly thicker.

  6. Measurement of retinal nerve fiber layer thickness in eyes with optic disc swelling by using scanning laser polarimetry and optical coherence tomography.

    Science.gov (United States)

    Hata, Masayuki; Miyamoto, Kazuaki; Oishi, Akio; Kimura, Yugo; Nakagawa, Satoko; Horii, Takahiro; Yoshimura, Nagahisa

    2014-01-01

    The retinal nerve fiber layer thickness (RNFLT) in patients with optic disc swelling of different etiologies was compared using scanning laser polarimetry (SLP) and spectral-domain optical coherence tomography (OCT). Forty-seven patients with optic disc swelling participated in the cross-sectional study. Both GDx SLP (enhanced corneal compensation) and Spectralis spectral-domain OCT measurements of RNFLT were made in 19 eyes with papilledema (PE), ten eyes with optic neuritis (ON), and 18 eyes with nonarteritic anterior ischemic optic neuropathy (NAION) at the neuro-ophthalmology clinic at Kyoto University Hospital. Differences in SLP (SLP-RNFLT) and OCT (OCT-RNFLT) measurements among different etiologies were investigated. No statistical differences in average OCT-RNFLT among PE, ON, and NAION patients were noted. Average SLP-RNFLT in NAION patients was smaller than in PE (P<0.01) or ON (P=0.02) patients. When RNFLT in each retinal quadrant was compared, no difference among etiologies was noted on OCT, but on SLP, the superior quadrant was thinner in NAION than in PE (P<0.001) or ON (P=0.001) patients. Compared with age-adjusted normative data of SLP-RNFLT, average SLP-RNFLT in PE (P<0.01) and ON (P<0.01) patients was greater. Superior SLP-RNFLT in NAION patients was smaller (P=0.026). The ratio of average SLP-RNFLT to average OCT-RNFLT was smaller in NAION than in PE (P=0.001) patients. In the setting of RNFL thickening, despite increased light retardance in PE and ON eyes, SLP revealed that NAION eyes have less retardance, possibly associated with ischemic axonal loss.

  7. Thickness of the Macula, Retinal Nerve Fiber Layer, and Ganglion Cell Layer in the Epiretinal Membrane: The Repeatability Study of Optical Coherence Tomography.

    Science.gov (United States)

    Lee, Haeng-Jin; Kim, Min-Su; Jo, Young-Joon; Kim, Jung-Yeul

    2015-07-01

    To analyze the repeatability of measurements of the thicknesses of the macula, retinal nerve fiber layer (RNFL), and ganglion cell inner plexiform layer (GCIPL) using spectral-domain optical coherence tomography (SD-OCT) in the epiretinal membrane (ERM). The prospective study analyzed patients who visited our retinal clinic from June 2013 to January 2014. An experienced examiner measured the thicknesses twice using macular cube 512 × 128 and optic disc cube 200 × 200 scans. The repeatability of the thicknesses of the macula, RNFL, and GCIPL were compared using the intraclass correlation coefficient (ICC) of two groups based on the central macular thickness (group A, ≤ 450 μm; group B, > 450 μm). A total of 88 patients were analyzed. The average thicknesses of the central macula, RNFL, and GCIPL were 256.5, 96.6, and 84.4 μm, respectively, in the normal fellow eye and 412.3, 94.6, and 56.7 μm in the affected eye. The ICCs of the central macula, RNFL, and GCIPL were 0.995, 0.994, and 0.996, respectively, for the normal fellow eye and 0.991, 0.973, and 0.881 for the affected eye. The average thicknesses of the central macula, RNFL, and GCIPL in group A were 360.9, 93.5, and 63.4 μm, respectively, and the ICCs were 0.997, 0.987, and 0.995. The thicknesses in group B were 489.5, 96.2, and 46.6 μm, respectively, and the ICCs were 0.910, 0.942, and 0.603, significantly lower repeatability compared with group A (P macula.

  8. Toxic Effects of Chronic Mercury Exposure on the Retinal Nerve Fiber Layer and Macular and Choroidal Thickness in Industrial Mercury Battery Workers

    Science.gov (United States)

    Ekinci, Metin; Ceylan, Erdinç; Keleş, Sadullah; Çağatay, Halil Hüseyin; Apil, Aytekin; Tanyıldız, Burak; Uludag, Gunay

    2014-01-01

    Background The aim of this study was to evaluate the toxic effects of mercury on retinal nerve fiber layer thickness (RNFLT), macular thickness (MT), and choroidal thickness (CT) by using spectral-domain optical coherence tomography (SD-OCT) in battery industry workers who had been chronically exposed to mercury. Material/Methods Battery factory workers (n=31) and healthy non-factory employee controls (n=15) participated in the study. Participants were divided into 3 groups: Group 1 (n=15) was factory workers who had worked for more than 5 years in a mercury battery factory; Group 2 (n=16) was factory worker who had worked for less than 5 years in a mercury battery factory; and Group 3 (n=15) was healthy non-employees. Systemic symptoms were recorded. Ophthalmic examination included best-corrected visual acuity test, color vision test, full ophthalmologic examination, and SD-OCT of the RNLF, macula, and choroid. To determine mercury exposure, venous blood samples were collected and mercury levels were assessed. Results In our study group the most common systemic symptoms were insomnia (67.7%) and fatigue (67.7%). There were no significant differences between Group 1 and Group 2, but there were significant differences between Group 3 and both Group 1 and Group 2 in best-corrected visual acuity values (1=2mercury levels, and duration (mean ±SD, range) of mercury exposure(1>2>3). OCT values of RNFLTs, MTs, and CTs of all 3 groups were statistically different from each another (1mercury. PMID:25056093

  9. Toxic effects of chronic mercury exposure on the retinal nerve fiber layer and macular and choroidal thickness in industrial mercury battery workers.

    Science.gov (United States)

    Ekinci, Metin; Ceylan, Erdinç; Keleş, Sadullah; Cağatay, Halil Hüseyin; Apil, Aytekin; Tanyıldız, Burak; Uludag, Gunay

    2014-07-24

    The aim of this study was to evaluate the toxic effects of mercury on retinal nerve fiber layer thickness (RNFLT), macular thickness (MT), and choroidal thickness (CT) by using spectral-domain optical coherence tomography (SD-OCT) in battery industry workers who had been chronically exposed to mercury. Battery factory workers (n=31) and healthy non-factory employee controls (n=15) participated in the study. Participants were divided into 3 groups: Group 1 (n=15) was factory workers who had worked for more than 5 years in a mercury battery factory; Group 2 (n=16) was factory worker who had worked for less than 5 years in a mercury battery factory; and Group 3 (n=15) was healthy non-employees. Systemic symptoms were recorded. Ophthalmic examination included best-corrected visual acuity test, color vision test, full ophthalmologic examination, and SD-OCT of the RNLF, macula, and choroid. To determine mercury exposure, venous blood samples were collected and mercury levels were assessed. In our study group the most common systemic symptoms were insomnia (67.7%) and fatigue (67.7%). There were no significant differences between Group 1 and Group 2, but there were significant differences between Group 3 and both Group 1 and Group 2 in best-corrected visual acuity values (1=2mercury levels, and duration (mean ±SD, range) of mercury exposure(1>2>3). OCT values of RNFLTs, MTs, and CTs of all 3 groups were statistically different from each another (1exposure to mercury.

