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Sample records for polarization-sensitive descending neurons

  1. Identifying local and descending inputs for primary sensory neurons.

    Science.gov (United States)

    Zhang, Yi; Zhao, Shengli; Rodriguez, Erica; Takatoh, Jun; Han, Bao-Xia; Zhou, Xiang; Wang, Fan

    2015-10-01

    Primary pain and touch sensory neurons not only detect internal and external sensory stimuli, but also receive inputs from other neurons. However, the neuronal derived inputs for primary neurons have not been systematically identified. Using a monosynaptic rabies viruses-based transneuronal tracing method combined with sensory-specific Cre-drivers, we found that sensory neurons receive intraganglion, intraspinal, and supraspinal inputs, the latter of which are mainly derived from the rostroventral medulla (RVM). The viral-traced central neurons were largely inhibitory but also consisted of some glutamatergic neurons in the spinal cord and serotonergic neurons in the RVM. The majority of RVM-derived descending inputs were dual GABAergic and enkephalinergic (opioidergic). These inputs projected through the dorsolateral funiculus and primarily innervated layers I, II, and V of the dorsal horn, where pain-sensory afferents terminate. Silencing or activation of the dual GABA/enkephalinergic RVM neurons in adult animals substantially increased or decreased behavioral sensitivity, respectively, to heat and mechanical stimuli. These results are consistent with the fact that both GABA and enkephalin can exert presynaptic inhibition of the sensory afferents. Taken together, this work provides a systematic view of and a set of tools for examining peri- and extrasynaptic regulations of pain-afferent transmission.

  2. Descending Command Neurons in the Brainstem that Halt Locomotion

    DEFF Research Database (Denmark)

    Bouvier, Julien; Caggiano, Vittorio; Leiras, Roberto

    2015-01-01

    identifiable brainstem populations to a potential locomotor stop signal, we used developmental genetics and considered a discrete neuronal population in the reticular formation: the V2a neurons. We find that those neurons constitute a major excitatory pathway to locomotor areas of the ventral spinal cord....... Selective activation of V2a neurons of the rostral medulla stops ongoing locomotor activity, owing to an inhibition of premotor locomotor networks in the spinal cord. Moreover, inactivation of such neurons decreases spontaneous stopping in vivo. Therefore, the V2a "stop neurons" represent a glutamatergic...

  3. Long descending cervical propriospinal neurons differ from thoracic propriospinal neurons in response to low thoracic spinal injury

    Directory of Open Access Journals (Sweden)

    Stelzner Dennis J

    2010-11-01

    Full Text Available Abstract Background Propriospinal neurons, with axonal projections intrinsic to the spinal cord, have shown a greater regenerative response than supraspinal neurons after axotomy due to spinal cord injury (SCI. Our previous work focused on the response of axotomized short thoracic propriospinal (TPS neurons following a low thoracic SCI (T9 spinal transection or moderate spinal contusion injury in the rat. The present investigation analyzes the intrinsic response of cervical propriospinal neurons having long descending axons which project into the lumbosacral enlargement, long descending propriospinal tract (LDPT axons. These neurons also were axotomized by T9 spinal injury in the same animals used in our previous study. Results Utilizing laser microdissection (LMD, qRT-PCR, and immunohistochemistry, we studied LDPT neurons (located in the C5-C6 spinal segments between 3-days, and 1-month following a low thoracic (T9 spinal cord injury. We examined the response of 89 genes related to growth factors, cell surface receptors, apoptosis, axonal regeneration, and neuroprotection/cell survival. We found a strong and significant down-regulation of ~25% of the genes analyzed early after injury (3-days post-injury with a sustained down-regulation in most instances. In the few genes that were up-regulated (Actb, Atf3, Frs2, Hspb1, Nrap, Stat1 post-axotomy, the expression for all but one was down-regulated by 2-weeks post-injury. We also compared the uninjured TPS control neurons to the uninjured LDPT neurons used in this experiment for phenotypic differences between these two subpopulations of propriospinal neurons. We found significant differences in expression in 37 of the 84 genes examined between these two subpopulations of propriospinal neurons with LDPT neurons exhibiting a significantly higher base line expression for all but 3 of these genes compared to TPS neurons. Conclusions Taken collectively these data indicate a broad overall down

  4. Activity in descending dopaminergic neurons represents but is not required for leg movements in the fruit fly Drosophila

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    Tschida, Katherine; Bhandawat, Vikas

    2015-01-01

    Modulatory descending neurons (DNs) that link the brain to body motor circuits, including dopaminergic DNs (DA-DNs), are thought to contribute to the flexible control of behavior. Dopamine elicits locomotor-like outputs and influences neuronal excitability in isolated body motor circuits over tens of seconds to minutes, but it remains unknown how and over what time scale DA-DN activity relates to movement in behaving animals. To address this question, we identified DA-DNs in the Drosophila brain and developed an electrophysiological preparation to record and manipulate the activity of these cells during behavior. We find that DA-DN spike rates are rapidly modulated during a subset of leg movements and scale with the total speed of ongoing leg movements, whether occurring spontaneously or in response to stimuli. However, activating DA-DNs does not elicit leg movements in intact flies, nor do acute bidirectional manipulations of DA-DN activity affect the probability or speed of leg movements over a time scale of seconds to minutes. Our findings indicate that in the context of intact descending control, changes in DA-DN activity are not sufficient to influence ongoing leg movements and open the door to studies investigating how these cells interact with other descending and local neuromodulatory inputs to influence body motor output. PMID:25742959

  5. Mirror movement-like defects in startle behavior of zebrafish dcc mutants are caused by aberrant midline guidance of identified descending hindbrain neurons.

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    Jain, Roshan A; Bell, Hannah; Lim, Amy; Chien, Chi-Bin; Granato, Michael

    2014-02-19

    Mirror movements are involuntary movements on one side of the body that occur simultaneously with intentional movements on the contralateral side. Humans with heterozygous mutations in the axon guidance receptor DCC display such mirror movements, where unilateral stimulation results in inappropriate bilateral motor output. Currently, it is unclear whether mirror movements are caused by incomplete midline crossing and reduced commissural connectivity of DCC-dependent descending pathways or by aberrant ectopic ipsilateral axonal projections of normally commissural neurons. Here, we show that in response to unilateral tactile stimuli, zebrafish dcc mutant larvae perform involuntary turns on the inappropriate body side. We show that these mirror movement-like deficits are associated with axonal guidance defects of two identified groups of commissural reticulospinal hindbrain neurons. Moreover, we demonstrate that in dcc mutants, axons of these identified neurons frequently fail to cross the midline and instead project ipsilaterally. Whereas laser ablation of these neurons in wild-type animals does not affect turning movements, their ablation in dcc mutants restores turning movements. Thus, our results demonstrate that in dcc mutants, turns on the inappropriate side of the body are caused by aberrant ipsilateral axonal projections, and suggest that aberrant ipsilateral connectivity of a very small number of descending axons is sufficient to induce incorrect movement patterns.

  6. Polarization sensitive optical coherence tomography detection method

    International Nuclear Information System (INIS)

    Colston, B W; DaSilva, L B; Everett, M J; Featherstone, J D B; Fried, D; Ragadio, J N; Sathyam, U S.

    1999-01-01

    This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattering coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions

  7. Polarization sensitive optical frequency domain imaging system for endobronchial imaging

    NARCIS (Netherlands)

    Li, J.; Feroldi, Fabio; de Lange, J.; Daniels, J.M.A.; Grünberg, K.; de Boer, J.F.

    2015-01-01

    A polarization sensitive endoscopic optical frequency domain imaging (PS-OFDI) system with a motorized distal scanning catheter is demonstrated. It employs a passive polarization delay unit to multiplex two orthogonal probing polarization states in depth, and a polarization diverse detection unit to

  8. The Influence of Inflammation and Nerve Damage on the Neurochemical Characterization of Calcitonin Gene-Related Peptide—Like Immunoreactive (CGRP-LI Neurons in the Enteric Nervous System of the Porcine Descending Colon

    Directory of Open Access Journals (Sweden)

    Krystyna Makowska

    2018-02-01

    Full Text Available The enteric nervous system (ENS, localized in the wall of the gastrointestinal tract, regulates the functions of the intestine using a wide range of neuronally-active substances. One of them is the calcitonin gene-related peptide (CGRP, whose participation in pathological states in the large intestine remains unclear. Therefore, the aim of this study was to investigate the influence of inflammation and nerve damage using a double immunofluorescence technique to neurochemically characterize CGRP-positive enteric nervous structures in the porcine descending colon. Both pathological factors caused an increase in the percentage of CGRP-positive enteric neurons, and these changes were the most visible in the myenteric plexus after nerve damage. Moreover, both pathological states change the degree of co-localization of CGRP with other neurochemical factors, including substance P, the neuronal isoform of nitric oxide synthase, galanin, cocaine- and amphetamine-regulated transcript peptide and vesicular acetylcholine transporter. The character and severity of these changes depended on the pathological factor and the type of enteric plexus. The obtained results show that CGRP-positive enteric neurons are varied in terms of neurochemical characterization and take part in adaptive processes in the descending colon during inflammation and after nerve damage.

  9. The Influence of Low Doses of Zearalenone and T-2 Toxin on Calcitonin Gene Related Peptide-Like Immunoreactive (CGRP-LI Neurons in the ENS of the Porcine Descending Colon

    Directory of Open Access Journals (Sweden)

    Krystyna Makowska

    2017-03-01

    Full Text Available The enteric nervous system (ENS can undergo adaptive and reparative changes in response to physiological and pathological stimuli. These manifest primarily as alterations in the levels of active substances expressed by the enteric neuron. While it is known that mycotoxins can affect the function of the central and peripheral nervous systems, knowledge about their influence on the ENS is limited. Therefore, the aim of the present study was to investigate the influence of low doses of zearalenone (ZEN and T-2 toxin on calcitonin gene related peptide-like immunoreactive (CGRP-LI neurons in the ENS of the porcine descending colon using a double immunofluorescence technique. Both mycotoxins led to an increase in the percentage of CGRP-LI neurons in all types of enteric plexuses and changed the degree of co-localization of CGRP with other neuronal active substances, such as substance P, galanin, nitric oxide synthase, and cocaine- and amphetamine-regulated transcript peptide. The obtained results demonstrate that even low doses of ZEN and T-2 can affect living organisms and cause changes in the neurochemical profile of enteric neurons.

  10. Topological insulator infrared pseudo-bolometer with polarization sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Peter Anand

    2017-10-25

    Topological insulators can be utilized in a new type of infrared photodetector that is intrinsically sensitive to the polarization of incident light and static magnetic fields. The detector isolates single topological insulator surfaces and allows light collection and exposure to static magnetic fields. The wavelength range of interest is between 750 nm and about 100 microns. This detector eliminates the need for external polarization selective optics. Polarization sensitive infrared photodetectors are useful for optoelectronics applications, such as light detection in environments with low visibility in the visible wavelength regime.

  11. A vertebrate retina with segregated colour and polarization sensitivity.

    Science.gov (United States)

    Novales Flamarique, Iñigo

    2017-09-13

    Besides colour and intensity, some invertebrates are able to independently detect the polarization of light. Among vertebrates, such separation of visual modalities has only been hypothesized for some species of anchovies whose cone photoreceptors have unusual ultrastructure that varies with retinal location. Here, I tested this hypothesis by performing physiological experiments of colour and polarization discrimination using the northern anchovy, Engraulis mordax Optic nerve recordings showed that the ventro-temporal (VT), but not the ventro-nasal (VN), retina was polarization sensitive, and this coincided with the exclusive presence of polarization-sensitive photoreceptors in the VT retina. Spectral (colour) sensitivity recordings from the VN retina indicated the contribution of two spectral cone mechanisms to the optic nerve response, whereas only one contributed to the VT retina. This was supported by the presence of only one visual pigment in the VT retina and two in the VN retina, suggesting that only the VN retina was associated with colour sensitivity. Behavioural tests further demonstrated that anchovies could discriminate colour and the polarization of light using the ventral retina. Thus, in analogy with the visual system of some invertebrates, the northern anchovy has a retina with segregated retinal pathways for colour and polarization vision. © 2017 The Author(s).

  12. Inter-individual variation in reciprocal Ia inhibition is dependent on the descending volleys delivered from corticospinal neurons to Ia interneurons.

    Science.gov (United States)

    Kubota, Shinji; Uehara, Kazumasa; Morishita, Takuya; Hirano, Masato; Funase, Kozo

    2014-02-01

    We investigated the extent to which the corticospinal inputs delivered to Ia inhibitory interneurons influence the strength of disynaptic reciprocal Ia inhibition. Seventeen healthy subjects participated in this study. The degree of reciprocal Ia inhibition was determined via short-latency (condition-test interval: 1-3ms) suppression of Sol H-reflex by conditioning stimulation of common peroneal nerve. The effect of corticospinal descending inputs on Ia inhibitory interneurons was assessed by evaluating the conditioning effect of transcranial magnetic stimulation (TMS) on the Sol H-reflex. Then, we determined the relationship between the degree of reciprocal Ia inhibition and the conditioning effect of TMS on the Sol H-reflex. We found that the degree of reciprocal Ia inhibition and the extent of change in the amplitude of the TMS-conditioned H-reflex, which was measured from short latency facilitation to inhibition, displayed a strong correlation (r=0.76, pIa inhibition is affected by the corticospinal descending inputs delivered to Ia inhibitory interneurons, which might explain the inter-individual variations in reciprocal Ia inhibition. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Advanced polarization sensitive analysis in optical coherence tomography

    Science.gov (United States)

    Wieloszyńska, Aleksandra; StrÄ kowski, Marcin R.

    2017-08-01

    The optical coherence tomography (OCT) is an optical imaging method, which is widely applied in variety applications. This technology is used to cross-sectional or surface imaging with high resolution in non-contact and non-destructive way. OCT is very useful in medical applications like ophthalmology, dermatology or dentistry, as well as beyond biomedical fields like stress mapping in polymers or protective coatings defects detection. Standard OCT imaging is based on intensity images which can visualize the inner structure of scattering devices. However, there is a number of extensions improving the OCT measurement abilities. The main of them are the polarization sensitive OCT (PS-OCT), Doppler enable OCT (D-OCT) or spectroscopic OCT (S-OCT). Our research activities have been focused on PS-OCT systems. The polarization sensitive analysis delivers an useful information about optical anisotropic properties of the evaluated sample. This kind of measurements is very important for inner stress monitoring or e.g. tissue recognition. Based on our research results and knowledge the standard PS-OCT provide only data about birefringence of the measured sample. However, based on the OCT measurements more information including depolarization and diattenuation might be obtained. In our work, the method based on Jones formalism are going to be presented. It is used to determine birefringence, dichroism and optic axis orientation of the tested sample. In this contribution the setup of the optical system, as well as tests results verifying the measurements abilities of the system are going to be presented. The brief discussion about the effectiveness and usefulness of this approach will be carried out.

  14. Polarization sensitive optical frequency domain imaging system for endobronchial imaging.

    Science.gov (United States)

    Li, Jianan; Feroldi, Fabio; de Lange, Joop; Daniels, Johannes M A; Grünberg, Katrien; de Boer, Johannes F

    2015-02-09

    A polarization sensitive endoscopic optical frequency domain imaging (PS-OFDI) system with a motorized distal scanning catheter is demonstrated. It employs a passive polarization delay unit to multiplex two orthogonal probing polarization states in depth, and a polarization diverse detection unit to detect interference signal in two orthogonal polarization channels. Per depth location four electro-magnetic field components are measured that can be represented in a complex 2x2 field matrix. A Jones matrix of the sample is derived and the sample birefringence is extracted by eigenvalue decomposition. The condition of balanced detection and the polarization mode dispersion are quantified. A complex field averaging method based on the alignment of randomly pointing field phasors is developed to reduce speckle noise. The variation of the polarization states incident on the tissue due to the circular scanning and catheter sheath birefringence is investigated. With this system we demonstrated imaging of ex vivo chicken muscle, in vivo pig lung and ex vivo human lung specimens.

  15. THE ATACAMA COSMOLOGY TELESCOPE: THE POLARIZATION-SENSITIVE ACTPol INSTRUMENT

    Energy Technology Data Exchange (ETDEWEB)

    Thornton, R. J. [Department of Physics, West Chester University of Pennsylvania, West Chester, PA 19383 (United States); Ade, P. A. R. [School of Physics and Astronomy, Cardiff University, The Parade, Cardiff, Wales, CF24 3AA (United Kingdom); Aiola, S. [Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA 15260 (United States); Angilè, F. E.; Devlin, M. J.; Dicker, S. R. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Amiri, M. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z4 (Canada); Beall, J. A.; Becker, D. T.; Fowler, J. W.; Fox, A. E.; Gao, J. [NIST Quantum Sensors Group, 325 Broadway Mailcode 817.03, Boulder, CO 80305 (United States); Cho, H-M. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Choi, S. K.; Grace, E. [Joseph Henry Laboratories of Physics, Jadwin Hall, Princeton University, Princeton, NJ 08544 (United States); Corlies, P.; Gallardo, P. A. [Department of Physics, Cornell University, Ithaca, NY 14853 (United States); Coughlin, K. P.; Datta, R. [Department of Physics, University of Michigan Ann Arbor, MI 48109 (United States); Dünner, R. [Instituto de Astrofísica and Centro de Astro-Ingeniería, Facultad de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4860, 7820436 Macul, Santiago (Chile); and others

    2016-12-01

    The Atacama Cosmology Telescope (ACT) makes high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3° field of view, 100 mK cryogenics with continuous cooling, and meta material antireflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev–Zel’dovich (SZ) and kinetic SZ signals, and CMB lensing due to large-scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the full suite of three arrays. This paper provides an overview of the design and initial performance of the receiver and related systems.

  16. The Atacama Cosmology Telescope: The Polarization-Sensitive ACTPol Instrument

    Science.gov (United States)

    Thornton, R. J.; Ade, P. A. R.; Aiola, S.; Angile, F. E.; Amiri, M.; Beall, J. A.; Becker, D. T.; Cho, H.-M.; Choi, S. K.; Corlies, P.; hide

    2016-01-01

    The Atacama Cosmology Telescope (ACT) makes high angular resolution measurements of anisotropies in the Cosmic Microwave Background (CMB) at millimeter wavelengths. We describe ACTPol, an upgraded receiver for ACT, which uses feedhorn-coupled, polarization-sensitive detector arrays, a 3deg field of view, 100 mK cryogenics with continuous cooling, and meta material antireflection coatings. ACTPol comprises three arrays with separate cryogenic optics: two arrays at a central frequency of 148 GHz and one array operating simultaneously at both 97 GHz and 148 GHz. The combined instrument sensitivity, angular resolution, and sky coverage are optimized for measuring angular power spectra, clusters via the thermal Sunyaev-Zel'dovich (SZ) and kinetic SZ signals, and CMB lensing due to large-scale structure. The receiver was commissioned with its first 148 GHz array in 2013, observed with both 148 GHz arrays in 2014, and has recently completed its first full season of operations with the full suite of three arrays. This paper provides an overview of the design and initial performance of the receiver and related systems.

  17. Polarization sensitive beam bending using a spatially variant photonic crystal

    Science.gov (United States)

    Digaum, Jennefir L.; Pazos, Javier; Rumpf, Raymond; Chiles, Jeff; Fathpour, Sasan; Thomas, Jeremy N.; Kuebler, Stephen M.

    2015-02-01

    A spatially-variant photonic crystal (SVPC) that can control the spatial propagation of electromagnetic waves in three dimensions with high polarization sensitivity was fabricated and characterized. The geometric attributes of the SVPC lattice were spatially varied to make use of the directional phenomena of self-collimation to tightly bend an unguided beam coherently through a 90 degree angle. Both the lattice spacing and the fill factor of the SVPC were maintained to be nearly constant throughout the structure. A finite-difference frequency-domain computational method confirms that the SVPC can self-collimate and bend light without significant diffuse scatter caused by the bend. The SVPC was fabricated using multi-photon direct laser writing in the photo-polymer SU-8. Mid-infrared light having a vacuum wavelength of λ0 = 2.94 μm was used to experimentally characterize the SVPCs by scanning the sides of the structure with optical fibers and measuring the intensity of light emanating from each face. Results show that the SVPC is capable of directing power flow of one polarization through a 90-degree turn, confirming the self-collimating and polarization selective light-guiding properties of the structures.

  18. Polarization sensitive optical coherence tomography in equine bone

    Science.gov (United States)

    Jacobs, J. W.; Matcher, S. J.

    2009-02-01

    Optical coherence tomography (OCT) has been used to image equine bone samples. OCT and polarization sensitive OCT (PS-OCT) images of equine bone samples, before and after demineralization, are presented. Using a novel approach, taking a series of images at different angles of illumination, the polar angle and true birefringence of collagen within the tissue is determined, at one site in the sample. The images were taken before and after the bones were passed through a demineralization process. The images show an improvement in depth penetration after demineralization allowing better visualization of the internal structure of the bone and the optical orientation of the collagen. A quantitative measurement of true birefringence has been made of the bone; true birefringence was shown to be 1.9x10-3 before demineralization increasing to 2.7x10-3 after demineralization. However, determined collagen fiber orientation remains the same before and after demineralization. The study of bone is extensive within the field of tissue engineering where an understanding of the internal structures is essential. OCT in bone, and improved depth penetration through demineralization, offers a useful approach to bone analysis.

  19. Polarization-sensitive optical frequency domain imaging based on unpolarized light

    NARCIS (Netherlands)

    Kim, K.H.; Park, B. H.; Tu, Y.P.; Hasan, T.; Lee, B.; Li, J.; de Boer, J.F.

    2011-01-01

    Polarization-sensitive optical coherence tomography (PS-OCT) is an augmented form of OCT, providing 3D images of both tissue structure and polarization properties. We developed a new method of polarization-sensitive optical frequency domain imaging (PS-OFDI), which is based on a wavelength-swept

  20. Descendent necrotizing mediastinitis

    International Nuclear Information System (INIS)

    Sanchez, Rodrigo Armando; Rueda, Luis Fernando

    2004-01-01

    Descendent necrotizing mediastinitis (DNM) is a rare and serious disease with a high mortality. A deep infection in the neck appears generally as the primary focus, as a odontogenic abscess, tonsil infection, pharyngeal or epiglottitis among others. Six cases of descendent necrotizing mediastinitis occurs between January of 1999 to June of 2004 in the hospital santa clara of bogota, colombia, are discussed. Different etiologies were present like odontogenic abscess, submaxillar abscess, retropharyngeal abscess, a cervical esophageal perforation secondary to treatment of a stenosis in the anastomosis between the cenical esophagus and the colon. All of the patients required surgical handling by means of drainage and debridement by cerevicotomy and thoracotomy, and in one case by means of sternotomy, added to antibiotic and intensive care support. Mortality was of 67%, with an average of hospital stay of 17 days

  1. Descendants of Slaves

    DEFF Research Database (Denmark)

    Marselis, Randi

    2008-01-01

    The aim of the Danish television documentary series Slavernes Slægt (Descendants of Slaves, 2005) has been to enhance public awareness of Danish colonial history. As is typical of contemporary mediated memories, the account of national history is combined with 'small histories' that focus on live...... stories of individuals and their families. Participating in the series are present-day descendants of enslaved Africans who, as a result of an interest in family historical research, have found information about their black ancestry. The series challenges the supposed historical homogeneity of Nordic...... nation-states by pointing out the historical presence of black individuals. However, this article will show how discourses of family history (e.g. the focus on bloodlines) converge with old 'race' theory; the result of which is that the series inadvertently reproduces processes of visual Othering....

  2. In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

    NARCIS (Netherlands)

    Kim, K.H.; Pierce, M. C.; Maguluri, G. N.; Park, B. H.; Yoon, S.J.; Lydan, M.; Sheridan, R.; de Boer, J.F.

    2012-01-01

    The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization- sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and

  3. Contribution of afferent feedback and descending drive to human hopping

    DEFF Research Database (Denmark)

    Zuur, Abraham T.; Lundbye-Jensen, Jesper; Leukel, Christian

    2010-01-01

    to inhibit the motor cortex and this resulted in a suppression of the early EMG burst. These results suggest that sensory feedback and descending drive from the motor cortex are integrated to drive the motor neuron pool during the early EMG burst in hopping. Thus, simple reflexes work in concert with higher...

  4. Insect remote sensing using a polarization sensitive cw lidar system in chinese rice fields

    Directory of Open Access Journals (Sweden)

    Zhu Shiming

    2018-01-01

    Full Text Available A joint Chinese-Swedish field campaign of Scheimpflug continuous-wave lidar monitoring of rice-field flying pest insects was pursued in very hot July weather conditions close to Guangzhou, China. The occurrence of insects, birds and bats with almost 200 hours of round-the-clock polarization-sensitive recordings was studied. Wing-beat frequency recordings and depolarization properties were used for target classification. Influence of weather conditions on the flying fauna was also investigated.

  5. Imaging of human breast tissue using polarization sensitive optical coherence tomography

    Science.gov (United States)

    Verma, Y.; Gautam, M.; Divakar Rao, K.; Swami, M. K.; Gupta, P. K.

    2011-12-01

    We report a study on the use of polarization sensitive optical coherence tomography (PSOCT) for discriminating malignant (invasive ductal carcinoma), benign (fibroadenoma) and normal (adipocytes) breast tissue sites. The results show that while conventional OCT, that utilizes only the intensity of light back-scattered from tissue microstructures, is able to discriminate breast tissues as normal (adipocytes) and abnormal (malignant and benign) tissues, PS-OCT helps in discriminating between malignant and benign tissue sites also. The estimated values of birefringence obtained from the PSOCT imaging show that benign breast tissue samples have significantly higher birefringence as compared to the malignant tissue samples.

  6. Non-invasive assessment of corneal crosslinking changes using polarization sensitive optical coherence tomography

    Science.gov (United States)

    Alonso-Caneiro, D.; Yamanari, M.; Fukuda, S.; Hoshi, S.; Nagase, S.; Oshika, T.; Yasuno, Y.; Collins, M.

    2013-03-01

    Collagen crosslinking (CXL) has shown promising results in the prevention of the progression of keratoconus and corneal ectasia. However, techniques for in vivo and in situ assessment of the treatment are limited. In this study, ex vivo porcine eyes were treated with a chemical CXL agent (glutaraldehyde), during which polarization sensitive optical coherence tomography (PS-OCT) recordings were acquired simultaneously to assess the sensitivity of the technique to assess changes in the cornea. The results obtained in this study suggest that PSOCT may be a suitable technique to measure CXL changes in situ and to assess the local changes in the treated region of the cornea.

  7. Descendants of the Chiral Anomaly

    OpenAIRE

    Jackiw, R.

    2000-01-01

    Chern-Simons terms are well-known descendants of chiral anomalies, when the latter are presented as total derivatives. Here I explain that also Chern-Simons terms, when defined on a 3-manifold, may be expressed as total derivatives.

  8. Polarization-sensitive optical frequency domain imaging based on unpolarized light.

    Science.gov (United States)

    Kim, Ki Hean; Park, B Hyle; Tu, Yupeng; Hasan, Tayyaba; Lee, Byunghak; Li, Jianan; de Boer, Johannes F

    2011-01-17

    Polarization-sensitive optical coherence tomography (PS-OCT) is an augmented form of OCT, providing 3D images of both tissue structure and polarization properties. We developed a new method of polarization-sensitive optical frequency domain imaging (PS-OFDI), which is based on a wavelength-swept source. In this method the sample was illuminated with unpolarized light, which was composed of two orthogonal polarization states (i.e., separated by 180° in the Poincaré sphere) that are uncorrelated to each other. Reflection of these polarization states from within the sample was detected simultaneously and independently using a frequency multiplexing scheme. This simultaneous sample probing with two polarization states enabled determination of the depth-resolved Jones matrices of the sample. Polarization properties of the sample were obtained by analyzing the sample Jones matrices through eigenvector decomposition. The new PS-OFDI system ran at 31K wavelength-scans/s with 3072 pixels per wavelength-scan, and was tested by imaging a polarizer and several birefringent tissues such as chicken muscle and human skin. Lastly the new PS-OFDI was applied to imaging two cancer animal models: a mouse model by injecting cancer cells and a hamster cheek pouch model. These animal model studies demonstrated the significant differences in tissue polarization properties between cancer and normal tissues in vivo.

  9. Depth-encoded all-fiber swept source polarization sensitive OCT

    Science.gov (United States)

    Wang, Zhao; Lee, Hsiang-Chieh; Ahsen, Osman Oguz; Lee, ByungKun; Choi, WooJhon; Potsaid, Benjamin; Liu, Jonathan; Jayaraman, Vijaysekhar; Cable, Alex; Kraus, Martin F.; Liang, Kaicheng; Hornegger, Joachim; Fujimoto, James G.

    2014-01-01

    Polarization sensitive optical coherence tomography (PS-OCT) is a functional extension of conventional OCT and can assess depth-resolved tissue birefringence in addition to intensity. Most existing PS-OCT systems are relatively complex and their clinical translation remains difficult. We present a simple and robust all-fiber PS-OCT system based on swept source technology and polarization depth-encoding. Polarization multiplexing was achieved using a polarization maintaining fiber. Polarization sensitive signals were detected using fiber based polarization beam splitters and polarization controllers were used to remove the polarization ambiguity. A simplified post-processing algorithm was proposed for speckle noise reduction relaxing the demand for phase stability. We demonstrated systems design for both ophthalmic and catheter-based PS-OCT. For ophthalmic imaging, we used an optical clock frequency doubling method to extend the imaging range of a commercially available short cavity light source to improve polarization depth-encoding. For catheter based imaging, we demonstrated 200 kHz PS-OCT imaging using a MEMS-tunable vertical cavity surface emitting laser (VCSEL) and a high speed micromotor imaging catheter. The system was demonstrated in human retina, finger and lip imaging, as well as ex vivo swine esophagus and cardiovascular imaging. The all-fiber PS-OCT is easier to implement and maintain compared to previous PS-OCT systems and can be more easily translated to clinical applications due to its robust design. PMID:25401008

  10. Polarization Sensitive Measurements of Molecular Reorientation in a Glass Capacitor Cell

    Science.gov (United States)

    Cooper, Nathan; Lawhead, Carlos; Anderson, Josiah; Shiver, Tegan; Prayaga, Chandra; Ujj, Laszlo

    2014-03-01

    It is well known that molecules having a permanent dipole moment tend to orient in the direction of the electric field at room temperature. The reorientation can be probed with the help of linear spectroscopy methods such as fluorescence anisotropy measurements. We have used nonlinear polarization sensitive Raman scattering spectroscopy to quantify the orientation effect of the dipoles. Vibrational spectra of the molecules has been recorded as a function of the external electric field. The polarization changes observed during the measurement are directly linked to the molecular reorientation rearrangement. Spectra has been recorded with a laser spectrometer comprised of a Nd:YAG laser and an optical parametric oscillator and an imaging spectrometer with a CCD detector. In order to make this measurement we have constructed a glass capacitor cell coated in TiO and applied a significant electric field (0-3 kV/mm) to the sample. Our measurements showed that the orientation effect is most significant for liquid crystals as observed previously with non-polarization sensitive CARS spectroscopy.

  11. Characterization of muscle stretching and damage using polarization-sensitive optical coherence tomography (PS-OCT)

    Science.gov (United States)

    Chen, Dongsheng; Zeng, Nan; Liu, Celong; Ma, Hui

    2012-12-01

    In this paper, we study muscle elastic drawing and damage using our lab's polarization-sensitive optical coherence tomography (PS-OCT) instrument and polarization sensitive Monte Carlo program. First, we acquire two-dimensional PS-OCT images of elastically drawn and injured muscle, injury processes including dehydration and hydrolysis, we extract some characteristics from experimental results including extinction coefficient, integral reflectivity and birefringence and so on, which will change during muscle is being elastically drawn or injured. In order to further understand and evaluate the degree of muscle elastic drawing or damage according to the measurements parameters mentioned above, we do some corresponding simulations using our lab's Monte Carlo program, which is based on a sphere cylinder birefringence model and can simulate complicated tissue containing anisotropic microstructures and various polarization imaging and measurement systems. For muscle elastic drawing, we find that integral reflectivity sometimes increases and decreases as muscle's elastic drawing continues, and through simulation we are unable to find the relationship between extinction coefficients and muscle elastic drawing. As for muscle damage, we simulate two processes: dehydration and hydrolysis. We find that as dehydration deepens, the birefringence of muscle is increasing but getting slowly and the integral reflectivity is decreasing, and as hydrolysis deepens, the birefringence decreases and the integral reflectivity decreases almost linearly. Through the analysis above, we demonstrate the validity of those parameters to characterize muscle elasticity and fiber structure and explain its potential for assessment of muscle damage.

