Optic Nerve Head and Retinal Nerve Fiber Layer Differences Between Caribbean Black and African American Patients as Measured by Spectral Domain OCT.

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Rao, Rohini; Dhrami-Gavazi, Elona; Al-Aswad, Lama; Ciarleglio, Adam; Cioffi, George A; Blumberg, Dana M

2015-01-01

There are well-established differences in optic nerve morphology between patients of African and European descent. Spectral domain optical coherence tomography (OCT) scanning has demonstrated these differences with respect to optic disc area (DA), average cup-disc ratio, cup volume, and nerve fiber layer thickness. However, the term "African descent" describes a heterogenous group with considerable variability. This study evaluates differences in optic nerve and retinal nerve fiber layer (RNFL) parameters as measured by Cirrus HD-OCT between Caribbean black and African American patients. A total of 25 African American subjects and 25 Caribbean black subjects with normal ocular examinations were consecutively recruited to this study. All patients received imaging of the optic nerve and nerve fiber layer with Cirrus HD-OCT. Optic nerve and RNFL parameters were evaluated for statistically significant differences using a t test. A mixed effect model for correlated data was then created to adjust outcome variables for (1) repeated measures and (2) optic nerve size. Two one-sided t tests were then utilized to determine equivalence. After adjustment for DA, RNFL thickness, cup volume, DA, inferior nerve fiber layer, and vertical cup-disc ratio demonstrated statistically significant equivalence between the 2 groups (P value fiber layer quadrant was significantly different between the 2 groups and may merit further investigation. Findings of this study suggest that optic nerve and RNFL morphology is markedly similar between Caribbean blacks and African Americans once adjusted for optic nerve size but cannot be considered equivalent in all measures, particularly in the superior nerve fiber layer.

High-resolution imaging of retinal nerve fiber bundles in glaucoma using adaptive optics scanning laser ophthalmoscopy.

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Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Ueda-Arakawa, Naoko; Yoshida, Sachiko; Akagi, Tadamichi; Ikeda, Hanako Ohashi; Nonaka, Atsushi; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

2013-05-01

To detect pathologic changes in retinal nerve fiber bundles in glaucomatous eyes seen on images obtained by adaptive optics (AO) scanning laser ophthalmoscopy (AO SLO). Prospective cross-sectional study. Twenty-eight eyes of 28 patients with open-angle glaucoma and 21 normal eyes of 21 volunteer subjects underwent a full ophthalmologic examination, visual field testing using a Humphrey Field Analyzer, fundus photography, red-free SLO imaging, spectral-domain optical coherence tomography, and imaging with an original prototype AO SLO system. The AO SLO images showed many hyperreflective bundles suggesting nerve fiber bundles. In glaucomatous eyes, the nerve fiber bundles were narrower than in normal eyes, and the nerve fiber layer thickness was correlated with the nerve fiber bundle widths on AO SLO (P fiber layer defect area on fundus photography, the nerve fiber bundles on AO SLO were narrower compared with those in normal eyes (P optic disc, the nerve fiber bundle width was significantly lower, even in areas without nerve fiber layer defect, in eyes with glaucomatous eyes compared with normal eyes (P = .026). The mean deviations of each cluster in visual field testing were correlated with the corresponding nerve fiber bundle widths (P = .017). AO SLO images showed reduced nerve fiber bundle widths both in clinically normal and abnormal areas of glaucomatous eyes, and these abnormalities were associated with visual field defects, suggesting that AO SLO may be useful for detecting early nerve fiber bundle abnormalities associated with loss of visual function. Copyright © 2013 Elsevier Inc. All rights reserved.

Palm to Finger Ulnar Sensory Nerve Conduction.

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Davidowich, Eduardo; Nascimento, Osvaldo J M; Orsini, Marco; Pupe, Camila; Pessoa, Bruno; Bittar, Caroline; Pires, Karina Lebeis; Bruno, Carlos; Coutinho, Bruno Mattos; de Souza, Olivia Gameiro; Ribeiro, Pedro; Velasques, Bruna; Bittencourt, Juliana; Teixeira, Silmar; Bastos, Victor Hugo

2015-12-29

Ulnar neuropathy at the wrist (UNW) is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN) in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC) of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way) and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV) ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

Palm to finger ulnar sensory nerve conduction

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Eduardo Davidowich

2015-12-01

Full Text Available Ulnar neuropathy at the wrist (UNW is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

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

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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.

Retinal nerve fiber layer assessment by scanning laser polarimetry and standardized photography

NARCIS (Netherlands)

Niessen, A. G.; van den Berg, T. J.; Langerhorst, C. T.; Greve, E. L.

1996-01-01

To determine whether, in a clinical setting, scanning laser polarimetry and retinal nerve fiber layer photography provide equivalent information on the retinal nerve fiber layer. We prospectively studied 60 patients with glaucoma or ocular hypertension and 24 healthy subjects. With scanning laser

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

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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.

Nerve conduction and excitability studies in peripheral nerve disorders

DEFF Research Database (Denmark)

Krarup, Christian; Moldovan, Mihai

2009-01-01

counterparts in the peripheral nervous system, in some instances without peripheral nervous system symptoms. Both hereditary and acquired demyelinating neuropathies have been studied and the effects on nerve pathophysiology have been compared with degeneration and regeneration of axons. SUMMARY: Excitability......PURPOSE OF REVIEW: The review is aimed at providing information about the role of nerve excitability studies in peripheral nerve disorders. It has been known for many years that the insight into peripheral nerve pathophysiology provided by conventional nerve conduction studies is limited. Nerve...... excitability studies are relatively novel but are acquiring an increasingly important role in the study of peripheral nerves. RECENT FINDINGS: By measuring responses in nerve that are related to nodal function (strength-duration time constant, rheobase and recovery cycle) and internodal function (threshold...

Fish oil supplementation prevents diabetes-induced nerve conduction velocity and neuroanatomical changes in rats.

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Gerbi, A; Maixent, J M; Ansaldi, J L; Pierlovisi, M; Coste, T; Pelissier, J F; Vague, P; Raccah, D

1999-01-01

Diabetic neuropathy has been associated with a decrease in nerve conduction velocity, Na,K-ATPase activity and characteristic histological damage of the sciatic nerve. The aim of this study was to evaluate the potential effect of a dietary supplementation with fish oil [(n-3) fatty acids] on the sciatic nerve of diabetic rats. Diabetes was induced by intravenous streptozotocin injection. Diabetic animals (n = 20) were fed a nonpurified diet supplemented with either olive oil (DO) or fish oil (DM), and control animals (n = 10) were fed a nonpurified diet supplemented with olive oil at a daily dose of 0.5 g/kg by gavage for 8 wk. Nerves were characterized by their conduction velocity, morphometric analysis and membrane Na, K-ATPase activity. Nerve conduction velocity, as well as Na,K-ATPase activity, was improved by fish oil treatment. A correlation was found between these two variables (R = 0.999, P < 0.05). Moreover, a preventive effect of fish oil was observed on nerve histological damage [endoneurial edema, axonal degeneration (by 10-15%) with demyelination]. Moreover, the normal bimodal distribution of the internal diameter of myelinated fibers was absent in the DO group and was restored in the DM group. These data suggest that fish oil therapy may be effective in the prevention of diabetic neuropathy.

Human Lymphatic Mesenteric Vessels: Morphology and Possible Function of Aminergic and NPY-ergic Nerve Fibers.

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D'Andrea, Vito; Panarese, Alessandra; Taurone, Samanta; Coppola, Luigi; Cavallotti, Carlo; Artico, Marco

2015-09-01

The lymphatic vessels have been studied in different organs from a morphological to a clinical point of view. Nevertheless, the knowledge of the catecholaminergic control of the lymphatic circulation is still incomplete. The aim of this work is to study the presence and distribution of the catecholaminergic and NPY-ergic nerve fibers in the whole wall of the human mesenteric lymphatic vessels in order to obtain knowledge about their morphology and functional significance. The following experimental procedures were performed: 1) drawing of tissue containing lymphatic vessels; 2) cutting of tissue; 3) staining of tissue; 4) staining of nerve fibers; 5) histofluorescence microscopy for the staining of catecholaminergic nerve fibers; 6) staining of neuropeptide Y like-immune reactivity; 7) biochemical assay of proteins; 8) measurement of noradrenaline; 9) quantitative analysis of images; 10) statistical analysis of data. Numerous nerve fibers run in the wall of lymphatic vessels. Many of them are catecholaminergic in nature. Some nerve fibers are NPY-positive. The biochemical results on noradrenaline amounts are in agreement with morphological results on catecholaminergic nerve fibers. Moreover, the morphometric results, obtained by the quantitative analysis of images and the subsequent statistical analysis of data, confirm all our morphological and biochemical data. The knowledge of the physiological or pathological mechanism regulating the functions of the lymphatic system is incomplete. Nevertheless the catecholaminergic nerve fibers of the human mesenteric lymphatic vessels come from the adrenergic periarterial plexuses of the mesenterial arterial bed. NPY-ergic nerve fibers may modulate the microcirculatory mesenterial bed in different pathological conditions.

Ultrastructural relationships between the receptor nerve fiber and surrounding lamellae in Krause end-bulbs.

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Spassova, I

1981-01-01

The ultrastructural relationship between the receptor nerve fiber and the surrounding lamellae in Krause end-bulbs was discussed. Many sites of specialized junctions of symmetrical or asymmetrical type along the receptor nerve fiber and the surrounding lamellae were found. In addition, in close vicinity to them, spine-like digitations of the receptor nerve fiber, filled mainly with small clear vesicles, were observed. Mitochondrion-like cholinesterase-positive structures bulging in some cytoplasmic lamellae were also found. It is suggested that a functional link might exist between the specialized junctions, digitations and mitochrondrion-like structures in the transformation of external mechanical stimuli into nerve impulses.

The Association between Serum Cytokines and Damage to Large and Small Nerve Fibers in Diabetic Peripheral Neuropathy

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Francesca Magrinelli

2015-01-01

Full Text Available Diabetic peripheral neuropathy (DPN is a frequent complication of type 2 diabetes mellitus (DM and may involve small and large peripheral nerve fibers. Recent evidence suggests a role of cytokines in DPN. The paper is aimed at exploring whether the serum concentration of cytokines is associated with small and large nerve fiber function and with neuropathic pain (NP. We recruited a group of 32 type 2 DM patients who underwent serum cytokines (TNF-α, IL-2, IL-4, IL-6, and IL-10 dosage as well as electrodiagnostic and quantitative sensory testing (QST assessment to explore damage to large and small nerve fibers. Raised serum levels of IL-6 and IL-10 correlated with markers of large nerve fiber sensory and motor axonal damage. Raised IL-10 serum level was associated with signs of motor nerve demyelination. No differences were found in pain characteristics and electrodiagnostic and QST markers of small nerve fiber function in relation to cytokines serum levels. IL-6 and IL-10 serum levels were associated with large nerve fiber damage but not to small fibers function or NP. IL-6 and IL-10 cytokines might play a role in the pathogenesis of nerve fiber damage or represent a compensatory or neuroprotective mechanism.

Comparisons of retinal nerve fiber layer thickness changes after macular hole surgery

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Nelson Chamma Capelanes

Full Text Available ABSTRACT Purpose: To compare postoperative changes in retinal nerve fiber layer thickness in patients with macular holes treated with vitrectomy with Brilliant Blue-assisted internal limiting membrane peeling. Methods: Twenty-two eyes of 20 patients with macular holes were studied. Each eye was selected to undergo Brilliant Blue-assisted internal limiting membrane peeling. The circumferential retinal nerve fiber layer thickness was determined using spectral domain optical coherence tomography preoperatively and 2 months postoperatively. Mean overall and sectoral retinal nerve fiber layer thicknesses were obtained for each patient. Results: There was no statistically significant difference (p≥0.05 between the pre- and post-treatment measurements in relation to each CFN variable, i.e., on average, pre-treatment measures were the same as post-treatment measures. Furthermore, despite the differences between the pre- and post-treatment measures always being positive (pre-post >0, they are not statistically significant. Conclusions: This study showed no significant decrease in retinal nerve fiber layer thickness measurements after macular holes surgery, regardless of age or sex.

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

Peripapillary retinal nerve fiber layer and choroidal thickness in cirrhosis patients

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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.

Chitin biological absorbable catheters bridging sural nerve grafts transplanted into sciatic nerve defects promote nerve regeneration.

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Wang, Zhi-Yong; Wang, Jian-Wei; Qin, Li-Hua; Zhang, Wei-Guang; Zhang, Pei-Xun; Jiang, Bao-Guo

2018-06-01

To investigate the efficacy of chitin biological absorbable catheters in a rat model of autologous nerve transplantation. A segment of sciatic nerve was removed to produce a sciatic nerve defect, and the sural nerve was cut from the ipsilateral leg and used as a graft to bridge the defect, with or without use of a chitin biological absorbable catheter surrounding the graft. The number and morphology of regenerating myelinated fibers, nerve conduction velocity, nerve function index, triceps surae muscle morphology, and sensory function were evaluated at 9 and 12 months after surgery. All of the above parameters were improved in rats in which the nerve graft was bridged with chitin biological absorbable catheters compared with rats without catheters. The results of this study indicate that use of chitin biological absorbable catheters to surround sural nerve grafts bridging sciatic nerve defects promotes recovery of structural, motor, and sensory function and improves muscle fiber morphology. © 2018 John Wiley & Sons Ltd.

Selective Fiber Degeneration in the Peripheral Nerve of a Patient With Severe Complex Regional Pain Syndrome

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Adrien Yvon

2018-04-01

Full Text Available Aims: Complex regional pain syndrome (CRPS is characterized by chronic debilitating pain disproportional to the inciting event and accompanied by motor, sensory, and autonomic disturbances. The pathophysiology of CRPS remains elusive. An exceptional case of severe CRPS leading to forearm amputation provided the opportunity to examine nerve histopathological features of the peripheral nerves.Methods: A 35-year-old female developed CRPS secondary to low voltage electrical injury. The CRPS was refractory to medical therapy and led to functional loss of the forelimb, repeated cutaneous wound infections leading to hospitalization. Specifically, the patient had exhausted a targeted conservative pain management programme prior to forearm amputation. Radial, median, and ulnar nerve specimens were obtained from the amputated limb and analyzed by light and transmission electron microscopy (TEM.Results: All samples showed features of selective myelinated nerve fiber degeneration (47–58% of fibers on electron microscopy. Degenerating myelinated fibers were significantly larger than healthy fibers (p < 0.05, and corresponded to the larger Aα fibers (motor/proprioception whilst smaller Aδ (pain/temperature fibers were spared. Groups of small unmyelinated C fibers (Remak bundles also showed evidence of degeneration in all samples.Conclusions: We are the first to show large fiber degeneration in CRPS using TEM. Degeneration of Aα fibers may lead to an imbalance in nerve signaling, inappropriately triggering the smaller healthy Aδ fibers, which transmit pain and temperature. These findings suggest peripheral nerve degeneration may play a key role in CRPS. Improved knowledge of pathogenesis will help develop more targeted treatments.

Spatial clustering analysis in neuroanatomy: Applications of different approaches to motor nerve fiber distribution

NARCIS (Netherlands)

Crunelli, V.; Prodanov, D.P.; Nagelkerke, Nico; Marani, Enrico

2007-01-01

Spatial organization of the nerve fibers in the peripheral nerves may be important for the studies of axonal regeneration, the degenerative nerve diseases and the construction of interfaces with peripheral nerves, such as nerve prostheses. Functional topography of motor axons related to the

On the nature of the afferent fibers of oculomotor nerve.

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Manni, E; Draicchio, F; Pettorossi, V E; Carobi, C; Grassi, S; Bortolami, R; Lucchi, M L

1989-03-01

The oculogyric nerves contain afferent fibers originating from the ophthalmic territory, the somata of which are located in the ipsilateral semilunar ganglion. These primary sensory neurons project to the Subnucleus Gelatinosus of the Nucleus Caudalis Trigemini, where they make presynaptic contact with the central endings of the primary trigeminal afferents running in the fifth cranial nerve. After complete section of the trigeminal root, the antidromic volleys elicited in the trunk of the third cranial nerve by stimulating SG of NCT consisted of two waves belonging to the A delta and C groups. The area of both components of the antidromic volleys decreased both after bradykinin and hystamine injection into the corresponding cutaneous region and after thermic stimulation of the ipsilateral trigeminal ophthalmic territory. The reduction of such potentials can be explained in terms of collision between the antidromic volleys and those elicited orthodromically by chemical and thermic stimulation. Also, capsaicin applied on the nerve induced an immediate increase, followed by a long lasting decrease, of orthodromic evoked response area. These findings bring further support to the nociceptive nature of the afferent fibers running into the oculomotor nerve.

Energy-optimal electrical excitation of nerve fibers.

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Jezernik, Saso; Morari, Manfred

2005-04-01

We derive, based on an analytical nerve membrane model and optimal control theory of dynamical systems, an energy-optimal stimulation current waveform for electrical excitation of nerve fibers. Optimal stimulation waveforms for nonleaky and leaky membranes are calculated. The case with a leaky membrane is a realistic case. Finally, we compare the waveforms and energies necessary for excitation of a leaky membrane in the case where the stimulation waveform is a square-wave current pulse, and in the case of energy-optimal stimulation. The optimal stimulation waveform is an exponentially rising waveform and necessitates considerably less energy to excite the nerve than a square-wave pulse (especially true for larger pulse durations). The described theoretical results can lead to drastically increased battery lifetime and/or decreased energy transmission requirements for implanted biomedical systems.

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

Retinal Nerve Fiber Layer Protrusion Associated with Tilted Optic Discs.

Science.gov (United States)

Chiang, Jaclyn; Yapp, Michael; Ly, Angelica; Hennessy, Michael P; Kalloniatis, Michael; Zangerl, Barbara

2018-03-01

This study resulted in the identification of an optic nerve head (ONH) feature associated with tilted optic discs, which might potentially contribute to ONH pathologies. Knowledge of such findings will enhance clinical insights and drive future opportunities to understand disease processes related to tilted optic discs. The aim of this study was to identify novel retinal nerve fiber layer (RNFL) anomalies by evaluating tilted optic discs using optical coherence tomography. An observed retinal nerve fiber protrusion was further investigated for association with other morphological or functional parameters. A retrospective review of 400 randomly selected adult patients with ONH examinations was conducted in a referral-only, diagnostic imaging center. After excluding other ONH pathologies, 215 patients were enrolled and evaluated for optic disc tilt and/or torsion. Gross anatomical ONH features, including size and rim or parapapillary region elevation, were assessed with stereoscopic fundus photography. Optical coherence tomography provided detailed morphological information of individual retinal layers. Statistical analysis was applied to identify significant changes between individual patient cohorts. A dome-shaped hyperreflective RNFL bulge, protruding into the neurosensory retina at the optic disc margins, was identified in 17 eyes with tilted optic discs. Available follow-up data were inconclusive regarding natural changes with this ONH feature. This RNFL herniation was significantly correlated with smaller than average optic disc size (P = .005), congenital disc tilt (P optic discs, which has not previously been assessed as an independent ONH structure. The feature is predominantly related to congenital crowded, small optic discs and variable between patients. This study is an important first step to elucidate diagnostic capabilities of tilted disc morphological changes and understanding associated functional deficits.

Compound sensory action potential in normal and pathological human nerves

DEFF Research Database (Denmark)

Krarup, Christian

2004-01-01

The compound sensory nerve action potential (SNAP) is the result of phase summation and cancellation of single fiber potentials (SFAPs) with amplitudes that depend on fiber diameter, and the amplitude and shape of the SNAP is determined by the distribution of fiber diameters. Conduction velocities...... dispersion over increasing conduction distance is greater for the SNAP than CMAP, and demonstration of conduction block is therefore difficult. In addition, the effect of temporal dispersion on amplitude and shape is strongly dependent on the number of conducting fibers and their distribution, and......, with fiber loss or increased conduction velocity variability changes of the SNAP may be smaller than expected from normal nerve. The biophysical characteristics of sensory and motor fibers differ, and this may to some extent determine divergent pathophysiological changes in sensory and motor fibers...

Diagnostic value of the near-nerve needle sensory nerve conduction in sensory inflammatory demyelinating polyneuropathy.

Science.gov (United States)

Odabasi, Zeki; Oh, Shin J

2018-03-01

In this study we report the diagnostic value of the near-nerve needle sensory nerve conduction study (NNN-SNCS) in sensory inflammatory demyelinating polyneuropathy (IDP) in which the routine nerve conduction study was normal or non-diagnostic. The NNN-SNCS was performed to identify demyelination in the plantar nerves in 14 patients and in the median or ulnar nerve in 2 patients with sensory IDP. In 16 patients with sensory IDP, routine NCSs were either normal or non-diagnostic for demyelination. Demyelination was identified by NNN-SNCS by dispersion and/or slow nerve conduction velocity (NCV) below the demyelination marker. Immunotherapy was initiated in 11 patients, 10 of whom improved or remained stable. NNN-SNCS played an essential role in identifying demyelinaton in 16 patients with sensory IDP, leading to proper treatment. Muscle Nerve 57: 414-418, 2018. © 2017 Wiley Periodicals, Inc.

Nerve fibers and menstrual cycle in peritoneal endometriosis.

Science.gov (United States)

Wang, Guoyun; Tokushige, Natsuko; Fraser, Ian S

2011-06-30

There was no difference in the density of nerve fibers across the menstrual cycle in peritoneal endometriotic lesions. These findings may explain why patients with peritoneal endometriosis often have painful symptoms throughout the menstrual cycle. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Short-term observations of the regenerative potential of injured proximal sensory nerves crossed with distal motor nerves

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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.

Effect of hip and knee position on nerve conduction in the common fibular nerve.

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Broadhurst, Peter Kaas; Robinson, Lawrence R

2017-09-01

The aim of this study was to measure the influence that hip and knee position have on routine fibular motor nerve conduction studies. Healthy subjects under age 40 were recruited (n = 24) to have fibular nerve conduction studies completed in various positions, using hip extension-knee extension as a control. A mean increase in conduction velocity of 2.5 m/s across the knee (P = 0.020) was seen during hip flexion compared with hip extension. A mean decrease in velocity of 1.6 m/s through the leg segment (P = 0.016) was seen during knee flexion compared with knee extension. This study shows that the optimal position of the leg during fibular nerve studies is with the hip in flexion and knee in extension, to more accurately reflect nerve length for velocity calculations. This may have implications for other peripheral nerves with respect to proximal joint position affecting calculated velocity. Muscle Nerve 56: 519-521, 2017. © 2017 Wiley Periodicals, Inc.

Median Nerve Conduction in Healthy Nigerians: Normative Data

African Journals Online (AJOL)

of median nerve disease using multiple studies, and rendering ... Aim: To develop normative values for motor and sensory median nerve ..... Table 5: Comparison of median motor nerve conduction study parameters to studies elsewhere. Study.

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

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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.

Occurrence of substance P-like immunoreactive nerve fibers in Krause corpuscles of the dog's tongue.

Science.gov (United States)

Ichikawa, H; Nishikawa, S; Wakisaka, S; Matsuo, S; Takano, Y; Akai, M

1988-01-01

Substance P-like immunoreactive (SPLI) nerve fibers were demonstrated in the Krause corpuscles of the dog's tongue using the indirect immunofluorescence method and cholinesterase histochemistry. SPLI nerve fibers were often in contact with Krause end bulbs and occasionally entered them. From this result it was suggested that substance P might be involved in sensory mechanism of the Krause apparatus.

Brain imaging signatures of the relationship between epidermal nerve fibers and heat pain perception.

Science.gov (United States)

Tseng, Ming-Tsung; Kong, Yazhuo; Chiang, Ming-Chang; Chao, Chi-Chao; Tseng, Wen-Yih I; Hsieh, Sung-Tsang

2015-11-15

Although the small-diameter primary afferent fibers in the skin promptly respond to nociceptive stimuli and convey sensory inputs to the central nervous system, the neural signatures that underpin the relationship between cutaneous afferent fibers and pain perception remain elusive. We combined skin biopsy at the lateral aspect of the distal leg, which is used to quantify cutaneous afferent fibers, with fMRI, which is used to assess brain responses and functional connectivity, to investigate the relationship between cutaneous sensory nerves and the corresponding pain perception in the brain after applying heat pain stimulation to the dorsum of the right foot in healthy subjects. During painful stimulation, the degree of cutaneous innervation, as measured by epidermal nerve fiber density, was correlated with individual blood oxygen level-dependent (BOLD) signals of the posterior insular cortex and of the thalamus, periaqueductal gray, and rostral ventromedial medulla. Pain perception was associated with the activation of the anterior insular cortex and with the functional connectivity from the anterior insular cortex to the primary somatosensory cortex during painful stimulation. Most importantly, both epidermal nerve fiber density and activity in the posterior insular cortex showed a positive correlation with the strength of coupling under pain between the anterior insular cortex and the primary somatosensory cortex. Thus, our findings support the notion that the neural circuitry subserving pain perception interacts with the cerebral correlates of peripheral nociceptive fibers, which implicates an indirect role for skin nerves in human pain perception. Copyright © 2015 Elsevier Inc. All rights reserved.

Scanning laser polarimetry retinal nerve fiber layer thickness measurements after LASIK.

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Zangwill, Linda M; Abunto, Teresa; Bowd, Christopher; Angeles, Raymund; Schanzlin, David J; Weinreb, Robert N

2005-02-01

To compare retinal nerve fiber layer (RNFL) thickness measurements before and after LASIK. Cohort study. Twenty participants undergoing LASIK and 14 normal controls. Retinal nerve fiber layer thickness was measured before LASIK and approximately 3 months after surgery in one eye each of 20 patients using a scanning laser polarimeter (GDx Nerve Fiber Analyzer) with fixed corneal compensation (FCC), one with variable corneal compensation (GDx VCC), and optical coherence tomography (OCT). Fourteen normal controls also were tested at baseline and approximately 3 months later. Retinal nerve fiber layer thicknesses measured with the GDx FCC, GDx VCC, and OCT. At baseline, mean (95% confidence interval [CI]) RNFL thicknesses for the GDx FCC, GDx VCC, and OCT were 78.1 microm (72.2-83.9), 54.3 microm (52.7-56.0), and 96.8 microm (93.2-100.5), respectively. In both LASIK and control groups, there were no significant changes between baseline and follow-up examinations in GDx VCC and OCT RNFL thickness measurements globally or in the superior and inferior quadrants (mean change, FCC measurements between baseline and follow-up. In LASIK patients, significant reductions were observed in GDx FCC RNFL measurements. Average absolute values of the mean (95% CI) change in thickness were 12.4 microm (7.7-17.2), 15.3 microm (9.6-20.9), and 12.9 microm (7.6-18.1) for GDx FCC RNFL measurements superiorly, inferiorly, and globally, respectively (all Ps FCC RNFL thickness measurements after LASIK is a measurement artifact and is most likely due to erroneous compensation for corneal birefringence. With scanning laser polarimetry, it is mandatory to compensate individually for change in corneal birefringence after LASIK to ensure accurate RNFL assessment.

Effect of duration and severity of migraine on retinal nerve fiber layer, ganglion cell layer, and choroidal thickness.

Science.gov (United States)

Abdellatif, Mona K; Fouad, Mohamed M

2018-03-01

To investigate the factors in migraine that have the highest significance on retinal and choroidal layers' thickness. Ninety patients with migraine and 40 age-matched healthy participants were enrolled in this observational, cross-sectional study. After full ophthalmological examination, spectral domain-optical coherence tomography was done for all patients measuring the thickness of ganglion cell layer and retinal nerve fiber layer. Enhanced depth imaging technique was used to measure the choroidal thickness. There was significant thinning in the superior and inferior ganglion cell layers, all retinal nerve fiber layer quadrants, and all choroidal quadrants (except for the central subfield) in migraineurs compared to controls. The duration of migraine was significantly correlated with ganglion cell layer, retinal nerve fiber layer, and all choroidal quadrants, while the severity of migraine was significantly correlated with ganglion cell layer and retinal nerve fiber layer only. Multiregression analysis showed that the duration of migraine is the most important determinant factor of the superior retinal nerve fiber layer quadrant (β = -0.375, p = 0.001) and in all the choroidal quadrants (β = -0.531, -0.692, -0.503, -0.461, -0.564, respectively, p  layer quadrants (β = -0.256, -0.335, -0.308; p  = 0.036, 0.005, 0.009, respectively) and the inferior ganglion cell layer hemisphere (β = -0.377 and p = 0.001). Ganglion cell layer, retinal nerve fiber layer, and choroidal thickness are significantly thinner in patients with migraine. The severity of migraine has more significant influence in the thinning of ganglion cell layer and retinal nerve fiber layer, while the duration of the disease affected the choroidal thickness more.

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

African Journals Online (AJOL)

hydroxytryptamine) immunoreactivity in the pyloric mucosa of the rat stomach. The immunoreactive elements included the endocrine cells, mast cells and mucosal nerve fibers in the lamina propria. The immunopositive endocrine cells were oval in ...

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

included 41 patients with unilateral optic neuritis and 19 healthy volunteers. All patients were evaluated and examined within 28 days of onset of symptoms. The peripapillary retinal nerve fiber layer thickness (RNFLT), an objective quantitative measure of optic nerve head edema, was measured by optical...... 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......BACKGROUND: Acute optic neuritis occurs with and without papillitis. The presence of papillitis has previously been thought to imply an anterior location of the neuritis, but imaging studies seeking to test this hypothesis have been inconclusive. METHODS: This prospective observational cohort study...

A pilot study to evaluate the clinical relevance of endometriosis-associated nerve fibers in peritoneal endometriotic lesions.

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Mechsner, Sylvia; Kaiser, Andrea; Kopf, Andreas; Gericke, Christine; Ebert, Andreas; Bartley, Julia

2009-12-01

To investigate the clinical relevance of endometriosis-associated nerve fibers in the development of endometriosis-associated symptoms. Prospective nonrandomized study. University hospital endometriosis center. Fifty-one premenopausal patients underwent surgical laparoscopy because of chronic pelvic pain, dysmenorrhea, or for ovarian cysts. Endometriosis was diagnosed in 44 patients. The preoperative and postoperative pain scores were determined using a standardized questionnaire with a visual analogue scale from 1-10. Patients with peritoneal endometriosis were divided into two groups depending on their preoperative pain score: group A with a pain score of at least 3 or more and group B with a pain score of 2 or less. Patients without peritoneal endometriosis were classified as group C and patients without endometriosis were classified as group D. Immunohistochemical analysis of neurofilament and protein gene product 9.5 were used for nerve fiber detection. Occurrence of endometriosis-associated nerve fibers was correlated with the severity of pelvic pain and/or dysmenorrhea. Peritoneal endometriosis-associated nerve fibers were found significantly more frequently in group A than in group B (82.6% vs. 33.3%). The present study suggests that the presence of endometriosis-associated nerve fibers in the peritoneum is important for the development of endometriosis-associated pelvic pain and dysmenorrhea.

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

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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.

MR tractography; Visualization of structure of nerve fiber system from diffusion weighted images with maximum intensity projection method

Energy Technology Data Exchange (ETDEWEB)

Kinosada, Yasutomi; Okuda, Yasuyuki (Mie Univ., Tsu (Japan). School of Medicine); Ono, Mototsugu (and others)

1993-02-01

We developed a new noninvasive technique to visualize the anatomical structure of the nerve fiber system in vivo, and named this technique magnetic resonance (MR) tractography and the acquired image an MR tractogram. MR tractography has two steps. One is to obtain diffusion-weighted images sensitized along axes appropriate for depicting the intended nerve fibers with anisotropic water diffusion MR imaging. The other is to extract the anatomical structure of the nerve fiber system from a series of diffusion-weighted images by the maximum intensity projection method. To examine the clinical usefulness of the proposed technique, many contiguous, thin (3 mm) coronal two-dimensional sections of the brain were acquired sequentially in normal volunteers and selected patients with paralyses, on a 1.5 Tesla MR system (Signa, GE) with an ECG-gated Stejskal-Tanner pulse sequence. The structure of the nerve fiber system of normal volunteers was almost the same as the anatomy. The tractograms of patients with paralyses clearly showed the degeneration of nerve fibers and were correlated with clinical symptoms. MR tractography showed great promise for the study of neuroanatomy and neuroradiology. (author).

Effect of diabetic retinopathy and panretinal photocoagulation on retinal nerve fiber layer and optic nerve appearance.

Science.gov (United States)

Lim, Michele C; Tanimoto, Suzana A; Furlani, Bruno A; Lum, Brent; Pinto, Luciano M; Eliason, David; Prata, Tiago S; Brandt, James D; Morse, Lawrence S; Park, Susanna S; Melo, Luiz A S

2009-07-01

To determine if panretinal photocoagulation (PRP) alters retinal nerve fiber layer (RNFL) thickness and optic nerve appearance. Patients with diabetes who did and did not undergo PRP and nondiabetic control subjects were enrolled in a prospective study. Participants underwent optical coherence tomography of the peripapillary retina and optic nerve. Stereoscopic optic nerve photographs were graded in a masked fashion. Ninety-four eyes of 48 healthy individuals, 89 eyes of 55 diabetic patients who did not undergo PRP, and 37 eyes of 24 subjects with diabetes who underwent PRP were included in this study. Eyes that had been treated with PRP had thinner peripapillary RNFL compared with the other groups; this was statistically significantly different in the inferior (P = .004) and nasal (P = .003) regions. Optic nerve cupping did not increase with severity of disease classification, but the proportion of optic nerves graded as suspicious for glaucoma or as having nonglaucomatous optic neuropathy did (P = .008). These grading categories were associated with thinner RNFL measurements. Diabetic eyes that have been treated with PRP have thinner RNFL than nondiabetic eyes. Optic nerves in eyes treated with PRP are more likely to be graded as abnormal, but their appearance is not necessarily glaucomatous and may be related to thinning of the RNFL.

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

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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.

Neura, nerves, nerve fibers, neurofibrils, microtubules: multidimensional routes of pain, pleasure, and voluntary action in images across the ages.

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Frixione, Eugenio

2013-01-01

Available records indicate that the human body has always been conceived, in different periods and cultures, as spanned by multiple channels for internal communication and coherent functioning as a unit-"meridians" in treatises of Chinese medicine, metu in Egyptian papyri, srotas in Ayurvedic Indian texts, and neura in the Western scientific heritage from ancient Greece. Unfortunately, the earliest extant figurative depictions of such pathways of general control, complementary to the blood vessels, are late medieval copies of old crude sketches that attempted to show the main anatomico-physiological systems. The scarcity of adequate illustrations was more than compensated in the Renaissance, when the efforts of both artists and anatomists for the first time produced basically correct renditions of the human nervous system and many other bodily structures. As attention was next focused on microscopic structure as a requisite to understand physiological mechanisms, during the Enlightenment the nerves were revealed to consist of numerous thin tubes or fibers aligned in parallel. Improved microscopy techniques in the nineteenth century led to discovering and delineating still finer fibrils coursing along the cores of the nerve fibers themselves. Electron microscopy, developed throughout the twentieth century, recognized some of these fibrils within nerve fibers as being also tubular. All the progressive stages in understanding nerve construction, at increasingly more detailed scales, have been accompanied by technological advances and by debate about the structure and function relationship. And every step has been a source of amazing imagery. © 2013 Elsevier B.V. All rights reserved.

Diffusion tensor imaging for nerve fiber bundles in the brain stem and spinocerebellar degeneration

International Nuclear Information System (INIS)

Honma, Tsuguo

2009-01-01

Diffusion tensor imaging (DTI) can create an image of the anisotropic nature of diffusion and express it quantitatively. Nerve fibers have a large anisotropic diffusion, and it is possible to obtain images of the nerve fiber bundle. The purpose of this study is to observe the nerve fiber bundles in the brain stem using DTI and study its potential for diagnosing the type of spinocerebellar degeneration (SCD). Fractional anisotropy (FA) maps and 3D-tractography images were obtained for 41 subjects with no brain stem abnormalities. We created an apparent diffusion coefficient (ADC) map and an FA map using DTI for 16 subjects in the disease group (11 with hereditary SCD and 5 with non-hereditary SCD) and 25 in the control group. The diffusion value of the pons and middle cerebellar peduncle was measured using ADC, and the degree of anisotropic diffusion was measured using FA. The pyramidal tract, superior cerebellar peduncle, and inferior cerebellar peduncle were clearly demonstrated for all cases. ADC for the middle cerebellar peduncle in spinocerebellar ataxin (SCA)1 was significantly higher, similar to that for the pons in dentatorubro-pallidoluysian atrophy (DRPLA). In MSA-C, ADC for both the pons and middle cerebellar peduncle was significantly elevated and FA was significantly decreased. There were no significant changes in SCA3. We could observe the nerve fiber bundles in the brain stem using DTI. FA and ADC measurements with DTI can aid in diagnosing the type of SCD. (author)

Electrodiagnosis and nerve conduction studies.

Science.gov (United States)

Posuniak, E A

1984-08-01

The use of electrodiagnostic techniques in evaluation of complaints in the lower extremities provides an objective method of assessment. A basic understanding of principles of neurophysiology, EMG and NCV methodology, and neuropathology of peripheral nerves greatly enhances physical diagnosis and improves the state of the art in treatment of the lower extremity, especially foot and ankle injuries. Familiarity with the method of reporting electrodiagnostic studies and appreciation of the electromyographer's interpretation of the EMG/NCV studies also reflects an enhanced fund of knowledge, skills, and attitudes as pertains to one's level of professional expertise. Information regarding the etiology of positive sharp waves, fibrillation potentials, fasciculation, and normal motor action potentials and conduction studies serves as a sound basis for the appreciation of the categories of nerve injury. Competence in understanding the degree of axonal or myelin function or dysfunction in a nerve improve one's effectiveness not only in medical/surgical treatment but in prognostication of recovery of function. A review of the entrapment syndromes in the lower extremity with emphasis on tarsal tunnel syndrome summarizes the most common nerve entrapments germane to the practice of podiatry. With regard to tarsal tunnel syndrome, the earliest electrodiagnostic study to suggest compression was reported to be the EMG of the foot and leg muscles, even before prolonged nerve latency was noted.

Anoxia increases potassium conductance in hippocampal nerve cells.

Science.gov (United States)

Hansen, A J; Hounsgaard, J; Jahnsen, H

1982-07-01

The effect of anoxia on nerve cell function was studied by intra- and extracellular microelectrode recordings from the CA1 and CA3 region in guinea pig hippocampal slices. Hyperpolarization and concomitant reduction of the nerve cell input resistance was observed early during anoxia. During this period the spontaneous activity first disappeared, then the evoked activity gradually disappeared. The hyperpolarization was followed by depolarization and an absence of a measurable input resistance. All the induced changes were reversed when the slice was reoxygenated. Reversal of the electro-chemical gradient for Cl- across the nerve cell membrane did not affect the course of events during anoxia. Aminopyridines blocked the anoxic hyperpolarization and attenuated the decrease of membrane resistance, but had no effect on the later depolarization. Blockers of synaptic transmission. Mn++, Mg++ and of Na+-channels (TTX) were without effect on the nerve cell changes during anoxia. It is suggested that the reduction of nerve cell excitability in anoxia is primarily due to increased K+-conductance. Thus, the nerve cells are hyperpolarized and the input resistance reduced, causing higher threshold and reduction of synaptic potentials. The mechanism of the K+-conductance activation is unknown at present.

Genetic analysis of peripheral nerve conduction velocity in twins

NARCIS (Netherlands)

Rijsdijk, F.V.; Boomsma, D.I.; Vernon, P.A.

1995-01-01

We studied variation in peripheral nerve conduction velocity (PNCV) and intelligence in a group of 16-year-old Dutch twins. It has been suggested that both brain nerve conduction velocity and PNCV are positively correlated with intelligence (Reed, 1984) and that heritable differences in NCV may

Whole plantar nerve conduction study with disposable strip electrodes.

Science.gov (United States)

Hemmi, Shoji; Kurokawa, Katsumi; Nagai, Taiji; Okamoto, Toshio; Murakami, Tatsufumi; Sunada, Yoshihide

2016-02-01

A new method to evaluate whole plantar nerve conduction with disposable strip electrodes (DSEs) is described. Whole plantar compound nerve action potentials (CNAPs) were recorded at the ankle. DSEs were attached to the sole for simultaneous stimulation of medial and lateral plantar nerves. We also conducted medial plantar nerve conduction studies using an established method and compared the findings. Whole plantar CNAPs were recorded bilaterally from 32 healthy volunteers. Mean baseline to peak amplitude for CNAPs was 26.9 ± 11.8 μV, and mean maximum conduction velocity was 65.8 ± 8.3 m/s. The mean amplitude of CNAPs obtained by our method was 58.2% higher than that of CNAPs obtained by the Saeed method (26.9 μV vs. 17.0 μV; P < 0.0001). The higher mean amplitude of whole plantar CNAPs obtained by our method suggests that it enables CNAPs to be obtained easily, even in elderly people. © 2015 Wiley Periodicals, Inc.

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.

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...... of these fibers also responded to low-frequency sound. 5) The vibration-sensitive fibers in the anterior branch probably innervated the sacculus and the utriculus. 6) Hence, the grassfrog has at least two, and probably three, vibration-sensitive organs in the inner ear. 7) All fibers had V-shaped vibrational...... tuning curves. In the posterior branch best frequencies (BFs) ranged from 10 to 300 Hz, in the anterior branch from 10 to 100 Hz. In the posterior branch spike-rate thresholds at BF ranged from 0.04 to 1.28 cm/s2, in the anterior branch from 0.02 to 1.28 cm/s2. All fibers showed strong synchronization...

Survey of Nerve Fiber Layer Thickness in Anisometropic and Strabismic Amblyopia

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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.

Optic Nerve Imaging

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... News About Us Donate In This Section Optic Nerve Imaging email Send this article to a friend ... measurements of nerve fiber damage (or loss). The Nerve Fiber Analyzer (GDx) uses laser light to measure ...

Taste bud-derived BDNF maintains innervation of a subset of TrkB-expressing gustatory nerve fibers.

Science.gov (United States)

Tang, Tao; Rios-Pilier, Jennifer; Krimm, Robin

2017-07-01

Taste receptor cells transduce different types of taste stimuli and transmit this information to gustatory neurons that carry it to the brain. Taste receptor cells turn over continuously in adulthood, requiring constant new innervation from nerve fibers. Therefore, the maintenance of innervation to taste buds is an active process mediated by many factors, including brain-derived neurotrophic factor (BDNF). Specifically, 40% of taste bud innervation is lost when Bdnf is removed during adulthood. Here we speculated that not all gustatory nerve fibers express the BDNF receptor, TrkB, resulting in subsets of neurons that vary in their response to BDNF. However, it is also possible that the partial loss of innervation occurred because the Bdnf gene was not effectively removed. To test these possibilities, we first determined that not all gustatory nerve fibers express the TrkB receptor in adult mice. We then verified the efficiency of Bdnf removal specifically in taste buds of K14-CreER:Bdnf mice and found that Bdnf expression was reduced to 1%, indicating efficient Bdnf gene recombination. BDNF removal resulted in a 55% loss of TrkB-expressing nerve fibers, which was greater than the loss of P2X3-positive fibers (39%), likely because taste buds were innervated by P2X3+/TrkB- fibers that were unaffected by BDNF removal. We conclude that gustatory innervation consists of both TrkB-positive and TrkB-negative taste fibers and that BDNF is specifically important for maintaining TrkB-positive innervation to taste buds. In addition, although taste bud size was not affected by inducible Bdnf removal, the expression of the γ subunit of the ENaC channel was reduced. So, BDNF may regulate expression of some molecular components of taste transduction pathways. Copyright © 2017. Published by Elsevier Inc.

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

thresholds from 0.02 cm/s2. The sound and vibration sensitivity was compared for each fiber using the offset between the rate-level curves for sound and vibration stimulation as a measure of relative vibration sensitivity. When measured in this way relative vibration sensitivity decreases with frequency from......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......, 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...

Comparison of Nerve Excitability Testing, Nerve Conduction Velocity, and Behavioral Observations for Acrylamide Induced Peripheral Neuropathy

Science.gov (United States)

Nerve excitability (NE) testing is a sensitive method to test for peripheral neurotoxicity in humans,and may be more sensitive than compound nerve action potential (CNAP) or nerve conduction velocity (NCV).We used acrylamide to compare the NE and CNAP/NCV methods. Behavioral test...

Specific paucity of unmyelinated C-fibers in cutaneous peripheral nerves of the African naked-mole rat: comparative analysis using six species of Bathyergidae.

Science.gov (United States)

St John Smith, Ewan; Purfürst, Bettina; Grigoryan, Tamara; Park, Thomas J; Bennett, Nigel C; Lewin, Gary R

2012-08-15

In mammalian peripheral nerves, unmyelinated C-fibers usually outnumber myelinated A-fibers. By using transmission electron microscopy, we recently showed that the saphenous nerve of the naked mole-rat (Heterocephalus glaber) has a C-fiber deficit manifested as a substantially lower C:A-fiber ratio compared with other mammals. Here we determined the uniqueness of this C-fiber deficit by performing a quantitative anatomical analysis of several peripheral nerves in five further members of the Bathyergidae mole-rat family: silvery (Heliophobius argenteocinereus), giant (Fukomys mechowii), Damaraland (Fukomys damarensis), Mashona (Fukomys darlingi), and Natal (Cryptomys hottentotus natalensis) mole-rats. In the largely cutaneous saphenous and sural nerves, the naked mole-rat had the lowest C:A-fiber ratio (∼1.5:1 compared with ∼3:1), whereas, in nerves innervating both skin and muscle (common peroneal and tibial) or just muscle (lateral/medial gastrocnemius), this pattern was mostly absent. We asked whether lack of hair follicles alone accounts for the C-fiber paucity by using as a model a mouse that loses virtually all its hair as a consequence of conditional deletion of the β-catenin gene in the skin. These β-catenin loss-of function mice (β-cat LOF mice) displayed only a mild decrease in C:A-fiber ratio compared with wild-type mice (4.42 compared with 3.81). We suggest that the selective cutaneous C-fiber deficit in the cutaneous nerves of naked mole-rats is unlikely to be due primarily to lack of skin hair follicles. Possible mechanisms contributing to this unique peripheral nerve anatomy are discussed. Copyright © 2012 Wiley Periodicals, Inc.

Sonography-guided recording for superficial peroneal sensory nerve conduction study.

Science.gov (United States)

Kim, Ki Hoon; Park, Byung Kyu; Kim, Dong Hwee; Kim, Yuntae

2018-04-01

We sought to establish the optimal recording position for antidromic conduction of the superficial peroneal nerve (SPN) by using ultrasonography (USG). The sensory nerve action potentials (SNAPs) of the intermediate dorsal cutaneous nerve (IDCN) and medial dorsal cutaneous nerve (MDCN) in 64 limbs of 32 healthy participants were recorded (nerve conduction study [NCS]-1). Both nerves were identified by using USG, and the SNAPs were obtained from the USG-guided repositioned electrodes (NCS-2). The IDCN and MDCN were located at 29.3% ± 5.1% and 43.9% ± 4.9% of the intermalleolar distance from the lateral malleolus, respectively. Significantly greater amplitude was shown for SNAPs of both nerves in NCS-2 versus NCS-1. The optimal recording position is likely to be lateral, one-third from the lateral malleolus for the IDCN, and just lateral to the midpoint of the intermalleolar line for the MDCN. When the SPN response is unexpectedly attenuated, USG-guided repositioning of the electrodes should be considered. Muscle Nerve 57: 628-633, 2018. © 2017 Wiley Periodicals, Inc.

Phrenic nerve conduction studies: normative data and technical aspects

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Analucia Abreu Maranhão

Full Text Available ABSTRACT Objective: The aim of the present study was to define normative data of phrenic nerve conduction parameters of a healthy population. Methods: Phrenic nerve conduction studies were performed in 27 healthy volunteers. Results: The normative limits for expiratory phrenic nerve compound muscle action potential were: amplitude (0.47 mv - 0.83 mv, latency (5.74 ms - 7.10 ms, area (6.20 ms/mv - 7.20 ms/mv and duration (18.30 ms - 20.96 ms. Inspiratory normative limits were: amplitude (0.67 mv - 1.11 mv, latency (5.90 ms - 6.34 ms, area (5.62 ms/mv - 6.72 ms/mv and duration (13.77 ms - 15.37 ms. Conclusion: The best point of phrenic nerve stimulus in the neck varies among individuals between the medial and lateral border of the clavicular head of the sternocleidomastoid muscle and stimulation of both sites, then choosing the best phrenic nerve response, seems to be the appropriate procedure.