  10. Diagnostic capability of peripapillary retinal nerve fiber layer parameters in time-domain versus spectral-domain optical coherence tomography for assessing glaucoma in high myopia

    Directory of Open Access Journals (Sweden)

    Mei-Ching Teng

    2017-07-01

    Full Text Available AIM: To evaluate and compare the diagnostic capabilities of peripapillary retinal nerve fiber layer (p-RNFL parameters of Spectralis optical coherence tomography (OCT versus Stratus OCT to detect glaucoma in patients with high myopia. METHODS: This is a retrospective, cross-sectional study. Sixty highly myopic eyes of 60 patients were enrolled, with 30 eyes in the glaucoma group and 30 eyes in the control group. All eyes received peripapillary imaging of the optic disc using Stratus and Spectralis OCT. Areas under the receiver operating characteristic curve (AUROC and the sensitivity at specificity of >80% and >95% for p-RNFL parameters obtained using the two devices to diagnose glaucoma were analysed and compared. RESULTS: In Spectralis OCT, p-RNFL thickness parameters with the largest AUROC were the temporal-inferior sector (0.974 and the inferior quadrant (0.951, whereas in Stratus OCT, the best parameters were the 7-o’clock sector (0.918 and the inferior quadrant (0.918. Compared to the Stratus OCT parameters, the Spectralis OCT parameters demonstrated generally higher AUROC; however, the difference was not statistically significant. CONCLUSION: The best p-RNFL parameters for diagnosing glaucoma in patients with high myopia were the temporal-inferior sector on Spectralis OCT and the 7-o’clock sector on Stratus OCT. There were no significant differences between the AUROCs for Spectralis OCT and Stratus OCT, which suggest that the glaucoma diagnostic capabilities of these two devices in patients with high myopia are similar.

  11. Prevention of Paclitaxel-induced allodynia by Minocycline: Effect on loss of peripheral nerve fibers and infiltration of macrophages in rats

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    Xin Wen-Jun

    2010-11-01

    Full Text Available Abstract Background Although paclitaxel is a frontline antineoplastic agent for treatment of solid tumors, the paclitaxel-evoked pain syndrome is a serious problem for patients. There is currently no valid drug to prevent or treat the paclitaxel-induced allodynia, partly due to lack of understanding regarding the cellular mechanism. Studies have shown that minocycline, an inhibitor of microglia/macrophage, prevented neuropathic pain and promoted neuronal survival in animal models of neurodegenerative disease. Recently, Cata et al also reported that minocycline inhibited allodynia induced by low-dose paclitaxel (2 mg/kg in rats, but the mechanism is still unclear. Results Here, we investigate by immunohistochemistry the change of intraepidermal nerve fiber (IENF in the hind paw glabrous skin, expression of macrophage and activating transcription factor 3 (ATF3 in DRG at different time points after moderate-dose paclitaxel treatment (cumulative dose 24 mg/kg; 3 × 8 mg/kg in rats. Moreover, we observe the effect of minocycline on the IENF, macrophages and ATF3. The results showed that moderate-dose paclitaxel induced a persisted, gradual mechanical allodynia, which was accompanied by the loss of IENF in the hind paw glabrous skin and up-regulation of macrophages and ATF3 in DRG in rats. The expressions of ATF3 mainly focus on the NF200-positive cells. More importantly, we observed that pretreatment of minocycline at dose of 30 mg/kg or 50 mg/kg, but not 5 mg/kg, prevented paclitaxel-evoked allodynia. The evidence from immunohistochemistry showed that 30 mg/kg minocycline rescued the degeneration of IENF, attenuated infiltration of macrophages and up-regulation of ATF3 induced by paclitaxel treatment in rats. Conclusions Minocycline prevents paclitaxel-evoked allodynia, likely due to its inhibition on loss of IENF, infiltration of macrophages and up-regulation of ATF3 in rats. The finding might provide potential target for preventing paclitaxel

  12. Evaluation of retinal nerve fiber layer and ganglion cell layer thickness in Alzheimer's disease using spectral-domain optical coherence tomography.

    Science.gov (United States)

    Marziani, Ermengarda; Pomati, Simone; Ramolfo, Paola; Cigada, Mario; Giani, Andrea; Mariani, Claudio; Staurenghi, Giovanni

    2013-09-05

    To evaluate differences between the retinal nerve fiber layer (RNFL) thickness and RNFL + ganglion cell layer (GCL) thickness in patients affected by Alzheimer's disease (AD) and healthy patients using spectral-domain optical coherence tomography (SD-OCT). This was a case-control prospective study. Twenty-one AD patients and 21 healthy subjects underwent neurological examination, clock-drawing test (CDT), Mini Mental State Examination (MMSE), and comprehensive ophthalmic evaluation with visual acuity. SD-OCT examination was performed using Spectralis and RTVue-100. An RNFL thickness map was obtained using the Spectralis volume protocol with 19 lines on the 30° field centered on the macula. On each B-scan, the outer RNFL limit was manually set. Statistical analysis was performed to assess interoperator RNFL evaluation thickness. An RNFL+GCL thickness map was obtained using the RTVue-100 MM6 protocol. Maps were divided into the nine ETDRS subfields and each map value in every area was evaluated. A single eye from each patient was randomly chosen to perform the analysis. Differences between AD and healthy subjects were assessed. The two study groups were age and sex matched. MMSE results were 19.9 ± 3.1 and 27.9 ± 1.3, respectively (P < 0.001). There was good agreement in the manual delimitation of the RNFL layer. There was a significant difference in the thickness of both the RNFL and the RNFL+GCL in all examined fields. For example, in the inferior internal subfield, the RNFL thickness was 28.1 ± 3.1 μm for AD patients and 32.6 ± 3.8 μm for healthy subjects (P < 0.001). These results indicate that RNFL and RNFL+GCL thickness measurements are reduced in AD patients compared with healthy subjects. This finding may represent a useful element for the diagnosis and follow-up of this pathology.

  13. Comparing the Rates of Retinal Nerve Fiber Layer and Ganglion Cell-Inner Plexiform Layer Loss in Healthy Eyes and in Glaucoma Eyes.