  12. Adjustments to the MODIS Terra Radiometric Calibration and Polarization Sensitivity in the 2010 Reprocessing

    Science.gov (United States)

    Meister, Gerhard; Franz, Bryan A.

    2011-01-01

    The Moderate-Resolution Imaging Spectroradiometer (MODIS) on NASA s Earth Observing System (EOS) satellite Terra provides global coverage of top-of-atmosphere (TOA) radiances that have been successfully used for terrestrial and atmospheric research. The MODIS Terra ocean color products, however, have been compromised by an inadequate radiometric calibration at the short wavelengths. The Ocean Biology Processing Group (OBPG) at NASA has derived radiometric corrections using ocean color products from the SeaWiFS sensor as truth fields. In the R2010.0 reprocessing, these corrections have been applied to the whole mission life span of 10 years. This paper presents the corrections to the radiometric gains and to the instrument polarization sensitivity, demonstrates the improvement to the Terra ocean color products, and discusses issues that need further investigation. Although the global averages of MODIS Terra ocean color products are now in excellent agreement with those of SeaWiFS and MODIS Aqua, and image quality has been significantly improved, the large corrections applied to the radiometric calibration and polarization sensitivity require additional caution when using the data.

  13. Retinal pigment epithelium findings in patients with albinism using wide-field polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Schütze, Christopher; Ritter, Markus; Blum, Robert; Zotter, Stefan; Baumann, Bernhard; Pircher, Michael; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2014-11-01

    To investigate pigmentation characteristics of the retinal pigment epithelium (RPE) in patients with albinism using wide-field polarization-sensitive optical coherence tomography compared with intensity-based spectral domain optical coherence tomography and fundus autofluorescence imaging. Five patients (10 eyes) with previously genetically diagnosed albinism and 5 healthy control subjects (10 eyes) were imaged by a wide-field polarization-sensitive optical coherence tomography system (scan angle: 40 × 40° on the retina), sensitive to melanin contained in the RPE, based on the polarization state of backscattered light. Conventional intensity-based spectral domain optical coherence tomography and fundus autofluorescence examinations were performed. Retinal pigment epithelium-pigmentation was analyzed qualitatively and quantitatively based on depolarization assessed by polarization-sensitive optical coherence tomography. This study revealed strong evidence of polarization-sensitive optical coherence tomography to specifically image melanin in the RPE. Depolarization of light backscattered by the RPE in patients with albinism was reduced compared with normal subjects. Heterogeneous RPE-specific depolarization characteristics were observed in patients with albinism. Reduction of depolarization observed in the light backscattered by the RPE in patients with albinism corresponds to expected decrease of RPE pigmentation. The degree of depigmentation of the RPE is possibly associated with visual acuity. Findings suggest that different albinism genotypes result in heterogeneous levels of RPE pigmentation. Polarization-sensitive optical coherence tomography showed a heterogeneous appearance of RPE pigmentation in patients with albinism depending on different genotypes.

  14. Acquisition of the polarity sensitive item renhe 'any' in Mandarin Chinese.

    Science.gov (United States)

    Huang, Aijun; Crain, Stephen

    2014-07-01

    The present study investigated Mandarin-speaking children's acquisition of the polarity sensitive item renhe 'any' in Mandarin Chinese. Like its English counterpart any, renhe can be used as a negative polarity item (NPI), or as a free choice (FC) item, and both the distribution and interpretation of renhe are governed by the same syntactic and semantic constraints as English any. Using a Truth Value Judgment Task, the present study tested five-year-old Mandarin-speaking children's comprehension of FC renhe in sentences containing the modal word neng 'can', and tested children's comprehension of NPI renhe in sentences containing the temporal conjunction zai…zhiqian 'before'. Most children demonstrated knowledge of the interpretation of both FC renhe and NPI renhe despite a paucity of relevant adult input. Like adults, however, Mandarin-speaking children do not use renhe frequently in ordinary conversation, due to the availability of alternative colloquial expressions (wh-pronouns) that also convey children's intended meanings.

  15. Simple Unbiased Hot-Electron Polarization-Sensitive Near-Infrared Photodetector.

    Science.gov (United States)

    Mirzaee, Somayeh M A; Lebel, Olivier; Nunzi, Jean-Michel

    2018-03-27

    Plasmonic nanostructures can generate energetic "hot" electrons from light in a broad band fashion depending on their shape, size, and arrangement. Such structures have a promising use in photodetectors, allowing high speed, broad band, and multicolor photodetection. Because they function without a band gap absorption, photon detection at any energy would be possible through engineering of the plasmonic nanostructure. Herein, a compact hot-electron-based photodetector that combines polarization sensitivity and circularly polarized light detection in the near-infrared region was fabricated using an indium tin oxide (ITO)-Au hybrid layer. Furthermore, the sensitivity of the device was significantly increased by adding a poled Azo molecular glass film in a capacitor configuration. The resulting device is capable of detecting light below the ITO band gap at ambient temperature without any bias voltage. This photodetector, which is amenable to large-area fabrication, can be integrated with other nanophotonic and nanoplasmonic structures for operation at telecom wavelengths.

  16. Polarization sensitivity of light diffraction for periodic array of anisotropic gold nanoparticles

    International Nuclear Information System (INIS)

    Tsai, Ming-shan; Liu, Tung-kai; Tsen, Chun-yu; Ting, Chen-ching

    2015-01-01

    This article aims to analyze the first order diffraction intensity of the incident polarized light which is diffracted by the gold nanoparticles array in terms of the surface plasmon effect. The inspected gold nanoparticles array films are built in grating pattern with stripe thickness of 4 μm and diameters of gold nanoparticles ca. 10–56 nm, which are formed by annealing at temperatures of 400, 450, 500, and 550 °C, respectively. The probing light is linearly polarized with wavelengths of 450–800 nm and counterclockwise turns its polarization direction from 0° to 90° during measurements. The results show that the diffraction intensity depends on the anisotropic configuration samples which gold nanoparticles are orientated by analyzing the scanning electron microscope images. It results that the localized surface plasmon effect induced by incident field depends on orientation and causes the sample polarization-sensitive

  17. Scalable Background-Limited Polarization-Sensitive Detectors for mm-wave Applications

    Science.gov (United States)

    Rostem, Karwan; Ali, Aamir; Appel, John W.; Bennett, Charles L.; Chuss, David T.; Colazo, Felipe A.; Crowe, Erik; Denis, Kevin L.; Essinger-Hileman, Tom; Marriage, Tobias A.; hide

    2014-01-01

    We report on the status and development of polarization-sensitive detectors for millimeter-wave applications. The detectors are fabricated on single-crystal silicon, which functions as a low-loss dielectric substrate for the microwave circuitry as well as the supporting membrane for the Transition-Edge Sensor (TES) bolometers. The orthomode transducer (OMT) is realized as a symmetric structure and on-chip filters are employed to define the detection bandwidth. A hybridized integrated enclosure reduces the high-frequency THz mode set that can couple to the TES bolometers. An implementation of the detector architecture at Q-band achieves 90% efficiency in each polarization. The design is scalable in both frequency coverage, 30-300 GHz, and in number of detectors with uniform characteristics. Hence, the detectors are desirable for ground-based or space-borne instruments that require large arrays of efficient background-limited cryogenic detectors.

  18. A Low-Complexity DOA and Polarization Method of Polarization-Sensitive Array

    Directory of Open Access Journals (Sweden)

    Wen Dong

    2017-05-01

    Full Text Available This paper proposes a low-complexity method to estimate the direction of arrival and polarization based on the polarization sensitive array (PSA which is composed of cross-dipoles. We built a half-quaternions model through the Cayley–Dickson form to remove the redundant information. Then, the directions of arrival (DOAs were estimated via the root-MUSIC algorithm. Finally, the polarizations were estimated by generalized eigenvalue method. Unlike some existing searching algorithms, such as multiple signal classification (MUSIC, this method can avoid the peak searching and maintains high estimation accuracy. Moreover, we use the oblique projection operators to filter out the interference signals which are decoys of the target signal. Simulation results demonstrate the effectiveness and favorable performance of the proposed method.

  19. Fiber-Based Polarization Diversity Detection for Polarization-Sensitive Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    Hamid Pahlevaninezhad

    2014-09-01

    Full Text Available We present a new fiber-based polarization diversity detection (PDD scheme for polarization sensitive optical coherence tomography (PSOCT. This implementation uses a new custom miniaturized polarization-maintaining fiber coupler with single mode (SM fiber inputs and polarization maintaining (PM fiber outputs. The SM fiber inputs obviate matching the optical lengths of the two orthogonal OCT polarization channels prior to interference while the PM fiber outputs ensure defined orthogonal axes after interference. Advantages of this detection scheme over those with bulk optics PDD include lower cost, easier miniaturization, and more relaxed alignment and handling issues. We incorporate this PDD scheme into a galvanometer-scanned OCT system to demonstrate system calibration and PSOCT imaging of an achromatic quarter-wave plate, fingernail in vivo, and chicken breast, salmon, cow leg, and basa fish muscle samples ex vivo.

  20. Suomi National Polar-Orbiting Partnership Visible Infrared Imaging Radiometer Suite Polarization Sensitivity Analysis

    Science.gov (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Waluschka, Eugene; Wang, Menghua

    2016-01-01

    The Visible Infrared Imaging Radiometer Suite (VIIRS) is one of five instruments onboard the Suomi National Polar-Orbiting Partnership (SNPP) satellite that launched from Vandenberg Air Force Base, California, on October 28, 2011. It is a whiskbroom radiometer that provides +/-56.28deg scans of the Earth view. It has 22 bands, among which 14 are reflective solar bands (RSBs). The RSBs cover a wavelength range from 410 to 2250 nm. The RSBs of a remote sensor are usually sensitive to the polarization of incident light. For VIIRS, it is specified that the polarization factor should be smaller than 3% for 410 and 862 nm bands and 2.5% for other RSBs for the scan angle within +/-45deg. Several polarization sensitivity tests were performed prelaunch for SNPP VIIRS. The first few tests either had large uncertainty or were less reliable, while the last one was believed to provide the more accurate information about the polarization property of the instrument. In this paper, the measured data in the last polarization sensitivity test are analyzed, and the polarization factors and phase angles are derived from the measurements for all the RSBs. The derived polarization factors and phase angles are band, detector, and scan angle dependent. For near-infrared bands, they also depend on the half-angle mirror side. Nevertheless, the derived polarization factors are all within the specification, although the strong detector dependence of the polarization parameters was not expected. Compared to the Moderate Resolution Imaging Spectroradiometer on both Aqua and Terra satellites, the polarization effect on VIIRS RSB is much smaller.

  1. Asymmetric MQW semiconductor optical amplifier with low-polarization sensitivity of over 90-nm bandwidth

    Science.gov (United States)

    Nkanta, Julie E.; Maldonado-Basilio, Ramón; Abdul-Majid, Sawsan; Zhang, Jessica; Hall, Trevor J.

    2013-12-01

    An exhausted capacity of current Passive Optical Networks has been anticipated as bandwidth-hungry applications such as HDTV and 3D video become available to end-users. To enhance their performance, the next generation optical access networks have been proposed, using optical carriers allocated within the E-band (1360-1460 nm). It is partly motivated by the low-water peak fiber being manufactured by Corning. At these wavelengths, choices for low cost optical amplifiers, with compact size, low energy consumption and feasibility for integration with other optoelectronic components are limited, making the semiconductor optical amplifiers (SOA) a realistic solution. An experimental characterization of a broadband and low polarization sensitive asymmetric multi quantum well (MQW) SOA operating in the E-band is reported. The SOA device is composed of nine 6 nm In1-xGaxAsyP1-y 0.2% tensile strained asymmetric MQW layers sandwiched between nine latticed matched 6 nm InGaAsP barrier layers. The active region is grown on an n-doped InP substrate and buried by p-doped InGaAsP layers. The SOA devices have 7-degrees tilt anti-reflected coated facets, with 2 μm ridge width, and a cavity length of 900 μm. For input powers of -10 dBm and -20 dBm, a maximum gain of 20 dB at 1360 nm with a polarization insensitivity under 3 dB for over 90 nm bandwidth is measured. Polarization sensitivity of less than 0.5 dB is observed for some wavelengths. Obtained results indicate a promising SOA with broadband amplification, polarization insensitivity and high gain. These SOAs were designed and characterized at the Photonics Technology Laboratory, University of Ottawa, Canada.

  2. Descending necrotising mediastinitis: Case report

    Directory of Open Access Journals (Sweden)

    Canan Eren

    2010-12-01

    Full Text Available Descending necrotising mediastinitis is a rare but usually fatal infection. It commonly results of oropharyngeal and odontogenic infections. Complete recovery may be achieved by early diagnosis, prompt medical and surgical approach. We are reporting our desending necrotizing mediastinitis case secondary to tooth abscess, and it’s successfull surgical treatment.A-48-year-old man admitted with fever, exhaustion neck distendion for a week. He had a tooth abscess one week ago. Chest tomography showed neck and mediastinal air and fluid collections. Antibiothreapy was started and urgent surgical management applied. Neck drainage was performed via transcervical approach. Mediastinal drainage was performed via right thoracotomy. Continue mediastinal washing feasibility was done by drainage tubes. Drainage was ended after nonextra drainage and cultural growthless. Vital signs became stable and control tomography showed complete recovery. He was healthfull at the 6th month’s follow-up.Broad antibiothreapy, surgical management are the main approaches for descending necrotising mediastinitis. The most common surgical procedure is the combination of transcervical approach and thoracotomy. We suggest early and agressive surgical management for the complete recovery. J Clin Exp Invest 2010; 1(3: 228-231

  3. Polarization-Sensitive Optical Coherence Tomography Imaging of Benign and Malignant Laryngeal Lesions: An In Vivo Study

    NARCIS (Netherlands)

    Burns, J.A.; Kim, K.H.; de Boer, J.F.; Anderson, R.R.; Zeitels, S. M.

    2011-01-01

    Objective. Optical coherence tomography (OCT), an imaging technology that provides cross-sectional subsurface tissue structure images using back-scattered light, is a promising noninvasive imaging modality for in vivo assessment of vocal fold layered microstructure. Polarization-sensitive OCT

  4. Polarization-sensitive optical coherence tomography for the nondestructive assessment of the remineralization of dentin

    Science.gov (United States)

    Manesh, Saman K.; Darling, Cynthia L.; Fried, Daniel

    2009-07-01

    Previous studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to image caries lesions in dentin, measure nondestructively the severity of dentin demineralization, and determine the efficacy of intervention with anticaries agents including fluoride and lasers. The objective of this study is to determine if PS-OCT can be used to nondestructively measure a reduction in the reflectivity of dentin lesions after exposure to a remineralization solution. Although studies have shown the ability of PS-OCT to image the remineralization of lesions in enamel, none have included dentin. PS-OCT images of dentin surfaces are acquired after exposure to an artificial demineralizing solution for six days and a remineralizing solution for 20 days. The integrated reflectivity, depth of demineralization, and thickness of the layer of remineralization are calculated for each of the two treatment groups on each sample. Polarized light microscopy and microradiography are used to measure lesion severity on histological thin sections for comparison. PS-OCT successfully measured the formation of a layer of increased mineral content near the lesion surface. Polorized light microscopy (PLM) and transverse microradiography (TMR) corroborated those results. PS-OCT can be used for the nondestructive measurement of the remineralization of dentin.

  5. In vivo imaging of human burn injuries with polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Kim, Ki Hean; Pierce, Mark C.; Maguluri, Gopi; Park, B. Hyle; Yoon, Sang June; Lydon, Martha; Sheridan, Robert; de Boer, Johannes F.

    2012-06-01

    The accurate determination of burn depth is critical in the clinical management of burn wounds. Polarization-sensitive optical coherence tomography (PS-OCT) has been proposed as a potentially non-invasive method for determining burn depth by measuring thermally induced changes in the structure and birefringence of skin, and has been investigated in pre-clinical burn studies with animal models and ex vivo human skin. In this study, we applied PS-OCT to the in-vivo imaging of two pediatric burn patients. Deep and superficial burned skins along with contralateral controls were imaged in 3D. The imaging size was 8 mm×6 mm×2 mm in width, length, and depth in the air respectively, and the imaging time was approximately 6 s per volume. Superficially burned skins exhibited the same layered structure as the contralateral controls, but more visible vasculature and reduced birefringence compared to the contralateral controls. In contrast, a deeply burned skin showed loss of the layered structure, almost absent vasculature, and smaller birefringence compared to superficial burns. This study suggested the vasculature and birefringence as parameters for characterizing burn wounds.

  6. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography.

    Science.gov (United States)

    Lu, Zenghai; Kasaragod, Deepa K; Matcher, Stephen J

    2011-02-21

    We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincaré sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  7. All fiber optics circular-state swept source polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Lin, Hermann; Kao, Meng-Chun; Lai, Chih-Ming; Huang, Jyun-Cin; Kuo, Wen-Chuan

    2014-02-01

    A swept source (SS)-based circular-state (CS) polarization-sensitive optical coherence tomography (PS-OCT) constructed entirely with polarization-maintaining fiber optics components is proposed with the experimental verification. By means of the proposed calibration scheme, bulk quarter-wave plates can be replaced by fiber optics polarization controllers to, therefore, realize an all-fiber optics CS SSPS-OCT. We also present a numerical dispersion compensation method, which can not only enhance the axial resolution, but also improve the signal-to-noise ratio of the images. We demonstrate that this compact and portable CS SSPS-OCT system with an accuracy comparable to bulk optics systems requires less stringent lens alignment and can possibly serve as a technology to realize PS-OCT instrument for clinical applications (e.g., endoscopy). The largest deviations in the phase retardation (PR) and fast-axis (FA) angle due to sample probe in the linear scanning and a rotation angle smaller than 65 deg were of the same order as those in stationary probe setups. The influence of fiber bending on the measured PR and FA is also investigated. The largest deviations of the PR were 3.5 deg and the measured FA change by ~12 to 21 deg. Finally, in vivo imaging of the human fingertip and nail was successfully demonstrated with a linear scanning probe.

  8. Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography

    Energy Technology Data Exchange (ETDEWEB)

    Lu Zenghai; Kasaragod, Deepa K; Matcher, Stephen J, E-mail: z.lu@sheffield.ac.uk, E-mail: s.j.matcher@sheffield.ac.uk [Department of Materials Science and Engineering, Kroto Research Institute, University of Sheffield, North Campus, Broad Lane, Sheffield, S3 7HQ (United Kingdom)

    2011-02-21

    We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincare sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.

  9. Polarization-sensitive optical coherence tomography for imaging of biological tissues

    Science.gov (United States)

    Chen, Xiaodong; Wang, Yi; Li, Wanhui; Yu, Daoyin

    2006-09-01

    Polarization sensitive optical coherence tomography (PS-OCT) is a new non-contact and non-invasive method for measuring the change of birefringence in biological tissues caused by pathological changes of body. It has great potential in imaging the structural properties of turbid biological media because the polarization state of light backscattered from biological tissues is influenced by the birefringence of fibrous structures. The arrangement is based on a Michelson interferometer with use of quarter-wave plates and polarimeter. Through the detection of light backscattered from biological tissues and reflected from a reference mirror, the optical phase delay between orthogonal polarization compositions propagating in the birefringence media can be measured. PS-OCT is a powerful tool for research of tendon, dentin, lesions, which have strong polarization effective. We in this paper describe the experimental scheme and its mathematical representation, along with the theory of PS-OCT imaging. Besides, we introduce a fiber-based PS-OCT system for measuring the tissue birefringence.

  10. Correlation between polarization sensitive optical coherence tomography and second harmonic generation microscopy in skin.

    Science.gov (United States)

    Le, Viet-Hoan; Lee, Seunghun; Kim, Bumju; Yoon, Yeoreum; Yoon, Calvin J; Chung, Wan Kyun; Kim, Ki Hean

    2015-07-01

    Both polarization sensitive optical coherence tomography (PS-OCT) and second harmonic generation (SHG) microscopy are 3D optical imaging methods providing information related to collagen in the skin. PS-OCT provides birefringence information which is due to the collagen composition of the skin. SHG microscopy visualizes collagen fibers in the skin based on their SHG property. These two modalities have been applied to the same skin pathologies associated with collagen changes, but their relationship has not been examined. In this study, we tried to find the relationship by imaging the same skin samples with both modalities. Various parts of the normal rat skin and burn damaged skin were imaged ex vivo, and their images were analyzed both qualitatively and quantitatively. PS-OCT images were analyzed to obtain tissue birefringence. SHG images were analyzed to obtain collagen orientation indices by applying 2D Fourier transform. The skin samples having higher birefringence values had higher collagen orientation indices, and a linear correlation was found between them. Burn damaged skin showed decreases in both parameters compared to the control skins. This relationship between the bulk and microscopic properties of skin may be useful for further skin studies.

  11. The hand-hold polarization-sensitive spectral domain optical coherence and its applications

    Science.gov (United States)

    Liu, Hao; Gao, Wanrong

    2017-08-01

    The polarization-sensitive spectral domain optical coherence tomography (PSOCT) has the advantages of being able to measure the polarization properties of samples, such as phase-retardation, diattenuation, depolarization, and optical axis orientation, providing a contrast to identify the diseased area and normal area in tissues in PSOCT images. Conventionally, the sample arm of PSOCT is fixed on the stage where biomedical tissues or models is placed, and the OCT images is acquired by scanning with a galvanometer-based mirror. To be applied in the practical diagnosis, a promising way is to design a hand-held device. To this end, it is required that probe is assembled with a small volume to allow for comprehensively imaging large tissues areas at a microscopic scale, and is available to move on different samples to be acquired quickly with negligible motion artifacts. Meanwhile, the probe should be manufactured wih well stability to avoid system jitter error while it is used to detect the biological tissues in vivo. In this work, a design of a hand-hold fiber-based PSOCT is described. The device is of the size of 10 cm (length) × 8 cm (width) × 6 cm (height). Both the axial resolution and the imaging depth of the system are measured and were approximately 7 μm and 2.5 mm in air, respectively, which are in good agreement with the theoretical predictions. The A-scan rate of the system is 70 kHz. The structure is compact and all the components are fixed on the shell to reduce the motion artifact, resulting in a great stability on measuring the tissues in vivo. The cross sectional images of ex vivo chicken breast, ex vivo pork cartilage and in vivo forearm skin of human wolunteer are presented to demonstrate the capability of the system.

  12. Nano-particle doped hydroxyapatite material evaluation using spectroscopic polarization sensitive optical coherence tomography

    Science.gov (United States)

    Strąkowska, Paulina; Trojanowski, Michał; Gardas, Mateusz; Głowacki, Maciej J.; Kraszewski, Maciej; Strąkowski, Marcin R.

    2015-03-01

    Bio-ceramics such as hydroxyapatite (HAp) are widely used materials in medical applications, especially as an interface between implants and living tissues. There are many ways of creating structures from HAp like electrochemical assisted deposition, biomimetic, electrophoresis, pulsed laser deposition or sol-gel processing. Our research is based on analyzing the parameters of the sol-gel method for creating thin layers of HAp. In order to achieve this, we propose to use Optical Coherence Tomography (OCT) for non-destructive and non-invasive evaluation. Our system works in the IR spectrum range, which is helpful due to the wide range of nanocomposites being opaque in the VIS range. In order to use our method we need to measure two samples, one which is a reference HAp solution and second: a similar HAp solution with nanoparticles introduced inside. We use silver nanoparticles below 300 nm. The aim of this research is to analyze the concentration and dispersion of nanodopants in the bio-ceramic matrix. Furthermore, the quality of the HAp coating and deposition process repetition have been monitored. For this purpose the polarization sensitive OCT with additional spectroscopic analysis is being investigated. Despite the other methods, which are suitable for nanocomposite materials evaluation, the OCT with additional features seems to be one of the few which belong to the NDE/NDT group. Here we are presenting the OCT system for evaluation of the HAp with nano-particles, as well as HAp manufacturing process. A brief discussion on the usefulness of OCT for bio-ceramics materials examination is also being presented.

  13. Accurate and quantitative polarization-sensitive OCT by unbiased birefringence estimator with noise-stochastic correction

    Science.gov (United States)

    Kasaragod, Deepa; Sugiyama, Satoshi; Ikuno, Yasushi; Alonso-Caneiro, David; Yamanari, Masahiro; Fukuda, Shinichi; Oshika, Tetsuro; Hong, Young-Joo; Li, En; Makita, Shuichi; Miura, Masahiro; Yasuno, Yoshiaki

    2016-03-01

    Polarization sensitive optical coherence tomography (PS-OCT) is a functional extension of OCT that contrasts the polarization properties of tissues. It has been applied to ophthalmology, cardiology, etc. Proper quantitative imaging is required for a widespread clinical utility. However, the conventional method of averaging to improve the signal to noise ratio (SNR) and the contrast of the phase retardation (or birefringence) images introduce a noise bias offset from the true value. This bias reduces the effectiveness of birefringence contrast for a quantitative study. Although coherent averaging of Jones matrix tomography has been widely utilized and has improved the image quality, the fundamental limitation of nonlinear dependency of phase retardation and birefringence to the SNR was not overcome. So the birefringence obtained by PS-OCT was still not accurate for a quantitative imaging. The nonlinear effect of SNR to phase retardation and birefringence measurement was previously formulated in detail for a Jones matrix OCT (JM-OCT) [1]. Based on this, we had developed a maximum a-posteriori (MAP) estimator and quantitative birefringence imaging was demonstrated [2]. However, this first version of estimator had a theoretical shortcoming. It did not take into account the stochastic nature of SNR of OCT signal. In this paper, we present an improved version of the MAP estimator which takes into account the stochastic property of SNR. This estimator uses a probability distribution function (PDF) of true local retardation, which is proportional to birefringence, under a specific set of measurements of the birefringence and SNR. The PDF was pre-computed by a Monte-Carlo (MC) simulation based on the mathematical model of JM-OCT before the measurement. A comparison between this new MAP estimator, our previous MAP estimator [2], and the standard mean estimator is presented. The comparisons are performed both by numerical simulation and in vivo measurements of anterior and

  14. Enhanced monolithic diffraction gratings with high efficiency and reduced polarization sensitivity for remote sensing applications

    Science.gov (United States)

    Triebel, Peter; Diehl, Torsten; Moeller, Tobias; Gatto, Alexandre; Pesch, Alexander; Erdmann, Lars H.; Burkhardt, Matthias; Kalies, Alexander

    2015-10-01

    distribution. Beside of the results of straylight measurement the actual results on improving efficiency and lowering the polarization sensitivity for transmission gratings will be discussed on theoretical simulations compared to measured data over the entire wavelength range.

  15. Descending necrotizing mediastinitis: surgical management.

    Science.gov (United States)

    Papalia, E; Rena, O; Oliaro, A; Cavallo, A; Giobbe, R; Casadio, C; Maggi, G; Mancuso, M

    2001-10-01

    Descending necrotizing mediastinitis (DNM) is a primary complication of cervical or odontogenical infections that can spread to the mediastinum through the anatomic cervical spaces. Between April 1994 and April 2000, 13 patients, mean age 39.23+/-18.47 (median 38, range 16-67) years, with DNM were submitted to surgical treatment. Primary odontogenic abscess occurred in six, peritonsillar abscess in five and post-traumatic cervical abscess in two patients. Diagnosis was confirmed by computed tomography (CT) of the neck and chest. All patients underwent surgical drainage of the cervico-mediastinal regions by a bilateral collar incision associated with right thoracotomy in ten cases. Six patients out of 13 required reoperation. Two patients previously submitted only to cervical drainage required thoracotomy; four patients, which have been submitted to cervico-thoracic drainage, underwent contralateral thoracotomy in two cases and ipsilateral reoperation in two cases. Ten patients evolved well and were discharged without major sequelae; three patients died of multiorgan failure related to septic shock. Mortality rate was 23%. Early diagnosis by CT of the neck and chest suggest a rapid indication of surgical approach to DNM. Ample cervicotomy associated with mediastinal drainage via large thoracotomic incision is essential in managing these critically ill patients and can significantly reduce the mortality rate for this condition, often affecting young people, to acceptable values.

  16. Single input state, single–mode fiber–based polarization sensitive optical frequency domain imaging by eigenpolarization referencing

    Science.gov (United States)

    Lippok, Norman; Villiger, Martin; Jun, Chang–Su; Bouma, Brett E.

    2015-01-01

    Fiber–based polarization sensitive OFDI is more challenging than free–space implementations. Using multiple input states, fiber–based systems provide sample birefringence information with the benefit of a flexible sample arm but come at the cost of increased system and acquisition complexity, and either reduce acquisition speed or require increased acquisition bandwidth. Here we show that with the calibration of a single polarization state, fiber–based configurations can approach the conceptual simplicity of traditional free–space configurations. We remotely control the polarization state of the light incident at the sample using the eigenpolarization states of a wave plate as a reference, and determine the Jones matrix of the output fiber. We demonstrate this method for polarization sensitive imaging of biological samples. PMID:25927775

  17. Retinal processing and opponent mechanisms mediating ultraviolet polarization sensitivity in rainbow trout (Oncorhynchus mykiss)

    NARCIS (Netherlands)

    Ramsden, Samuel D.; Anderson, Leslie; Mussi, Martina; Kamermans, Maarten; Hawryshyn, Craig W.

    2008-01-01

    A number of teleost fishes have photoreceptor mechanisms to detect linearly polarized light. We studied the neuronal mechanism underlying this ability. It was found that a polarized signal could be detected in rainbow trout (Oncorhynchus mykiss) both in the electroretinogram (ERG) and in the

  18. Polarization sensitive changes in the human macula associated with normal aging and age-related macular degeneration

    Science.gov (United States)

    VanNasdale, Dean Allan, Jr.

    2011-12-01

    The human macula occupies a relatively small, but crucial retinal area, as it is the location responsible for our most acute spatial vision and best color discrimination. Localizing important landmarks in the retina is difficult even in normal eyes where morphological inter-individual variability is high. This becomes even more challenging in the presence of sight-threatening pathology. With respect to the human macula, there remains a significant gap in the understanding of normal structure and function. Even less is known about the pathological mechanisms that occur in sight-threatening diseases including age-related macular degeneration. Because relatively little is known about normal aging changes, it is also difficult to differentiate those changes from changes associated with retinal disease. To better understand normal and pathological changes in the macula, imaging techniques using specific optical signatures are required. Structural features in the macula can be distinguished based on their intrinsic properties using specific light/tissue interactions. Because of the high degree of structural regularity in the macula, polarization sensitive imaging is potentially a useful tool for evaluating the morphology and integrity of the cellular architecture for both normal individuals and those affected by disease. In our investigations, we used polarization sensitive imaging to determining normal landmarks that are important clinically and for research investigations. We found that precision and accuracy in localizing the central macula was greatly improved through the use of polarization sensitive imaging. We also found that specific polarization alterations can be used to demonstrate systematic changes as a function of age, disproportionately affecting the central macular region. When evaluating patients with age-related macular degeneration, we found that precision and accuracy of localizing the central macula was also improved, even when significant pathology

  19. Polarity-sensitive nanocarrier for oral delivery of Sb(V and treatment of cutaneous leishmaniasis

    Directory of Open Access Journals (Sweden)

    Lanza JS

    2016-05-01

    remarkable property of these nanoassemblies, as revealed by AFM analysis, is the flexibility of their supramolecular organization, which showed changes as a function of the solvent and substrate polarities. The formulation of SbL8 in 1:1 water:PG given orally to mice promoted significantly higher and more sustained serum levels of Sb, when compared to SbL8 in water. The new formulation, when given as repeated doses (200 mg Sb/kg/day to BALB/c mice infected with Leishmania amazonensis, was significantly more effective in reducing the lesion parasite burden, compared to SbL8 in water, and even, the conventional drug Glucantime® given intraperitoneally at the same dose. In conclusion, this work introduces a new concept of polarity-sensitive nanocarrier that was successfully applied to optimize an oral formulation of Sb(V for treating cutaneous leishmaniasis. Keywords: propylene glycol, antimony, Leishmania amazonensis, AFM, amphiphilic complex, SAXS

  20. Polarization sensitive optical coherence tomography at 1060 nm for retinal imaging

    International Nuclear Information System (INIS)

    Torzicky, T.