Phrenic nerve conduction studies: normative data and technical aspects.

Science.gov (United States)

Maranhão, Analucia Abreu; Carvalho, Sonia Regina da Silva; Caetano, Marcelo Ribeiro; Alamy, Alexandre Hofke; Peixoto, Eduardo Mesquita; Filgueiras, Pedro Del Esporte Peçanha

2017-12-01

The aim of the present study was to define normative data of phrenic nerve conduction parameters of a healthy population. Phrenic nerve conduction studies were performed in 27 healthy volunteers. The normative limits for expiratory phrenic nerve compound muscle action potential were: amplitude (0.47 mv - 0.83 mv), latency (5.74 ms - 7.10 ms), area (6.20 ms/mv - 7.20 ms/mv) and duration (18.30 ms - 20.96 ms). Inspiratory normative limits were: amplitude (0.67 mv - 1.11 mv), latency (5.90 ms - 6.34 ms), area (5.62 ms/mv - 6.72 ms/mv) and duration (13.77 ms - 15.37 ms). The best point of phrenic nerve stimulus in the neck varies among individuals between the medial and lateral border of the clavicular head of the sternocleidomastoid muscle and stimulation of both sites, then choosing the best phrenic nerve response, seems to be the appropriate procedure.

The longitudinal epineural incision and complete nerve transection method for modeling sciatic nerve injury

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Xing-long Cheng

2015-01-01

Full Text Available Injury severity, operative technique and nerve regeneration are important factors to consider when constructing a model of peripheral nerve injury. Here, we present a novel peripheral nerve injury model and compare it with the complete sciatic nerve transection method. In the experimental group, under a microscope, a 3-mm longitudinal incision was made in the epineurium of the sciatic nerve to reveal the nerve fibers, which were then transected. The small, longitudinal incision in the epineurium was then sutured closed, requiring no stump anastomosis. In the control group, the sciatic nerve was completely transected, and the epineurium was repaired by anastomosis. At 2 and 4 weeks after surgery, Wallerian degeneration was observed in both groups. In the experimental group, at 8 and 12 weeks after surgery, distinct medullary nerve fibers and axons were observed in the injured sciatic nerve. Regular, dense myelin sheaths were visible, as well as some scarring. By 12 weeks, the myelin sheaths were normal and intact, and a tight lamellar structure was observed. Functionally, limb movement and nerve conduction recovered in the injured region between 4 and 12 weeks. The present results demonstrate that longitudinal epineural incision with nerve transection can stably replicate a model of Sunderland grade IV peripheral nerve injury. Compared with the complete sciatic nerve transection model, our method reduced the difficulties of micromanipulation and surgery time, and resulted in good stump restoration, nerve regeneration, and functional recovery.

Scaffoldless tissue-engineered nerve conduit promotes peripheral nerve regeneration and functional recovery after tibial nerve injury in rats

Institute of Scientific and Technical Information of China (English)

Aaron M. Adams; Keith W. VanDusen; Tatiana Y. Kostrominova; Jacob P. Mertens; Lisa M. Larkin

2017-01-01

Damage to peripheral nerve tissue may cause loss of function in both the nerve and the targeted muscles it innervates. This study compared the repair capability of engineered nerve conduit (ENC), engineered fibroblast conduit (EFC), and autograft in a 10-mm tibial nerve gap. ENCs were fabricated utilizing primary fibroblasts and the nerve cells of rats on embryonic day 15 (E15). EFCs were fabricated utilizing primary fi-broblasts only. Following a 12-week recovery, nerve repair was assessed by measuring contractile properties in the medial gastrocnemius muscle, distal motor nerve conduction velocity in the lateral gastrocnemius, and histology of muscle and nerve. The autografts, ENCs and EFCs reestablished 96%, 87% and 84% of native distal motor nerve conduction velocity in the lateral gastrocnemius, 100%, 44% and 44% of native specific force of medical gastrocnemius, and 63%, 61% and 67% of native medial gastrocnemius mass, re-spectively. Histology of the repaired nerve revealed large axons in the autograft, larger but fewer axons in the ENC repair, and many smaller axons in the EFC repair. Muscle histology revealed similar muscle fiber cross-sectional areas among autograft, ENC and EFC repairs. In conclusion, both ENCs and EFCs promot-ed nerve regeneration in a 10-mm tibial nerve gap repair, suggesting that the E15 rat nerve cells may not be necessary for nerve regeneration, and EFC alone can suffice for peripheral nerve injury repair.

Chronic migraine is associated with reduced corneal nerve fiber density and symptoms of dry eye.

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Kinard, Krista I; Smith, A Gordon; Singleton, J Robinson; Lessard, Margaret K; Katz, Bradley J; Warner, Judith E A; Crum, Alison V; Mifflin, Mark D; Brennan, Kevin C; Digre, Kathleen B

2015-04-01

We used in vivo corneal confocal microscopy to investigate structural differences in the sub-basal corneal nerve plexus in chronic migraine patients and a normal population. We used a validated questionnaire and tests of lacrimal function to determine the prevalence of dry eye in the same group of chronic migraine patients. Activation of the trigeminal system is involved in migraine. Corneal nociceptive sensation is mediated by trigeminal axons that synapse in the gasserian ganglion and the brainstem, and serve nociceptive, protective, and trophic functions. Noninvasive imaging of the corneal sub-basal nerve plexus is possible with in vivo corneal confocal microscopy. For this case-control study, we recruited chronic migraine patients and compared them with a sex- and age-similar group of control subjects. Patients with peripheral neuropathy, a disease known to be associated with a peripheral neuropathy, or prior corneal or intraocular surgery were excluded. Participants underwent in vivo corneal confocal microscopy using a Heidelberg Retinal Tomography III confocal microscope with a Rostock Cornea Module. Nerve fiber length, nerve branch density, nerve fiber density, and tortuosity coefficient were measured using established methodologies. Migraine participants underwent testing of basal tear production with proparacaine, corneal sensitivity assessment with a cotton-tip applicator, measurement of tear break-up time, and completion of a validated dry eye questionnaire. A total of 19 chronic migraine patients and 30 control participants completed the study. There were no significant differences in age or sex. Nerve fiber density was significantly lower in migraine patients compared with controls (48.4 ± 23.5 vs. 71.0 ± 15.0 fibers/mm2 , P dry eye syndrome. We found that in the sample used in this study, the presence of structural changes in nociceptive corneal axons lends further support to the hypothesis that the trigeminal system plays a critical role

Renal hemodynamic effects of activation of specific renal sympathetic nerve fiber groups.

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DiBona, G F; Sawin, L L

1999-02-01

To examine the effect of activation of a unique population of renal sympathetic nerve fibers on renal blood flow (RBF) dynamics, anesthetized rats were instrumented with a renal sympathetic nerve activity (RSNA) recording electrode and an electromagnetic flow probe on the ipsilateral renal artery. Peripheral thermal receptor stimulation (external heat) was used to activate a unique population of renal sympathetic nerve fibers and to increase total RSNA. Total RSNA was reflexly increased to the same degree with somatic receptor stimulation (tail compression). Arterial pressure and heart rate were increased by both stimuli. Total RSNA was increased to the same degree by both stimuli but external heat produced a greater renal vasoconstrictor response than tail compression. Whereas both stimuli increased spectral density power of RSNA at both cardiac and respiratory frequencies, modulation of RBF variability by fluctuations of RSNA was small at these frequencies, with values for the normalized transfer gain being approximately 0.1 at >0.5 Hz. During tail compression coherent oscillations of RSNA and RBF were found at 0.3-0.4 Hz with normalized transfer gain of 0.33 +/- 0.02. During external heat coherent oscillations of RSNA and RBF were found at both 0.2 and 0.3-0.4 Hz with normalized transfer gains of 0. 63 +/- 0.05 at 0.2 Hz and 0.53 +/- 0.04 to 0.36 +/- 0.02 at 0.3-0.4 Hz. Renal denervation eliminated the oscillations in RBF at both 0.2 and 0.3-0.4 Hz. These findings indicate that despite similar increases in total RSNA, external heat results in a greater renal vasoconstrictor response than tail compression due to the activation of a unique population of renal sympathetic nerve fibers with different frequency-response characteristics of the renal vasculature.

Correlation between local glaucomatous visual field defects and loss of nerve fiber layer thickness measured with polarimetry and spectral domain OCT.

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Horn, Folkert K; Mardin, Christian Y; Laemmer, Robert; Baleanu, Delia; Juenemann, Anselm M; Kruse, Friedrich E; Tornow, Ralf P

2009-05-01

To study the correlation between local perimetric field defects and glaucoma-induced thickness reduction of the nerve layer measured in the peripapillary area with scanning laser polarimetry (SLP) and spectral domain optical coherence tomography (SOCT) and to compare the results with those of a theoretical model. The thickness of the retinal nerve fiber layer was determined in 32 sectors (11.25 degrees each) by using SLP with variable cornea compensation (GDxVCC; Laser Diagnostics, San Diego, CA) and the newly introduced high-resolution SOCT (Spectralis; Heidelberg Engineering, Heidelberg, Germany). Eighty-eight healthy subjects served as control subjects, to determine the thickness deviation in patients with glaucoma. The relationship between glaucomatous nerve fiber reduction and visual field losses was calculated in six nerve fiber bundle-related areas. Sixty-four patients at different stages of open-angle glaucoma and 26 patients with ocular hypertension underwent perimetry (Octopus G1; Haag-Streit, Köniz, Switzerland) and measurements with the two morphometric techniques. Sector-shaped analyses between local perimetric losses and reduction of the retinal nerve fiber layer thickness showed a significant association for corresponding areas except for the central visual field in SLP. Correlation coefficients were highest in the area of the nasal inferior visual field (SOCT, -0.81; SLP, -0.57). A linear model describes the association between structural and functional damage. Localized perimetric defects can be explained by reduced nerve fiber layer thickness. The data indicate that the present SOCT is useful for determining the functional-structural relationship in peripapillary areas and that association between perimetric defects and corresponding nerve fiber losses is stronger for SOCT than for the present SLP. (ClinicalTrials.gov number, NCT00494923.).

An Evaluation of Peripapillary Retinal Nerve Fiber Layer Thickness in Children With Epilepsy Receiving Treatment of Valproic Acid.

Science.gov (United States)

Dereci, Selim; Koca, Tuğba; Akçam, Mustafa; Türkyilmaz, Kemal

2015-07-01

We investigated the peripapillary retinal nerve fiber layer thickness with optical coherence tomography in epileptic children receiving valproic acid monotherapy. The study was conducted on children aged 8-16 years who were undergoing valproic acid monotherapy for epilepsy. The study group comprised a total of 40 children who met the inclusion criteria and 40 healthy age- and sex-matched children as a control group. Children with at least a 1-year history of epilepsy and taking 10-40 mg/kg/day treatment were included in the study. Peripapillary retinal nerve fiber layer thickness measurements were performed using Cirrus HD optical coherence tomography. All children and parents were informed about the study and informed consent was obtained from the parents of all the participants. The study group included 21 girls and 19 boys with a mean age of 10.6 ± 2.3 years. According to the results of optical coherence tomography measurements, the mean peripapillary retinal nerve fiber layer thickness was 91.6 ± 9.7 in the patient group and 95.5 ± 7.4 μm in the control group (P epilepsy who were receiving valproic acid monotherapy compared with healthy children. This situation can lead to undesirable results in terms of eye health. New studies are needed to investigate whether these findings are the result of epilepsy or can be attributed to valproic acid and whether there are adverse effects of valproic acid later in life. Copyright © 2015 Elsevier Inc. All rights reserved.

[Effect of meliae toosendan fructus on nerves system and its mechanism].

Science.gov (United States)

Xiang, Xiao-Xue; Tang, Da-Xuan; Xiong, Jing-Yue; Liang, Ya-Jun; Mu, Dao-Hua; Yang, Xiao-Wei; Hang, Min; Tan, Zheng-Huai

2013-05-01

To study the effect of the ethanol extract of stir-bake to yellowish Meliae Toosendan Fructus on nerve system and its mechanism. The effect of the ethanol extract on sensory nerve was carried out through ache models induced by hot board method and radiant heat stimulation method in mice. The thermalgesia liminal value was investigated. The effect of the ethanol extract on the A-delta fiber and C fiber was measured by electrical stimulation procedure. Motor nerve conduction velocity (NCV) was measured by indirect detection method in vivo. The pathology changes of the motor nerve were observed by transmission electron microscope and the silver stain test. The ethanol extract of Meliae Toosendan Fructus could increase the thermalgesia liminal value of mice and reduce the conduction velocity of motor nerves. Meanwhile, pathology results showed the changes of the fiber of motor nerve, including demyelination and the number of Schwann cells dropping. The ethanol extract of stir-bake to yellowish Meliae Toosendan Fructus can reduce the pain sensitivity of mice and slow down NCV, which may be related to decreasing of the number of Schwann cells.

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...... 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....

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

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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

Evidence for a intimate relationship between mast cells and nerve fibers in the tongue of the frog, Rana esculenta

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Chieffi Baccari, Gabriella; Minucci, Sergio [Naples, II Univ. (Italy). Dipt. di Fisiologia Umana e Funzioni Biologiche Integrate `Filippo Bottazzi`

1997-12-31

Morphological and ultrastructural association of mast cells and nerve fibers were studied in the tongue of the frog Rana esculenta. The number of mast cells in the tongue (253 {+-} 45 / mm{sup 2}) is far the highest of the frog tissue as far as people know. They are distributed throughout the connective tissue among the muscular fibers, near arterioles and venules but predominantly in close association and within the nerves. They are often embedded in the endoneurium within a nerve bundle near to myelinic or unmyelinic fibers and in membrane-to-membrane contact with axonlike processes. Just for the richness of mast cells, the tongue of the frog could represent an useful model to study the relationship between these cells and the peripheral nervous system.

Evidence for a intimate relationship between mast cells and nerve fibers in the tongue of the frog, Rana esculenta

Energy Technology Data Exchange (ETDEWEB)

Chieffi Baccari, Gabriella; Minucci, Sergio [Naples, II Univ. (Italy). Dipt. di Fisiologia Umana e Funzioni Biologiche Integrate ` Filippo Bottazzi`

1998-12-31

Morphological and ultrastructural association of mast cells and nerve fibers were studied in the tongue of the frog Rana esculenta. The number of mast cells in the tongue (253 {+-} 45 / mm{sup 2}) is far the highest of the frog tissue as far as people know. They are distributed throughout the connective tissue among the muscular fibers, near arterioles and venules but predominantly in close association and within the nerves. They are often embedded in the endoneurium within a nerve bundle near to myelinic or unmyelinic fibers and in membrane-to-membrane contact with axonlike processes. Just for the richness of mast cells, the tongue of the frog could represent an useful model to study the relationship between these cells and the peripheral nervous system.

MR neurography of the median nerve at 3.0 T: Optimization of diffusion tensor imaging and fiber tractography

International Nuclear Information System (INIS)

Guggenberger, Roman; Eppenberger, Patrick; Markovic, Daniel; Nanz, Daniel; Chhabra, Avneesh; Pruessmann, Klaas P.; Andreisek, Gustav

2012-01-01

Objectives: The purpose of this study was to systematically assess the optimal b-value and reconstruction parameters for DTI and fiber tractography of the median nerve at 3.0 T. Methods: Local ethical board approved study with 45 healthy volunteers (15 men, 30 women; mean age, 41 ± 3.4 years) who underwent DTI of the right wrist at 3.0 T. A single-shot echo-planar-imaging sequence (TR/TE 10123/40 ms) was acquired at four different b-values (800, 1000, 1200, and 1400 s/mm 2 ). Two independent readers performed post processing and fiber-tractography. Fractional anisotropy (FA) maps were calculated. Fiber tracts of the median nerve were generated using four different algorithms containing different FA thresholds and different angulation tolerances. Data were evaluated quantitatively and qualitatively. Results: Tracking algorithms using a minimum FA threshold of 0.2 and a maximum angulation of 10° were significantly better than other algorithms. Fiber tractography generated significantly longer fibers in DTI acquisitions with higher b-values (1200 and 1400 s/mm 2 versus 800 s/mm 2 ; p 2 (p 2 for DTI of the median nerve at 3.0 T. Optimal reconstruction parameters for fiber tractography should encompass a minimum FA threshold of 0.2 and a maximum angulation tolerance of 10.

Highly Conductive Graphene/Ag Hybrid Fibers for Flexible Fiber-Type Transistors.

Science.gov (United States)

Yoon, Sang Su; Lee, Kang Eun; Cha, Hwa-Jin; Seong, Dong Gi; Um, Moon-Kwang; Byun, Joon-Hyung; Oh, Youngseok; Oh, Joon Hak; Lee, Wonoh; Lee, Jea Uk

2015-11-09

Mechanically robust, flexible, and electrically conductive textiles are highly suitable for use in wearable electronic applications. In this study, highly conductive and flexible graphene/Ag hybrid fibers were prepared and used as electrodes for planar and fiber-type transistors. The graphene/Ag hybrid fibers were fabricated by the wet-spinning/drawing of giant graphene oxide and subsequent functionalization with Ag nanoparticles. The graphene/Ag hybrid fibers exhibited record-high electrical conductivity of up to 15,800 S cm(-1). As the graphene/Ag hybrid fibers can be easily cut and placed onto flexible substrates by simply gluing or stitching, ion gel-gated planar transistors were fabricated by using the hybrid fibers as source, drain, and gate electrodes. Finally, fiber-type transistors were constructed by embedding the graphene/Ag hybrid fiber electrodes onto conventional polyurethane monofilaments, which exhibited excellent flexibility (highly bendable and rollable properties), high electrical performance (μh = 15.6 cm(2) V(-1) s(-1), Ion/Ioff > 10(4)), and outstanding device performance stability (stable after 1,000 cycles of bending tests and being exposed for 30 days to ambient conditions). We believe that our simple methods for the fabrication of graphene/Ag hybrid fiber electrodes for use in fiber-type transistors can potentially be applied to the development all-organic wearable devices.

Miconazole enhances nerve regeneration and functional recovery after sciatic nerve crush injury.

Science.gov (United States)

Lin, Tao; Qiu, Shuai; Yan, Liwei; Zhu, Shuang; Zheng, Canbin; Zhu, Qingtang; Liu, Xiaolin

2018-05-01

Improving axonal outgrowth and remyelination is crucial for peripheral nerve regeneration. Miconazole appears to enhance remyelination in the central nervous system. In this study we assess the effect of miconazole on axonal regeneration using a sciatic nerve crush injury model in rats. Fifty Sprague-Dawley rats were divided into control and miconazole groups. Nerve regeneration and myelination were determined using histological and electrophysiological assessment. Evaluation of sensory and motor recovery was performed using the pinprick assay and sciatic functional index. The Cell Counting Kit-8 assay and Western blotting were used to assess the proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole promoted axonal regrowth, increased myelinated nerve fibers, improved sensory recovery and walking behavior, enhanced stimulated amplitude and nerve conduction velocity, and elevated proliferation and neurotrophic expression of RSC 96 Schwann cells. Miconazole was beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Muscle Nerve 57: 821-828, 2018. © 2017 Wiley Periodicals, Inc.

Effects of cholinergic compounds on the axon-Schwann cell relationship in the squid nerve fiber.

Science.gov (United States)

Villegas, J

1975-04-01

The effects of acetylcholine, carbamylcholine, D-tubocurarine, eserine, and alpha-bungarotoxin on the Schwann cell electrical potential of resting and stimulated squid nerve fibers were studied. Acetylcholine (10-7 M) and barbamylcholine (10-6 M) induce a prolonged hyper polarization in the Schwann cells of the unstimulated nerve fiber. In the presence of carbamylcholine (10-6 M) the behavior of the Schwann cell membrane to changes in the external potassium concentration approximates the behavior of an ideal potassium electrode. D-Tubocurarine (10-9 M) blocks the hyperpolarizing effects of nerve impulse trains and carbamylcholine (10-6 M), whereas at the same concentration eserine prolongs the Schwann cell hyperpolarizations induced by axon stimulation or by acetylcholine (10-7 M). alpha-Bungarotoxin (10-9M) also blocks the hyperpolarizing effect of nerve impulse trains and of carbamylcholine. D-Tubocurarine (10-5M) protects the Schwann cells against the irreversible action of alpha-bungarotoxin. These results show the existence of acetylcholine receptors in the Schwann cell membrane. Preliminary measurements of the binding of 125I-alpha bungarotoxin to the plasma membranes isolated from squid nerves also indicate the presence of acetylcholine receptors. These findings support the involvement of cholinergic mechanisms in the axon-Schwann cell relationship previously described.

Retinal nerve fiber and optic disc morphology using spectral-domain optical coherence tomography in scleroderma patients.

Science.gov (United States)

Sahin-Atik, Sevinc; Koc, Feray; Akin-Sari, Sirin; Ozmen, Mustafa

2017-05-11

To evaluate the optic nerve head parameters and peripapillary retinal nerve fiber layer using spectral-domain optical coherence tomography (SD-OCT) in a systemic sclerosis (SSc) cohort and age-matched controls to determine whether SSc patients have an increased risk of normal-tension glaucoma (NTG). We examined 30 patients (3 male, 27 female) with SSc and 28 age- and sex-matched controls. Retinal nerve fiber and optic disc morphology were evaluated using Cirrus SD-OCT. Optic disc morphology measurements including disc area, rim area, average and vertical cup/disc (C/D) ratio, and cup volume were not significantly different between the study groups. The average and 4-quadrant retinal nerve fiber layer (RNFL) measurements of the C/D >0.3 subgroups were not significantly different in the patients and controls. These values were also similar for the C/D >0.5 subgroups except that the average inferior quadrant RNFL thickness of the right eyes in the patient subgroup was significantly thinner than in the control subgroup (p<0.05). Our SSc cohort had relatively shorter disease duration but increased prevalence of early glaucomatous damage signs. Our findings indicate that SSc is a risk factor for developing normal-tension glaucoma. Further studies combined with visual field evaluation are necessary to identify the long-term glaucomatous effects of SSc.

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

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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.

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...

Optical coherence tomography in retinitis pigmentosa: reproducibility and capacity to detect macular and retinal nerve fiber layer thickness alterations.

Science.gov (United States)

Garcia-Martin, Elena; Pinilla, Isabel; Sancho, Eva; Almarcegui, Carmen; Dolz, Isabel; Rodriguez-Mena, Diego; Fuertes, Isabel; Cuenca, Nicolas

2012-09-01

To evaluate the ability of time-domain and Fourier-domain optical coherence tomographies (OCTs) to detect macular and retinal nerve fiber layer atrophies in retinitis pigmentosa (RP). To test the intrasession reproducibility using three OCT instruments (Stratus, Cirrus, and Spectralis). Eighty eyes of 80 subjects (40 RP patients and 40 healthy subjects) underwent a visual field examination, together with 3 macular scans and 3 optic disk evaluations by the same experienced examiner using 3 OCT instruments. Differences between healthy and RP eyes were compared. The relationship between measurements with each OCT instrument was evaluated. Repeatability was studied by intraclass correlation coefficients and coefficients of variation. Macular and retinal nerve fiber layer atrophies were detected in RP patients for all OCT parameters. Macular and retinal nerve fiber layer thicknesses, as determined by the different OCTs, were correlated but significantly different (P < 0.05). Reproducibility was moderately high using Stratus, good using Cirrus and Spectralis, and excellent using the Tru-track technology of Spectralis. In RP eyes, measurements showed higher variability compared with healthy eyes. Differences in thickness measurements existed between OCT instruments, despite there being a high degree of correlation. Fourier-domain OCT can be considered a valid and repeatability technique to detect retinal nerve fiber layer atrophy in RP patients.

Sciatic Nerve Conductivity is Impaired by Hamstring Strain Injuries.

Science.gov (United States)

Kouzaki, Karina; Nakazato, Koichi; Mizuno, Masuhiko; Yonechi, Tooru; Higo, Yusuke; Kubo, Yoshiaki; Kono, Tokuyoshi; Hiranuma, Kenji

2017-10-01

The aim of this study was to assess sciatic nerve conductivity in athletes with a history of hamstring strain injuries. Twenty-seven athletes with a history of hamstring strain injuries were included in the injured group. The control group consisted of 16 uninjured participants. We measured the proximal and distal latencies and calculated the sciatic nerve conduction velocity to evaluate neuronal conductivity. The results were expressed as median values and interquartile ranges. Both proximal latency and distal latency of the injured limb in the injured group were significantly longer than those of the uninjured limb (phamstring strain injuries. © Georg Thieme Verlag KG Stuttgart · New York.

Fabrication and Protein Conjugation of Aligned Polypyrrole-Poly(L-lactic acid) Fibers Film with the Conductivity and Stability.

Science.gov (United States)

Qin, Jiabang; Huang, Zhongbing; Yin, Guangfu; Yang, Anneng; Han, Wei

2016-03-01

The conducting composite scaffold, including fiber-cores of aligned poly(L-lactic acid) (PLLA) and shell-layer of polypyrrole (PPy), was fabricated, and then bovine serum albumin (BSA) was conjugated on the PPy shell-layer. Aligned PLLA fibers (about 300 nm diameter) were obtained by electrospinning and rotating drum collection, and then coated by PPy nanoparticles (NPs, about 50 nm diameter) via chemical oxidation. The surface resistivity of PPy-PLLA fibers film were 0.971, 0.874 kΩ. cm at the fiber's vertical and parallel directions, respectively. The results of PPy-PLLA fibers film immersed in phosphate buffer saline for 8 d indicated that the fibers morphology and the film conductivity were not significantly changed, and the fluorescent images showed that FITC-labeled BSA (FITC-BSA) were successfully conjugated in the fibers film with carbodiimide chemistry, and the largest amount of FITC-BSA conjugated in the fibers film from 100 μg/mL proteins solution was 31.31 μg/cm2 due to lots of poly(glutamic acid) in surface-nanogrooves of the fibers surface. Under electrical stimulation of 100 mV, the fibers film was accompanied the release of all conjugated FITC-BSA with the detachment of some PPy NPs. These results suggested that PPy-PLLA fibers film would be potentially applied in the construction of degradable tissue engineering scaffold with protein factors, especially neurotrophic factors for nerve tissue repair.

Retinal nerve fiber layer thickness map determined from optical coherence tomography images

NARCIS (Netherlands)

Mujat, M.; Chan, R. C.; Cense, B.; Park, B.H.; Joo, C.; Akkin, T.; Chen, TC; de Boer, JF

2005-01-01

We introduce a method to determine the retinal nerve fiber layer (RNFL) thickness in OCT images based on anisotropic noise suppression and deformable splines. Spectral-Domain Optical Coherence Tomography (SDOCT) data was acquired at 29 kHz A-line rate with a depth resolution of 2.6 mum and a depth

Comparison of four different nerve conduction techniques of the superficial fibular sensory nerve.

Science.gov (United States)

Saffarian, Mathew R; Condie, Nathan C; Austin, Erica A; Mccausland, Katie E; Andary, Michael T; Sylvain, James R; Mull, Iian R; Zemper, Eric D; Jannausch, Mary L

2017-09-01

There are many different nerve conduction study (NCS) techniques to study the superficial fibular sensory nerve (SFSN). We present reference distal latency values and comparative data regarding 4 different NCS for the SFSN. Four different NCS techniques, Spartan technique, Izzo techniques (medial and intermediate dorsal cutaneous branches), and Daube technique, were performed on (114) healthy volunteers. A total of 108 subjects with 164 legs were included. The mean latency of the Spartan technique was longest (3.9 ± 0.3 ms) while the Daube technique was the shortest (3.6 ± 0.7 ms). The mean amplitude of the Daube technique displayed the highest (15.2 ± 8.2 μV) with the Spartan technique having the lowest (8.7 ± 4.2 μV). Among the absent sensory nerve action potentials (SNAPs), the Spartan technique was absent only twice (1.2%) and the Izzo Medial technique was absent more than the other techniques (2.9%). All 4 techniques were reliable methods for obtaining the superficial fibular nerve SNAP, present in 95% of individuals. Muscle Nerve 56: 458-462, 2017. © 2017 Wiley Periodicals, Inc.

THERMAL CONDUCTIVITY OF SIC AND C FIBERS

Energy Technology Data Exchange (ETDEWEB)

Youngblood, Gerald E.; Senor, David J.; Kowbel, W.; Webb, J.; Kohyama, Akira

2000-09-01

Several rod-shaped specimens with uniaxially packed fibers (Hi-Nicalon, Hi-Nicalon Type S, Tyranno SA and Amoco K1100 types) and a pre-ceramic polymer matrix have been fabricated. By using appropriate analytic models, the bare fiber thermal conductivity (Kf) and the interface thermal conductance (h) will be determined as a function of temperature up to 1000?C before and after irradiation for samples cut from these rods. Initial results are: (1) for unirradiated Hi-Nicalon SiC fiber, Kf varied from 4.3 up to 5.9 W/mK for the 27-1000?C range, (2) for unirradiated K1100 graphite fiber, Kf varied from 576 down to 242 W/mK for the 27-1000?C range, and (3) h = 43 W/cm2K at 27?C as a typical fiber/matrix interface conductance.

Variations in retinal nerve fiber layer measurements on optical coherence tomography after implantation of trifocal intraocular lens.

Science.gov (United States)

García-Bella, Javier; Martínez de la Casa, José M; Talavero González, Paula; Fernández-Vigo, José I; Valcarce Rial, Laura; García-Feijóo, Julián

2018-01-01

To establish the changes produced after implantation of a trifocal intraocular lens (IOL) on retinal nerve fiber layer measurements performed with Fourier-domain optical coherence tomography (OCT). This prospective study included 100 eyes of 50 patients with bilateral cataract in surgical range, no other associated ocular involvement, refractive errors between +5 and -5 spherical diopters, and less than 1.5 D of corneal astigmatism. The eyes were operated by phacoemulsification with implantation of 2 different trifocal IOLs (FineVision and AT LISA tri 839MP) in randomized equal groups. Cirrus OCT and Spectralis OCT were performed before surgery and 3 months later. Both analyzed the thickness of the nerve fiber layer and thickness divided by quadrants (6 in case of Spectralis and 4 in case of Cirrus HD). The mean age of patients was 67.5 ± 5.8 years. The global nerve fiber layer thickness measured with Spectralis OCT was 96.77 μm before surgery and 99.55 μm after. With Cirrus OCT, the global thickness was 85.29 μm before surgery and 89.77 μm after. Statistically significant differences in global thickness measurements between preimplantation and postimplantation of the IOL were found with both OCT in the 2 groups. Statistically significant differences were also found in temporal and superior quadrants. The implantation of a diffractive trifocal IOL alters the results of the optic nerve fiber layer on Fourier-domain OCT in these patients, which should be taken into account in the posterior study of these patients.

Split bundle detection in polarimetric images of the human retinal nerve fiber layer

NARCIS (Netherlands)

Vermeer, K. A.; Reus, N. J.; Vos, F. M.; Lemij, H. G.; Vossepoel, A. M.

2007-01-01

One method for assessing pathological retinal nerve fiber layer (NFL) appearance is by comparing the NFL to normative values, derived from healthy subjects. These normative values will be more specific when normal physiological differences are taken into account. One common variation is a split

Biosynthesis of fatty acids and cholesterol in squid giant nerve fiber

International Nuclear Information System (INIS)

Tanaka, T.; Kishimoto, Y.; Gould, R.M.

1987-01-01

The giant nerve fiber of squid 3 (loligo pealel) was incubated with [1- 14 C]acetate and ( 3 H)myristate. Fifty-five percent of the radioactivity incorporated from acetate was recovered in fatty acid methyl esters (FAME). The FAME was fractionated by AgNO 3 -impregnated TLC plate; and 52%, 31%, 0.3%, 5%, and 11% of the radioactivity was recovered in spots associated with saturated, monoenes, dienes, trienes, and polyenes, respectively. The saturated FAME was further fractionated by reverse-phase HPLC; and 4, 47, 1, and 48% of the radioactivity was recovered in 14:0, 16:0, 17:0, and 18:0, respectively. Most radioactivity from polyenes migrated to the spot containing saturated FAME, after catalytical hydrogenation. Cholesterol was isolated and converted to dibromoderivative and the derivative was recrystallized. No radioactivity was found in purified dibromocholesterol. Nearly all radioactivity from myristate-labeled tissue was recovered in saturated FAME. Reverse-phase HPLC showed that 71%, 25%, and 3% of radioactivity was associated with 14:0, 16:0, and 18:0, respectively. These results indicate that the squid giant nerve fibers can synthesize fatty acids by de novo and also by chain elongation and desaturation, though at a slower rate

Nerve fiber layer (NFL) degeneration associated with acute q-switched laser exposure in the nonhuman primate

Science.gov (United States)

Zwick, Harry; Zuclich, Joseph A.; Stuck, Bruce E.; Gagliano, Donald A.; Lund, David J.; Glickman, Randolph D.

1995-01-01

We have evaluated acute laser retinal exposure in non-human primates using a Rodenstock scanning laser ophthalmoscope (SLO) equipped with spectral imaging laser sources at 488, 514, 633, and 780 nm. Confocal spectral imaging at each laser wavelength allowed evaluation of the image plane from deep within the retinal vascular layer to the more superficial nerve fiber layer in the presence and absence of the short wavelength absorption of the macular pigment. SLO angiography included both fluorescein and indocyanine green procedures to assess the extent of damage to the sensory retina, the retinal pigment epithelium (RPE), and the choroidal vasculature. All laser exposures in this experiment were from a Q-switched Neodymium laser source at an exposure level sufficient to produce vitreous hemorrhage. Confocal imaging of the nerve fiber layer revealed discrete optic nerve sector defects between the lesion site and the macula (retrograde degeneration) as well as between the lesion site and the optic disk (Wallerian degeneration). In multiple hemorrhagic exposures, lesions placed progressively distant from the macula or overlapping the macula formed bridging scars visible at deep retinal levels. Angiography revealed blood flow disturbance at the retina as well as at the choroidal vascular level. These data suggest that acute parafoveal laser retinal injury can involve both direct full thickness damage to the sensory and non-sensory retina and remote nerve fiber degeneration. Such injury has serious functional implications for both central and peripheral visual function.

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

Spontaneous temporal changes and variability of peripheral nerve conduction analyzed using a random effects model

DEFF Research Database (Denmark)

Krøigård, Thomas; Gaist, David; Otto, Marit

2014-01-01

SUMMARY: The reproducibility of variables commonly included in studies of peripheral nerve conduction in healthy individuals has not previously been analyzed using a random effects regression model. We examined the temporal changes and variability of standard nerve conduction measures in the leg...... reexamined after 2 and 26 weeks. There was no change in the variables except for a minor decrease in sural nerve sensory action potential amplitude and a minor increase in tibial nerve minimal F-wave latency. Reproducibility was best for peroneal nerve distal motor latency and motor conduction velocity......, sural nerve sensory conduction velocity, and tibial nerve minimal F-wave latency. Between-subject variability was greater than within-subject variability. Sample sizes ranging from 21 to 128 would be required to show changes twice the magnitude of the spontaneous changes observed in this study. Nerve...

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

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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.

DC-Evoked Modulation of Excitability of Myelinated Nerve Fibers and Their Terminal Branches; Differences in Sustained Effects of DC.

Science.gov (United States)

Kaczmarek, Dominik; Jankowska, Elzbieta

2018-03-15

Direct current (DC) evokes long-lasting changes in neuronal networks both presynaptically and postsynaptically and different mechanisms were proposed to be involved in them. Different mechanisms were also suggested to account for the different dynamics of presynaptic DC actions on myelinated nerve fibers stimulated before they entered the spinal gray matter and on their terminal branches. The aim of the present study was to examine whether these different dynamics might be related to differences in the involvement of K + channels. To this end, we compared effects of the K + channel blocker 4-amino-pyridine (4-AP) on DC-evoked changes in the excitability of afferent fibers stimulated within the dorsal columns (epidurally) and within their projection areas in the dorsal horn and motor nuclei (intraspinally). 4-AP was applied systemically in deeply anesthetized rats. DC-evoked increases in the excitability of epidurally stimulated afferent nerve fibers, and increases in field potentials evoked by these fibers, were not affected by 4-AP. In contrast, sustained decreases rather than increases in the excitability of intraspinally stimulated terminal nerve branches were evoked by local application of DC in conjunction with 4-AP. The study leads to the conclusion that 4-AP-sensitive K + channels contribute to the sustained DC-evoked post-polarization increases in the excitability at the level of terminal branches of nerve fibers but not of the nodes of Ranvier nor within the juxta-paranodal regions where other mechanisms would be involved in inducing the sustained DC-evoked changes. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Time course and predictors of median nerve conduction after carpal tunnel release.

Science.gov (United States)

Rotman, Mitchell B; Enkvetchakul, Bobby V; Megerian, J Thomas; Gozani, Shai N

2004-05-01

To identify predictors of outcome and of electrophysiologic recovery in patients with carpal tunnel syndrome (CTS) treated by endoscopic carpal tunnel release using a nerve conduction testing system (NC-Stat; NEUROMetrix, Inc, Waltham, MA). Validity of the automated nerve conduction testing system was shown by comparing presurgical distal motor latencies (DMLs) against a reference obtained by referral to an electromyography laboratory. The DML was evaluated in 48 patients with CTS. Measurements were obtained within 1 hour of surgery and at 2 weeks, 6 weeks, 3 months, and 6 months after carpal tunnel release. Presurgical and postsurgical DMLs were then compared and correlated with variables and possible predictors of outcome including age, body mass index, gender, and presurgical DMLs. The automated nerve conduction testing system DMLs matched those of reference electromyography/nerve conduction study values with high correlation. Sensitivity of the automated nerve conduction testing system when compared with a standardized CTS case definition was 89%, with a specificity of 95%. A significant correlation was found between the DML before release and the DML 1 hour after release. Moreover, maximal postsurgical DML improvement was highly dependent on the presurgical DML, with no improvement shown for the 6-ms group. Among the clinical variables of age, gender, and body mass index only age was mildly predictive of postrelease DML changes at 6 months. No other correlations between clinical variables and postsurgical DMLs were significant. In addition the predictive value of age was lost when combined with the presurgical DML in a multivariate analysis. Postsurgical changes in the median nerve DML were highly dependent on the prerelease latency. The sensitivity and specificity of a nerve conduction monitoring system in detecting and aiding in the diagnosis of CTS is useful in the long-term management of patients with CTS and can aid in determining the level of improvement

Compound sensory action potential in normal and pathological human nerves

DEFF Research Database (Denmark)

Krarup, Christian

2004-01-01

The compound sensory nerve action potential (SNAP) is the result of phase summation and cancellation of single fiber potentials (SFAPs) with amplitudes that depend on fiber diameter, and the amplitude and shape of the SNAP is determined by the distribution of fiber diameters. Conduction velocitie...... effort and attention to theory and practical detail that may be time consuming....

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.

Biomarkers of neuropathic pain in skin nerve degeneration neuropathy: contact heat-evoked potentials as a physiological signature.

Science.gov (United States)

Wu, Shao-Wei; Wang, Yi-Chia; Hsieh, Paul-Chen; Tseng, Ming-Tsung; Chiang, Ming-Chang; Chu, Chih-Pang; Feng, Fang-Ping; Lin, Yea-Huey; Hsieh, Sung-Tsang; Chao, Chi-Chao

2017-03-01

Contact heat-evoked potentials (CHEPs) have become an established method of assessing small-fiber sensory nerves; however, their potential as a physiological signature of neuropathic pain symptoms has not been fully explored. To investigate the diagnostic efficacy in examining small-fiber sensory nerve degeneration, the relationship with skin innervations, and clinical correlates with sensory symptoms, we recruited 188 patients (115 men) with length-dependent sensory symptoms and reduced intraepidermal nerve fiber (IENF) density at the distal leg to perform CHEP, quantitative sensory testing, and nerve conduction study. Fifty-seven age- and sex-matched controls were enrolled for comparison of CHEP and skin innervation. Among patients with neuropathy, 144 patients had neuropathic pain and 64 cases had evoked pain. Compared with quantitative sensory testing and nerve conduction study parameters, CHEP amplitudes showed the highest sensitivity for diagnosing small-fiber sensory nerve degeneration and exhibited the strongest correlation with IENF density in multiple linear regression. Contact heat-evoked potential amplitudes were strongly correlated with the degree of skin innervation in both patients with neuropathy and controls, and the slope of the regression line between CHEP amplitude and IENF density was higher in patients with neuropathy than in controls. Patients with evoked pain had higher CHEP amplitude than those without evoked pain, independent of IENF density. Receiver operating characteristic analysis showed that CHEP had better performance in diagnosing small-fiber sensory nerve degeneration than thermal thresholds. Furthermore, CHEPs showed superior classification accuracy with respect to evoked pain. In conclusion, CHEP is a sensitive tool to evaluate pathophysiology of small-fiber sensory nerve and serves as a physiological signature of neuropathic pain symptoms.

Expression of growth-associated protein 43 in the skin nerve fibers of patients with type 2 diabetes mellitus.

Science.gov (United States)

Bursova, Sarka; Dubovy, Petr; Vlckova-Moravcova, Eva; Nemec, Martin; Klusakova, Ilona; Belobradkova, Jana; Bednarik, Josef

2012-04-15

The growth-associated protein 43 (GAP-43) is known as a marker of regenerating nerve fibers and their continuous remodeling in the adult human skin. The purpose of this pilot study was to investigate a possible role for GAP-43 in the detection of the early stages of small-fiber neuropathy in patients with type 2 diabetes mellitus (DM2) as compared with a well- established and validated parameter - intra-epidermal nerve fiber density (IENFD) of protein gene product 9.5 (PGP 9.5) immunoreactive intra-epidermal C fibers. In a group of 21 patients with DM2 within three years of diagnosis (13 men, 8 women; mean age 53.9±12.8; range 30-74) and a group of 17 healthy volunteers (8 men, 9 women; mean age 55.8±8.5; range 45-70 years), skin punch biopsies were taken from a distal calf and double immunostained with both PGP 9.5 and GAP-43. In healthy controls, 96.8% of 629 PGP 9.5 immunoreactive fibers were immunostained with GAP-43; the proportion of PGP 9.5 intra-epidermal nerve fibers immunoreactive for GAP-43 in control subjects ranged from 86.5 to 100%. In DM2 patients, IENFD was significantly lower compared to controls (median, 1.5 vs. 11.2/mm; pDM2 patients compared to healthy controls (73.6% of 337 PGP 9.5 positive fibers; p<0.001); ranged from 0 to 98.1%. In conclusion, these results show that impaired regeneration of intra-epidermal C fibers in the early stages of type 2 diabetes mellitus, as indicated by GAP-43, might be a marker of incipient diabetic neuropathy. Copyright © 2011 Elsevier B.V. All rights reserved.

Relationship Between Optic Nerve Appearance and Retinal Nerve Fiber Layer Thickness as Explored with Spectral Domain Optical Coherence Tomography

Science.gov (United States)

Aleman, Tomas S.; Huang, Jiayan; Garrity, Sean T.; Carter, Stuart B.; Aleman, Wendy D.; Ying, Gui-shuang; Tamhankar, Madhura A.

2014-01-01

Purpose To study the relationship between the appearance of the optic nerve and the retinal nerve fiber layer (RNFL) thickness determined by spectral domain optical coherence tomography (OCT). Methods Records from patients with spectral domain-OCT imaging in a neuro-ophthalmology practice were reviewed. Eyes with glaucoma/glaucoma suspicion, macular/optic nerve edema, pseudophakia, and with refractive errors > 6D were excluded. Optic nerve appearance by slit lamp biomicroscopy was related to the RNFL thickness by spectral domain-OCT and to visual field results. Results Ninety-one patients (176 eyes; mean age: 49 ± 15 years) were included. Eighty-three eyes (47%) showed optic nerve pallor; 89 eyes (50.6%) showed RNFL thinning (sectoral or average peripapillary). Average peripapillary RNFL thickness in eyes with pallor (mean ± SD = 76 ± 17 μm) was thinner compared to eyes without pallor (91 ± 14 μm, P < 0.001). Optic nerve pallor predicted RNFL thinning with a sensitivity of 69% and a specificity of 75%. Optic nerve appearance predicted RNFL thinning (with a sensitivity and specificity of 81%) when RNFL had thinned by ∼ 40%. Most patients with pallor had RNFL thinning with (66%) or without (25%) visual field loss; the remainder had normal RNFL and fields (5%) or with visual field abnormalities (4%). Conclusions Optic nerve pallor as a predictor of RNFL thinning showed fair sensitivity and specificity, although it is optimally sensitive/specific only when substantial RNFL loss has occurred. Translational Relevance Finding an acceptable relationship between the optic nerve appearance by ophthalmoscopy and spectral domain-OCT RNFL measures will help the clinician's interpretation of the information provided by this technology, which is gaining momentum in neuro-ophthalmic research. PMID:25374773

Myelination and nodal formation of regenerated peripheral nerve fibers following transplantation of acutely prepared olfactory ensheathing cells

Science.gov (United States)

Dombrowski, Mary A.; Sasaki, Masanori; Lankford, Karen L.; Kocsis, Jeffery D.; Radtke, Christine

2009-01-01

Transplantation of olfactory ensheathing cells (OECs) into injured spinal cord results in improved functional outcome. Mechanisms suggested to account for this functional improvement include axonal regeneration, remyelination and neuroprotection. OECs transplanted into transected peripheral nerve have been shown to modify peripheral axonal regeneration and functional outcome. However, little is known of the detailed integration of OECs at the transplantation site in peripheral nerve. To address this issue cells populations enriched in OECs were isolated from the olfactory bulbs of adult green fluorescent protein (GFP)-expressing transgenic rats and transplanted into a sciatic nerve crush lesion which transects all axons. Five weeks to six months after transplantation the nerves were studied histologically. GFP-expressing OECs survived in the lesion and distributed longitudinally across the lesion zone. The internodal regions of individual teased fibers distal to the transection site were characterized by GFP expression in the cytoplasmic and nuclear compartments of cells surrounding the axons. Immuno-electron microscopy for GFP indicated that the transplanted OECs formed peripheral type myelin. Immunostaining for sodium channel and Caspr revealed a high density of Nav1.6 at the newly formed nodes of Ranvier which were flanked by paranodal Caspr staining. These results indicate that transplanted OECs extensively integrate into transected peripheral nerve and form myelin on regenerated peripheral nerve fibers, and that nodes of Ranvier of these axons display proper sodium channel organization. PMID:17112480

COMPARISON OF NERVE CONDUCTION VELOCITY IN TEENAGERS WITH DIFFERENT IQ

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S KHOSRAVI

2002-06-01

Full Text Available Introduction. Correlation between nerve conduction velocity (NCV in peripheral and central nervous systems and intelligence has been investigated during recent years with different results. To determine whether there is any correlation between peripheral NCV and IQ, we tested median and ulnar NCV in three groups of teenagers with different IQs. Methods. 144 normal subjects aged between 12-17 years were studied in three groups. Group I, with IQ more than 120 (measured with the Wechsler intelligence test, group II, with IQ between 90-110 and group III, with IQ below 70. All three groups matched for age and sex. For each case median and ulnar NCVs were measured in sensory and motor fibers. Mean IQ in study groups were compared using ANOVA. Results. Although the range and mean values of NCV in all tested nerves are in normal ranges but there are statistically significant differences between mean NCVs between study groups. In group I (high IQ mean NCV was higher than groups II and III and mean NCV in group III was less than groups I and II (p<0.05. IQ and NCV were not significantly different in girls and boys (p>0.05. Discussion .It is well established that IQ is a multi-factorial parameter and genetic, environment, hormones and individual physical factors such as size and volume of brain could influence intelligence. This study showed statistically difference between IQ and peripheral NCV in adolescents aged 12-17 years. Investigation of correlation between IQ, NCV and other evoked potentials in different age groups is suggested.