    Science.gov (United States)

    Hammel, Naama; Belghith, Akram; Weinreb, Robert N; Medeiros, Felipe A; Mendoza, Nadia; Zangwill, Linda M

    2017-06-01

    To compare the rates of circumpapillary retinal nerve fiber layer (RNFL) and macular retinal ganglion cell-inner plexiform layer (GCIPL) change over time in healthy and glaucoma eyes. Cohort study. The rates of circumpapillary RNFL and macular GCIPL loss in 28 healthy subjects and 97 glaucoma subjects from the Diagnostic Innovations in Glaucoma Study (DIGS) were compared using mixed-effects models. The median follow-up time and number of visits were 1.7 years and 6 visits and 3.2 years and 7 visits for healthy and glaucoma eyes, respectively. Significant rates of loss of both global circumpapillary RNFL and average macular GCIPL thickness were detectable in early and moderate glaucoma eyes; in severe glaucoma eyes, rates of average macular GCIPL loss were significant, but rates of global circumpapillary RNFL loss were not. In glaucoma eyes, mean rates of global circumpapillary RNFL thickness change (-0.98 μm/year [95% confidence interval (CI), -1.20 to -0.76]) and normalized global circumpapillary RNFL change (-1.7%/year [95% CI, -2.1 to -1.3]) were significantly faster than average macular GCIPL change (-0.57 μm/year [(95% CI, -0.73 to -0.41]) and normalized macular GCIPL change (-1.3%/year [95% CI, -1.7 to -0.9]). The rates of global and inferior RNFL change were weakly correlated with global and inferior macular GCIPL change (r ranges from 0.16 to 0.23, all P glaucoma eyes. Global circumpapillary RNFL thickness loss was detectable in early and moderate glaucoma, and average macular GCIPL thickness loss was detectable in early, moderate, and severe glaucoma, suggesting that structural changes can be detected in severe glaucoma. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. High glucose up-regulates Semaphorin 3A expression via the mTOR signaling pathway in keratinocytes: A potential mechanism and therapeutic target for diabetic small fiber neuropathy.

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    Wu, Liang-Yan; Li, Mei; Qu, Min-Li; Li, Xin; Pi, Lin-Hua; Chen, Zi; Zhou, Shan-Lei; Yi, Xiao-Qing; Shi, Xia-Jie; Wu, Jing; Wang, Shan

    2017-12-05

    Small fiber neuropathy (SFN) is a common complication in diabetes, and is characterized by decreased intraepidermal nerve fiber density (IENFD). Semaphorin 3A (Sema3A), which is produced by keratinocytes, has a chemorepulsive effect on intraepidermal nerve fibers. mTOR signaling can mediate local protein synthesis that is critical for growth of axons and dendrites. Therefore, this study aimed to investigate whether Sema3A is up-regulated in diabetic keratinocytes via the mTOR-mediated p70 S6K and 4E-BP1 signaling pathways, and furthermore whether it is involved in the pathogenesis of diabetic SFN. IENFD, expression of Sema3A, and mTOR signaling, were evaluated in the skin of diabetic patients with SFN as well as control subjects. Sema3A and mTOR signaling were also assessed in HaCaT cells which had been treated with high glucose (HG) or recombinant Sema3A (rSema3A) in the presence or absence of rapamycin. Small fiber dysfunction was evaluated by examining IENFD and using behavioral tests in control and streptozotocin-induced diabetic rats treated with or without rapamycin. We found that higher Sema3A expression and over-activation of mTOR signaling, was accompanied by reduced IENFD in the skin of diabetic patients compared with control subjects. The expression of Sema3A, and mTOR signaling were up-regulated in HaCaT cells incubated with HG or rSema3A, and this could be attenuated by rapamycin. Hyperalgesia, reduced IENFD, and up-regulated Sema3A and mTOR signaling were also detected in diabetic rats. These effects were ameliorated by rapamycin treatment. Our data indicate that HG up-regulates Sema3A expression by activating mTOR signaling in diabetic keratinocytes. This pathway may therefore play a critical role in diabetic SFN. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Macroscopic in vivo imaging of facial nerve regeneration in Thy1-GFP rats.

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    Placheta, Eva; Wood, Matthew D; Lafontaine, Christine; Frey, Manfred; Gordon, Tessa; Borschel, Gregory H

    2015-01-01

    Facial nerve injury leads to severe functional and aesthetic deficits. The transgenic Thy1-GFP rat is a new model for facial nerve injury and reconstruction research that will help improve clinical outcomes through translational facial nerve injury research. To determine whether serial in vivo imaging of nerve regeneration in the transgenic rat model is possible, facial nerve regeneration was imaged under the main paradigms of facial nerve injury and reconstruction. Fifteen male Thy1-GFP rats, which express green fluorescent protein (GFP) in their neural structures, were divided into 3 groups in the laboratory: crush-injury, direct repair, and cross-face nerve grafting (30-mm graft length). The distal nerve stump or nerve graft was predegenerated for 2 weeks. The facial nerve of the transgenic rats was serially imaged at the time of operation and after 2, 4, and 8 weeks of regeneration. The imaging was performed under a GFP-MDS-96/BN excitation stand (BLS Ltd). Facial nerve injury. Optical fluorescence of regenerating facial nerve axons. Serial in vivo imaging of the regeneration of GFP-positive axons in the Thy1-GFP rat model is possible. All animals survived the short imaging procedures well, and nerve regeneration was followed over clinically relevant distances. The predegeneration of the distal nerve stump or the cross-face nerve graft was, however, necessary to image the regeneration front at early time points. Crush injury was not suitable to sufficiently predegenerate the nerve (and to allow for degradation of the GFP through Wallerian degeneration). After direct repair, axons regenerated over the coaptation site in between 2 and 4 weeks. The GFP-positive nerve fibers reached the distal end of the 30-mm-long cross-face nervegrafts after 4 to 8 weeks of regeneration. The time course of facial nerve regeneration was studied by serial in vivo imaging in the transgenic rat model. Nerve regeneration was followed over clinically relevant distances in a small

  16. Small intestine development of laying hens fed different fiber sources diets and crude protein levels

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    MFFM Praes

    2011-09-01

    Full Text Available The objective of the presente study was to evaluate the effects on different dietary fiber sources and crude protein levels on the intestinal morphometry of commercial layers. Isa Brown® layers with 48 weeks of age were distributed in a completely randomized experimental design with a 3 x 2 + 1 factorial arrangement, resulting in seven treatments with seven replicates of eight birds each. At the end of the fourth experimental period (28 days each, birds were 64 weeks of age and were randomly chosen (two birds per replicate, totaling 14 birds per treatment, weighed and sacrificed by neck dislocation. Their intestine was dissected and the duodenum, jejunum and ileum were collected for subsequent analysis of intestinal morphometry. Treatments consisted of diets containing three different fiber sources (cottonseed hulls, soybean hulls or rice husks and two crude protein levels (12% or 16%. Soybean hulls and 16% crude protein level promoted, in general, an increase in villus height and crypt depth in the three intestinal segments. In the duodenum, the control diet resulted in higher villus height and crypt depth relative to the diets containing fiber. In the jejunum, higher crypt depth values. In the ileum, dietary fiber increased villus height as compared to the control diet.