    2014-01-01

    The aim of this thesis was to develop a Polarization Sensitive Optical Coherence Tomography (PS-OCT) device for ocular imaging in the 1 µm wavelength range and to explore its capabilities to image healthy subjects and patients with various retinal disorders. PS-OCT set-ups working in the 840 nm range have been used in several clinical studies, for examining different retinal pathologies. Especially the segmentation of the retinal pigment epithelium (RPE) based on PS-OCT data shows advantages in cases of age related macular degeneration (AMD) in comparison to segmentation based on intensity images from commercial OCT systems. OCT imaging in the 1 µm wavelength region has recently gained popularity for ophthalmic applications due to the fact that it is perfectly suitable for enhanced visualization of choroid and sclera. This is due to decreased scattering and absorption in the RPE with increasing wavelength and due to the local absorption minimum of water (the vitreous of the eye consists mainly of water) for wavelengths around 1060 nm. An additional advantage is that a higher imaging quality in patients with corneal haze or cataract can be achieved when using OCT systems working at 1 µm. In this work we combine the advantages of PS-OCT imaging with the enhanced penetration depth of the 1 µm wavelength range for acquiring intensity, retardation, axis orientation and degree of polarization uniformity (DOPU) images of choroid and sclera. As a first step different PS-OCT set-ups working at 1060 nm were developed and a comparison regarding set-up parameters and imaging performance was accomplished. The two different set-ups that were built and investigated were a spectrometer based Fourier Domain OCT set-up and a swept source Fourier Domain OCT set-up. The swept source set-up was tested with two different light sources, a commercially available swept source laser (A-Scan rate of 100 kHz) and a prototype of a Fourier Domain Mode Locked (FDML) laser (A-Scan rate of 350

  1. A descendent relation in genus 2

    OpenAIRE

    Belorousski, Pasha; Pandharipande, Rahul

    1998-01-01

    A new codimension 2 relation among descendent strata in the moduli space of stable, 3-pointed, genus 2 curves is found. The space of pointed admissible double covers is used in the calculation. The resulting differential equations satisfied by the genus 2 gravitational potentials of varieties in Gromov-Witten theory are described. These are analogous to the WDVV-equations in genus 0 and Getzler's equations in genus 1. As an application, genus 2 descendent invariants of the projective plane ar...

  2. Automated Identification and Quantification of Subretinal Fibrosis in Neovascular Age-Related Macular Degeneration Using Polarization-Sensitive OCT.

    Science.gov (United States)

    Roberts, Philipp; Sugita, Mitsuro; Deák, Gábor; Baumann, Bernhard; Zotter, Stefan; Pircher, Michael; Sacu, Stefan; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2016-04-01

    To identify and quantify subretinal fibrosis in eyes with advanced neovascular age-related macular degeneration (nAMD) using polarization-sensitive optical coherence tomography (PS-OCT). Eyes of patients with subretinal fibrosis secondary to nAMD were included in this case series. All patients underwent a complete ophthalmic examination to clearly identify advanced nAMD lesions with fibrosis. Examinations of PS-OCT were performed using a novel system with an integrated eye tracker. Areas of fibrosis in PS-OCT, automatically segmented using a custom-built algorithm, were compared with conventional imaging modalities including spectral-domain OCT, fluorescein angiography, and color fundus photography in their potential to visualize fibrosis in nAMD. Fifteen eyes of 15 consecutive patients were included. In polarization-sensitive OCT B-scans, a distinct "column-like" pattern was observed in averaged axis orientation images. En face analysis provided a precise mapping of the fibrotic scar component. Fibrous tissue was selectively identified by PS-OCT based on birefringence in all lesions, whereas in SD-OCT, subretinal hyperreflective material (SHRM) could not be further classified into scar tissue, fibrovascular material, or other AMD-specific material. Based on simultaneous polarization analyses in PS-OCT, the level of RPE alteration could be evaluated as well, showing thinning and loss of RPE associated with subretinal fibrosis. Using PS-OCT, subretinal fibrosis can be identified as an intrinsically birefringent structure and can be segmented based solely on tissue-specific contrast. Polarization-sensitive OCT offers a unique method to identify clinically relevant components of SHRM (i.e., neovascular tissue versus fibrous tissue) and therefore allows for an optimized disease management and evaluation of therapeutic strategies.

  3. LCD panel characterization by measuring full Jones matrix of individual pixels using polarization-sensitive digital holographic microscopy.

    Science.gov (United States)

    Park, Jongchan; Yu, Hyeonseung; Park, Jung-Hoon; Park, YongKeun

    2014-10-06

    We present measurements of the full Jones matrix of individual pixels in a liquid-crystal display (LCD) panel. Employing a polarization-sensitive digital holographic microscopy based on Mach-Zehnder interferometry, the complex amplitudes of the light passing through individual LCD pixels are precisely measured with respect to orthogonal bases of polarization states, from which the full Jones matrix components of individual pixels are obtained. We also measure the changes in the Jones matrix of individual LCD pixels with respect to an applied bias. In addition, the complex optical responses of a LCD panel with respect to arbitrary polarization states of incident light were characterized from the measured Jones matrix.

  4. Intersubband absorption in annealed InAs/GaAs quantum dots: a case for polarization-sensitive infrared detection

    International Nuclear Information System (INIS)

    Chakrabarti, S; Bhattacharya, P; Stiff-Roberts, A D; Lin, Y Y; Singh, J; Lei, Y; Browning, N

    2003-01-01

    We have studied the characteristics of intersubband absorption of polarized infrared (IR) radiation in as-grown and annealed self-organized InAs/GaAs quantum dots. It is observed that with the increase of annealing time and temperature, the dots tend to flatten and behave more like quantum wells. As a result, their sensitivity to TE (in-plane)-polarized light decreases and that to TM (out-of-plane)-polarized light increases. The effect could be utilized for the realization of polarization-sensitive IR detectors

  5. d-PET-controlled “off-on” Polarity-sensitive Probes for Reporting Local Hydrophilicity within Lysosomes

    Science.gov (United States)

    Zhu, Hao; Fan, Jiangli; Mu, Huiying; Zhu, Tao; Zhang, Zhen; Du, Jianjun; Peng, Xiaojun

    2016-10-01

    Polarity-sensitive fluorescent probes are powerful chemical tools for studying biomolecular structures and activities both in vitro and in vivo. However, the lack of “off-on” polarity-sensing probes has limited the accurate monitoring of biological processes that involve an increase in local hydrophilicity. Here, we design and synthesize a series of “off-on” polarity-sensitive fluorescent probes BP series consisting of the difluoroboron dippyomethene (BODIPY) fluorophore connected to a quaternary ammonium moiety via different carbon linkers. All these probes showed low fluorescence quantum yields in nonpolar solution but became highly fluorescent in polar media. BP-2, which contains a two-carbon linker and a trimethyl quaternary ammonium, displayed a fluorescence intensity and quantum yield that were both linearly correlated with solvent polarity. In addition, BP-2 exhibited high sensitivity and selectivity for polarity over other environmental factors and a variety of biologically relevant species. BP-2 can be synthesized readily via an unusual Mannich reaction followed by methylation. Using electrochemistry combined with theoretical calculations, we demonstrated that the “off-on” sensing behavior of BP-2 is primarily due to the polarity-dependent donor-excited photoinduced electron transfer (d-PET) effect. Live-cell imaging established that BP-2 enables the detection of local hydrophilicity within lysosomes under conditions of lysosomal dysfunction.

  6. Descending necrotizing mediastinitis in the elderly patients

    Directory of Open Access Journals (Sweden)

    Mazzella Antonio

    2016-01-01

    Full Text Available Descending Necrotizing Mediastinitis (DNM is a polymicrobic, dangerous and often fatal process, arising from head or neck infections and spreading along the deep fascial cervical planes, descending into the mediastinum. It can rapidly progress to sepsis and can frequently lead to death. It has a high mortality rate, up to 40% in the different series, as described in the literature. Surgical and therapeutic management has been discussed for long time especially in an elderly patient population. The literature has been reviewed in order to evaluate different pathogenesis and evolution and to recognise a correct therapeutic management.

  7. Diversity of Cortico-descending Projections

    DEFF Research Database (Denmark)

    Innocenti, Giorgio M; Caminiti, Roberto; Rouiller, Eric M

    2018-01-01

    The axonal composition of cortical projections originating in premotor, supplementary motor (SMA), primary motor (a4), somatosensory and parietal areas and descending towards the brain stem and spinal cord was characterized in the monkey with histological tract tracing, electron microscopy (EM) a...

  8. Segmentation and quantification of retinal lesions in age-related macular degeneration using polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Baumann, Bernhard; Gotzinger, Erich; Pircher, Michael; Sattmann, Harald; Schuutze, Christopher; Schlanitz, Ferdinand; Ahlers, Christian; Schmidt-Erfurth, Ursula; Hitzenberger, Christoph K

    2010-01-01

    We present polarization-sensitive optical coherence tomography (PS-OCT) for quantitative assessment of retinal pathologies in age-related macular degeneration (AMD). On the basis of the polarization scrambling characteristics of the retinal pigment epithelium, novel segmentation algorithms were developed that allow one to segment pathologic features such as drusen and atrophic zones in dry AMD as well as to determine their dimensions. Results from measurements in the eyes of AMD patients prove the ability of PS-OCT for quantitative imaging based on the retinal features polarizing properties. Repeatability measurements were performed in retinas diagnosed with drusen and geographic atrophy in order to evaluate the performance of the described methods. PS-OCT appears as a promising imaging modality for three-dimensional retinal imaging and ranging with additional contrast based on the structures' tissue-inherent polarization properties.

  9. Measurement of Collagen and Smooth Muscle Cell Content in Atherosclerotic Plaques Using Polarization-Sensitive Optical Coherence Tomography

    Science.gov (United States)

    Nadkarni, Seemantini K.; Pierce, Mark C.; Park, B. Hyle; de Boer, Johannes F.; Whittaker, Peter; Bouma, Brett E.; Bressner, Jason E.; Halpern, Elkan; Houser, Stuart L.; Tearney, Guillermo J.

    2009-01-01

    Objectives The purpose of this study was to investigate the measurement of collagen and smooth muscle cell (SMC) content in atherosclerotic plaques using polarization-sensitive optical coherence tomography (PSOCT). Background A method capable of evaluating plaque collagen content and SMC density can provide a measure of the mechanical fidelity of the fibrous cap and can enable the identification of high-risk lesions. Optical coherence tomography has been demonstrated to provide cross-sectional images of tissue microstructure with a resolution of 10 µm. A recently developed technique, PSOCT measures birefringence, a material property that is elevated in tissues such as collagen and SMCs. Methods We acquired PSOCT images of 87 aortic plaques obtained from 20 human cadavers. Spatially averaged PSOCT birefringence, Φ, was measured and compared with plaque collagen and SMC content, quantified morphometrically by picrosirius red and smooth muscle actin staining at the corresponding locations. Results There was a high positive correlation between PSOCT measurements of Φ and total collagen content in all plaques (r = 0.67, p < 0.001) and in fibrous caps of necrotic core fibroatheromas (r = 0.68, p < 0.001). Polarization-sensitive optical coherence tomography measurements of Φ demonstrated a strong positive correlation with thick collagen fiber content (r = 0.76, p < 0.001) and SMC density (r = 0.74, p < 0.01). Conclusions Our results demonstrate that PSOCT enables the measurement of birefringence in plaques and in fibrous caps of necrotic core fibroatheromas. Given its potential to evaluate collagen content, collagen fiber thickness, and SMC density, we anticipate that PSOCT will significantly improve our ability to evaluate plaque stability in patients. PMID:17397678

  10. Suicide awareness of japanese family descendants

    Directory of Open Access Journals (Sweden)

    Carla Tiemi Kawaziri Diogo

    2014-10-01

    Full Text Available This study aimed to comprehend the meaning of suicide for Japanese descendants. This was a qualitative study, based on Grounded Theory, using a structured interview with sixteen questions, digitally recorded. Subjects were ten descendants who were interviewed in 2011. The opinions of the interviewed showed factors of psychological, social and cultural origin involved in suicide, such as: heredity, religion, mental health, personality characteristics and interpersonal relationships, pleasure and pain at work, stigma and consequences of the act on the family. Family without case of suicide showed attitudes of prejudice and judgment, while those with case displayed feelings of pain in their reports. It was concluded that the Japanese rigid culture, personality, interpersonal communication and the way family and work have effects on their behavior are predisposing factors to suicide, as well as the identification of these factors contributes to a better performance of the nurse.

  11. Retinal polarization-sensitive optical coherence tomography at 1060 nm with 350 kHz A-scan rate using an Fourier domain mode locked laser

    DEFF Research Database (Denmark)

    Torzicky, Teresa; Marschall, Sebastian; Pircher, Michael

    2013-01-01

    We present a novel, high-speed, polarization-sensitive, optical coherence tomography set-up for retinal imaging operating at a central wavelength of 1060 nm which was tested for in vivo imaging in healthy human volunteers. We use the system in combination with a Fourier domain mode locked laser...

  12. Collateralization of the pathways descending from the cerebral cortex to brain stem and spinal cord in cat and monkey

    NARCIS (Netherlands)

    K. Keizer (Koos)

    1989-01-01

    textabstractThe present study deals with the collateralization of the descending pathways from the cerebral cortex to the brain stem and the spinal cord in cat and monkey. The distributions of the branching cortical neurons were studied using retrograde fluorescent tracers. In addition, a new

  13. Quantifying the optical properties and chromophore concentrations of turbid media using polarization sensitive hyperspectral imaging: optical phantom studies

    Science.gov (United States)

    Vasefi, Fartash; Saager, Rolf; Durkin, Anthony J.; MacKinnon, Nicholas; Gussakovsky, Eugene; Chave, Robert; Farkas, Daniel L.

    2013-02-01

    We present a polarization-sensitive hyperspectral imaging system (SkinSpect) that employs a spectrally-programmable light source in the visible and NIR domains. Multiple tissue-mimicking phantoms were fabricated to mimic the optical properties of normal skin as well as pigmented light and dark moles. The phantoms consist of titanium dioxide and a mixture of coffee, red food dye, and naphthol green as the scattering and the three absorptive agents in a polydimethylsiloxane (PDMS) base. Phantoms were produced with both smooth and rough textured surfaces and tested using Spatial Frequency Domain Imaging (SFDI) and Spatially Modulated Quantitative Spectroscopy (SMoQS) for homogeneity as well as determining absorption and scattering variance, respectively. The reflectance spectral images were also recorded using the SkinSpect research prototype; the spectral signatures of the phantoms were calculated using a two-flux single-layer Kubelka-Munk model and non-negative least square fitting routine was applied to extract the relative concentrations of the individual phantom components.

  14. Light polarization sensitive photodetectors with m- and r-plane homoepitaxial ZnO/ZnMgO quantum wells

    Energy Technology Data Exchange (ETDEWEB)

    Tabares, G.; Hierro, A., E-mail: adrian.hierro@upm.es; Lopez-Ponce, M.; Muñoz, E. [ISOM and Dpto. Ingeniería Electrónica, Universidad Politécnica de Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Vinter, B.; Chauveau, J.-M. [CRHEA-CNRS, Av. B. Gregory, 06560 Valbonne (France); University of Nice Sophia Antipolis, Parc Valrose, 06102 Nice cedex 2 (France)

    2015-02-09

    Homoepitaxial ZnO/(Zn,Mg)O multiple quantum wells (MQWs) grown with m- and r-plane orientations are used to demonstrate Schottky photodiodes sensitive to the polarization state of light. In both orientations, the spectral photoresponse of the MQW photodiodes shows a sharp excitonic absorption edge at 3.48 eV with a very low Urbach tail, allowing the observation of the absorption from the A, B and C excitonic transitions. The absorption edge energy is shifted by ∼30 and ∼15 meV for the m- and r-plane MQW photodiodes, respectively, in full agreement with the calculated polarization of the A, B, and C excitonic transitions. The best figures of merit are obtained for the m-plane photodiodes, which present a quantum efficiency of ∼11%, and a specific detectivity D* of ∼6.4 × 10{sup 10} cm Hz{sup 1/2}/W. In these photodiodes, the absorption polarization sensitivity contrast between the two orthogonal in-plane axes yields a maximum value of (R{sub ⊥}/R{sub ||}){sub max} ∼ 9.9 with a narrow bandwidth of ∼33 meV.

  15. Investigation of acid-etched CO2 laser ablated enamel surfaces using polarization sensitive optical coherence tomography

    Science.gov (United States)

    Nahm, Byung J.; Kang, Hobin; Chan, Kenneth; Fried, Daniel

    2012-01-01

    A carbon dioxide laser operating at the highly absorbed wavelength of 9.3μm with a pulse duration of 10-15μs is ideally suited for caries removal and caries prevention. The enamel thermally modified by the laser has enhanced resistance to acid dissolution. This is an obvious advantage for caries prevention; however, it is often necessary to etch the enamel surface to increase adhesion to composite restorative materials and such surfaces may be more resistant to etching. The purpose of the study was to non-destructively measure the susceptibility of laser-ablated enamel surfaces to acid dissolution before and after acid-etching using Polarization Sensitive Optical Coherence Tomography (PS-OCT). PS-OCT was used to acquire images of bovine enamel surfaces after exposure to laser irradiation at ablative fluence, acid-etching, and a surface softened dissolution model. The integrated reflectivity from lesion and the lesion depth were measured using PS-OCT. Samples were also sectioned for examination by Polarized Light Microscopy (PLM). PS-OCT images showed that acid-etching greatly accelerated the formation of subsurface lesions on both laser-irradiated and non-irradiated surfaces (Plaser modified enamel layer after 5-10 seconds.

  16. Development of an polarization sensitive Fourier domain optical coherence tomography and it utilization on the Mueller matrix determination

    International Nuclear Information System (INIS)

    Raele, Marcus Paulo

    2009-01-01

    This study approached theoretical and experimental aspects related with the development of a polarization sensitive, Fourier domain, optical coherence tomography system (PS-FD-OCT) and its utilization on the Mueller Matrix determination. This work began with a bibliographic revision, which describes since the early studies to the actual state of the art of the technique. The mathematical formalism of Fourier domain low coherence interferometry and light polarization was performed as well. Studies based on numerical simulations, of three different algorithm types, responsible to recover the scattering profile, were done. The implemented algorithms were: Direct Fourier Transform, Interpolation and zero-filling. By the end of the simulation study, was possible to conclude that the algorithm zero-filling 2N presented better characteristics when compared with the others. In the experimental part, firstly different OCT setups were assembled and measurements were done in order to verify aspects related with the theory. Then, using a polymeric sample, birefringence images were performed, which allowed determining the sample birefringence quantitatively. Finally, images taken of different polarization states were collected, and through then images related with the Mueller Matrix elements were calculated, which were analyzed individually. (author)

  17. Assessment of vascularization and myelination following peripheral nerve repair using angiographic and polarization sensitive optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Nam, Ahhyun S.; Chico-Calero, Isabel; Easow, Jeena M.; Villiger, Martin; Welt, Jonathan; Winograd, Jonathan M.; Randolph, Mark A.; Redmond, Robert W.; Vakoc, Benjamin J.

    2017-02-01

    A severe traumatic injury to a peripheral nerve often requires surgical graft repair. However, functional recovery after these surgical repairs is often unsatisfactory. To improve interventional procedures, it is important to understand the regeneration of the nerve grafts. The rodent sciatic nerve is commonly used to investigate these parameters. However, the ability to longitudinally assess the reinnervation of injured nerves are limited, and to our knowledge, no methods currently exist to investigate the timing of the revascularization in functional recovery. In this work, we describe the development and use of angiographic and polarization-sensitive (PS) optical coherence tomography (OCT) to visualize the vascularization, demyelination and remyelination of peripheral nerve healing after crush and transection injuries, and across a variety of graft repair methods. A microscope was customized to provide 3.6 cm fields of view along the nerve axis with a capability to track the nerve height to maintain the nerve within the focal plane. Motion artifact rejection was implemented in the angiography algorithm to reduce degradation by bulk respiratory motion in the hindlimb site. Vectorial birefringence imaging methods were developed to significantly enhance the accuracy of myelination measurements and to discriminate birefringent contributions from the myelin and epineurium. These results demonstrate that the OCT platform has the potential to reveal new insights in preclinical studies and may ultimately provide a means for clinical intra-surgical assessment of peripheral nerve function.

  18. Anisotropic percolation conduction in elastomer-carbon black composites investigated by polarization-sensitive terahertz time-domain spectroscopy

    Science.gov (United States)

    Okano, Makoto; Fujii, Misako; Watanabe, Shinichi

    2017-11-01

    We investigated the draw ratio (DR) dependence of the anisotropic dielectric function and conductivity of styrene butadiene rubbers (SBRs) with different carbon black (CB) concentrations by polarization-sensitive terahertz time-domain spectroscopy. From the frequency dependence of the conductivity in the unstretched SBRs ranging from direct current to terahertz frequencies, it is found that the SBR with a CB concentration above 30 wt. % exhibits percolation conductivity. We investigated the spectral shape of the dielectric function and conductivity of the SBR samples below and above the percolation threshold for two representative DRs in the terahertz frequency region. We found that the DR dependence of the spectral shape is well explained by the effective medium approximation, except for the sample with the CB concentration above 30 wt. % under the unstretched condition. The conductivity in that sample remarkably changes in the low terahertz frequency region, which suggests a change in the CB network by deformation. The investigation of the dielectric anisotropy and percolation conductivity using our polarization technique can be applied to a wide range of elastomer composites.

  19. Demonstration of polarization sensitivity of emulsion-based pair conversion telescope for cosmic gamma-ray polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Ozaki, Keita, E-mail: ozaki@radix.h.kobe-u.ac.jp [Kobe University, 3-11, Tsurukabuto, Nada-ku, Kobe 657-8501 (Japan); Takahashi, Satoru, E-mail: satoru@radix.h.kobe-u.ac.jp [Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Aoki, Shigeki; Kamada, Keiki; Kaneyama, Taichi; Nakagawa, Ryo; Rokujo, Hiroki [Kobe University, 3-11, Tsurukabuto, Nada-ku, Kobe 657-8501 (Japan)

    2016-10-11

    Linear polarization of high-energy gamma-rays (10MeV–100 GeV) can be detected by measuring the azimuthal angle of electron–positron pairs and observing the modulation of the azimuthal distribution. To demonstrate the gamma-ray polarization sensitivity of emulsion, we conducted a test using a polarized gamma-ray beam (0.8–2.4 GeV) at SPring-8/LEPS. Emulsion tracks were reconstructed using scanning data, and gamma-ray events were selected automatically. Using an optical microscope, out of the 2381 gamma-ray conversions that were observed, 1372 remained after event selection, on the azimuthal angle distribution of which we measured the modulation. From the distribution of the azimuthal angles of the selected events, a modulation factor of 0.21+0.11−0.09 was measured, from which the detection of a non-zero modulation was established with a significance of 3.06σ. This attractive polarimeter will be applied to the GRAINE project, a balloon-borne experiment that observes 10–100 GeV cosmic gamma-rays with an emulsion-based pair conversion telescope.

  20. Polarization sensitive subcutaneous and muscular imaging based on common path optical coherence tomography using near infrared source.

    Science.gov (United States)

    Han, Jae-Ho; Kang, Jin U; Song, Chul Gyu

    2011-08-01

    In this paper, we describe a polarization sensitive (PS) subcutaneous and muscular imaging system based on common path optical coherence tomography (CP-OCT) using a near infrared source. The axial and lateral resolutions of the PS-OCT system are 9 and 6 μm, respectively. The main goal of this work is to build a high-resolution and minimally invasive optical imager for examining various kinds of cutaneous substructures with intrinsic or form birefringence. The internal structural information is extracted by the real-time signal analysis (Fourier Transform) of the modulated spectral intensity depending on the beam and tissue birefringence. The preliminary results using fresh beef longissimus muscle and in vivo Rattus norvegicus (rat) show that it is possible to visualize the birefringence effect of the tissue collagen fibers in the samples in order to achieve superior image contrast and sensitivity for the detection of hidden dermal structures. Compared to conventional CP-OCT, the proposed PS-OCT system provides depth-resolved images, which reflect the tissue birefringence.

  1. Descending serotonergic facilitation and the antinociceptive effects of pregabalin in a rat model of osteoarthritic pain

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    Dolphin Annette C

    2009-08-01

    Full Text Available Abstract Background Descending facilitation, from the brainstem, promotes spinal neuronal hyperexcitability and behavioural hypersensitivity in many chronic pain states. We have previously demonstrated enhanced descending facilitation onto dorsal horn neurones in a neuropathic pain model, and shown this to enable the analgesic effectiveness of gabapentin. Here we have tested if this hypothesis applies to other pain states by using a combination of approaches in a rat model of osteoarthritis (OA to ascertain if 1 a role for descending 5HT mediated facilitation exists, and 2 if pregabalin (a newer analogue of gabapentin is an effective antinociceptive agent in this model. Further, quantitative-PCR experiments were undertaken to analyse the α2δ-1 and 5-HT3A subunit mRNA levels in L3–6 DRG in order to assess whether changes in these molecular substrates have a bearing on the pharmacological effects of ondansetron and pregabalin in OA. Results Osteoarthritis was induced via intra-articular injection of monosodium iodoacetate (MIA into the knee joint. Control animals were injected with 0.9% saline. Two weeks later in vivo electrophysiology was performed, comparing the effects of spinal ondansetron (10–100 μg/50 μl or systemic pregabalin (0.3 – 10 mg/kg on evoked responses of dorsal horn neurones to electrical, mechanical and thermal stimuli in MIA or control rats. In MIA rats, ondansetron significantly inhibited the evoked responses to both innocuous and noxious natural evoked neuronal responses, whereas only inhibition of noxious evoked responses was seen in controls. Pregabalin significantly inhibited neuronal responses in the MIA rats only; this effect was blocked by a pre-administration of spinal ondansetron. Analysis of α2δ-1 and 5-HT3A subunit mRNA levels in L3–6 DRG revealed a significant increase in α2δ-1 levels in ipsilateral L3&4 DRG in MIA rats. 5-HT3A subunit mRNA levels were unchanged. Conclusion These data suggest

  2. Descending necrotizing mediastinitis of oropharyngeal infections

    Directory of Open Access Journals (Sweden)

    Mohsen Sokouti

    2009-09-01

    Full Text Available Background and aims. Descending necrotizing mediastinitis (DNM is a rare and life-threatening infection. Management of this condition is very difficult and before 1990s, DNM had a mortality rate of 40% despite the use of antibiotics. One of the etiologies of this condition is rapid downward spread of oropharyngeal infection along the cervical fascia planes into the mediastinum. Materials and methods. Patients with DNM from odontogenic, peritonsillar and retropharyngeal origins, who underwent surgical treatment from 1990 to 2007, were reviewed. Data extracted from medical records of the patients included age, gender, origin of the infection, surgical approaches, and the cause of mortality. Descriptive data were expressed as a Mean ± SE. Results. Thirteen patients aged 15 to 56 (mean, 34.5 years old; 8 males and 5 females were studied. The origins of infection included odontogenic abscess in 10 cases and peritonsillar and retropharyngeal abscess in 3 patients. The mean duration from onset of symptoms to the surgery was 12.18 ± 0.98 days (range 3 to 24 days and the mean duration from initial surgery to discharges was 28.51 ± 3.25 days (range 5 to 92 days. Post-operative mortality was seen in three patients. Conclusion. Descending necrotizing mediastinitis can arise from odontogenic abscesses and must be detected as early as possible, as it is a life-threatening infection.

  3. Multifunctional in vivo imaging for monitoring wound healing using swept-source polarization-sensitive optical coherence tomography.

    Science.gov (United States)

    Park, Kwan S; Choi, Woo June; Song, Shaozhen; Xu, Jingjiang; Wang, Ruikang K

    2017-11-30

    Wound healing involves a complex and dynamic biological process in response to tissue injury. Monitoring of the cascade of cellular events is useful for wound management and treatment. The aim of this study is to demonstrate the potential of multifunctional polarization-sensitive optical coherence tomography (PS-OCT) to longitudinally monitor the self-healing process in a murine cutaneous wound model. A multi-functional PS-OCT system based on swept source OCT configuration (1,310 nm central wavelength) was designed to obtain simultaneously microstructural, blood perfusion, and birefringent information of a biological tissue in vivo. A 1-mm-diameter wound was generated in a mouse pinna with a complete biopsy punch. Afterwards, the self-healing process of the injured tissue was observed every week over 6-week period using the multifunctional system to measure changes in the tissue birefringence. Further OCT angiography (OCTA) was used in post data processing to obtain blood perfusion information over the injured tissue. Three complementary images indicating the changes in anatomical, vascular, and birefringent information of tissue around wound were simultaneously provided from a 3-dimensional (3-D) PS-OCT data set during the wound repair over 1 month. Specifically, inflammatory and proliferative phases of wound healing were characterized by thickened epidermal tissue (from OCT images) and angiogenesis (from OCT angiography images) around wound. Also, it was observed that the regenerating tissues had highly realigned birefringent structures (from PS-OCT images). This preliminary study suggests that the proposed multi-functional imaging modality has a great potential to improve the understanding of wound healing through non-invasive, serial monitoring of vascular and tissue responses to injury. Lasers Surg. Med. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  4. Polarization-Sensitive Optical Coherence Tomographic Documentation of Choroidal Melanin Loss in Chronic Vogt-Koyanagi-Harada Disease.

    Science.gov (United States)

    Miura, Masahiro; Makita, Shuichi; Yasuno, Yoshiaki; Tsukahara, Rintaro; Usui, Yoshihiko; Rao, Narsing A; Ikuno, Yasushi; Uematsu, Sato; Agawa, Tetsuya; Iwasaki, Takuya; Goto, Hiroshi

    2017-09-01

    Vogt-Koyanagi-Harada (VKH) disease is a systemic autoimmune disorder that affects organs with melanocytes. The sunset glow fundus (SGF) in VKH disease was evaluated with polarization-sensitive optical coherence tomography (PS-OCT). The study involved 28 eyes from 14 patients with chronic VKH disease, 21 eyes from 21 age-matched controls, and 22 eyes from 22 high-myopic patients with a tessellated fundus. VKH eyes were grouped into sunset or non-sunset groups on the basis of color fundus images. The presence of melanin in the choroid was determined by using the degree of polarization uniformity (DOPU) obtained by PS-OCT. The sunset glow index (SGI) was calculated by using color fundus images. Presence of an SGF was evaluated by using DOPU, SGI, subfoveal choroidal thicknesses, near-infrared images, and autofluorescence images at 488 nm (SW-AF) and 785 nm (NIR-AF). There were 16 eyes in the sunset group and 12 eyes in the non-sunset group. For all eyes in the sunset group, the disappearance of choroidal melanin was clearly detected with PS-OCT. Percentage areas of low DOPU in the choroidal interstitial stroma of the sunset group were significantly lower than those of other groups and showed no overlap with other groups. The distribution of choroidal thicknesses and SGI in the sunset group substantially overlapped with other groups. The subjective analyses of the sunset and non-sunset groups, using near infrared, SW-AF, or NIR-AF, showed substantial inconsistencies with the PS-OCT results. PS-OCT provides an in vivo objective evaluation of choroidal melanin loss of the SGF in chronic VKH disease.