Localization of substance P, calcitonin gene related peptide and galanin in the nerve fibers of porcine cystic ovaries

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Mariusz Majewski

2012-01-01

Full Text Available In a previous study, we showed that both the noradrenergic and cholinergic component of ovarian innervation is markedly changed in porcine cystic ovaries. The present study is aimed at elucidating the distribution pattern of substance P- (SP, calcitonin gene related peptide CGRP- and/or galanin (GAL-containing nerve fibers within porcine cystic ovaries. The status polycysticus was induced by dexamethasone phosphate disodium salt i.m. injections performed from the 7^th until the 21^st day of the first studied estrous cycle. During the same period of time, gilts of the control group received saline. All animals were slaughtered on the expected 11^th day of the second studied estrous cycle, and their ovaries were collected. When compared to control gonad, a distinct difference in the distribution pattern and the density of SP-, CGRP- and/or GAL-immunoreactive (GAL-IR nerve fibers was observed. Thus, unlike in the control gonad, SP- and/or CGRP-IR perivascular nerve fibers were found to supply medullar blood vessels of polycystic ovary. Furthermore, the number of GAL-IR nerve fibers contributing to the ground plexus in polycystic ovaries was higher than that observed in the control gonads. Thus, as may be judged from the profound changes in the distribution pattern of differently chemically coded afferent terminals within polycystic gonads, it appears possible that neuropeptides released from these terminals may take part in the etiopathogenesis of this disorder. (Folia Histochemica et Cytobiologica 2011; Vol. 49, No. 4, pp. 622–630

Chemoattractive capacity of different lengths of nerve fragments bridging regeneration chambers for the repair of sciatic nerve defects

Institute of Scientific and Technical Information of China (English)

Jiren Zhang; Yubo Wang; Jincheng Zhang

2012-01-01

A preliminary study by our research group showed that 6-mm-long regeneration chamber bridging is equivalent to autologous nerve transplantation for the repair of 12-mm nerve defects.In this study,we compared the efficacy of different lengths (6,8,10 mm) of nerve fragments bridging 6-mm regeneration chambers for the repair of 12-mm-long nerve defects.At 16 weeks after the regeneration chamber was implanted,the number,diameter and myelin sheath thickness of the regenerated nerve fibers,as well as the conduction velocity of the sciatic nerve and gastrocnemius muscle wet weight ratio,were similar to that observed with autologous nerve transplantation.Our results demonstrate that 6-,8-and 10-mm-long nerve fragments bridging 6-mm regeneration chambers effectively repair 12-mm-long nerve defects.Because the chemoattractive capacity is not affected by the length of the nerve fragment,we suggest adopting 6-mm-long nerve fragments for the repair of peripheral nerve defects.

Peripheral nervous system maturation in preterm infants: longitudinal motor and sensory nerve conduction studies.

Science.gov (United States)

Lori, S; Bertini, Giovanna; Bastianelli, M; Gabbanini, S; Gualandi, D; Molesti, E; Dani, C

2018-04-10

To study the evolution of sensory-motor nerves in the upper and lower limbs in neurologically healthy preterm infants and to use sensory-motor studies to compare the rate of maturation in preterm infants at term age and full-term healthy neonates. The study comprised 26 neurologically normal preterm infants born at 23-33 weeks of gestational age, who underwent sensory nerve conduction and motor nerve conduction studies from plantar medial and median nerves and from tibial and ulnar nerves, respectively. We repeated the same neurophysiological studies in 19 of the preterm infants every 2 weeks until postnatal term age. The data from the preterm infants at term was matched with a group of ten full-term babies a few days after birth. The motor nerve conduction velocity of the tibial and ulnar nerves showed progressive increases in values in relation to gestational age, but there was a decrease of values in distal latencies and F wave latencies. Similarly, there was a gradual increase of sensory nerve conduction velocity values of the medial plantar and median nerves and decreases in latencies in relation to gestational age. At term age, the preterm infants showed significantly lower values of conduction velocities and distal latencies than the full-term neonates. These results were probably because the preterm infants had significantly lower weights, total length and, in particular, distal segments of the limbs at term age. The sensory-motor conduction parameters were clearly related to gestational age, but extrauterine life did not affect the maturation of the peripheral nervous system in the very preterm babies who were neurologically healthy.

Phrenic Nerve Conduction Abnormalities Correlate with Diaphragmatic Descent in Chronic Obstructive Pulmonary Disease.

Science.gov (United States)

El-Tantawi, Gihan A Younis; Imam, Mohamed H; Morsi, Tamer S

2015-01-01

Diaphragmatic weakness in chronic obstructive pulmonary disease (COPD) is ascribed to hyperinflation-induced diaphragm shortening as well as impairment in cellular and subcellular structures. Although phrenic neuropathy is known to cause diaphragmatic weakness, phrenic neuropathy is rarely considered in COPD. This work aimed at assessing phrenic nerve conduction in COPD and its relation to radiographic hyperinflation and pulmonary function. Forty COPD patients were evaluated. Radiographic parameters of lung hyperinflation were measured on postero-anterior and lateral chest x-ray films. Flow volume loop parameters were obtained from all patients. Motor conduction study of the phrenic nerves was performed and potentials were recorded over the xiphoid process and the ipsilateral 7th intercostal space. Twenty-seven healthy subjects were enrolled as controls. Parameters of phrenic nerve conduction differed significantly in patients compared to controls. Phrenic nerve abnormalities were detected in 17 patients (42.5%). Electrophysiological measures correlated with diaphragmatic angle of depression on lateral view films and with lung height on postero-anterior films. They did not correlate with the flow volume loop data or disease severity score. Phrenic nerve conduction abnormality is an appreciated finding in COPD. Nerve stretching associated with diaphragmatic descent can be a suggested mechanism for nerve lesion. The presence of phrenic neuropathy may be an additional contributing factor to diaphragmatic dysfunction in COPD patients.

Carbon nanotube and graphene nanoribbon-coated conductive Kevlar fibers.

Science.gov (United States)

Xiang, Changsheng; Lu, Wei; Zhu, Yu; Sun, Zhengzong; Yan, Zheng; Hwang, Chi-Chau; Tour, James M

2012-01-01

Conductive carbon material-coated Kevlar fibers were fabricated through layer-by-layer spray coating. Polyurethane was used as the interlayer between the Kevlar fiber and carbon materials to bind the carbon materials to the Kevlar fiber. Strongly adhering single-walled carbon nanotube coatings yielded a durable conductivity of 65 S/cm without significant mechanical degradation. In addition, the properties remained stable after bending or water washing cycles. The coated fibers were analyzed using scanning electron microcopy and a knot test. The as-produced fiber had a knot efficiency of 23%, which is more than four times higher than that of carbon fibers. The spray-coating of graphene nanoribbons onto Kevlar fibers was also investigated. These flexible coated-Kevlar fibers have the potential to be used for conductive wires in wearable electronics and battery-heated armors. © 2011 American Chemical Society

Highly thermal conductive carbon fiber/boron carbide composite material

International Nuclear Information System (INIS)

Chiba, Akio; Suzuki, Yasutaka; Goto, Sumitaka; Saito, Yukio; Jinbo, Ryutaro; Ogiwara, Norio; Saido, Masahiro.

1996-01-01

In a composite member for use in walls of a thermonuclear reactor, if carbon fibers and boron carbide are mixed, since they are brought into contact with each other directly, boron is reacted with the carbon fibers to form boron carbide to lower thermal conductivity of the carbon fibers. Then, in the present invention, graphite or amorphous carbon is filled between the carbon fibers to provide a fiber bundle of not less than 500 carbon fibers. Further, the surface of the fiber bundle is coated with graphite or amorphous carbon to suppress diffusion or solid solubilization of boron to carbon fibers or reaction of them. Then, lowering of thermal conductivity of the carbon fibers is prevented, as well as the mixing amount of the carbon fiber bundles with boron carbide, a sintering temperature and orientation of carbon fiber bundles are optimized to provide a highly thermal conductive carbon fiber/boron carbide composite material. In addition, carbide or boride type short fibers, spherical graphite, and amorphous carbon are mixed in the boron carbide to prevent development of cracks. Diffusion or solid solubilization of boron to carbon fibers is reduced or reaction of them if the carbon fibers are bundled. (N.H.)

Optic Nerve Disorders

Science.gov (United States)

The optic nerve is a bundle of more than 1 million nerve fibers that carry visual messages. You have one connecting ... retina) to your brain. Damage to an optic nerve can cause vision loss. The type of vision ...

Reconstruction of the abdominal vagus nerve using sural nerve grafts in canine models.

Science.gov (United States)

Liu, Jingbo; Wang, Jun; Luo, Fen; Wang, Zhiming; Wang, Yin

2013-01-01

Recently, vagus nerve preservation or reconstruction of vagus has received increasing attention. The present study aimed to investigate the feasibility of reconstructing the severed vagal trunk using an autologous sural nerve graft. Ten adult Beagle dogs were randomly assigned to two groups of five, the nerve grafting group (TG) and the vagal resection group (VG). The gastric secretion and emptying functions in both groups were assessed using Hollander insulin and acetaminophen tests before surgery and three months after surgery. All dogs underwent laparotomy under general anesthesia. In TG group, latency and conduction velocity of the action potential in a vagal trunk were measured, and then nerves of 4 cm long were cut from the abdominal anterior and posterior vagal trunks. Two segments of autologous sural nerve were collected for performing end-to-end anastomoses with the cut ends of vagal trunk (8-0 nylon suture, 3 sutures for each anastomosis). Dogs in VG group only underwent partial resections of the anterior and posterior vagal trunks. Laparotomy was performed in dogs of TG group, and latency and conduction velocity of the action potential in their vagal trunks were measured. The grafted nerve segment was removed, and stained with anti-neurofilament protein and toluidine blue. Latency of the action potential in the vagal trunk was longer after surgery than before surgery in TG group, while the conduction velocity was lower after surgery. The gastric secretion and emptying functions were weaker after surgery in dogs of both groups, but in TG group they were significantly better than in VG group. Anti-neurofilament protein staining and toluidine blue staining showed there were nerve fibers crossing the anastomosis of the vagus and sural nerves in dogs of TG group. Reconstruction of the vagus nerve using the sural nerve is technically feasible.

Reconstruction of the abdominal vagus nerve using sural nerve grafts in canine models.

Directory of Open Access Journals (Sweden)

Jingbo Liu

Full Text Available BACKGROUND: Recently, vagus nerve preservation or reconstruction of vagus has received increasing attention. The present study aimed to investigate the feasibility of reconstructing the severed vagal trunk using an autologous sural nerve graft. METHODS: Ten adult Beagle dogs were randomly assigned to two groups of five, the nerve grafting group (TG and the vagal resection group (VG. The gastric secretion and emptying functions in both groups were assessed using Hollander insulin and acetaminophen tests before surgery and three months after surgery. All dogs underwent laparotomy under general anesthesia. In TG group, latency and conduction velocity of the action potential in a vagal trunk were measured, and then nerves of 4 cm long were cut from the abdominal anterior and posterior vagal trunks. Two segments of autologous sural nerve were collected for performing end-to-end anastomoses with the cut ends of vagal trunk (8-0 nylon suture, 3 sutures for each anastomosis. Dogs in VG group only underwent partial resections of the anterior and posterior vagal trunks. Laparotomy was performed in dogs of TG group, and latency and conduction velocity of the action potential in their vagal trunks were measured. The grafted nerve segment was removed, and stained with anti-neurofilament protein and toluidine blue. RESULTS: Latency of the action potential in the vagal trunk was longer after surgery than before surgery in TG group, while the conduction velocity was lower after surgery. The gastric secretion and emptying functions were weaker after surgery in dogs of both groups, but in TG group they were significantly better than in VG group. Anti-neurofilament protein staining and toluidine blue staining showed there were nerve fibers crossing the anastomosis of the vagus and sural nerves in dogs of TG group. CONCLUSION: Reconstruction of the vagus nerve using the sural nerve is technically feasible.

[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

142 Key words: Brachialis, radial nerve, musculocutaneous nerve.

African Journals Online (AJOL)

AWORI KIRSTEEN

The innervation of brachialis muscle by the musculocutaneous nerve has been described as either type I or type II and the main trunk to this muscle is rarely absent. The contribution .... brachialis muscle by fiber analysis of supply nerves].

Effect of α-lipoic acid combined with nerve growth factor on bone metabolism, oxidative stress and nerve conduction function after femoral fracture surgery

Directory of Open Access Journals (Sweden)

An-Jun Cao

2017-11-01

Full Text Available Objective: To discuss the effect of 毩 -lipoic acid combined with nerve growth factor on bone metabolism, oxidative stress and nerve conduction function after femoral fracture surgery. Methods: A total of 110 patients with femoral fracture who received surgical treatment in the hospital between January 2015 and January 2017 were collected and divided into the control group (n=55 and study group (n=55 by random number table. Control group received postoperative nerve growth factor therapy, and study group received postoperative 毩 -lipoic acid combined with nerve growth factor therapy. The differences in the contents of bone metabolism and oxidative stress indexes as well as the levels of nerve conduction function indexes were compared between the two groups before and after treatment. Results: Before treatment, the differences in the contents of bone metabolism and oxidative stress indexes as well as the levels of nerve conduction function indexes were not statistically significant between the two groups. After treatment, serum bone metabolism indexes BGP and PⅠNP contents of study group were higher than those of control group while CTX-Ⅰ and TRAP contents were lower than those of control group; serum oxidative stress indexes TAC, CAT and SOD contents of study group were higher than those of control group while MDA content was lower than that of control group; limb nerve conduction velocity SCV and MCV levels of study group were higher than those of control group. Conclusion: 毩 -lipoic acid combined with nerve growth factor therapy after femoral fracture surgery can effectively balance osteoblast/ osteoclast activity, reduce oxidative stress and improve limb nerve conduction velocity.

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

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

-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......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...

Sensory nerve conduction in the caudal nerves of rats with diabetes Condução nervosa sensorial no nervo caudal de ratos com diabetes experimental

OpenAIRE

Celina Cordeiro de Carvalho; Juliana Netto Maia; Otávio Gomes Lins; Sílvia Regina Arruda de Moraes

2011-01-01

PURPOSE: To investigate sensory nerve conduction of the caudal nerve in normal and diabetic rats. METHODS: Diabetes was induced in twenty 8-weeks old Wistar male rats. Twenty normal rats served as controls. Caudal nerve conduction studies were made before diabetes induction and the end of each week for six consecutive weeks. The caudal nerve was stimulated distally and nerve potentials were recorded proximally on the animal's tail using common "alligator" clips as surface electrodes. RESULTS:...

Soft capacitor fibers using conductive polymers for electronic textiles

Science.gov (United States)

Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

2010-11-01

A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60-100 nF m-1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L-1, which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage.

Soft capacitor fibers using conductive polymers for electronic textiles

International Nuclear Information System (INIS)

Gu, Jian Feng; Gorgutsa, Stephan; Skorobogatiy, Maksim

2010-01-01

A novel, highly flexible, conductive polymer-based fiber with high electric capacitance is reported. In its cross section the fiber features a periodic sequence of hundreds of conductive and isolating plastic layers positioned around metallic electrodes. The fiber is fabricated using the fiber drawing method, where a multi-material macroscopic preform is drawn into a sub-millimeter capacitor fiber in a single fabrication step. Several kilometers of fibers can be obtained from a single preform with fiber diameters ranging between 500 and 1000 µm. A typical measured capacitance of our fibers is 60–100 nF m −1 and it is independent of the fiber diameter. Analysis of the fiber frequency response shows that in its simplest interrogation mode the capacitor fiber has a transverse resistance of 5 kΩ m L −1 , which is inversely proportional to the fiber length L and is independent of the fiber diameter. Softness of the fiber materials, the absence of liquid electrolyte in the fiber structure, ease of scalability to large production volumes and high capacitance of our fibers make them interesting for various smart textile applications ranging from distributed sensing to energy storage

Anatomical feasibility of vagus nerve esophageal branch transfer to the phrenic nerve☆

Science.gov (United States)

Wang, Ce; Liu, Jun; Yuan, Wen; Zhou, Xuhui; Wang, Xinwei; Xu, Peng; Chen, Jian; Wu, Guoxin; Shi, Sheng

2012-01-01

This study measured the vagus and phrenic nerves from 12 adult cadavers. We found that the width and thickness of the vagus and phrenic nerves were different in the chest. The distance from the point of the vagus nerve and phrenic nerve on the plane of the inferior border of portal pulmonary arteries (T point) was approximately 7 cm to the diaphragm and was approximately 10 cm to the clavicle level. The number of motor fibers in the vagus nerves was 1 716 ± 362, and the number of nerve fibers was 4 473 ± 653. The number of motor fibers in the phrenic nerves ranged from 3 078 ± 684 to 4 794 ± 638, and the number of nerve fibers ranged from 3 437 ± 642 to 5 071 ± 723. No significant difference was found in the total number of nerve fibers. The results suggest that width, thickness, and total number of nerve fibers are similar between the vagus and phrenic nerves, but the number of motor fibers is different between them. PMID:25745467

Retinal Nerve Fiber Layer Converges More Convexly on Normal Smaller Optic Nerve Head.

Science.gov (United States)

Jung, Kyoung In; Shin, Jeong Ah; Park, Hae-Young Lopilly; Park, Chan Kee

2015-08-01

To investigate retinal nerve fiber layer (RNFL) configuration in the optic nerve head (ONH) and peripapillary area according to disc size and to determine whether it explains cup discrepancy among eyes with different disc sizes. Horizontal and vertical RNFL curvature and mean thickness were measured using confocal scanning laser ophthalmoscopy (Heidelberg Retina Tomograph) in 63 normal subjects grouped by disc size. Average and quadrant RNFL thickness, disc size, average cup-to-disc ratio (CDR), and convergence angle at the optic disc were also measured using Cirrus HD-optical coherence tomography. The relationships between disc size and RNFL curvature, thickness, angle at optic disc, and CDR were evaluated. RNFL curvature and convergence angle reflects convexity "on" and "into" the optic disc, respectively. CDR was smaller for small discs and was positively correlated with disc size (Poptic disc were positively correlated with disc size (POptic disc area was negatively correlated with mean RNFL thickness at the optic disc margin measured by HRT (P=0.002), but not in the peripapillary area by optical coherence tomography. Using imaging techniques, we demonstrated that the shape of the RNFLs converging "on" and entering "into" the optic disc was more convex for small optic discs compared with large discs. A low CDR for small discs could be mediated by these RNFL profiles at the ONH, which may guide the clinical evaluation of glaucomatous ONH damage.

Structure-function relationships with spectral-domain optical coherence tomography retinal nerve fiber layer and optic nerve head measurements.

Science.gov (United States)

Pollet-Villard, Frédéric; Chiquet, Christophe; Romanet, Jean-Paul; Noel, Christian; Aptel, Florent

2014-05-02

To evaluate the regional structure-function relationship between visual field sensitivity and retinal nerve fiber layer (RNFL) thickness and optic nerve head (ONH) measurements using spectral-domain optical coherence tomography (SD-OCT). Prospective cross-sectional study conducted on patients with glaucoma, suspected glaucoma, and healthy subjects. Eyes were tested on Cirrus OCT and standard achromatic perimetry. RNFL thickness of 12 peripapillary 30° sectors, neuroretinal rim thickness extracted from 36 neuroretinal rim scans, and Bruch membrane opening minimum rim width (BMO-MRW)-a recently defined parameter-extracted from 36 neuroretinal rim scans were obtained. Correlations between peripapillary RNFL thickness, neuroretinal rim thickness, all six sectors of BMO-MRW, and visual field sensitivity in the six corresponding areas were evaluated using logarithmic regression analysis. Receiver operating curve areas were calculated for each RNFL, ONH, and macular ganglion cell analysis parameter. We included 142 eyes of 142 subjects. The correlations (r(2)) between RNFL thickness, Cirrus-based neuroretinal rim thickness, BMO-MRW and visual field sensitivity ranged from 0.07 to 0.60, 0.15 to 0.49, and 0.24 to 0.66, respectively. The structure-function correlations were stronger with BMO-MRW than with Cirrus-based neuroretinal rim thickness. The largest areas under the receiver operating curve were seen for rim area (0.926 [95% confidence interval 0.875, 0.977]; P function relationship was significantly stronger with BMO-MRW than other ONH SD-OCT parameters. The best diagnostic capabilities were seen with rim area and average RNFL.

Correlation Function Analysis of Fiber Networks: Implications for Thermal Conductivity

Science.gov (United States)

Martinez-Garcia, Jorge; Braginsky, Leonid; Shklover, Valery; Lawson, John W.

2011-01-01

The heat transport in highly porous fiber structures is investigated. The fibers are supposed to be thin, but long, so that the number of the inter-fiber connections along each fiber is large. We show that the effective conductivity of such structures can be found from the correlation length of the two-point correlation function of the local conductivities. Estimation of the parameters, determining the conductivity, from the 2D images of the structures is analyzed.

Engineering a multimodal nerve conduit for repair of injured peripheral nerve

Science.gov (United States)

Quigley, A. F.; Bulluss, K. J.; Kyratzis, I. L. B.; Gilmore, K.; Mysore, T.; Schirmer, K. S. U.; Kennedy, E. L.; O'Shea, M.; Truong, Y. B.; Edwards, S. L.; Peeters, G.; Herwig, P.; Razal, J. M.; Campbell, T. E.; Lowes, K. N.; Higgins, M. J.; Moulton, S. E.; Murphy, M. A.; Cook, M. J.; Clark, G. M.; Wallace, G. G.; Kapsa, R. M. I.

2013-02-01

Injury to nerve tissue in the peripheral nervous system (PNS) results in long-term impairment of limb function, dysaesthesia and pain, often with associated psychological effects. Whilst minor injuries can be left to regenerate without intervention and short gaps up to 2 cm can be sutured, larger or more severe injuries commonly require autogenous nerve grafts harvested from elsewhere in the body (usually sensory nerves). Functional recovery is often suboptimal and associated with loss of sensation from the tissue innervated by the harvested nerve. The challenges that persist with nerve repair have resulted in development of nerve guides or conduits from non-neural biological tissues and various polymers to improve the prognosis for the repair of damaged nerves in the PNS. This study describes the design and fabrication of a multimodal controlled pore size nerve regeneration conduit using polylactic acid (PLA) and (PLA):poly(lactic-co-glycolic) acid (PLGA) fibers within a neurotrophin-enriched alginate hydrogel. The nerve repair conduit design consists of two types of PLGA fibers selected specifically for promotion of axonal outgrowth and Schwann cell growth (75:25 for axons; 85:15 for Schwann cells). These aligned fibers are contained within the lumen of a knitted PLA sheath coated with electrospun PLA nanofibers to control pore size. The PLGA guidance fibers within the nerve repair conduit lumen are supported within an alginate hydrogel impregnated with neurotrophic factors (NT-3 or BDNF with LIF, SMDF and MGF-1) to provide neuroprotection, stimulation of axonal growth and Schwann cell migration. The conduit was used to promote repair of transected sciatic nerve in rats over a period of 4 weeks. Over this period, it was observed that over-grooming and self-mutilation (autotomy) of the limb implanted with the conduit was significantly reduced in rats implanted with the full-configuration conduit compared to rats implanted with conduits containing only an alginate

Cutaneous somatic and autonomic nerve TDP-43 deposition in amyotrophic lateral sclerosis.

Science.gov (United States)

Ren, Yuting; Liu, Wenxiu; Li, Yifan; Sun, Bo; Li, Yanran; Yang, Fei; Wang, Hongfen; Li, Mao; Cui, Fang; Huang, Xusheng

2018-05-26

To evaluate the involvement of the sensory and autonomic nervous system in amyotrophic lateral sclerosis (ALS) and to determine whether TDP-43/pTDP-43 deposits in skin nerve fibers signify a valuable biomarker for ALS. Eighteen patients with ALS and 18 age- and sex-matched control subjects underwent physical examinations, in addition to donating skin biopsies from the distal leg. The density of epidermal, Meissner's corpuscle (MC), sudomotor, and pilomotor nerve fibers were measured. Confocal microscopy was used to determine the cutaneous somatic and autonomic nerve fiber density and TDP-43/pTDP-43 deposition. Intraepidermal nerve fiber density (IENFD) was reduced in individuals with ALS (P nerve fiber density (SGNFD) (P nerve fiber density (PNFD) (P nerve fibers may indicate an important role in the underlying pathogenesis of ALS. This observation might be used as a potential biomarker for diagnosing ALS.

The influence of botulinum toxin type A (BTX) on the immunohistochemical characteristics of noradrenergic and cholinergic nerve fibers supplying the porcine urinary bladder wall.

Science.gov (United States)

Lepiarczyk, E; Bossowska, A; Kaleczyc, J; Majewski, M

2011-01-01

Botulinum toxin (BTX) belongs to a family of neurotoxins which strongly influence the function of autonomic neurons supplying the urinary bladder. Accordingly, BTX has been used as an effective drug in experimental therapies of a range of neurogenic bladder disorders. However, there is no detailed information dealing with the influence of BTX on the morphological and chemical properties of nerve fibres supplying the urinary bladder wall. Therefore, the present study investigated, using double-labeling immunohistochemistry, the distribution, relative frequency and chemical coding of cholinergic and noradrenergic nerve fibers supplying the wall of the urinary bladder in normal female pigs (n = 6) and in the pigs (n = 6) after intravesical BTX injections. In the pigs injected with BTX, the number of adrenergic (DbetaH-positive) nerve fibers distributed in the bladder wall (urothelium, submucosa and muscle coat) was distinctly higher while the number of cholinergic (VAChT-positive) nerve terminals was lower than that found in the control animals. Moreover, the injections of BTX resulted in some changes dealing with the chemical coding of the adrenergic nerve fibers. In contrast to the normal pigs, in BTX injected animals the number of DbetaH/NPY- or DbetaH/CGRP-positive axons was higher in the muscle coat, and some fibres distributed in the urothelium and submucosa expressed immunoreactivity to CGRP. The results obtained suggest that the therapeutic effects of BTX on the urinary bladder might be dependent on changes in the distribution and chemical coding of nerve fibers supplying this organ.

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…

Sleeve bridging of the rhesus monkey ulnar nerve with muscular branches of the pronator teres: multiple amplification of axonal regeneration

Directory of Open Access Journals (Sweden)

Yu-hui Kou

2015-01-01

Full Text Available Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previous studies have verified the limit and validity of multiple amplification of peripheral nerve regeneration using small gap sleeve bridging of small donor nerves to repair large receptor nerves in rodents. The present study sought to observe multiple amplification of myelinated nerve fiber regeneration in the primate peripheral nerve. Rhesus monkey models of distal ulnar nerve defects were established and repaired using muscular branches of the right forearm pronator teres. Proximal muscular branches of the pronator teres were sutured into the distal ulnar nerve using the small gap sleeve bridging method. At 6 months after suture, two-finger flexion and mild wrist flexion were restored in the ulnar-sided injured limbs of rhesus monkey. Neurophysiological examination showed that motor nerve conduction velocity reached 22.63 ± 6.34 m/s on the affected side of rhesus monkey. Osmium tetroxide staining demonstrated that the number of myelinated nerve fibers was 1,657 ± 652 in the branches of pronator teres of donor, and 2,661 ± 843 in the repaired ulnar nerve. The rate of multiple amplification of regenerating myelinated nerve fibers was 1.61. These data showed that when muscular branches of the pronator teres were used to repair ulnar nerve in primates, effective regeneration was observed in regenerating nerve fibers, and functions of the injured ulnar nerve were restored to a certain extent. Moreover, multiple amplification was subsequently detected in ulnar nerve axons.

Sleeve bridging of the rhesus monkey ulnar nerve with muscular branches of the pronator teres: multiple amplification of axonal regeneration.

Science.gov (United States)

Kou, Yu-Hui; Zhang, Pei-Xun; Wang, Yan-Hua; Chen, Bo; Han, Na; Xue, Feng; Zhang, Hong-Bo; Yin, Xiao-Feng; Jiang, Bao-Guo

2015-01-01

Multiple-bud regeneration, i.e., multiple amplification, has been shown to exist in peripheral nerve regeneration. Multiple buds grow towards the distal nerve stump during proximal nerve fiber regeneration. Our previous studies have verified the limit and validity of multiple amplification of peripheral nerve regeneration using small gap sleeve bridging of small donor nerves to repair large receptor nerves in rodents. The present study sought to observe multiple amplification of myelinated nerve fiber regeneration in the primate peripheral nerve. Rhesus monkey models of distal ulnar nerve defects were established and repaired using muscular branches of the right forearm pronator teres. Proximal muscular branches of the pronator teres were sutured into the distal ulnar nerve using the small gap sleeve bridging method. At 6 months after suture, two-finger flexion and mild wrist flexion were restored in the ulnar-sided injured limbs of rhesus monkey. Neurophysiological examination showed that motor nerve conduction velocity reached 22.63 ± 6.34 m/s on the affected side of rhesus monkey. Osmium tetroxide staining demonstrated that the number of myelinated nerve fibers was 1,657 ± 652 in the branches of pronator teres of donor, and 2,661 ± 843 in the repaired ulnar nerve. The rate of multiple amplification of regenerating myelinated nerve fibers was 1.61. These data showed that when muscular branches of the pronator teres were used to repair ulnar nerve in primates, effective regeneration was observed in regenerating nerve fibers, and functions of the injured ulnar nerve were restored to a certain extent. Moreover, multiple amplification was subsequently detected in ulnar nerve axons.

Electron microscopic study of the myelinated nerve fibres and the perineurial cell basement membrane in the diabetic human peripheral nerves

International Nuclear Information System (INIS)

ElBarrany, Wagih G.; Hamdy, Raid M.; AlHayani, Abdulmonem A.; Jalalah, Sawsan M.

2009-01-01

To study the quantitative and ultrastructural changes in myelinated nerve fibers and the basement membranes of the perineurial cells in diabetic nerves. The study was performed at the Department of Anatomy, Faculty of Medicine, King Abdul-Aziz University, Jeddah, Saudi Arabia from 2003 to 2005. Human sural nerves were obtained from 15 lower limbs and 5 diabetic nerve biopsies. The total mean and density of myelinated nerve fibers per fascicle were calculated, with density of microtubules and mitochondria in the axoplasm. The number of the perineurial cell basement membrane layers was counted, and thickness of the basement membrane was measured. Among the 15 diabetic and 5 normal human sural nerves, the average diameters, number and surface area of myelinated nerve fibers and axonal microtubules density were found to be less in diabetic nerves. Mitochondrial density was higher in diabetic axons. Thickness of the perineurial cell basement membrane had a greater mean, but the number of perineurial cell layers was less than that of the diabetic group. The inner cellular layer of the perineurium of the diabetic nerves contained large vacuoles containing electron-dense degenerated myelin. A few specimens showed degenerated myelinated nerve fibers, while others showed recovering ones. Retracted axoplasms were encountered with albumin extravasation. Diabetes caused an increase in perineurial permeability. The diabetic sural nerve showed marked decrease in the myelinated nerve fibres, increase degenerated mitochondria, and decreased microtubules. (author)

Electrically conductive biodegradable polymer composite for nerve regeneration: electricity-stimulated neurite outgrowth and axon regeneration.

Science.gov (United States)

Zhang, Ze; Rouabhia, Mahmoud; Wang, Zhaoxu; Roberge, Christophe; Shi, Guixin; Roche, Phillippe; Li, Jiangming; Dao, Lê H

2007-01-01

Normal and electrically stimulated PC12 cell cultures and the implantation of nerve guidance channels were performed to evaluate newly developed electrically conductive biodegradable polymer composites. Polypyrrole (PPy) doped by butane sulfonic acid showed a significantly higher number of viable cells compared with PPy doped by polystyrenesulfonate after a 6-day culture. The PC12 cells were left to proliferate for 6 days, and the PPy-coated membranes, showing less initial cell adherence, recorded the same proliferation rate as did the noncoated membranes. Direct current electricity at various intensities was applied to the PC12 cell-cultured conductive membranes. After 7 days, the greatest number of neurites appeared on the membranes with a current intensity approximating 1.7-8.4 microA/cm. Nerve guidance channels made of conductive biodegradable composite were implanted into rats to replace 8 mm of sciatic nerve. The implants were harvested after 2 months and analyzed with immunohistochemistry and transmission electron microscopy. The regenerated nerve tissue displayed myelinated axons and Schwann cells that were similar to those in the native nerve. Electrical stimulation applied through the electrically conductive biodegradable polymers therefore enhanced neurite outgrowth in a current-dependent fashion. The conductive polymers also supported sciatic nerve regeneration in rats.

Potential Role of In Vivo Confocal Microscopy for Imaging Corneal Nerves in Transthyretin Familial Amyloid Polyneuropathy.

Science.gov (United States)

Rousseau, Antoine; Cauquil, Cecile; Dupas, Benedicte; Labbé, Antoine; Baudouin, Christophe; Barreau, Emmanuel; Théaudin, Marie; Lacroix, Catherine; Guiochon-Mantel, Anne; Benmalek, Anouar; Labetoulle, Marc; Adams, David

2016-09-01

Small fiber neuropathy (SFN) is an important feature of transthyretin familial amyloid polyneuropathy (TTR-FAP). A practical and objective method for the clinical evaluation of SFN is needed to improve the management of this disease. In vivo confocal microscopy (IVCM) of the corneal nerves, a rapid noninvasive technique, may be used as a surrogate marker of SFN. To determine the correlation of SFN with IVCM in patients with TTR-FAP. A prospective, single-center, cross-sectional controlled study was conducted at the French National Reference Center for TTR-FAP from June 1, 2013, to June 30, 2014. Fifteen patients with TTR-FAP underwent a complete neurologic examination, including Neuropathy Impairment Score of the Lower Limbs, hand grip strength, and evaluation of vegetative dysfunction, as well as electrophysiologic studies (nerve conduction and electrochemical skin conductance) and intraepidermal nerve fiber density quantification. Patients and 15 controls (matched for age and sex) underwent ophthalmologic assessments, including corneal esthesiometry and IVCM. Correlation of corneal nerve fiber length (CNFL) with the severity of SFN. Of the 15 patients enrolled in the study, 6 were women (40%); mean (SD) age was 54.4 [13.7] years. The CNFL was shorter in the patients than in controls (13.08 vs 17.57 mm/mm2; difference of 4.49 [95% CI, 0.72 to 8.27]; P = .02). The patients' CNFL correlated with the severity of both autonomic neuropathy assessed by the Compound Autonomic Dysfunction Test (rs = 0.66 [95% CI, 0.22 to 0.87]; P = .008) or electrochemical skin conductance (rs = 0.80 [95% CI, 0.50 to 0.93]; P < .001) and sensorimotor neuropathy assessed using the Neuropathy Impairment Score of the Lower Limbs (rs = -0.58 [95% CI, -0.84 to -0.11]; P = .02). Patients with altered sensory nerve action potentials and intraepidermal nerve fiber density had a shorter CNFL (P = .04 and P = .02, respectively). The CNFL could be measured in all

Conduction noise absorption by fiber-reinforced epoxy composites with carbon nanotubes

International Nuclear Information System (INIS)

Lee, Ok Hyoung; Kim, Sung-Soo; Lim, Yun-Soo

2011-01-01

Nearly all electronic equipment is susceptible to malfunction as a result of electromagnetic interference. In this study, glass fiber, and carbon fiber as a type reinforcement and epoxy as a matrix material were used to fabricate composite materials. In an attempt to increase the conduction noise absorption, carbon nanotubes were grown on the surface of glass fibers and carbon fibers. A microstrip line with characteristic impedance of 50 Ω in connection with network analyzer was used to measure the conduction noise absorption. In comparing a glass fiber/epoxy composite with a GF-CNT/Ep composite, it was demonstrated that the CNTs significantly influence the noise absorption property mainly due to increase in electric conductivity. In the carbon fiber composites, however, the effectiveness of CNTs on the degree of electric conductivity is negligible, resulting in a small change in reflection and transmission of an electromagnetic wave. - Research Highlights: → In this study, glass fiber and carbon fiber as a type reinforcement and epoxy as a matrix material were used to fabricate composite materials. In an attempt to increase the conduction noise absorption, carbon nanotubes (CNTs) were grown on the surface of glass fibers and carbon fibers. A microstrip line with characteristic impedance of 50 Ω in connection with network analyzer was used to measure the conduction noise absorption. → In comparing a glass fiber/epoxy composite with a GF-CNT/Ep composite, it was demonstrated that the CNTs significantly influence the noise absorption property mainly due to increase in electric conductivity. In the carbon fiber composites, however, the effectiveness of CNTs on the degree of electric conductivity is negligible, resulting in a small change in reflection and transmission of an electromagnetic wave.

Electrophysiologic alterations in the excitability of the sciatic and vagus nerves during early stages of sepsis.

Science.gov (United States)

Diniz, Lúcio Ricardo Leite; Portella, Viviane Gomes; da Silva Alves, Kerly Shamira; Araújo, Pâmella Cristina da Costa; de Albuquerque Júnior, Ricardo Luiz Cavalcanti; Cavalcante de Albuquerque, Aline Alice; Coelho-de-Souza, Andrelina Noronha; Leal-Cardoso, José Henrique

2018-01-01

Nonspecific and delayed diagnosis of neurologic damage contributes to the development of neuropathies in patients with severe sepsis. The present study assessed the electrophysiologic parameters related to the excitability and conductibility of sciatic and vagus nerves during early stages of sepsis. Twenty-four hours after sepsis induced by cecal ligation and puncture (CLP) model, sciatic and vagus nerves of septic (CLP group) and control (sham group) rats were removed, and selected electric stimulations were applied to measure the parameters of the first and second components of the compound action potential. The first component originated from fibers with motor and sensory functions (Types A α and A β fibers) with a large conduction velocity (70-120 m/s), and the second component originated from fibers (Type A γ ) with sensorial function. To evaluate the presence of sensorial alterations, the sensitivity to non-noxious mechanical stimuli was measured by using the von Frey test. Hematoxylin and eosin staining of the nerves was performed. We observed an increase of rheobase followed by a decrease in the first component amplitude and a higher paw withdrawal threshold in response to the application of von Frey filaments in sciatic nerves from the CLP group compared to the sham group. Differently, a decrease in rheobase and an increase in the first component amplitude of vagal C fibers from CLP group were registered. No significant morphologic alteration was observed. Our data showed that the electrophysiologic alterations in peripheral nerves vary with the fiber type and might be identified in the first 24 h of sepsis, before clinical signs of neuromuscular disorders.

Temporary persistence of conduction block after prolonged kilohertz frequency alternating current on rat sciatic nerve

Science.gov (United States)

Bhadra, Narendra; Foldes, Emily; Vrabec, Tina; Kilgore, Kevin; Bhadra, Niloy

2018-02-01

Objective. Application of kilohertz frequency alternating current (KHFAC) waveforms can result in nerve conduction block that is induced in less than a second. Conduction recovers within seconds when KHFAC is applied for about 5-10 min. This study investigated the effect of repeated and prolonged application of KHFAC on rat sciatic nerve with bipolar platinum electrodes. Approach. Varying durations of KHFAC at signal amplitudes for conduction block with intervals of no stimulus were studied. Nerve conduction was monitored by recording peak Gastrocnemius muscle force utilizing stimulation electrodes proximal (PS) and distal (DS) to a blocking electrode. The PS signal traveled through the block zone on the nerve, while the DS went directly to the motor end-plate junction. The PS/DS force ratio provided a measure of conduction patency of the nerve in the block zone. Main results. Conduction recovery times were found to be significantly affected by the cumulative duration of KHFAC application. Peak stimulated muscle force returned to pre-block levels immediately after cessation of KHFAC delivery when it was applied for less than about 15 min. They fell significantly but recovered to near pre-block levels for cumulative stimulus of 50  ±  20 min, for the tested On/Off times and frequencies. Conduction recovered in two phases, an initial fast one (60-80% recovery), followed by a slower phase. No permanent conduction block was seen at the end of the observation period during any experiment. Significance. This carry-over block effect may be exploited to provide continuous conduction block in peripheral nerves without continuous application of KHFAC.

A novel method of lengthening the accessory nerve for direct coaptation during nerve repair and nerve transfer procedures.

Science.gov (United States)

Tubbs, R Shane; Maldonado, Andrés A; Stoves, Yolanda; Fries, Fabian N; Li, Rong; Loukas, Marios; Oskouian, Rod J; Spinner, Robert J

2018-01-01

OBJECTIVE The accessory nerve is frequently repaired or used for nerve transfer. The length of accessory nerve available is often insufficient or marginal (under tension) for allowing direct coaptation during nerve repair or nerve transfer (neurotization), necessitating an interpositional graft. An attractive maneuver would facilitate lengthening of the accessory nerve for direct coaptation. The aim of the present study was to identify an anatomical method for such lengthening. METHODS In 20 adult cadavers, the C-2 or C-3 connections to the accessory nerve were identified medial to the sternocleidomastoid (SCM) muscle and the anatomy of the accessory nerve/cervical nerve fibers within the SCM was documented. The cervical nerve connections were cut. Lengths of the accessory nerve were measured. Samples of the cut C-2 and C-3 nerves were examined using immunohistochemistry. RESULTS The anatomy and adjacent neural connections within the SCM are complicated. However, after the accessory nerve was "detethered" from within the SCM and following transection, the additional length of the accessory nerve increased from a mean of 6 cm to a mean of 10.5 cm (increase of 4.5 cm) after cutting the C-2 connections, and from a mean of 6 cm to a mean length of 9 cm (increase of 3.5 cm) after cutting the C-3 connections. The additional length of accessory nerve even allowed direct repair of an infraclavicular target (i.e., the proximal musculocutaneous nerve). The cervical nerve connections were shown not to contain motor fibers. CONCLUSIONS An additional length of the accessory nerve made available in the posterior cervical triangle can facilitate direct repair or neurotization procedures, thus eliminating the need for an interpositional nerve graft, decreasing the time/distance for regeneration and potentially improving clinical outcomes.

Recovery of the sub-basal nerve plexus and superficial nerve terminals after corneal epithelial injury in mice.

Science.gov (United States)

Downie, Laura E; Naranjo Golborne, Cecilia; Chen, Merry; Ho, Ngoc; Hoac, Cam; Liyanapathirana, Dasun; Luo, Carol; Wu, Ruo Bing; Chinnery, Holly R

2018-06-01

Our aim was to compare regeneration of the sub-basal nerve plexus (SBNP) and superficial nerve terminals (SNT) following corneal epithelial injury. We also sought to compare agreement when quantifying nerve parameters using different image analysis techniques. Anesthetized, female C57BL/6 mice received central 1-mm corneal epithelial abrasions. Four-weeks post-injury, eyes were enucleated and processed for PGP9.5 to visualize the corneal nerves using wholemount immunofluorescence staining and confocal microscopy. The percentage area of the SBNP and SNT were quantified using: ImageJ automated thresholds, ImageJ manual thresholds and manual tracings in NeuronJ. Nerve sum length was quantified using NeuronJ and Imaris. Agreement between methods was considered with Bland-Altman analyses. Four-weeks post-injury, the sum length of nerve fibers in the SBNP, but not the SNT, was reduced compared with naïve eyes. In the periphery, but not central cornea, of both naïve and injured eyes, nerve fiber lengths in the SBNP and SNT were strongly correlated. For quantifying SBNP nerve axon area, all image analysis methods were highly correlated. In the SNT, there was poor correlation between manual methods and auto-thresholding, with a trend towards underestimating nerve fiber area using auto-thresholding when higher proportions of nerve fibers were present. In conclusion, four weeks after superficial corneal injury, there is differential recovery of epithelial nerve axons; SBNP sum length is reduced, however the sum length of SNTs is similar to naïve eyes. Care should be taken when selecting image analysis methods to compare nerve parameters in different depths of the corneal epithelium due to differences in background autofluorescence. Copyright © 2018 Elsevier Ltd. All rights reserved.

Reversible acute axonal polyneuropathy associated with Wernicke-Korsakoff syndrome: impaired physiological nerve conduction due to thiamine deficiency?

Science.gov (United States)

Ishibashi, S; Yokota, T; Shiojiri, T; Matunaga, T; Tanaka, H; Nishina, K; Hirota, H; Inaba, A; Yamada, M; Kanda, T; Mizusawa, H

2003-05-01

Acute axonal polyneuropathy and Wernicke-Korsakoff encephalopathy developed simultaneously in three patients. Nerve conduction studies (NCS) detected markedly decreased compound muscle action potentials (CMAPs) and sensory nerve action potentials (SNAPs) with minimal conduction slowing; sympathetic skin responses (SSRs) were also notably decreased. Sural nerve biopsies showed only mild axonal degeneration with scattered myelin ovoid formation. The symptoms of neuropathy lessened within two weeks after an intravenous thiamine infusion. CMAPs, SNAPs, and SSRs also increased considerably. We suggest that this is a new type of peripheral nerve impairment: physiological conduction failure with minimal conduction delay due to thiamine deficiency.

Hypoxia-induced increases in serotonin-immunoreactive nerve fibers in the medulla oblongata of the rat.

Science.gov (United States)

Morinaga, Ryosuke; Nakamuta, Nobuaki; Yamamoto, Yoshio

2016-10-01

Hypoxia induces respiratory responses in mammals and serotonergic neurons in the medulla oblongata participate in respiratory control. However, the morphological changes in serotonergic neurons induced by hypoxia have not yet been examined and respiratory controls of serotonergic neurons have not been clarified. We herein investigated the distribution of immunoreactivity for serotonin (5-hydroxytryptamine; 5-HT) in the medulla oblongata of control rats and rats exposed to 1-6h of hypoxia (10% O 2 ). We also examined the medulla oblongata by multiple immunofluorescence labeling for 5-HT, neurokinin 1 receptors (NK1R), a marker for some respiratory neurons in the pre-Bötzinger complex (PBC), and dopamine β-hydroxylase (DBH), a marker for catecholaminergic neurons. The number of 5-HT-immunoreactive nerve cell bodies in the raphe nuclei was higher in rats exposed to hypoxia than in control rats. The number of 5-HT-immunoreactive nerve fibers significantly increased in the rostral ventrolateral medulla of rats exposed to 1-6h of hypoxia, caudal ventrolateral medulla of rats exposed to 2-6h of hypoxia, and lateral part of the nucleus of the solitary tract and dorsal motor nucleus of the vagus nerve of rats exposed to 1-2h of hypoxia. Multiple immunofluorescence labeling showed that 5-HT-immunoreactive nerve fibers were close to NK1R-immunoreactive neurons in ventrolateral medulla and to DBH-immunoreactive neurons in the medulla. These results suggest that serotonergic neurons partly regulate respiratory control under hypoxic conditions by modulating the activity of NK1R-expressing and catecholaminergic neurons. Copyright © 2016 Elsevier GmbH. All rights reserved.

Nerve endings in the heart of teleosts.

Science.gov (United States)

Kumar, S

1979-01-01

The nerve endings in the heart of fishes were studied using silver impregnation techniques. The heart chambers are profusely innervated by the sympathetic, parasympathetic (vagal) and postganglionic fibers of the intracardiac ganglia situated at the sinuatrial and the atrioventricular junctions. The plexuses are composed of medullated and nonmedullated fibers. The nerve fibers generally end freely and are slightly branched or unbranched terminations of myelinated and unmyelinated fibers. Moreover, a few nerve fibers end redundant in the form of end-rings, bulb-like, bush-like, club-shaped end end-coil like structures. The complex unencapsulated types of endings are also found in the myocardium of the atrium and the ventricle. The encapsulated endings (Vater-Pacinian; Krause end-bulb) could not be observed.

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...

[Glaucoma and optic nerve drusen: Limitations of optic nerve head OCT].

Science.gov (United States)

Poli, M; Colange, J; Goutagny, B; Sellem, E

2017-09-01

Optic nerve head drusen are congenital calcium deposits located in the prelaminar section of the optic nerve head. Their association with visual field defects has been classically described, but the diagnosis of glaucoma is not easy in these cases of altered optic nerve head anatomy. We describe the case of a 67-year-old man with optic nerve head drusen complicated by glaucoma, which was confirmed by visual field and OCT examination of the peripapillary retinal nerve fiber layer (RNFL), but the measurement of the minimum distance between the Bruch membrane opening and the internal limiting membrane (minimum rim width, BMO-MRW) by OCT was normal. OCT of the BMO-MRW is a new diagnostic tool for glaucoma. Superficial optic nerve head drusen, which are found between the internal limiting membrane and the Bruch's membrane opening, overestimate the value of this parameter. BMO-MRW measurement is not adapted to cases of optic nerve head drusen and can cause false-negative results for this parameter, and the diagnosis of glaucoma in this case should be based on other parameters such as the presence of a fascicular defect in the retinal nerve fibers, RNFL or macular ganglion cell complex thinning, as well as visual field data. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Development and evaluation of spatial point process models for epidermal nerve fibers.