  17. THICKNESS OF THE MACULA, RETINAL NERVE FIBER LAYER, AND GANGLION CELL-INNER PLEXIFORM LAYER IN THE AGE-RELATED MACULAR DEGENERATION: The Repeatability Study of Spectral Domain Optical Coherence Tomography.

    Science.gov (United States)

    Shin, Il-Hwan; Lee, Woo-Hyuk; Lee, Jong-Joo; Jo, Young-Joon; Kim, Jung-Yeul

    2018-02-01

    To determine the repeatability of measuring the thickness of the central macula, retinal nerve fiber layer, and ganglion cell-inner plexiform layer (GC-IPL) using spectral domain optical coherence tomography (Cirrus HD-OCT) in eyes with age-related macular degeneration. One hundred and thirty-four eyes were included. The measurement repeatability was assessed by an experienced examiner who performed two consecutive measurements using a 512 × 128 macular cube scan and a 200 × 200 optic disk cube scan. To assess changes in macular morphology in patients with age-related macular degeneration, the patients were divided into the following three groups according to the central macular thickness (CMT): A group, CMT 300 μm. Measurement repeatability was assessed using test-retest variability, a coefficient of variation, and an intraclass correlation coefficient. The mean measurement repeatability for the central macular, retinal nerve fiber layer, and GC-IPL thickness was high in the B group. The mean measurement repeatability for both the central macula and retinal nerve fiber layer thickness was high in the A and C groups, but was lower for the GC-IPL thickness. The measurement repeatability for GC-IPL thickness was high in the B group, but low in the A group and in the C group. The automated measurement repeatability for GC-IPL thickness was significantly lower in patients with age-related macular degeneration with out of normal CMT range. The effect of changes in macular morphology should be considered when analyzing GC-IPL thicknesses in a variety of ocular diseases.

  18. Characterizing Treatable Causes of Small Fiber Polyneuropathy in Gulf War Veterans

    Science.gov (United States)

    2016-10-01

    complaints [1, 2]. Neurological examination can be unrevealing in SFPN sincemuscle bulk, strength, tendon reflexes, and sensations of touch, position...the National Health and Nutrition Examination Survey (NHANES) or the Women’s Health Study (WHS). If US population data were not available, prevalences...hepatitis. Regarding nutritional contributors, folate deficiency usually produces large-fiber-predominant non-demyelinat- ing sensory axonopathy [27

  19. Correlation between the peripapillary retinal nerve fiber layer thickness,structure changes in non-proliferative diabetic retinopathy and the changes of visual function

    Directory of Open Access Journals (Sweden)

    Dong-Hua Tian

    2014-07-01

    Full Text Available AIM:To study the correlation between and the peripapillary retinal nerve fiber layer(RNFLthickness,structure changes in non-proliferative diabetic retinopathy(NPDRand the the changes of visual function METHODS:Eighty cases(80 eyesof patients with NPDR who were in our hospital from January 2011 to December 2013 as group NPDR, 60 cases of patients(60 eyeswithout retinopathy who were in the hospital were selected as non-diabetic retinopathy group(NRDgroup, meanwhile, 50 healthy people who had health examination in our hospital as control group. The RNFL thickness and visual electrophysiological testing were performed on the study objects in the three groups, and the results were compared among groups.RESULTS: Group NPDR's above, below, nasal, temporal and average RNFL thickness were 91.52±18.52, 88.63±21.65, 63.62±11.72, 60.42±9.13, 69.36±12.52μm,those of group NPDR were 111.32±21.90, 113.57±22.67, 74.31±11.74, 67.64±12.34, and 97.31±11.43μm,those of group control were 121.65±21.42, 129.32±23.31, 82.42±9.28, 80.32±8.51, 102.54±21.82μm. To compare of average thickness of RNFL of three groups, groups NPDR and NPD were thinner than that of control group; To compare each quadrant phase, above, below, nasal, the RNFL thickness among three groups had statistical significance(PP>0.05; At the same time, 60'P100 latency(MS, 60'P100 amplitude(V, 15'P100 latency(MSand 15'P100 amplitude(Vof three groups had statistical significance(PCONCLUSION: The changes of RNFL thickness have occurred in the early time of NPDR, and mainly the above, below and temporal, and it has a significant relevance with the changes of visual function.

  20. Short-term observations of the regenerative potential of injured proximal sensory nerves crossed with distal motor nerves

    Directory of Open Access Journals (Sweden)

    Xiu-xiu Zhang

    2017-01-01

    Full Text Available Motor nerves and sensory nerves conduct signals in different directions and function in different ways. In the surgical treatment of peripheral nerve injuries, the best prognosis is obtained by keeping the motor and sensory nerves separated and repairing the nerves using the suture method. However, the clinical consequences of connections between sensory and motor nerves currently remain unknown. In this study, we analyzed the anatomical structure of the rat femoral nerve, and observed the motor and sensory branches of the femoral nerve in the quadriceps femoris. After ligation of the nerves, the proximal end of the sensory nerve was connected with the distal end of the motor nerve, followed by observation of the changes in the newly-formed regenerated nerve fibers. Acetylcholinesterase staining was used to distinguish between the myelinated and unmyelinated motor and sensory nerves. Denervated muscle and newly formed nerves were compared in terms of morphology, electrophysiology and histochemistry. At 8 weeks after connection, no motor nerve fibers were observed on either side of the nerve conduit and the number of nerve fibers increased at the proximal end. The proportion of newly-formed motor and sensory fibers was different on both sides of the conduit. The area occupied by autonomic nerves in the proximal regenerative nerve was limited, but no distinct myelin sheath was visible in the distal nerve. These results confirm that sensory and motor nerves cannot be effectively connected. Moreover, the change of target organ at the distal end affects the type of nerves at the proximal end.

  1. Distance between intramuscular nerve and artery in the extraocular muscles: a preliminary immunohistochemical study using elderly human cadavers.