  5. Analysis of the Origin of Atypical Scanning Laser Polarimetry Patterns by Polarization-Sensitive Optical Coherence Tomography

    Science.gov (United States)

    Götzinger, Erich; Pircher, Michael; Baumann, Bernhard; Hirn, Cornelia; Vass, Clemens; Hitzenberger, Christoph K.

    2010-01-01

    Purpose To analyze the physical origin of atypical scanning laser polarimetry (SLP) patterns. To compare polarization-sensitive optical coherence tomography (PS-OCT) scans to SLP images. To present a method to obtain pseudo-SLP images by PS-OCT that are free of atypical artifacts. Methods Forty-one eyes of healthy subjects, subjects with suspected glaucoma, and patients with glaucoma were imaged by SLP (GDx VCC) and a prototype spectral domain PS-OCT system. The PS-OCT system acquires three-dimensional (3D) datasets of intensity, retardation, and optic axis orientation simultaneously within 3 seconds. B-scans of intensity and retardation and en face maps of retinal nerve fiber layer (RNFL) retardation were derived from the 3D PS-OCT datasets. Results were compared with those obtained by SLP. Results Twenty-two eyes showed atypical retardation patterns, and 19 eyes showed normal patterns. From the 22 atypical eyes, 15 showed atypical patterns in both imaging modalities, five were atypical only in SLP images, and two were atypical only in PS-OCT images. In most (15 of 22) atypical cases, an increased penetration of the probing beam into the birefringent sclera was identified as the source of atypical patterns. In such cases, the artifacts could be eliminated in PS-OCT images by depth segmentation and exclusion of scleral signals. Conclusions PS-OCT provides deeper insight into the contribution of different fundus layers to SLP images. Increased light penetration into the sclera can distort SLP retardation patterns of the RNFL. PMID:19036999

  6. Lesion size detection in geographic atrophy by polarization-sensitive optical coherence tomography and correlation to conventional imaging techniques.

    Science.gov (United States)

    Schütze, Christopher; Bolz, Matthias; Sayegh, Ramzi; Baumann, Bernhard; Pircher, Michael; Götzinger, Erich; Hitzenberger, Christoph K; Schmidt-Erfurth, Ursula

    2013-01-28

    To investigate the reproducibility of automated lesion size detection in patients with geographic atrophy (GA) using polarization-sensitive spectral-domain optical coherence tomography (PS-OCT) and to compare findings with scanning laser ophthalmoscopy (SLO), fundus autofluorescence (FAF), and intensity-based spectral-domain OCT (SD-OCT). Twenty-nine eyes of 22 patients with GA were examined by PS-OCT, selectively identifying the retinal pigment epithelium (RPE). A novel segmentation algorithm was applied, automatically detecting and quantifying areas of RPE atrophy. The reproducibility of the algorithm was assessed, and lesion sizes were correlated with manually delineated SLO, FAF, and intensity-based SD-OCT images to validate the clinical applicability of PS-OCT in GA evaluation. Mean GA lesion size of all patients was 5.28 mm(2) (SD: 4.92) in PS-OCT. Mean variability of individual repeatability measurements was 0.83 mm(2) (minimum: 0.05; maximum: 3.65). Mean coefficient of variation was 0.07 (min: 0.01; max: 0.19). Mean GA area in SLO (Spectralis OCT) was 5.15 mm(2) (SD: 4.72) and 2.5% smaller than in PS-OCT (P = 0.9, Pearson correlation coefficient = 0.98, P < 0.01). Mean GA area in intensity-based SD-OCT pseudo-SLO images (Cirrus OCT) was 5.14 mm(2) (SD: 4.67) and 2.7% smaller than in PS-OCT (P = 0.9, Pearson correlation coefficient = 0.98, P < 0.01). Mean GA area of all eyes measured 5.41 mm(2) (SD: 4.75) in FAF, deviating by 2.4% from PS-OCT results (P = 0.89, Pearson correlation coefficient = 0.99, P < 0.01). PS-OCT demonstrated high reproducibility of GA lesion size determination. Results correlated well with SLO, FAF, and intensity-based SD-OCT fundus imaging. PS-OCT may therefore be a valuable and specific imaging modality for automated GA lesion size determination in scientific studies and clinical practice.

  7. Descending projections arising from the parafascicular nucleus in rats: trajectory of fibers, projection pattern and mapping of terminations.

    Science.gov (United States)

    Marini, G; Pianca, L; Tredici, G

    1999-01-01

    The organization of the descending projections from the intralaminar parafascicular nucleus was studied using biocytin as an anterograde tracer in rats. After biocytin injection into the lateral parafascicular nucleus, three bundles of fibers descending throughout the brainstem were seen. Terminal fields were found in several structures, for example the lateral geniculate nucleus, nucleus reticularis thalami, subthalamus, zona incerta, substantia nigra, red nucleus, periaqueductal gray, superior colliculus, reticular formation, raphe nuclei, pontine nuclei, trigeminal complex, and ventral horn of the spinal cord. Different types of labeled terminals (small terminal boutons, en passant varicosities, large claw-like terminals) were observed, particularly in the substantia nigra and reticular formation where the density of terminals was highest. The organization of these extensive descending connections to both motor and sensory structures does not allow functions to be conclusively attributed to the parafascicular nucleus neurons. Further investigations are required to resolve this question.

  8. Inverted Lymphoglandular Polyp in Descending Colon

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    Shengmei Zhou

    2015-01-01

    Full Text Available A 47-year-old male with a history of left colon cancer, status post left colon resection for 12 years, presented with rectal bleeding. Colonoscopic examination revealed an 8 mm sessile polyp in the proximal descending colon. Microscopic examination showed that the surface of this polyp was covered with a layer of normal colonic mucosa with focal surface erosion. In the submucosal layer, an intimate admixture of multiple cystically dilated glands and prominent lymphoid aggregates with germinal centers was seen. The glands were lined by columnar epithelium. Immunohistochemical staining showed the glands were positive for CK20 and CDX2 and negative for CK7, with a low proliferative index, mostly consistent with reactive colonic glands. The patient remained asymptomatic after one-year follow-up. A review of the literature shows very rare descriptions of similar lesions, but none fits exactly this pattern. We would designate this inverted lymphoglandular polyp and present this case to raise the awareness of recognizing this unusual histological entity.

  9. The intramyocardial left anterior descending artery: Prevalence and ...

    African Journals Online (AJOL)

    The intramyocardial left anterior descending artery: Prevalence and surgical considerations in coronary artery bypass grafting. ... The left anterior descending (LAD) artery is the most commonly bridged vessel. Its prevalence ... Techniques are described to address this anatomical variation when it is encountered at surgery.

  10. A combinatorial approach for analyzing the number of descendants ...

    African Journals Online (AJOL)

    This work is devoted to a study of the number of descendants of node j in random increasing trees, previously treated in [5, 8, 10, 15], and also to a study of the number of descendants of node j in pairs of random trees generated by a certain growth process generalizing the corresponding analysis of various classes of ...

  11. Neuroplasticity of ascending and descending pathways after somatosensory system injury: reviewing knowledge to identify neuropathic pain therapeutic targets.

    Science.gov (United States)

    Boadas-Vaello, P; Castany, S; Homs, J; Álvarez-Pérez, B; Deulofeu, M; Verdú, E

    2016-05-01

    This is a narrative review of the literature. This review aims to be useful in identifying therapeutic targets. It focuses on the molecular and biochemical neuroplasticity changes that occur in the somatosensory system, including ascending and descending pathways, during the development of neuropathic pain. Furthermore, it highlights the latest experimental strategies, based on the changes reported in the damaged nociceptive neurons during neuropathic pain states. This study was conducted in Girona, Catalonia, Spain. A MEDLINE search was performed using the following terms: descending pain pathways; ascending pain pathways; central sensitization; molecular pain; and neuropathic pain pharmacological treatment. Neuropathic pain triggered by traumatic lesions leads to sensitization and hyperexcitability of nociceptors and projection neurons of the dorsal horn, a strengthening in the descendent excitatory pathway and an inhibition of the descending inhibitory pathway of pain. These functional events are associated with molecular plastic changes such as overexpression of voltage-gated ion channels, algogen-sensitive receptors and synthesis of several neurotransmitters. Molecular studies on the plastic changes in the nociceptive somatosensory system enable the development of new pharmacological treatments against neuropathic pain, with higher specificity and effectiveness than classical drug treatments. Although research efforts have already focused on these aspects, additional research may be necessary to further explore the potential therapeutic targets in neuropathic pain involved in the neuroplasticity changes of neuropathological pathways from the injured somatosensory system.

  12. A Computational Model of a Descending Mechanosensory Pathway Involved in Active Tactile Sensing.

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    Jan M Ache

    2015-07-01

    Full Text Available Many animals, including humans, rely on active tactile sensing to explore the environment and negotiate obstacles, especially in the dark. Here, we model a descending neural pathway that mediates short-latency proprioceptive information from a tactile sensor on the head to thoracic neural networks. We studied the nocturnal stick insect Carausius morosus, a model organism for the study of adaptive locomotion, including tactually mediated reaching movements. Like mammals, insects need to move their tactile sensors for probing the environment. Cues about sensor position and motion are therefore crucial for the spatial localization of tactile contacts and the coordination of fast, adaptive motor responses. Our model explains how proprioceptive information about motion and position of the antennae, the main tactile sensors in insects, can be encoded by a single type of mechanosensory afferents. Moreover, it explains how this information is integrated and mediated to thoracic neural networks by a diverse population of descending interneurons (DINs. First, we quantified responses of a DIN population to changes in antennal position, motion and direction of movement. Using principal component (PC analysis, we find that only two PCs account for a large fraction of the variance in the DIN response properties. We call the two-dimensional space spanned by these PCs 'coding-space' because it captures essential features of the entire DIN population. Second, we model the mechanoreceptive input elements of this descending pathway, a population of proprioceptive mechanosensory hairs monitoring deflection of the antennal joints. Finally, we propose a computational framework that can model the response properties of all important DIN types, using the hair field model as its only input. This DIN model is validated by comparison of tuning characteristics, and by mapping the modelled neurons into the two-dimensional coding-space of the real DIN population. This

  13. Interictal dysfunction of a brainstem descending modulatory center in migraine patients.

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    Eric A Moulton

    Full Text Available The brainstem contains descending circuitry that can modulate nociceptive processing (neural signals associated with pain in the dorsal horn of the spinal cord and the medullary dorsal horn. In migraineurs, abnormal brainstem function during attacks suggest that dysfunction of descending modulation may facilitate migraine attacks, either by reducing descending inhibition or increasing facilitation. To determine whether a brainstem dysfunction could play a role in facilitating migraine attacks, we measured brainstem function in migraineurs when they were not having an attack (i.e. the interictal phase.Using fMRI (functional magnetic resonance imaging, we mapped brainstem activity to heat stimuli in 12 episodic migraine patients during the interictal phase. Separate scans were collected to measure responses to 41 degrees C and noxious heat (pain threshold+1 degrees C. Stimuli were either applied to the forehead on the affected side (as reported during an attack or the dorsum of the hand. This was repeated in 12 age-gender-matched control subjects, and the side tested corresponded to that in the matched migraine patients. Nucleus cuneiformis (NCF, a component of brainstem pain modulatory circuits, appears to be hypofunctional in migraineurs. 3 out of the 4 thermal stimulus conditions showed significantly greater NCF activation in control subjects than the migraine patients.Altered descending modulation has been postulated to contribute to migraine, leading to loss of inhibition or enhanced facilitation resulting in hyperexcitability of trigeminovascular neurons. NCF function could potentially serve as a diagnostic measure in migraine patients, even when not experiencing an attack. This has important implications for the evaluation of therapies for migraine.

  14. Symptomatic Type IV Dual Left Anterior Descending Coronary Artery

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    Kyriacos Papadopoulos MD

    2016-12-01

    Full Text Available Dual left anterior descending coronary artery is a rare congenital anomaly with 4 subtypes. Double left anterior descending coronary artery originating from the left main stem and the right coronary artery (type IV dual left anterior descending artery has been reported to occur in 0.01% to 0.7% of patients undergoing cardiac catheterization. We report a case of a 49-year-old woman who was found to have this anomaly during coronary angiography. The patient had been complaining of chest pain that mimics angina pectoris and exercise tolerance test was positive for myocardial ischemia.

  15. Life courses of immigrants and their descendants. Doctoral thesis

    NARCIS (Netherlands)

    Kleinepier, T.

    2016-01-01

    Zijn proefschrift is getiteld 'Life courses of immigrants and their descendants', een onderzoek naar hoe jongeren van diverse etnische herkomstgroepen in Nederland de transitie naar volwassenheid maken, waarbij voornamelijk is gekeken naar gebeurtenissen in hun familie- en gezinsleven. Academic and

  16. Origins of descending projections to the medulla oblongata and rostral medulla spinalis in the urodele Salamandra salamandra (amphibia).

    Science.gov (United States)

    Naujoks-Manteuffel, C; Manteuffel, G

    1988-07-08

    Descending projections to the medulla oblongata and rostral medulla spinalis have been examined in the urodele Salamandra salamandra with retrograde horseradish peroxidase tracing. Ipsilateral projections originate from the striatum and the nucleus ventrolateralis thalami and reach the medulla oblongata. The ipsilateral nucleus praeopticus magnocellularis reaches the medulla spinalis. The rostral part of the nucleus tuberculi posterioris projects to the ipsilateral medulla oblongata; its caudal part projects further caudally. Tectal efferents and the efferents of the nucleus praetectalis profundus project bilaterally, the nucleus praetectalis superficialis, nucleus mesencephalicus nervi trigemini, torus semicircularis, nucleus Darkschewitsch, and nucleus fasciculi longitudinalis medialis project ipsilaterally to the medulla oblongata. The nucleus mesencephalicus nervi trigemini, nucleus fasciculi longitudinalis medialis, and tectal efferents reach the rostral medulla spinalis. The nucleus ruber projects mainly via the contralateral dorsolateral funiculus to the medulla spinalis. A largely crossed medullary projection arises in the nucleus dorsalis tegmenti pars anterior, a bilateral projection arises in the nucleus dorsalis tegmenti pars posterior, and an ipsilateral projection arises in the nucleus ventralis tegmenti pars anterior. Cerebellar and statoacoustic efferents descend to the medulla spinalis. The nucleus reticularis isthmi, superior, medius and inferior as well as the nucleus raphes exhibit spinal trajectories. The nucleus vestibularis magnocellularis projects bilaterally, the nucleus vestibularis medialis projects ipsilaterally spinalward. The supposed nucleus descendens nervi trigemini descends mainly contralaterally. A small spinal projection arises in the nucleus tractus solitarii. The results indicate that salamander brains display elaborate descending connections which are similar to those in other vertebrates despite their scarcely differentiated

  17. Descending colon endometriosis misdiagnosis as diverticulitis: A case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hyun; Kim, Min Jeong; Ha, Hong Il; Lee, Kwan Seop; Min, Soo Kee [Hallym University Sacred Heart Hospital, Hallym University College of Medicine, Anyang (Korea, Republic of)

    2016-09-15

    Endometriosis is defined as the presence of ectopic endometrial tissue outside the uterus. It is a common disease in menstruating females and intestinal involvement is not uncommon. Intestinal endometriosis most commonly involves the sigmoid colon, rectum, ileum, appendix, and cecum. However, the descending colon is a rare site of intestinal endometriosis. Although computed tomography (CT) findings of bowel endometriosis have been presented in several articles, there has been no report describing the CT findings of descending colon endometriosis above the pelvic cavity. Here, we report a rare case of descending colon endometriosis located in the retroperitoneal space, in which the initial impression was acute colonic diverticulitis with a small abscess on preoperative multidetector CT.

  18. Descending colon endometriosis misdiagnosis as diverticulitis: A case report

    International Nuclear Information System (INIS)

    Kim, Ji Hyun; Kim, Min Jeong; Ha, Hong Il; Lee, Kwan Seop; Min, Soo Kee

    2016-01-01

    Endometriosis is defined as the presence of ectopic endometrial tissue outside the uterus. It is a common disease in menstruating females and intestinal involvement is not uncommon. Intestinal endometriosis most commonly involves the sigmoid colon, rectum, ileum, appendix, and cecum. However, the descending colon is a rare site of intestinal endometriosis. Although computed tomography (CT) findings of bowel endometriosis have been presented in several articles, there has been no report describing the CT findings of descending colon endometriosis above the pelvic cavity. Here, we report a rare case of descending colon endometriosis located in the retroperitoneal space, in which the initial impression was acute colonic diverticulitis with a small abscess on preoperative multidetector CT

  19. Central terminal sensitization of TRPV1 by descending serotonergic facilitation modulates chronic pain.

    Science.gov (United States)

    Kim, Yu Shin; Chu, Yuxia; Han, Liang; Li, Man; Li, Zhe; LaVinka, Pamela Colleen; Sun, Shuohao; Tang, Zongxiang; Park, Kyoungsook; Caterina, Michael J; Ren, Ke; Dubner, Ronald; Wei, Feng; Dong, Xinzhong

    2014-02-19

    The peripheral terminals of primary nociceptive neurons play an essential role in pain detection mediated by membrane receptors like TRPV1, a molecular sensor of heat and capsaicin. However, the contribution of central terminal TRPV1 in the dorsal horn to chronic pain has not been investigated directly. Combining primary sensory neuron-specific GCaMP3 imaging with a trigeminal neuropathic pain model, we detected robust neuronal hyperactivity in injured and uninjured nerves in the skin, soma in trigeminal ganglion, and central terminals in the spinal trigeminal nucleus. Extensive TRPV1 hyperactivity was observed in central terminals innervating all dorsal horn laminae. The central terminal TRPV1 sensitization was maintained by descending serotonergic (5-HT) input from the brainstem. Central blockade of TRPV1 or 5-HT/5-HT3A receptors attenuated central terminal sensitization, excitatory primary afferent inputs, and mechanical hyperalgesia in the territories of injured and uninjured nerves. Our results reveal central mechanisms facilitating central terminal sensitization underlying chronic pain. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Electroacupuncture Potentiates Cannabinoid Receptor-Mediated Descending Inhibitory Control in a Mouse Model of Knee Osteoarthritis

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    Xiao-Cui Yuan

    2018-04-01

    Full Text Available Knee osteoarthritis (KOA is a highly prevalent, chronic joint disorder, which can lead to chronic pain. Although electroacupuncture (EA is effective in relieving chronic pain in the clinic, the involved mechanisms remain unclear. Reduced diffuse noxius inhibitory controls (DNIC function is associated with chronic pain and may be related to the action of endocannabinoids. In the present study, we determined whether EA may potentiate cannabinoid receptor-mediated descending inhibitory control and inhibit chronic pain in a mouse model of KOA. We found that the optimized parameters of EA inhibiting chronic pain were the low frequency and high intensity (2 Hz + 1 mA. EA reversed the reduced expression of CB1 receptors and the 2-arachidonoylglycerol (2-AG level in the midbrain in chronic pain. Microinjection of the CB1 receptor antagonist AM251 into the ventrolateral periaqueductal gray (vlPAG can reversed the EA effect on pain hypersensitivity and DNIC function. In addition, CB1 receptors on GABAergic but not glutamatergic neurons are involved in the EA effect on DNIC function and descending inhibitory control of 5-HT in the medulla, thus inhibiting chronic pain. Our data suggest that endocannabinoid (2-AG-CB1R-GABA-5-HT may be a novel signaling pathway involved in the effect of EA improving DNIC function and inhibiting chronic pain.

  1. Ascending Midbrain Dopaminergic Axons Require Descending GAD65 Axon Fascicles for Normal Pathfinding

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    Claudia Marcela Garcia-Peña

    2014-06-01

    Full Text Available The Nigrostriatal pathway (NSP is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold.

  2. Spanish language teaching and afro-descendant identity

    Directory of Open Access Journals (Sweden)

    Lidia Ester Cuba Vega

    2014-08-01

    Full Text Available There is no question about the role of education in the struggle against racism and for racial equality. However, schools still underachieve in the construction of cultural and social paradigms that allow to break with racial stereotypes and their treatment. What happens in Cuba, a country where there is no institutionalized racism and which promotes equality among all its citizens? What happens in Cuban schools regarding language teaching and race issues? How do afro-descendant teachers of Spanish assume this reality? By answering these questions, the present article is aimed at providing an approximation to the teaching of Spanish as a second language in Cuba from the perspective of afro-descendant teachers. Starting from the concepts of racial and ethnic identity and afro-descendant, the article presents the results of data collected among afro-descendant university teachers of Spanish in Cuba who give their viewpoints on several topics, including the use in their lessons of lear-ning materials which deal with African descent and race issues.

  3. Resection and anastomosis of the descending colon in 43 horses.

    Science.gov (United States)

    Prange, Timo; Holcombe, Susan J; Brown, Jennifer A; Dechant, Julie E; Fubini, Susan L; Embertson, Rolf M; Peroni, John; Rakestraw, Peter C; Hauptman, Joe G

    2010-08-01

    To determine (1) the short- (to hospital discharge) and long- (>6 months) term survival, (2) factors associated with short-term survival, and (3) the perioperative course for horses with resection and anastomosis of the descending colon. Multicentered case series. Horses (n=43) that had descending colon resection and anastomosis. Medical records (January 1995-June 2009) of 7 equine referral hospitals were reviewed for horses that had descending colon resection and anastomosis and were recovered from anesthesia. Retrieved data included history, results of clinical and clinicopathologic examinations, surgical findings, postsurgical treatment and complications, and short-term survival (hospital discharge). Long-term survival was defined as survival > or =6 months after hospital discharge. Of 43 horses, 36 (84%) were discharged from the hospital. Twenty-eight of 30 horses with follow-up information survived > or =6 months. No significant associations between perioperative factors and short-term survival were identified. Lesions included strangulating lipoma (n=27), postfoaling trauma (4), infarction (4), intraluminal obstruction (2), and other (6). Common postoperative complications included fever and diarrhea. During hospitalization 7 horses were euthanatized or died because of septic peritonitis (3), endotoxemia (3), and colic and ileus (1). Descending colon resection and anastomosis has a favorable prognosis for hospital discharge and survival > or =6 months. The most common cause of small colon incarceration was strangulating lipoma. Complications include postoperative fever and diarrhea but the prognosis is good after small colon resection and anastomosis.

  4. CASE REPORT Dual (type IV) left anterior descending artery

    African Journals Online (AJOL)

    about 1.38%. [1,3] This anomaly is seen relatively often with congenital malformations such as complete transposition of the great arteries and tetralogy of Fallot.[2]. When a short or hypoplastic LAD is detected, a differential diagnosis should be sought. There may be a long dominant posterior descending branch of the RCA, ...

  5. A definition of descendants at one point in graph calculus

    OpenAIRE

    Shadrin, Sergey

    2007-01-01

    We study the genus expansion of Barannikov-Kontsevich solutions of the WDVV equation. In terms of the related graph calculus, we give a definition of descendants at one point and prove that this definition satisfies the topological recursion relations in genera 0, 1, and 2, string and dilaton equations, and the pull-back formula.

  6. Entanglement entropy for descendent local operators in 2D CFTs

    International Nuclear Information System (INIS)

    Chen, Bin; Guo, Wu-Zhong; He, Song; Wu, Jie-qiang

    2015-01-01

    We mainly study the Rényi entropy and entanglement entropy of the states locally excited by the descendent operators in two dimensional conformal field theories (CFTs). In rational CFTs, we prove that the increase of entanglement entropy and Rényi entropy for a class of descendent operators, which are generated by L (−) L̄ (−) onto the primary operator, always coincide with the logarithmic of quantum dimension of the corresponding primary operator. That means the Rényi entropy and entanglement entropy for these descendent operators are the same as the ones of their corresponding primary operator. For 2D rational CFTs with a boundary, we confirm that the Rényi entropy always coincides with the logarithmic of quantum dimension of the primary operator during some periods of the evolution. Furthermore, we consider more general descendent operators generated by ∑d {n i }{n j } (∏ i L −n i ∏ j L̄ −n j ) on the primary operator. For these operators, the entanglement entropy and Rényi entropy get additional corrections, as the mixing of holomorphic and anti-holomorphic Virasoro generators enhance the entanglement. Finally, we employ perturbative CFT techniques to evaluate the Rényi entropy of the excited operators in deformed CFT. The Rényi and entanglement entropies are increased, and get contributions not only from local excited operators but also from global deformation of the theory.

  7. In vivo polarization-sensitive optical coherence tomography of human burn scars: birefringence quantification and correspondence with histologically determined collagen density

    Science.gov (United States)

    Jaspers, Mariëlle E. H.; Feroldi, Fabio; Vlig, Marcel; de Boer, Johannes F.; van Zuijlen, Paul P. M.

    2017-12-01

    Obtaining adequate information on scar characteristics is important for monitoring their evolution and the effectiveness of clinical treatment. The aberrant type of collagen in scars may give rise to specific birefringent properties, which can be determined using polarization-sensitive optical coherence tomography (PS-OCT). The aim of this pilot study was to evaluate a method to quantify the birefringence of the scanned volume and correlate it with the collagen density as measured from histological slides. Five human burn scars were measured in vivo using a handheld probe and custom-made PS-OCT system. The local retardation caused by the tissue birefringence was extracted using the Jones formalism. To compare the samples, histograms of birefringence values of each volume were produced. After imaging, punch biopsies were harvested from the scar area of interest and sent in for histological evaluation using Herovici polychrome staining. Two-dimensional en face maps showed higher birefringence in scars compared to healthy skin. The Pearson's correlation coefficient for the collagen density as measured by histology versus the measured birefringence was calculated at r=0.80 (p=0.105). In conclusion, the custom-made PS-OCT system was capable of in vivo imaging and quantifying the birefringence of human burn scars, and a nonsignificant correlation between PS-OCT birefringence and histological collagen density was found.

  8. Aerosol characteristics in Phimai, Thailand determined by continuous observation with a polarization sensitive Mie–Raman lidar and a sky radiometer

    International Nuclear Information System (INIS)

    Sugimoto, Nobuo; Shimizu, Atsushi; Nishizawa, Tomoaki; Matsui, Ichiro; Jin, Yoshitaka; Khatri, Pradeep; Irie, Hitoshi; Takamura, Tamio; Aoki, Kazuma; Thana, Boossarasiri

    2015-01-01

    Distributions and optical characteristics of aerosols were continuously observed with a polarization-sensitive (532 nm), Mie-scattering (532 and 1064 nm) and Raman-scattering (607 nm) lidar and a sky radiometer in Phimai, Thailand. Polarization lidar measurements indicated that high concentration plumes of spherical aerosols considered as biomass burning smoke were often observed in the dry season. Plumes of non-spherical aerosols considered as long-range transported soil dust from Africa, the Middle East, or Northeast Asia were occasionally observed. Furthermore, low-concentration non-spherical aerosols were almost always observed in the atmospheric mixing layer. Extinction coefficient profiles of spherical aerosols and non-spherical dust exhibited different diurnal variations, and spherical aerosols including smoke were distributed in higher altitudes in the mixing layer and residual layer. The difference can be explained by hygroscopic growth of smoke particles and buoyancy of the smoke. Analysis of seasonal variations of optical properties derived from the Raman lidar and the sky radiometer confirmed that the lidar ratio, aerosol optical depth, and Angstrom exponent were higher in the dry season (October–May) and lower in the wet season (June–September). The single scattering albedo was lower in the dry season. These seasonal variations are explained by frequent biomass burning in the dry season consistent with previous studies in Southeast Asian region. At the same time, the present work confirmed that soil dust was a major aerosol component in Phimai, Thailand. (letter)

  9. Simultaneous in situ measurements of properties of particulates in rf silane plasmas using a polarization-sensitive laser-light-scattering method

    Science.gov (United States)

    Shiratani, Masaharu; Kawasaki, Hiroharu; Fukuzawa, Tsuyoshi; Yoshioka, Takashi; Ueda, Yoshio; Singh, Sanjay; Watanabe, Yukio

    1996-01-01

    A polarization-sensitive laser-light-scattering method is developed for simultaneous in situ measurements of properties (size, size dispersion, density, and refractive index) of particulates formed in processing plasmas. The developed system is applied to observe the growth processes of particulates in a range of their size larger than about 10 nm in rf silane plasmas. A size, a size dispersion (logarithm of a standard deviation of size), a density, and a refractive index of particulates in the plasmas are found to be 10-200 nm, about 0.1, 107-109 cm-3 and about 3-5i, respectively. The former three of such values agree fairly well with ones deduced from scanning electron microscopic (SEM) observation. These particulates grow through three phases of nucleation and initial growth, rapid growth, and growth saturation. Coexistence of two size groups of particulates with narrow size dispersions during and after the rapid growth phase verified by the SEM observation may be explained by a model taking into account coagulation between oppositely charged particulates.

  10. Facial height in Japanese-Brazilian descendants with normal occlusion

    Science.gov (United States)

    Vieira, Fabiano Paiva; Pinzan, Arnaldo; Janson, Guilherme; Fernandes, Thais Maria Freire; Sathler, Renata Carvalho; Henriques, Rafael Pinelli

    2014-01-01

    OBJECTIVE: The aim of this study was to determine the standards of facial height in 30 young (14-year-old) Japanese-Brazilian descendants with normal occlusion, and assess whether sexual dimorphism is evident. METHODS: The cephalometric measurements used followed the analyses by Wylie-Johnson, Siriwat-Jarabak, Gebeck, Merrifield and Horn. RESULTS: Results showed dimorphism for total anterior facial height (TAFH), lower anterior facial height (LAFH), anterior facial height (AFH), total posterior facial height (TPFH) and upper posterior facial height (UPFH) measurements. CONCLUSIONS: The standards of facial heights in young Japanese-Brazilian descendants with normal occlusion were observed. Sexual dimorphism was identified in five out of thirteen evaluated variables at this age range. PMID:25715717

  11. Descending thoracic aorta dissection associated with esophageal carcinoma

    Directory of Open Access Journals (Sweden)

    Kaushik Saha

    2013-01-01

    Full Text Available The association of aortic dissection with a malignancy is a rare finding and previous reports are usually those of primary aortic sarcomas. A 45-year-old male presented to us with chest pain and dysphagia for 1 month with a background history of obstructive airway disease and uncontrolled hypertension. In this report we present a case of typical descending aorta dissection with associated esophageal carcinoma.

  12. Giant left anterior descending artery aneurysm resulting in sudden death

    Directory of Open Access Journals (Sweden)

    Chan-Hee Lee

    2016-07-01

    Full Text Available Coronary artery aneurysm is a rare congenital or vascular inflammation-based anomaly for which the clinical course and optimal timing of treatment remain unclear. Here, we report a case of sudden death caused by a giant coronary artery aneurysm of the left anterior descending artery that presented with chest pain. This case suggests that urgent interventional or surgical repair is needed when a large coronary aneurysm presents with acute ischemic symptoms.

  13. Descending necrotizing mediastinitis as a complication of odontogenic infection

    OpenAIRE

    Diamantis, S.; Giannakopoulos, H.; Chou, J.; Foote, J.

    2011-01-01

    Descending necrotizing mediastinitis (DNM) is a serious, life threatening complication that can occur from a common odontogenic infection. Even with advancements in antibiotics, diagnostic imaging, and surgical management, the mortality rate remains between 20 and 40%. It is imperative that the practitioner taking care of patients with odontogenic infections be sensitized to this potentially fatal complication. We report the successful management of a case of mediastinitis complicating an odo...