Science.gov (United States)

Olsbo, Viktor; Myllymäki, Mari; Waller, Lance A; Särkkä, Aila

2013-06-01

We propose two spatial point process models for the spatial structure of epidermal nerve fibers (ENFs) across human skin. The models derive from two point processes, Φb and Φe, describing the locations of the base and end points of the fibers. Each point of Φe (the end point process) is connected to a unique point in Φb (the base point process). In the first model, both Φe and Φb are Poisson processes, yielding a null model of uniform coverage of the skin by end points and general baseline results and reference values for moments of key physiologic indicators. The second model provides a mechanistic model to generate end points for each base, and we model the branching structure more directly by defining Φe as a cluster process conditioned on the realization of Φb as its parent points. In both cases, we derive distributional properties for observable quantities of direct interest to neurologists such as the number of fibers per base, and the direction and range of fibers on the skin. We contrast both models by fitting them to data from skin blister biopsy images of ENFs and provide inference regarding physiological properties of ENFs. Copyright © 2013 Elsevier Inc. All rights reserved.

INTERPRETATION OF NERVE CONDUCTION STUDY IN POLYNEUROPATHY WITH MULTIBACILLARY LEPROSY TYPE 2 REACTION

Directory of Open Access Journals (Sweden)

Diane Tantia Sari

2018-04-01

Full Text Available Leprosy reaction contributes to disability due to peripheral nerve damage. Nerve conduction study (NCS provides a profound physiological description of peripheral nerves. This study aims to report a case of polyneuropathy in leprosy with type 2 reactions (T2R which is evaluated using NCS. A 33-year-old woman complain of painful bumps in her arms and legs, fever, swollen feet since 2 days ago, and history of leprosy. Dermatologic examination on the right superior palpebra, right and left arms and legs revealed multiple tenderness erythematous nodules; right claw hand; and both legs oedema. Slit skin smear revealed positive result. Histopathologic examination supported T2R description. The NCS examination concluded severe axonal demyelinating motoric sensoric polyneurophaty, with left worse. She was treated with MDT-MB, bed rest, orally methylprednisolone, vitamin B, paracetamol, ferrous sulfas, and topical olive oil. Clinical improvement was achieved after 2 weeks. The NCS is used to assess the nerve impuls conduction along the peripheral nerves. In this case, it was found that NCS could showed early neuropathy in nerves that were clinically undetectable. It can be concluded that the NCS examination is an important diagnostic modalities for early detection of neuropathy and confirmed the diagnosis of clinical neuropathy in leprosy.

Conductivity and Ambient Stability of Halogen-Doped Carbon Nanotube Fibers

Science.gov (United States)

Gaier, J. R.; Chirino, C. M.; Chen, M.; Waters, D. L.; Tran, Mai Kim; Headrick, R.; Young, C. C.; Tsentalovich, D.; Whiting, B.; Pasquali, M.;

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

The nerve endings of the acetabular labrum.

Science.gov (United States)

Kim, Y T; Azuma, H

1995-11-01

The nerve endings of the human acetabular labrum were investigated. Twenty-three acetabular labra were obtained from 24 fresh human cadavers, stained with Suzuki's silver impregnation and an immunohistochemical technique for neurogenic specific protein S-100, and examined by light and electron microscopy. Ramified free nerve endings were seen in all specimens by silver staining, and also were observed by the immunohistochemical technique for S-100 protein. Sensory nerve end organs, such as a Vater-Pacini corpuscle, Golgi-Mazzoni corpuscle, Ruffini corpuscle, and articular corpuscle (Krause corpuscle), were observed by silver staining. Collagen fibers were scattered sparsely in the superficial layer of the labrum, and nerve endings were observed mostly in this region. Collagen fibers were sparse, and nerve endings also were observed in some regions among the collagen fiber bundles in the inner layer. Innervation of the acetabular labrum was confirmed in this study, suggesting that nerve endings in the labrum may be involved in nociceptive and proprioceptive mechanisms.

Functional and structural microanatomy of the fetal sciatic nerve.

Science.gov (United States)

Creze, Maud; Zaitouna, Mazen; Krystel, Nyangoh Timoh; Diallo, Djibril; Lebacle, Cédric; Bellin, Marie-France; Ducreux, Denis; Benoit, Gérard; Bessede, Thomas

2017-10-01

The ultrastructure of a nerve has implications for surgical nerve repair. The aim of our study was to characterize the fascicular versus fibrillar anatomy and the autonomic versus somatic nature of the fetal sciatic nerve (SN). Immunohistochemistry for vesicular acetylcholine transporter, tyrosine hydroxylase, and peripheral myelin protein 22 was performed to identify cholinergic, adrenergic, and somatic axons, respectively, in the human fetal SN. Two-dimensional (2D) analysis and 3D reconstructions were performed. The fetal SN is composed of one-third stromal tissue and two-thirds neural tissue. Autonomic fibers are predominant over somatic fibers within the neural tissue. The distribution of somatic fibers is initially random, but then become topographically organized after intra- and interfascicular rearrangements have occurred within the nerve. The fetal model presents limitations but enables illustration of the nature of the nerve fibers and the 3D fascicular anatomy of the SN. Muscle Nerve 56: 787-796, 2017. © 2017 Wiley Periodicals, Inc.

Ultrastructural changes of compressed lumbar ventral nerve roots following decompression

International Nuclear Information System (INIS)

El-Barrany, Wagih G.; Hamdy, Raid M.; Al-Hayani, Abdulmonem A.; Jalalah, Sawsan M.; Al-Sayyad, Mohammad J.

2006-01-01

To study whether there will be permanent lumbar nerve rot scanning or degeneration secondary to continuous compression followed by decompression on the nerve roots, which can account for postlaminectomy leg weakness or back pain. The study was performed at the Department of Anatomy, Faulty of Medicine, king Abdulaziz University, Jeddah, Kingdom of Saudi Arabia during 2003-2005. Twenty-six adult male New Zealand rabbits were used in the present study. The ventral roots of the left fourth lumbar nerve were clamped for 2 weeks then decompression was allowed by removal of the clips. The left ventral roots of the fourth lumbar nerve were excised for electron microscopic study. One week after nerve root decompression, the ventral root peripheral to the site of compression showed signs of Wallerian degeneration together with signs of regeneration. Schwann cells and myelinated nerve fibers showed severe degenerative changes. Two weeks after decompression, the endoneurium of the ventral root showed extensive edema with an increase in the regenerating myelinated and unmyentilated nerve fibers, and fibroblasts proliferation. Three weeks after decompression, the endoneurium showed an increase in the regenerating myelinated and unmyelinated nerve fibers with diminution of the endoneurial edema, and number of macrophages and an increase in collagen fibrils. Five and 6 weeks after decompression, the endoneurium showed marked diminution of the edema, macrophages, mast cells and fibroblasts. The enoneurium was filed of myelinated and unmyelinated nerve fibers and collagen fibrils. Decompression of the compressed roots of a spinal nerve is followed by regeneration of the nerve fibers and nerve and nerve recovery without endoneurial scarring. (author)

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

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...... 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....

Imaging of the facial nerve

Energy Technology Data Exchange (ETDEWEB)

Veillon, F. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France)], E-mail: Francis.Veillon@chru-strasbourg.fr; Ramos-Taboada, L.; Abu-Eid, M. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France); Charpiot, A. [Service d' ORL, Hopital de Hautepierre, 67098 Strasbourg Cedex (France); Riehm, S. [Service de Radiologie I, Hopital de Hautepierre, 67098 Strasbourg Cedex (France)

2010-05-15

The facial nerve is responsible for the motor innervation of the face. It has a visceral motor function (lacrimal, submandibular, sublingual glands and secretion of the nose); it conveys a great part of the taste fibers, participates to the general sensory of the auricle (skin of the concha) and the wall of the external auditory meatus. The facial mimic, production of tears, nasal flow and salivation all depend on the facial nerve. In order to image the facial nerve it is mandatory to be knowledgeable about its normal anatomy including the course of its efferent and afferent fibers and about relevant technical considerations regarding CT and MR to be able to achieve high-resolution images of the nerve.

Preparation of ZnO nanorods on conductive PET-ITO-Ag fibers

Energy Technology Data Exchange (ETDEWEB)

Li, Yiwen; Ji, Shuai; Chen, Yuanyu; Zhang, Hong; Gong, Yumei, E-mail: ymgong@dlpu.edu.cn; Guo, Jing, E-mail: guojing8161@163.com

2016-12-01

Highlights: • Polymeric PET fibers were conductive modified by ITO and the subsequent Ag coating. The conductive PET-ITO-Ag fiber has the surface resistivity as low as 0.23 mΩ cm. The PET-ITO-Ag fiber was used as a basal material to plant vertical ZnO nanorods. - Abstract: We studied the vertical ZnO nanorods grown on conductive conventional polyethylene terephthalate (PET) fibers which are prepared by electroless silver depositing on tin-doped indium oxide (ITO) coated PET fibers through an efficient and low-cost green approach. The PET fibers were firstly functionalized with a layer of ITO gel synthesized through a sol–gel process at rather low temperature, simply by immersing the fibers into ITO sol for several minutes followed by gelation at 120 °C. Once the ITO gel layer surface was activated by SnCl{sub 2}, a continuous, uniform, and compact layer of silver was carried out on the surface of the PET-ITO fibers through electroless plating operation at room temperature. The as-prepared PET-ITO-Ag fibers had good electrical conductivity, with surface resistivity as low as 0.23 mΩ cm. The overall procedure is simple, efficient, nontoxic, and controllable. The conductive PET-ITO-Ag fiber was used successfully as a flexible basal material to plant vertical ZnO nanorods through controlling the seeding and growth processes. The morphology of the PET-ITO, PET-ITO-Ag, and PET-ITO-Ag-ZnO fibers were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Undergone the whole process, although the tensile strength of the fiber decreased slightly, they may still exert their applications in flexible electronic such as photovoltaic and piezoelectric devices.

Preparation of ZnO nanorods on conductive PET-ITO-Ag fibers

International Nuclear Information System (INIS)

Li, Yiwen; Ji, Shuai; Chen, Yuanyu; Zhang, Hong; Gong, Yumei; Guo, Jing

2016-01-01

Highlights: • Polymeric PET fibers were conductive modified by ITO and the subsequent Ag coating. The conductive PET-ITO-Ag fiber has the surface resistivity as low as 0.23 mΩ cm. The PET-ITO-Ag fiber was used as a basal material to plant vertical ZnO nanorods. - Abstract: We studied the vertical ZnO nanorods grown on conductive conventional polyethylene terephthalate (PET) fibers which are prepared by electroless silver depositing on tin-doped indium oxide (ITO) coated PET fibers through an efficient and low-cost green approach. The PET fibers were firstly functionalized with a layer of ITO gel synthesized through a sol–gel process at rather low temperature, simply by immersing the fibers into ITO sol for several minutes followed by gelation at 120 °C. Once the ITO gel layer surface was activated by SnCl 2 , a continuous, uniform, and compact layer of silver was carried out on the surface of the PET-ITO fibers through electroless plating operation at room temperature. The as-prepared PET-ITO-Ag fibers had good electrical conductivity, with surface resistivity as low as 0.23 mΩ cm. The overall procedure is simple, efficient, nontoxic, and controllable. The conductive PET-ITO-Ag fiber was used successfully as a flexible basal material to plant vertical ZnO nanorods through controlling the seeding and growth processes. The morphology of the PET-ITO, PET-ITO-Ag, and PET-ITO-Ag-ZnO fibers were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Undergone the whole process, although the tensile strength of the fiber decreased slightly, they may still exert their applications in flexible electronic such as photovoltaic and piezoelectric devices.

Normal axonal ion channel function in large peripheral nerve fibers following chronic ciguatera sensitization.

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Vucic, Steve; Kiernan, Matthew C

2008-03-01

Although the acute clinical effects of ciguatera poisoning, due to ingestion of ciguatoxin, are mediated by activation of transient Na+ channels, the mechanisms underlying ciguatera sensitization remain undefined. Axonal excitability studies were performed by stimulating the median motor and sensory nerves in two patients with ciguatera sensitization. Excitability parameters were all within normal limits, thereby arguing against dysfunction of axonal membrane ion channels in large-diameter fibers in ciguatera sensitization.

Thermal conductivity of high performance carbon nanotube yarn-like fibers

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Mayhew, Eric; Prakash, Vikas, E-mail: vikas.prakash@case.edu [Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7222 (United States)

2014-05-07

In the present paper, we present results of thermal conductivity measurements in free standing carbon nanotube (CNT) yarn-like fibers. The measurements are made using a T-type experimental configuration utilizing a Wollaston-wire hot probe inside a scanning electron microscope. In this technique, a suspended platinum wire is used both as a heater and a thermal sensor. A low frequency alternating current source is used to heat the probe wire while the third harmonic voltage across the wire is measured by a lock-in amplifier. The conductivity is deduced from an analytical model that relates the drop in the spatially averaged temperature of the wire to that of the sample. The average thermal conductivity of the neat CNT fibers and the CNT –polymer composite fibers is found to be 448 W/m-K and 225 W/m-K, respectively. These values for conductivity are amongst the highest measured for CNT yarn-like fibers fabricated using a dry spinning process from vertically aligned CNT arrays. The enhancement in thermal conductivity is understood to be due to an increase in the CNT fiber elastic stiffness during the draw and twist operations, lower CNT thermal contact resistance due to increase in CNT contact area, and better alignment of the CNT fibrils along the length of the fiber.

Acellular Nerve Allografts in Peripheral Nerve Regeneration: A Comparative Study

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Moore, Amy M.; MacEwan, Matthew; Santosa, Katherine B.; Chenard, Kristofer E.; Ray, Wilson Z.; Hunter, Daniel A.; Mackinnon, Susan E.; Johnson, Philip J.

2011-01-01

Background Processed nerve allografts offer a promising alternative to nerve autografts in the surgical management of peripheral nerve injuries where short deficits exist. Methods Three established models of acellular nerve allograft (cold-preserved, detergent-processed, and AxoGen® -processed nerve allografts) were compared to nerve isografts and silicone nerve guidance conduits in a 14 mm rat sciatic nerve defect. Results All acellular nerve grafts were superior to silicone nerve conduits in support of nerve regeneration. Detergent-processed allografts were similar to isografts at 6 weeks post-operatively, while AxoGen®-processed and cold-preserved allografts supported significantly fewer regenerating nerve fibers. Measurement of muscle force confirmed that detergent-processed allografts promoted isograft-equivalent levels of motor recovery 16 weeks post-operatively. All acellular allografts promoted greater amounts of motor recovery compared to silicone conduits. Conclusions These findings provide evidence that differential processing for removal of cellular constituents in preparing acellular nerve allografts affects recovery in vivo. PMID:21660979

Neurotization of the phrenic nerve with accessory nerve for high cervical spinal cord injury with respiratory distress: an anatomic study.

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Wang, Ce; Zhang, Ying; Nicholas, Tsai; Wu, Guoxin; Shi, Sheng; Bo, Yin; Wang, Xinwei; Zhou, Xuhui; Yuan, Wen

2014-01-01

High cervical spinal cord injury is associated with high morbidity and mortality. Traditional treatments carry various complications such as infection, pacemaker failure and undesirable movement. Thus, a secure surgical strategy with fewer complications analogous to physiological ventilation is still required. We hope to offer one potential method to decrease the complications and improve survival qualities of patients from the aspect of anatomy. The purpose of the study is to provide anatomic details on the accessory nerve and phrenic nerve for neurotization in patients with high spinal cord injuries. 38 cadavers (76 accessory and 76 phrenic nerves) were dissected in the study. The width, length and thickness of each accessory nerve and phrenic nerve above clavicle were measured. The distances from several landmarks on accessory nerve to the origin and the end of the phrenic nerve above clavicle were measured too. Then, the number of motor nerve fibers on different sections of the nerves was calculated using the technique of immunohistochemistry. The accessory nerves distal to its sternocleidomastoid muscular branches were 1.52 ± 0.32 mm ~1.54 ± 0.29 mm in width, 0.52 ± 0.18 mm ~ 0.56 ± 0.20mm in thickness and 9.52 ± 0.98 cm in length. And the phrenic nerves above clavicle were 1.44 ± 0.23 mm ~ 1.45 ± 0.24 mm in width, 0.47 ± 0.15 mm ~ 0.56 ± 0.25 mm in thickness and 6.48 ± 0.78 cm in length. The distance between the starting point of accessory nerve and phrenic nerve were 3.24 ± 1.17 cm, and the distance between the starting point of accessory nerve and the end of the phrenic nerve above clavicle were 8.72 ± 0.84 cm. The numbers of motor nerve fibers in accessory nerve were 1,038 ± 320~1,102 ± 216, before giving out the sternocleidomastoid muscular branches. The number of motor nerve fibers in the phrenic nerve was 911 ± 321~1,338 ± 467. The accessory nerve and the phrenic were similar in width, thickness and the number of motor nerve fibers. And

Facial nerve conduction after sclerotherapy in children with facial lymphatic malformations: report of two cases.

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Lin, Pei-Jung; Guo, Yuh-Cherng; Lin, Jan-You; Chang, Yu-Tang

2007-04-01

Surgical excision is thought to be the standard treatment of choice for lymphatic malformations. However, when the lesions are limited to the face only, surgical scar and facial nerve injury may impair cosmetics and facial expression. Sclerotherapy, an injection of a sclerosing agent directly through the skin into a lesion, is an alternative method. By evaluating facial nerve conduction, we observed the long-term effect of facial lymphatic malformations after intralesional injection of OK-432 and correlated the findings with anatomic outcomes. One 12-year-old boy with a lesion over the right-side preauricular area adjacent to the main trunk of facial nerve and the other 5-year-old boy with a lesion in the left-sided cheek involving the buccinator muscle were enrolled. The follow-up data of more than one year, including clinical appearance, computed tomography (CT) scan and facial nerve evaluation were collected. The facial nerve conduction study was normal in both cases. Blink reflex in both children revealed normal results as well. Complete resolution was noted on outward appearance and CT scan. The neurophysiologic data were compatible with good anatomic and functional outcomes. Our report suggests that the inflammatory reaction of OK-432 did not interfere with adjacent facial nerve conduction.

Somatic modulation of spinal reflex bladder activity mediated by nociceptive bladder afferent nerve fibers in cats.

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Xiao, Zhiying; Rogers, Marc J; Shen, Bing; Wang, Jicheng; Schwen, Zeyad; Roppolo, James R; de Groat, William C; Tai, Changfeng

2014-09-15

The goal of the present study was to determine if supraspinal pathways are necessary for inhibition of bladder reflex activity induced by activation of somatic afferents in the pudendal or tibial nerve. Cats anesthetized with α-chloralose were studied after acute spinal cord transection at the thoracic T9/T10 level. Dilute (0.25%) acetic acid was used to irritate the bladder, activate nociceptive afferent C-fibers, and trigger spinal reflex bladder contractions (amplitude: 19.3 ± 2.9 cmH2O). Hexamethonium (a ganglionic blocker, intravenously) significantly (P reflex bladder contractions to 8.5 ± 1.9 cmH2O. Injection of lidocaine (2%, 1-2 ml) into the sacral spinal cord or transection of the sacral spinal roots and spinal cord further reduced the contraction amplitude to 4.2 ± 1.3 cmH2O. Pudendal nerve stimulation (PNS) at frequencies of 0.5-5 Hz and 40 Hz but not at 10-20 Hz inhibited reflex bladder contractions, whereas tibial nerve stimulation (TNS) failed to inhibit bladder contractions at all tested frequencies (0.5-40 Hz). These results indicate that PNS inhibition of nociceptive afferent C-fiber-mediated spinal reflex bladder contractions can occur at the spinal level in the absence of supraspinal pathways, but TNS inhibition requires supraspinal pathways. In addition, this study shows, for the first time, that after acute spinal cord transection reflex bladder contractions can be triggered by activating nociceptive bladder afferent C-fibers using acetic acid irritation. Understanding the sites of action for PNS or TNS inhibition is important for the clinical application of pudendal or tibial neuromodulation to treat bladder dysfunctions. Copyright © 2014 the American Physiological Society.

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

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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.

Chronic cuffing of cervical vagus nerve inhibits efferent fiber integrity in rat model

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Somann, Jesse P.; Albors, Gabriel O.; Neihouser, Kaitlyn V.; Lu, Kun-Han; Liu, Zhongming; Ward, Matthew P.; Durkes, Abigail; Robinson, J. Paul; Powley, Terry L.; Irazoqui, Pedro P.

2018-06-01

Objective. Numerous studies of vagal nerve stimulation (VNS) have been published showing it to be a potential treatment for chronic inflammation and other related diseases and disorders. Studies in recent years have shown that electrical stimulation of the vagal efferent fibers can artificially modulate cytokine levels and reduce systematic inflammation. Most VNS research in the treatment of inflammation have been acute studies on rodent subjects. Our study tested VNS on freely moving animals by stimulating and recording from the cervical vagus with nerve cuff electrodes over an extended period of time. Approach. We used methods of electrical stimulation, retrograde tracing (using Fluorogold) and post necropsy histological analysis of nerve tissue, flow cytometry to measure plasma cytokine levels, and MRI scanning of gastric emptying. This novel combination of methods allowed examination of physiological aspects of VNS previously unexplored. Main results. Through our study of 53 rat subjects, we found that chronically cuffing the left cervical vagus nerve suppressed efferent Fluorogold transport in 43 of 44 animals (36 showed complete suppression). Measured cytokine levels and gastric emptying rates concurrently showed nominal differences between chronically cuffed rats and those tested with similar acute methods. Meanwhile, results of electrophysiological and histological tests of the cuffed nerves revealed them to be otherwise healthy, consistent with previous literature. Significance. We hypothesize that due to these unforeseen and unexplored physiological consequences of the chronically cuffed vagus nerve in a rat, that inflammatory modulation and other vagal effects by VNS may become unreliable in chronic studies. Given our findings, we submit that it would benefit the VNS community to re-examine methods used in previous literature to verify the efficacy of the rat model for chronic VNS studies.

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

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Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Arakawa, Naoko; Oshima, Susumu; Shibata, Naohisa; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

2012-01-01

To conduct high-resolution imaging of the retinal nerve fiber layer (RNFL) in normal eyes using adaptive optics scanning laser ophthalmoscopy (AO-SLO). 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. 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 (Poptical coherence tomography correlated with the hyperreflective bundle widths on AO-SLO (Pfiber 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.

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

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

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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.

An Exceptional Case of Intraparotid Plexiform Neurofibroma Originating from Autonomic Fibers of the Auriculotemporal Nerve

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Sarantis Blioskas

2017-01-01

Full Text Available Plexiform neurofibromas are benign tumors that tend to occur in patients suffering from neurofibromatosis type 1 (NF-1. This report addresses a rare case where the tumor affected the parotid gland, deriving almost exclusively from the peripheral portion of the facial nerve. A 6-year-old male was referred to us complaining about a gradually enlarging swelling over the right parotid area. Imaging localized the lesion to the superficial lobe of the parotid gland, suggesting a neurofibroma. Cosmetic disfigurement and a functional deficit led us to perform complete surgical resection. Meticulous surgical dissection as well as auriculotemporal nerve origin made complete extirpation possible with almost zero morbidity and ensured alleviation of both aesthetic impairment and pain. This is the first case of an intraparotid PN in a pediatric NF-1 patient, which originated from branches of the auriculotemporal nerve and particularly from fibers of the autonomic nervous system. Radical surgical excision was decided according to established decision-making algorithms.

The Effects of Smoking on Anterior Segment Parameters, Retinal Nerve Fiber Layer, and Pupillary Functions

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Bengü Ekinci Köktekir

2014-01-01

Full Text Available Objectives: To evaluate the alterations in the anterior segment parameters, retinal nerve fiber layer, and pupillary functions in smokers. Materials and Methods: In this case-control study, 45 eyes of 45 smokers and 45 eyes of 45 non-smoker control subjects were evaluated. All patients underwent measurement of anterior segment parameters with optical low coherence reflectometry (OLCR, mesopic and photopic pupillary diameter with an aberrometer device, retinal nerve fiber layer thickness with optical coherence tomography, and dry-eye assessment with Schirmer’s test. The results were compared with independent t-test by SPSS 16.0 Inc., and a p-value lower than 0.05 was determined as significant. Results: There was a significant difference between both groups in terms of mesopic pupil diameters that were measured with both OLCR and aberrometer device (p=0.03 and 0.02, respectively. Schirmer scores were also significantly decreased in smokers (p=0.001. The other measured parameters demonstrated no difference between smokers and non-smokers (p>0.05 for all. Conclusion: Smoking may affect pupillary functions, especially the mesopic pupillary diameter, and may cause a deficiency in pupil response under dark circumstances. (Turk J Ophthalmol 2014; 44: 11-4

Retinal Nerve Fiber Layer Segmentation on FD-OCT Scans of Normal Subjects and Glaucoma Patients.

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Mayer, Markus A; Hornegger, Joachim; Mardin, Christian Y; Tornow, Ralf P

2010-11-08

Automated measurements of the retinal nerve fiber layer thickness on circular OCT B-Scans provide physicians additional parameters for glaucoma diagnosis. We propose a novel retinal nerve fiber layer segmentation algorithm for frequency domain data that can be applied on scans from both normal healthy subjects, as well as glaucoma patients, using the same set of parameters. In addition, the algorithm remains almost unaffected by image quality. The main part of the segmentation process is based on the minimization of an energy function consisting of gradient and local smoothing terms. A quantitative evaluation comparing the automated segmentation results to manually corrected segmentations from three reviewers is performed. A total of 72 scans from glaucoma patients and 132 scans from normal subjects, all from different persons, composed the database for the evaluation of the segmentation algorithm. A mean absolute error per A-Scan of 2.9 µm was achieved on glaucomatous eyes, and 3.6 µm on healthy eyes. The mean absolute segmentation error over all A-Scans lies below 10 µm on 95.1% of the images. Thus our approach provides a reliable tool for extracting diagnostic relevant parameters from OCT B-Scans for glaucoma diagnosis.

Fiber/matrix interfacial thermal conductance effect on the thermal conductivity of SiC/SiC composites

International Nuclear Information System (INIS)

Nguyen, Ba Nghiep; Henager, Charles H.

2013-01-01

SiC/SiC composites used in fusion reactor applications are subjected to high heat fluxes and require knowledge and tailoring of their in-service thermal conductivity. Accurately predicting the thermal conductivity of SiC/SiC composites as a function of temperature will guide the design of these materials for their intended use, which will eventually include the effects of 14-MeV neutron irradiations. This paper applies an Eshelby–Mori–Tanaka approach (EMTA) to compute the thermal conductivity of unirradiated SiC/SiC composites. The homogenization procedure includes three steps. In the first step EMTA computes the homogenized thermal conductivity of the unidirectional (UD) SiC fiber embraced by its coating layer. The second step computes the thermal conductivity of the UD composite formed by the equivalent SiC fibers embedded in a SiC matrix, and finally the thermal conductivity of the as-formed SiC/SiC composite is obtained by averaging the solution for the UD composite over all possible fiber orientations using the second-order fiber orientation tensor. The EMTA predictions for the transverse thermal conductivity of several types of SiC/SiC composites with different fiber types and interfaces are compared to the predicted and experimental results by Youngblood et al. [J. Nucl. Mater. 307–311 (2002) 1120–1125, Fusion Sci. Technol. 45 (2004) 583–591, Compos. Sci. Technol. 62 (2002) 1127–1139.

Local delivery of glial cell line-derived neurotrophic factor improves facial nerve regeneration after late repair.

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Barras, Florian M; Kuntzer, Thierry; Zurn, Anne D; Pasche, Philippe

2009-05-01

Facial nerve regeneration is limited in some clinical situations: in long grafts, by aged patients, and when the delay between nerve lesion and repair is prolonged. This deficient regeneration is due to the limited number of regenerating nerve fibers, their immaturity and the unresponsiveness of Schwann cells after a long period of denervation. This study proposes to apply glial cell line-derived neurotrophic factor (GDNF) on facial nerve grafts via nerve guidance channels to improve the regeneration. Two situations were evaluated: immediate and delayed grafts (repair 7 months after the lesion). Each group contained three subgroups: a) graft without channel, b) graft with a channel without neurotrophic factor; and c) graft with a GDNF-releasing channel. A functional analysis was performed with clinical observation of facial nerve function, and nerve conduction study at 6 weeks. Histological analysis was performed with the count of number of myelinated fibers within the graft, and distally to the graft. Central evaluation was assessed with Fluoro-Ruby retrograde labeling and Nissl staining. This study showed that GDNF allowed an increase in the number and the maturation of nerve fibers, as well as the number of retrogradely labeled neurons in delayed anastomoses. On the contrary, after immediate repair, the regenerated nerves in the presence of GDNF showed inferior results compared to the other groups. GDNF is a potent neurotrophic factor to improve facial nerve regeneration in grafts performed several months after the nerve lesion. However, GDNF should not be used for immediate repair, as it possibly inhibits the nerve regeneration.

Fabrication of highly conductive carbon nanotube fibers for electrical application

International Nuclear Information System (INIS)

Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

2015-01-01

Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 10 6 s m −1 . The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers. (paper)

Highly stretchable and conductive fibers enabled by liquid metal dip-coating

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Zhang, Qiang; Roach, Devin J.; Geng, Luchao; Chen, Haosen; Qi, H. Jerry; Fang, Daining

2018-03-01

Highly stretchable and conductive fibers have been fabricated by dip-coating of a layer of liquid metal (eutectic gallium indium, EGaIn) on printed silicone elastomer filaments. This fabrication method exploits a nanolayer of oxide skin that rapidly forms on the surface of EGaIn when exposed to air. Through dip-coating, the sticky nature of the oxide skin leads to the formation of a thin EGaIn coating (˜5 μm thick) on the originally nonconductive filaments and renders these fibers excellent conductivity. Electrical characterization shows that the fiber resistance increases moderately as the fiber elongates but always maintains conductivity even when stretched by 800%. Besides this, these fibers possess good cyclic electrical stability with little degradation after hundreds of stretching cycles, which makes them an excellent candidate for stretchable conductors. We then demonstrate a highly stretchable LED circuit as well as a conductive stretchable net that extends the 1D fibers into a 2D configuration. These examples demonstrate potential applications for topologically complex stretchable electronics.

Prolonged phone-call posture causes changes of ulnar motor nerve conduction across elbow.

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Padua, Luca; Coraci, Daniele; Erra, Carmen; Doneddu, Pietro Emiliano; Granata, Giuseppe; Rossini, Paolo Maria

2016-08-01

Postures and work-hobby activities may play a role in the origin and progression of ulnar neuropathy at the elbow (UNE), whose occurrence appears to be increasing. The time spent on mobile-phone has increased in the last decades leading to an increased time spent with flexed elbow (prolonged-phone-posture, PPP). We aimed to assess the effect of PPP both in patients with symptoms of UNE and in symptom-free subjects. Patients with pure sensory symptoms of UNE and negative neurophysiological tests (MIN-UNE) and symptom-free subjects were enrolled. We evaluated ulnar motor nerve conduction velocity across elbow at baseline and after 6, 9, 12, 15, and 18min of PPP in both groups. Fifty-six symptom-free subjects and fifty-eight patients were enrolled. Globally 186 ulnar nerves from 114 subjects were studied. Conduction velocity of ulnar nerve across the elbow significantly changed over PPP time in patients with MIN-UNE, showing a different evolution between the two groups. PPP causes a modification of ulnar nerve functionality in patients with MIN-UNE. PPP may cause transient stress of ulnar nerve at elbow. Copyright © 2016 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Experimental study of effective thermal conductivity of stainless steel fiber felt

International Nuclear Information System (INIS)

Li, W.Q.; Qu, Z.G.

2015-01-01

An experimental apparatus was designed to measure the effective thermal conductivity of porous stainless steel fiber felt under different operating pressures. The total effective thermal conductivity was studied by analyzing matrix heat conduction, air natural convection, and matrix thermal radiation at ambient pressure. The contribution of air natural convection was experimentally obtained by changing the ambient pressure to vacuum condition and the solid matrix heat conduction was evaluated using a theoretical model. The ratios of the three mechanisms to the total effective thermal conductivity were approximately 40%, 37.9%, and 22.1%, respectively. In addition, the effects of fiber diameter and porosity on the three mechanisms and on the total effective thermal conductivity were studied. The air natural convection was found to gradually intensify when the operating pressure increases from vacuum condition (15 Pa) to ambient pressure (1.0 × 10 5  Pa). With an increase in fiber diameter under fixed porosity, the solid matrix heat conduction remained unchanged, and air natural convection and thermal radiation decreased, thereby resulting in reduced effective thermal conductivity. With an increase in porosity under fixed fiber diameter, the air natural convection was almost unchanged, and solid matrix heat conduction and thermal radiation were reduced, thereby resulting in reduced effective thermal conductivity. - Highlights: • Matrix conduction, radiation and air convection were in the same order of magnitude. • Air natural convection was suppressed by reducing operating pressure. • Intensity of air convection was more sensitive to fiber diameter than porosity. • Surface area and permeability was comparable in air convection as fiber diameter fixed. • Interfacial area exerted dominant role in radiation and air convection as porosity fixed

Investigations on Thermal Conductivities of Jute and Banana Fiber Reinforced Epoxy Composites

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Pujari, Satish; Ramakrishna, Avasarala; Balaram Padal, Korabu Tulasi

2017-04-01

The Jute and Banana fibers are used as reinforcement in epoxy resin matrix for making partially green biodegradable material composite via hand lay-up technique. The thermal conductivity of the jute fiber epoxy composites and banana fiber epoxy composites at different volume fraction of the fiber is determined experimentally by using guarded heat flow meter method. The experimental results had shown that thermal conductivity of the composites decrease with an increase in the fiber content. Experimental results are compared with theoretical models (Series model, Hashin model and Maxwell model) to describe the variation of the thermal conductivity versus the volume fraction of the fiber. Good agreement between theoretical and experimental results is observed. Thermal conductivity of Banana fiber composite is less when compared to that of Jute composite which indicates banana is a good insulator and also the developed composites can be used as insulating materials in building, automotive industry and in steam pipes to save energy by reducing rate of heat transfer.

[The role of 2,3-DPG in nerve conduction of children with type 1 diabetes].

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Pańkowska, Ewa; Szypowska, Agnieszka; Wysocka, Marta; Lipka, Maria

2005-01-01

Neuropathy is one of the chronic complications of diabetes, and it is uncommon in children and adolescents. It can be recognized in a short period after the onset of diabetes and not always is connected with poor metabolic control. Hypoxia is considered as one from greatest factors diabetic neuropathy and oxygen transport to tissue partially depends on the diphosphoglycerate (2,3 DPG) concentration. As showed recent clinical studies, its concentration in children with diabetes can be abnormal. To assess the role of 2,3 DPG in nerve conduction velocity, as well as qualification of risk factors. To study were included randomly selected 37 patients with diabetes type 1, average age 15.5+/-2.25 years, with a duration of diabetes of more than 5 years (av 9.64+/-1.95 years), treated with intensive insulin therapy (MDI and CSII), without metabolic acidosis pH - 7.35. The nerve conduction velocity was measured in the sensor and motor nerves. HbA1c and 2,3 DPG were assessed additionally. Changes in motor nerve conduction velocity were observed at 22 patients. Average value of HbA1c in the studied group was 8.22+/-1.2%, Average concentration of 2,3 DPG was 6.15+/-1.67 mmol/l (3.84-11 mmol/l), in group with nerve dysfunction was lower - 5.86+/-1.69 mmol/l vs. 6.38+/-1.67, but this difference was not statistically significant. The lower value of 2,3 DPG significantly correlated with abnormal results of electroneurography test, especially with motor and sensor nerve latency (r=-0.34, p=0.038; r=-0.4, p=0.013) but not correlated with HbA1c (r= -0,19;p= 0,25), age of patients (r=0.008; p=0.96) and diabetes duration (r=-0.16; p=0.31). Nerve dysfunction is common in children with type 1 diabetes despite metabolic control and duration of diabetes. 2,3 DPG can be an independent factor of diabetes neuropathy correlated with abnormal value of the nerve conduction test.

Sciatic nerve regeneration in rats by a promising electrospun collagen/poly(ε-caprolactone nerve conduit with tailored degradation rate

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Jiang Xinquan

2011-07-01

Full Text Available Abstract Background To cope with the limitations faced by autograft acquisitions particularly for multiple nerve injuries, artificial nerve conduit has been introduced by researchers as a substitute for autologous nerve graft for the easy specification and availability for mass production. In order to best mimic the structures and components of autologous nerve, great efforts have been made to improve the designation of nerve conduits either from materials or fabrication techniques. Electrospinning is an easy and versatile technique that has recently been used to fabricate fibrous tissue-engineered scaffolds which have great similarity to the extracellular matrix on fiber structure. Results In this study we fabricated a collagen/poly(ε-caprolactone (collagen/PCL fibrous scaffold by electrospinning and explored its application as nerve guide substrate or conduit in vitro and in vivo. Material characterizations showed this electrospun composite material which was made of submicron fibers possessed good hydrophilicity and flexibility. In vitro study indicated electrospun collagen/PCL fibrous meshes promoted Schwann cell adhesion, elongation and proliferation. In vivo test showed electrospun collagen/PCL porous nerve conduits successfully supported nerve regeneration through an 8 mm sciatic nerve gap in adult rats, achieving similar electrophysiological and muscle reinnervation results as autografts. Although regenerated nerve fibers were still in a pre-mature stage 4 months postoperatively, the implanted collagen/PCL nerve conduits facilitated more axons regenerating through the conduit lumen and gradually degraded which well matched the nerve regeneration rate. Conclusions All the results demonstrated this collagen/PCL nerve conduit with tailored degradation rate fabricated by electrospinning could be an efficient alternative to autograft for peripheral nerve regeneration research. Due to its advantage of high surface area for cell attachment, it

[Morphology research of the rat sciatic nerve bridged by collage-heparin sulfate scaffold].

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Wang, Shu-sen; Hu, Yun-yu; Luo, Zhuo-jing; Chen, Liang-wei; Liu, Hui-ling; Meng, Guo-lin; Lü, Rong; Xu, Xin-zhi

2005-04-15

To observe the treating effect of collage-heparin sulfate after the 10 mm rat sciatic nerve defect was bridged by it. A new kind of nervous tissue engineering scaffold was produced by freeze-drying technique from collagen-heparin sulfate. Thirty-two SD rats were randomly divided into A, B, C and D groups. Sciatic nerve defect in group A was bridged by collagen-heparin sulfate. In group B, sciatic nerve was bridged by auto-nerve transplantation. Group C was the blank control group. Animals in group D were normal. And 10 mm sciatic nerve defect was bridged in the experiment. Thirty-six weeks after the operation, the experimental animals were detected by HRP labeled retrograde trace, HE staining, toluidine staining, silvering staining, S100, GAP-43 and NF immunohistological staining, MBP immunofluorescence staining and transmission electron microscope to observe the nerve regeneration inducing effect of this new scaffold. Nine months after operation, the collage-heparin sulfate scaffold was replaced by newly regenerated nerve. The number of HRP labeled spinal cord anterior horn cells and the area of sensation nerve fiber at the posterior horn were similar with that was repaired by auto-nerve. GAP-43, NF and S100 labeled regenerated nerve fiber had passed the total scaffold and entered the distal terminal. The regenerated nerve fibers were paralleled, lineage arranged, coincide with the prearranged regenerating "channel" in the collagen-heparin sulfate scaffold. MBP immunofluorescence staining also proved that the newly regenerated nerve fiber could be ensheathed. In the experimental group, the area of myelinated nerve fiber and the thickness of the myelin sheath had no obvious difference with that of the group repaired by auto-nerve, except that the density of the regenerated myelinated sheath fiber was lower than that of the control group. Nervous tissue engineering scaffold produced by collagen-heparin sulfate can guide the regeneration of nerve fibers. The nerve

Adipose-derived mesenchymal stem cells accelerate nerve regeneration and functional recovery in a rat model of recurrent laryngeal nerve injury

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Yun Li

2017-01-01

Full Text Available Medialization thyroplasty or injection laryngoplasty for unilateral vocal fold paralysis cannot restore mobility of the vocal fold. Recent studies have shown that transplantation of mesenchymal stem cells is effective in the repair of nerve injuries. This study investigated whether adipose-derived stem cell transplantation could repair recurrent laryngeal nerve injury. Rat models of recurrent laryngeal nerve injury were established by crushing with micro forceps. Adipose-derived mesenchymal stem cells (ADSCs; 8 × 105 or differentiated Schwann-like adipose-derived mesenchymal stem cells (dADSCs; 8 × 105 or extracellular matrix were injected at the site of injury. At 2, 4 and 6 weeks post-surgery, a higher density of myelinated nerve fiber, thicker myelin sheath, improved vocal fold movement, better recovery of nerve conduction capacity and reduced thyroarytenoid muscle atrophy were found in ADSCs and dADSCs groups compared with the extracellular matrix group. The effects were more pronounced in the ADSCs group than in the dADSCs group. These experimental results indicated that ADSCs transplantation could be an early interventional strategy to promote regeneration after recurrent laryngeal nerve injury.

The morphological substrate for Renal Denervation: Nerve distribution patterns and parasympathetic nerves. A post-mortem histological study.

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van Amsterdam, Wouter A C; Blankestijn, Peter J; Goldschmeding, Roel; Bleys, Ronald L A W

2016-03-01

Renal Denervation as a possible treatment for hypertension has been studied extensively, but knowledge on the distribution of nerves surrounding the renal artery is still incomplete. While sympathetic and sensory nerves have been demonstrated, there is no mention of the presence of parasympathetic nerve fibers. To provide a description of the distribution patterns of the renal nerves in man, and, in addition, provide a detailed representation of the relative contribution of the sympathetic, parasympathetic and afferent divisions of the autonomic nervous system. Renal arteries of human cadavers were each divided into four longitudinal segments and immunohistochemically stained with specific markers for afferent, parasympathetic and sympathetic nerves. Nerve fibers were semi-automatically quantified by computerized image analysis, and expressed as cross-sectional area relative to the distance to the lumen. A total of 3372 nerve segments were identified in 8 arteries of 7 cadavers. Sympathetic, parasympathetic and afferent nerves contributed for 73.5% (95% CI: 65.4-81.5%), 17.9% (10.7-25.1%) and 8.7% (5.0-12.3%) of the total cross-sectional nerve area, respectively. Nerves are closer to the lumen in more distal segments and larger bundles that presumably innervate the kidney lie at 1-3.5mm distance from the lumen. The tissue-penetration depth of the ablation required to destroy 50% of the nerve fibers is 2.37 mm in the proximal segment and 1.78 mm in the most distal segments. Sympathetic, parasympathetic and afferent nerves exist in the vicinity of the renal artery. The results warrant further investigation of the role of the parasympathetic nervous system on renal physiology, and may contribute to refinement of the procedure by focusing the ablation on the most distal segment. Copyright © 2015 Elsevier GmbH. All rights reserved.

Preparation of ZnO nanorods on conductive PET-ITO-Ag fibers

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Li, Yiwen; Ji, Shuai; Chen, Yuanyu; Zhang, Hong; Gong, Yumei; Guo, Jing

2016-12-01

We studied the vertical ZnO nanorods grown on conductive conventional polyethylene terephthalate (PET) fibers which are prepared by electroless silver depositing on tin-doped indium oxide (ITO) coated PET fibers through an efficient and low-cost green approach. The PET fibers were firstly functionalized with a layer of ITO gel synthesized through a sol-gel process at rather low temperature, simply by immersing the fibers into ITO sol for several minutes followed by gelation at 120 °C. Once the ITO gel layer surface was activated by SnCl2, a continuous, uniform, and compact layer of silver was carried out on the surface of the PET-ITO fibers through electroless plating operation at room temperature. The as-prepared PET-ITO-Ag fibers had good electrical conductivity, with surface resistivity as low as 0.23 mΩ cm. The overall procedure is simple, efficient, nontoxic, and controllable. The conductive PET-ITO-Ag fiber was used successfully as a flexible basal material to plant vertical ZnO nanorods through controlling the seeding and growth processes. The morphology of the PET-ITO, PET-ITO-Ag, and PET-ITO-Ag-ZnO fibers were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Undergone the whole process, although the tensile strength of the fiber decreased slightly, they may still exert their applications in flexible electronic such as photovoltaic and piezoelectric devices.

Age-related ultrastructural and monoamine oxidase changes in the rat optic nerve.

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Taurone, S; Ripandelli, G; Minni, A; Lattanzi, R; Miglietta, S; Pepe, N; Fumagalli, L; Micera, A; Pastore, F S; Artico, M

2016-01-01

The aim of this paper is to study the morphology and the distribution of the monoamine oxidase enzymatic system in the optic nerve of 4 month-old Wistar (young) and 28 month-old Wistar (old) rats. The optic nerve was harvested from 20 young and old rats. The segment of optic nerve was divided longitudinally into two pieces, each 0.1 mm in length. The first piece was used for transmission electron microscopy. The second piece was stained with histochemical reaction for monoamine oxidase. The agerelated changes in the optic nerve of rats include micro-anatomical details, ultrastructure and monoamine oxidase histochemical staining. A strong decrease of the thin nerve fibers and a swelling of the thick ones can be observed in optic nerve fibers of old rats. Increased monoamine oxidase histochemical staining of the optic nerve of aged rats is well demonstrated. The increase of meningeal shealth and the decrease of thin nerve fibers of the optic nerve in old rats are well documented. Morphological, ultrastructural and histochemical changes observed in optic nerve fibers of the old rats show a close relation with aging.

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.

Effects of capsaicin in the motor nerve.

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Pettorossi, V E; Bortolami, R; Della Torre, G; Brunetti, O

1994-08-01

The injection of capsaicin into the lateral gastrocnemius (LG) muscle of the rat induced an immediate and sustained reduction in the A delta and C components of the compound action potential (CAP) of the LG motor nerve. Conversely, the drug did not immediately affect the CAP wave belonging to fast-conducting fibers or the motor responses to LG nerve stimulation. It seems that capsaicin only affects the group III and IV afferents of LG nerve. However, a week after the injection the capsaicin also altered the motor responses, as shown by the threshold enhancement and amplitude reduction of the muscle twitch and by the decrease of the A alpha-beta CAP components. This late motor impairment was attributed to a central depression following a reduction of capsaicin-sensitive neuron input into the CNS. However, this motor effect was transient since the LG nerve regained the preinjection excitability level in a week and the muscle twitch amplitude reached the control value in a month.

Phrenic Nerve Conduction Study in the Early Stage of Guillain-Barre Syndrome as a Predictor of Respiratory Failure.

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Sen, Barun Kumar; Pandit, Alak

2018-01-01

Guillain-Barré syndrome (GBS) has unpredictable clinical course with severe complication of respiratory failure. To identify clinical profiles and electrophysiological study particularly non-invasive Phrenic nerve conduction study in patients of early GBS to predict respiratory failure. 64 adult (age≥18yrs) patients of early GBS (onset ≤ 14 days) during the study period from January 2014 to October 2015 were evaluated by clinical profiles of age, gender, antecedent infection, time to peak disability, single breath counts, cranial nerve involvement, autonomic dysfunction and non-invasive Phrenic nerve conduction study. Patients with predisposition factors of polyneuropathy like diabetes mellitus, hypothyroidism, vitamin deficiency, renal failure were excluded. Among 64 patients abnormal phrenic nerve conduction study was seen in 65.62% cases (42/64) and 45.23% (19/42) of them developed respiratory failure. Phrenic nerve sum latency, amplitude, duration and area were abnormal in those who developed respiratory failure and they had sum of phrenic nerve latency >28 msec, sum of CMAP amplitude 50 msec and sum of area phrenic nerve study developed respiratory failure. It was found that age, gender, preceding infection, autonomic involvement and types of GB syndrome had no influence on development of respiratory failure (p>0.05). Rapid disease progression to peak disability, more severe disease, shorter single breath counts and cranial nerve involvement were seen more often in patients with respiratory failure. Abnormal Phrenic nerve conduction study in the early Guillain-Barré syndrome might be of great value independently in predicting impending respiratory failure.