    Science.gov (United States)

    Kitamura, Kei; Cho, Kwang Ho; Jang, Hyung Suk; Murakami, Gen; Yamamoto, Masahito; Abe, Shin-Ichi

    2017-01-01

    Extraocular muscles are quite different from skeletal muscles in muscle fiber type and nerve supply; the small motor unit may be the most well known. As the first step to understanding the nerve-artery relationship, in this study we measured the distance from the arteriole (25-50 μm in thickness) to the nerve terminal twigs in extraocular muscles. With the aid of immunohistochemistry for nerves and arteries, we examined the arteriole-nerve distance at 10-15 sites in each of 68 extraocular muscles obtained from ten elderly cadavers. The oblique sections were nearly tangential to the muscle plate and included both global and orbital aspects of the muscle. In all muscles, the nerve twigs usually took a course parallel to muscle fibers, in contrast to most arterioles that crossed muscles. Possibly due to polyinnervation, an intramuscular nerve plexus was evident in four rectus and two oblique muscles. The arteriole-nerve distance usually ranged from 300 to 400 μm. However, individual differences were more than two times greater in each of seven muscles. Moreover, in each muscle the difference between sites sometimes reached 1 mm or more. The distance was generally shorter in the rectus and oblique muscles than in the levator palpebrae muscle, which reached statistical significance (p muscle, between muscles, and between individuals might lead to an individual biological rhythm of fatigue in oculomotor performance.

  2. Miniaurizable, High Performance, Fiber-Optic Gyroscopes for Small Satellites Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Small satellites require much lighter weight, smaller, and long life Attitude control components that can withstand stressing launch conditions and space vibration...

  3. Small Field Dosimetry Using Optical-Fiber Radioluminescence and Radpos Dosimetry Systems

    DEFF Research Database (Denmark)

    Ploquin, N.; Kertzscher Schwencke, Gustavo Adolfo Vladimir; Vandervoort, E.

    2012-01-01

    Inc, USA). The RL signal generated in the crystal by ionizing radiation can be read remotely via thin optical fiber cables. The system was originally developed for in vivo dose verification during external beam radiotherapy and brachytherapy (Radiother Oncol, 100 (3), 45662, 2011). However, due......) and GafChromic films EBT1 and EBT2 (ISP, USA). The MOSFET detectors in both mobileMOSFET and RADPOS systems were standard sensitivity μMOSFETs (TN502RDM), with a standard bias applied during irradiation. The measurements were performed in a solid water phantom at the depth of 1.5 cm and SSD = 78.5 cm...

  4. Undiagnosed Small-Fiber Polyneuropathy: Is it a Component of Gulf War Illness?

    Science.gov (United States)

    2014-09-01

    known causes of SFPN in the young (dysim- mune, genetic, and infectious ) were more common than causes of SFPN in maturity (eg, diabetes, cancer, vitamin ...fiber polyneuropathy. Accurate diagnosis of disease depends entirely on accurate definitions of the normal range. Early studies of skin neurite...under age 18 (not part of this study, but included in the analysis) are in red 4.0 5.0 6.0 7.0 0 20 40 60 80 100 Age (years) Lo g e N eu rit e D en

  5. Small arms mini-fire control system: fiber-optic barrel deflection sensor

    Energy Technology Data Exchange (ETDEWEB)

    Rajic, Slobodan [ORNL; Datskos, Panos G [ORNL

    2012-01-01

    Traditionally the methods to increase firearms accuracy, particularly at distance, have concentrated on barrel isolation (free floating) and substantial barrel wall thickening to gain rigidity. This barrel stiffening technique did not completely eliminate barrel movement but the problem was significantly reduced to allow a noticeable accuracy enhancement. This process, although highly successful, came at a very high weight penalty. Obviously the goal would be to lighten the barrel (firearm), yet achieve even greater accuracy. Thus, if lightweight barrels could ultimately be compensated for both their static and dynamic mechanical perturbations, the result would be very accurate, yet significantly lighter weight, weapons. We discuss our development of a barrel reference sensor system that is designed to accomplish this ambitious goal. Our optical fiber-based sensor monitors the barrel muzzle position and autonomously compensates for any induced perturbations. The reticle is electronically adjusted in position to compensate for the induced barrel deviation in real time.

  6. Sodium-calcium exchanger and multiple sodium channel isoforms in intra-epidermal nerve terminals

    Directory of Open Access Journals (Sweden)

    Gasser Andreas

    2010-11-01

    Full Text Available Abstract Background Nociception requires transduction and impulse electrogenesis in nerve fibers which innervate the body surface, including the skin. However, the molecular substrates for transduction and action potential initiation in nociceptors are incompletely understood. In this study, we examined the expression and distribution of Na+/Ca2+ exchanger (NCX and voltage-gated sodium channel isoforms in intra-epidermal free nerve terminals. Results Small diameter DRG neurons exhibited robust NCX2, but not NCX1 or NCX3 immunolabeling, and virtually all PGP 9.5-positive intra-epidermal free nerve terminals displayed NCX2 immunoreactivity. Sodium channel NaV1.1 was not detectable in free nerve endings. In contrast, the majority of nerve terminals displayed detectable levels of expression of NaV1.6, NaV1.7, NaV1.8 and NaV1.9. Sodium channel immunoreactivity in the free nerve endings extended from the dermal boundary to the terminal tip. A similar pattern of NCX and sodium channel immunolabeling was observed in DRG neurons in vitro. Conclusions NCX2, as well as NaV1.6, NaV1.7, NaV1.8 and NaV1.9, are present in most intra-epidermal free nerve endings. The presence of NCX2, together with multiple sodium channel isoforms, in free nerve endings may have important functional implications.

  7. Nerve injury induces the expression of syndecan-1 heparan sulfate proteoglycan in primary sensory neurons.

    Science.gov (United States)

    Murakami, K; Tanaka, T; Bando, Y; Yoshida, S

    2015-08-06

    Heparan sulfate proteoglycans (HSPGs) have important functions in development of the central nervous system; however, their functions in nerve injury are not yet fully understood. We previously reported the expression of syndecan-1, a type of HSPG, in cranial motor neurons after nerve injury, suggesting the importance of syndecan-1 in the pathology of motor nerve injury. In this study, we examined the expression of syndecan-1, a type of HSPG, in primary sensory neurons after nerve injury in mice. Sciatic nerve axotomy strongly induced the expression of syndecan-1 in a subpopulation of injured dorsal root ganglion (DRG) neurons, which were small in size and had CGRP- or isolectin B4-positive fibers. Syndecan-1 was also distributed in the dorsal horn of the spinal cord ipsilateral to the axotomy, and located on the membrane of axons in lamina II of the dorsal horn. Not only sciatic nerve axotomy, infraorbital nerve axotomy also induced the expression of syndecan-1 in trigeminal ganglion neurons. Moreover, syndecan-1 knockdown in cultured DRG neurons induced a shorter neurite extension. These results suggest that syndecan-1 expression in injured primary sensory neurons may have functional roles in nerve regeneration and synaptic plasticity, resulting in the development of neuropathic pain. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.