  14. Total arch and descending thoracic aortic replacement by left thoracotomy.

    Science.gov (United States)

    Corvera, Joel S; Fehrenbacher, John W

    2012-05-01

    The hybrid treatment of transverse aortic arch pathologies with supraaortic debranching and endovascular repair is associated with significant morbidity and death and lacks long-term follow-up. The traditional two-stage open surgical approach to extensive arch and descending thoracic aneurysms carries a significant interval mortality rate. We report the results of a single-stage technique of total arch and descending thoracic aortic replacement by a left thoracotomy. From January 1995 to February 2011, 426 patients underwent thoracic or thoracoabdominal aneurysm repair, of which a highly selected group of 27 patients underwent total arch replacement with descending thoracic or thoracoabdominal aortic replacement. All procedures were performed with hypothermic circulatory arrest and selective antegrade cerebral perfusion. Two patients required transverse division of the sternum. Two patients had emergency or urgent operations. Five patients had concomitant coronary artery bypass, and 1 had concomitant mitral valve replacement. There were no hospital deaths, no cerebrovascular accidents, and one instance of transient spinal cord ischemia. Three patients had acute renal failure not requiring hemodialysis. Intubation in 5 patients exceeded 48 hours, and 1 patient needed tracheostomy. Two patients required reexploration for postoperative bleeding. Survival at 1, 3, and 5 years was 95%, 78%, and 73%, respectively. Replacement of the total arch and descending thoracic aorta by a left thoracotomy provides excellent short-term and long-term results for the treatment of extensive arch and thoracic aortic pathology, without the need for a second-stage operation. Other cardiac pathologies, such as left-sided coronary disease and mitral valve disease, can be addressed concurrently. Copyright © 2012 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  15. Depressed fertility among descendants of immigrants in Sweden

    Directory of Open Access Journals (Sweden)

    Gunnar Andersson

    2017-04-01

    Full Text Available Background: Previous research shows evidence of an interrelation between family formation and the migration of immigrants in Europe. Less research has been conducted on the fertility and family behavior of the descendants of immigrants. Objective: Our study provides analyses of the childbearing behavior of daughters of immigrants in Sweden. The context is that of a country with near-replacement-level fertility and social policies oriented towards social equality. Methods: The study is based on register data covering 1998-2012, which allows for highly detailed analyses of the childbearing behavior of 20 country origin groups of second-generation women. By means of event history techniques, we analyze the transition to any first, second, and third births. Results: Our analyses show that most groups of descendants of immigrants have lower fertility than those with a full Swedish background. The risk of having a first child is particularly depressed, and the risk of having a second child is also lower for daughters of immigrants than for women with two Swedish-born parents. In contrast, many groups of immigrant-descendant two-child mothers display elevated third-birth risks. Conclusions: Our findings demonstrate the necessity to account for parity-specific differences in fertility when studying the fertility of descendants of migrants. Contribution: Our study is based on data large enough to allow for a disaggregated analysis by birth order and parental country background. It shows that, on average, the fertility of women in the so-called second generation in Sweden is lower than that of women with a full Swedish background.

  16. The Last Descendant of Tycho Brahe Lives in Romania

    Science.gov (United States)

    Stavinschi, M.

    On 24 October 1601 passed away, in the 55th year of his life, the great astronomer Tycho Brahe. Now, four centuries since his death, his last descendant is living in Romania: Lydia Baroness Løvendal-Papae. An encyclopedic culture and training as hers can rarely be found today; she also is an excellent specialist in genealogy and heraldry. She has not only the merit of studying the cosmic symbols in heraldry, but especially that of establishing the genealogical tree of the famous Danish astronomer. She also holds a genealogical record: as the last descendant of the old Danish dynasty, she descends from all European dynasties, including the founders of the Romanian countries. We shall dwell here neither upon the great personality of Tycho Brahe, nor on his role in the modern astronomy. We shall not refer to the Tycho catalogue resulted from the space mission Hipparcos. We shall dwell upon the ancient aristocratic family Brahe. The oldest firm mention goes as far back as in 1364, but there are data enough on the existence of some members of this family in the 13th century. The Brahe family was related to a no less famous family, that of the Barons Løvendal. One of the ancestors of Lydia Baroness Løvendal is the renowned Ulrik Frederik Voldemar, Baron, then Count Lovendal, marshal of France (1700-1755), whose name was assigned to one of the most important boulevards of Paris.

  17. The effect of alpha2-adrenergic drugs on the activity of neurons in the rat nucleus raphe magnus in vitro.

    Science.gov (United States)

    Kanda, T; Ohta, Y; Kida, A; Kemmotsu, O

    1999-02-01

    The nucleus raphe magnus (NRM) is an important descending inhibitory system for pain transmission. We tested whether clonidine, an alpha2-adrenergic agonist, and yohimbine, an alpha2-adrenergic antagonist, modulate the activity of NRM neurons using extracellular recording in a rat brainstem slice preparation. Clonidine 1-20 microM increased firing frequencies (FF) in 22 (37%) and decreased FF in 6 (10%) spontaneously active neurons. Correlation between the concentrations of clonidine and FF changes was unremarkable. Eight spontaneously active neurons (13%) showed increases followed by decreases in FF with increasing doses of clonidine. The remaining 24 neurons (40%) showed no change in FF. Yohimbine 1 microM decreased FF in 38 spontaneously active neurons (58%), whereas the remaining 27 neurons (42%) showed no change in FF. In some neurons, yohimbine antagonized the increase or decrease in FF by application of clonidine. In three silent neurons (25%), clonidine (5 or 10 microM) induced firing activity, which stopped or decreased with the increasing doses of clonidine. In the remaining nine neurons (75%), clonidine did not induce firing activity. We conclude that activation and inhibition of alpha2-adrenergic receptors of NRM neurons augments and suppresses output of the descending inhibitory pain pathway. The nucleus raphe magnus is implicated in descending control of the nociceptive processes. We found that clonidine and yohimbine increased and decreased, respectively, the firing activity of a substantial number of nucleus raphe magnus neurons. Clonidine and may facilitate and yohimbine may reduce the outflow of the descending inhibitory pathway.

  18. The development of descending projections from the brainstem to the spinal cord in the fetal sheep

    Directory of Open Access Journals (Sweden)

    Cooke Ian RC

    2007-06-01

    Full Text Available Abstract Background Although the fetal sheep is a favoured model for studying the ontogeny of physiological control systems, there are no descriptions of the timing of arrival of the projections of supraspinal origin that regulate somatic and visceral function. In the early development of birds and mammals, spontaneous motor activity is generated within spinal circuits, but as development proceeds, a distinct change occurs in spontaneous motor patterns that is dependent on the presence of intact, descending inputs to the spinal cord. In the fetal sheep, this change occurs at approximately 65 days gestation (G65, so we therefore hypothesised that spinally-projecting axons from the neurons responsible for transforming fetal behaviour must arrive at the spinal cord level shortly before G65. Accordingly we aimed to identify the brainstem neurons that send projections to the spinal cord in the mature sheep fetus at G140 (term = G147 with retrograde tracing, and thus to establish whether any projections from the brainstem were absent from the spinal cord at G55, an age prior to the marked change in fetal motor activity has occurred. Results At G140, CTB labelled cells were found within and around nuclei in the reticular formation of the medulla and pons, within the vestibular nucleus, raphe complex, red nucleus, and the nucleus of the solitary tract. This pattern of labelling is similar to that previously reported in other species. The distribution of CTB labelled neurons in the G55 fetus was similar to that of the G140 fetus. Conclusion The brainstem nuclei that contain neurons which project axons to the spinal cord in the fetal sheep are the same as in other mammalian species. All projections present in the mature fetus at G140 have already arrived at the spinal cord by approximately one third of the way through gestation. The demonstration that the neurons responsible for transforming fetal behaviour in early ontogeny have already reached the

  19. The Impact of the Organism on Its Descendants

    Directory of Open Access Journals (Sweden)

    Patrick Bateson

    2012-01-01

    Full Text Available Historically, evolutionary biologists have taken the view that an understanding of development is irrelevant to theories of evolution. However, the integration of several disciplines in recent years suggests that this position is wrong. The capacity of the organism to adapt to challenges from the environment can set up conditions that affect the subsequent evolution of its descendants. Moreover, molecular events arising from epigenetic processes can be transmitted from one generation to the next and influence genetic mutation. This in turn can facilitate evolution in the conditions in which epigenetic change was first initiated.

  20. Descending necrotizing mediastinitis as a complication of odontogenic infection.

    Science.gov (United States)

    Diamantis, S; Giannakopoulos, H; Chou, J; Foote, J

    2011-01-01

    Descending necrotizing mediastinitis (DNM) is a serious, life threatening complication that can occur from a common odontogenic infection. Even with advancements in antibiotics, diagnostic imaging, and surgical management, the mortality rate remains between 20 and 40%. It is imperative that the practitioner taking care of patients with odontogenic infections be sensitized to this potentially fatal complication. We report the successful management of a case of mediastinitis complicating an odontogenic infection in a 39-year-old male. Copyright © 2011 Surgical Associates Ltd. Published by Elsevier Ltd. All rights reserved.

  1. Responsibility of parents for misdemeanors committed by their descendants

    Directory of Open Access Journals (Sweden)

    Ristivojević Branislav R.

    2016-01-01

    Full Text Available The subject of the authors' attention are certain questions concerning the responsibility for the acts of other persons in the misdemeanor law of the Republic of Serbia. Under certain conditions, if a child or a minor (descendants commits a misdemeanor, instead of him or together with him, other persons can be held responsible as well, foremost his parents who had not exercised due supervision. There is a difference between the responsibility of a parent whose children have committed a misdemeanor and are under 14, and that of a parent whose children are between 14 and 18 years old. Therefore, there is a difference in terms of responsibility of the parent depending on if the person who committed the misdemeanor is, from the perspective of the Misdemeanor Law, a child or a minor. The authors critically analyze the articles of the Misdemeanor Law that concern the responsibility of the parent for the misdemeanors committed by their descendants. In the end, they conclude that the Misdemeanor Law undermines one of the essential legal principle that the 'scope of rights has to correspond to the scope of obligations and responsibility'.

  2. Multiple curved descending approaches and the air traffic control problem

    Science.gov (United States)

    Hart, S. G.; Mcpherson, D.; Kreifeldt, J.; Wemple, T. E.

    1977-01-01

    A terminal area air traffic control simulation was designed to study ways of accommodating increased air traffic density. The concepts that were investigated assumed the availability of the microwave landing system and data link and included: (1) multiple curved descending final approaches; (2) parallel runways certified for independent and simultaneous operation under IFR conditions; (3) closer spacing between successive aircraft; and (4) a distributed management system between the air and ground. Three groups each consisting of three pilots and two air traffic controllers flew a combined total of 350 approaches. Piloted simulators were supplied with computer generated traffic situation displays and flight instruments. The controllers were supplied with a terminal area map and digital status information. Pilots and controllers also reported that the distributed management procedure was somewhat more safe and orderly than the centralized management procedure. Flying precision increased as the amount of turn required to intersect the outer mark decreased. Pilots reported that they preferred the alternative of multiple curved descending approaches with wider spacing between aircraft to closer spacing on single, straight in finals while controllers preferred the latter option. Both pilots and controllers felt that parallel runways are an acceptable way to accommodate increased traffic density safely and expeditiously.

  3. Surgical treatment of penetrating atherosclerotic ulcer of the descending aorta

    Directory of Open Access Journals (Sweden)

    Kovačević Pavle

    2013-01-01

    Full Text Available Introduction. The term “penetrating atherosclerotic ulcer” (PAU of the aorta describes the condition in which ulceration of an aortic atherosclerotic lesion penetrates the internal elastic lamina into media. PAU is a high-risk lesion due to its deleterious effects on the integrity of aortic wall, with potentially fatal outcome. Case report. A patient with intensive, sharp chest pain irradiating to the back but with no signs of myocardial ischemia on an electrocardiogram was referred to our hospital. Transthoracic echocardiography showed no pathological changes of the ascending aorta. However, multislice computed tomography (CT showed an aortic ulcer with varying degree of the subadventitial hemorrhage in the region of the thoracic aorta at the level of Th 8-9. Due to imminent rupture of the penetrating aortic ulcer, the patient was promptly prepared for surgery. A 15 cm long subadventitial hematoma was found intraoperatively in the right posterolateral aspect of the descending aorta, 5 cm above the diaphragm and 7 cm below the origin of the left subclavial artery. The affected segment of the aorta was resected, followed by an inlay aortic reconstruction with a Dacron tube graft of 24 mm. Control CT revealed satisfactory reconstruction of the descending aorta. Conclusion. PAU is a rare, but potentially fatal disease. Open surgery in patients with PAU is an effective treatment strategy, although endovascular treatment options are emerging.

  4. The Question of the Difference: a study with the descendants of Japanese immigrants in Brazil

    Directory of Open Access Journals (Sweden)

    Patrícia Helena Britisqui Yabiku

    2008-03-01

    Full Text Available The main objectives of this work are: to understand the perceptions that undergraduate students, descendants of Japanese immigrants, have on themselves; to identify the images that Brazilian undergraduate students whose ascendants are not Japanese have on the Japanese descendants; to compare these images to the expected images the Japanese students have on others’ perceptions about them. In such a way we conducted half-structuralized interviews with the Japanese descendants and applied a Likert type scale of 5 points questionnaire to the non Japanese group. The analyzed data don’t allowed to conclude on the existence of preconceptions in relation to the Japanese descendants , but it shows the Japanese and their descendants are perceived as different by the own Japanese descendants and their friends, which points to the importance of deepening the discussion about the identity formation of the immigrants and their descendants in Brazilian society.

  5. Noisy Neurons

    Indian Academy of Sciences (India)

    IAS Admin

    Nerves are fibres that conduct electrical signals and hence pass on information from and to the brain. Nerves are made of nerve cells called neurons (Figure 1). Instructions in our body are sent via electrical signals that present themselves as variations in the potential across neuronal membranes. These potential differences ...

  6. The Descending Diencephalic Dopamine System Is Tuned to Sensory Stimuli.

    Science.gov (United States)

    Reinig, Sebastian; Driever, Wolfgang; Arrenberg, Aristides B

    2017-02-06

    The vertebrate diencephalic A11 system provides the sole dopaminergic innervation of hindbrain and spinal cord and has been implicated in modulation of locomotion and sensory processes. However, the exact contributions of sensory stimuli and motor behavior to A11 dopaminergic activity remain unclear. We recorded cellular calcium activity in four anatomically distinct posterior tubercular A11-type dopaminergic subgroups and two adjacent hypothalamic dopaminergic groups in GCaMP7a-transgenic, semi-restrained zebrafish larvae. Our analyses reveal the contributions of different sensory modalities and motor states to dopaminergic activity. Each posterior tubercular and hypothalamic subgroup showed distinct activity patterns, while activity was synchronous within individual subgroups. Caudal and dorsomedial hypothalamic dopaminergic neurons are activated following vigorous tail movements and stay active for about 10 s, revealing predominantly post-motor activity. In contrast, posterior tubercular dopaminergic neurons are predominantly sensory driven, with subgroups differentially responding to different tactile or visual sensory modalities. In the anterior subgroups, neuronal response magnitudes are tuned to tactile stimulus intensities, revealing features similar to sensory systems. We identify the lateral line system as source for this tactile tuning. In contrast, the posterior subgroup is responsive to distinct moving visual stimuli. Specifically, translational forward stimuli, which may indicate insufficient rheotaxis and drift, induce dopaminergic activity, but backward or rotational stimuli not. The activation of posterior tubercular dopaminergic neurons by sensory stimuli, and their projections onto peripheral mechanosensory systems, suggests a participation of A11-type neurons in the feedback regulation of sensory systems. Together with the adjacent hypothalamic neurons, they may serve to set basic behavioral states. Copyright © 2017 Elsevier Ltd. All rights

  7. Descending necrotizing mediastinitis after a trigger point injection.

    Science.gov (United States)

    Choe, Jae Young; Kim, Jong Kun; Lee, Dong Eun; Seo, Kang Suk; Park, Jung Bae; Lee, Mi Jin; Ryoo, Hyun Wook; Ahn, Jae Yun; Moon, Sungbae

    2017-09-01

    Descending necrotizing mediastinitis (DNM) is a rare form of mediastinal infection. Most cases are associated with esophageal rupture. DNM after a trigger point injection in the upper trapezius has not been described previously. We present a case of DNM after a trigger point injection in the upper trapezius. A 70-year-old man visited the emergency department with chest discomfort and fever after a trigger point injection in the left upper trapezius. Chest computed tomography showed evidence of DNM, and antibiotic therapy was immediately administered intravenously. Because of the risk of sudden death, poor prognosis due to underlying disease, and his age, he declined surgical treatment and died of septic shock. Although trigger point injections are generally considered safe, caution should be used in patients with an underlying disease or in the elderly. Early diagnosis, broad-spectrum antibiotics, and aggressive surgical management are essential to improve the prognosis.

  8. An extinct vertebrate preserved by its living hybridogenetic descendant.

    Science.gov (United States)

    Dubey, Sylvain; Dufresnes, Christophe

    2017-10-06

    Hybridogenesis is a special mode of hybrid reproduction where one parental genome is eliminated and the other is transmitted clonally. We propose that this mechanism can perpetuate the genome of extinct species, based on new genetic data from Pelophylax water frogs. We characterized the genetic makeup of Italian hybridogenetic hybrids (P. kl. hispanicus and esculentus) and identified a new endemic lineage of Eastern-Mediterranean origin as one parental ancestor of P. kl. hispanicus. This taxon is nowadays extinct in the wild but its germline subsists through its hybridogenetic descendant, which can thus be considered as a "semi living fossil". Such rare situation calls for realistic efforts of de-extinction through selective breeding without genetic engineering, and fuels the topical controversy of reviving long extinct species. "Ghost" species hidden by taxa of hybrid origin may be more frequent than suspected in vertebrate groups that experienced a strong history of hybridization and semi-sexual reproduction.

  9. Testicular Descend, How and Why: A Review Article

    Directory of Open Access Journals (Sweden)

    Sujan Narayan Agrawal

    2017-08-01

    Full Text Available Background: The testis develops in the dorsal abdominal wall, and then descends to scrotum. The development begins as early as 6th week of intrauterine life and is completed by fifth month of intrauterine life. The testis may get arrested during its descent from dorsal abdominal wall to scrotum. The anomalies of descent includes cryptorchism (and its variant like anarchism, monarchism or partially descended testis, ectopic testis, persistent processus vaginalis and encysted hydrocoel of spermatic cord etc. Cryptorchism is usually diagnosed during the new born examination. The recognition of this condition, identification of associated syndromes, proper diagnostic evaluation and timely treatment by surgical urologist is important to prevent adverse consequences like sterility, congenital hernia & hydrocoel, testicular carcinoma etc. Objectives: the objective of this review is to study the role of gubernaculum in the testicular migration process. Material & Method: We performed a descriptive review of the literature about the role of the gubernaculum in testicular migration during the human fetal life. This article provides an overview of role of gubernaculum and other factors responsible for gonadal migration. Results: In the first phase of testicular migration the gubernaculum enlarges to hold the testis near groin and in the second phase the gubernaculum migrates across the pubic region to reach the scrotum. The proximal end of gubernaculum is attached to the testis and epididymis. The lower end reaches to bottom of scrotum. A failure in the proper functioning of gubernaculum causes cryptorchism. Rarely male gonads may deviate from main pathway due to presence of many tails of distal gubernaculum, and it may give rise to ectopic testis. The processus vaginalis usually closes by birth. If it remains patent, it leads to congenital hernia, hydrocoel, encysted hydrocoel etc. Conclusion: the gubernaculum presents a significant structure during

  10. [Foods native to indigenous and afro-descendents in Colombia].

    Science.gov (United States)

    Rivas Abadía, Ximena; Carolina Pazos, Sonia; Castillo Castillo, Silvana Katerin; Pachón, Helena

    2010-09-01

    For social programs in Colombia, like those administered by the Instituto Colombiano de Bienestar Familiar (ICBF), it's important to know what native foods minority groups consume. This research obtained information on native foods consumed by indigenous and afro-descendents living in 10 Colombian departments: Cauca, Nariño, Amazonas, Chocó, Guainia, Vichada, Magdalena, Guajira, Cesar y Vaupés. A questionnaire was applied to key informants (individually or in groups), addressing the following topics: personal information on the informant, name and type of food, if consumed by indigenous and/or afro-Colombians, climate where produced, time of year when harvested, if consumed raw or cooked, preparations, properties ascribed to the food, and current production, use and availability. Key informants included participants in ICBF's programs, indigenous authorities, teachers, traditional healers, and others, under the supervision of professionals from ICBF's mobile unit in each department. Bibliography (n = 123 documents) was compiled and reviewed. In the departments selected, 13 municipalities were visited, 139 individuals were interviewed and at least 92 new foods (i.e., not currently included in the Colombian Food Composition Table) were identified. Among the 92, the scientific name was obtained for 62 foods. Of these, 2 were classified as other, 18 as meats, 3 as insects, and 39 as plants. Among the plants, informants mentioned fruit (n=29), leaves (n=4), seed (n=3) and roots (n=3). Indigenous and afro-descendent communities in Colombia report consuming dozens of foods that are not currently in the Colombian Food Composition Table.

  11. Inheriting discontinued bonds: trauma-descendant relations with the genocide dead.

    Science.gov (United States)

    Kidron, Carol A

    2014-01-01

    Despite the scholarship on continuing bonds with the dead and the critique of pathologizing paradigms in trauma theory, little is known of the engagement between trauma descendants and relatives who perished prior to their birth. A sample of 55 Holocaust descendants was recruited in Israel to participate in semistructured ethnographic interviews. Descendants reported on the normalized presence of and engagement with the dead and the restoration of previously "discontinued" bonds. Findings were consistent with the scholarship on the therapeutic role of continuing bonds and with meta-analyses normalizing descendant psychosocial legacies. Jewish-Israeli paradigms of memory facilitated therapeutic bonds with the dead.

  12. Hindbrain V2a neurons in the excitation of spinal locomotor circuits during zebrafish swimming.

    Science.gov (United States)

    Kimura, Yukiko; Satou, Chie; Fujioka, Shunji; Shoji, Wataru; Umeda, Keiko; Ishizuka, Toru; Yawo, Hiromu; Higashijima, Shin-ichi

    2013-05-20

    During locomotion in vertebrates, reticulospinal neurons in the hindbrain play critical roles in providing descending excitation to the spinal cord locomotor systems. However, despite the fact that many genes that are used to classify the neuronal identities of neurons in the hindbrain have been identified, the molecular identity of the reticulospinal neurons that are critically involved in locomotor drive is not well understood. Chx10-expressing neurons (V2a neurons) are ipsilaterally projecting glutamatergic neurons in the spinal cord and the hindbrain. Many of the V2a neurons in the hindbrain are known to project to the spinal cord in zebrafish, making hindbrain V2a neurons a prime candidate in descending locomotor drive. We investigated the roles of hindbrain V2a neurons using optogenetic and electrophysiological approaches. The forced activation of hindbrain V2a neurons using channelrhodopsin efficiently evoked swimming, whereas the forced inactivation of them using Archearhodopsin3 or Halorhodpsin reliably stopped ongoing swimming. Electrophysiological recordings of two populations of hindbrain reticulospinal V2a neurons showed that they were active during swimming. One population of neurons, small V2a neurons in the caudal hindbrain, fired with low rhythmicity, whereas the other population of neurons, large reticulospinal V2a neurons, called MiV1 neurons, fired more rhythmically. These results indicated that hindbrain reticulospinal V2a neurons play critical roles in providing excitation to the spinal locomotor circuits during swimming by providing both tonic and phasic inputs to the circuits. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Ten years of descending necrotizing mediastinitis: management of 23 cases.

    Science.gov (United States)

    Roccia, Fabio; Pecorari, Gian Carlo; Oliaro, Alberto; Passet, Ettore; Rossi, Paolo; Nadalin, Juri; Garzino-Demo, Paolo; Berrone, Sid

    2007-09-01

    Through a 10-year retrospective study, we report our experience in the management of descending necrotizing mediastinitis (DNM), a rare and often lethal complication of odontogenic and oropharyngeal infections. We reassessed 23 patients between the ages of 16 and 69 years (mean, 49 years) seen between 1996 and 2005, with DNM secondary to odontogenic abscess or phlegmon in 9 cases or secondary to peritonsillar abscess in 14 cases. In this study, 48% of the patients had immune system disorders, mainly diabetes mellitus (6 patients). The diagnosis of DNM was confirmed by cervicothoracic computed tomography. Eight patients underwent a bilateral collar cervicotomy, and 15 underwent a combined cervicothoracic approach. Five, 2, 1, and 1 patients underwent surgery 2, 3, 4, and 5 times, respectively. Seven patients died as a result of septic shock and multiorgan failure, for a mortality rate of 30.4%. Four of those who died had a compromised immune system. The relatively high mortality rate seen in this study shows that, in addition to early diagnosis and aggressive treatment, it is important to give greater attention to and be more medically and surgically aggressive in the management of patients whose immune system is compromised in any way.

  14. Partnership dynamics among migrants and their descendants in Estonia

    Directory of Open Access Journals (Sweden)

    Leen Rahnu

    2015-06-01

    Full Text Available Background: Extensive scholarly literature documents the decline in marriage and increase in non-marital cohabitation and divorce across regions and countries of Europe, but we know less about the extent to which these new family behaviours that have emerged in host societies are adopted by migrants. Objective: The aim of this study is to examine partnership transitions among the migrants and their descendants in Estonia, who mainly originate from the European part of Russia. By investigating an East European context, the study contributes to a more comprehensive account of migrant populations in different socio-economic and cultural settings. Methods: The study is based on the Estonian Generations and Gender Survey (2004/2005 and the Estonian Family and Fertility Survey (1994/1997, and employs proportional hazards models. Results: The results show that new family formation patterns, associated with the Second Demographic Transition, are less prevalent among migrants. The difference between migrants and native Estonians is most pronounced in the mode of partnership formation and outcomes of cohabiting unions, whereas the results pertaining to union dissolution reveal a less systematic difference between population groups. Reflecting the relatively slow integration, the second-generation migrants exhibit partnership behaviour that differs from that of the native population. The observed differences between migrants and the native population appear largely similar for both men and women. Conclusions: The results lend support to socialisation, cultural maintenance, and adaptation hypotheses, and underscore the importance of contextual factors. The analysis reveals disruption effects of migration on partnership processes.

  15. [Mirror neurons].

    Science.gov (United States)

    Rubia Vila, Francisco José

    2011-01-01

    Mirror neurons were recently discovered in frontal brain areas of the monkey. They are activated when the animal makes a specific movement, but also when the animal observes the same movement in another animal. Some of them also respond to the emotional expression of other animals of the same species. These mirror neurons have also been found in humans. They respond to or "reflect" actions of other individuals in the brain and are thought to represent the basis for imitation and empathy and hence the neurobiological substrate for "theory of mind", the potential origin of language and the so-called moral instinct.

  16. Hybrid Approach of Aortic Diseases: Zone 1 Delivery and Volumetric Analysis on the Descending Aorta.

    Science.gov (United States)

    Duncan, José Augusto; Dias, Ricardo Ribeiro; Dinato, Fabrício José; Fernandes, Fábio; Ramirez, Félix José Álvares; Mady, Charles; Jatene, Fabio Biscegli

    2017-01-01

    Conventional techniques of surgical correction of arch and descending aortic diseases remains as high-risk procedures. Endovascular treatments of abdominal and descending thoracic aorta have lower surgical risk. Evolution of both techniques - open debranching of the arch and endovascular approach of the descending aorta - may extend a less invasive endovascular treatment for a more extensive disease with necessity of proximal landing zone in the arch. To evaluate descending thoracic aortic remodeling by means of volumetric analysis after hybrid approach of aortic arch debranching and stenting the descending aorta. Retrospective review of seven consecutive patients treated between September 2014 and August 2016 for diseases of proximal descending aorta (aneurysms and dissections) by hybrid approach to deliver the endograft at zone 1. Computed tomography angiography were analyzed using a specific software to calculate descending thoracic aorta volumes pre- and postoperatively. Follow-up was done in 100% of patients with a median time of 321 days (range, 41-625 days). No deaths or permanent neurological complications were observed. There were no endoleaks or stent migrations. Freedom from reintervention was 100% at 300 days and 66% at 600 days. Median volume reduction was of 45.5 cm3, representing a median volume shrinkage by 9.3%. Hybrid approach of arch and descending thoracic aorta diseases is feasible and leads to a favorable aortic remodeling with significant volume reduction.

  17. Hybrid Approach of Aortic Diseases: Zone 1 Delivery and Volumetric Analysis on the Descending Aorta

    Directory of Open Access Journals (Sweden)

    José Augusto Duncan

    Full Text Available Abstract Introduction: Conventional techniques of surgical correction of arch and descending aortic diseases remains as high-risk procedures. Endovascular treatments of abdominal and descending thoracic aorta have lower surgical risk. Evolution of both techniques - open debranching of the arch and endovascular approach of the descending aorta - may extend a less invasive endovascular treatment for a more extensive disease with necessity of proximal landing zone in the arch. Objective: To evaluate descending thoracic aortic remodeling by means of volumetric analysis after hybrid approach of aortic arch debranching and stenting the descending aorta. Methods: Retrospective review of seven consecutive patients treated between September 2014 and August 2016 for diseases of proximal descending aorta (aneurysms and dissections by hybrid approach to deliver the endograft at zone 1. Computed tomography angiography were analyzed using a specific software to calculate descending thoracic aorta volumes pre- and postoperatively. Results: Follow-up was done in 100% of patients with a median time of 321 days (range, 41-625 days. No deaths or permanent neurological complications were observed. There were no endoleaks or stent migrations. Freedom from reintervention was 100% at 300 days and 66% at 600 days. Median volume reduction was of 45.5 cm3, representing a median volume shrinkage by 9.3%. Conclusion: Hybrid approach of arch and descending thoracic aorta diseases is feasible and leads to a favorable aortic remodeling with significant volume reduction.

  18. Diffuse descending necrotising mediastinitis and pleural empyema secondary to acute odontogenic infection resulting in severe dysphagia.

    Science.gov (United States)

    Glen, Peter; Morrison, James

    2016-03-24

    We report a case of acute odontogenic sepsis in a 59-year-old man, presenting with diffuse, descending necrotising mediastinitis complicated by pleural empyema. Despite surviving the odds, his recovery was complicated by severe dysphagia, resulting in gastrostomy feeding for 6 months. Until now, severe dysphagia following descending necrotising mediastinitis has been unreported. 2016 BMJ Publishing Group Ltd.

  19. Intima-media thickness of the descending aorta in patients with bicuspid aortic valve

    Directory of Open Access Journals (Sweden)

    Johan Petrini

    2016-06-01

    Conclusions: Intima-media thickness of the descending aorta is not affected by aortic valve morphology (BAV/TAV; age is the main determinant of AoIMT. Genetic markers (SNPs known to influence IMT in the carotid artery seem to correlate to IMT in the descending aorta only in patients with TAV.

  20. Noisy Neurons

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 1. Noisy Neurons: Hodgkin-Huxley Model and Stochastic Variants. Shurti Paranjape. General Article Volume 20 Issue 1 January 2015 pp 34-43. Fulltext. Click here to view fulltext PDF. Permanent link:

  1. Descending and tonotopic projection patterns from the auditory cortex to the inferior colliculus.

    Science.gov (United States)

    Straka, M M; Hughes, R; Lee, P; Lim, H H

    2015-08-06

    The inferior colliculus (IC) receives many corticofugal projections, which can mediate plastic changes such as shifts in frequency tuning or excitability of IC neurons. While the densest projections are found in the IC's external cortices, fibers originating from the primary auditory cortex (AI) have been observed throughout the IC's central nucleus (ICC), and these projections have shown to be organized tonotopically. Some studies have also found projections from other core and non-core cortical regions, though the organization and function of these projections are less known. In guinea pig, there exists a non-core ventrorostral belt (VRB) region that has primary-like properties and has often been mistaken for AI, with the clearest differentiating characteristic being VRB's longer response latencies. To better understand the auditory corticofugal descending system beyond AI, we investigated if there are projections from VRB to the ICC and if they exhibit a different projection pattern than those from AI. In this study, we performed experiments in ketamine-anesthetized guinea pigs, in which we positioned 32-site electrode arrays within AI, VRB, and ICC. We identified the monosynaptic connections between AI-to-ICC and VRB-to-ICC using an antidromic stimulation method, and we analyzed their locations across the midbrain using three-dimensional histological techniques. Compared to the corticocollicular projections to the ICC from AI, there were fewer projections to the ICC from VRB, and these projections had a weaker tonotopic organization. The majority of VRB projections were observed in the caudal-medial versus the rostral-lateral region along an isofrequency lamina of the ICC, which is in contrast to the AI projections that were scattered throughout an ICC lamina. These findings suggest that the VRB directly modulates sound information within the ascending lemniscal pathway with a different or complementary role compared to the modulatory effects of AI, which may

  2. Argillization by descending acid at Steamboat Springs, Nevada

    Science.gov (United States)

    Schoen, Robert; White, Donald E.; Hemley, J.J.