Phrenic Nerve Conduction Study in the Early Stage of Guillain–Barre Syndrome as a Predictor of Respiratory Failure

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Sen, Barun Kumar; Pandit, Alak

2018-01-01

Background: Guillain-Barré syndrome (GBS) has unpredictable clinical course with severe complication of respiratory failure. Objective: To identify clinical profiles and electrophysiological study particularly non-invasive Phrenic nerve conduction study in patients of early GBS to predict respiratory failure. Methods: 64 adult (age≥18yrs) patients of early GBS (onset ≤ 14 days) during the study period from January 2014 to October 2015 were evaluated by clinical profiles of age, gender, antecedent infection, time to peak disability, single breath counts, cranial nerve involvement, autonomic dysfunction and non-invasive Phrenic nerve conduction study. Patients with predisposition factors of polyneuropathy like diabetes mellitus, hypothyroidism, vitamin deficiency, renal failure were excluded. Results: Among 64 patients abnormal phrenic nerve conduction study was seen in 65.62% cases (42/64) and 45.23% (19/42) of them developed respiratory failure. Phrenic nerve sum latency, amplitude, duration and area were abnormal in those who developed respiratory failure and they had sum of phrenic nerve latency >28 msec, sum of CMAP amplitude 50 msec and sum of area phrenic nerve study developed respiratory failure. It was found that age, gender, preceding infection, autonomic involvement and types of GB syndrome had no influence on development of respiratory failure (p>0.05). Rapid disease progression to peak disability, more severe disease, shorter single breath counts and cranial nerve involvement were seen more often in patients with respiratory failure. Conclusion: Abnormal Phrenic nerve conduction study in the early Guillain-Barré syndrome might be of great value independently in predicting impending respiratory failure. PMID:29720799

Findings of Optical Coherence Tomography of Retinal Nerve Fiber Layer in Two Common Types of Multiple Sclerosis

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Gholamali Yousefipour

2016-06-01

Full Text Available Multiple sclerosis (MS is the most prevalent disease caused by the inflammatory demyelinating process that causes progressive nervous system degeneration over the time. Optical Coherence Tomography (OCT is a non-invasive optical imaging technology, which can measure the thickness of retinal nerve fiber layer as well as the diameter of the macula. The purpose of the study is evaluation OCT findings in two common types of multiple sclerosis. For doing the cross-sectional study, 63 patients with two prevalent types of multiple sclerosis (35 patients with Relapse Remitting Multiple Sclerosis (RRMS and 28 patients with Secondary Progressive Multiple Sclerosis (SPMS were evaluated for 6 months. Exclusion criteria of the study were a history of optic neuritis, suffering from diabetes mellitus, hypertension, ocular disease, and the presence of other neurologic degenerative diseases. Then, the thickness of retinal nerve fiber layer (RNFL, as well as thickness and volume of the macula, were measured in the patients using OCT technology. The disability rate of patients was evaluated according to Expanded Disability Status Scale (EDSS. Finally, data was analyzed by means of SPSS software. Overall, 35 patients with RRMS (with mean age of 32.37+10.01, average disease period of 3.81+3.42 and mean EDSS of 1.84+0.45 and 28 patients with SPMS (with mean age of 39.21+9.33, average disease period of 11.32+5.87 and mean EDSS of 5.12+1.46 were assessed and compared in terms of retinal nerve fiber layer and size and thickness of macula. In all of these sections, the thicknesses were smaller in SPMS patients than patients with RRMS. But, there was a significant difference in total thickness (81.82µm versus 96.03µm with P=0.04 and thickness of temporal sector (54.5 µm versus 69.34 µm with P=0.04 of retinal nerve fiber layer and macular size at the superior sector of external ring (1.48 mm³ versus 1.58 mm³ with P=0.03, and nasal sector of external ring surrounding

Gallic acid and exercise training improve motor function, nerve conduction velocity but not pain sense reflex after experimental sciatic nerve crush in male rats

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Maryam Hajimoradi

2015-06-01

Full Text Available Objective: The aim of present study was to evaluate the effects of oral administration of gallic acid (GA for 21 days alone and in combination with exercise on nerve conduction velocity and sensory and motor functions in rats with sciatic nerve crush. Materials and Methods: Seventy adult male Wistar rats (250-300 g were divided randomly into 7 groups with 10 in each: 1 Control (Cont, 2 Crushed + Vehicle (Cr +Veh, 3-5 Crushed + gallic acid (Cr+GA (50, 100, and 200 mg/kg/2 mL, orally, 6 Crushed + exercise (Cr+Exe, and 7 Crushed + exercise + effective dose of gallic acid (Cr+Exe +GA200 for 21 days. In order to establish an animal model of sciatic nerve crush, equivalent to 7 kg of force pressed on 2-3 mm of sciatic nerve for 30 s, three times with 30 s intervals. Pain sense reflex in hot plate, motor coordination in rotarod, and sciatic nerve conduction velocity (SNCV in all groups were tested. Data were analyzed using one-way ANOVA followed by Tukey’s post hoc test and pResults: Pain threshold was increased significantly in untreated crushed rats while motor function and SNCV were decreased in all groups with nerve crush (p

[Changes in facial nerve function, morphology and neurotrophic factor III expression following three types of facial nerve injury].

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Zhang, Lili; Wang, Haibo; Fan, Zhaomin; Han, Yuechen; Xu, Lei; Zhang, Haiyan

2011-01-01

To study the changes in facial nerve function, morphology and neurotrophic factor III (NT-3) expression following three types of facial nerve injury. Changes in facial nerve function (in terms of blink reflex (BF), vibrissae movement (VM) and position of nasal tip) were assessed in 45 rats in response to three types of facial nerve injury: partial section of the extratemporal segment (group one), partial section of the facial canal segment (group two) and complete transection of the facial canal segment lesion (group three). All facial nerves specimen were then cut into two parts at the site of the lesion after being taken from the lesion site on 1st, 7th, 21st post-surgery-days (PSD). Changes of morphology and NT-3 expression were evaluated using the improved trichrome stain and immunohistochemistry techniques ,respectively. Changes in facial nerve function: In group 1, all animals had no blink reflex (BF) and weak vibrissae movement (VM) at the 1st PSD; The blink reflex in 80% of the rats recovered partly and the vibrissae movement in 40% of the rats returned to normal at the 7th PSD; The facial nerve function in 600 of the rats was almost normal at the 21st PSD. In group 2, all left facial nerve paralyzed at the 1st PSD; The blink reflex partly recovered in 40% of the rats and the vibrissae movement was weak in 80% of the rats at the 7th PSD; 8000 of the rats'BF were almost normal and 40% of the rats' VM completely recovered at the 21st PSD. In group 3, The recovery couldn't happen at anytime. Changes in morphology: In group 1, the size of nerve fiber differed in facial canal segment and some of myelin sheath and axons degenerated at the 7th PSD; The fibres' degeneration turned into regeneration at the 21st PSD; In group 2, the morphologic changes in this group were familiar with the group 1 while the degenerated fibers were more and dispersed in transection at the 7th PSD; Regeneration of nerve fibers happened at the 21st PSD. In group 3, most of the fibers

Electromagnetic interference shielding effectiveness of polypropylene/conducting fiber composites

International Nuclear Information System (INIS)

Lee, Pyoung-Chan; Kim, Bo-Ram; Jeoung, Sun Kyoung; Kim, Yeung Keun

2016-01-01

Electromagnetic released from the automotive electronic parts is harmful to human body. Electromagnetic interference (EMT) shielding refers to the reflection and/or adsorption of electromagnetic radiation by a material, which thereby acts as a shield against the penetration of the radiation through the shield. Polypropylene (PP)/conductive micro fiber composites containing various fiber contents and fiber length were injection-molded. The effect of fiber content and length on electrical properties of the composites was studied by electrical resistivity and EMT shielding measurements. The through-plane electrical conductivity and dielectric permittivity were obtained by measuring dielectric properties. The EMT shielding effectiveness (SE) was investigated by using S-parameter in the range of 100 ~ 1500 MHz. Reflection, absorption and multiple-reflection are the EMT attenuation mechanisms. From the measurement of S-Parameters, the absorption coefficient, reflection coefficient, and the shielding efficiency of the materials were calculated. The EMT SE of PP/conducing fiber composites is 40 dB over a wide frequency range up to 1.5 GHz, which is higher than that of PP/talc composite used automotive parts, viz. 0 dB.

Análise quantitativa das fibras mielínicas dos nervos laríngeos em humanos de acordo com a idade Quantitative analysis of myelinic fibers in human laryngeal nerves according to age

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Romualdo Suzano Louzeiro Tiago

2008-02-01

Full Text Available INTRODUÇÃO E OBJETIVO: Realizar análise morfométrica das fibras mielínicas dos nervos laríngeos com a finalidade de verificar modificações quantitativas decorrentes do processo de envelhecimento. FORMA DE ESTUDO: Clínico e experimental. Material e Método: Foi coletado fragmento de 1cm dos nervos laríngeos superiores e nervos laríngeos recorrentes de 12 cadáveres do sexo masculino. A amostra foi dividida em dois grupos: idade inferior a 60 anos (Adulto e idade igual ou superior a 60 anos (Idoso. O material foi avaliado em microscópio de luz acoplado a sistema analisador de imagem. RESULTADOS: O número total de fibras mielínicas do nervo laríngeo superior foi semelhante nos dois grupos etários, mas com tendência para o maior número de fibras de 1µm no grupo adulto (p=0,0744. O grupo adulto apresentou maior número total de fibras mielínicas no nervo laríngeo recorrente (p=0,0006, e esta diferença ocorreu nas fibras com diâmetros de 1-3µm (pINTRODUCTION AND AIM: To carry out a morphometric analysis of myelinic fibers in laryngeal nerves aiming to identify quantitative changes as a result of aging. Study design: Clinical and experimental. MATERIAL AND METHOD: A 1cm fragment was collected from the superior laryngeal nerves and recurrent laryngeal nerves taken from twelve male cadavers. The sample was divided into two groups: those aged below 60 years (Adult and those aged 60 years or more (Elderly. The material was evaluated under light microscopy coupled with an image analysis system. RESULTS: The total number of myelinic fibers from the superior laryngeal nerve was similar in both age groups; there was, however, a trend for a higher number of 1μm fibers in the adult group (p=0.0744. The adult group had a higher total number of myelinic fibers in the recurrent laryngeal nerve (p=0.0006, and this difference was seen in fibers with diameters betwee 1-3μm (p<0.007. The adult group had a higher total number of myelinic fibers

Effect of fiber content on the thermal conductivity and dielectric constant of hair fiber reinforced epoxy composite

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Prasad Nanda, Bishnu; Satapathy, Alok

2018-03-01

This paper reports on the dielectric and thermal properties of hair fibers reinforced epoxy composites. Hair is an important part of human body which also offers protection to the human body. It is also viewed as a biological waste which is responsible for creating environmental pollution due to its low decomposition rate. But at the same time it has unique microstructural, mechanical and thermal properties. In the present work, epoxy composites are made by solution casting method with different proportions of short hair fiber (SHF). Effects of fiber content on the thermal conductivity and dielectric constant of epoxy resin are studied. Thermal conductivities of the composites are obtained using a UnithermTM Model 2022 tester. An HIOKI-3532-50 Hi Tester Elsier Analyzer is used for measuring the capacitance of the epoxy-SHF composite, from which dielectric constant (Dk) of the composite are calculated. A reduction in thermal conductivity of the composite is noticed with the increase in wt. % of fiber. The dielectric constant value of the composites also found to be significantly affected by the fiber content.

Significant correlations between optic nerve head microcirculation and visual field defects and nerve fiber layer loss in glaucoma patients with myopic glaucomatous disk

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Yokoyama Y

2011-12-01

Full Text Available Yu Yokoyama, Naoko Aizawa, Naoki Chiba, Kazuko Omodaka, Masahiko Nakamura, Takaaki Otomo, Shunji Yokokura, Nobuo Fuse, Toru NakazawaDepartment of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, JapanBackground: Eyes with glaucoma are characterized by optic neuropathy with visual field defects in the areas corresponding to the optic disk damage. The exact cause for the glaucomatous optic neuropathy has not been determined. Myopia has been shown to be a risk factor for glaucoma. The purpose of this study was to determine whether a significant correlation existed between the microcirculation of the optic disk and the visual field defects and the retinal nerve fiber layer thickness (RNFLT in glaucoma patients with myopic optic disks.Methods: Sixty eyes of 60 patients with myopic disks were studied; 36 eyes with glaucoma (men:women = 19:17 and 24 eyes with no ocular diseases (men:women = 14:10. The mean deviation (MD determined by the Humphrey field analyzer, and the peripapillary RNFLT determined by the Stratus-OCT were compared between the two groups. The ocular circulation was determined by laser speckle flowgraphy (LSFG, and the mean blur rate (MBR was compared between the two groups. The correlations between the RNFLT and MBR of the corresponding areas of the optic disk and between MD and MBR of the optic disk in the glaucoma group were determined by simple regression analyses.Results: The average MBR for the entire optic disk was significantly lower in the glaucoma group than that in the control group. The differences of the MBR for the tissue in the superior, inferior, and temporal quadrants of the optic disk between the two groups were significant. The MBR for the entire optic disk was significantly correlated with the MD (r = 0.58, P = 0.0002 and the average RNFLT (r = 0.53, P = 0.0008. The tissue MBR of the optic disk was significantly correlated with the RNFLT in the superior, inferior, and temporal quadrants

Long-term retinal nerve fiber layer changes following nonarteritic anterior ischemic optic neuropathy

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Dotan G

2013-04-01

Full Text Available Gad Dotan,1 Michaella Goldstein,1 Anat Kesler,1 Barry Skarf21Department of Ophthalmology, Tel Aviv Medical Center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel; 2Eye Care Services, Henry Ford Hospital, Detroit, MI, USABackground: In cases of nonarteritic anterior ischemic optic neuropathy (NAION, retinal nerve fiber layer (RNFL thickness changes have been described during the first 12 months following the acute event. The purpose of this study was to report on the long-term RNFL changes in these eyes beyond the first year following onset of NAION.Methods: Fourteen eyes of 13 patients with NAION were analyzed in this retrospective observational case series study. Uninvolved eyes served as controls. All patients underwent a complete neuro-ophthalmological examination and repeat measurements of peripapillary RNFL thickness using Stratus optical coherence tomography.Results: On optical coherence tomography scan performed on average 6 months following onset of NAION, the mean global RNFL thickness (59.8 ± 11.8 μm was significantly thinner (P < 0.001 compared with uninvolved eyes (95.1 ± 13.9 μm. In a second optical coherence tomography scan performed on average 13 (range 12–23 months later, the mean global RNFL thickness (58.9 ± 6.5 μm was not significantly different (P = 0.702 from the first scan.Conclusion: There appears to be no further RNFL loss beyond the first 6 months following an acute event of NAION.Keywords: optical coherence tomography, retinal nerve fiber layer, nonartertic anterior ischemic optic neuropathy

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

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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.

Effect of Surface Pore Structure of Nerve Guide Conduit on Peripheral Nerve Regeneration

Science.gov (United States)

Oh, Se Heang; Kim, Jin Rae; Kwon, Gu Birm; Namgung, Uk; Song, Kyu Sang

2013-01-01

Polycaprolactone (PCL)/Pluronic F127 nerve guide conduits (NGCs) with different surface pore structures (nano-porous inner surface vs. micro-porous inner surface) but similar physical and chemical properties were fabricated by rolling the opposite side of asymmetrically porous PCL/F127 membranes. The effect of the pore structure on peripheral nerve regeneration through the NGCs was investigated using a sciatic nerve defect model of rats. The nerve fibers and tissues were shown to have regenerated along the longitudinal direction through the NGC with a nano-porous inner surface (Nanopore NGC), while they grew toward the porous wall of the NGC with a micro-porous inner surface (Micropore NGC) and, thus, their growth was restricted when compared with the Nanopore NGC, as investigated by immunohistochemical evaluations (by fluorescence microscopy with anti-neurofilament staining and Hoechst staining for growth pattern of nerve fibers), histological evaluations (by light microscopy with Meyer's modified trichrome staining and Toluidine blue staining and transmission electron microscopy for the regeneration of axon and myelin sheath), and FluoroGold retrograde tracing (for reconnection between proximal and distal stumps). The effect of nerve growth factor (NGF) immobilized on the pore surfaces of the NGCs on nerve regeneration was not so significant when compared with NGCs not containing immobilized NGF. The NGC system with different surface pore structures but the same chemical/physical properties seems to be a good tool that is used for elucidating the surface pore effect of NGCs on nerve regeneration. PMID:22871377

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

OpenAIRE

Gencer, Baran; Cosar, Murat; Tufan, Hasan Ali; Kara, Selcuk; Arikan, Sedat; Akman, Tarik; Kiraz, Hasan Ali; Comez, Arzu Taskiran; Hanci, Volkan

2015-01-01

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. ...

Reversible conduction block in peripheral nerve using electrical waveforms.

Science.gov (United States)

Bhadra, Niloy; Vrabec, Tina L; Bhadra, Narendra; Kilgore, Kevin L

2018-01-01

Electrical nerve block uses electrical waveforms to block action potential propagation. Two key features that distinguish electrical nerve block from other nonelectrical means of nerve block: block occurs instantly, typically within 1 s; and block is fully and rapidly reversible (within seconds). Approaches for achieving electrical nerve block are reviewed, including kilohertz frequency alternating current and charge-balanced polarizing current. We conclude with a discussion of the future directions of electrical nerve block. Electrical nerve block is an emerging technique that has many significant advantages over other methods of nerve block. This field is still in its infancy, but a significant expansion in the clinical application of this technique is expected in the coming years.

Loss of temporal peripapillary retinal nerve fibers in prediabetes or type 2 diabetes without diabetic retinopathy: The Maastricht Study

NARCIS (Netherlands)

de Clerck, E.E.B.; Schouten, J.S.A.G.; Berendschot, T.T.J.M.; Beckers, H.J.M.; Schaper, N.C.; Schram, M.T.; Stehouwer, C.D.A.; Webers, C.A.B.

Purpose: The purpose of this study was to assess thinning of the peripapillary retinal nerve fiber layer (RNFL) in prediabetes or type 2 diabetes without diabetic retinopathy (DM2 w/o DRP) compared with that in individuals with normal glucose metabolism (NGM). Methods: We measured sectoral and mean

Highly-wrinkled reduced graphene oxide-conductive polymer fibers for flexible fiber-shaped and interdigital-designed supercapacitors

Science.gov (United States)

Li, Bo; Cheng, Jianli; Wang, Zhuanpei; Li, Yinchuan; Ni, Wei; Wang, Bin

2018-02-01

Flexible supercapacitors have attracted great interest due to outstanding flexibility and light weight. Poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) fibers have the great potential in using as electrodes for flexible supercapacitors due to the good flexibility. However, the reported conductivity and specific capacitance of these PEDOT: PSS fibers are not very high, which limit their electrochemical performances. In this work, composite fibers of reduced graphene oxide(rGO)-PEDOT: PSS with a highly-wrinkled structure on the surface and pores inside are prepared by wet spinning. The fibers with different ratios of graphene to PEDOT:PSS show a distinctly enhanced conductivity up to ca. 590 S·cm-1 and high strength up to ca. 18.4 MPa. Meanwhile, the composite fibers show an improved electrochemical performances, including a high specific areal capacitance of 131 mF cm-2 and high specific areal energy density of 4.55 μWh·cm-2. The flexible supercapacitors including fiber-shaped supercapacitors and interdigital designed supercapacitors not only could work in different bending states without obvious capacitance decay, but also have small leakage current. The interdigital design can further improve the performances of composite fibers with high capacitance and high utilization compared with traditional parallel connected structure.

Neurological Assessment and Nerve Conduction Study Findings in 22 Patients with Alkaptonuria from Jordan.

Science.gov (United States)

Alrawashdeh, Omar; Alsbou, Mohammad; Alzoubi, Hamed; Al-Shagahin, Hani

2016-11-02

Alkaptonuria is a rare metabolic disease characterised by accumulative deposition of homogentisic acid in the connective tissue of the body. This results in early degeneration of tendons, cartilages, heart valves, and other tissues. The main objective of the study is to examine the possibility of the nervous system involvement in patients with alkaptonuria The sample consists of two groups; 22 patients with AKU and 20 controls. A neurological assessment has been carried out including detailed medical history, neurological examination, and a nerve conduction study of the nerves of the dominant hand. The prevalence of any abnormality was compared between the two groups using chi square test. The mean values of the nerve conduction study were compared between the two groups using student t-test. There was a higher prevalence of low back pain, hearing problems and tinnitus, numbness and neuropathic pain in alkaptonuria patients. There was no significant difference between the two groups in other conditions such as seizures, headache, and syncope. The values of the nerve conduction study did not show significant difference between the two groups. Neurologically related symptoms in alkaptonuria mostly represent complications of the connective tissue degeneration rather than direct involvement of the nervous system. This has been supported further by the normal findings of the neurophysiology study in patients with alkaptonuria.

Neurological assessment and nerve conduction study findings in 22 patients with alkaptonuria from Jordan

Directory of Open Access Journals (Sweden)

Omar Alrawashdeh

2017-01-01

Full Text Available Alkaptonuria is a rare metabolic disease characterised by accumulative deposition of homogentisic acid in the connective tissue of the body. This results in early degeneration of tendons, cartilages, heart valves, and other tissues. The main objective of the study is to examine the possibility of the nervous system involvement in patients with alkaptonuria The sample consists of two groups; 22 patients with AKU and 20 controls. A neurological assessment has been carried out including detailed medical history, neurological examination, and a nerve conduction study of the nerves of the dominant hand. The prevalence of any abnormality was compared between the two groups using chi square test. The mean values of the nerve conduction study were compared between the two groups using student t-test. There was a higher prevalence of low back pain, hearing problems and tinnitus, numbness and neuropathic pain in alkaptonuria patients. There was no significant difference between the two groups in other conditions such as seizures, headache, and syncope. The values of the nerve conduction study did not show significant difference between the two groups. Neurologically related symptoms in alkaptonuria mostly represent complications of the connective tissue degeneration rather than direct involvement of the nervous system. This has been supported further by the normal findings of the neurophysiology study in patients with alkaptonuria.

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.

High thermal conductivity of graphite fiber silicon carbide composites for fusion reactor application

International Nuclear Information System (INIS)

Snead, L.L.; Balden, M.; Causey, R.A.; Atsumi, H.

2002-01-01

The benefits of using CVI SiC/graphite fiber composites as low tritium retaining, high thermal conductivity composites for fusion applications are presented. Three-dimensional woven composites have been chemically vapor infiltrated with SiC and their thermophysical properties measured. One material used an intermediate grade graphite fiber in all directions (Amoco P55) while a second material used very high thermal conductive fiber (Amoco K-1100) in the high fiber density direction. The overall void was less than 20%. Strength as measured by four-point bending was comparable to those of SiC/SiC composite. The room temperature thermal conductivity in the high conductivity direction was impressive for both materials, with values >70 W/m K for the P-55 and >420 W/m K for the K-1100 variant. The thermal conductivity was measured as a function of temperature and exceeds the highest thermal conductivity of CVD SiC currently available at fusion relevant temperatures (>600 deg. C). Limited data on the irradiation-induced degradation in thermal conductivity is consistent with carbon fiber composite literature

Mast Cells and Nerve Signal Conduction in Acupuncture

Directory of Open Access Journals (Sweden)

Na Yin

2018-01-01

Full Text Available Nerve and mast cells are densely distributed around acupoints in connective tissue. To explore the internal relations between them in acupuncture effect, we examined dorsal root potential (DRP response to acupuncture at Zusanli (ST36 under sodium cromoglicate (DSCG, a mast cell stabilizer intervention in anesthetized Sprague-Dawley (SD rats. We used single unit nerve recording techniques to collect nerve signals from DRP afferent nerves for a 45-minute period that includes 4 stages, that is, base, drug absorption, acupuncture, and recovery stages. We analyzed the recorded signals from time-domain and frequency-domain perspectives. The results showed that once acupuncture needle was inserted, twisting needle excited more nerves discharges than those at base discharges in ACU (from 35.1 ± 7.2 to 47 ± 9.2 Hz, P=0.004, and there existed the same trend in Saline + ACU group (from 23.8 ± 2.6 to 29.8 ± 4.2 Hz, P=0.059. There was no change of nerve discharges under twisting needle with injection of DSCG (from 34.8 ± 5.3 to 34.7 ± 4.4 Hz, P=0.480. We conclude that acupuncture manipulation promotes neural signal production and DSCG could partly inhibit nerve discharges.

Laser-activated protein solder for peripheral nerve repair

Science.gov (United States)

Trickett, Rodney I.; Lauto, Antonio; Dawes, Judith M.; Owen, Earl R.

1995-05-01

A 100 micrometers core optical fiber-coupled 75 mW diode laser operating at a wavelength of 800 nm has been used in conjunction with a protein solder to stripe weld severed rat tibial nerves, reducing the long operating time required for microsurgical nerve repair. Welding is produced by selective laser denaturation of the albumin based solder which contains the dye indocyanine green. Operating time for laser soldering was 10 +/- 5 min. (n equals 20) compared to 23 +/- 9 min. (n equals 10) for microsuturing. The laser solder technique resulted in patent welds with a tensile strength of 15 +/- 5 g, while microsutured nerves had a tensile strength of 40 +/- 10 g. Histopathology of the laser soldered nerves, conducted immediately after surgery, displayed solder adhesion to the outer membrane with minimal damage to the inner axons of the nerves. An in vivo study is under way comparing laser solder repaired tibial nerves to conventional microsuture repair. At the time of submission 15 laser soldered nerves and 7 sutured nerves were characterized at 3 months and showed successful regeneration with compound muscle action potentials of 27 +/- 8 mV and 29 +/- 8 mW respectively. A faster, less damaging and long lasting laser based anastomotic technique is presented.

Metabolic Changes in the Visual Cortex Are Linked to Retinal Nerve Fiber Layer Thinning in Multiple Sclerosis

Science.gov (United States)

Schubert, Florian; Bock, Markus; Walaszek, Bernadeta; Waiczies, Helmar; Schwenteck, Thomas; Dörr, Jan; Bellmann-Strobl, Judith; Mohr, Christian; Weinges-Evers, Nicholetta; Ittermann, Bernd; Wuerfel, Jens T.; Paul, Friedemann

2011-01-01

Objective To investigate the damage to the retinal nerve fiber layer as part of the anterior visual pathway as well as an impairment of the neuronal and axonal integrity in the visual cortex as part of the posterior visual pathway with complementary neuroimaging techniques, and to correlate our results to patients' clinical symptoms concerning the visual pathway. Design, Subjects and Methods Survey of 86 patients with relapsing-remitting multiple sclerosis that were subjected to retinal nerve fiber layer thickness (RNFLT) measurement by optical coherence tomography, to a routine MRI scan including the calculation of the brain parenchymal fraction (BPF), and to magnetic resonance spectroscopy at 3 tesla, quantifying N-acetyl aspartate (NAA) concentrations in the visual cortex and normal-appearing white matter. Results RNFLT correlated significantly with BPF and visual cortex NAA, but not with normal-appearing white matter NAA. This was connected with the patients' history of a previous optic neuritis. In a combined model, both BPF and visual cortex NAA were independently associated with RNFLT. Conclusions Our data suggest the existence of functional pathway-specific damage patterns exceeding global neurodegeneration. They suggest a strong interrelationship between damage to the anterior and the posterior visual pathway. PMID:21494672

Association between retinal nerve fiber layer thickness and magnetic resonance imaging findings and intelligence in patients with multiple sclerosis.

Science.gov (United States)

Ashtari, Fereshteh; Emami, Parisa; Akbari, Mojtaba

2015-01-01

Multiple Sclerosis (MS) is a neurological disease in which demyelination and axonal loss leads to progressive disability. Cognition impairment is among the most common complication. Studying axonal loss in the retina is a new marker for MS. The main goal of our study is to search for correlations between magnetic resonance imaging (MRI) findings and the retinal nerve fiber layer (RNFL) thickness at the macula and head of the optic nerve and Wechsler Adult Intelligence Scale-Revised (WAIS-R) Scores that assess multiple domains of intelligence, and to explore the relationship between changes in the RNFL thickness with intellectual and cognitive dysfunction. A prospective cross-sectional study was conducted at the University Hospital of Kashani, Isfahan, Iran, from September to December 2013. All patients were assessed with a full-scale intelligence quotient (IQ) on the WAIS-R. An optical coherence tomography study and brain MRI were performed in the same week for all the patients. Statistical analysis was conducted by using a bivariate correlation, by utilizing SPSS 20.0. A P value ≤ 0.05 was the threshold of statistical significance. Examination of a 100 patients showed a significant correlation between the average RNFL thickness of the macula and the verbal IQ (P value = 0.01) and full IQ (P value = 0.01). There was a significant correlation between brain atrophy and verbal IQ. The RNFL loss was correlated with verbal IQ and full IQ.

Challenges associated with nerve conduction block using kilohertz electrical stimulation

Science.gov (United States)

Patel, Yogi A.; Butera, Robert J.

2018-06-01

Neuromodulation therapies, which electrically stimulate parts of the nervous system, have traditionally attempted to activate neurons or axons to restore function or alleviate disease symptoms. In stark contrast to this approach is inhibiting neural activity to relieve disease symptoms and/or restore homeostasis. One potential approach is kilohertz electrical stimulation (KES) of peripheral nerves—which enables a rapid, reversible, and localized block of conduction. This review highlights the existing scientific and clinical utility of KES and discusses the technical and physiological challenges that must be addressed for successful translation of KES nerve conduction block therapies.

CAPSAICIN-SENSITIVE SENSORY NERVE FIBERS CONTRIBUTE TO THE GENERATION AND MAINTENANCE OF SKELETAL FRACTURE PAIN

OpenAIRE

Jimenez-Andrade, Juan Miguel; Bloom, Aaron P.; Mantyh, William G.; Koewler, Nathan J.; Freeman, Katie T.; Delong, David; Ghilardi, Joseph R.; Kuskowski, Michael A.; Mantyh, Patrick W.

2009-01-01

Although skeletal pain can have a marked impact on a patient’s functional status and quality of life, relatively little is known about the specific populations of peripheral nerve fibers that drive non-malignant bone pain. In the present report, neonatal male Sprague Dawley rats were treated with capsaicin or vehicle and femoral fracture was produced when the animals were young adults (15–16 weeks old). Capsaicin treatment, but not vehicle, resulted in a significant (>70%) depletion in the de...

Electrical conductivity of short carbon fibers and carbon black-reinforced chloroprene rubber

International Nuclear Information System (INIS)

Khoshniat, A. R.; MirAli, M.; Hemmati, M.; Afshar Taromi, F.; Katbab, A.

2002-01-01

Elastomers and plastics are intrinsically insulating materials, but by addition of some conductive particles such as conductive carbon black, carbon fibers and metals, they can change to conductive form. Conductivity of these composites are due to formation of the lattices of conductive filler particles in polymer chains. In this report, conductivity of chloroprene rubber filled with carbon black and carbon fibers as a function of temperature and pressure are studied. Electrical conductivity of chloroprene in a function of temperature and pressure are studied. Electrical conductivity of chloroprene in the presence of carbon black with proper mixing conditions increases to the conductivity level of semiconductors and even in the presence of carbon fibers it increases to the level of a conductor material. Meanwhile, the sensitivity of this compound to heat and pressure rises. Thus these composites have found various applications in the manufacture of heat and pressure sensitive sensors

Evaluation of Morphological and Functional Nerve Recovery of Rat Sciatic Nerve with a Hyaff11-Based Nerve Guide

Directory of Open Access Journals (Sweden)

K. Jansen

2006-01-01

Full Text Available Application of a Hyaff11-based nerve guide was studied in rats. Functional tests were performed to study motor nerve recovery. A withdrawal reflex test was performed to test sensory recovery. Morphology was studied by means of histology on explanted tissue samples. Motor nerve recovery was established within 7 weeks. Hereafter, some behavioral parameters like alternating steps showed an increase in occurence, while others remained stable. Sensory function was observed within the 7 weeks time frame. Nerve tissue had bridged the 10-mm gap within 7 weeks. The average nerve fiber surface area increased significantly in time. In situ degradation of the nerve conduit was fully going on at week 7 and tubes had collapsed by then. At weeks 15 and 21, the knitted tube wall structure was completely surrounded by macrophages and giant cells, and matrix was penetrating the tube wall. We conclude that a Hyaff11-based nerve guide can be used to bridge short peripheral nerve defects in rat. However, adaptations need to be made.

The application of fuzzy-based methods to central nerve fiber imaging

DEFF Research Database (Denmark)

Axer, Hubertus; Jantzen, Jan; Keyserlingk, Diedrich Graf v.

2003-01-01

This paper discusses the potential of fuzzy logic methods within medical imaging. Technical advances have produced imaging techniques that can visualize structures and their functions in the living human body. The interpretation of these images plays a prominent role in diagnostic and therapeutic...... decisions, so physicians must deal with a variety of image processing methods and their applications.This paper describes three different sources of medical imagery that allow the visualization of nerve fibers in the human brain: (1) an algorithm for automatic segmentation of some parts of the thalamus....... Fuzzy logic methods were applied to analyze these pictures from low- to high-level image processing. The solutions presented here are motivated by problems of routine neuroanatomic research demonstrating fuzzy-based methods to be valuable tools in medical image processing....

Oscillatory conductive heat transfer for a fiber in an ideal gas

Science.gov (United States)

Kuntz, H. L.; Perreira, N. D.

1985-01-01

A description of the thermal effects created by placing a cylindrical fiber in an inviscid, ideal gas, through which an acoustic wave propagates, is presented. The fibers and the gas have finite heat capacities and thermal conductivities. Expressions for the temperature distribution in the gas and in the material are determined. The temperature distribution is caused by pressure oscillations in the gas which, in turn, are caused by the passage of an acoustic wave. The relative value of a dimensionless parameter is found to be indicative of whether the exact or approximate equations should be used in the solution. This parameter is a function of the thermal conductivities and heat capacities of the fiber and gas, the acoustic frequency, and the fiber diameter.

Gallic acid and exercise training improve motor function, nerve conduction velocity but not pain sense reflex after experimental sciatic nerve crush in male rats.

Science.gov (United States)

Hajimoradi, Maryam; Fazilati, Mohammad; Gharib-Naseri, Mohammad Kazem; Sarkaki, Alireza

2015-01-01

The aim of present study was to evaluate the effects of oral administration of gallic acid (GA) for 21 days alone and in combination with exercise on nerve conduction velocity and sensory and motor functions in rats with sciatic nerve crush. Seventy adult male Wistar rats (250-300 g) were divided randomly into 7 groups with 10 in each: 1) Control (Cont), 2) Crushed + Vehicle (Cr +Veh), 3-5) Crushed + gallic acid (Cr+GA) (50, 100, and 200 mg/kg/2 mL, orally), 6) Crushed + exercise (Cr+Exe), and 7) Crushed + exercise + effective dose of gallic acid (Cr+Exe +GA200) for 21 days. In order to establish an animal model of sciatic nerve crush, equivalent to 7 kg of force pressed on 2-3 mm of sciatic nerve for 30 s, three times with 30 s intervals. Pain sense reflex in hot plate, motor coordination in rotarod, and sciatic nerve conduction velocity (SNCV) in all groups were tested. Data were analyzed using one-way ANOVA followed by Tukey's post hoc test and preflex latency was not changed in treated groups. Motor coordination and SNCV were improved in groups Cr+GA200 and Cr+Exe + GA200 (p<0.05, p<0.01 vs. Cr+Veh). GA, dose-dependently, may have therapeutic potential to improve the peripheral nerve degeneration, which is most likely related, at least in part, to its antioxidant and therapeutic properties.

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

NARCIS (Netherlands)

L.S. Duraku (Liron); S.M. Hossaini (Mehdi); S. Hoendervangers (Sieske); H.E. Falke; S. Kambiz (Shoista); V. Mudera (Vivek); J.C. Holstege (Jan); E.T. Walbeehm (Erik); T.J.H. Ruigrok (Tom)

2012-01-01

textabstractThe 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

The Electrical and Thermal Conductivity of Woven Pristine and Intercalated Graphite Fiber-Polymer Composites

Science.gov (United States)

Gaier, James R.; Vandenburg, Yvonne Yoder; Berkebile, Steven; Stueben, Heather; Balagadde, Frederick

2002-01-01

A series of woven fabric laminar composite plates and narrow strips were fabricated from a variety of pitch-based pristine and bromine intercalated graphite fibers in an attempt to determine the influence of the weave on the electrical and thermal conduction. It was found generally that these materials can be treated as if they are homogeneous plates. The rule of mixtures describes the resistivity of the composite fairly well if it is realized that only the component of the fibers normal to the equipotential surface will conduct current. When the composite is narrow with respect to the fiber weave, however, there is a marked angular dependence of the resistance which was well modeled by assuming that the current follows only along the fibers (and not across them in a transverse direction), and that the contact resistance among the fibers in the composite is negligible. The thermal conductivity of composites made from less conductive fibers more closely followed the rule of mixtures than that of the high conductivity fibers, though this is thought to be an artifact of the measurement technique. Electrical and thermal anisotropy could be induced in a particular region of the structure by weaving together high and low conductivity fibers in different directions, though this must be done throughout all of the layers of the structure as interlaminar conduction precludes having only the top layer carry the anisotropy. The anisotropy in the thermal conductivity is considerably less than either that predicted by the rule of mixtures or the electrical resistivity.

Effective thermal conductivity of glass-fiber board and blanket standard reference materials

International Nuclear Information System (INIS)

Smith, D.R.; Hust, J.G.

1983-01-01

This chapter reports on measurements of effective thermal conductivity performed on a series of specimens of glass-fiber board and glass-fiber blanket. Explains that measurements of thermal conductivity were conducted as a function of temperature from 85 to 360 K, of temperature difference with T=10 to 100 K, of bulk density from 11 to 148 kg/m 3 and for nitrogen, argon, and helium inter-fiber fill gases at pressures from atmospheric to high vacuum. Analyzes and compares results with values from the published literature and National Bureau of Standards (NBS) certification data for similar material. Gives polynomial expressions for the functional relation between conductivity, temperature, and density for board and for blanket

Functional role of peripheral opioid receptors in the regulation of cardiac spinal afferent nerve activity during myocardial ischemia

Science.gov (United States)

Longhurst, John C.

2013-01-01

Thinly myelinated Aδ-fiber and unmyelinated C-fiber cardiac sympathetic (spinal) sensory nerve fibers are activated during myocardial ischemia to transmit the sensation of angina pectoris. Although recent observations showed that myocardial ischemia increases the concentrations of opioid peptides and that the stimulation of peripheral opioid receptors inhibits chemically induced visceral and somatic nociception, the role of opioids in cardiac spinal afferent signaling during myocardial ischemia has not been studied. The present study tested the hypothesis that peripheral opioid receptors modulate cardiac spinal afferent nerve activity during myocardial ischemia by suppressing the responses of cardiac afferent nerve to ischemic mediators like bradykinin and extracellular ATP. The nerve activity of single unit cardiac afferents was recorded from the left sympathetic chain (T2–T5) in anesthetized cats. Forty-three ischemically sensitive afferent nerves (conduction velocity: 0.32–3.90 m/s) with receptive fields in the left and right ventricles were identified. The responses of these afferent nerves to repeat ischemia or ischemic mediators were further studied in the following protocols. First, epicardial administration of naloxone (8 μmol), a nonselective opioid receptor antagonist, enhanced the responses of eight cardiac afferent nerves to recurrent myocardial ischemia by 62%, whereas epicardial application of vehicle (PBS) did not alter the responses of seven other cardiac afferent nerves to ischemia. Second, naloxone applied to the epicardial surface facilitated the responses of seven cardiac afferent nerves to epicardial ATP by 76%. Third, administration of naloxone enhanced the responses of seven other afferent nerves to bradykinin by 85%. In contrast, in the absence of naloxone, cardiac afferent nerves consistently responded to repeated application of ATP (n = 7) or bradykinin (n = 7). These data suggest that peripheral opioid peptides suppress the

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 ...

Transplantation of bone-marrow-derived cells into a nerve guide resulted in transdifferentiation into Schwann cells and effective regeneration of transected mouse sciatic nerve.

Science.gov (United States)

Pereira Lopes, Fátima Rosalina; Frattini, Flávia; Marques, Suelen Adriani; Almeida, Fernanda Martins de; de Moura Campos, Lenira Camargo; Langone, Francesco; Lora, Silvano; Borojevic, Radovan; Martinez, Ana Maria Blanco

2010-10-01

Peripheral nerves possess the capacity of self-regeneration after traumatic injury. Nevertheless, the functional outcome after peripheral-nerve regeneration is often poor, especially if the nerve injuries occur far from their targets. Aiming to optimize axon regeneration, we grafted bone-marrow-derived cells (BMDCs) into a collagen-tube nerve guide after transection of the mouse sciatic nerve. The control group received only the culture medium. Motor function was tested at 2, 4, and 6 weeks after surgery, using the sciatic functional index (SFI), and showed that functional recovery was significantly improved in animals that received the cell grafts. After 6 weeks, the mice were anesthetized, perfused transcardially, and the sciatic nerves were dissected and processed for transmission electron microscopy and light microscopy. The proximal and distal segments of the nerves were compared, to address the question of improvement in growth rate; the results revealed a maintenance and increase of nerve regeneration for both myelinated and non-myelinated fibers in distal segments of the experimental group. Also, quantitative analysis of the distal region of the regenerating nerves showed that the numbers of myelinated fibers, Schwann cells (SCs) and g-ratio were significantly increased in the experimental group compared to the control group. The transdifferentiation of BMDCs into Schwann cells was confirmed by double labeling with S100/and Hoechst staining. Our data suggest that BMDCs transplanted into a nerve guide can differentiate into SCs, and improve the growth rate of nerve fibers and motor function in a transected sciatic-nerve model.

Retinal ganglion cell-inner plexiform and nerve fiber layers in neuromyelitis optica.

Science.gov (United States)

Hu, Sai-Jing; Lu, Pei-Rong

2018-01-01

To determine the thickness of the retinal ganglion cell-inner plexiform layer (GCIPL) and the retinal nerve fiber layer (RNFL) in patients with neuromyelitis optica (NMO). We conducted a cross-sectional study that included 30 NMO patients with a total of 60 eyes. Based on the presence or absence of optic neuritis (ON), subjects were divided into either the NMO-ON group (30 eyes) or the NMO-ON contra group (10 eyes). A detailed ophthalmologic examination was performed for each group; subsequently, the GCIPL and the RNFL were measured using high-definition optical coherence tomography (OCT). In the NMO-ON group, the mean GCIPL thickness was 69.28±21.12 µm, the minimum GCIPL thickness was 66.02±10.02 µm, and the RNFL thickness were 109.33±11.23, 110.47±3.10, 64.92±12.71 and 71.21±50.22 µm in the superior, inferior, temporal and nasal quadrants, respectively. In the NMO-ON contra group, the mean GCIPL thickness was 85.12±17.09 µm, the minimum GCIPL thickness was 25.39±25.1 µm, and the RNFL thicknesses were 148.33±23.22, 126.36±23.45, 82.21±22.30 and 83.36±31.28 µm in the superior, inferior, temporal and nasal quadrants, respectively. In the control group, the mean GCIPL thickness was 86.98±22.37 µm, the minimum GCIPL thickness was 85.28±10.75 µm, and the RNFL thicknesses were 150.22±22.73, 154.79±60.23, 82.33±7.01 and 85.62±13.81 µm in the superior, inferior, temporal and nasal quadrants, respectively. The GCIPL and RNFL were thinner in the NMO-ON contra group than in the control group ( P deviation (MD) and corrected pattern standard deviation (PSD) in the NMO-ON group ( P <0.05). The thickness of the GCIPL and RNFL, as measured using OCT, may indicate optic nerve damage in patients with NMO.

An electron microscopic study of intraepithelial nerves of oral mucosa of rats during aging

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Choi, Dai Ho; You, Dong Soo

1984-01-01

Observation made in this study bring home salient features that may contribute towards a better understanding of the relationship between the available physiologic data and anatomical characteristics of those nerve fibers that penetrate into the intraepithelial space in the oral cavity. The present investigation characterized the fine structure of nerve fibers in oral mucosae with respect to the manner in which presumed sensory fibers enter into the intraepithelial space by penetration of the basal lamina. The conclusions were made little discernible qualitative difference exists between young and old animals, concerning the fine structural characteristics of nerve fibers and nerve endings and in old animals, significant reductions exist in the number of neural elements in the intraepithelial space.

Alteração da camada de fibras nervosas da retina em usuários crônicos de cloroquina Retinal nerve fiber layer alteration in chronic users of chloroquine

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Daniela de Almeida Lyra Antunes

2005-04-01

Full Text Available OBJETIVOS: Avaliar a camada de fibras nervosas da retina (CFN por meio da polarimetria a laser, em pacientes em uso crônico de cloroquina. MÉTODOS: Foram estudados 44 olhos de 22 pacientes em uso de cloroquina por doenças reumatológicas, por pelo menos um ano. Como controle, foram incluídos vinte indivíduos sem uso de cloroquina com idade, gênero e raça similares. Foram excluídos os pacientes que apresentavam história familiar de hipertensão ocular ou glaucoma. Ambos os olhos foram submetidos à análise da camada de fibras nervosas da retina, com o aparelho GDx® Nerve Fiber Analyser, pelo mesmo examinador. RESULTADOS: Nos usuários crônicos de cloroquina, verificou-se alteração em mais de dois parâmetros do GDx em 28 olhos (63,6%. Ocorreu também alteração no gráfico "Deviation from normal" com perda de fibras nervosas em 11 olhos (25%. Quando comparado com o grupo controle, os parâmetros que demonstraram diferença estatisticamente significante foram: Superior Ratio, Inferior Ratio, Superior Nasal, Elipse Modulation, The Number, Superior Average e Superior Integral. Houve também associação estatisticamente significante entre o tempo de uso de cloroquina e perda da CFN. CONCLUSÕES: Comprovou-se a associação entre o uso crônico da cloroquina e a alteração da CFN detectada pelo GDx. Desta forma, esses resultados podem contribuir para o diagnóstico precoce da perda de fibras nervosas na retinopatia por cloroquina.PURPOSES: To evaluate the retina nerve fiber layer by laser polarimetry in patients in chronic use of chloroquine. METHODS: Forty-four eyes of twenty-two patients were studied. These were in use of chloroquine due to rheumatic diseases during at least one year. As a control group, twenty patients without use of chloroquine with similar characteristics (age, gender and race were included. Patients who had a family history of ocular hypertension or glaucoma were not included in this group. Both eyes were

Waveform efficiency analysis of auditory nerve fiber stimulation for cochlear implants

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Navaii, Mehdi Lotfi; Sadhedi, Hamed; Jalali, Mohsen

2013-01-01

Evaluation of the electrical stimulation efficiency of various stimulating waveforms is an important issue for efficient neural stimulator design. Concerning the implantable micro devices design, it is also necessary to consider the feasibility of hardware implementation of the desired waveforms. In this paper, the charge, power and energy efficiency of four waveforms (i.e. square, rising ramp, triangular and rising ramp-decaying exponential) in various durations have been simulated and evaluated based on the computational model of the auditory nerve fibers. Moreover, for a fair comparison of their feasibility, a fully integrated current generator circuit has been developed so that the desired stimulating waveforms can be generated. The simulation results show that stimulation with the square waveforms is a proper choice in short and intermediate durations while the rising ramp-decaying exponential or triangular waveforms can be employed for long durations.

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

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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.

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

Partial recovery of respiratory function and diaphragm reinnervation following unilateral vagus nerve to phrenic nerve anastomosis in rabbits.

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Junxiang Wen

Full Text Available Respiratory dysfunction is the leading cause of mortality following upper cervical spinal cord injury (SCI. Reinnervation of the paralyzed diaphragm via an anastomosis between phrenic nerve and a donor nerve is a potential strategy to mitigate ventilatory deficits. In this study, anastomosis of vagus nerve (VN to phrenic nerve (PN in rabbits was performed to assess the potential capacity of the VN to compensate for lost PN inputs. At first, we compared spontaneous discharge pattern, nerve thickness and number of motor fibers between these nerves. The PN exhibited a highly rhythmic discharge while the VN exhibited a variable frequency discharge pattern. The rabbit VN had fewer motor axons (105.3±12.1 vs. 268.1±15.4. Nerve conduction and respiratory function were measured 20 weeks after left PN transection with or without left VN-PN anastomosis. Compared to rabbits subjected to unilateral phrenicotomy without VN-PN anastomosis, diaphragm muscle action potential (AP amplitude was improved by 292%, distal latency by 695%, peak inspiratory flow (PIF by 22.6%, peak expiratory flow (PRF by 36.4%, and tidal volume by 21.8% in the anastomosis group. However, PIF recovery was only 28.0%, PEF 28.2%, and tidal volume 31.2% of Control. Our results suggested that VN-PN anastomosis is a promising therapeutic strategy for partial restoration of diaphragm reinnervation, but further modification and improvements are necessary to realize the full potential of this technique.