  8. Sodium-calcium exchanger and multiple sodium channel isoforms in intra-epidermal nerve terminals.

    Science.gov (United States)

    Persson, Anna-Karin; Black, Joel A; Gasser, Andreas; Cheng, Xiaoyang; Fischer, Tanya Z; Waxman, Stephen G

    2010-11-30

    Nociception requires transduction and impulse electrogenesis in nerve fibers which innervate the body surface, including the skin. However, the molecular substrates for transduction and action potential initiation in nociceptors are incompletely understood. In this study, we examined the expression and distribution of Na+/Ca2+ exchanger (NCX) and voltage-gated sodium channel isoforms in intra-epidermal free nerve terminals. Small diameter DRG neurons exhibited robust NCX2, but not NCX1 or NCX3 immunolabeling, and virtually all PGP 9.5-positive intra-epidermal free nerve terminals displayed NCX2 immunoreactivity. Sodium channel NaV1.1 was not detectable in free nerve endings. In contrast, the majority of nerve terminals displayed detectable levels of expression of NaV1.6, NaV1.7, NaV1.8 and NaV1.9. Sodium channel immunoreactivity in the free nerve endings extended from the dermal boundary to the terminal tip. A similar pattern of NCX and sodium channel immunolabeling was observed in DRG neurons in vitro. NCX2, as well as NaV1.6, NaV1.7, NaV1.8 and NaV1.9, are present in most intra-epidermal free nerve endings. The presence of NCX2, together with multiple sodium channel isoforms, in free nerve endings may have important functional implications.

  9. Development of a Small-Sized, Flexible, and Insertable Fiber-Optic Radiation Sensor for Gamma-Ray Spectroscopy

    Directory of Open Access Journals (Sweden)

    Wook Jae Yoo

    2015-08-01

    Full Text Available We fabricated a small-sized, flexible, and insertable fiber-optic radiation sensor (FORS that is composed of a sensing probe, a plastic optical fiber (POF, a photomultiplier tube (PMT-amplifier system, and a multichannel analyzer (MCA to obtain the energy spectra of radioactive isotopes. As an inorganic scintillator for gamma-ray spectroscopy, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce crystal was used and two solid-disc type radioactive isotopes with the same dimensions, cesium-137 (Cs-137 and cobalt-60 (Co-60, were used as gamma-ray emitters. We first determined the length of the LYSO:Ce crystal considering the absorption of charged particle energy and measured the gamma-ray energy spectra using the FORS. The experimental results demonstrated that the proposed FORS can be used to discriminate species of radioactive isotopes by measuring their inherent energy spectra, even when gamma-ray emitters are mixed. The relationship between the measured photon counts of the FORS and the radioactivity of Cs-137 was subsequently obtained. The amount of scintillating light generated from the FORS increased by increasing the radioactivity of Cs-137. Finally, the performance of the fabricated FORS according to the length and diameter of the POF was also evaluated. Based on the results of this study, it is anticipated that a novel FORS can be developed to accurately measure the gamma-ray energy spectrum in inaccessible locations such as narrow areas and holes.

  10. Development of a Small-Sized, Flexible, and Insertable Fiber-Optic Radiation Sensor for Gamma-Ray Spectroscopy.

    Science.gov (United States)

    Yoo, Wook Jae; Shin, Sang Hun; Lee, Dong Eun; Jang, Kyoung Won; Cho, Seunghyun; Lee, Bongsoo

    2015-08-28

    We fabricated a small-sized, flexible, and insertable fiber-optic radiation sensor (FORS) that is composed of a sensing probe, a plastic optical fiber (POF), a photomultiplier tube (PMT)-amplifier system, and a multichannel analyzer (MCA) to obtain the energy spectra of radioactive isotopes. As an inorganic scintillator for gamma-ray spectroscopy, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal was used and two solid-disc type radioactive isotopes with the same dimensions, cesium-137 (Cs-137) and cobalt-60 (Co-60), were used as gamma-ray emitters. We first determined the length of the LYSO:Ce crystal considering the absorption of charged particle energy and measured the gamma-ray energy spectra using the FORS. The experimental results demonstrated that the proposed FORS can be used to discriminate species of radioactive isotopes by measuring their inherent energy spectra, even when gamma-ray emitters are mixed. The relationship between the measured photon counts of the FORS and the radioactivity of Cs-137 was subsequently obtained. The amount of scintillating light generated from the FORS increased by increasing the radioactivity of Cs-137. Finally, the performance of the fabricated FORS according to the length and diameter of the POF was also evaluated. Based on the results of this study, it is anticipated that a novel FORS can be developed to accurately measure the gamma-ray energy spectrum in inaccessible locations such as narrow areas and holes.

  11. Neuro-Otological and Peripheral Nerve Involvement in Fabry Disease.

    Science.gov (United States)

    Carmona, Sergio; Weinschelbaum, Romina; Pardal, Ana; Marchesoni, Cintia; Zuberbuhler, Paz; Acosta, Patricia; Cáceres, Guillermo; Kisinovsky, Isaac; Bayón, Luciana; Reisin, Ricardo

    2017-07-18

    Fabry disease (FD) is an X-linked lysosomal storage disease, with multisystemic glycosphingolipids deposits. Neuro-otological involvement leading to hearing loss and vestibular dysfunctions has been described, but there is limited information about the frequency, site of lesion, or the relationship with peripheral neuropathy. The aim was to evaluate the presence of auditory and vestibular symptoms, and assess neurophysiological involvement of the VIII cranial nerve, correlating these findings with clinical and neurophysiological features of peripheral neuropathy. We studied 36 patients with FD with a complete neurological and neuro-otological evaluation including nerve conduction studies, quantitative sensory testing (to evaluate small fiber by warm and cold threshold detection and cold and heat pain), vestibular evoked myogenic potentials, videonistagmography, audiometry and brainstem auditory evoked potentials. Neuro-otologic symptoms included hearing loss (22.2%), vertigo (27.8%) or both (25%). An involvement of either cochlear or vestibular function was identified in most patients (75%). In 70% of our patients the involvement of both cochlear and vestibular function could not be explained by a neural or vascular mechanism. Small fiber neuropathy was identified in 77.7%. There were no significant associations between neuro-otological and QST abnormalities. Neuro-otologic involvement is frequent and most likely under-recognized in patients with FD. It lacks a specific neural or vascular pattern, suggesting multi-systemic, end organ damage. Small fiber neuropathy is an earlier manifestation of FD, but there is no correlation between the development of neuropathy and neuro-otological abnormalities.