    1974-01-01

    Steamboat Springs, Nevada, an area of present-day hot springs, clearly illustrates the genetic dependence of some kaolin deposits on hot-spring activity. Andesite, granodiorite and arkosic sediments are locally altered at the land surface to siliceous residues consisting of primary quartz and anatase, plus opal from primary silicates. These siliceous residues commonly exhibit the textural and structural features of their unaltered equivalents. Beneath the siliceous residues, kaolin and alunite replace primary silicates and fill open spaces, forming a blanketlike deposit. Beneath the kaolin-alunite zone, montmorillonite, commonly accompanied by pyrite, replaces the primary silicates. On the ground surface, the same alteration mineral zones can be traced outward from the siliceous residue; however, hematite rather than pyrite accompanies montmorillonite.Chemical analysis indicates that sulfuric acid is the active altering agent. The acid forms from hydrogen sulfide that exsolves from deep thermal water, rises above the water table and is oxidized by sulfur-oxidizing bacteria living near the ground surface. This acid dissolves in precipitation or condensed water vapor and percolates downward destroying most of the primary minerals producing a siliceous residue. Coincidence of the water table with the downward transition from siliceous residue to kaolin-alunite signifies decreasing hydrogen metasomatism because of dilution of descending acid by ground water.In hot-spring areas, beds of siliceous sinter deposited at the surface by hypogene thermal water look, superficially, like areas of surficial acid alteration. Features diagnostic of a surficial alteration are the relict rock structures of a siliceous residue and a kaolin-alunite zone immediately beneath.

  3. Control of abdominal and expiratory intercostal muscle activity during vomiting - Role of ventral respiratory group expiratory neurons

    Science.gov (United States)

    Miller, Alan D.; Tan, L. K.; Suzuki, Ichiro

    1987-01-01

    The role of ventral respiratory group (VRG) expiratory (E) neurons in the control of abdominal and internal intercostal muscle activity during vomiting was investigated in cats. Two series of experiments were performed: in one, the activity of VRG E neurons was recorded during fictive vomiting in cats that were decerebrated, paralyzed, and artificially ventilated; in the second, the abdominal muscle activity during vomiting was compared before and after sectioning the axons of descending VRG E neurons in decerebrate spontaneously breathing cats. The results show that about two-thirds of VRG E neurons that project at least as far caudally as the lower thoracic cord contribute to internal intercostal muscle activity during vomiting. The remaining VRG E neurons contribute to abdominal muscle activation. As shown by severing the axons of the VRG E neurons, other, as yet unidenified, inputs (either descending from the brain stem or arising from spinal reflexes) can also produce abdominal muscle activation.

  4. Local-circuit phenotypes of layer 5 neurons in motor-frontal cortex of YFP-H mice

    Directory of Open Access Journals (Sweden)

    Jianing Yu

    2008-12-01

    Full Text Available Layer 5 pyramidal neurons comprise an important but heterogeneous group of cortical projection neurons. In motor-frontal cortex, these neurons are centrally involved in the cortical control of movement. Recent studies indicate that local excitatory networks in mouse motor-frontal cortex are dominated by descending pathways from layer 2/3 to 5. However, those pathways were identified in experiments involving unlabeled neurons in wild type mice. Here, to explore the possibility of class-specific connectivity in this descending pathway, we mapped the local sources of excitatory synaptic input to a genetically labeled population of cortical neurons: YFP-positive layer 5 neurons of YFP-H mice. We found, first, that in motor cortex, YFP-positive neurons were distributed in a double blade, consistent with the idea of layer 5B having greater thickness in frontal neocortex. Second, whereas unlabeled neurons in upper layer 5 received their strongest inputs from layer 2, YFP-positive neurons in the upper blade received prominent layer 3 inputs. Third, YFP-positive neurons exhibited distinct electrophysiological properties, including low spike frequency adaptation, as reported previously. Our results with this genetically labeled neuronal population indicate the presence of distinct local-circuit phenotypes among layer 5 pyramidal neurons in mouse motor-frontal cortex, and present a paradigm for investigating local circuit organization in other genetically labeled populations of cortical neurons.

  5. Motor Neurons

    DEFF Research Database (Denmark)

    Hounsgaard, Jorn

    2017-01-01

    Motor neurons translate synaptic input from widely distributed premotor networks into patterns of action potentials that orchestrate motor unit force and motor behavior. Intercalated between the CNS and muscles, motor neurons add to and adjust the final motor command. The identity and functional...... properties of this facility in the path from synaptic sites to the motor axon is reviewed with emphasis on voltage sensitive ion channels and regulatory metabotropic transmitter pathways. The catalog of the intrinsic response properties, their underlying mechanisms, and regulation obtained from motoneurons...... in in vitro preparations is far from complete. Nevertheless, a foundation has been provided for pursuing functional significance of intrinsic response properties in motoneurons in vivo during motor behavior at levels from molecules to systems....

  6. Characteristics and Outcomes of Ascending Versus Descending Thoracic Aortic Aneurysms.

    Science.gov (United States)

    Vapnik, Joshua S; Kim, Joon Bum; Isselbacher, Eric M; Ghoshhajra, Brian B; Cheng, Yisha; Sundt, Thoralf M; MacGillivray, Thomas E; Cambria, Richard P; Lindsay, Mark E

    2016-05-15

    Thoracic aortic aneurysms (TAs) occur in reproducible patterns, but etiologic factors determining the anatomic distribution of these aneurysms are not well understood. This study sought to gain insight into etiologic differences and clinical outcomes associated with repetitive anatomic distributions of TAs. From 3,247 patients registered in an institutional Thoracic Aortic Center database from July 1992 to August 2013, we identified 844 patients with full aortic dimensional imaging by computerized axial tomography or magnetic resonance imaging scan (mean age 62.8 ± 14 years, 37% women, median follow-up 40 months) with TA diameter >4.0 cm and without evidence of previous aortic dissection. Patient demographic and imaging data were analyzed in 3 groups: isolated ascending thoracic aortic aneurysms (AAs; n = 628), isolated descending TAs (DTAs; n = 130), and combined AA and DTA (mixed thoracic aortic aneurysm, MTA; n = 86). Patients with DTA had more hypertension (82% vs 59%, p <0.001) and a higher burden of atherosclerosis (88% vs 9%, p <0.001) than AA. Conversely, patients with isolated AA were younger (59.5 ± 13.5 vs 71.0 ± 11.8 years, p <0.001) and contained almost every case of overt, genetically triggered TA. Patients with isolated DTA were demographically indistinguishable from patients with MTA. In follow-up, patients with DTA/MTA experienced more aortic events (aortic dissection/rupture) and had higher mortality than patients with isolated AA. In multivariate analysis, aneurysm size (odds ratio 1.1, 95% CI 1.07 to 1.16, p <0.001) and the presence of atherosclerosis (odds ratio 5.7, 95% CI 2.02 to 16.15, p <0.001) independently predicted adverse aortic events. We find that DTA with or without associated AA appears to be a disease more highly associated with atherosclerosis, hypertension, and advanced age. In contrast, isolated AA appears to be a clinically distinct entity with a greater burden of genetically triggered disease. Copyright © 2016

  7. D2-like receptors in the descending dopaminergic pathway are not involved in the decreased postoperative nociceptive threshold induced by plantar incision in adult rats

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    Ohtani N

    2016-10-01

    Full Text Available Norimasa Ohtani, Eiji Masaki Division of Dento-oral Anesthesiology, Tohoku University Graduate School of Dentistry, Sendai, Miyagi, Japan Background: Approximately half of all patients who undergo surgery develop postoperative pain, the mechanisms of which are not well understood by anesthesiologists. D2-like receptors in the descending dopaminergic pathway play an important role in regulation of pain transmission in the spinal cord. Impairment of inhibitory neurons in the spinal cord is suggested as part of the mechanism for neuropathic pain, which is one component of postoperative pain. The purpose of this study was to investigate whether impairment of D2-like receptors in the descending dopaminergic pathway in the spinal cord is involved in the decreased postoperative nociceptive threshold in rats.Methods: Male Sprague-Dawley rats (250–300 g were anesthetized with sevoflurane and an intrathecal (IT catheter was implanted. Six days later, a plantar incision was made. On the following day, saline, a D2-like receptor agonist (quinpirole, or a D2-like receptor antagonist (sulpiride was administered intrathecally. Thermal and mechanical nociceptive responses were assessed by exposure to infrared radiant heat and the von Frey filament test before and after plantar incision.Results: Plantar incision decreased both thermal latency and the mechanical nociceptive threshold. IT administration of quinpirole inhibited the nociceptive responses induced by plantar incision, but sulpiride had no effect.Conclusion: A D2-like receptor agonist had antinociceptive effects on the hypersensitivity response triggered by a surgical incision, but a D2-like receptor antagonist had no effect on this response. These results suggest that impairment and/or modification of D2-like receptors in the descending dopaminergic pathway in the spinal cord is not involved in the postoperative decrease in nociceptive threshold. Keywords: postoperative pain, descending pathway

  8. Neurons other than motor neurons in motor neuron disease.

    Science.gov (United States)

    Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

    2017-11-01

    Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

  9. Is there equity in use of healthcare services among immigrants, their descendents, and ethnic Danes?

    DEFF Research Database (Denmark)

    Nielsen, Signe S; Hempler, Nana F; Waldorff, Frans B

    2012-01-01

    Legislation in Denmark explicitly states the right to equal access to healthcare. Nevertheless, inequities may exist; accordingly evidence is needed. Our objective was to investigate whether differences in healthcare utilisation in immigrants, their descendents, and ethnic Danes could be explained...

  10. A Case of Advanced Descending Colon Cancer in an Adult Patient with Intestinal Malrotation

    Directory of Open Access Journals (Sweden)

    Yoshifumi Nakayama

    2016-01-01

    Full Text Available This report presents an operative case of advanced descending colon cancer in an adult patient with intestinal malrotation. A 63-year-old Japanese male was suffering from left side abdominal pain, abdominal distension, and constipation. An endoscopic examination revealed an advanced tumor in the descending colon. Computed tomography (CT of the abdomen revealed the thickening of the descending colon wall and superior mesenteric vein rotation. An opaque enema detected severe stenosis of the descending colon. An abdominal X-ray examination revealed the dilation of the colon and small intestine with niveau. At the insertion of an ileus tube, the C-loop of the duodenum was observed to be absent and the small intestine was located on the right side of the abdomen. After the decompression of the bowel contents, laparotomy was performed. Descending colon cancer was observed to have directly invaded the left side of the transverse colon. Left hemicolectomy, lymph node dissection, and appendectomy were performed. The patient had an uneventful recovery and was discharged from the hospital on the 16th day after surgery. This report presents a rare operative case of descending colon cancer in an adult patient with intestinal malrotation.

  11. Noninvasive Reactivation of Motor Descending Control after Paralysis.

    Science.gov (United States)

    Gerasimenko, Yury P; Lu, Daniel C; Modaber, Morteza; Zdunowski, Sharon; Gad, Parag; Sayenko, Dimitry G; Morikawa, Erika; Haakana, Piia; Ferguson, Adam R; Roy, Roland R; Edgerton, V Reggie

    2015-12-15

    The present prognosis for the recovery of voluntary control of movement in patients diagnosed as motor complete is generally poor. Herein we introduce a novel and noninvasive stimulation strategy of painless transcutaneous electrical enabling motor control and a pharmacological enabling motor control strategy to neuromodulate the physiological state of the spinal cord. This neuromodulation enabled the spinal locomotor networks of individuals with motor complete paralysis for 2-6 years American Spinal Cord Injury Association Impairment Scale (AIS) to be re-engaged and trained. We showed that locomotor-like stepping could be induced without voluntary effort within a single test session using electrical stimulation and training. We also observed significant facilitation of voluntary influence on the stepping movements in the presence of stimulation over a 4-week period in each subject. Using these strategies we transformed brain-spinal neuronal networks from a dormant to a functional state sufficiently to enable recovery of voluntary movement in five out of five subjects. Pharmacological intervention combined with stimulation and training resulted in further improvement in voluntary motor control of stepping-like movements in all subjects. We also observed on-command selective activation of the gastrocnemius and soleus muscles when attempting to plantarflex. At the end of 18 weeks of weekly interventions the mean changes in the amplitude of voluntarily controlled movement without stimulation was as high as occurred when combined with electrical stimulation. Additionally, spinally evoked motor potentials were readily modulated in the presence of voluntary effort, providing electrophysiological evidence of the re-establishment of functional connectivity among neural networks between the brain and the spinal cord.

  12. Medullary raphe nuclei activate the lumbosacral defecation center through the descending serotonergic pathway to regulate colorectal motility in rats.

    Science.gov (United States)

    Nakamori, Hiroyuki; Naitou, Kiyotada; Horii, Yuuki; Shimaoka, Hiroki; Horii, Kazuhiro; Sakai, Hiroki; Yamada, Akihiro; Furue, Hidemasa; Shiina, Takahiko; Shimizu, Yasutake

    2018-03-01

    Colorectal motility is regulated by two defecation centers located in the brain and spinal cord. In previous studies, we have shown that administration of serotonin (5-HT) in the lumbosacral spinal cord causes enhancement of colorectal motility. Because spinal 5-HT is derived from neurons of the medullary raphe nuclei, including the raphe magnus, raphe obscurus, and raphe pallidus, we examined whether stimulation of the medullary raphe nuclei enhances colorectal motility via the lumbosacral defecation center. Colorectal pressure was recorded with a balloon in vivo in anesthetized rats. Electrical stimulation of the medullary raphe nuclei failed to enhance colorectal motility. Because GABAergic neurons can be simultaneously activated by the raphe stimulation and released GABA masks accelerating actions of the raphe nuclei on the lumbosacral defecation center, a GABA A receptor antagonist was preinjected intrathecally to manifest excitatory responses. When spinal GABA A receptors were blocked by the antagonist, electrical stimulation of the medullary raphe nuclei increased colorectal contractions. This effect of the raphe nuclei was inhibited by intrathecal injection of 5-hydroxytryptamine type 2 (5-HT 2 ) and type 3 (5-HT 3 ) receptor antagonists. In addition, injection of a selective 5-HT reuptake inhibitor in the lumbosacral spinal cord augmented the raphe stimulation-induced enhancement of colorectal motility. Transection of the pelvic nerves, but not transection of the colonic nerves, prevented the effect of the raphe nuclei on colorectal motility. These results demonstrate that activation of the medullary raphe nuclei causes augmented contractions of the colorectum via 5-HT 2 and 5-HT 3 receptors in the lumbosacral defecation center. NEW & NOTEWORTHY We have shown that electrical stimulation of the medullary raphe nuclei causes augmented contractions of the colorectum via pelvic nerves in rats. The effect of the medullary raphe nuclei on colorectal motility is

  13. Effects of ascending and descending climbers on space elevator cable dynamics

    Science.gov (United States)

    Ishikawa, Yoji; Otsuka, Kiyotoshi; Yamagiwa, Yoshiki; Doi, Hinata

    2018-04-01

    Based on a mass-point model, the cable dynamics of a space elevator during a climber's travel motion are examined. The cable response during a single operation of one ascending or descending climber is analyzed first, and then, based on the results, the cable dynamics for simultaneous operation of an ascending and a descending climber are evaluated. For the single operation, bending is significant when the climber is traveling near the Earth's surface. The cable also inclines with periodic oscillation as a result of a Coriolis force corresponding to the climber velocity. However, simultaneous operation of ascending and descending climbers can suppress the inclination of the cable by almost a factor of ten. In simultaneous operation, compared to single operation, a descending climber has a smaller amplitude of libration angle and less cable bending, while an ascending climber has a smaller amplitude when the climber is traveling at a higher altitude with climber velocities of 200 km/h and 400 km/h. The phase of the oscillation of the overall cable is found to be close to that of the descending climber. Cable bending is suppressed for any examined climber velocity, but the dependency of this suppression of displacement on climber velocity is not found. In summary, simultaneous operation can surely suppress the inclination of the cable via the cancellation of Coriolis forces by the two climbers.

  14. Neurochemical properties of BDNF-containing neurons projecting to rostral ventromedial medulla in the ventrolateral periaqueductal gray

    Directory of Open Access Journals (Sweden)

    Jun-Bin eYin

    2014-11-01

    Full Text Available The periaqueductal gray (PAG modulates nociception via a descending pathway that relays in the rostral ventromedial medulla (RVM and terminates in the spinal cord. Previous behavioral pharmacology and electrophysiological evidence suggests that brain-derived neurotrophic factor (BDNF plays an important role in descending pain modulation, likely through the PAG-RVM pathway. However, there still lacks detailed information on the distribution of BDNF, activation of BDNF-containing neurons projecting to RVM in the condition of pain, and neurochemical properties of these neurons within the PAG. Through fluorescent in situ hybridization (FISH and immunofluorescent staining, the homogenous distributions of BDNF mRNA and protein were observed in the four subregions of PAG. Both neurons and astrocytes expressed BDNF, but not microglias. By combining retrograde tracing methods and formalin pain model, there were more BDNF-containing neurons projecting to RVM being activated in the ventrolateral PAG (vlPAG than other subregions of PAG. The neurochemical properties of BDNF-containing projection neurons in the vlPAG were investigated. BDNF-containing projection neurons expressed auto receptor Tropomyosin-related kinase B (TrkB in addition to serotonin (5-HT, neurotensin (NT, substance P (SP, calcitonin gene related peptide (CGRP, nitric oxide synthase (NOS, and parvalbumin (PV but not tyrosine decarboxylase (TH. It is speculated that BDNF released from projection neurons in the vlPAG might participate in the descending pain modulation through enhancing the presynaptic release of other neuroactive substances (NSs in the RVM.

  15. Is there Equity in Use of Healthcare Services among immigrants, their descendents, and ethnic Danes?

    DEFF Research Database (Denmark)

    Nielsen, Signe Smith; Hempler, Nana Folmann; Waldorff, Frans Boch

    2012-01-01

    were linked to registries on healthcare utilization. Using Poisson regression models, contacts to hospital, emergency room (ER), general practitioner (GP), specialist in private practice, and dentist were estimated. Analyses were adjusted for health symptoms, sociodemographic factors, and proxies...... of integration. Results: In adjusted analyses, immigrants and their descendents had increased use of ER (multiplicative effect=1.19–5.02 dependent on immigrant and descendent group) and less frequent contact to dentist (multiplicative effect=0.04–0.80 dependent on the group). For hospitalization, GP......, and specialist doctor, physical health symptoms had positive but different explanatory effects within groups; however, most immigrant and descendent groups had increased use of services compared with that of ethnic Danes. Socioeconomic position and integration had no systematic effect on the use in the different...

  16. Comparison of frailty among Japanese, Brazilian Japanese descendants and Brazilian community-dwelling older women.

    Science.gov (United States)

    Sampaio, Priscila Yukari Sewo; Sampaio, Ricardo Aurélio Carvalho; Yamada, Minoru; Ogita, Mihoko; Arai, Hidenori

    2015-06-01

    To investigate frailty in Japanese, Brazilian Japanese descendants and Brazilian older women. The collected data included sociodemographic and health-related characteristics, and the frailty index Kihon Checklist. We analyzed the differences between the mean scores of Kihon Checklist domains (using ancova) and the percentage of frail women (using χ(2)-test). We carried out a binary logistic regression with Kihon Checklist domains. A total of 211 participants (Japanese n = 84, Brazilian Japanese descendants n = 55, Brazilian n = 72) participated in this research. The Brazilian participants had the highest total Kihon Checklist scores (more frail), whereas the Brazilian Japanese descendants had the lowest scores (P Brazilian group had more participants with oral dysfunction (P Brazilian women were likely to be more frail than the participants in other groups. More than the environment itself, the lifestyle and sociodemographic conditions could affect the frailty of older Brazilian women. © 2014 Japan Geriatrics Society.

  17. Descending pain modulation and its interaction with peripheral sensitization following sustained isometric muscle contraction in fibromyalgia

    DEFF Research Database (Denmark)

    Ge, H-Y; Nie, Hongling; Graven-Nielsen, Thomas

    2012-01-01

    OBJECTIVE: Sustained isometric muscle contraction (fatiguing contraction) recruits segmental and/or extrasegmental descending inhibition in healthy subjects but not in fibromyalgia (FM). We hypothesized that fatiguing contraction may shift descending pain modulation from inhibition towards...... facilitation and that the effect of descending pain modulation be dependent on peripheral muscle pain sensitivity. METHODS: Pressure pain thresholds (PPT) were measured from 13 points bilaterally in the upper trapezius muscle and from the mid-point bilaterally in the tibialis anterior before-, immediately......) than healthy control groups (286.2±24.1s) (P0.05). Following the contraction, PPTs were increased significantly and heterogeneously in the upper trapezius over time, but not, in the tibialis anterior muscle in healthy controls. However, PPT were significantly decreased over time in the tibialis...

  18. From Dark to Light to Fluorescence Resonance Energy Transfer (FRET): Polarity-Sensitive Aggregation-Induced Emission (AIE)-Active Tetraphenylethene-Fused BODIPY Dyes with a Very Large Pseudo-Stokes Shift.

    Science.gov (United States)

    Şen, Esra; Meral, Kadem; Atılgan, Serdar

    2016-01-11

    The work presented herein is devoted to the fabrication of large Stokes shift dyes in both organic and aqueous media by combining dark resonance energy transfer (DRET) and fluorescence resonance energy transfer (FRET) in one donor-acceptor system. In this respect, a series of donor-acceptor architectures of 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) dyes substituted by one, two, or three tetraphenylethene (TPE) luminogens were designed and synthesised. The photophysical properties of these three chromophore systems were studied to provide insight into the nature of donor-acceptor interactions in both THF and aqueous media. Because the generation of emissive TPE donor(s) is strongly polarity dependent, due to its aggregation-induced emission (AIE) feature, one might expect the formation of appreciable fluorescence emission intensity with a very large pseudo-Stokes shift in aqueous media when considering FRET process. Interestingly, similar results were also recorded in THF for the chromophore systems, although the TPE fragment(s) of the dyes are non-emissive. The explanation for this photophysical behaviour lies in the DRET. This is the first report on combining two energy-transfer processes, namely, FRET and DRET, in one polarity-sensitive donor-acceptor pair system. The accuracy of the dark-emissive donor property of the TPE luminogen is also presented for the first time as a new feature for AIE phenomena. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Torsion and volvulus of the transverse and descending colon in a German shepherd dog.

    Science.gov (United States)

    Halfacree, Z J; Beck, A L; Lee, K C L; Lipscomb, V J

    2006-08-01

    A German shepherd dog was presented two months after surgery for correction of acute gastric dilatation volvulus. The dog had been diagnosed with exocrine pancreatic insufficiency. Radiographs revealed marked gaseous distension of one loop of intestine with a generalised increase in intestinal gas content. A 360 degrees anticlockwise rotation of the descending and transverse colon, around the longitudinal axis of the mesocolon, was diagnosed at exploratory coeliotomy. The transverse and descending colon appeared uniformly necrotic and an end-to-end colo-colic resection and anastomosis was performed. The dog initially made satisfactory postoperative progress but was euthanased on the third postoperative day after it developed an intestinal intussusception.

  20. Seawifs Technical Report Series. Volume 2: Analysis of Orbit Selection for Seawifs: Ascending Versus Descending Node

    Science.gov (United States)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Gregg, Watson W.

    1992-01-01

    Due to range safety considerations, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) ocean color instrument may be required to be launched into a near-noon descending node, as opposed to the ascending node used by the predecessor sensor, the Coastal Zone Color Scanner (CZCS). The relative importance of ascending versus descending near-noon orbits was assessed here to determine if descending node will meet the scientific requirements of SeaWiFS. Analyses focused on ground coverage, local times of coverage, solar and viewing geometries (zenith and azimuth angles), and sun glint. Differences were found in the areas covered by individual orbits, but were not important when taken over a 16 day repeat time. Local time of coverage was also different: for ascending node orbits the Northern Hemisphere was observed in the morning and the Southern Hemisphere in the afternoon, while for descending node orbits the Northern Hemisphere was observed in the afternoon and the Southern in the morning. There were substantial differences in solar azimuth and spacecraft azimuth angles both at equinox and at the Northern Hemisphere summer solstice. Negligible differences in solar and spacecraft zenith angles, relative azimuth angles, and sun glint were obtained at the equinox. However, large differences were found in solar zenith angles, relative azimuths, and sun glint for the solstice. These differences appeared to compensate across the scan, however, an increase in sun glint in descending node over that in ascending node on the western part of the scan was compensated by a decrease on the eastern part of the scan. Thus, no advantage or disadvantage could be conferred upon either ascending node or descending node for noon orbits. Analyses were also performed for ascending and descending node orbits that deviated from a noon equator crossing time. For ascending node, afternoon orbits produced the lowest mean solar zenith angles in the Northern Hemisphere, and morning orbits produced

  1. Integration of Descending Command Systems for the Generation of Context-Specific Locomotor Behaviors

    Directory of Open Access Journals (Sweden)

    Linda H. Kim

    2017-10-01

    Full Text Available Over the past decade there has been a renaissance in our understanding of spinal cord circuits; new technologies are beginning to provide key insights into descending circuits which project onto spinal cord central pattern generators. By integrating work from both the locomotor and animal behavioral fields, we can now examine context-specific control of locomotion, with an emphasis on descending modulation arising from various regions of the brainstem. Here we examine approach and avoidance behaviors and the circuits that lead to the production and arrest of locomotion.

  2. Kinematic compensations as children reciprocally ascend and descend stairs with unilateral and bilateral solid AFOs.

    Science.gov (United States)

    Nahorniak, M T; Gorton GE3rd; Gannotti, M E; Masso, P D

    1999-07-01

    The aim of this study was to identify the compensations made when a child with normal motor control ascends and descends stairs while wearing a solid AFO. Ten healthy children were asked to ascend and descend stairs with shoes, right and bilateral AFOs. Repeated measures ANOVA identified differences in selected kinematic parameters. Peak-to-peak excursion of pelvic rotation, pelvic obliquity, and hip ab/adduction increased with AFO use (PAFO use (P<0.05). Compensations at the trunk and the pelvis facilitated limb advancement and clearance. This information may be helpful in developing strategies for training patients with motor planning difficulties.

  3. Control of abdominal muscles by brain stem respiratory neurons in the cat.

    Science.gov (United States)

    Miller, A D; Ezure, K; Suzuki, I

    1985-07-01

    Control of abdominal musculature by brain stem respiratory neurons was studied in decerebrate unanesthetized cats by determining 1) which brain stem respiratory neurons could be antidromically activated from the lumbar cord, from which the abdominal muscles receive part of their innervation, and 2) if lumbar-projecting respiratory neurons make monosynaptic connections with abdominal motoneurons. A total of 462 respiratory neurons, located between caudal C2 and the retrofacial nucleus (Bötzinger complex), were tested for antidromic activation from the upper lumbar cord. Fifty-eight percent of expiratory (E) neurons (70/121) in the caudal ventral respiratory group (VRG) between the obex and rostral C1 were antidromically activated from contralateral L1. Eight of these neurons were activated at low thresholds from lamina VIII and IX in the L1-2 gray matter. One-third (14/41) of the E neurons that projected to L1 could also be activated from L4-5. Almost all antidromic E neurons had an augmenting firing pattern. Ten scattered inspiratory (I) neurons projected to L1 but could not be activated from L4-5. No neurons that fired during both E and I phases (phase-spanning neurons) were antidromically activated from the lumbar cord. In order to test for possible monosynaptic connections between descending E neurons and abdominal motoneurons, cross-correlations were obtained between 27 VRG E neurons, which were antidromically activated from caudal L2 and contralateral L1 and L2 abdominal nerve activity (47 neuron-nerve combinations). Only two neurons showed a correlation with one of the two nerves tested. Although there is a large projection to the lumbar cord from expiratory neurons in the ventral respiratory group caudal to the obex, cross-correlation analyses suggest that strong monosynaptic connections between these neurons and abdominal motoneurons are scarce.

  4. Regeneration of descending spinal axons after transection of the thoracic spinal cord during early development in the North American opossum, Didelphis virginiana.

    Science.gov (United States)

    Martin, G F; Terman, J R; Wang, X M

    2000-11-15

    Opossums are born in an immature, fetal-like state, making it possible to lesion their spinal cord early in development without intrauterine surgery. When the thoracic spinal cord of the North American opossum, Didelphis virginiana, is transected on postnatal day 5, and injections of Fast Blue (FB) are made caudal to the lesion site 30-40 days or 6 months later, neurons are labeled in all of the spinal and supraspinal areas that are labeled after comparable injections in age-matched, unlesioned controls. Double-labeling studies document that regeneration of cut axons contributes to growth of axons through the lesion site and behavioral studies show that animals lesioned on postnatal day 5 use their hindlimbs in normal appearing locomotion as adults. The critical period for developmental plasticity of descending spinal axons extends to postnatal day 26, although axons which grow through the lesion site become fewer in number and more restricted as to origin with increasing age. Animals lesioned between postnatal day 12 and 26 use the hindlimbs better than animals lesioned as adults, but hindlimb function is markedly abnormal and uncoordinated with that of the forelimbs. We conclude that restoration of anatomical continuity occurs after transection of the spinal cord in developing opossums, that descending axons grow through the lesion site, that regeneration of cut axons contributes to such growth, and that animals lesioned early enough in development have relatively normal motor function as adults.

  5. Polarization sensitive optical coherence tomography in dentistry

    International Nuclear Information System (INIS)

    Dichtl, S.

    1998-01-01

    Optical coherence tomography (OCT) is a noninvasive and noncontact technique for obtaining cross-sectional images of biologic structure, which was initially introduced to depict the transparent tissue of the eye. It employs the partial coherence properties of a light source to image structures with high resolution (< 20 (m). Recently, this technique has also been applied in turbid media. This tomographic imaging is analogous to conventional ultrasound B mode imaging, except that OCT measures the intensity of backreflected infrared light rather than acoustical waves. First applications, of OCT in dentistry for diagnosing periodontal disease have been reported by Colston et al. presenting in vitro OCT images of the dental and periodontal tissues of porcine premolar teeth. In this work, the feasibility of polarisation sensitive OCT for dental material is suggested. In contrast with conventional OCT, where the magnitude of backscattered light as a function of depth is imaged, backscattered light is used to image the magnitude of the birefringence in the sample as a function of depth. Partial loss of birefringence is known to be an early indication of incipient caries or tissue thermal damage. Applying this technique for caries diagnosis or guidance regarding optimal dosimetry for thermally mediated laser therapeutic procedures, polarisation sensitive OCT would represent a promising new technology for dentistry. (author)

  6. the priests and the descendants of levi in the book of malachi

    African Journals Online (AJOL)

    The article argues that the phrase “the descendants of Levi” in Mal 3:3 includes both priests and Levites and that the author of the book of Malachi was an inspired temple preacher, or writer, who probably belonged to the ranks of priests or. Levites. He was a voice of the late 5th century, who with prophetic authority, like his.

  7. the priests and the descendants of levi in the book of malachi

    African Journals Online (AJOL)

    Fanie Snyman for his hospitality and for all his generous efforts to make my stay ... This interpretation of the descendants of Levi has long since found many ...... 1998. Malachi. A New Translation with Introduction and Commentary. New. York: Doubleday. AB 25D. kessLer, r. 2011. Maleachi. Übersetzt und ausgelegt.

  8. ranching pattern of the left anterior descending coronary artery in a ...