Numerical Investigation of Characteristic of Anisotropic Thermal Conductivity of Natural Fiber Bundle with Numbered Lumens

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Guan-Yu Zheng

2014-01-01

Full Text Available Natural fiber bundle like hemp fiber bundle usually includes many small lumens embedded in solid region; thus, it can present lower thermal conduction than that of conventional fibers. In the paper, characteristic of anisotropic transverse thermal conductivity of unidirectional natural hemp fiber bundle was numerically studied to determine the dependence of overall thermal property of the fiber bundle on that of the solid region phase. In order to efficiently predict its thermal property, the fiber bundle was embedded into an imaginary matrix to form a unit composite cell consisting of the matrix and the fiber bundle. Equally, another unit composite cell including an equivalent solid fiber was established to present the homogenization of the fiber bundle. Next, finite element thermal analysis implemented by ABAQUS was conducted in the two established composite cells by applying proper thermal boundary conditions along the boundary of unit cell, and influences of the solid region phase and the equivalent solid fiber on the composites were investigated, respectively. Subsequently, an optional relationship of thermal conductivities of the natural fiber bundle and the solid region was obtained by curve fitting technique. Finally, numerical results from the obtained fitted curves were compared with the analytic Hasselman-Johnson’s results and others to verify the present numerical model.

Conduction block of mammalian myelinated nerve by local cooling to 15–30°C after a brief heating

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Zhang, Zhaocun; Lyon, Timothy D.; Kadow, Brian T.; Shen, Bing; Wang, Jicheng; Lee, Andy; Kang, Audry; Roppolo, James R.; de Groat, William C.

2016-01-01

This study aimed at understanding thermal effects on nerve conduction and developing new methods to produce a reversible thermal block of axonal conduction in mammalian myelinated nerves. In 13 cats under α-chloralose anesthesia, conduction block of pudendal nerves (n = 20) by cooling (5–30°C) or heating (42–54°C) a small segment (9 mm) of the nerve was monitored by the urethral striated muscle contractions and increases in intraurethral pressure induced by intermittent (5 s on and 20 s off) electrical stimulation (50 Hz, 0.2 ms) of the nerve. Cold block was observed at 5–15°C while heat block occurred at 50–54°C. A complete cold block up to 10 min was fully reversible, but a complete heat block was only reversible when the heating duration was less than 1.3 ± 0.1 min. A brief (block at 50–54°C or 15 min of nonblock mild heating at 46–48°C significantly increased the cold block temperature to 15–30°C. The effect of heating on cold block fully reversed within ∼40 min. This study discovered a novel method to block mammalian myelinated nerves at 15–30°C, providing the possibility to develop an implantable device to block axonal conduction and treat many chronic disorders. The effect of heating on cold block is of considerable interest because it raises many basic scientific questions that may help reveal the mechanisms underlying cold or heat block of axonal conduction. PMID:26740534

Modeling the cost-benefit of nerve conduction studies in pre-employment screening for carpal tunnel syndrome.

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Evanoff, Bradley; Kymes, Steve

2010-06-01

The aim of this study was to evaluate the costs associated with pre-employment nerve conduction testing as a screening tool for carpal tunnel syndrome (CTS) in the workplace. We used a Markov decision analysis model to compare the costs associated with a strategy of screening all prospective employees for CTS and not hiring those with abnormal nerve conduction, versus a strategy of not screening for CTS. The variables included in our model included employee turnover rate, the incidence of CTS, the prevalence of median nerve conduction abnormalities, the relative risk of developing CTS conferred by abnormal nerve conduction screening, the costs of pre-employment screening, and the worker's compensation costs to the employer for each case of CTS. In our base case, total employer costs for CTS from the perspective of the employer (cost of screening plus costs for workers' compensation associated with CTS) were higher when screening was used. Median costs per employee position over five years were US$503 for the screening strategy versus US$200 for a no-screening strategy. A sensitivity analysis showed that a strategy of screening was cost-beneficial from the perspective of the employer only under a few circumstances. Using Monte Carlo simulation varying all parameters, we found a 30% probability that screening would be cost-beneficial. A strategy of pre-employment screening for CTS should be carefully evaluated for yield and social consequences before being implemented. Our model suggests such screening is not appropriate for most employers.

4.7-T diffusion tensor imaging of acute traumatic peripheral nerve injury.

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Boyer, Richard B; Kelm, Nathaniel D; Riley, D Colton; Sexton, Kevin W; Pollins, Alonda C; Shack, R Bruce; Dortch, Richard D; Nanney, Lillian B; Does, Mark D; Thayer, Wesley P

2015-09-01

Diagnosis and management of peripheral nerve injury is complicated by the inability to assess microstructural features of injured nerve fibers via clinical examination and electrophysiology. Diffusion tensor imaging (DTI) has been shown to accurately detect nerve injury and regeneration in crush models of peripheral nerve injury, but no prior studies have been conducted on nerve transection, a surgical emergency that can lead to permanent weakness or paralysis. Acute sciatic nerve injuries were performed microsurgically to produce multiple grades of nerve transection in rats that were harvested 1 hour after surgery. High-resolution diffusion tensor images from ex vivo sciatic nerves were obtained using diffusion-weighted spin-echo acquisitions at 4.7 T. Fractional anisotropy was significantly reduced at the injury sites of transected rats compared with sham rats. Additionally, minor eigenvalues and radial diffusivity were profoundly elevated at all injury sites and were negatively correlated to the degree of injury. Diffusion tensor tractography showed discontinuities at all injury sites and significantly reduced continuous tract counts. These findings demonstrate that high-resolution DTI is a promising tool for acute diagnosis and grading of traumatic peripheral nerve injuries.

The human dorsal spinocerebellar tract: myelinated fiber spectrum and fiber density in controls, autosomal dominant spinocerebellar atrophy, Huntington's chorea, radiation myelopathy, and diseases with peripheral sensory nerve involvement

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Ringelstein, E.B.; Schroeder, J.M.

1982-01-01

The human dorsal spinocerebellar tract (DSCT) was evaluated morphometrically in 14 control cases of different age and sex using semithin sections of epon-embedded cross sections from the C3, T5, and T10 segments of the spinal cord. A bimodal fiber spectrum was revealed with one peak at 2-3 microns, and a second, broader peak at about 6-8 microns. Fiber density at C3 was 11,188 fibers/mm2 and at T5, 11,156 fibers/mm2. Regression analysis relating fiber density to age disclosed a highly significant loss of myelinated fibers at T5 amounting to about 2.5% per decade. A severe reduction of fiber density and a distinct change in the fiber spectrum with predominant loss of large myelinated fibers were noted in a case of autosomal dominant spinocerebellar atrophy with late onset, and, to a lesser degree, in a case of Huntington's chorea. A subtotal loss of fibers with a persistent normal distribution of fiber sizes was observed rostral to a focus of severe radiation myelopathy, indicating Wallerian degeneration of large numbers of fibers, and a reduction of fiber diameters caudal to the lesion, suggesting retrograde fiber change. By contrast, no primary or transneural changes in the DSCT were detected in six cases of long-term alcoholism, carcinomatous sensory neuropathy, and neurofibromatosis in spite of the involvement of numerous nerve roots.

Electrophysiology of Cranial Nerve Testing: Spinal Accessory and Hypoglossal Nerves.

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Stino, Amro M; Smith, Benn E

2018-01-01

Multiple techniques have been developed for the electrodiagnostic evaluation of cranial nerves XI and XII. Each of these carries both benefits and limitations, with more techniques and data being available in the literature for spinal accessory than hypoglossal nerve evaluation. Spinal accessory and hypoglossal neuropathy are relatively uncommon cranial mononeuropathies that may be evaluated in the outpatient electrodiagnostic laboratory setting. A review of available literature using PubMed was conducted regarding electrodiagnostic technique in the evaluation of spinal accessory and hypoglossal nerves searching for both routine nerve conduction studies and repetitive nerve conduction studies. The review provided herein provides a resource by which clinical neurophysiologists may develop and implement clinical and research protocols for the evaluation of both of these lower cranial nerves in the outpatient setting.

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

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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.

The visceromotor and somatic afferent nerves of the penis.

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Diallo, Djibril; Zaitouna, Mazen; Alsaid, Bayan; Quillard, Jeanine; Ba, Nathalie; Allodji, Rodrigue Sètchéou; Benoit, Gérard; Bedretdinova, Dina; Bessede, Thomas

2015-05-01

Innervation of the penis supports erectile and sensory functions. This article aims to study the efferent autonomic (visceromotor) and afferent somatic (sensory) nervous systems of the penis and to investigate how these systems relate to vascular pathways. Penises obtained from five adult cadavers were studied via computer-assisted anatomic dissection (CAAD). The number of autonomic and somatic nerve fibers was compared using the Kruskal-Wallis test. Proximally, penile innervation was mainly somatic in the extra-albugineal sector and mainly autonomic in the intracavernosal sector. Distally, both sectors were almost exclusively supplied by somatic nerve fibers, except the intrapenile vascular anastomoses that accompanied both somatic and autonomic (nitrergic) fibers. From this point, the neural immunolabeling within perivascular nerve fibers was mixed (somatic labeling and autonomic labeling). Accessory afferent, extra-albugineal pathways supplied the outer layers of the penis. There is a major change in the functional type of innervation between the proximal and distal parts of the intracavernosal sector of the penis. In addition to the pelvis and the hilum of the penis, the intrapenile neurovascular routes are the third level where the efferent autonomic (visceromotor) and the afferent somatic (sensory) penile nerve fibers are close. Intrapenile neurovascular pathways define a proximal penile segment, which guarantees erectile rigidity, and a sensory distal segment. © 2015 International Society for Sexual Medicine.

Semi-conducting material obtained from natural fiber modified with PAni

International Nuclear Information System (INIS)

Rocha, Eli V. da; Silva Junior, Fernando Gomes; Oliveira, Geiza E.; Pinto, Jose Carlos

2009-01-01

The surface of natural Brazilian Amazonic fibers (curaua, Ananas erectifolius) was modified with polyaniline nanoparticles, through in-situ preparation of polyaniline nanoparticles in presence of the curaua fibers. As it was shown here, this modification allowed a very significant increase of the electrical conductivity of the fibers (about 2.500 times). The modified materials were also characterized by FTIR (Fourier Transform Infrared Spectroscopy), AFM (Atomic Force Microscopy) and SAXS (Small Angle X-ray Scattering) and the obtained results were used to explain some of the chemical and morphological aspects of the materials. (author)

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.

Whole mount preparation of the adult Drosophila ventral nerve cord for giant fiber dye injection.

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Boerner, Jana; Godenschwege, Tanja A

2011-06-04

To analyze the axonal and dendritic morphology of neurons, it is essential to obtain accurate labeling of neuronal structures. Preparing well labeled samples with little to no tissue damage enables us to analyze cell morphology and to compare individual samples to each other, hence allowing the identification of mutant anomalies. In the demonstrated dissection method the nervous system remains mostly inside the adult fly. Through a dorsal incision, the abdomen and thorax are opened and most of the internal organs are removed. Only the dorsal side of the ventral nerve cord (VNC) and the cervical connective (CvC) containing the big axons of the giant fibers (GFs) are exposed, while the brain containing the GF cell body and dendrites remains in the intact head. In this preparation most nerves of the VNC should remain attached to their muscles. Following the dissection, the intracellular filling of the giant fiber (GF) with a fluorescent dye is demonstrated. In the CvC the GF axons are located at the dorsal surface and thus can be easily visualized under a microscope with differential interference contrast (DIC) optics. This allows the injection of the GF axons with dye at this site to label the entire GF including the axons and their terminals in the VNC. This method results in reliable and strong staining of the GFs allowing the neurons to be imaged immediately after filling with an epifluorescent microscope. Alternatively, the fluorescent signal can be enhanced using standard immunohistochemistry procedures suitable for high resolution confocal microscopy.

[The technique of hearing reconstruction in the cases of conductive hearing loss with malformed tympanic segment of facial nerve].

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Yang, Feng; Song, Rendong; Liu, Yang

2016-02-02

To explore the technique of hearing reconstruction in the cases of conductive hearing loss with malformed tympanic segment of facial nerve. Data of 10 cases from July 2010 to March 2015 were collected.The status of tympanic segment of facial nerve, malformed ossicles and the reconstructed methods of ossicular chain were analyzed and discussed based on the embryo anatomy and surgical technique. All facial nerves in 10 cases were exposed and drooping to stapes or cover the oval window.Three patients who had normal stapes, pushed by the exposed facial nerve, were reconstructed with partial ossicular replacement prostheses (PORP). Two patients who had footplate, with partial fixation, were reconstructed with total ossicular replacement prostheses (TORP). Three patients who had atresia of the oval window were implanted with Piston after being made hole in the atresia plate.Another two cases who had atresia of the oval window were implanted with TORP after promontory being drilled out.All cases had no injury of facial nerve and nervous hearing, and no tinnitus.Nine cases had conductive hearing improvement, except one with promontory drilled out. Patients who had conductive hearing loss with malformed tympanic segment of facial nerve can be treated by the technique of hearing reconstruction.The fenestration technique in the bottom of the scala tympani of the basal turn provides us a new method for treating patients whose oval window was fully covered by malformed facial nerve.

Which nerve conduction parameters can predict spontaneous electromyographic activity in carpal tunnel syndrome?

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Chang, Chia-Wei; Lee, Wei-Ju; Liao, Yi-Chu; Chang, Ming-Hong

2013-11-01

We investigate electrodiagnostic markers to determine which parameters are the best predictors of spontaneous electromyographic (EMG) activity in carpal tunnel syndrome (CTS). We enrolled 229 patients with clinically proven and nerve conduction study (NCS)-proven CTS, as well as 100 normal control subjects. All subjects were evaluated using electrodiagnostic techniques, including median distal sensory latencies (DSLs), sensory nerve action potentials (SNAPs), distal motor latencies (DMLs), compound muscle action potentials (CMAPs), forearm median nerve conduction velocities (FMCVs) and wrist-palm motor conduction velocities (W-P MCVs). All CTS patients underwent EMG examination of the abductor pollicis brevis (APB) muscle, and the presence or absence of spontaneous EMG activities was recorded. Normal limits were determined by calculating the means ± 2 standard deviations from the control data. Associations between parameters from the NCS and EMG findings were investigated. In patients with clinically diagnosed CTS, abnormal median CMAP amplitudes were the best predictors of spontaneous activity during EMG examination (p95% (positive predictive rate >95%). If the median CMAP amplitude was higher than the normal limit (>4.9 mV), the rate of no spontaneous EMG activity was >94% (negative predictive rate >94%). An abnormal SNAP amplitude was the second best predictor of spontaneous EMG activity (p<0.001; OR 4.13; 95% CI 2.16-7.90), and an abnormal FMCV was the third best predictor (p=0.01; OR 2.10; 95% CI 1.20-3.67). No other nerve conduction parameters had significant power to predict spontaneous activity upon EMG examination. The CMAP amplitudes of the APB are the most powerful predictors of the occurrence of spontaneous EMG activity. Low CMAP amplitudes are strongly associated with spontaneous activity, whereas high CMAP amplitude are less associated with spontaneous activity, implying that needle EMG examination should be recommended for the detection of

Prostaglandin E1 in conjunction with high doses of vitamin B12 improves nerve conduction velocity of patients with diabetic peripheral neuropathy

Institute of Scientific and Technical Information of China (English)

Jilai Li; Zhirong Wan

2008-01-01

BACKGROUND: Prostaglandin E1 improves diabetic peripheral neuropathy in symptoms and sensory threshold. Vitamin B1 and methyl-vitamin B12 improve microcirculation to peripheral nerve tissue and promote neurotrophy.OBJECTIVE: To observe motor nerve and sensory nerve conduction velocity in patients with diabetic peripheral neuropathy, prior to and after treatment with prostaglandin E1, vitamin B1 and different doses of vitamin B12.DESIGN, TIME AND SETTING: Randomized, controlled experiment, performed at the Department of Neurology. Beijing Hantian Central Hospital, between February 2002 and September 2007.PARTICIPANTS: A total of 122 patients with type 2 diabetic peripheral neuropathy; 73 males and 49 females were included. All patients met the diagnostic criteria of diabetes mellitus, as determined by the World Health Organization in 1999 and 2006, and also the diagnostic criteria of diabetic peripheral neuropathy. For each subject, conduction disorders in the median nerve and in the common peroneal nerve were observed using electromyogram. Also, after diet and drug treatment, the blood glucose level of subjects was observed to be at a satisfactory level for more than two weeks, and the symptoms of diabetic peripheral neuropathy were not alleviated.METHODS: All patients were randomly divided into the following three groups. A control group (n=40), in which, 100mg vitamin B1 and 500μg vitamin B12 were intramuscularly injected. A vitamin B12 low-dose treated group (n=42), in which 10μg prostaglandin E1 in 250mL physiological saline was intravenously injected once a day and 100mg vitamin B1 and 500μg vitamin B12 was intramuscularly injected once a day. Lastly, a vitamin B12 high-dose treated group (n=40), in which administration was the same as in the vitamin B12 low-dose treated group, except that 500μg vitamin B12 was replaced by 1mg vitamin B12. Administration was performed for four weeks for each group.MAIN OUTCOME MEASURES: The motor nerve and sensory nerve

Anatomic assessment of sympathetic peri-arterial renal nerves in man.

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Sakakura, Kenichi; Ladich, Elena; Cheng, Qi; Otsuka, Fumiyuki; Yahagi, Kazuyuki; Fowler, David R; Kolodgie, Frank D; Virmani, Renu; Joner, Michael

2014-08-19

Although renal sympathetic denervation therapy has shown promising results in patients with resistant hypertension, the human anatomy of peri-arterial renal nerves is poorly understood. The aim of our study was to investigate the anatomic distribution of peri-arterial sympathetic nerves around human renal arteries. Bilateral renal arteries were collected from human autopsy subjects, and peri-arterial renal nerve anatomy was examined by using morphometric software. The ratio of afferent to efferent nerve fibers was investigated by dual immunofluorescence staining using antibodies targeted for anti-tyrosine hydroxylase and anti-calcitonin gene-related peptide. A total of 10,329 nerves were identified from 20 (12 hypertensive and 8 nonhypertensive) patients. The mean individual number of nerves in the proximal and middle segments was similar (39.6 ± 16.7 per section and 39.9 ± 1 3.9 per section), whereas the distal segment showed fewer nerves (33.6 ± 13.1 per section) (p = 0.01). Mean subject-specific nerve distance to arterial lumen was greatest in proximal segments (3.40 ± 0.78 mm), followed by middle segments (3.10 ± 0.69 mm), and least in distal segments (2.60 ± 0.77 mm) (p renal sympathetic nerve fibers is lower in distal segments and dorsal locations. There is a clear predominance of efferent nerve fibers, with decreasing prevalence of afferent nerves from proximal to distal peri-arterial and renal parenchyma. Understanding these anatomic patterns is important for refinement of renal denervation procedures. Copyright © 2014 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Distribution of serotonergic and dopaminergic nerve fibers in the salivary gland complex of the cockroach Periplaneta americana

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Kühnel Dana

2002-06-01

Full Text Available Abstract Background The cockroach salivary gland consists of secretory acini with peripheral ion-transporting cells and central protein-producing cells, an extensive duct system, and a pair of reservoirs. Salivation is controled by serotonergic and dopaminergic innervation. Serotonin stimulates the secretion of a protein-rich saliva, dopamine causes the production of a saliva without proteins. These findings suggest a model in which serotonin acts on the central cells and possibly other cell types, and dopamine acts selectively on the ion-transporting cells. To examine this model, we have analyzed the spatial relationship of dopaminergic and serotonergic nerve fibers to the various cell types. Results The acinar tissue is entangled in a meshwork of serotonergic and dopaminergic varicose fibers. Dopaminergic fibers reside only at the surface of the acini next to the peripheral cells. Serotonergic fibers invade the acini and form a dense network between central cells. Salivary duct segments close to the acini are locally associated with dopaminergic and serotonergic fibers, whereas duct segments further downstream have only dopaminergic fibers on their surface and within the epithelium. In addition, the reservoirs have both a dopaminergic and a serotonergic innervation. Conclusion Our results suggest that dopamine is released on the acinar surface, close to peripheral cells, and along the entire duct system. Serotonin is probably released close to peripheral and central cells, and at initial segments of the duct system. Moreover, the presence of serotonergic and dopaminergic fiber terminals on the reservoir indicates that the functions of this structure are also regulated by dopamine and serotonin.

Effects of Xueshuantong combined with antioxidant drugs on nerve conduction function and oxidative stress in patients with diabetic peripheral neuropathy

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Yuan-Zhen Chu

2017-07-01

Full Text Available Objective: To study the effect of Xueshuantong combined with antioxidant drugs on nerve conduction function and oxidative stress in patients with diabetic peripheral neuropathy. Methods: 138 cases of patients with diabetic peripheral neuropathy who were treated in endocrinology department of our hospital between June 2014 and October 2016 were enrolled and randomly divided into two groups. The combination group received Xueshuantong combined with antioxidant drug therapy, and the control group received antioxidant drug therapy. Before and after treatment, the nerve conduction velocity as well as serum content of oxidative stress indexes and nerve cytokines was measured. Results: 4 weeks and 8 weeks after treatment, common peroneal nerve and median nerve MNCV and SNCV as well as serum SOD, GSH-Px, HO-1, CAT, CNTF, BDNF and SDF-1α levels of both groups were significantly higher than those before treatment while serum MDA, AOPP and 8-OHdG levels were significantly lower than those before treatment, and common peroneal nerve and median nerve MNCV and SNCV as well as serum SOD, GSH-Px, HO-1, CAT, CNTF, BDNF and SDF-1α levels of combination group were significantly higher than those of control group while serum MDA, AOPP and 8-OHdG levels were significantly lower than those of control group. Conclusion: Xueshuantong combined with antioxidant drugs can improve the nerve conduction function, inhibit oxidative stress response and improve neurotrophy status in patients with diabetic peripheral neuropathy.

Median nerve conduction velocity and central conduction time measured with somatosensory evoked potentials in thyroxine-treated infants with Down syndrome

NARCIS (Netherlands)

van Trotsenburg, A. S. Paul; Smit, Bert J.; Koelman, Johannes H. T. M.; Dekker-van der Sloot, Marijke; Ridder, Jeannette C. D.; Tijssen, Jan G. P.; de Vijlder, Jan J. M.; Vulsma, Thomas

2006-01-01

OBJECTIVE: The aim of this study was to determine whether thyroxine treatment would improve nerve conduction in infants with Down syndrome. METHODS: A single-center, nationwide, randomized, double-blind, clinical trial was performed. Neonates with Down syndrome were assigned randomly to thyroxine (N

Baseline effects of lysophosphatidylcholine and nerve growth factor in a rat model of sciatic nerve regeneration after crush injury

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Ryan L Wood

2018-01-01

Full Text Available Schwann cells play a major role in helping heal injured nerves. They help clear debris, produce neurotrophins, upregulate neurotrophin receptors, and form bands of Büngner to guide the healing nerve. But nerves do not always produce enough neurotrophins and neurotrophin receptors to repair themselves. Nerve growth factor (NGF is an important neurotrophin for promoting nerve healing and lysophosphatidylcholine (LPC has been shown to stimulate NGF receptors (NGFR. This study tested the administration of a single intraneural injection of LPC (1 mg/mL for single LPC injection and 10 mg/mL for multiple LPC injections at day 0 and one (day 7, two (days 5 and 7, or three (days 5, 7, and 9 injections of NGF (160 ng/mL for single injections and 80 ng/mL for multiple injections to determine baseline effects on crushed sciatic nerves in rats. The rats were randomly divided into four groups: control, crush, crush-NGF, and crush-LPC-NGF. The healing of the nerves was measured weekly by monitoring gait; electrophysiological parameters: compound muscle action potential (CMAP amplitudes; and morphological parameters: total fascicle areas, myelinated fiber counts, fiber densities, fiber packing, and mean g-ratio values at weeks 3 and 6. The crush, crush-NGF, and crush-LPC-NGF groups statistically differed from the control group for all six weeks for the electrophysiological parameters but only differed from the control group at week 3 for the morphological parameters. The crush, crush-NGF, and crush-LPC-NGF groups did not differ from each other over the course of the study. Single injections of LPC and NGF one week apart or multiple treatments of NGF at 5, 7 and 9 days post-injury did not alter the healing rate of the sciatic nerves during weeks 1-6 of the study. These findings are important to define the baseline effects of NGF and LPC injections, as part of a larger effort to determine the minimal dose regimen of NGF to regenerate peripheral nerves.

Design of barrier coatings on kink-resistant peripheral nerve conduits

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Basak Acan Clements

2016-02-01

Full Text Available Here, we report on the design of braided peripheral nerve conduits with barrier coatings. Braiding of extruded polymer fibers generates nerve conduits with excellent mechanical properties, high flexibility, and significant kink-resistance. However, braiding also results in variable levels of porosity in the conduit wall, which can lead to the infiltration of fibrous tissue into the interior of the conduit. This problem can be controlled by the application of secondary barrier coatings. Using a critical size defect in a rat sciatic nerve model, the importance of controlling the porosity of the nerve conduit walls was explored. Braided conduits without barrier coatings allowed cellular infiltration that limited nerve recovery. Several types of secondary barrier coatings were tested in animal studies, including (1 electrospinning a layer of polymer fibers onto the surface of the conduit and (2 coating the conduit with a cross-linked hyaluronic acid-based hydrogel. Sixteen weeks after implantation, hyaluronic acid-coated conduits had higher axonal density, displayed higher muscle weight, and better electrophysiological signal recovery than uncoated conduits or conduits having an electrospun layer of polymer fibers. This study indicates that braiding is a promising method of fabrication to improve the mechanical properties of peripheral nerve conduits and demonstrates the need to control the porosity of the conduit wall to optimize functional nerve recovery.

Strength and conductivity of unidirectional copper composites reinforced by continuous SiC fibers

International Nuclear Information System (INIS)

Kimmig, S.; Allen, I.; You, J.H.

2013-01-01

A SiC long fiber-reinforced copper composite offers a beneficial combination of high strength and high thermal conductivity at elevated temperatures. Both properties make the composite a promising material for the heat sink of high-heat-flux components. In this work, we developed a novel Cu/SiC f composite using the Sigma fiber. Based on HIP technique, a metallurgical process was established for fabricating high quality specimens using a TiC interface coating. Extensive tensile tests were conducted on the unidirectionally reinforced composite at 20 °C and 300 °C for a wide range of fiber volume fraction (V f ). In this paper, a large amount of test data is presented. The transversal thermal conductivity varies from 260 to 130 W/mK at 500 °C as V f is increased from 13% to 37%. The tensile strength reached up to 1246 MPa at 20 °C for V f = 37.6%, where the fracture strain was limited to 0.8%. The data of both elastic modulus and ultimate strength exhibited a good agreement with the rule-of-mixture predictions indicating a high quality of the materials. The strength of the composite with the Sigma fibers turned out to be superior to those of the SCS6 fibers at 300 °C, although the SCS6 fiber actually has a higher strength than the Sigma fiber. The fractographic pictures of tension test and fiber push-out test manifested a sufficient interfacial bonding

Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect.

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Luo, Lihua; Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan; Wang, Xiong; Huselstein, Celine; Chen, Yun

2015-02-20

Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

Laser-activated protein bands for peripheral nerve repair

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Lauto, Antonio; Trickett, Rodney I.; Malik, Richard; Dawes, Judith M.; Owen, Earl R.

1996-01-01

A 100 micrometer core optical fiber-coupled 75 mW diode laser operating at a wavelength of 800 nm has been used in conjunction with a protein solder to stripe weld severed rat tibial nerves, reducing the long operating time required for microsurgical nerve repair. Welding is produced by selective laser denaturation of the protein based solder which contains the dye indocyanine green. Operating time for laser soldering was 10 plus or minus 5 min. (n equals 24) compared to 23 plus or minus 9 min (n equals 13) for microsuturing. The laser solder technique resulted in patent welds with a tensile strength of 15 plus or minus 5 g, while microsutured nerves had a tensile strength of 40 plus or minus 10 g. Histopathology of the laser soldered nerves, conducted immediately after surgery, displayed solder adhesion to the outer membrane with minimal damage to the inner axons of the nerves. An in vivo study, with a total of fifty-seven adult male wistar rats, compared laser solder repaired tibial nerves to conventional microsuture repair. Twenty-four laser soldered nerves and thirteen sutured nerves were characterized at three months and showed successful regeneration with average compound muscle action potentials (CMAP) of 2.4 plus or minus 0.7 mV and 2.7 plus or minus 0.8 mV respectively. Histopathology of the in vivo study, confirmed the comparable regeneration of axons in laser and suture operated nerves. A faster, less damaging and long lasting laser based anastomotic technique is presented.

Omental pedicle transposition and suture repair of peripheral nerve ...

African Journals Online (AJOL)

Abu wael

This study aimed to compare the effectiveness of omental pedicle transposition and ... Assessment of the nerve regeneration was based on functional (motor and sensory), ..... peripheral nerve fibers regenerating after crush, multiple crush, and.

Functional Nerve Preservation in Extracranial Head and Neck Schwannoma Surgery.

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Ijichi, Kei; Kawakita, Daisuke; Maseki, Shinichiro; Beppu, Shintaro; Takano, Gaku; Murakami, Shingo

2016-05-01

A schwannoma is an uncommon, benign neurogenic tumor of Schwann cells. Tumor enucleation is the recommended surgical method to preserve function of the original nerve, although enucleation does not guarantee completely intact nerve function after the operation. To establish a strategy for functional preservation in extracranial head and neck schwannoma treatment by using an electromyographic (EMG) system during tumor resection. A retrospective cohort study was conducted of 15 patients who underwent surgery for removal of schwannoma tumors between April 1, 2006, and March 31, 2015, at an academic tertiary referral center. Data analysis was conducted from April 3, 2006, to September 15, 2015. Neurogenic tumors were diagnosed according to preoperative findings, and during surgery tumors were exposed and given EMG-controlled electrical stimulation to analyze their origins. In motor nerve cases, the electrical activity of the muscle was measured and recorded by EMG. The tumor was then enucleated by incision along tumor fibers mapped using EMG stimulation. If a nerve bundle was visible, we incised along there and enucleated the tumor. A strategy using electrical stimulation to improve preservation of nerve function in extracranial head and neck schwannoma operations. Frequency and duration of postoperative neurologic complications associated with functional preservation surgery with tumor enucleation was evaluated using EMG monitoring according to tumor origin. Of the 15 patients with extracranial schwannoma, 9 (60%) were women (mean [SD] age, 36.3 [15.3] years). All 15 patients underwent surgery using a transcervical approach. The most common nerves of origin were the vagus nerve and the sympathetic chain. In sensory or sympathetic nerve cases, the EMG response was absent. Two of 5 patients with vagus schwannoma had postoperative temporary vocal nerve palsy. These symptoms showed improvement after 1 year. There was no tumor recurrence during the follow-up period in any

Thermal conductivity and retention characteristics of composites made of boron carbide and carbon fibers with extremely high thermal conductivity for first wall armour

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Jimbou, R.; Kodama, K.; Saidoh, M.; Suzuki, Y.; Nakagawa, M.; Morita, K.; Tsuchiya, B.

1997-02-01

The thermal conductivity of the composite hot-pressed at 2100°C including B 4C and carbon fibers with a thermal conductivity of 1100 W/ m· K was nearly the same as that of the composite including carbon fibers with a thermal conductivity of 600 W/ m· K. This resulted from the higher amount of B diffused into the carbon fibers through the larger interface. The B 4C content in the composite can be reduced from 35 to 20 vol% which resulted from the more uniform distribution of B 4C by stacking the flat cloth woven of carbon fibers (carbon fiber plain fabrics) than in the composite with 35 vol% B 4C including curled carbon fiber plain fabrics. The decrease in the B 4C content does not result in the degradation of D (deuterium)-retention characteristics or D-recycling property, but will bring about the decreased amount of the surface layer to be melted under the bombardment of high energy hydrogen ions such as disruptions because of higher thermal conduction of the composite.

[Experimental study on regeneration of sciatic nerve injury with physical therapy].

Science.gov (United States)

Zhao, Juan; Yu, Hong; Xu, Yiming; Bai, Yuehong

2011-01-01

Peripheral nerve injury is a common clinical disease, to study the effects of the physical therapy on the regeneration of the injured sciatic nerve, and provide a reference for clinical treatment. Sixty-four female adult Wistar rats (weighing 252-365 g) were chosen and randomly divided into 4 groups (n = 16): group A, group B, group C, and group D. The experimental model of sciatic nerve defect was established by crushing the right sciatic nerve in groups B, C, and D; group A served as the control group without crushing. At 2 days after injury, no treatment was given in group B, electrical stimulation in group C, and combined physical therapies (decimeter and infrared ray) in group D. At 0, 7, 14, and 30 days after treatment, the sciatic nerve function index (SFI) and the motor nerve conduction velocity (MNCV) were measured, and morphological and transmission electron microscopy (TEM) examinations were done; at 30 days after treatment, the morphological evaluation analysis of axons was performed. At 0 and 7 days after treatment, the SFI values of groups B, C, and D were significantly higher than that of group A (P 0.05) at 30 days; whereas the SFI values of groups B and C decreased, showing significant difference when compared with the value of group A (P 0.05). At 0 and 7 days, only collagen and lipid were observed by TEM; at 14 and 30 days, many Schwann cells and perineurial cells in regeneration axon were observed in groups B, C, and D, especially in group D. Automated image analysis of axons showed that there was no significant difference in the number of myelinated nerve fibers, axon diameter, and myelin sheath thickness between group D and group A (P > 0.05), and the number of myelinated nerve fibers and axon diameter of group D were significantly higher than those of groups B and C (P < 0.05). Physical therapy can improve the regeneration of the injured sciatic nerve of rats.

Serum levels of TGF-β1 in patients of diabetic peripheral neuropathy and its correlation with nerve conduction velocity in type 2 diabetes mellitus.

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Hussain, Gauhar; Rizvi, S Aijaz Abbas; Singhal, Sangeeta; Zubair, Mohammad; Ahmad, Jamal

2016-01-01

To correlate serum levels of TGF-β1 with motor and sensory nerve conduction velocities in patients of type 2 diabetes mellitus The study was conducted in diagnosed type 2 diabetes mellitus patients which were divided in patients with clinically detectable peripheral neuropathy of shorter duration (n=37) and longer duration (n=27). They were compared with patients without clinical neuropathy (n=22). Clinical diagnosis was based on neuropathy symptom score (NSS) and Neuropathy disability score (NDS) for signs. Blood samples were collected for baseline investigations and estimation of serum TGF-β1. Nerve conduction velocity was measured in both upper and lower limbs. Median, Ulnar, Common Peroneal and Posterior Tibial nerves were selected for motor nerve conduction study and Median and Sural nerves were selected for sensory nerve conduction study In patients of type 2 diabetes mellitus with clinically detectable and serum TGF-β1 showed positive correlation with nerve conduction velocities High level of TGF-β1 in serum of T2DM patients with neuropathy show possible contribution in development of neuropathy. Due to its independent association this cytokine might be used as biomarker for diabetic peripheral neuropathy. Copyright © 2015 Diabetes India. Published by Elsevier Ltd. All rights reserved.

High Spatial Resolution Imaging Mass Spectrometry of Human Optic Nerve Lipids and Proteins

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Anderson, David M. G.; Spraggins, Jeffrey M.; Rose, Kristie L.; Schey, Kevin L.

2015-06-01

The human optic nerve carries signals from the retina to the visual cortex of the brain. Each optic nerve is comprised of approximately one million nerve fibers that are organized into bundles of 800-1200 fibers surrounded by connective tissue and supportive glial cells. Damage to the optic nerve contributes to a number of blinding diseases including: glaucoma, neuromyelitis optica, optic neuritis, and neurofibromatosis; however, the molecular mechanisms of optic nerve damage and death are incompletely understood. Herein we present high spatial resolution MALDI imaging mass spectrometry (IMS) analysis of lipids and proteins to define the molecular anatomy of the human optic nerve. The localization of a number of lipids was observed in discrete anatomical regions corresponding to myelinated and unmyelinated nerve regions as well as to supporting connective tissue, glial cells, and blood vessels. A protein fragment from vimentin, a known intermediate filament marker for astrocytes, was observed surrounding nerved fiber bundles in the lamina cribrosa region. S100B was also found in supporting glial cell regions in the prelaminar region, and the hemoglobin alpha subunit was observed in blood vessel areas. The molecular anatomy of the optic nerve defined by MALDI IMS provides a firm foundation to study biochemical changes in blinding human diseases.

Cone dysfunctions in retinitis pigmentosa with retinal nerve fiber layer thickening.

Science.gov (United States)

Sobacı, Güngör; Ozge, Gökhan; Gündoğan, Fatih Ç

2012-01-01

To investigate whether or not thicker retinal nerve fiber layer (RNFL) in retinitis pigmentosa (RP) patients relates to functional abnormalities of the photoreceptors. Optical coherence tomography-based RNFL thickness was measured by Stratus-3™ (Zeiss, Basel, Switzerland) optical coherence tomography and electroretinogram (ERG) recordings made using the RETI-port(®) system (Roland, Wiesbaden, Germany) in 27 patients with retinitis pigmentosa and in 30 healthy subjects. Photopic ERG b-wave amplitude, cone ERG b-wave latency, 30 Hz flicker amplitude, and 30 Hz flicker latency had significant correlations to the RNFL-temporal (r = -0.55, P = 0.004, r = 0.68, P = 0.001, r = -0.65, P = 0.001, and r = -0.52, P = 0.007, respectively). Eyes with thicker RNFL (ten eyes) differed significantly from those with thinner RNFL (eight eyes) regarding cone ERG b-wave latency values only (P = 0.001). Thicker RNFL in patients with retinitis pigmentosa may be associated with functional abnormality of the cone system.

Sensory nerve conduction in the caudal nerves of rats with diabetes Condução nervosa sensorial no nervo caudal de ratos com diabetes experimental

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Celina Cordeiro de Carvalho

2011-04-01

Full Text Available PURPOSE: To investigate sensory nerve conduction of the caudal nerve in normal and diabetic rats. METHODS: Diabetes was induced in twenty 8-weeks old Wistar male rats. Twenty normal rats served as controls. Caudal nerve conduction studies were made before diabetes induction and the end of each week for six consecutive weeks. The caudal nerve was stimulated distally and nerve potentials were recorded proximally on the animal's tail using common "alligator" clips as surface electrodes. RESULTS: After induction, nerve conduction velocities (NCV increased slower in the diabetic than in the control group. Sensory nerve action potentials (SNAP conduction velocities increased slower in the diabetic than in the control group (slope of regression line: 0.5 vs 1.3m/s per week; NCV in the 15th week = 39±3m/s vs 44±4m/s. Tukey's tests showed differences between groups at the 11th, 13th and 15th weeks old. From the 10th week on, SNAP amplitudes increased faster in the diabetic than in the control group (slopes of the regression line: 10 vs 8µV per week; SNAP amplitudes in the 15th week: 107±23µV vs 85±13µV. Differences at the 12th, 13th and 15th weeks were significant. CONCLUSION: In diabetic rats nerve conduction velocities were slower whereas amplitudes were larger than in normal rats.OBJETIVO: Investigar a condução nervosa sensorial do nervo caudal em ratos normais e diabéticos. MÉTODOS: O diabetes foi induzido em vinte ratos Wistar com idade de oito semanas. Vinte ratos serviram como controle. Os estudos da condução do nervo caudal foram feitos antes da indução do diabetes e ao final de cada semana, durante seis semanas consecutivas. O nervo caudal foi estimulado distalmente e potenciais foram registrados proximalmente na cauda do animal, usando clipes comuns "jacaré" como eletrodos de superfície. RESULTADOS: Após a indução, a velocidade de condução nervosa (VCN aumentou mais lentamente no grupo diabético que no controle

Scanning Laser Polarimetry and Optical Coherence Tomography for Detection of Retinal Nerve Fiber Layer Defects

Science.gov (United States)

Oh, Jong-Hyun

2009-01-01

Purpose 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. Methods 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. Results 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. Conclusions 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. PMID:19794943

Transfer of obturator nerve for femoral nerve injury: an experiment study in rats.

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Meng, Depeng; Zhou, Jun; Lin, Yaofa; Xie, Zheng; Chen, Huihao; Yu, Ronghua; Lin, Haodong; Hou, Chunlin

2018-07-01

Quadriceps palsy is mainly caused by proximal lesions in the femoral nerve. The obturator nerve has been previously used to repair the femoral nerve, although only a few reports have described the procedure, and the outcomes have varied. In the present study, we aimed to confirm the feasibility and effectiveness of this treatment in a rodent model using the randomized control method. Sixty Sprague-Dawley rats were randomized into two groups: the experimental group, wherein rats underwent femoral neurectomy and obturator nerve transfer to the femoral nerve motor branch; and the control group, wherein rats underwent femoral neurectomy without nerve transfer. Functional outcomes were measured using the BBB score, muscle mass, and histological assessment. At 12 and 16 weeks postoperatively, the rats in the experimental group exhibited recovery to a stronger stretch force of the knee and higher BBB score, as compared to the control group (p nerve with myelinated and unmyelinated fibers was observed in the experimental group. No significant differences were observed between groups at 8 weeks postoperatively (p > 0.05). Obturator nerve transfer for repairing femoral nerve injury was feasible and effective in a rat model, and can hence be considered as an option for the treatment of femoral nerve injury.

Nerve ultrasound shows subclinical peripheral nerve involvement in neurofibromatosis type 2.

Science.gov (United States)

Telleman, Johan A; Stellingwerff, Menno D; Brekelmans, Geert J; Visser, Leo H

2018-02-01

Neurofibromatosis type 2 (NF2) is mainly associated with central nervous system (CNS) tumors. Peripheral nerve involvement is described in symptomatic patients, but evidence of subclinical peripheral nerve involvement is scarce. We conducted a cross-sectional pilot study in 2 asymptomatic and 3 minimally symptomatic patients with NF2 to detect subclinical peripheral nerve involvement. Patients underwent clinical examination, nerve conduction studies (NCS), and high-resolution ultrasonography (HRUS). A total of 30 schwannomas were found, divided over 20 nerve segments (33.9% of all investigated nerve segments). All patients had at least 1 schwannoma. Schwannomas were identified with HRUS in 37% of clinically unaffected nerve segments and 50% of nerve segments with normal NCS findings. HRUS shows frequent subclinical peripheral nerve involvement in NF2. Clinicians should consider peripheral nerve involvement as a cause of weakness and sensory loss in the extremities in patients with this disease. Muscle Nerve 57: 312-316, 2018. © 2017 Wiley Periodicals, Inc.

High-Performance Stretchable Conductive Composite Fibers from Surface-Modified Silver Nanowires and Thermoplastic Polyurethane by Wet Spinning.

Science.gov (United States)

Lu, Ying; Jiang, Jianwei; Yoon, Sungho; Kim, Kyung-Shik; Kim, Jae-Hyun; Park, Sanghyuk; Kim, Sang-Ho; Piao, Longhai

2018-01-17

Highly stretchable and conductive fibers have attracted great interest as a fundamental building block for the next generation of textile-based electronics. Because of its high conductivity and high aspect ratio, the Ag nanowire (AgNW) has been considered one of the most promising conducting materials for the percolation network-based conductive films and composites. However, the poor dispersibility of AgNWs in hydrophobic polymers has hindered their application to stretchable conductive composite fibers. In this paper, we present a highly stretchable and conductive composite fiber from the co-spinning of surface-modified AgNWs and thermoplastic polyurethane (PU). The surface modification of AgNWs with a polyethylene glycol derivative improved the compatibility of PU and AgNWs, which allowed the NWs to disperse homogeneously in the elastomeric matrix, forming effective percolation networks and causing the composite fiber to show enhanced electrical and mechanical performance. The maximum AgNW mass fraction in the composite fiber was 75.9 wt %, and its initial electrical conductivity was as high as 14 205 S/cm. The composite fibers also exhibited superior stretchability: the maximum rupture strain of the composite fiber with 14.6 wt % AgNW was 786%, and the composite fiber was also conductive even when it was stretched up to 200%. In addition, 2-dimensional (2-D) Ag nanoplates were added to the AgNW/PU composite fibers to increase the stability of the conductive network under repeated stretching and releasing. The Ag nanoplates acted as a bridge to effectively prevent the AgNWs from slippage and greatly improved the stability of the conductive network.

Imaging the Facial Nerve: A Contemporary Review

International Nuclear Information System (INIS)

Gupta, S.; Roehm, P.C.; Mends, F.; Hagiwara, M.; Fatterpekar, G.

2013-01-01

Imaging plays a critical role in the evaluation of a number of facial nerve disorders. The facial nerve has a complex anatomical course; thus, a thorough understanding of the course of the facial nerve is essential to localize the sites of pathology. Facial nerve dysfunction can occur from a variety of causes, which can often be identified on imaging. Computed tomography and magnetic resonance imaging are helpful for identifying bony facial canal and soft tissue abnormalities, respectively. Ultrasound of the facial nerve has been used to predict functional outcomes in patients with Bell’s palsy. More recently, diffusion tensor tractography has appeared as a new modality which allows three-dimensional display of facial nerve fibers

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.

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.

Construction of nerve guide conduits from cellulose/soy protein composite membranes combined with Schwann cells and pyrroloquinoline quinone for the repair of peripheral nerve defect

Energy Technology Data Exchange (ETDEWEB)

Luo, Lihua [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Center of Molecular Medicine, School of Medicine, Hubei University of Arts and Sciences, Xiangyang 441053 (China); Gan, Li; Liu, Yongming; Tian, Weiqun; Tong, Zan [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China); Wang, Xiong; Huselstein, Celine [Ingénierie Moléculaire et Physiopathologie Articulaire (IMoPA), UMR 7365 CNRS – Université de Lorraine, Biopôle, 54500 Vandoeuvre-lès-Nancy (France); Chen, Yun, E-mail: yunchen@whu.edu.cn [Department of Biomedical Engineering, School of Basic Medical Sciences, Wuhan University, Wuhan 430071 (China)

2015-02-20

Regeneration and functional reconstruction of peripheral nerve defects remained a significant clinical challenge. Nerve guide conduits, with seed cells or neurotrophic factors (NTFs), had been widely used to improve the repair and regeneration of injured peripheral nerve. Pyrroloquinoline quinone (PQQ) was an antioxidant that can stimulate nerve growth factors (NGFs) synthesis and accelerate the Schwann cells (SCs) proliferation and growth. In present study, three kinds of nerve guide conduits were constructed: one from cellulose/SPI hollow tube (CSC), another from CSC combined with SCs (CSSC), and the third one from CSSC combined with PQQ (CSSPC), respectively. And then they were applied to bridge and repair the sciatic nerve defect in rats, using autograft as control. Effects of different nerve guide conduits on the nerve regeneration were comparatively evaluated by general analysis, sciatic function index (SFI) and histological analysis (HE and TEM). Newly-formed regenerative nerve fibers were observed and running through the transparent nerve guide conduits 12 weeks after surgery. SFI results indicated that the reconstruction of motor function in CSSPC group was better than that in CSSC and CSC groups. HE images from the cross-sections and longitudinal-sections of the harvested regenerative nerve indicated that regenerative nerve fibers had been formed and accompanied with new blood vessels and matrix materials in the conduits. TEM images also showed that lots of fresh myelinated and non-myelinated nerve fibers had been formed. Parts of vacuolar, swollen and abnormal axons occurred in CSC and CSSC groups, while the vacuolization and swell of axons was the least serious in CSSPC group. These results indicated that CSSPC group had the most ability to repair and reconstruct the nerve structure and functions due to the comprehensive contributions from hollow CSC tube, SCs and PQQ. As a result, the CSSPC may have the potential for the applications as nerve guide

The effect of cryotherapy on nerve conduction velocity, pain threshold and pain tolerance.

Science.gov (United States)

Algafly, Amin A; George, Keith P

2007-06-01

To determine the impact of the application of cryotherapy on nerve conduction velocity (NCV), pain threshold (PTH) and pain tolerance (PTO). A within-subject experimental design; treatment ankle (cryotherapy) and control ankle (no cryotherapy). Hospital-based physiotherapy laboratory. A convenience sample of adult male sports players (n = 23). NCV of the tibial nerve via electromyogram as well as PTH and PTO via pressure algometer. All outcome measures were assessed at two sites served by the tibial nerve: one receiving cryotherapy and one not receiving cryotherapy. In the control ankle, NCV, PTH and PTO did not alter when reassessed. In the ankle receiving cryotherapy, NCV was significantly and progressively reduced as ankle skin temperature was reduced to 10 degrees C by a cumulative total of 32.8% (pCryotherapy led to an increased PTH and PTO at both assessment sites (pcryotherapy can increase PTH and PTO at the ankle and this was associated with a significant decrease in NCV. Reduced NCV at the ankle may be a mechanism by which cryotherapy achieves its clinical goals.