  12. A new potential biomarker for dementia with Lewy bodies: Skin nerve α-synuclein deposits.

    Science.gov (United States)

    Donadio, Vincenzo; Incensi, Alex; Rizzo, Giovanni; Capellari, Sabina; Pantieri, Roberta; Stanzani Maserati, Michelangelo; Devigili, Grazia; Eleopra, Roberto; Defazio, Giovanni; Montini, Federico; Baruzzi, Agostino; Liguori, Rocco

    2017-07-25

    To investigate whether (1) phosphorylated α-synuclein (p-syn) deposits in skin nerves could be useful in differentiating dementia with Lewy bodies (DLB) from different forms of dementia and (2) small fiber neuropathy (SFN) is associated with DLB. We studied 18 well-characterized patients with DLB (11 with autonomic dysfunction), 23 patients with nonsynucleinopathy dementia (NSD; 13 with young-onset Alzheimer disease dementia, 6 frontotemporal dementia, and 4 vascular dementia), and 25 healthy controls. All participants underwent skin biopsies from proximal (i.e., cervical) and distal (i.e., thigh and distal leg) sites to study small nerve fibers and deposits of p-syn, considered the pathologic form of α-synuclein. No p-syn was detected in any skin sample in patients with NSD and controls but was found in all patients with DLB. SFN was found in patients with DLB and the autonomic denervation of skin was more severe in patients with autonomic dysfunctions. (1) In autonomic skin nerves, p-syn is a sensitive biomarker for DLB diagnosis, helping to differentiate DLB from other forms of dementia, although this needs to be confirmed in a larger, more representative sample; and (2) skin autonomic neuropathy is part of the DLB pathology and may contribute to autonomic symptoms. This study provides Class III evidence that p-syn in skin nerve fibers on skin biopsy accurately distinguishes DLB from other forms of dementia. © 2017 American Academy of Neurology.

  13. Análise da camada de fibras nervosas pelo GDx em pacientes pseudofácicos com opacidades da cápsula posterior Analysis of the nerve fiber layer using GDx in pseudophakic patients with posterior capsular opacification

    Directory of Open Access Journals (Sweden)

    Tatiana Azevedo Arraes

    2008-02-01

    Full Text Available OBJETIVO: Avaliar se a opacificação de cápsula posterior (OCP influenciaria na análise da camada de fibras nervosas pela polarimetria "scanning laser" (GDx. MÉTODOS: Trinta e sete pacientes pseudofácicos não glaucomatosos foram submetidos a análise da camada de fibras nervosas pelo GDx antes e após a realização de capsulotomia com Nd:YAG laser. RESULTADOS: Em cinco olhos, o GDx não conseguiu imagens aceitáveis pelos parâmetros de aquisição do aparelho. Em todos os outros, não foi observada diferença significante entre os valores médios das variáveis antes e após a realização da capsulotomia posterior. CONCLUSÃO: A presença de OCP em graus moderados e/ou quando há imagens aceitáveis em pacientes pseudofácicos não influencia o resultado da análise das imagens das fibras do nervo óptico pelo GDx. Apenas intensos graus de OCP que impeçam a obtenção de imagem analisável pelo aparelho inviabilizam o exame.PURPOSE: To evaluate if posterior capsule opacification (PCO would alter the analysis of nerve fiber layer using the scanning laser polarimetry (GDx. METHODS: Pseudophakic non-glaucomatosous eyes (37 patients underwent nerve fiber layer analysis using GDx before and after posterior capsulotomy with Nd:YAG Laser. RESULTS: In five eyes, GDx did not obtain acceptable images using the device's parameters of acquisition. In the others, mean variable values did not reach significant difference before and after posterior capsulotomy. CONCLUSION: Moderate degrees of PCO and/or acceptable images in pseudophakic patients do not alter the analysis of nerve fiber layer by GDx. Only intense degrees of PCO that hinder analyzable images make the examination impracticable.

  14. Vagus Nerve Stimulation

    Science.gov (United States)

    Howland, Robert H.

    2014-01-01

    The vagus nerve is a major component of the autonomic nervous system, has an important role in the regulation of metabolic homeostasis, and plays a key role in the neuroendocrine-immune axis to maintain homeostasis through its afferent and efferent pathways. Vagus nerve stimulation (VNS) refers to any technique that stimulates the vagus nerve, including manual or electrical stimulation. Left cervical VNS is an approved therapy for refractory epilepsy and for treatment resistant depression. Right cervical VNS is effective for treating heart failure in preclinical studies and a phase II clinical trial. The effectiveness of various forms of non-invasive transcutaneous VNS for epilepsy, depression, primary headaches, and other conditions has not been investigated beyond small pilot studies. The relationship between depression, inflammation, metabolic syndrome, and heart disease might be mediated by the vagus nerve. VNS deserves further study for its potentially favorable effects on cardiovascular, cerebrovascular, metabolic, and other physiological biomarkers associated with depression morbidity and mortality. PMID:24834378

  15. The sensory component of the facial nerve of a reptile (Lacerta viridis).

    Science.gov (United States)

    Jacobs, V L

    1979-04-01

    The sensory fibers of the facial nerve in Lacerta viridis have been studied with a silver impregnation method to follow the course of axonal degeneration. Destruction of the geniculate ganglion demonstrated the degenerated sensory component of the facial nerve adjacent to the anterior vestibular root. Within the lateral vestibular area the facial sensory fibers consist of numerous rootlets separated by vestibular fibers and cells. These rootlets may join to form a main or paired sensory tract that passes through the vestibular nuclei to enter the tractus solitarius and divide into a small ascending prefacial component and a major descending prevagal division. A few fibers continue into the postvagal part of tractus solitarius and extend caudally to terminate in the nucleus commissura infima. Prefacial fibers terminate along the periventricular gray while prevagal fibers terminate within the tractus solitarius on the dendrites of cells of nucleus tractus solitarius and near the periphery of the dorsal motor nucleus of X. There was no noticeable degeneration in the descendens tractus trigemini. Terminal degeneration to descendens nucleus trigemini and motor nucleus of VII followed the tractus solitarius course. Most facial sensory fibers are probably related to taste and other visceral information.

  16. Intercostal nerve implants transduced with an adenoviral vector encoding neurotrophin-3 promote regrowth of injured rat corticospinal tract fibers and improve hindlimb function

    NARCIS (Netherlands)

    Blits, B.; Dijkhuizen, P.A.; Boer, G. J.; Verhaagen, J.

    2000-01-01

    Following injury to central nervous tissues, damaged neurons are unable to regenerate their axons spontaneously. Implantation of peripheral nerves into the CNS, however, does result in axonal regeneration into these transplants and is one of the most powerful strategies to promote CNS regeneration.

  17. Further developments of capillary absorption spectrometers using small hollow-waveguide fibers

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, James F.; Sams, Robert L.; Blake, Thomas A.; Kriesel, Jason M.