    African Journals Online (AJOL)

    Branching pattern of the left anterior descending coronary artery is important in explaining variations in occurrence of coronary atherosclerosis, informing management strategies for coronary heart disease and interventional cardiology. Data on African populations are, however, scarce. Since coronary heart disease is ...

  9. Being one of the few : Professionally successful descendants of migrants from Turkey

    NARCIS (Netherlands)

    A. Konyali (Ali)

    2018-01-01

    textabstractDrawing on data collected through semi-structured, in-depth interviews in Germany, France, Sweden, and the Netherlands, this dissertation focuses on descendants of labour migrants from Turkey in leading professional positions. The dissertation explains how individuals from a

  10. Dual (type IV) left anterior descending artery | Baskan | SA Journal of ...

    African Journals Online (AJOL)

    Congenital coronary artery anomalies are uncommon. Dual left anterior descending coronary artery (LAD) is defined as the presence of two LADs within the anterior interventricular sulcus (AIVS), and is classified into four types. Type IV is a rarely reported subtype and differs from the others, with a long LAD originating from ...

  11. Descending inhibitory pain modulation is impaired in patients with chronic pancreatitis.

    NARCIS (Netherlands)

    Olesen, S.S.; Brock, C.; Krarup, A.L.; Funch-Jensen, P.; Arendt-Nielsen, L.; Wilder-Smith, O.H.G.; Drewes, A.M.

    2010-01-01

    BACKGROUND & AIMS: Pain is a prominent symptom in chronic pancreatitis (CP), but the underlying mechanisms are incompletely understood. We investigated the role of descending pain modulation from supraspinal structures as well as central nervous system sensitization in patients with pain from CP.

  12. [Descending necrotizing mediastinitis: the need for early diagnosis and aggressive treatment

    NARCIS (Netherlands)

    Schoenmakers, M.C.J.; Marres, H.A.M.; Merkx, M.A.W.; Verhagen, A.F.T.M.; Swieten, H.A. van

    2009-01-01

    Three patients developed descending necrotizing mediastinitis (DNM): a 44-year-old man due to poor dental status; a 54-year-old women due to a throat infection, 6 weeks after a tooth extraction; and a 30-year-old man a few days after a tooth extraction. Presenting symptoms were dyspnoea, fever,

  13. The effects of laser radiation on the descendants of irradiated rats

    International Nuclear Information System (INIS)

    Hernandez, J.W.R.; Barbosa, C.A.A.; Moderno, L.A.O.; Parizzotto, N.A.

    1991-01-01

    The effects of low energy laser radiation on the descendants of irradiated rats were investigated by comparing natimortality and the frequency of congenital malformations in three experimental and a control group. Natimortality was not significantly different among the groups. However, cardiomegaly, anophtalmia, dilated abdominal viscera, and premature closures of cranial sutures were recorded only in the experimental groups. (author)

  14. Deep Neck Infection and Descending Mediastinitis as a Complication of Propionibacterium acnes Odontogenic Infection

    OpenAIRE

    Brotfain, Evgeni; Koyfman, Leonid; Saidel-Odes, Lisa; Borer, Abraham; Refaely, Yael; Klein, Moti

    2015-01-01

    Propionibacterium acnes is an anaerobic, Gram-positive bacterium which causes numerous types of infections. Isolated Propionibacterium acnes deep neck infections are very rare. We present an interesting case of deep neck infection complicated by descending mediastinitis of isolated Propionibacterium acnes infection.

  15. Exploring the potential of the descending-point method to measure ...

    African Journals Online (AJOL)

    Therefore, in Karoo veld, resting may be considered a more practicable veld management strategy than attempts to achieve a specific utilization intensity. The descending-point method is time-consuming in determining canopy cover. Thus, methods based on more effective point sampling, within the canopy spread, may be ...

  16. Astronaut Edwin Aldrin descends steps of Lunar Module ladder to walk on moon

    Science.gov (United States)

    1969-01-01

    Astronaut Edwin E. Aldrin Jr., lunar module pilot, descends the steps of the Lunar Module (LM) ladder as he prepares to walk on the Moon. He had just egressed the LM. This picture was taken by Astronaut Neil A. Armstrong, commander, with a 70mm lunar surface camera.

  17. Deep Neck Infection and Descending Mediastinitis as a Complication of Propionibacterium acnes Odontogenic Infection

    Directory of Open Access Journals (Sweden)

    Evgeni Brotfain

    2015-01-01

    Full Text Available Propionibacterium acnes is an anaerobic, Gram-positive bacterium which causes numerous types of infections. Isolated Propionibacterium acnes deep neck infections are very rare. We present an interesting case of deep neck infection complicated by descending mediastinitis of isolated Propionibacterium acnes infection.

  18. Cartographies of the Political Camp of Afro-Descendents in Latin America

    Directory of Open Access Journals (Sweden)

    Agustín Lao-Montes

    2009-07-01

    Full Text Available This article lays out, in general terms, what it calls the political camp of Afro-descendents in Latin America. After establishing a series of theoretical and methodological criteria for the historical analysis of black movements in modernity and the Afro-American movements in particular, the article focuses on the emergence of afro-descendant movements in Latin America during the last part of the 1980s. One of the principal arguments is that in the 1990s a political camp of afro-descendents starts to emerge in the region of Latin America based on a series of developments, including the emergence of new social movements that included ethno-racial movements of Afros and indigenous people, events of regional importance like the contra-celebration of 1492 in 1992, the World Conference against Racism 2001 in Durban, South Africa, and the effects of the neoliberal pattern of globalization. The political camp of Afro-descendents is composed not only of social movements, but also of state actors and transnational actors (such as the World Bank and the Ford Foundation. The article concludes with an analysis of the challenges and perspectives of Afro-American politics in general and of Afro-Latin movements in particular considering the current crisis of the modern/colonial world-system.

  19. Descending motor pathways and the spinal motor system. Limbic and non-limbic components

    NARCIS (Netherlands)

    G. Holstege (Gert)

    1990-01-01

    textabstractFor a thorough understanding of the descending pathways of the motor system originating in the forebrain, knowledge about the anatomy and function of the structures in the more caudally located parts of the central nervous system is indispensable. In this paper an overview will be

  20. Are immigrants and descendants with ill health more prone to unemployment? Evidence from 18 European countries.

    Science.gov (United States)

    Heggebø, Kristian

    2017-08-01

    Previous research has established that both ill health and minority status are associated with unemployment. Less is known, however, about the interplay between having ill health and being from minority background. The present study examines whether immigrants and descendants with ill health are particularly prone to unemployment during an economic downturn in Europe. The European Union Statistics on Income and Living Conditions (EU-SILC) cross-sectional data material is utilized, and linear probability models are estimated. The analysis is run for countries in which the two minority samples are acceptably large (N ≥ 100), resulting in 18 included European countries. The year 2011 is chosen because it is possible to identify both immigrants and descendants in EU-SILC due to a module on intergenerational transfer of disadvantages. The results indicate - as expected - that both ill health and minority status are independently related to higher unemployment likelihood. Immigrants and descendants with ill health, however, are not particularly likely to be unemployed. This finding is robust to a number of sensitivity tests, and the empirical pattern is very similar across the 18 included countries. Both minority status and ill health are associated with high unemployment probability in Europe. However, there does not seem to exist a 'double disadvantage' for immigrants and descendants with ill health, which is in line with a human capital perspective on how employers evaluate potential employees. Both a non-native-sounding name and bad health status are interpreted as a risk factor, but there is no reason to expect ill health to lower the productivity level more if the applicant is a descendant or immigrant.

  1. NEURON and Python

    OpenAIRE

    Michael Hines; Andrew P Davison; Eilif Muller

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because ...

  2. Activity in neurons of a putative protocerebral circuit representing information about a ten component plant odour blend in Heliothis virescens.

    Directory of Open Access Journals (Sweden)

    Bjarte Bye Løfaldli

    2012-09-01

    Full Text Available The olfactory pathway in the insect brain is anatomically well described from the antennal lobe to the mushroom bodies and the lateral protocerebrum in several species. Less is known about the further connections of the olfactory network in protocerebrum and how information about relevant plant odorants and mixtures are represented in this network, resulting in output information mediated by descending neurons. In the present study we have recorded intracellularly followed by dye injections from neurons in the lateral- and superior protocerebrum of the moth, Heliothis virescens. As relevant stimuli, we have used selected primary plant odorants and mixtures of them. The results provide the morphology and physiological responses of neurons involved in a putative circuit connecting the mushroom body lobes, the superior and the lateral protocerebrum, as well as input to superior and lateral protocerebrum by one multiglomerular antennal lobe neuron and output from the lateral protocerebrum by one descending neuron. All neurons responded to one particular mixture of ten primary plant odorants, some of them also to single odorants of the mixture. Altogether, the physiological data indicate integration in protocerebral neurons of information from several of the receptor neuron types functionally described in this species.

  3. Ectopic paragonimiasis on colon wall and mesocolon of the descending colon

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Hae Jeong; Hong, Kyung Chun; Chung, Hye Kyung; Suh, Won Hyuck [Korea University College of Medicine, Seoul (Korea, Republic of)

    1983-06-15

    Paragonimiasis is prevalent in Far East and a kind of endemic Korean diseases. The primary site of human paragonimiasis is the lung, but the ectopic infection of lung fluke has been reported by many authors. We experienced one case of abdominal paragonimiasis in a 44 year old male with a complaint of left lower quadrant pain. Physical examination, barium enema, and other data suggested the possibility of tumor originating from the wall of descending colon. (intramural tumor). Postoperative specimen taken from the solid tumorous lesion showed parasitic granuloma, characteristic of Paragonimus Westermani. Here, we report a cases of very peculiar ectopic paragonimiasis involved descending colon wall simulating neoplastic tumor, and also review the literatures briefly.

  4. Papillary Adenocarcinoma of the descending colon in a dog: case report

    Directory of Open Access Journals (Sweden)

    M.G.P.A. Ferreira

    Full Text Available ABSTRACT The aim of this report was to describe the clinical findings and therapeutic management of a case of papillary adenocarcinoma of the descending colon in a Beagle. The patient presented soft stools, haematochezia, tenesmus, and dyschezia. Clinical examination revealed alterations on the ultrasonographic features of the descending colon suggestive of colitis and neoplasia. Following local mass resection, histopathology analysis revealed mild lymphoplasmocytic enteritis and papillary adenocarcinoma of the colon. Enterectomy for tumoral resection and biopsy of locoregional lymph nodes were carried out. Subsequent to the surgical procedure, it was possible to confirm the previous diagnosis and the tumor was classified as intestinal intraluminal papillary adenocarcinoma, with incomplete surgical margins. Adjuvant chemotherapy was performed using carboplatin, cyclophosphamide, and piroxicam, leading to remission of clinical signs and absence of any clinical or imaging alterations compatible with the patient’s previous clinical condition.

  5. Descending necrotizing mediastinitis following dental extraction. Radiological features and surgical treatment considerations.

    Science.gov (United States)

    González-García, Raúl; Risco-Rojas, Roberto; Román-Romero, Leticia; Moreno-García, Carlos; López García, Cipriano

    2011-07-01

    Descending necrotizing mediastinitis (DNM) following dental extraction is an extremely serious infection with a high mortality rate. Oral infection may rapidly descend into the mediastinum across the retropharyngeal and retrovisceral spaces. Once established, mediastinitis is rapidly followed by sepsis and death. If DNM is suspected cervical and thoracic CT must be carried out urgently. After this, prompt control of the upper airway with tracheostomy, aggressive surgical debridement of the deep cervical spaces and mediastinum, and intravenous broad spectrum antibiotic therapy are mandatory. The present paper reports two new cases of DNM following dental extraction, and focuses on radiological features of abscess progression through the cervical spaces down into the mediastinum. 2010 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  6. Chediak-Higashi syndrome: case report in afro-descendant individual

    OpenAIRE

    Carlos, Judde Lacerda Andrade; Oliveira, Márcio Vasconcelos; Souza, Claudio Lima

    2014-01-01

    This is a Chediak-Higashi Syndrome (CHS) case report in afro-descendant individual, male, 3 months old, born from consanguineous union. On admission he had fever for a month, unresolved pneumonia, and hepatosplenomegaly. He evolved to bacterial sepsis, septic shock, and death. CHS presents quantitative and morphological and hematological changes. Abnormal leukocyte inclusions are the pathognomonic finding of the disease; its recognition and differentiation from other leukocyte inclusions is e...

  7. The priests and the descendants of Levi in the Book of Malachi ...

    African Journals Online (AJOL)

    The article argues that the phrase “the descendants of Levi” in Mal 3:3 includes both priests and Levites and that the author of the book of Malachi was an inspired temple preacher, or writer, who probably belonged to the ranks of priests or Levites. He was a voice of the late 5th century, who with prophetic authority, like his ...

  8. An anatomic and clinical study of the adductor magnus tendon-descending genicular artery bone flap.

    Science.gov (United States)

    Huang, Dong; Wang, Hai-Wen; Xu, Da-Chuan; Wang, Hong-Gang; Wu, Wei-Zhi; Zhang, Hui-Ru

    2011-01-01

    The composite tissue flap of the descending genicular vessels with the adductor magnus tendon is a newly developed, reliable method to repair the Achilles tendon and relevant skin defects. The aim of this study was to evaluate the anatomy of the adductor magnus tendon-descending genicular artery bone flap, and the feasibility and value for the repair of the Achilles tendon and relevant skin defects. There were 34 adult specimens used for the anatomy of this flap. The descending genicular artery originates 10.5 ± 1.6 cm above the adductor tubercle, with a diameter of 1.8 ± 0.6 mm and a length of 1.2 ± 0.5 cm. Its articular branch is distributed in the adductor magnus tendon and the medial condyle of the femur. The saphenous branch has a diameter of 1.1 ± 0.3 mm and is distributed in the skin of the upper medial calf. A total of 16 cases of trauma-induced Achilles tendon damage and calcaneus and skin defects were repaired with the vascularized adductor magnus tendon bone flap, including the reconstruction of Achilles tendon insertion and repair of relevant skin defects. All of the composite tissue flaps were viable, the skin sensation of the flaps was recovered, and all patients walked with a normal gait. Our results suggested that the adductor magnus tendon-descending genicular artery bone flap is an alternative method to repair composite tissue defects of the Achilles tendon. Copyright © 2010 Wiley-Liss, Inc.

  9. Curative effect of endoscopic resection in non-ampullary descending duodenal tubulovillous adenoma

    Directory of Open Access Journals (Sweden)

    Zhi-feng ZHAO

    2013-11-01

    Full Text Available Objective To assess the curative effect of endoscopic resection in patients with non-ampullary descending duodenal tubulovillous adenoma. Methods The clinical data of 9 patients with non-ampullary descending duodenal tubulovillous adenoma from Jan. 2004 to Dec. 2012 in the Department of Endoscopy of General Hospital of Shenyang Command were retrospectively reviewed. All patients were diagnosed with endoscopy, ultrasound endoscopy and preoperative pathology, and all of them underwent endoscopic dissection. Pathological examination and follow-up were carried out after operation. Results Nine patients, including 4 men and 5 women aged 45-78 (59.6±11.5 years old were involved. Tubulovillous adenomas were found in descending duodenum of all patients, with the size of 1.8 to 2.5cm, with a mean of 2.03±0.24cm. Endoscopic resection (EMR was used in all patients successfully. No complication was found during operation and after operation. Postoperative pathology confirmed that all the tumors were tubulovillous adenomas. Low-grade intraepithelial neoplasia was found in 4 cases, and high-grade in 5 cases. Mucosal focal carcinoma was confirmed in one case, without involvement of muscularis mucosae. The position emission tomography (PET showed no abnormal radionuclide accumulation. There were no hemorrhage or death during and after the operation. The average follow-up time was 6-58 (25.6±16.4 months. Metastases and recurrence had not been found. Conclusion Endoscopic mucosal resection is a safe, adequate method for non-ampullary descending duodenal tubulovillous adenomas. DOI: 10.11855/j.issn.0577-7402.2013.11.012

  10. Histamine in the locus coeruleus promotes descending noradrenergic inhibition of neuropathic hypersensitivity.

    Science.gov (United States)

    Wei, Hong; Jin, Cong-Yu; Viisanen, Hanna; You, Hao-Jun; Pertovaara, Antti

    2014-12-01

    Among brain structures receiving efferent projections from the histaminergic tuberomammillary nucleus is the pontine locus coeruleus (LC) involved in descending noradrenergic control of pain. Here we studied whether histamine in the LC is involved in descending regulation of neuropathic hypersensitivity. Peripheral neuropathy was induced by unilateral spinal nerve ligation in the rat with a chronic intracerebral and intrathecal catheter for drug administrations. Mechanical hypersensitivity in the injured limb was assessed by monofilaments. Heat nociception was assessed by determining radiant heat-induced paw flick. Histamine in the LC produced a dose-related (1-10μg) mechanical antihypersensitivity effect (maximum effect at 15min and duration of effect 30min), without influence on heat nociception. Pretreatment of LC with zolantidine (histamine H2 receptor antagonist), but not with pyrilamine (histamine H1 receptor antagonist), and spinal administration of atipamezole (an α2-adrenoceptor antagonist), prazosine (an α1-adrenoceptor antagonist) or bicuculline (a GABAA receptor antagonist) attenuated the antihypersensitivity effect of histamine. The histamine-induced antihypersensitivity effect was also reduced by pretreatment of LC with fadolmidine, an α2-adrenoceptor agonist inducing autoinhibition of noradrenergic cell bodies. Zolantidine or pyrilamine alone in the LC failed to influence pain behavior, while A-960656 (histamine H3 receptor antagonist) suppressed hypersensitivity. A plausible explanation for these findings is that histamine, due to excitatory action mediated by the histamine H2 receptor on noradrenergic cell bodies, promotes descending spinal α1/2-adrenoceptor-mediated inhibition of neuropathic hypersensitivity. Blocking the autoinhibitory histamine H3 receptor on histaminergic nerve terminals in the LC facilitates release of histamine and thereby, increases descending noradrenergic pain inhibition. Copyright © 2014 Elsevier Ltd. All rights

  11. Supracardiac total anomalous pulmonary venous connection with a descending vertical vein.

    Science.gov (United States)

    Shah, Sejal; Singh, Mukesh; John, Colin; Maheshwari, Sunita

    2009-10-01

    The commonly used Darling classification for total anomalous pulmonary venous connection (TAPVC) consists of supracardiac, cardiac, infracardiac, and mixed types (Craig et al., Lab Invest 6:44-64, 1967). In supracardiac TAPVC, the common pulmonary vein drains superiorly into the left innominate vein, the superior vena cava, or the azygos vein by way of an ascending vertical vein. We describe a case of supracardiac TAPVC draining into the azygos vein atypically by way of a descending vertical vein.

  12. Resection of left anterior descending coronary artery aneurysm on a beating heart.

    Science.gov (United States)

    Misthos, P; Kokotsakis, J N; Lioulias, A G; Skouteli, E A

    2009-01-01

    We report on the case of a 65-year-old man with unstable angina due to a left anterior descending (LAD) coronary artery single aneurysm. On a beating heart, the aneurysm was partially resected and the left internal thoracic artery was grafted in situ as a patch to the LAD opening. The patient remains well and free of symptoms two years after the operation.

  13. Telecast of Astronaut Neil Armstrong descending ladder to surface of the moon

    Science.gov (United States)

    1969-01-01

    Astronaut Neil A. Armstrong, Apollo 11 commander, descends the ladder of the Apollo 11 Lunar Module prior to making the first step by man on the moon. This view is a black and white reproduction taken from a telecast by the Apollo 11 lunar surface camera during extravehicular activity. The black bar running through the center of the picture is an anamoly in the television ground data system at the Goldstone Tracking Station.

  14. Traumatic Left Anterior Descending Coronary Artery-Right Ventricle Fistula: A Case Report

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Sheikhi

    2011-06-01

    Full Text Available Traumatic coronary artery-cameral fistulas (TCAF are rare and may present secondary to penetrating injuries (80% or iatrogenic traumas. Early operative intervention remains the recommended treatment modality for accidental traumatic coronary artery fistulas. We report the case of a 17-year-old man who presented with left anterior descending coronary artery-right ventricle fistula following penetrating cardiac trauma, which was successfully repaired surgically.

  15. Traumatic Left Anterior Descending Coronary Artery-Right Ventricle Fistula: A Case Report

    Directory of Open Access Journals (Sweden)

    Alireza Rezaee

    2011-05-01

    Full Text Available Traumatic coronary artery-cameral fistulas (TCAF are rare and may present secondary to penetrating injuries (80%or iatrogenic traumas. Early operative intervention remains the recommended treatment modality for accidental traumatic coronary artery fistulas. We report the case of a 17-year-old man who presented with left anterior descending coronary artery-right ventricle fistula following penetrating cardiac trauma, which was successfully repaired surgically.

  16. Factors influencing the mechanical behaviour of healthy human descending thoracic aorta

    International Nuclear Information System (INIS)

    Guinea, Gustavo V; Atienza, José M; Rojo, Francisco J; Yiqun, Li; Claes, Els; Elices, Manuel; García-Herrera, Claudio M; Goicolea, José M; García-Montero, Carlos; Burgos, Raúl L; Goicolea, Francisco J

    2010-01-01

    In recent times, significant effort has been made to understand the mechanical behaviour of the arterial wall and how it is affected by the different vascular pathologies. However, to be able to interpret the results correctly, it is essential that the influence of other factors, such as aging or anisotropy, be understood. Knowledge of mechanical behaviour of the aorta has been customarily constrained by lack of data on fresh aortic tissue, especially from healthy young individuals. In addition, information regarding the point of rupture is also very limited. In this study, the mechanical behaviour of the descending thoracic aorta of 28 organ donors with no apparent disease, whose ages vary from 17 to 60 years, is evaluated. Tensile tests up to rupture are carried out to evaluate the influence of age and wall anisotropy. Results reveal that the tensile strength and stretch at failure of healthy descending aortas show a significant reduction with age, falling abruptly beyond the age of 30. This fact places age as a key factor when mechanical properties of descending aorta are considered

  17. [Descending hypoglossal branch-facial nerve anastomosis in treating unilateral facial palsy after acoustic neuroma resection].

    Science.gov (United States)

    Liang, Jiantao; Li, Mingchu; Chen, Ge; Guo, Hongchuan; Zhang, Qiuhang; Bao, Yuhai

    2015-12-15

    To evaluate the efficiency of the descending hypoglossal branch-facial nerve anastomosis for the severe facial palsy after acoustic neuroma resection. The clinical data of 14 patients (6 males, 8 females, average age 45. 6 years old) underwent descending hypoglossal branch-facial nerve anastomosis for treatment of unilateral facial palsy was analyzed retrospectively. All patients previously had undergone resection of a large acoustic neuroma. House-Brackmann (H-B) grading system was used to evaluate the pre-, post-operative and follow up facial nerve function status. 12 cases (85.7%) had long follow up, with an average follow-up period of 24. 6 months. 6 patients had good outcome (H-B 2 - 3 grade); 5 patients had fair outcome (H-B 3 - 4 grade) and 1 patient had poor outcome (H-B 5 grade) Only 1 patient suffered hemitongue myoparalysis owing to the operation. Descending hypoglossal branch-facial nerve anastomosis is effective for facial reanimation, and it has little impact on the function of chewing, swallowing and pronunciation of the patients compared with the traditional hypoglossal-facial nerve anastomosis.

  18. Mitochondrial DNA mapping of social-biological interactions in Brazilian Amazonian African-descendant populations

    Directory of Open Access Journals (Sweden)

    Bruno Maia Carvalho

    2008-01-01

    Full Text Available The formation of the Brazilian Amazonian population has historically involved three main ethnic groups, Amerindian, African and European. This has resulted in genetic investigations having been carried out using classical polymorphisms and molecular markers. To better understand the genetic variability and the micro-evolutionary processes acting in human groups in the Brazilian Amazon region we used mitochondrial DNA to investigate 159 maternally unrelated individuals from five Amazonian African-descendant communities. The mitochondrial lineage distribution indicated a contribution of 50.2% from Africans (L0, L1, L2, and L3, 46.6% from Amerindians (haplogroups A, B, C and D and a small European contribution of 1.3%. These results indicated high genetic diversity in the Amerindian and African lineage groups, suggesting that the Brazilian Amazonian African-descendant populations reflect a possible population amalgamation of Amerindian women from different Amazonian indigenous tribes and African women from different geographic regions of Africa who had been brought to Brazil as slaves. The present study partially mapped the historical biological and social interactions that had occurred during the formation and expansion of Amazonian African-descendant communities.

  19. Clinical outcomes of laparoscopic surgery for transverse and descending colon cancers in a community setting.

    Science.gov (United States)

    Matsuda, Takeru; Fujita, Hirofumi; Kunimoto, Yukihiro; Kimura, Taisei; Hayashi, Tomomi; Maeda, Toshiyuki; Yamakawa, Junichi; Mizumoto, Takuya; Ogino, Kazunori

    2013-08-01

    The feasibility, safety and oncological outcomes of laparoscopic surgery for transverse and descending colon cancers in a community hospital setting were evaluated. Twenty-six patients with transverse or descending colon cancers who underwent laparoscopic surgery at our hospital were included in this retrospective analysis (group A). Their outcomes were compared with those of 71 patients who underwent laparoscopic surgery for colon cancer at other tumor sites (group B). There were no significant differences between the two groups in terms of operative time, estimated blood loss, postoperative hospital stay and morbidity rate. Extended lymphadenectomy was performed more frequently and the number of harvested lymph nodes was significantly higher in group B than in group A. However, no recurrence developed in group A, while recurrence occurred in four patients from group B. The 3-year disease-free survival rates were 100% for group A and 93.5% for group B. The 3-year overall survival rates were 100% for group A and 91.6% for group B. Laparoscopic surgery for transverse and descending colon cancers can be performed safely with oncological validity in a community hospital setting, provided there is careful selection of the patients and adequate lymphadenectomy considering the clinical stage of their disease. © 2013 Japan Society for Endoscopic Surgery, Asia Endosurgery Task Force and Wiley Publishing Asia Pty Ltd.

  20. Opportunities for mourning when grief is disenfranchised: descendants of Nazi perpetrators in dialogue with Holocaust survivors.

    Science.gov (United States)

    Livingston, Kathy

    2010-01-01

    This article explores the concepts of unmourned and disenfranchised grief as a way to understand the experiences of adult children of Nazi perpetrators, who grew up with cultural norms of grieving alone or in silence. The scholarly literature on descendants of Nazis reflects a group unlikely to warrant empathy or support from others because of the stigma surrounding their family's possible involvement in the Holocaust atrocities. This article uses, as a case study approach, the testimony given by Monika Hertwig, the adult daughter of a high ranking Nazi, who appears in the documentary film, Inheritance. From the perspective of disenfranchised grief, defined as grief that is not socially recognized or supported, the article links Monika's testimony with existing research from in-depth interviews with other descendants of Nazis to suggest that, as a group, they lacked permission to grieve their deceased parents, acknowledgment of their grief, and opportunities to mourn. Based on the theory that the effects of grief can be transgenerational, the disenfranchisement experienced by the "children of the Third Reich" does not have to pass to subsequent generations if opportunities for mourning are made possible and some resolution of grief occurs. Studies have shown that ongoing dialogue groups between Holocaust survivors and descendants of Nazis provide opportunities for mourning to both groups.

  1. Cervical necrotising fasciitis and descending mediastinitis secondary to unilateral tonsillitis: a case report

    Directory of Open Access Journals (Sweden)

    Islam Asad

    2008-12-01

    Full Text Available Abstract Introduction Cervical necrotizing fasciitis is an aggressive infection with high morbidity and mortality. We present a case of cervical necrotizing fasciitis and descending mediastinitis in a healthy young man, caused by unilateral tonsillitis with a successful outcome without aggressive debridement. Case presentation A 41-year-old man was admitted to our unit with a diagnosis of severe acute unilateral tonsillitis. On admission, he had painful neck movements and the skin over his neck was red, hot and tender. Computed tomography scan of his neck and chest showed evidence of cervical necrotizing fasciitis and descending mediastinitis secondary to underlying pharyngeal disease. He was treated with broad-spectrum intravenous antibiotics. His condition improved over the next 3 days but a tender and fluctuant swelling appeared in the suprasternal region. A repeat scan showed the appearance of an abscess extending from the pretracheal region to the upper mediastinum which was drained through a small transverse anterior neck incision. After surgery, the patient's condition quickly improved and he was discharged on the 18th day of admission. Conclusion Less invasive surgical techniques may replace conventional aggressive debridement as the treatment of choice for cervical necrotizing fasciitis and descending necrotizing mediastinitis.

  2. Descending aorta-to-femoral artery bypass: preliminary experience with a thoracoscopic technique.

    Science.gov (United States)

    Kolvenbach, R; Da Silva, L; Schwierz, E; Deling, O

    2000-04-01

    Descending aorta-to-femoral artery bypass is a durable procedure with excellent long-term patency rates. The operation is usually performed using a lateral thoracotomy combined with retroperitoneal tunneling of the graft. Assuming that a smaller incision would reduce the operative trauma, minimally invasive video endoscopic techniques were used to perform a thoracoscopic bypass operation. In all patients, exposure of the descending aorta was obtained using thoracoscopy. This was accomplished with a maximum of four ports. For placing the conventional side-biting aortic clamp, a 3- to 4-cm incision was necessary. Using this incision as an access port, the proximal anastomosis was sutured endoscopically. Retroperitoneal tunneling was performed using laparoscopically guided balloon dissection. Eleven consecutive patients underwent surgery. In two patients, conversion to a standard thoracotomy was necessary because of extensive intrathoracic adhesions. There were no major complications, except for one hematoma. After a mean follow-up of 9.5 months, all bypass grafts were still patent. Patients could be discharged after a mean postprocedural hospital stay of 7.4 days (range, 5-12). Thoracoscopic descending aorta-to-femoral artery bypass is an operation with excellent patency rates; however, it is a novel technique that still requires further technical improvements. Clinical studies are needed to prove the safety and efficacy of this minimally invasive technique.

  3. Descending pain modulation in irritable bowel syndrome (IBS): a systematic review and meta-analysis.

    Science.gov (United States)

    Chakiath, Rosemary J; Siddall, Philip J; Kellow, John E; Hush, Julia M; Jones, Mike P; Marcuzzi, Anna; Wrigley, Paul J

    2015-12-10

    Irritable bowel syndrome (IBS) is a common functional gastrointestinal disorder. While abdominal pain is a dominant symptom of IBS, many sufferers also report widespread hypersensitivity and present with other chronic pain conditions. The presence of widespread hypersensitivity and extra-intestinal pain conditions suggests central nervous dysfunction. While central nervous system dysfunction may involve the spinal cord (central sensitisation) and brain, this review will focus on one brain mechanism, descending pain modulation. We will conduct a comprehensive search for the articles indexed in the databases Ovid MEDLINE, Ovid Embase, Ovid PsycINFO and Cochrane Central Register of Controlled Trial (CENTRAL) from their inception to August 2015, that report on any aspect of descending pain modulation in irritable bowel syndrome. Two independent reviewers will screen studies for eligibility, assess risk of bias and extract relevant data. Results will be tabulated and, if possible, a meta-analysis will be carried out. The systematic review outlined in this protocol aims to summarise current knowledge regarding descending pain modulation in IBS. PROSPERO CRD42015024284.

  4. Effects of Descending Stair Walking on Health and Fitness of Elderly Obese Women.

    Science.gov (United States)

    Chen, Trevor C; Hsieh, Chung-Chan; Tseng, Kuo-Wei; Ho, Chih-Chiao; Nosaka, Kazunori

    2017-08-01

    Eccentric exercise training produces positive fitness and health outcomes, but whether this is also the case for descending stair walking (DSW) is unknown. This study investigated the hypothesis that DSW would improve insulin sensitivity, lipid profiles and physical fitness better than ascending stair walking (ASW). Elderly (≥60 yr) obese women were placed to either DSW or ASW group (n = 15 per group). An elevator was used to eliminate ascending stairs for DSW, and descending stairs for ASW. Descending stair walking and ASW were performed twice a week for 12 wk by increasing the repetitions gradually. Overnight fasting blood samples were taken 3 d before the first training session and 4 d after the last training session, and analyzed for insulin sensitivity and lipid profile markers. Resting HR, systolic blood pressure, and diastolic blood pressure, bone mineral density, knee extensor maximal voluntary isometric contraction strength and several functional physical fitness measures were taken before and after the intervention. Average HR during DSW (88.6 ± 7.8 bpm) was lower (P fitness measures showed greater (P health and fitness.