Electrical properties of conducting loads produced from polyaniline deposited in natural fibers and nanoclays

International Nuclear Information System (INIS)

Kosenhoski, Dirlaine; Saade, Wesley; Pinto, Camila P.; Becker, Daniela; Dalmolin, Carla; Pachekoski, Wagner M.

2015-01-01

Conducting polymers are known for their excellent magnetic and electrical properties, but they still are an expensive and limited choice to their use as a conducting load for composite materials. An alternative to optimize the electrical conductivity of polymeric composites is the deposition of a conducting polymer on materials already used as loads, as the deposition on natural fibers or the encapsulation of polymeric chains in the voids of host structures. In this work, bananastem fiber and montmorillonite nanoclay (MMT) were used as host structures for polyaniline synthesis in order to produce conducting loads. Samples were characterized by FT-IR and X-Rays Diffraction in order to confirm the formation of polyanilina / bananastem fibers or polyanilina / nanoclays loads. Influence on the electrical properties of the composites were evaluated by Electrochemical Impedance Spectroscopy (EIS), showing the maintenance of the electric conductivity of polyaniline and its potential use as a load for the formation of conducting composites. (author)

Tuning the conductivity and inner structure of electrospun fibers to promote cardiomyocyte elongation and synchronous beating.

Science.gov (United States)

Liu, Yaowen; Lu, Jinfu; Xu, Guisen; Wei, Jiaojun; Zhang, Zhibin; Li, Xiaohong

2016-12-01

The key to addressing the challenges facing cardiac tissue engineering is the integration of physical, chemical, and electrical cues into scaffolds. Aligned and conductive scaffolds have been fabricated as synthetic microenvironments to improve the function of cardiomyocytes. However, up to now, the influence of conductive capability and inner structure of fibrous scaffolds have not been determined on the cardiomyocyte morphologies and beating patterns. In the current study, highly aligned fibers were fabricated with loaded up to 6% of carbon nanotubes (CNTs) to modulate the electrical conductivity, while blend and coaxial electrospinning were utilized to create a bulk distribution of CNTs in fiber matrices and a spatial embedment in fiber cores, respectively. Conductive networks were formed in the fibrous scaffolds after the inoculation of over 3% CNTs, and the increase in the conductivity could maintain the cell viabilities, induce the cell elongation, enhance the production of sarcomeric α-actinin and troponin I, and promote the synchronous beating of cardiomyocytes. Although the conductivity of blend fibers is slightly higher than that of coaxial fibers with the same CNT loadings, the lower exposures to CNTs resulted in higher cell viability, elongation, extracellular matrix secretion and beating rates for cardiomyocytes on coaxial fibers. Taken altogether, core-sheath fibers with loaded 5% of CNTs in the fiber cores facilitated the cardiomyocyte growth with a production of organized contractile proteins and a pulsation frequency close to that of the atrium. It is suggested that electrospun scaffolds that couple conductivity and fibrous structure considerations may provide optimal stimuli to foster cell morphology and functions for myocardial regeneration or establishment of in vitro cardiomyocyte culture platform for drug screening. Copyright © 2016. Published by Elsevier B.V.

Optical Coherence Tomography in Optic Nerve Hypoplasia: Correlation With Optic Disc Diameter, Nerve Fiber Layer Thickness, and Visual Function.

Science.gov (United States)

Kelly, John P; Baran, Francine; Phillips, James O; Weiss, Avery H

2017-12-15

The correlation between optic disc diameters (DDs) with average retinal nerve fiber layer thickness (RNFLT) and visual function in children with optic nerve hypoplasia (ONH) having nystagmus is unknown. Data were obtained from a retrospective review of 28 children (mean age: 9.4 years; ±5.1). Optic DD was defined as the maximal horizontal opening of Bruch membrane with spectral optical coherence tomography combined with a confocal laser ophthalmoscope. Average RNFLT was obtained from circumpapillary b-scans. RNFLT was also remeasured at eccentricities that were proportionate with DD to rule out potential sampling artifacts. Visual function was assessed by visual acuity at last follow-up and by visual evoked potentials (VEP) in 11 patients. The eye with the larger DD, which had better visual acuity, was analyzed to exclude potential effects of amblyopia. DD was correlated with average RNFLT (r = 0.61), visual acuity (r = 0.32), and VEPs (r = 0.66). The relationship between RNFLT and DD was as follows: average RNFLT (μm) = 0.074 * DD (μm) - 18.8. RNFLT also correlated with the ratio of horizontal optic DD to macula-disc-margin distance (DD:DM; r = 0.59). RNFLT measured at eccentricities proportionate with DD showed progressive decrease in thickness only for DDs <1,100 μm. All patients with DD <1,000 μm had subnormal visual acuity, whereas those with DD <1,200 μm had subnormal VEPs. DD correlates with average RNFLT and with visual function in children with ONH. Using OCT imaging, DD can be obtained in children with nystagmus and provides objective information.

Peripapillary retinal nerve fiber layer and optic nerve head characteristics in eyes with situs inversus of the optic disc.

Science.gov (United States)

Kang, Sunah; Jin, Sunyoung; Roh, Kyu Hwa; Hwang, Young Hoon

2015-01-01

This study was performed to investigate the peripapillary retinal nerve fiber layer (RNFL) and optic nerve head (ONH) characteristics, as determined using a spectral-domain optical coherence tomography (OCT), in eyes with situs inversus of the optic disc. The peripapillary RNFL and the ONH were assessed in 12 eyes belonging to 6 subjects with situs inversus of the optic disc (situs inversus group) and 24 eyes in 12 age-matched, sex-matched, and refractive error-matched healthy subjects (control group) by using OCT. The average, quadrant, and clock-hour RNFL thicknesses (clock-hour 9 on the scan represented the temporal side of the optic disc in both eyes), the superior/inferior RNFL peak locations, and ONH characteristics such as disc area, rim area, cup-to-disc ratio, vertical cup-to-disc ratio, and cup volume were obtained. The differences in RNFL and ONH characteristics between the 2 groups were analyzed. The situs inversus group had a thicker RNFL in the clock-hour sectors 3 and 4, a thinner RNFL in the clock-hour sectors 7, 8, and 11, and more nasally located superior and inferior RNFL peak locations than the control group (P≤0.001). The situs inversus group had a smaller cup-to-disc area ratio, smaller vertical cup-to-disc ratio, and a lesser cup volume than the control group (Poptic disc showed different peripapillary RNFL and ONH characteristics from those without this abnormality. These findings should be considered when assessing eyes with situs inversus of the optic disc.

Dose volume relationships for intraoperatively irradiated saphenous nerve

International Nuclear Information System (INIS)

Gillette, E.L.; Powers, B.E.; Gillette, S.M.; Thames, H.D.; Childs, G.; Vujaskovic, Z.; LaRue, S.M.

1995-01-01

. Fifteen of 47 dogs treated using the 8 cm field were euthanatized for severe paresis prior to three years. There was a decreasing conduction velocity which correlated with increasing dose for dogs treated using an 8 cm field at 1, 2, and 3 years following treatment. There was no decrease in the mean conduction velocity for dogs treated with 2 cm fields; however, 5 of 38 dogs were euthanatized for severe paresis. No decrease in mean conduction velocity was observed in dogs treated to 4 cm and only 2 of 45 dogs were euthanatized due to paresis. At three years after IORT, the ED50 for greater than 50% nerve fiber loss and fibrosis was about 15 Gy for the 8 cm field, 25 Gy for the 4 cm field, and 33 Gy for the 2 cm field. Conclusions: There was both a strong dose response and volume effect for functional peripheral nerve injury. The latency of injury was inversely proportional to dose and was also inversely proportional to the volume treated

EFFECT OF INTRAVITREAL RANIBIZUMAB ON GANGLION CELL COMPLEX AND PERIPAPILLARY RETINAL NERVE FIBER LAYER IN NEOVASCULAR AGE-RELATED MACULAR DEGENERATION USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

Science.gov (United States)

Zucchiatti, Ilaria; Cicinelli, Maria V; Parodi, Maurizio Battaglia; Pierro, Luisa; Gagliardi, Marco; Accardo, Agostino; Bandello, Francesco

2017-07-01

To analyze the changes in ganglion cell complex and peripapillary retinal nerve fiber layer thickness, in central macular thickness and choroidal thickness on spectral domain optical coherence tomography in patients with neovascular age-related macular degeneration treated with intravitreal ranibizumab injections. All consecutive patients with untreated neovascular age-related macular degeneration received loading phase of three monthly intravitreal ranibizumab, followed by retreatments on a pro re nata protocol for 12 months. changes in ganglion cell complex and retinal nerve fiber layer at the end of follow-up. Secondary outcome: changes in best-corrected visual acuity, central macular thickness, and choroidal thickness at the end of follow-up. Choroidal thickness was measured at 500 μm, 1000 μm, and 1,500 μm intervals nasally, temporally, superiorly, and inferiorly to the fovea, respectively, on horizontal and vertical line scans centered on the fovea. Twenty-four eyes were included. Ganglion cell complex and peripapillary retinal nerve fiber layer thickness did not show statistically significant changes through 12 months (55.6 ± 18.5 and 81.9 ± 9.9 μm at baseline, 52.7 ± 19.3 and 84.6 ± 15.5 μm at month 12, P > 0.05). Central macular thickness showed progressive decrease from baseline to month 12, with maximum reduction at month 3 (P macular thickness was significantly reduced at the end of treatment. Further studies, with larger sample, longer follow-up, and greater number of injections, are warranted.

Nerve conduction velocity in human limbs with late sequelae after local cold injury.

Science.gov (United States)

Arvesen, A; Wilson, J; Rosén, L

1996-06-01

Cold-induced neuropathy may play a dominant role in the long-term sequelae with cold sensitivity after local cold injuries (LCIs). Somatosensory functions were assessed and nerve conduction velocity (NCV) and motor distal delay (MDD) were measured in the limbs of 31 Norwegian former soldiers with persistent cold intolerance 3-4 years after the primary LCI. NCV measurements were performed in 24 lower and 16 upper extremities. NCV was related to degree of overall subjective complaints quantified by means of a visual analogue scale (VAS). Motor (MNCV) and sensory conduction velocity (SNCV) in the lower extremities and SNCV in the hands were significantly decreased compared with controls. MDD was pathologically increased in the feet. NCV of the forearms ranged from normal to significant reduction. The more pronounced effect on the lower extremities may be caused by deeper cooling of the calves compared with forearms for several reasons. No significant associations were found between VAS and NCV except for the right median nerve. NCV measurements may provide objective findings in cold-injured patients and in those with few or no conspicuous clinical signs.

Alpha-synuclein in cutaneous small nerve fibers

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Siepmann T

2016-10-01

Full Text Available Timo Siepmann,1 Ben Min-Woo Illigens,2 Kristian Barlinn1 1Department of Neurology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; 2Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA Abstract: Despite progression in the development of pharmacological therapy, treatment of alpha synucleinopathies, such as Parkinson’s disease (PD and some atypical parkinsonism syndromes, is still challenging. To date, our knowledge of the mechanisms whereby the pathological form of alpha-synuclein causes structural and functional damage to the nervous system is limited and, consequently, there is a lack of specific diagnostic tools to evaluate pathology in these patients and differentiate PD from other neurodegenerative proteinopathies. Recent studies indicated that alpha-synuclein deposition in cutaneous small nerve fibers assessed by skin biopsies might be a valid disease marker of PD and facilitate early differentiation of PD from atypical parkinsonism syndromes. This observation is relevant since early diagnosis may enable timely treatment and improve quality of life. However, challenges include the necessity of standardizing immunohistochemical analysis techniques and the identification of potential distinct patterns of intraneural alpha-synuclein deposition among synucleinopathies. In this perspective, we explore the scientific and clinical opportunities arising from alpha-synuclein assessment using skin biopsies. These include elucidation of the peripheral nervous system pathology of PD and other synucleinopathies, identification of novel targets to study response to neuroprotective treatment, and improvement of clinical management. Furthermore, we discuss future challenges in exploring the diagnostic value of skin biopsy assessment for alpha-synuclein deposition and implementing the technique in clinical practice. Keywords: Parkinson’s disease, diagnosis, skin

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

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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.

Simulation of multipolar fiber selective neural stimulation using intrafascicular electrodes

NARCIS (Netherlands)

Meier, J.H.; Meier, Jan H.; Rutten, Wim; Zoutman, Arne E.; Boom, H.B.K.; Bergveld, Piet

1992-01-01

A realistic, quantitative model for the excitation of myelinated nerve fibers by intrafascicular electrodes is presented. It predicts the stimulatory regions of any configuration of any number of electrodes, positioned anywhere inside the fascicle. The model has two parts. First, the nerve fiber is

The gross anatomy of the renal sympathetic nerves revisited.

Science.gov (United States)

Mompeo, Blanca; Maranillo, Eva; Garcia-Touchard, Arturo; Larkin, Theresa; Sanudo, Jose

2016-07-01

Catheter-based renal denervation techniques focus on reducing blood pressure in resistant hypertension. This procedure requires exact knowledge of the anatomical interrelation between the renal arteries and the targeted renal nervous plexus. The aim of this work was to build on classical anatomical studies and describe the gross anatomy and anatomical relationships of the renal arteries and nerve supply to the kidneys in a sample of human cadavers. Twelve human cadavers (six males and six females), age range 73 to 94 years, were dissected. The nervous fibers and renal arteries were dissected using a surgical microscope. The renal plexus along the hilar renal artery comprised a fiber-ganglionic ring surrounding the proximal third of the renal artery, a neural network along the middle and distal thirds, and smaller accessory ganglia along the course of the nerve fibers. The fibers of the neural network were mainly located on the superior (95.83%) and inferior (91.66%) surfaces of the renal artery and they were sparsely interconnected by diagonal fibers. Polar arteries were present in 33.33% of cases and the renal nerve pattern for these was similar to that of the hilar arteries. Effective renal denervation needs to target the superior and inferior surfaces of the hilar and polar arteries, where the fibers of the neural network are present. Clin. Anat. 29:660-664, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Anastomose do nervo facial de coelhos com cola de fibrina: estudo da velocidade de condução nervosa Rabbit facial nerve anastomosis with fibrin glue: nerve conduction velocity evaluation

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Francisco Aurelio Lucchesi Sandrini

2007-04-01

Full Text Available OBJETIVO: Este estudo tem o objetivo de avaliar através da velocidade de condução nervosa com eletrodos de superfície a utilização da cola de fibrina na anastomose nervosa. MÉTODOS: Neste experimento, foram avaliadas as diferenças entre as velocidades de condução nervosa pré e pós-operatória do nervo facial esquerdo de 12 coelhos. Foi verificada a existência de correlação entre a velocidade de condução nervosa e o número de axônios regenerados no pós-operatório. Os nervos transeccionados foram unidos com cola de fibrina. O potencial de ação motora foi obtido com o uso de eletrodos de superfície. O eletrodo de estimulação foi colocado imediatamente à frente do pavilhão auditivo (tronco do nervo facial e o eletrodo de gravação foi colocado no músculo quadrado do lábio inferior. RESULTADOS: A média normal da velocidade de condução nervosa foi de 36,53 m/seg. Ao final do período, a velocidade de condução nervosa atingiu um valor de aproximadamente 81% do valor normal. Não foi observada correlação significativa entre a velocidade de condução nervosa pós-operatória e o número de axônios regenerados (p=0,146. CONCLUSÃO: A anastomose com cola de fibrina pode ser utilizada para anastomose nervosa no modelo animal e nervo estudados.AIM: The aim of this study was to evaluate the use of fibrin glue on nerve anastomosis, and study conduction velocity obtained by surface electrodes. METHODS: In this experimental model we evaluated nerve conduction velocity differences in the preoperative and postoperative periods, for the left facial nerve of 12 rabbits. Then, we evaluated whether there were correlations between conduction velocity and the number of postoperative regenerated axons. The sectioned nerves were anastomosed with fibrin glue. The muscle action potentials were obtained from surface electrodes. The stimulation electrode was placed immediately before the ear pinna (facial nerve trunk and the recording

Retinal Nerve Fiber Layer and Peripapillary Choroidal Thicknesses in Non-Glaucomatous Unilateral Optic Atrophy Compared with Unilateral Advanced Pseudoexfoliative Glaucoma.

Science.gov (United States)

Kucukevcilioglu, Murat; Ayyildiz, Onder; Aykas, Seckin; Gokce, Gokcen; Koylu, Mehmet Talay; Ozgonul, Cem; Ozge, Gokhan; Mumcuoglu, Tarkan; Yumusak, Erhan

2017-02-01

To investigate retinal nerve fiber layer thickness (RNFL-T) and peripapillary choroidal thickness (PC-T) in non-glaucomatous optic atrophy (OA) patients in comparison with unaffected and control eyes, furthermore, to compare thickness profiles with unilateral pseudoexfoliative advanced glaucoma. Thirty-three eyes with OA (Group A), 33 unaffected fellow eyes (Group B), 25 right eyes of 25 control subjects (Group C), and 15 eyes with advanced glaucoma (Group D) were enrolled. RNFL-T was measured in six regions by spectral-domain optical coherence tomography. Enhanced depth imaging optical coherence tomography was obtained to evaluate PC-T in corresponding regions. RNFL-T was significantly lower in Group A than in Groups B and C globally and at all peripapillary regions (all p temporal > nasal > inferior) profiles were almost identical to that in unaffected fellow eyes and control eyes. However, Group D showed different patterns with less regional differences in RNFL-T, and the greatest value of PC-T in nasal quadrant. Besides retinal nerve fiber layer thinning, non-glaucomatous OA is associated with choroidal thinning. The RNFL-T and PC-T profiles in advanced glaucoma eyes differed from the common patterns seen among OA eyes, unaffected fellow eyes, and control eyes.

Comparison of nerve conduction and injury degree in patients with lumbar disc herniation after microendoscopic discectomy and fenestration discectomy

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Jun Li

2017-09-01

Full Text Available Objective: To study the difference of nerve conduction and injury degree in patients with lumbar disc herniation after microendoscopic discectomy and fenestration discectomy. Methods: Patients with single-segment lumbar disc herniation who were treated in Dazhou Central Hospital between May 2014 and February 2017 were selected as the research subjects, the history data were reviewed and the operation methods were referred to divide them into FD group and MED group who received fenestration discectomy and microendoscopic discectomy respectively. The conduction velocity of common peroneal nerve and tibial nerve were detected before operation and 4 weeks after operation; serum levels of nerve and muscle injury-related molecules as well as inflammation and stress-related molecules were detected before operation and 3 days after operation. Results: MNCV levels of common peroneal nerve and tibial nerve 4 weeks after operation as well as serum CRP, TNF-α, MDA and AOPP contents 3 d after operation of both groups of patients were significantly higher than those before operation, and the MNCV levels of common peroneal nerve and tibial nerve of MED group 4 weeks after operation were significantly higher than those of FD group while serum CRP, TNF-α, MDA and AOPP contents of MED group 3 d after operation were not significantly different from those of FD group; serum NSE, S100B, Tau, pNF-H, CPK, Myo and LDH contents of FD patients 3 d after operation were significantly higher than those before operation while serum NSE, S100B, Tau, pNF-H, CPK, Myo and LDH contents of MED group were not significantly different from those before operation. Conclusion: Microendoscopic discectomy for lumbar disc herniation can relieve the nerve and muscle injury, and is equivalent to fenestration discectomy in activating the systemic stress and inflammatory response.

Utilization and yield of nerve conduction studies and electromyography in older adults

LENUS (Irish Health Repository)

Mello, S

2016-02-01

Older adults are at increased risk of both central and peripheral neurological disorders. Impaired nerve and muscle deficits contribute to morbidity and reduced quality of life. Our aim was to define the utilization and yield of nerve conduction studies (NCS) and electromyography (EMG) in older adults. We reviewed NCS and EMG records for all patients older than age 65 in the year 2012. Of 1,530 NCS and EMGs performed, 352 (23%) were in patients older than 65 (mean age 73.7, 52% male). Two hundred and eighty-eight (83.7%) of NCS were abnormal as were 102 (71.8%) of EMGs. The likelihood of having an abnormal test result increased with increasing age. The most common diagnosis was peripheral neuropathy 231 (65.4%). The incidence of peripheral neuropathy is particularly high in this age group, and detection is vital to prevent morbidity and improve quality of life.

Primary oculomotor nerve palsy due to mild head injury. Report of two cases

International Nuclear Information System (INIS)

Katsuno, Makoto; Kobayashi, Shiro; Yokota, Hiroyuki; Teramoto, Akira

2008-01-01

Two patients with primary oculomotor nerve palsy due to direct mild head injury are reported. They presented with internal ophthalmoplegia, dilated nonreactive pupils, and very mild disturbance in consciousness. Except for the persistent oculomotor nerve palsy, both the patients recovered fully within one week. Neither demonstrated a history that was suggestive of a cause for their oculomotor nerve palsy. Initial CT scans demonstrated localized subarachnoid hemorrhage around the brain stem. One of the patients had sustained a fracture of the anterior clinoid process. As the underlying pathophysiologic mechanism underlying the oculomotor nerve palsy we suspected mild injury to the pupillomotor fibers at the anterior petroclinoidal ligament and that of the pupillary fibers at the posterior petroclinoidal ligament. We speculate that these perforating fibers at the anterior petroclinoidal ligament acted as a fulcrum due to downward displacement of the brainstem at the time of impact. (author)

Retinal nerve fiber layer thickness in normals measured by spectral domain OCT.

Science.gov (United States)

Bendschneider, Delia; Tornow, Ralf P; Horn, Folkert K; Laemmer, Robert; Roessler, Christopher W; Juenemann, Anselm G; Kruse, Friedrich E; Mardin, Christian Y

2010-09-01

To determine normal values for peripapillary retinal nerve fiber layer thickness (RNFL) measured by spectral domain Optical Coherence Tomography (SOCT) in healthy white adults and to examine the relationship of RNFL with age, gender, and clinical variables. The peripapillary RNFL of 170 healthy patients (96 males and 74 females, age 20 to 78 y) was imaged with a high-resolution SOCT (Spectralis HRA+OCT, Heidelberg Engineering) in an observational cross-sectional study. RNFL thickness was measured around the optic nerve head using 16 automatically averaged, consecutive circular B-scans with 3.4-mm diameter. The automatically segmented RNFL thickness was divided into 32 segments (11.25 degrees each). One randomly selected eye per subject entered the study. Mean RNFL thickness in the study population was 97.2 ± 9.7 μm. Mean RNFL thickness was significantly negatively correlated with age (r = -0.214, P = 0.005), mean RNFL decrease per decade was 1.90 μm. As age dependency was different in different segments, age-correction of RNFL values was made for all segments separately. Age-adjusted RNFL thickness showed a significant correlation with axial length (r = -0.391, P = 0.001) and with refractive error (r = 0.396, P<0.001), but not with disc size (r = 0.124). Normal RNFL results with SOCT are comparable to those reported with time-domain OCT. In accordance with the literature on other devices, RNFL thickness measured with SOCT was significantly correlated with age and axial length. For creating a normative database of SOCT RNFL values have to be age adjusted.

One-tone suppression in the frog auditory nerve

DEFF Research Database (Denmark)

Christensen-Dalsgaard, J; Jørgensen, M B

1996-01-01

Sixty-seven fibers of a sample of 401 in the auditory nerve of grassfrogs (Rana temporaria) showed one-tone suppression, i.e., their spontaneous activity was suppressed by tones. All fibers were afferents from the amphibian papilla with best frequencies between 100 and 400 Hz. Best suppression...

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.

Expression patterns and role of PTEN in rat peripheral nerve development and injury.

Science.gov (United States)

Chen, Hui; Xiang, Jianping; Wu, Junxia; He, Bo; Lin, Tao; Zhu, Qingtang; Liu, Xiaolin; Zheng, Canbin

2018-05-29

Studies have suggested that phosphatase and tensin homolog (PTEN) plays an important role in neuroprotection and neuronal regeneration. To better understand the potential role of PTEN with respect to peripheral nerve development and injury, we investigated the expression pattern of PTEN at different stages of rat peripheral nerve development and injury and subsequently assessed the effect of pharmacological inhibition of PTEN using bpV(pic) on axonal regeneration in a rat sciatic nerve crush injury model. During the early stages of development, PTEN exhibits low expression in neuronal cell bodies and axons. From embryonic day (E) 18.5 and postnatal day (P)5 to adult, PTEN protein becomes more detectable, with high expression in the dorsal root ganglia (DRG) and axons. PTEN expression is inhibited in peripheral nerves, preceding myelination during neuronal development and remyelination after acute nerve injury. Low PTEN expression after nerve injury promotes Akt/mammalian target of rapamycin (mTOR) signaling pathway activity. In vivo pharmacological inhibition of PTEN using bpV(pic) promoted axonal regrowth, increased the number of myelinated nerve fibers, improved locomotive recovery and enhanced the amplitude response and nerve conduction velocity following stimulation in a rat sciatic nerve crush injury model. Thus, we suggest that PTEN may play potential roles in peripheral nerve development and regeneration and that inhibition of PTEN expression is beneficial for nerve regeneration and functional recovery after peripheral nerve injury. Copyright © 2018 Elsevier B.V. All rights reserved.

Retinal ganglion cell-inner plexiform and nerve fiber layers in neuromyelitis optica

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Sai-Jing Hu

2018-01-01

Full Text Available AIM: To determine the thickness of the retinal ganglion cell-inner plexiform layer (GCIPL and the retinal nerve fiber layer (RNFL in patients with neuromyelitis optica (NMO. METHODS: We conducted a cross-sectional study that included 30 NMO patients with a total of 60 eyes. Based on the presence or absence of optic neuritis (ON, subjects were divided into either the NMO-ON group (30 eyes or the NMO-ON contra group (10 eyes. A detailed ophthalmologic examination was performed for each group; subsequently, the GCIPL and the RNFL were measured using high-definition optical coherence tomography (OCT. RESULTS: In the NMO-ON group, the mean GCIPL thickness was 69.28±21.12 μm, the minimum GCIPL thickness was 66.02±10.02 μm, and the RNFL thickness were 109.33±11.23, 110.47±3.10, 64.92±12.71 and 71.21±50.22 μm in the superior, inferior, temporal and nasal quadrants, respectively. In the NMO-ON contra group, the mean GCIPL thickness was 85.12±17.09 μm, the minimum GCIPL thickness was 25.39±25.1 μm, and the RNFL thicknesses were 148.33±23.22, 126.36±23.45, 82.21±22.30 and 83.36±31.28 μm in the superior, inferior, temporal and nasal quadrants, respectively. In the control group, the mean GCIPL thickness was 86.98±22.37 μm, the minimum GCIPL thickness was 85.28±10.75 μm, and the RNFL thicknesses were 150.22±22.73, 154.79±60.23, 82.33±7.01 and 85.62±13.81 μm in the superior, inferior, temporal and nasal quadrants, respectively. The GCIPL and RNFL were thinner in the NMO-ON contra group than in the control group (P<0.05; additionally, the RNFL was thinner in the inferior quadrant in the NMO-ON group than in the control group (P<0.05. Significant correlations were observed between the GCIPL and RNFL thickness measurements as well as between thickness measurements and the two visual field parameters of mean deviation (MD and corrected pattern standard deviation (PSD in the NMO-ON group (P<0.05. CONCLUSION: The thickness of the GCIPL

An artificial arm/hand system with a haptic sensory function using electric stimulation of peripheral sensory nerve fibers.

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Mabuchi, Kunihiko

2013-01-01

We are currently developing an artificial arm/hand system which is capable of sensing stimuli and then transferring these stimuli to users as somatic sensations. Presently, we are evoking the virtual somatic sensations by electrically stimulating a sensory nerve fiber which innervates a single mechanoreceptor unit at the target area; this is done using a tungsten microelectrode that was percutaneously inserted into the use's peripheral nerve (a microstimulation method). The artificial arm/hand system is composed of a robot hand equipped with a pressure sensor system on its fingers. The sensor system detects mechanical stimuli, which are transferred to the user by means of the microstimulation method so that the user experiences the stimuli as the corresponding somatic sensations. In trials, the system worked satisfactorily and there was a good correlation between the pressure applied to the pressure sensors on the robot fingers and the subjective intensities of the evoked pressure sensations.

Bone marrow-derived mesenchymal stem cells versus adipose-derived mesenchymal stem cells for peripheral nerve regeneration

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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

Influence of corneal power on circumpapillary retinal nerve fiber layer and optic nerve head measurements by spectral-domain optical coherence tomography

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Kazunori Hirasawa

2017-09-01

Full Text Available AIM: To evaluate the influence of corneal power on circumpapillary retinal nerve fiber layer (cpRNFL and optic nerve head (ONH measurements by spectral-domain optical coherence tomography (SD-OCT. METHODS: Twenty-five eyes of 25 healthy participants (mean age 23.6±3.6y were imaged by SD-OCT using horizontal raster scans. Disposable soft contact lenses of different powers (from −11 to +5 diopters including 0 diopter were worn to induce 2-diopter changes in corneal power. Differences in the cpRNFL and ONH measurements per diopter of change in corneal power were analyzed. RESULTS: As corneal power increased by 1 diopter, total and quadrant cpRNFL thicknesses, except for the nasal sector, decreased by −0.19 to −0.32 μm (P<0.01. Furthermore, the disc, cup, and rim areas decreased by −0.017, −0.007, and −0.015 mm2, respectively (P<0.001; the cup and rim volumes decreased by −0.0013 and −0.006 mm3, respectively (P<0.01; and the vertical and horizontal disc diameters decreased by −0.006 and −0.007 mm, respectively (P<0.001. CONCLUSION: For more precise OCT imaging, the ocular magnification should be corrected by considering both the axial length and corneal power. However, the effect of corneal power changes on cpRNFL thickness and ONH topography are small when compare with those of the axial length.

Allograft pretreatment for the repair of sciatic nerve defects: green tea polyphenols versus radiation

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Sheng-hu Zhou

2015-01-01

Full Text Available Pretreatment of nerve allografts by exposure to irradiation or green tea polyphenols can eliminate neuroimmunogenicity, inhibit early immunological rejection, encourage nerve regeneration and functional recovery, improve tissue preservation, and minimize postoperative infection. In the present study, we investigate which intervention achieves better results. We produced a 1.0 cm sciatic nerve defect in rats, and divided the rats into four treatment groups: autograft, fresh nerve allograft, green tea polyphenol-pretreated (1 mg/mL, 4°C nerve allograft, and irradiation-pretreated nerve allograft (26.39 Gy/min for 12 hours; total 19 kGy. The animals were observed, and sciatic nerve electrophysiology, histology, and transmission electron microscopy were carried out at 6 and 12 weeks after grafting. The circumference and structure of the transplanted nerve in rats that received autografts or green tea polyphenol-pretreated nerve allografts were similar to those of the host sciatic nerve. Compared with the groups that received fresh or irradiation-pretreated nerve allografts, motor nerve conduction velocity in the autograft and fresh nerve allograft groups was greater, more neurites grew into the allografts, Schwann cell proliferation was evident, and a large number of new blood vessels was observed; in addition, massive myelinated nerve fibers formed, and abundant microfilaments and microtubules were present in the axoplasm. Our findings indicate that nerve allografts pretreated by green tea polyphenols are equivalent to transplanting autologous nerves in the repair of sciatic nerve defects, and promote nerve regeneration. Pretreatment using green tea polyphenols is better than pretreatment with irradiation

Prevalence of ulnar-to-median nerve motor fiber anastomosis (Riché-Cannieu communicating branch) in hand: An electrophysiological study

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Ahadi, Tannaz; Raissi, Gholam Reza; Yavari, Masood; Majidi, Lobat

2016-01-01

Background: Two main muscles studied in the hand for evaluation of median nerve injuries are opponens pollicis (OP) and abductor pollicis brevis (APB). However, Riché-Cannieu communicating branch (RCCB) may limit the use of these muscles in electrodiagnosis. This condition is confusing in the case of median nerve injuries. This study was conducted to evaluate the prevalence of RCCB. Methods: Twenty-three consecutive cases of complete median nerve injury were studied. Evoked responses via stimulation of median and ulnar nerves in the wrist and recording with needle in the thenar area were studied. Results: Of the patients, 82.6% exhibited RCCB. In 14 (60.8%) cases the OP and in 19(82.6%) cases APB was supplied by the ulnar nerve. Conclusion: RCCB was detected to be 60.8% in OP and 82.6% in APB, so OP is preferable to APB in the study of median nerve. PMID:27390694

Neuro-otological and peripheral nerve involvement in Fabry disease

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Sergio Carmona

2017-07-01

Full Text Available 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 neurootological 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.

Superhydrophobic conductive textiles with antibacterial property by coating fibers with silver nanoparticles

International Nuclear Information System (INIS)

Xue Chaohua; Chen Jia; Yin Wei; Jia Shuntian; Ma Jianzhong

2012-01-01

Silver nanoparticles (Ag NPs) were produced on cotton fibers by reduction of [Ag(NH 3 ) 2 ] + complex with glucose. Further modification of the fibers coated by Ag NPs with hexadecyltrimethoxysilane led to superhydrophobic cotton textiles. Scanning electron microscopy images of the textiles showed that the treated fibers were covered with uniform Ag NPs, which generate a dual-size roughness on the textiles favouring the formation of superhydrophobic surfaces, and the Ag NPs formed dense coating around the fibers rendering the intrinsic insulating cotton textiles conductive. Antibacterial test showed that the as-fabricated textiles had high antibacterial activity against the gram-negative bacteria, Escherichia coli. These multifunctional textiles might find applications in biomedical electronic devices.

DIC imaging for identification of motor and sensory nerves

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Dayu Chen

2016-09-01

Full Text Available Identification of motor and sensory nerves is important in applications such as nerve injury repair. Conventional practice relies on time consuming staining methods for this purpose. Here, we use laser scanning infrared differential interference contrast (IR-DIC microscopy for label-free observation of the two types of nerve. Ventral and dorsal nerve roots of adult beagle dogs were collected and sections of different thicknesses were imaged with an IR-DIC microscope. Different texture patterns of the IR-DIC images of the motor and sensory nerve can be distinguished when the section thickness increases to 40μm. This suggests that nerve fibers in motor and sensory nerves have different distribution patterns. The result hints a potential new way for more rapid identification of nerve type in peripheral nerve repair surgery.

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

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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

Ulnar nerve sonography in leprosy neuropathy.

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Wang, Zhu; Liu, Da-Yue; Lei, Yang-Yang; Yang, Zheng; Wang, Wei

2016-01-01

A 23-year-old woman presented with a half-year history of right forearm sensory and motor dysfunction. Ultrasound imaging revealed definite thickening of the right ulnar nerve trunk and inner epineurium, along with heterogeneous hypoechogenicity and unclear nerve fiber bundle. Color Doppler exhibited a rich blood supply, which was clearly different from the normal ulnar nerve presentation with a scarce blood supply. The patient subsequently underwent needle aspiration of the right ulnar nerve, and histopathological examination confirmed that granulomatous nodules had formed with a large number of infiltrating lymphocytes and a plurality of epithelioid cells in the fibrous connective tissues, with visible atypical foam cells and proliferous vascularization, consistent with leprosy. Our report will familiarize readers with the characteristic sonographic features of the ulnar nerve in leprosy, particularly because of the decreasing incidence of leprosy in recent years.

The conduction block produced by oxcarbazepine in the isolated rat sciatic nerve: a comparison with lamotrigine.

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Guven, Mustafa; Kahraman, Ibrahim; Koc, Filiz; Bozdemir, Hacer; Sarica, Yakup; Gunay, Ismail

2011-01-01

Oxcarbazepine is an antiepileptic drug widely used for the treatment of neuropathic pain. In the present study, the effects of oxcarbazepine and lamotrigine on conduction properties in the rat sciatic nerves were examined. The experiments were conducted with in vitro sucrose-gap technique on the isolated wistar rat sciatic nerves. The compound action potentials were obtained by tonic (single) and phasic (10, 40, and 100 Hz) stimulation. Oxcarbazepine produced a significant concentration- and frequency-dependent reduction in the compound action potential amplitude. When the two drugs were applied at concentrations that produced equal levels of tonic (i.e., non-frequency-dependent) conduction block, oxcarbazepine produced the greatest phasic (i.e., frequency-dependent) conduction block, followed by lamotrigine. Oxcarbazepine and lamotrigine reduced the 4-aminopyridine-induced amplitude of delayed depolarization; however, oxcarbazepine had a significantly greater effect than lamotrigine. These results suggest that oxcarbazepine produces more potent frequency-dependent conduction block than lamotrigine, and suppresses the delayed depolarization which contributes to sensory signaling and may play a role in neuropathic pain. The findings provide insight into the mechanisms of action of oxcarbazepine and lamotrigine and may help in the development of novel therapies for neuropathic pain.

Saltatory conduction in unmyelinated axons: Clustering of Na+ channels on lipid rafts allows micro-saltatory conduction in C-fibers

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Ali eNeishabouri

2014-10-01

Full Text Available The action potential (AP, the fundamental signal of the nervous system, is carried by two types of axons: unmyelinated and myelinated fibers. In the former the action potential propagates continuously along the axon as established in large-diameter fibers. In the latter axons the AP jumps along the Nodes of Ranvier – discrete, anatomically specialized regions which contain very high densities of sodium ion (Na + channels. Therefore saltatory conduction is thought as the hallmark of myelinated axons, which enables faster and more reliable propagation of signals than in unmyelinated axons of same outer diameter.Recent molecular anatomy showed that in C-fibers, the very thin (0.1 μm diameter axons of the peripheral nervous system, Nav1.8 channels are clustered together on lipid rafts that float in the cell membrane. This localized concentration of Na+ channels resembles in structure the ion channel organization at the Nodes of Ranvier, yet it is currently unknown whether this translates into equivalent phenomenon of saltatory conduction or related-functional benefits and efficiencies. Therefore, we modeled biophysically realistic unmyelinated axons with both conventional and lipid-raft based organization of Na+ channels. We find that action potentials are reliably conducted in a micro-saltatory fashion along lipid rafts.Comparing APs in unmyelinated fibers with and without lipid rafts did not reveal any significant difference in either the metabolic cost or AP propagation velocity. By investigating the efficiency of AP propagation over Nav1.8 channels, we find however that the specific inactivation properties of these channels significantly increase the metabolic cost of signaling in C-fibers.

Characterizing the reduction of stimulation artifact noise in a tripolar nerve cuff electrode by application of a conductive shield layer.

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Sabetian, Parisa; Sadeghlo, Bita; Zhang, Chengran Harvey; Yoo, Paul B

2017-02-01

Tripolar nerve cuff electrodes have been widely used for measuring peripheral nerve activity. However, despite the high signal-to-noise ratio levels that can be achieved with this recording configuration, the clinical use of cuff electrodes in closed-loop controlled neuroprostheses remains limited. This is largely attributed to artifact noise signals that contaminate the recorded neural activity. In this study, we investigated the use of a conductive shield layer (CSL) as a means of reducing the artifact noise recorded by nerve cuff electrodes. Using both computational simulations and in vivo experiments, we found that the CSL can result in up to an 85% decrease in the recorded artifact signal. Both the electrical conductivity and the surface area of the CSL were identified as important design criteria. Although this study shows that the CSL can significantly reduce artifact noise in tripolar nerve cuff electrodes, long-term implant studies are needed to validate our findings. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

Enhanced adhesion and proliferation of human umbilical vein endothelial cells on conductive PANI-PCL fiber scaffold by electrical stimulation

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Li, Yumei; Li, Xiang; Zhao, Rui; Wang, Chuying; Qiu, Fangping; Sun, Bolun; Ji, He; Qiu, Ju; Wang, Ce

2017-01-01

Recently, electrically conductive biomaterial scaffolds have shown great potential in tissue regeneration. Herein, we reported an electrically conductive polyaniline (PANI) coated poly(ε-caprolactone) (PCL) electrospun micron-fiber scaffold for the enhanced attachment and proliferation of human umbilical vein endothelial cells (HUVECs) under electrical stimulation conditions. After the O 2 plasma treatment toward PCL electrospun fiber, PANI could be polymerized onto their surfaces successfully. The obtained PANI-PCL fibers were characterized by SEM observations, FT-IR spectra, XPS analysis, and water contact angle measurement. The mechanical tests indicated that the fibers could satisfy the practical vascular scaffold requirements. The conductivity of the PANI-PCL fibers was 6.71 × 10 −3 S/cm which could provide a conductive in-vitro platform to study the effect of electrical stimulation on HUVECs proliferation. When PANI-coated PCL fibers were compared with PCL fibers, HUVECs exhibited highly enhanced adhesion and viability, especially under electrical stimulation (ES) of 200, 300, and 400 mV/cm. Proliferation of HUVECs on PANI-PCL fibers was strongly dependent on electrical stimulation intensity. The results showed new insights into conductive scaffolds for vascular tissue engineering. - Highlights: • Electrospun PCL fibers were subjected to an O 2 plasma treatment to improve the hydrophilicity. • PANI was coated onto the surface of PCL fibers successfully after the plasma treatment. • HUVECs could attach, spread, and survive better on PANI-PCL fibers than on pure PCL fibers. • Electrical stimulation benefited proliferation of HUVECs on conductive PANI-PCL scaffold.

Enhanced adhesion and proliferation of human umbilical vein endothelial cells on conductive PANI-PCL fiber scaffold by electrical stimulation

Energy Technology Data Exchange (ETDEWEB)

Li, Yumei [Alan G. MacDiarmid Institute, Jilin University, Changchun 130012 (China); Department of Clinical Pharmacy and Traditional Chinese Medicine Pharmacology, School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun 130117 (China); Li, Xiang; Zhao, Rui [Alan G. MacDiarmid Institute, Jilin University, Changchun 130012 (China); Wang, Chuying [Department of Clinical Pharmacy and Traditional Chinese Medicine Pharmacology, School of Pharmaceutical Sciences, Changchun University of Chinese Medicine, Changchun 130117 (China); Qiu, Fangping, E-mail: qfp2004@126.com [Chemistry and Biology Science College, Changchun University of Technology, Changchun 130012 (China); Sun, Bolun; Ji, He; Qiu, Ju [Alan G. MacDiarmid Institute, Jilin University, Changchun 130012 (China); Wang, Ce, E-mail: cwang@jlu.edu.cn [Alan G. MacDiarmid Institute, Jilin University, Changchun 130012 (China)

2017-03-01

Recently, electrically conductive biomaterial scaffolds have shown great potential in tissue regeneration. Herein, we reported an electrically conductive polyaniline (PANI) coated poly(ε-caprolactone) (PCL) electrospun micron-fiber scaffold for the enhanced attachment and proliferation of human umbilical vein endothelial cells (HUVECs) under electrical stimulation conditions. After the O{sub 2} plasma treatment toward PCL electrospun fiber, PANI could be polymerized onto their surfaces successfully. The obtained PANI-PCL fibers were characterized by SEM observations, FT-IR spectra, XPS analysis, and water contact angle measurement. The mechanical tests indicated that the fibers could satisfy the practical vascular scaffold requirements. The conductivity of the PANI-PCL fibers was 6.71 × 10{sup −3} S/cm which could provide a conductive in-vitro platform to study the effect of electrical stimulation on HUVECs proliferation. When PANI-coated PCL fibers were compared with PCL fibers, HUVECs exhibited highly enhanced adhesion and viability, especially under electrical stimulation (ES) of 200, 300, and 400 mV/cm. Proliferation of HUVECs on PANI-PCL fibers was strongly dependent on electrical stimulation intensity. The results showed new insights into conductive scaffolds for vascular tissue engineering. - Highlights: • Electrospun PCL fibers were subjected to an O{sub 2} plasma treatment to improve the hydrophilicity. • PANI was coated onto the surface of PCL fibers successfully after the plasma treatment. • HUVECs could attach, spread, and survive better on PANI-PCL fibers than on pure PCL fibers. • Electrical stimulation benefited proliferation of HUVECs on conductive PANI-PCL scaffold.

Análise da camada de fibras nervosas da retina em usuários crônicos do tabaco e álcool Analysis of retinal nerve fiber layer in chronic tobacco and alcohol users

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Rita de Cássia Ramos de Lima

2006-06-01

Full Text Available OBJETIVOS: Avaliar a camada de fibras nervosas (CFN da retina, através da polarimetria a laser (GDx, em usuários crônicos do tabaco e álcool. MÉTODOS: Foram estudados 46 olhos de 23 indivíduos alcoólatras e tabagistas crônicos triados do Ambulatório de Oftalmologia da Fundação Altino Ventura (grupo estudo. Como grupo controle foram incluídos 32 olhos de 16 voluntários não-usuários do álcool e tabaco, com idade, gênero e raça similares, também triados da Fundação Altino Ventura. Ambos os olhos de todos os indivíduos foram submetidos à análise da camada de fibras nervosas da retina, com aparelho "GDx nerve fiber analyses" pelo mesmo examinador. RESULTADOS: No gráfico Deviation from normal, no grupo estudo ocorreu perda de fibras nervosas da retina em 43,4%, enquanto que no grupo controle houve perda apenas em 18,7%. Quanto aos parâmetros que analisam o GDx, quando comparados o grupo estudo com o grupo controle, observou-se diferença estatisticamente significante nos parâmetros: Ellipse modulation, Inferior ratio e Max modulation. CONCLUSÕES: Os dados comprovam a associação entre o uso crônico do tabaco e álcool e a alteração na camada de fibras nervosas da retina, podendo contribuir para o diagnóstico precoce desta neuropatia.PURPOSES: To evaluate the retinal nerve fiber layer using GDx in chronic alcohol and tobacco users. METHODS: Twenty-three chronic alcohol and tobacco users were studied (study group. As a control group, sixteen volunteers without use of alcohol and tobacco with similar characteristics (age, gender and race were included. Both eyes were tested for analysis of the retinal nerve fiber layer with GDx. RESULTS: There was alteration in the Deviation from normal graph with a loss of nerve fibers in 43.4% of patients in the study group. In the control group this alteration was observed in 14 eyes (18.7%. As regards the parameters that allow comparison between the study and control groups there was

Label-free photoacoustic microscopy of peripheral nerves

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Matthews, Thomas Paul; Zhang, Chi; Yao, Da-Kang; Maslov, Konstantin; Wang, Lihong V.

2014-01-01

Peripheral neuropathy is a common neurological problem that affects millions of people worldwide. Diagnosis and treatment of this condition are often hindered by the difficulties in making objective, noninvasive measurements of nerve fibers. Photoacoustic microscopy (PAM) has the ability to obtain high resolution, specific images of peripheral nerves without exogenous contrast. We demonstrated the first proof-of-concept imaging of peripheral nerves using PAM. As validated by both standard histology and photoacoustic spectroscopy, the origin of photoacoustic signals is myelin, the primary source of lipids in the nerves. An extracted sciatic nerve sandwiched between two layers of chicken tissue was imaged by PAM to mimic the in vivo case. Ordered fibrous structures inside the nerve, caused by the bundles of myelin-coated axons, could be observed clearly. With further technical improvements, PAM can potentially be applied to monitor and diagnose peripheral neuropathies.

[Effect of deep electroacupuncture stimulation of "Huantiao" (GB 30) on changes of function and nerve growth factor expression of the injured sciatic nerve in rats].