    2014-05-01

    Our objective is to enhance quantification of stable carbon and oxygen isotope ratios to better than 1‰ relative isotope precision for sample sizes < 1 pico-mole. A newer variant Capillary Absorption Spectrometer (CAS) is described using a proprietary linear-taper hollow waveguide in conjunction with wavelength and frequency modulation techniques of tunable laser absorption spectrometry. Previous work used circular capillaries with uniform 1 mm ID to measure 13C/12C ratios with ≥ 20 pico-mole samples to ≤ 10 ppm (1‰ precision against standards) [1]. While performing fairly well, it generated residual modal noise due to multipath propagation in the hollow-waveguides (HWGs). This system has been utilized with laser ablation-catalytic combustion techniques to analyze small resolution (~ 25 μm spot diameter) laser ablation events on solids. Using smaller ID capillary waveguides could improve detection limits and spatial resolutions. Reducing an IR compatible hollow waveguide’s inner diameter (ID) to < 300 μm, reduces modal noise significantly for mid-IR operation, but feedback noise with high gain semiconductor lasers can become problematic. A proprietary linear-taper small waveguide (mean ID = 0.35 mm, L = 1 m) was tested to understand whether modal noise and optical feedback effects could be simultaneously reduced. We see better mode filtering and, significant reductions of feedback noise under favorable coupling of a multi-spatial mode QC laser to the smaller ID of the linear-tapered HWG. We demonstrate that better modal coupling operation is consistent with Liouville’s theorem, where greater suppression of feedback from spurious scatter within the HWG occurs by injecting the laser into the smaller ID port. Our progress on developing lighter weight, potentially fieldable alternatives to Isotope Ratio Mass Spectrometers (IRMS) with a small volume (≤ 0.1 cm3) CAS system will be discussed and compared to other competitive systems.

  18. Pinched Nerve

    Science.gov (United States)

    ... for pinched nerve is rest for the affected area. Nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids ... Wernicke-Korsakoff Syndrome Information Page NINDS Whiplash Information Page ...

  19. Peripheral nerve stimulation in regional anesthesia.

    Science.gov (United States)

    Klein, Stephen M; Melton, M Steve; Grill, Warren M; Nielsen, Karen C

    2012-01-01

    Peripheral nerve stimulation has a long history in regional anesthesia. Despite the advent of ultrasound-guided peripheral nerve blockade, nerve stimulation remains a popular technique used alone or, now, in combination with ultrasound-guided techniques. In light of this evolving utility of nerve stimulation, this is an appropriate time to review the basic concepts and knowledge base of this historically important tool. Electrical nerve stimulation facilitates nerve localization, using threshold current as a surrogate for needle-to-nerve distance. Preferential activation of motor nerves is possible because motor nerve fibers are more readily activated with a shorter duration of current compared with sensory nerves. The association between current and needle-to-nerve distance predicts that less current is needed to evoke a motor response as the needle moves closer to the nerve. Thus, an elicited motor response at or below 0.5 mA is considered a common end point for successful neural blockade. However, current magnitude is neither 100% sensitive nor specific. Independent of technical ability, both the biological environment and the equipment used impact the current-distance relationship. Thus, successful electrical nerve stimulation is dependent on an anesthesiologist with a solid foundation in anatomy and a thorough understanding of electrophysiology.

  20. Características estructurales del disco óptico y la capa de fibras neurorretinianas mediante tomografía confocal láser en la sospecha de cierre angular primario Structural characteristics of the optic disc and the neuroretinal nerve fiber layer observed by confocal laser tomography in suspected primary angle closure

    Directory of Open Access Journals (Sweden)

    Liamet Fernández Argones

    2012-01-01

    layer in the suspected primary angle closure, the performance of glaucomatous discriminant functions, and the influence of the optic disc size in the results. Methods: a cross-sectional case series study in 47 eyes (30 patients with suspected primary angle-closure, for which the confocal laser tomography (HRT 3, Heidelberg Engineering, Germany, was used to obtain the images. The influence of the optic disc size was analized in 3 groups: 2,0 mm². Results: the disc area was positively related to the cup area, the rim area, the cup volume, the retinal nerve fiber layer cross sectional area, and the cup size (p=0,023, p=0,009, p=0,022, p=0,026, p=0,020 respectively and negatively related with the horizontal curvature of the retinal nerve fiber layer (p=0,019. There was a significant relation to the variation of contour height (p=0,008, particularly to differences between small and medium size discs. Discriminant functions such as MRA, GPS and FSM performed better in small discs (approximately 92 % of agreement with the normal discs for each one. The RB function obtained the greater coincidence (100, 96 and 100 % for respective groups of disc areas, whereas GPS obtained the smallest (92, 72 and 55,6 % respectively. Conclusions: the disc area is related to cup area, rim area, cup volume, retinal nerve fiber layer cross sectional area, retinal nerve fiber layer horizontal curvature, cup size and the variation of contour height. The MRA, GPS and FSM discriminant functions identify better the normal optic disc when it is small. The RB function performs the best whereas the GPS performs the worst, regardless of the disc area.

  1. Estudo da camada de fibras nervosas da retina em pacientes com esquistossomose mansônica: análise com GDxTM Study of retinal nerve fiber layer in patients with schistosomiasis mansoni: analysis with GDX TM

    Directory of Open Access Journals (Sweden)

    Rodrigo Almeida Vieira Santos

    2006-12-01

    Full Text Available OBJETIVO: Estudar a camada de fibras nervosas da retina de portadores de esquistossomose mansônica hepatoesplênica. MÉTODOS: Foram submetidos ao exame com o GDx Scanning Laser System, 23 portadores de esquistossomose na forma hepatoesplênica que tinham sido submetidos, quando crianças, a esplenectomia, ligadura da veia gástrica esquerda e auto-implante de tecido esplênico no omento maior. Todos apresentaram pressão intra-ocular menor que 21 mmHg. No grupo controle foram estudados 23 indivíduos com idade e condição socioeconômico-geográfica similar, sem esquistossomose. RESULTADOS: Em apenas um paciente do grupo portador de esquistossomose foram observadas alterações em quatro parâmetros: superior nasal, média superior, média da espessura e número de fibra. Todos os indivíduos do grupo controle apresentaram GDx com parâmetros dentro da normalidade. CONCLUSÃO: No estudo realizado não foi encontrado diferença significante entre os dois grupos. Apenas um paciente mostrou redução da camada de fibras nervosas.PURPOSE: To study the retinal nerve fiber layer in young patients suffering from hepatosplenic schistosomiasis mansoni. METHODS: Twenty-three patients with hepatosplenic schistosomiasis mansoni who were submitted, when children, to splenectomy, ligature of the left gastric vein and auto-implantation of spleen tissue in the major omentum underwent GDx Scanning Laser System evaluations. All patients presented with intraocular pressure below 21 mmHg. RESULTS: Only one patient suffering from hepatosplenic schistosomiasis mansoni showed abnormalities on the GDx examination. There were no abnormalities on GDx examination in the control group. CONCLUSION: There was no significant difference between the two groups of this study. Only one patient showed retinal nerve fiber layer reduction.

  2. Comparison of diagnostic capability of macular ganglion cell complex and retinal nerve fiber layer among primary open angle glaucoma, ocular hypertension, and normal population using Fourier-domain optical coherence tomography and determining their functional correlation in In