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Liu, Yu-Li; Li, Ye; Ren, Lu; Dai, Li-Li; Bai, Zeng-Hua; Bai, Ru; Ma, Tie-Ming

2014-04-01

OBJECTIVE; To observe the effect of deep electroacupuncture (EA) stimulation of "Huantiao"(GB 30) on the functional and pathological changes and nerve growth factor (NGF) expression of the damaged sciatic nerve in rats, so as to study its mechanisms underlying reliving sciatica. Forty-eight SD rats were randomly divided into normal, model, deep EA and shallow EA groups (n = 12 in each group). The sciatic nerve injury model was established by mechanical clamp of the sciatic nerve stem. For deep and shallow EA, the acupuncture needles were inserted into GB 30 about 16 mm and 7 mm, respectively. The EA treatment was given 20 min, once daily for 14 days. The evoked potentials of the injured sciatic nerve stem responding to electrical stimulation were recorded by using a biophysiological experimental system for calculating the motor conduction velocity. Pathological changes of the sciatic nerve were displayed by H. E. stain. The expression of NGF and Fos proteins was detected by immunohistochemistry. In comparison with the normal group, the conduction velocity and the amplitude of the evoked potentials of the sciatic nerve were significantly decreased in the model group (P 0.05), and no significant changes of latencies of the evoked potentials inthe four groups (P > 0.05). In the model group, the disorganized nerve fibers axons, myelin and Schwann cells of the damaged sciatic nerve were found, which became milder in the EA groups particularly in the deep EA group. In regard to the NGF and Fos immunoactivity of the injured sciatic nerve, the expression levels of both NGF and Fos proteins were obviously higher in the model group than in the normal group (P stimulation, NGF expression was further significantly up-regulated in both deep and shallow EA groups (P stimulation of GB 30 can improve the pathological changes and function of the injured sciatic nerve in the rat, which is closely associated with its effects in up-regulating NGF expression and down-regulating Fos

Correlation between peripapillary retinal nerve fiber layer thickness and fundus autofluorescence in primary open-angle glaucoma

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Reznicek L

2013-09-01

Full Text Available Lukas Reznicek,* Florian Seidensticker,* Thomas Mann, Irene Hübert, Alexandra Buerger, Christos Haritoglou, Aljoscha S Neubauer, Anselm Kampik, Christoph Hirneiss, Marcus Kernt Department of Ophthalmology, Ludwig-Maximilians-University, Munich, Germany *These authors contributed equally to this work Purpose: To investigate the relationship between retinal nerve fiber layer (RNFL thickness and retinal pigment epithelium alterations in patients with advanced glaucomatous visual field defects. Methods: A consecutive, prospective series of 82 study eyes with primary open-angle glaucoma and advanced glaucomatous visual field defects were included in this study. All study participants underwent a full ophthalmic examination followed by visual field testing with standard automated perimetry as well as spectral-domain optical coherence tomography (SD-OCT for peripapillary RNFL thickness and Optos wide-field fundus autofluorescence (FAF images. A pattern grid with corresponding locations between functional visual field sectors and structural peripapillary RNFL thickness was aligned to the FAF images at corresponding location. Mean FAF intensity (range: 0 = black and 255 = white of each evaluated sector (superotemporal, temporal, inferotemporal, inferonasal, nasal, superonasal was correlated with the corresponding peripapillary RNFL thickness obtained with SD-OCT. Results: Correlation analyses between sectoral RNFL thickness and standardized FAF intensity in the corresponding topographic retina segments revealed partly significant correlations with correlation coefficients ranging between 0.004 and 0.376 and were statistically significant in the temporal inferior central field (r = 0.324, P = 0.036 and the nasal field (r = 0.376, P = 0.014. Conclusion: Retinal pigment epithelium abnormalities correlate with corresponding peripapillary RNFL damage, especially in the temporal inferior sector of patients with advanced glaucomatous visual field defects. A

Characterization of nerve and microvessel damage and recovery in type 1 diabetic mice after permanent femoral artery ligation.

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Lozeron, Pierre; Mantsounga, Chris S; Broqueres-You, Dong; Dohan, Anthony; Polivka, Marc; Deroide, Nicolas; Silvestre, Jean-Sébastien; Kubis, Nathalie; Lévy, Bernard I

2015-09-01

Neuropathy is the most common complication of the peripheral nervous system during the progression of diabetes. The pathophysiology is unclear but may involve microangiopathy, reduced endoneurial blood flow, and tissue ischemia. We used a mouse model of type 1 diabetes to study parallel alterations of nerves and microvessels following tissue ischemia. We designed an easily reproducible model of ischemic neuropathy induced by irreversible ligation of the femoral artery. We studied the evolution of behavioral function, epineurial and endoneurial vessel impairment, and large nerve myelinated fiber as well as small cutaneous unmyelinated fiber impairment for 1 month following the onset of ischemia. We observed a more severe hindlimb dysfunction and delayed recovery in diabetic animals. This was associated with reduced density of large arteries in the hindlimb and reduced sciatic nerve epineurial blood flow. A reduction in sciatic nerve endoneurial capillary density was also observed, associated with a reduction in small unmyelinated epidermal fiber number and large myelinated sciatic nerve fiber dysfunction. Moreover, vascular recovery was delayed, and nerve dysfunction was still present in diabetic animals at day 28. This easily reproducible model provides clear insight into the evolution over time of the impact of ischemia on nerve and microvessel homeostasis in the setting of diabetes. © 2015 Wiley Periodicals, Inc. © 2015 Wiley Periodicals, Inc.

History of electromyography and nerve conduction studies: A tribute to the founding fathers.

Science.gov (United States)

Kazamel, Mohamed; Warren, Paula Province

2017-09-01

The early development of nerve conduction studies (NCS) and electromyography (EMG) was linked to the discovery of electricity. This relationship had been concluded by observing the effect of applying electricity to the body of an animal and discovering that nerves and muscles themselves could produce electricity. We attempt to review the historical evolution of NCS and EMG over the last three centuries by reviewing the landmark publications of Galvani, Adrian, Denny-Brown, Larrabee, and Lambert. In 1771, Galvani showed that electrical stimulation of animal muscle tissue produced contraction and, thereby, the concept of animal electricity was born. In 1929, Adrian devised a method to record a single motor unit potential by connecting concentric needle electrodes to an amplifier and a loud speaker. In 1938, Denny-Brown described the fasciculation potentials and separated them from fibrillations. Toward the end of World War II, Larrabee began measuring the compound muscle action potential in healthy and injured nerves of war victims. In 1957, Lambert and Eaton described the electrophysiologic features of a new myasthenic syndrome associated with lung carcinoma. Overall, research on this topic was previously undertaken by neurophysiologists and then later by neurologists, with Adrian most likely being the first neurologist to be involved. The field greatly benefited from the invention of equipment that was capable of amplifying small bioelectrical currents by the beginning of the 20th century. Significant scientific and technical advances were later made during and after World War II which provided a large patient population with nerve injuries to study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Identification and prediction of diabetic sensorimotor polyneuropathy using individual and simple combinations of nerve conduction study parameters.

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Alanna Weisman

Full Text Available OBJECTIVE: Evaluation of diabetic sensorimotor polyneuropathy (DSP is hindered by the need for complex nerve conduction study (NCS protocols and lack of predictive biomarkers. We aimed to determine the performance of single and simple combinations of NCS parameters for identification and future prediction of DSP. MATERIALS AND METHODS: 406 participants (61 with type 1 diabetes and 345 with type 2 diabetes with a broad spectrum of neuropathy, from none to severe, underwent NCS to determine presence or absence of DSP for cross-sectional (concurrent validity analysis. The 109 participants without baseline DSP were re-evaluated for its future onset (predictive validity. Performance of NCS parameters was compared by area under the receiver operating characteristic curve (AROC. RESULTS: At baseline there were 246 (60% Prevalent Cases. After 3.9 years mean follow-up, 25 (23% of the 109 Prevalent Controls that were followed became Incident DSP Cases. Threshold values for peroneal conduction velocity and sural amplitude potential best identified Prevalent Cases (AROC 0.90 and 0.83, sensitivity 80 and 83%, specificity 89 and 72%, respectively. Baseline tibial F-wave latency, peroneal conduction velocity and the sum of three lower limb nerve conduction velocities (sural, peroneal, and tibial best predicted 4-year incidence (AROC 0.79, 0.79, and 0.85; sensitivity 79, 70, and 81%; specificity 63, 74 and 77%, respectively. DISCUSSION: Individual NCS parameters or their simple combinations are valid measures for identification and future prediction of DSP. Further research into the predictive roles of tibial F-wave latencies, peroneal conduction velocity, and sum of conduction velocities as markers of incipient nerve injury is needed to risk-stratify individuals for clinical and research protocols.

[The speed of nerve-conduction after micro-surgical suture of the tibial nerve of the rabbit (author's transl)].

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Weigert, M; Mellerowicz, H; Werhahn, C

1975-10-01

Isolated division of the tibial nerve in the thigh preserving the peroneal and sural nerves does not cause loss of normal position of the animal, in particular of sitting. Nor does it lead to pressure sores. The animals are fitter then after division of the sciatic nerve. Microsurgical suture of the isolated tibial nerve in the thigh of the rabbit with 1 or 2 simple sutures with 10 x 0 thread show that an average recovery can be achieved in over 80 per cent. As few sutures as possible should be used. Otherwise there with be scarring and no return of function.

A new study on diffusion tensor imaging of the whole visual pathway fiber bundle and clinical application

Institute of Scientific and Technical Information of China (English)

TAO Xiao-feng; WANG Zhong-qiu; GONG Wan-qing; JIANG Qing-jun; SHI Zeng-ru

2009-01-01

Background With conventional imaging methods only the morphous of the visual nerve fiber bundles can be demonstrated, while the earlier period functional changes can not be demonstrated. We hypothesized that diffusion tensor imaging (DTI) would demonstrated the whole optic never fiber bundle and visual pathway and the earlier period functional changes. The purpose of the present study was to evaluate the application of DTI technique in the demonstration of the whole optic never fiber bundle and visual pathway, and the influence of orbital tumors on them. Methods GE 1.5T signa HD MR System, and the software package DTV2 were adopted. The total 45 subjects were enrolled, including 15 volunteers and 30 patients. All patients had ocular proptosis from minor to major. Seven patients had visual acuity decrescence. Results The nerve fiber bundles, e.g. optic chiasma, optic tract and optic radiation in posterior visual pathway were well demonstrated in all cases. Wherein, the intact whole visual pathway fiber bundles were clearly revealed in 10 volunteers and 17 patients, and optic nerve was not wholly revealed in the rest of the subjects. Shift of optic nerve caused by compression and partial deformation were seen in 7 patients with orbital tumor. In 6 of 7 patients, DTI displayed significant abscise and deformation of visual nerve. Chi-square test indicated significant correlation between visual acuity decrescence and DTI visual nerve non-display. Conclusions Visual nerve fiber bundles and the whole visual pathway were visualized in most of patients with DTI. It might be an effective method of providing imaging evidence for visual nerve fiber earlier period functional changes, and laid a foundation for the study in other cranial nerves.

Sensory nerve action potentials and sensory perception in women with arthritis of the hand.

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Calder, Kristina M; Martin, Alison; Lydiate, Jessica; MacDermid, Joy C; Galea, Victoria; MacIntyre, Norma J

2012-05-10

Arthritis of the hand can limit a person's ability to perform daily activities. Whether or not sensory deficits contribute to the disability in this population remains unknown. The primary purpose of this study was to determine if women with osteoarthritis (OA) or rheumatoid arthritis (RA) of the hand have sensory impairments. Sensory function in the dominant hand of women with hand OA or RA and healthy women was evaluated by measuring sensory nerve action potentials (SNAPs) from the median, ulnar and radial nerves, sensory mapping (SM), and vibratory and current perception thresholds (VPT and CPT, respectively) of the second and fifth digits. All SNAP amplitudes were significantly lower for the hand OA and hand RA groups compared with the healthy group (p sensory fibers in the median, ulnar and radial nerves. Less apparent were losses in conduction speed or sensory perception.

Microanatomical and immunohistochemical study of the human lateral antebrachial cutaneous nerve of forearm at the antecubital fossa and its clinical implications.

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Marx, S Chakravarthy; Kumar, Pramod; Dhalapathy, S; Prasad, Keerthana; Marx, C Anitha

2010-09-01

Changes in the intraneural anatomy with age can cause poor prognosis of nerve repair in patients after nerve injury. The occurrence of Complex Regional Pain Syndrome-Type II, secondary to peripheral nerve injury, is common. The purpose of this study is to asses changes in cross-sectional anatomy of the lateral antebrachial cutaneous nerve of forearm (LCNF) at the antecubital fossa in the fascicular, nonfascicular components (adipose and nonadipose tissue), and sympathetic fibers area with respect to age. For the purpose of the study, 32 human (37-88 years) fresh cadaveric LCNF were collected from left-antecubital fossae and processed for histological, morphometric analysis [total cross-sectional (Asc), fascicular (Af), and nonfascicular area (Anonf)], and immunohistochemical method (tyrosine hydroxylase) for sympathetic fibers. The LCNF's average total cross-sectional area was 3.024 mm(2), and fascicular area was 0.582 mm(2). The average number of fascicles per mm(2) was 3.09. The cross-sectional area in the nerve was mainly occupied by nonfascicular connective tissue (80.75%). There was increased adipose tissue deposition (48.48% of Asc) and decreased collagen fibers (32.24% of Asc) in interfascicular domains without any definite relationship with age. The average sympathetic fiber area was 0.026 mm(2) within the nerve fascicular area without any correlation with age. In LCNF, there was more adipose tissue and less collagen fibers deposition in the interfascicular domains of all age cases, and this may act as an obstacle for nerve fiber regeneration on using LCNF as an interpositional nerve graft.

Fiber Sensor Technology Today

Science.gov (United States)

Hotate, Kazuo

2006-08-01

Fiber sensor technologies are overviewed. Since the early 1970s, this field has been developed, on the basis of the same devices and photonic principles as fiber communication technologies. Besides simple configurations, in which the fiber acts only as a data transmission line, sophisticated configurations have also been developed, in which the fiber is used as a device to realize unique sensing mechanisms. The fiber optic gyroscope (FOG) is a good example, and has been developed as an absolute rotation sensor used, for example, for navigation and/or attitude control applications. Compared with traditional spinning-mass gyroscopes, the FOG has advantages, such as a short warming-up time, a light weight, and easy handling. A Japanese satellite, which was launched in August 2005 with a mission to observe the aurora, is controlled with a FOG. The FOG has also been used in consumer applications, such as the camera stabilizer, radio-controlled (RC) helicopter navigation, and the control of humanoid robots. Recently, distributed and multiplexed sensing schemes, in particular, have been studied and developed, in which a long fiber acts like a “nerve” for feeling the strain and/or the temperature distribution along the fiber. Performances of artificial nerve systems have markedly improved within the last couple of years, in spatial resolution and measurement speed. By embedding the “fiber-optic nerve system” in aircraft wings, bridges and tall buildings, these materials and structures can sense damage to prevent disasters.

A review of nerve conduction studies in cases of suspected compression neuropathies of the upper limb.

LENUS (Irish Health Repository)

Neligan, A

2010-01-01

Entrapment neuropathies, particularly those affecting upper limbs, are common reasons for referral for nerve conduction studies (NCS). However, concordance between clinical findings and NCS findings, especially in patients being considered for intervention including decompressive surgery, has not been assessed.

Loss of Sympathetic Nerves in Spleens from Patients with End Stage Sepsis

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Donald B. Hoover

2017-12-01

Full Text Available The spleen is an important site for central regulation of immune function by noradrenergic sympathetic nerves, but little is known about this major region of neuroimmune communication in humans. Experimental studies using animal models have established that sympathetic innervation of the spleen is essential for cholinergic anti-inflammatory responses evoked by vagal nerve stimulation, and clinical studies are evaluating this approach for treating inflammatory diseases. Most data on sympathetic nerves in spleen derive from rodent studies, and this work has established that remodeling of sympathetic innervation can occur during inflammation. However, little is known about the effects of sepsis on spleen innervation. Our primary goals were to (i localize noradrenergic nerves in human spleen by immunohistochemistry for tyrosine hydroxylase (TH, a specific noradrenergic marker, (ii determine if nerves occur in close apposition to leukocytes, and (iii determine if splenic sympathetic innervation is altered in patients who died from end stage sepsis. Staining for vesicular acetylcholine transporter (VAChT was done to screen for cholinergic nerves. Archived paraffin tissue blocks were used. Control samples were obtained from trauma patients or patients who died after hemorrhagic stroke. TH + nerves were associated with arteries and arterioles in all control spleens, occurring in bundles or as nerve fibers. Individual TH + nerve fibers entered the perivascular region where some appeared in close apposition to leukocytes. In marked contrast, spleens from half of the septic patients lacked TH + nerves fibers and the average abundance of TH + nerves for the septic group was only 16% of that for the control group (control: 0.272 ± 0.060% area, n = 6; sepsis: 0.043 ± 0.026% area, n = 8; P < 0.005. All spleens lacked cholinergic innervation. Our results provide definitive evidence for the distribution of noradrenergic

Antibody Immobilization on Conductive Polymer Coated Nonwoven Fibers for Biosensors

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Shannon K. MCGRAW

2011-12-01

Full Text Available This work is being performed to develop rapid and novel electrochemical biosensors for foodborne pathogen detection. This research focuses on electrotextile platforms to perform both capture and sensing functions in a single component. The biosensor uses nonwoven fiber membranes coated with conductive polymer and functionalized with antibodies for biological capture. This study examines three methods for antibody immobilization: passive adsorption, glutaraldehyde cross-linking, and EDC/Sulfo-NHS cross-linking. Antibodies are immobilized onto the conductive fiber surfaces for the specific capture of a target pathogen. The immobilization and capture capabilities of each method are analyzed through the use of two different fluorescent reporters: FITC and PicoGreen DNA stain. Fluorescence is measured using a fluorescent plate reader and then imaged using a fluorescent microscope. The effect of a blocking agent on specificity is also evaluated. It is found that glutaraldehyde with blocking is the best immobilization method with PicoGreen being the best fluorescent reporter.

Bilateral absence of musculocutaneous nerve

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Mathada V Ravishankar

2012-01-01

Full Text Available Brachial plexus is an important group of spinal nerve plexus that supplies the muscles of the upper limb via the ventral rami of the Cervical 5 - Thoracic 1 fibers of the spinal nerves. It is not uncommon to notice the variations during cadaveric dissections in many regions of the body, at different levels, such as, roots, trunks, division, cords, communications, and branches as reported in the literature. Although the nerve supply of the body musculature takes place in the fetal life itself, its course, branching pattern, innervations, and communication can show variable patterns as the fetal development progresses. One such anomaly was noticed during our routine cadaveric dissection in the Department of Anatomy, Jawaharlal Nehru Medical College, Belgaum, showing bilateral absence of the musculocutaneous nerve, which obviously drew the attention of the students of medicine, physiotherapy, and learning clinicians as well.

Optical stimulation of the facial nerve: a surgical tool?

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Richter, Claus-Peter; Teudt, Ingo Ulrik; Nevel, Adam E.; Izzo, Agnella D.; Walsh, Joseph T., Jr.

2008-02-01

One sequela of skull base surgery is the iatrogenic damage to cranial nerves. Devices that stimulate nerves with electric current can assist in the nerve identification. Contemporary devices have two main limitations: (1) the physical contact of the stimulating electrode and (2) the spread of the current through the tissue. In contrast to electrical stimulation, pulsed infrared optical radiation can be used to safely and selectively stimulate neural tissue. Stimulation and screening of the nerve is possible without making physical contact. The gerbil facial nerve was irradiated with 250-μs-long pulses of 2.12 μm radiation delivered via a 600-μm-diameter optical fiber at a repetition rate of 2 Hz. Muscle action potentials were recorded with intradermal electrodes. Nerve samples were examined for possible tissue damage. Eight facial nerves were stimulated with radiant exposures between 0.71-1.77 J/cm2, resulting in compound muscle action potentials (CmAPs) that were simultaneously measured at the m. orbicularis oculi, m. levator nasolabialis, and m. orbicularis oris. Resulting CmAP amplitudes were 0.3-0.4 mV, 0.15-1.4 mV and 0.3-2.3 mV, respectively, depending on the radial location of the optical fiber and the radiant exposure. Individual nerve branches were also stimulated, resulting in CmAP amplitudes between 0.2 and 1.6 mV. Histology revealed tissue damage at radiant exposures of 2.2 J/cm2, but no apparent damage at radiant exposures of 2.0 J/cm2.

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

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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

Analysis of temperature distribution in a heat conducting fiber with ...

African Journals Online (AJOL)

The temperature distribution in a heat conducting fiber is computed using the Galerkin Finite Element Method in the present study. The weak form of the governing differential equation is obtained and nodal temperatures for linear and quadratic interpolation functions for different mesh densities are calculated for Neumann ...

Surface microstructures on planar substrates and textile fibers guide neurite outgrowth: a scaffold solution to push limits of critical nerve defect regeneration?

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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.

Regeneration of peripheral nerve fibres following Haloxon-induced degeneration

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Maria Veronica de Souza

1996-12-01

Full Text Available Delayed neurotoxicity has been associated with organophosphorus poisoning for years. In order to study such condition in sheep, 11 animals were given either one or two high doses of Haloxon. Exposed sheep were observed daily and between 16 and 25 days after administration neurological signs as incoordination and ataxia were detected in six of them. Biopsies of tibial and laryngeal nerves were performed as soon as neurotoxicity was diagnosed, and after death fragments of selected nerves were collected together with CNS tissues for light and electron microscopy and teased fiber studies. Laryngeal, tibial and sciatic nerves showed the most pronouced changes, consisting chiefly of wallerian degeneration that was seen either as a single fiber or as a complete fascicle feature. Exams performed after death clearly showed regenerating fascicles with axonal sprouts growing within a Schwann cell old basal lamina, and some thinly myelinated axonal sprouts.

Nerve conduction and antioxidant levels in experimentally diabetic rats: effects of streptozotocin dose and diabetes duration

NARCIS (Netherlands)

Gispen, W.H.; Dam, P.S. van; Asbeck, B.S. van; Bravenboer, B.; Oirschot, J.F.L.M. van; Marx, J.J.

1999-01-01

Oxidative stress supposedly plays a role in the pathogenesis of diabetic neuropathy. We have studied whether a variation in the streptozotocin (STZ) dose or diabetes duration affects the outcome of measurements of oxidative damage in relation to nerve conduction. In experiment 1, we induced diabetes

Contribución de fibras mielínicas provenientes de los nervios espinales lumbares L4, L5 y L6 al nervio ciático de rata adulta y sus ramas principales Contribution of myelunated fibers from spinal L4, L5 and L6 nerves to the sciatic nerve and its main branches in the adult rat

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Hernán Hurtado

2000-04-01

Full Text Available El nervio ciático de la rata está formado por los nervios espinales (ne lumbares L4, L5 y L6. Sin embargo, aún no se ha definido el aporte en fibras mielínicas de estos nervios espinales a lo largo del tronco nervioso. En este estudio se transectaron selectivamente los NE L4, L5 y L4-L5. Luego de una semana se disecaron los nervios ciático, tibial, sural y peroneal. Estas muestras se fijaron y procesaron para microscopía óptica y a partir de cortes coloreados con azul de toluidina se contaron las fibras mielínicas degeneradas y normales. L4 contribuyó con fibras mielínicas principalmente al nervio peroneal y L5 a los nervios ciático, tibial y sural. En general, el aporte de L6 fue menor y variable a lo largo del tronco nervioso comparado con las otras dos ramas espinales. Nuestros resultados brindan información valiosa para posteriores estudios que busquen correlacionar la contribución de los nervios espinales que componen el ciático y sus ramas principales con la función de la extremidad inferior. The rat sciatic nerve is composed by the L4, L5 and L6 lumbar spinal nerves. However, the contribution in myelinated fibers originating from these nerves along this nervous trunk has not yet been defined. In the present study, the L4, L5 and L4-L5 spinal nerves were selectively transected. After one week the sciatic, tibial, sural and peroneal nerves were dissected. These samples were fixed and processed for optical microscopy, and both degenerated and normal myelinated fibers were counted in toluidine blue-stained semi-thin sections. L4 contributed with myelinated fibers mainly to the peroneal nerve, and L5 to the sciatic, tibial and sural nerves. In general, the contribution of L6 was smaller and variable along the nervous trunk in comparison to the other two spinal branches. Our results give key information for further studies looking to correlate the contribution of spinal nerves making part of the sciatic nerve and its main

Superficial or deep implantation of motor nerve after denervation: an experimental study--superficial or deep implantation of motor nerve.

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Askar, Ibrahím; Sabuncuoglu, Bízden Tavíl

2002-01-01

manner in both experimental groups. However, they were more dense in the superficial implantation group than the deep implantation group. It was concluded that superficial implantation has a more powerful contractile capacity than that of deep implantation. We believe that this might arise from the high activity of glycolytic enzymes in peripheral muscle fibers of gastrocnemius muscle, decrease in insufficient intramuscular guidance apparatus, and intramuscular microneuroma formation at the insufficient neuromuscular junction since the motor nerve had less route to muscle fibers. Copyright 2002 Wiley-Liss, Inc.

Age, ocular magnification, and circumpapillary retinal nerve fiber layer thickness

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Wang, Mengyu; Elze, Tobias; Li, Dian; Baniasadi, Neda; Wirkner, Kerstin; Kirsten, Toralf; Thiery, Joachim; Loeffler, Markus; Engel, Christoph; Rauscher, Franziska G.

2017-12-01

Optical coherence tomography (OCT) manufacturers graphically present circumpapillary retinal nerve fiber layer thickness (cpRNFLT) together with normative limits to support clinicians in diagnosing ophthalmic diseases. The impact of age on cpRNFLT is typically implemented by linear models. cpRNFLT is strongly location-specific, whereas previously published norms are typically restricted to coarse sectors and based on small populations. Furthermore, OCT devices neglect impacts of lens or eye size on the diameter of the cpRNFLT scan circle so that the diameter substantially varies over different eyes. We investigate the impact of age and scan diameter reported by Spectralis spectral-domain OCT on cpRNFLT in 5646 subjects with healthy eyes. We provide cpRNFLT by age and diameter at 768 angular locations. Age/diameter were significantly related to cpRNFLT on 89%/92% of the circle, respectively (pointwise linear regression), and to shifts in cpRNFLT peak locations. For subjects from age 42.1 onward but not below, increasing age significantly decreased scan diameter (r=-0.28, p<0.001), which suggests that pathological cpRNFLT thinning over time may be underestimated in elderly compared to younger subjects, as scan diameter decrease correlated with cpRNFLT increase. Our detailed numerical results may help to generate various correction models to improve diagnosing and monitoring optic neuropathies.

Recovery of slowed nerve conduction velocity in lead-exposed workers

Energy Technology Data Exchange (ETDEWEB)

Araki, S.; Honma, T.; Yanagihara, S.; Ushio, K.

1980-06-01

Maximum motor nerve conduction velocities in the median nerve (MCV) and blood lead (PbB) were repeatedly measured in 14 lead-exposed workers with an initial PbB from 0.7 to 4.0 ..mu..mol/kg (median 2.3 ..mu..mol/kg) for a period from 3 months to 7 years: A certain dose of Calcium Disodium Ethylenediaminetetraacetic Acid (CaEDTA) was injected intravenously into most of the subjects during the period. In seven subjects, MCV improved by more than 4 m/s during the observation period which involved the first two successive measurements of MCV and PbB, but the remaining seven subjects showed the minimal alteration (within +- 4.0 m/s). The initial value of MCV was significantly slower (P < 0.01) and the decrease in PbB was significantly greater (P < 0.05) in the group of subjects having shown the improvement of MCV by more than 4 m/s. The initial value of MCV was significant in determining the alteration in MCV in multiple regression analysis and, together with the change in PbB, explained 31% of the alteration in MCV between the first two successive measurements. The initial level of PbB, dose of CaEDTA, time interval between the measurements and age played no essential part in the alteration in MCV. The alteration in MCV throughout the whole observational period in each subject significantly correlated with the concurrent change in PbB (r = -0.573, P < 0.001).

Towards seamlessly-integrated textile electronics: methods to coat fabrics and fibers with conducting polymers for electronic applications.

Science.gov (United States)

Allison, Linden; Hoxie, Steven; Andrew, Trisha L

2017-06-29

Traditional textile materials can be transformed into functional electronic components upon being dyed or coated with films of intrinsically conducting polymers, such as poly(aniline), poly(pyrrole) and poly(3,4-ethylenedioxythiophene). A variety of textile electronic devices are built from the conductive fibers and fabrics thus obtained, including: physiochemical sensors, thermoelectric fibers/fabrics, heated garments, artificial muscles and textile supercapacitors. In all these cases, electrical performance and device ruggedness is determined by the morphology of the conducting polymer active layer on the fiber or fabric substrate. Tremendous variation in active layer morphology can be observed with different coating or dyeing conditions. Here, we summarize various methods used to create fiber- and fabric-based devices and highlight the influence of the coating method on active layer morphology and device stability.

Representation of acoustic signals in the eighth nerve of the Tokay gecko: I. Pure tones.

Science.gov (United States)

Sams-Dodd, F; Capranica, R R

1994-06-01

A systematic study of the encoding properties of 146 auditory nerve fibers in the Tokay gecko (Gekko gecko, L) was conducted with respect to pure tones and two-tone rate suppression. Our aim was a comprehensive understanding of the peripheral encoding of simple tonal stimuli and their representation by temporal synchronization and spike rate codes as a prelude to subsequent studies of more complex signals. Auditory nerve fibers in the Tokay gecko have asymmetrical, V-shaped excitatory tuning curves with best excitatory frequencies that range from 200-5100 Hz and thresholds between 4-35 dB SPL. A low-frequency excitatory 'tail' extends far into the low-frequency range and two-tone suppression is present only on the high frequency side of the tuning curve. The response properties to pure tones at different loci within a tuning curve can differ greatly, due to evident interactions between the representations of temporal, spectral and intensity stimulus features. For frequencies below 1250 Hz, pure tones are encoded by both temporal synchronization and spike rate codes, whereas above this frequency a fiber's ability to encode the waveform periodicity is lost and only a rate code predominates. These complimentary representations within a tuning curve raise fundamental issues which need to be addressed in interpreting how more complex, bioacoustic communication signals are represented in the peripheral and central auditory system. And since auditory nerve fibers in the Tokay gecko exhibit tonal sensitivity, selective frequency tuning, and iso-intensity and iso-frequency contours that seem comparable to similar measures in birds and mammals, these issues likely apply to most higher vertebrates in general. The simpler wiring diagram of the reptilian auditory system, coupled with the Tokay gecko's remarkable vocalizations, make this animal a good evolutionary model in which to experimentally explore the encoding of more complex sounds of communicative significance.

Effects of Various Antiepileptics Used to Alleviate Neuropathic Pain on Compound Action Potential in Frog Sciatic Nerves: Comparison with Those of Local Anesthetics

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Yuhei Uemura

2014-01-01

Full Text Available Antiepileptics used for treating neuropathic pain have various actions including voltage-gated Na+ and Ca2+ channels, glutamate-receptor inhibition, and GABAA-receptor activation, while local anesthetics are also used to alleviate the pain. It has not been fully examined yet how nerve conduction inhibitions by local anesthetics differ in extent from those by antiepileptics. Fast-conducting compound action potentials (CAPs were recorded from frog sciatic nerve fibers by using the air-gap method. Antiepileptics (lamotrigine and carbamazepine concentration dependently reduced the peak amplitude of the CAP (IC50=0.44 and 0.50 mM, resp.. Carbamazepine analog oxcarbazepine exhibited an inhibition smaller than that of carbamazepine. Antiepileptic phenytoin (0.1 mM reduced CAP amplitude by 15%. On the other hand, other antiepileptics (gabapentin, sodium valproate, and topiramate at 10 mM had no effect on CAPs. The CAPs were inhibited by local anesthetic levobupivacaine (IC50=0.23 mM. These results indicate that there is a difference in the extent of nerve conduction inhibition among antiepileptics and that some antiepileptics inhibit nerve conduction with an efficacy similar to that of levobupivacaine or to those of other local anesthetics (lidocaine, ropivacaine, and cocaine as reported previously. This may serve to know a contribution of nerve conduction inhibition in the antinociception by antiepileptics.

Fiber Optic Sensors For Detection of Toxic and Biological Threats

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Jianming Yuan

2007-12-01

Full Text Available Protection of public and military personnel from chemical and biological warfareagents is an urgent and growing national security need. Along with this idea, we havedeveloped a novel class of fiber optic chemical sensors, for detection of toxic and biologicalmaterials. The design of these fiber optic sensors is based on a cladding modificationapproach. The original passive cladding of the fiber, in a small section, was removed and thefiber core was coated with a chemical sensitive material. Any change in the opticalproperties of the modified cladding material, due to the presence of a specific chemicalvapor, changes the transmission properties of the fiber and result in modal powerredistribution in multimode fibers. Both total intensity and modal power distribution (MPDmeasurements were used to detect the output power change through the sensing fibers. TheMPD technique measures the power changes in the far field pattern, i.e. spatial intensitymodulation in two dimensions. Conducting polymers, such as polyaniline and polypyrrole,have been reported to undergo a reversible change in conductivity upon exposure tochemical vapors. It is found that the conductivity change is accompanied by optical propertychange in the material. Therefore, polyaniline and polypyrrole were selected as the modifiedcladding material for the detection of hydrochloride (HCl, ammonia (NH3, hydrazine(H4N2, and dimethyl-methl-phosphonate (DMMP {a nerve agent, sarin stimulant},respectively. Several sensors were prepared and successfully tested. The results showeddramatic improvement in the sensor sensitivity, when the MPD method was applied. In thispaper, an overview on the developed class of fiber optic sensors is presented and supportedwith successful achieved results.

The nervus terminalis in the chick: a FMRFamide-immunoreactive and AChE-positive nerve.

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Wirsig-Wiechmann, C R

1990-07-16

The chick terminal nerve (TN) was examined by immunocytochemical and histochemical methods. Molluscan cardioexcitatory peptide-immunoreactive (FMRFamide-ir) and acetylcholinesterase (AChE)-positive TN perikarya and fibers were distributed along olfactory and trigeminal nerves. FMRFamide-ir TN fibers terminated in the olfactory lamina propria and epithelium and in ganglia along the rostroventral nasal septum. This initial description of several populations of avian TN neurons should provide the foundation for future developmental studies of this system.

The Relationship between Peripheral Nerve Conduction Velocity and Ophthalmological Findings in Type 2 Diabetes Patients with Early Diabetic Retinopathy

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Azusa Ito

2018-01-01

Full Text Available Purpose. Nerve conduction velocity (NCV is an indicator of neuronal damage in the distal segment of the peripheral nerves. Here, we determined the association between NCV and other systemic and ocular clinical findings, in type 2 diabetes patients with early diabetic retinopathy (DR. Methods. This study included 42 eyes of 42 type 2 diabetes patients (median age: 54 years with no DR or with mild nonproliferative DR. Standard statistical techniques were used to determine associations between clinical findings. Results. Sural sensory conduction velocity (SCV and tibial motor conduction velocity (MCV were significantly lower in mild nonproliferative DR patients than patients with no DR (P=0.008 and P=0.01, resp.. Furthermore, logistic regression analyses revealed that sural SCV and tibial MCV were independent factors contributing to the presence of mild nonproliferative DR (OR 0.83, P=0.012 and OR 0.69 P=0.02, resp.. Tibial MCV was correlated with choroidal thickness (CT (P=0.01, and a multiple regression analysis revealed that age, tibial MCV, and carotid intima-media thickness were independent associating factors with CT (P=0.035, P=0.015, and P=0.008, resp.. Conclusions. Our findings suggest that reduced NCV may be closely associated with early DR in type 2 diabetes patients. Thus, reduced nerve conduction is a potential early biomarker of DR.

Enhancement of Median Nerve Regeneration by Mesenchymal Stem Cells Engraftment in an Absorbable Conduit: Improvement of Peripheral Nerve Morphology with Enlargement of Somatosensory Cortical Representation.

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Julia Teixeira Oliveira

2014-10-01

Full Text Available We studied the morphology and the cortical representation of the median nerve (MN, 10 weeks after a transection immediately followed by treatment with tubulization using a polycaprolactone (PCL conduit with or without bone marrow-derived mesenchymal stem cell (MSC transplant. In order to characterize the cutaneous representation of MN inputs in primary somatosensory cortex (S1, electrophysiological cortical mapping of the somatosensory representation of the forepaw and adjacent body parts was performed after acute lesion of all brachial plexus nerves, except for the MN. This was performed in ten adult male Wistar rats randomly assigned in 3 groups: MN Intact (n=4, PCL-Only (n=3 and PCL+MSC (n=3. Ten weeks before mapping procedures in animals from PCL-Only and PCL+MSC groups, animal were subjected to MN transection with removal of a 4-mm-long segment, immediately followed by suturing a PCL conduit to the nerve stumps with (PCL+MSC group or without (PCL-Only group injection of MSC into the conduit. After mapping the representation of the MN in S1, animals had a segment of the regenerated nerve processed for light and transmission electron microscopy. For histomorphometric analysis of the nerve segment, sample size was increased to 5 animals per experimental group. The PCL+MSC group presented a higher number of myelinated fibers and a larger cortical representation of MN inputs in S1 (3,383±390 fibers; 2.3 mm2, respectively than the PCL-Only group (2,226±575 fibers; 1.6 mm2. In conclusion, MSC-based therapy associated with PCL conduits can improve MN regeneration. This treatment seems to rescue the nerve representation in S1, thus minimizing the stabilization of new representations of adjacent body parts in regions previously responsive to the MN.

Morphology of nerve endings in vocal fold of human newborn.

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Gonçalves da Silva Leite, Janaina; Costa Cavalcante, Maria Luzete; Fechine-Jamacaru, Francisco Vagnaldo; de Lima Pompeu, Margarida Maria; Leite, José Alberto Dias; Nascimento Coelho, Dulce Maria; Rabelo de Freitas, Marcos

2016-10-01

Sensory receptors are distributed throughout the oral cavity, pharynx, and larynx. Laryngeal sensitivity is crucial for maintaining safe swallowing, thus avoiding silent aspiration. Morphologic description of different receptor types present in larynx vary because of the study of many different species, from mouse to humans. The most commonly sensory structures described in laryngeal mucosa are free nerve endings, taste buds, muscle spindles, glomerular and corpuscular receptors. This study aimed at describing the morphology and the distribution of nerve endings in premature newborn glottic region. Transversal serial frozen sections of the whole vocal folds of three newborns were analyzed using an immuno-histochemical process with a pan-neuronal marker anti-protein gene product 9.5 (PGP 9.5). Imaging was done using a confocal laser microscope. Nerve fiber density in vocal cord was calculated using panoramic images in software Morphometric Analysis System v1.0. Some sensory structures, i.e. glomerular endings and intraepithelial free nerve endings were found in the vocal cord mucosa. Muscle spindles, complex nerve endings (Meissner-like, spherical, rectangular and growing) spiral-wharves nerve structures were identified in larynx intrinsic muscles. Nervous total mean density in vocal cord was similar in the three newborns, although they had different gestational age. The mean nerve fiber density was higher in the posterior region than anterior region of vocal cord. The present results demonstrate the occurrence of different morphotypes of sensory corpuscles and nerve endings premature newborn glottic region and provide information on their sensory systems. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Preparation of conductive paper composites based on natural cellulosic fibers for packaging applications.

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Youssef, Ahmed M; El-Samahy, Magda Ali; Abdel Rehim, Mona H

2012-08-01

Conducting paper based on natural cellulosic fibers and conductive polymers was prepared using unbleached bagasse and/or rice straw fibers (as cellulosic raw materials) and polyaniline (PANi) as conducting polymer. These composites were synthesized by in situ emulsion polymerization using ammonium persulfate (APS) as oxidant in the presence of dodecylbenzene sulfonic acid (DBSA) as emulsifier. The prepared composites were characterized using Fourier transform infrared (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimeter (DSC), and their morphology was investigated using scanning electron microscope (SEM). Electrical conductivity measurements showed that the conductivity of the paper sheets increases by increasing the ratio of PANi in the composite. Mechanical properties of the paper sheets were also investigated, the results revealed that the values of breaking length, burst factor, and tear factor are decreased with increasing ratio of added PANi, and this effect is more pronounced in bagasse-based composites. The new conductive composites can have potential use as anti-static packaging material or anti-bacterial paper for packaging applications. Copyright © 2012 Elsevier Ltd. All rights reserved.

Complementary effects of two growth factors in multifunctionalized silk nanofibers for nerve reconstruction.

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Tony M Dinis

Full Text Available With the aim of forming bioactive guides for peripheral nerve regeneration, silk fibroin was electrospun to obtain aligned nanofibers. These fibers were functionalized by incorporating Nerve Growth Factor (NGF and Ciliary NeuroTrophic Factor (CNTF during electrospinning. PC12 cells grown on the fibers confirmed the bioavailability and bioactivity of the NGF, which was not significantly released from the fibers. Primary neurons from rat dorsal root ganglia (DRGs were grown on the nanofibers and anchored to the fibers and grew in a directional fashion based on the fiber orientation, and as confirmed by growth cone morphology. These biofunctionalized nanofibers led to a 3-fold increase in neurite length at their contact, which was likely due to the NGF. Glial cell growth, alignment and migration were stimulated by the CNTF in the functionalized nanofibers. Organotypic culture of rat fetal DRGs confirmed the complementary effect of both growth factors in multifunctionalized nanofibers, which allowed glial cell migration, alignment and parallel axonal growth in structures resembling the 'bands of Bungner' found in situ. Graftable multi-channel conduits based on biofunctionalized aligned silk nanofibers were developed as an organized 3D scaffold. Our bioactive silk tubes thus represent new options for a biological and biocompatible nerve guidance conduit.

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.

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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.

Ni Nanobuffer Layer Provides Light-Weight CNT/Cu Fibers with Superior Robustness, Conductivity, and Ampacity.

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Zou, Jingyun; Liu, Dandan; Zhao, Jingna; Hou, Ligan; Liu, Tong; Zhang, Xiaohua; Zhao, Yonghao; Zhu, Yuntian T; Li, Qingwen

2018-03-07

Carbon nanotube (CNT) fiber has not shown its advantage as next-generation light-weight conductor due to the large contact resistance between CNTs, as reflected by its low conductivity and ampacity. Coating CNT fiber with a metal layer like Cu has become an effective solution to this problem. However, the weak CNT-Cu interfacial bonding significantly limits the mechanical and electrical performances. Here, we report that a strong CNT-Cu interface can be formed by introducing a Ni nanobuffer layer before depositing the Cu layer. The Ni nanobuffer layer remarkably promotes the load and heat transfer efficiencies between the CNT fiber and Cu layer and improves the quality of the deposited Cu layer. As a result, the new composite fiber with a 2 μm thick Cu layer can exhibit a superhigh effective strength >800 MPa, electrical conductivity >2 × 10 7 S/m, and ampacity >1 × 10 5 A/cm 2 . The composite fiber can also sustain 10 000 times of bending and continuously work for 100 h at 90% ampacity.

Streptozocin-induced type-1 diabetes mellitus results in decreased density of CGRP sensory and TH sympathetic nerve fibers that are positively correlated with bone loss at the mouse femoral neck.

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Enríquez-Pérez, Iris A; Galindo-Ordoñez, Karla E; Pantoja-Ortíz, Christian E; Martínez-Martínez, Arisaí; Acosta-González, Rosa I; Muñoz-Islas, Enriqueta; Jiménez-Andrade, Juan M

2017-08-10

Type-1 diabetes mellitus (T1DM) results in loss of innervation in some tissues including epidermis and retina; however, the effect on bone innervation is unknown. Likewise, T1DM results in pathological bone loss and increased risk of fracture. Thus, we quantified the density of calcitonin gene-related peptide (CGRP + ) sensory and tyrosine hydroxylase (TH + ) sympathetic nerve fibers and determined the association between the innervation density and microarchitecture of trabecular bone at the mouse femoral neck. Ten weeks-old female mice received 5 daily administrations of streptozocin (i.p. 50mg/kg) or citrate (control group). Twenty weeks later, femurs were analyzed by microCT and processed for immunohistochemistry. Confocal microscopy analysis revealed that mice with T1DM had a significant loss of both CGRP + and TH + nerve fibers in the bone marrow at the femoral neck. Likewise, microCT analysis revealed a significant decrease in the trabecular bone mineral density (tBMD), bone volume/total volume ratio (BV/TB), trabecular thickness (Tb.Th), trabecular number (Tb.N) and trabecular separation (Tb.Sp) in mice with T1DM as compared to control mice. Analysis of correlation revealed a positive and significant association between density of CGRP + or TH + nerve fibers with tBMD, BV/TV, Tb.Th and Tb.Sp, but not with trabecular number (there was a positive association only for CGRP + ) and degree of anisotropy (DA). This study suggests an interaction between sensory and sympathetic nervous system and T1DM-induced bone loss. Identification of the factors involved in the loss of CGRP + sensory and TH + sympathetic fibers and how they regulate bone loss may result in new avenues to treat T1DM-related osteoporosis. Copyright © 2017 Elsevier B.V. All rights reserved.

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

Nervus terminalis, olfactory nerve, and optic nerve representation of luteinizing hormone-releasing hormone in primates.

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Witkin, J W

1987-01-01

The luteinizing hormone-releasing hormone (LHRH) system was examined immunocytochemically in olfactory bulbs of adult monkeys, including two New World species (squirrel monkey, Saimiri sciureus and owl monkey, Aotus trivirgatus) and one Old World species (cynomolgus macaque, Macaca fasciculata), and in the brain and nasal region of a fetal rhesus macaque Macaca mulatta. LHRH neurons and fibers were found sparsely distributed in the olfactory bulbs in all adult monkeys. There was more LHRH in the accessory olfactory bulb (which is absent in Old World monkeys). In the fetal macaque there was a rich distribution of LHRH neurons and fibers along the pathway of the nervus terminalis, anterior and ventral to the olfactory bulb, and in the nasal septum, with fibers branching into the olfactory epithelium. In addition, there were LHRH neurons and fibers in the optic nerve.

Benefits of Ilizarov automated bone distraction for nerves and articular cartilage in experimental leg lengthening.

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Shchudlo, Nathalia; Varsegova, Tatyana; Stupina, Tatyana; Shchudlo, Michael; Saifutdinov, Marat; Yemanov, Andrey

2017-09-18

To determine peculiarities of tissue responses to manual and automated Ilizarov bone distraction in nerves and articular cartilage. Twenty-nine dogs were divided in two experimental groups: Group M - leg lengthening with manual distraction (1 mm/d in 4 steps), Group A - automated distraction (1 mm/d in 60 steps) and intact group. Animals were euthanized at the end of distraction, at 30 th day of fixation in apparatus and 30 d after the fixator removal. M-responses in gastrocnemius and tibialis anterior muscles were recorded, numerical histology of peroneal and tibialis nerves and knee cartilage semi-thin sections, scanning electron microscopy and X-ray electron probe microanalysis were performed. Better restoration of M-response amplitudes in leg muscles was noted in A-group. Fibrosis of epineurium with adipocytes loss in peroneal nerve, subperineurial edema and fibrosis of endoneurium in some fascicles of both nerves were noted only in M-group, shares of nerve fibers with atrophic and degenerative changes were bigger in M-group than in A-group. At the end of experiment morphometric parameters of nerve fibers in peroneal nerve were comparable with intact nerve only in A-group. Quantitative parameters of articular cartilage (thickness, volumetric densities of chondrocytes, percentages of isogenic clusters and empty cellular lacunas, contents of sulfur and calcium) were badly changed in M-group and less changed in A-group. Automated Ilizarov distraction is more safe method of orthopedic leg lengthening than manual distraction in points of nervous fibers survival and articular cartilage arthrotic changes.

Exercise training improves functional recovery and motor nerve conduction velocity after sciatic nerve crush lesion in the rat

NARCIS (Netherlands)

Gispen, W.H.; Meeteren, N.L.U.; Brakkee, J.H.; Hamers, F.P.T.; Helders, P.J.M.

1997-01-01

Objective: To observe the effects of exercise training on recuperation of sensorimotor function in the early phase of regeneration, and to monitor the long-term effects of exercise on electrophysiological aspects of the regenerating nerve. Design: After sciatic nerve crush in 20 male Wistar rats,

Using in-situ polymerization of conductive polymers to enhance the electrical properties of solution-processed carbon nanotube films and fibers.

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Allen, Ranulfo; Pan, Lijia; Fuller, Gerald G; Bao, Zhenan

2014-07-09

Single-walled carbon nanotubes/polymer composites typically have limited conductivity due to a low concentration of nanotubes and the insulating nature of the polymers used. Here we combined a method to align carbon nanotubes with in-situ polymerization of conductive polymer to form composite films and fibers. Use of the conducting polymer raised the conductivity of the films by 2 orders of magnitude. On the other hand, CNT fiber formation was made possible with in-situ polymerization to provide more mechanical support to the CNTs from the formed conducting polymer. The carbon nanotube/conductive polymer composite films and fibers had conductivities of 3300 and 170 S/cm, respectively. The relatively high conductivities were attributed to the polymerization process, which doped both the SWNTs and the polymer. In-situ polymerization can be a promising solution-processable method to enhance the conductivity of carbon nanotube films and fibers.