  5. Anatomic and Molecular Development of Corticostriatal Projection Neurons in Mice

    Science.gov (United States)

    Sohur, U. Shivraj; Padmanabhan, Hari K.; Kotchetkov, Ivan S.; Menezes, Joao R.L.; Macklis, Jeffrey D.

    2014-01-01

    Corticostriatal projection neurons (CStrPN) project from the neocortex to ipsilateral and contralateral striata to control and coordinate motor programs and movement. They are clinically important as the predominant cortical population that degenerates in Huntington's disease and corticobasal ganglionic degeneration, and their injury contributes to multiple forms of cerebral palsy. Together with their well-studied functions in motor control, these clinical connections make them a functionally, behaviorally, and clinically important population of neocortical neurons. Little is known about their development. “Intratelencephalic” CStrPN (CStrPNi), projecting to the contralateral striatum, with their axons fully within the telencephalon (intratelencephalic), are a major population of CStrPN. CStrPNi are of particular interest developmentally because they share hodological and axon guidance characteristics of both callosal projection neurons (CPN) and corticofugal projection neurons (CFuPN); CStrPNi send axons contralaterally before descending into the contralateral striatum. The relationship of CStrPNi development to that of broader CPN and CFuPN populations remains unclear; evidence suggests that CStrPNi might be evolutionary “hybrids” between CFuPN and deep layer CPN—in a sense “chimeric” with both callosal and corticofugal features. Here, we investigated the development of CStrPNi in mice—their birth, maturation, projections, and expression of molecular developmental controls over projection neuron subtype identity. PMID:23118198

  6. Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome.

    Science.gov (United States)

    Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

    2012-12-01

    Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitation and chronic descending aortic dissection immediately after Cesarean section. Regular follow-up will be needed to monitor the descending aortic dissection.

  7. Lower motor neuron findings after upper motor neuron injury: Insights from postoperative supplementary motor area syndrome

    Directory of Open Access Journals (Sweden)

    Jeffrey E Florman

    2013-03-01

    Full Text Available Hypertonia and hypereflexia are classically described responses to upper motor neuron injury. However, acute hypotonia and areflexia with motor deficit are hallmark findings after many central nervous system insults such as acute stroke and spinal shock. Historic theories to explain these contradictory findings have implicated a number of potential mechanisms mostly relying on the loss of descending corticospinal input as the underlying etiology. Unfortunately, these simple descriptions consistently fail to adequately explain the pathophysiology and connectivity leading to acute hyporeflexia and delayed hypereflexia that result from such insult. This article highlights the common observation of acute hyporeflexia after central nervous system insults and explores the underlying anatomy and physiology. Further, evidence for the underlying connectivity is presented and implicates the dominant role of supraspinal inhibitory influence originating in the supplementary motor area descending through the corticospinal tracts. Unlike traditional explanations, this theory more adequately explains the findings of postoperative supplementary motor area syndrome in which hyporeflexive motor deficit is observed acutely in the face of intact primary motor cortex connections to the spinal cord. Further, the proposed connectivity can be generalized to help explain other insults including stroke, atonic seizures, and spinal shock.

  8. Contribution of amygdala CRF neurons to chronic pain.

    Science.gov (United States)

    Andreoli, Matthew; Marketkar, Tanvi; Dimitrov, Eugene

    2017-12-01

    We investigated the role of amygdala corticotropin-releasing factor (CRF) neurons in the perturbations of descending pain inhibition caused by neuropathic pain. Forced swim increased the tail-flick response latency in uninjured mice, a phenomenon known as stress-induced analgesia (SIA) but did not change the tail-flick response latency in mice with neuropathic pain caused by sciatic nerve constriction. Neuropathic pain also increased the expression of CRF in the central amygdala (CeAmy) and ΔFosB in the dorsal horn of the spinal cord. Next, we injected the CeAmy of CRF-cre mice with cre activated AAV-DREADD (Designer Receptors Exclusively Activated by Designer Drugs) vectors. Activation of CRF neurons by DREADD/Gq did not affect the impaired SIA but inhibition of CRF neurons by DREADD/Gi restored SIA and decreased allodynia in mice with neuropathic pain. The possible downstream circuitry involved in the regulation of SIA was investigated by combined injections of retrograde cre-virus (CAV2-cre) into the locus ceruleus (LC) and cre activated AAV-diphtheria toxin (AAV-FLEX-DTX) virus into the CeAmy. The viral injections were followed by a sciatic nerve constriction ipsilateral or contralateral to the injections. Ablation of amygdala projections to the LC on the side of injury but not on the opposite side, completely restored SIA, decreased allodynia and decreased ΔFosB expression in the spinal cord in mice with neuropathic pain. The possible lateralization of SIA impairment to the side of injury was confirmed by an experiment in which unilateral inhibition of the LC decreased SIA even in uninjured mice. The current view in the field of pain research attributes the process of pain chronification to abnormal functioning of descending pain inhibition. Our results demonstrate that the continuous activity of CRF neurons brought about by persistent pain leads to impaired SIA, which is a symptom of dysregulation of descending pain inhibition. Therefore, an over

  9. Corticospinal mirror neurons

    OpenAIRE

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like p...

  10. Indigenous Arabs are descendants of the earliest split from ancient Eurasian populations.

    Science.gov (United States)

    Rodriguez-Flores, Juan L; Fakhro, Khalid; Agosto-Perez, Francisco; Ramstetter, Monica D; Arbiza, Leonardo; Vincent, Thomas L; Robay, Amal; Malek, Joel A; Suhre, Karsten; Chouchane, Lotfi; Badii, Ramin; Al-Nabet Al-Marri, Ajayeb; Abi Khalil, Charbel; Zirie, Mahmoud; Jayyousi, Amin; Salit, Jacqueline; Keinan, Alon; Clark, Andrew G; Crystal, Ronald G; Mezey, Jason G

    2016-02-01

    An open question in the history of human migration is the identity of the earliest Eurasian populations that have left contemporary descendants. The Arabian Peninsula was the initial site of the out-of-Africa migrations that occurred between 125,000 and 60,000 yr ago, leading to the hypothesis that the first Eurasian populations were established on the Peninsula and that contemporary indigenous Arabs are direct descendants of these ancient peoples. To assess this hypothesis, we sequenced the entire genomes of 104 unrelated natives of the Arabian Peninsula at high coverage, including 56 of indigenous Arab ancestry. The indigenous Arab genomes defined a cluster distinct from other ancestral groups, and these genomes showed clear hallmarks of an ancient out-of-Africa bottleneck. Similar to other Middle Eastern populations, the indigenous Arabs had higher levels of Neanderthal admixture compared to Africans but had lower levels than Europeans and Asians. These levels of Neanderthal admixture are consistent with an early divergence of Arab ancestors after the out-of-Africa bottleneck but before the major Neanderthal admixture events in Europe and other regions of Eurasia. When compared to worldwide populations sampled in the 1000 Genomes Project, although the indigenous Arabs had a signal of admixture with Europeans, they clustered in a basal, outgroup position to all 1000 Genomes non-Africans when considering pairwise similarity across the entire genome. These results place indigenous Arabs as the most distant relatives of all other contemporary non-Africans and identify these people as direct descendants of the first Eurasian populations established by the out-of-Africa migrations. © 2016 Rodriguez-Flores et al.; Published by Cold Spring Harbor Laboratory Press.

  11. Descending facilitation from the rostral ventromedial medulla maintains nerve injury-induced central sensitization.

    Science.gov (United States)

    Vera-Portocarrero, L P; Zhang, E-T; Ossipov, M H; Xie, J Y; King, T; Lai, J; Porreca, F

    2006-07-21

    Nerve injury can produce hypersensitivity to noxious and normally innocuous stimulation. Injury-induced central (i.e. spinal) sensitization is thought to arise from enhanced afferent input to the spinal cord and to be critical for expression of behavioral hypersensitivity. Descending facilitatory influences from the rostral ventromedial medulla have been suggested to also be critical for the maintenance, though not the initiation, of experimental neuropathic pain. The possibility that descending facilitation from the rostral ventromedial medulla is required for the maintenance of central sensitization was examined by determining whether ablation of mu-opioid receptor-expressing cells within the rostral ventromedial medulla prevented the enhanced expression of repetitive touch-evoked FOS within the spinal cord of animals with spinal nerve ligation injury as well as nerve injury-induced behavioral hypersensitivity. Rats received a single microinjection of vehicle, saporin, dermorphin or dermorphin-saporin into the rostral ventromedial medulla and 28 days later, underwent either sham or spinal nerve ligation procedures. Animals receiving rostral ventromedial medulla pretreatment with vehicle, dermorphin or saporin that were subjected to spinal nerve ligation demonstrated both thermal and tactile hypersensitivity, and showed significantly increased expression of touch-evoked FOS in the dorsal horn ipsilateral to nerve injury compared with sham-operated controls at days 3, 5 or 10 post-spinal nerve ligation. In contrast, nerve-injured animals pretreated with dermorphin-saporin showed enhanced behaviors and touch-evoked FOS expression in the spinal dorsal horn at day 3, but not days 5 and 10, post-spinal nerve ligation when compared with sham-operated controls. These results indicate the presence of nerve injury-induced behavioral hypersensitivity associated with nerve injury-induced central sensitization. Further, the results demonstrate the novel concept that once

  12. Allelic Lineages of the Ficolin Genes (FCNs) Are Passed from Ancestral to Descendant Primates

    DEFF Research Database (Denmark)

    Hummelshøj, Tina; Nissen, Janna; Fog, Lea Munthe

    2011-01-01

    The ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode ficolin-1, ficolin-2 and ficolin-3, res...... serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species....

  13. Allelic lineages of the ficolin genes (FCNs) are passed from ancestral to descendant primates

    DEFF Research Database (Denmark)

    Hummelshøj, Tina; Nissen, Janna; Munthe-Fog, Lea

    2011-01-01

    The ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode ficolin-1, ficolin-2 and ficolin-3, res...... serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species....

  14. Anomalous origin of the left anterior descending coronary artery from the right coronary artery

    Directory of Open Access Journals (Sweden)

    Kyriacos Papadopoulos

    2013-01-01

    Full Text Available Dual left anterior descending coronary artery (LAD originating from the left main stem and the right coronary artery (RCA (Type IV dual LAD is a very rare coronary artery anomaly. In this report, we describe a 49 year old woman presenting with unstable angina and positive for myocardial ischemia exercise tolerance test who subsequently was found to have this coronary anomaly.The diagnosis was made with coronary angiography.This anomaly has been reported to occur in 0.01 — 0.7% of patients under going cardiac catheterization. To our knowledge, only a few such cases have been published in the literature so far.

  15. Two Successful Term Pregnancies with a Large Descending Aorta Aneurysm: Case Report

    Directory of Open Access Journals (Sweden)

    Saghar Salehpour

    2008-12-01

    Full Text Available Aortic aneurysm is a rare but potentially lethal complication during pregnancy. In this article we described a 30-year-old woman with a large size descending aorta aneurysm (11 cm in length and 5.6 cm in its greatest diameter, who had two term uncomplicated pregnancies. The patient received prophylactic ß-blocker drug during her second pregnancy. Both pregnancies were terminated by caesarean section without any serious complications. Postpartum period was recovered successfully, but a noticeable increase in aneurysm’s length was detected in the period between two pregnancies.

  16. Descending aortic mechanics and atrial fibrillation: a two-dimensional speckle tracking transesophageal echocardiography study.

    Science.gov (United States)

    Teixeira, Rogério; Monteiro, Ricardo; Dinis, Paulo; Santos, Maria José; Botelho, Ana; Quintal, Nuno; Cardim, Nuno; Gonçalves, Lino

    2017-04-01

    Vascular mechanics assessed with two-dimensional speckle tracking echocardiography (2D-STE) could be used as a new imaging surrogate of vascular stiffening. The CHA 2 DS 2 -VASc score is considered accurate as an estimate of stroke risk in non-valvular AF, although many potential stroke risk factors have not been included in this scoring method. The purpose of this research is to study the feasibility of evaluating vascular mechanics at the descending aorta in non-valvular AF patients using transesophageal 2D-STE and to analyze the association between descending aortic mechanics and stroke. We prospectively recruited a group of 44 patients referred for a transesophageal echocardiogram (TEE) in the context of cardioversion for non-valvular AF. A short-axis view of the descending aorta, one to two centimeters after the aortic arch was selected for the vascular mechanics assessment with the 2D-STE methodology. The vascular mechanics parameters analyzed were circumferential aortic strain (CAS) and early circumferential aortic strain rate (CASR). A clinical assessment was performed with focus on the past stroke history and the CHA 2 DS 2 -VASc score. The mean age of our cohort was 65 ± 13 years and 75% were men; AF was known for 2.8 ± 2.5 years and it was considered paroxystic in 41% of cases. Waveforms adequate for measuring 2D-STE were present in 85% of the 264 descending aortic wall segments. The mean CAS was 3.5 ± 1.2% and the mean CASR was 0.7 ± 0.3 s -1 . The inter- and intra-observer variability for aortic mechanics was considered adequate. The median CHA 2 DS 2 VASc score was 2 (2-3). As the score increased we noted that both the CAS (r = -0.38, P = 0.01) and the CASR (r = -0.42, P mechanics assessed with transesophageal 2D-STE.

  17. Health state of children-descendants of Chernobyl NPP accident consequences cleaners

    International Nuclear Information System (INIS)

    Etsko, L.; Stratulat, P.; Vasilos, L.; Arameh, M.

    2007-01-01

    The frequency analysis of stochastic clinical effects of ionizing radiation - malignant neoplasms, endocrine abnormalities and congenital malformations was performed. For revealing dependence of prevalence marker pathology from various environmental factors, morbidity of children-descendants of the cleaners of Chernobyl NPP accident consequences was compared to those in Moldavian children (under official data) and children from ecologically adverse areas of the republic. The comparative analysis has shown that the pathology at these children does not differ from those at other children from the republic and may be consider as ecopathology. (authors)

  18. Chediak-Higashi syndrome: case report in afro-descendant individual

    Directory of Open Access Journals (Sweden)

    Judde Lacerda Andrade Carlos

    2014-06-01

    Full Text Available This is a Chediak-Higashi Syndrome (CHS case report in afro-descendant individual, male, 3 months old, born from consanguineous union. On admission he had fever for a month, unresolved pneumonia, and hepatosplenomegaly. He evolved to bacterial sepsis, septic shock, and death. CHS presents quantitative and morphological and hematological changes. Abnormal leukocyte inclusions are the pathognomonic finding of the disease; its recognition and differentiation from other leukocyte inclusions is essential for diagnosis and institution of therapy. Early diagnosis of CHS increases the life expectancy of the individual and provides appropriate therapeutic approach for patients affected by the disease.

  19. [The assimilation of Italians and their descendants in Argentine society (1880-1925)].

    Science.gov (United States)

    Nascimbene, M C

    1996-09-01

    "The impact of massive immigration in the post-1870 period produced major changes in... Argentine society. Integration of immigrant groups (Italians, Spaniards, the French and others) was nevertheless fiercely opposed by local elites. The essay is firstly concerned with size and development of immigration flows; secondly it deals with the characteristics of local reaction against the immigrants; thirdly it reveals how, in spite of the latter, the Italians' integration did take place in the Argentine middle classes. Finally, a particular case-study is presented, in connection with integration of immigrants and their descendants in the national army." (SUMMARY IN ENG AND FRE) excerpt

  20. Descending necrotising mediastinitis: two case reports and review of the literature

    Directory of Open Access Journals (Sweden)

    E. Weaver

    2010-06-01

    Full Text Available Descending necrotising mediastinitis is a rare and serious infection with a high mortality rate, which complicates pharyngeal or odontogenic infection. Early recognition and treatment are essential in order to minimise morbidity. Evaluation with computed tomography is necessary to confirm the diagnosis and facilitate surgical planning. In addition to prompt empirical antiobiotic therapy, surgical intervention is necessary in nearly all cases. Surgical drainage and debridement may be performed through cervicotomy alone, or through combined cervicotomy and thoracotomy, depending upon the extent of disease. Hyperbaric oxygen therapy may play an auxiliary role. We present two recent cases with characteristic imaging findings, and review the relevant literature.

  1. Descending necrotizing mediastinitis and mediastinal abscesses following odontogenic infection: A case report

    Directory of Open Access Journals (Sweden)

    Adnan Ekinci

    2012-06-01

    Full Text Available Descending necrotising mediastinitis (DNM is a typeof mediastinitis caused by head and neck infections,which spreads to the mediastinum via the cervical fascialplanes. This infection is a rarely reported but highly lethalinfection. Computed tomography was used to diagnosisthe disease and assess the efficacy of treatment. Delayin diagnosis and insufficient drainage of the mediastinumand deep neck infection are the main causes of mortalityin DNM. We report on a case that was treated successfully,even if with a long, protracted course. J Clin ExpInvest 2012; 3(2: 287-289

  2. A case of descending mediastinitis caused by Streptococcus pyogenes harboring genotype emm25 and sequence type 660.

    Science.gov (United States)

    Ohya, Hiroaki; Mori, Nobuaki; Hayashi, Tetsuro; Minami, Shujiro; Higuchi, Akiko; Takahashi, Takashi

    2017-06-01

    Descending mediastinitis caused by Streptococcus pyogenes (group A streptococcus, GAS) is rare among cases of invasive GAS infection. In this report, we describe a case of a cervical abscess and secondary descending mediastinitis in a previously healthy 39-year-old Japanese man. The patient presented with a 2-week history of a sore throat, and subsequently developed an abscess and descending mediastinitis. We treated the cervical abscess using ampicillin/sulbactam and drainage, and GAS was subsequently isolated in two blood cultures from the patient's admission. Microbiological analyses revealed that the isolate harbored genotype emm25 and sequence type (ST) 660. This strain was susceptible to erythromycin (minimum inhibitory concentration [MIC]: ≤0.12 μg/mL), resistant to minocycline (MIC: >4 μg/mL), and possessed the tet(M) determinant. Although we have reviewed the literature regarding the clinical and microbiological characteristics of descending mediastinitis cause by GAS, little is known regarding epidemiological and clinical characteristics of emm25/ST660 GAS. Furthermore, to best of our knowledge, this is the first reported case of descending mediastinitis caused by emm25/ST660 GAS. Therefore, physicians should be aware of case with a cervical abscess and secondary descending mediastinitis caused by GAS infection, even if the patient is immunocompetent. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  3. Kappe neurons, a novel population of olfactory sensory neurons

    OpenAIRE

    Ahuja, Gaurav; Nia, Shahrzad Bozorg; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I.

    2014-01-01

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons ar...

  4. Corticospinal mirror neurons.

    Science.gov (United States)

    Kraskov, A; Philipp, R; Waldert, S; Vigneswaran, G; Quallo, M M; Lemon, R N

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons' discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited 'classical' mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation ('suppression mirror-neurons'). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others.

  5. Characterization of the melanin-concentrating hormone neurons activated during paradoxical sleep hypersomnia in rats.

    Science.gov (United States)

    Hanriot, Lucie; Camargo, Nutabi; Courau, Anne Claire; Leger, Lucienne; Luppi, Pierre Hervé; Peyron, Christelle

    2007-11-10

    Although the main nodes of the neuronal network that regulate paradoxical sleep (PS), also called rapid eye movement sleep, have been identified in rodents, it still needs to be more thoroughly described. We have recently shown that 58% of a hypothalamic neuronal population, the melanin-concentrating hormone (MCH) neurons, are activated after a PS hypersomnia and that MCH, when injected intracerebroventricularly, induces a dose-dependent increase in PS. This suggests that MCH plays a role in PS regulation. Two subpopulations of MCH neurons have been distinguished neurochemically, one that coexpresses cocaine and amphetamine-regulated transcript (CART) and sends ascending projections to the septum and the hippocampus, the other, the non-CART MCH neurons, send descending projections to the lower brainstem and the spinal cord. In order to better characterize the PS-activated MCH neurons it is interesting to determine whether they belong to the first, the second, or both subgroups. We therefore undertook an MCH, CART, and Fos triple immunolabeling study in PS hypersomniac rats. We showed that the MCH neurons activated during PS are part of both subpopulations since we found CART and non-CART MCH-activated neurons. Based on these results and the literature, we propose that MCH could be involved in memory processes and in the inhibition of muscle tone during PS. 2007 Wiley-Liss, Inc

  6. NEURON and Python.

    Science.gov (United States)

    Hines, Michael L; Davison, Andrew P; Muller, Eilif

    2009-01-01

    The NEURON simulation program now allows Python to be used, alone or in combination with NEURON's traditional Hoc interpreter. Adding Python to NEURON has the immediate benefit of making available a very extensive suite of analysis tools written for engineering and science. It also catalyzes NEURON software development by offering users a modern programming tool that is recognized for its flexibility and power to create and maintain complex programs. At the same time, nothing is lost because all existing models written in Hoc, including graphical user interface tools, continue to work without change and are also available within the Python context. An example of the benefits of Python availability is the use of the xml module in implementing NEURON's Import3D and CellBuild tools to read MorphML and NeuroML model specifications.

  7. Pedicled Descending Branch Latissimus Dorsi Mini-flap for Repairing Partial Mastectomy Defect: A New Technique

    Directory of Open Access Journals (Sweden)

    Ruizhao Cai, M.D.

    2018-03-01

    Full Text Available Summary:. Volume loss is 1 of the major factors influencing cosmetic outcomes of breast after partial mastectomy (PM, especially for smaller breasts, and therefore, volume replacement is critical for optimizing the final aesthetic outcome. We present a novel technique of raising a pedicled descending branch latissimus dorsi (LD mini-flap for reconstruction of PM defects via an axillary incision. After PM, the LD mini-flap is harvested through the existing axillary incision of the axillary dissection or the sentinel lymph node biopsy. The descending branches of thoracodorsal vessels and nerve are carefully identified and isolated. The transverse branches are protected to maintain muscle innervation and function. The LD muscle is then undermined posteriorly and inferiorly to create a submuscular pocket and a subcutaneous pocket between LD muscle and superficial fascia. Once the submuscular plane is created, the muscle is divided along the muscle fibers from the deep surface including a layer of fat above the muscle. Finally, the LD mini-flap is transferred to the breast defect. Given the limited length and mobility of the LD mini-flap, this approach is best utilized for lateral breast defects. However, for medial defects, the lateral breast tissue is rearranged to reconstruct the medial breast defect, and an LD mini-flap is then used to reconstruct the lateral breast donor site. This technique can therefore be employed to reconstruct all quadrants of the breast and can provide aesthetic outcomes without scars on the back, with minimal dysfunction of LD muscle.

  8. Math modeling for helicopter simulation of low speed, low altitude and steeply descending flight

    Science.gov (United States)

    Sheridan, P. F.; Robinson, C.; Shaw, J.; White, F.

    1982-01-01

    A math model was formulated to represent some of the aerodynamic effects of low speed, low altitude, and steeply descending flight. The formulation is intended to be consistent with the single rotor real time simulation model at NASA Ames Research Center. The effect of low speed, low altitude flight on main rotor downwash was obtained by assuming a uniform plus first harmonic inflow model and then by using wind tunnel data in the form of hub loads to solve for the inflow coefficients. The result was a set of tables for steady and first harmonic inflow coefficients as functions of ground proximity, angle of attack, and airspeed. The aerodynamics associated with steep descending flight in the vortex ring state were modeled by replacing the steady induced downwash derived from momentum theory with an experimentally derived value and by including a thrust fluctuations effect due to vortex shedding. Tables of the induced downwash and the magnitude of the thrust fluctuations were created as functions of angle of attack and airspeed.

  9. Measurement of hemodynamic changes with the axial flow blood pump installed in descending aorta.

    Science.gov (United States)

    Okamoto, Eiji; Yano, Tetsuya; Miura, Hidekazu; Shiraishi, Yasuyuki; Yambe, Tomoyuki; Mitamura, Yoshinori

    2017-12-01

    We have developed various axial flow blood pumps to realize the concept of the Valvo pump, and we have studied hemodynamic changes under cardiac assistance using an axial flow blood pump in series with the natural heart. In this study, we measured hemodynamic changes of not only systemic circulation but also cerebral circulation and coronary circulation under cardiac support using our latest axial flow blood pump placed in the descending aorta in an acute animal experiment. The axial flow blood pump was installed at the thoracic descending aorta through a left thoracotomy of a goat (43.8 kg, female). When the pump was on, the aortic pressure and aortic flow downstream of the pump increased with preservation of pulsatilities. The pressure drop upstream of the pump caused reduction of afterload pressure, and it may lead to reduction of left ventricular wall stress. However, cerebral blood flow and coronary blood flow were decreased when the pump was on. The axial flow blood pump enables more effective blood perfusion into systemic circulation, but it has the potential risk of blood perfusion disturbance into cerebral circulation and coronary circulation. The results indicate that the position before the coronary ostia might be suitable for implantation of the axial flow blood pump in series with the natural heart to avoid blood perfusion disturbances.

  10. Quantification of progression and regression of descending thoracic aortic wall thickness by enhanced computed tomography

    International Nuclear Information System (INIS)

    Yokoyama, Kenichi; Takasu, Junichiro; Yamamoto, Rie; Taguchi, Rie; Itani, Yasutaka; Ito, Yuichi; Watanabe, Shigeru; Masuda, Yoshiaki

    2001-01-01

    The purpose of this study is to verify the usefulness of the quantification of aortic wall involvement by enhanced computed tomography (CT). One-hundred thirteen Japanese patients underwent two enhanced CT of the descending thoracic aorta at intervals. We sliced the descending thoracic aorta continuously from the level of the tracheal bifurcation with 1 cm intervals, and we defined aortic wall volume (AWV) (cm 3 ) as the sum of a 7-slice area of aortic wall involving calcification. The average of AWV increased from 7.95±2.92 cm 3 to 8.70±2.98 cm 3 . The developmental rate of AWV (ΔAWV) was 0.270±0.281 cm 3 /year. ΔAWV did not have a significant correlation with any risk factor at the baseline. ΔAWV had significant correlation with total cholesterol, (LDL-C) low-density lipoprotein cholesterol and LDL-C/(HDL-C) high-density lipoprotein cholesterol ratio at the follow-up, and by multivariate analysis with only the LDL-C/HDL-C ratio. ΔAWV was not correlated with the intake status of hypoglycemic, antihypertensive or lipid-lowering drugs. The cut-off level of total cholesterol with the most significant odds ratio for progression of aortic wall was 190 mg/dl, and that of LDL-C was 130 mg/dl. This method proved to be useful for the non-invasive assessment of aortic wall thickness. (author)

  11. Neuronal-glial trafficking

    International Nuclear Information System (INIS)

    Bachelard, H.S.

    2001-01-01

    Full text: The name 'glia' originates from the Greek word for glue, because astro glia (or astrocytes) were thought only to provide an anatomical framework for the electrically-excitable neurones. However, awareness that astrocytes perform vital roles in protecting the neurones, which they surround, emerged from evidence that they act as neuroprotective K + -sinks, and that they remove potentially toxic extracellular glutamate from the vicinity of the neurones. The astrocytes convert the glutamate to non-toxic glutamine which is returned to the neurones and used to replenish transmitter glutamate. This 'glutamate-glutamine cycle' (established in the 1960s by Berl and his colleagues) also contributes to protecting the neurones against a build-up of toxic ammonia. Glial cells also supply the neurones with components for free-radical scavenging glutathione. Recent studies have revealed that glial cells play a more positive interactive role in furnishing the neurones with fuels. Studies using radioactive 14 C, 13 C-MRS and 15 N-GCMS have revealed that glia produce alanine, lactate and proline for consumption by neurones, with increased formation of neurotransmitter glutamate. On neuronal activation the release of NH 4 + and glutamate from the neurones stimulates glucose uptake and glycolysis in the glia to produce more alanine, which can be regarded as an 'alanine-glutamate cycle' Use of 14 C-labelled precursors provided early evidence that neurotransmitter GABA may be partly derived from glial glutamine, and this has been confirmed recently in vivo by MRS isotopomer analysis of the GABA and glutamine labelled from 13 C-acetate. Relative rates of intermediary metabolism in glia and neurones can be calculated using a combination of [1- 13 C] glucose and [1,2- 13 C] acetate. When glutamate is released by neurones there is a net neuronal loss of TCA intermediates which have to be replenished. Part of this is derived from carboxylation of pyruvate, (pyruvate carboxylase

  12. Anatomical distribution of estrogen target neurons in turtle brain

    International Nuclear Information System (INIS)

    Kim, Y.S.; Stumpf, W.E.; Sar, M.

    1981-01-01

    Autoradiographic studies with [ 3 H]estradiol-17β in red-eared turtle (Pseudemys scripta elegans) show concentration and retention of radioactivity in nuclei of neurons in certain regions. Accumulations of estrogen target neurons exist in the periventricular brain with relationships to ventral extensions of the forebrain ventricles, including parolfactory, amygdaloid, septal, preoptic, hypothalamic and thalamic areas, as well as the dorsal ventricular ridge, the piriform cortex, and midbrain-pontine periaqueductal structures. The general anatomical pattern of distribution of estrogen target neurons corresponds to those observed not only in another reptile (Anolis carolinensis), but also in birds and mammals, as well as in teleosts and cyclostomes. In Pseudemys, which appears to display an intermediate degree of phylogenetic differentiation, the amygdaloid-septal-preoptic groups of estrogen target neurons constitute a continuum. In phylogenetic ascendency, e.g. in mammals, these cell populations are increasingly separated and distinct, while in phylogenetic descendency, e.g. in teleosts and cyclostomes, an amygdaloid group appears to be absent or contained within the septal-preoptic target cell population. (Auth.)

  13. Single neuron computation

    CERN Document Server

    McKenna, Thomas M; Zornetzer, Steven F

    1992-01-01

    This book contains twenty-two original contributions that provide a comprehensive overview of computational approaches to understanding a single neuron structure. The focus on cellular-level processes is twofold. From a computational neuroscience perspective, a thorough understanding of the information processing performed by single neurons leads to an understanding of circuit- and systems-level activity. From the standpoint of artificial neural networks (ANNs), a single real neuron is as complex an operational unit as an entire ANN, and formalizing the complex computations performed by real n

  14. Mesmerising mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2010-06-01

    Mirror neurons have been hailed as the key to understanding social cognition. I argue that three currents of thought-relating to evolution, atomism and telepathy-have magnified the perceived importance of mirror neurons. When they are understood to be a product of associative learning, rather than an adaptation for social cognition, mirror neurons are no longer mesmerising, but they continue to raise important questions about both the psychology of science and the neural bases of social cognition. Copyright 2010 Elsevier Inc. All rights reserved.

  15. In the Piriform Cortex, the Primary Impetus for Information Encoding through Synaptic Plasticity Is Provided by Descending Rather than Ascending Olfactory Inputs.

    Science.gov (United States)

    Strauch, Christina; Manahan-Vaughan, Denise

    2018-02-01

    Information encoding by means of persistent changes in synaptic strength supports long-term information storage and memory in structures such as the hippocampus. In the piriform cortex (PC), that engages in the processing of associative memory, only short-term synaptic plasticity has been described to date, both in vitro and in anesthetized rodents in vivo. Whether the PC maintains changes in synaptic strength for longer periods of time is unknown: Such a property would indicate that it can serve as a repository for long-term memories. Here, we report that in freely behaving animals, frequency-dependent synaptic plasticity does not occur in the anterior PC (aPC) following patterned stimulation of the olfactory bulb (OB). Naris closure changed action potential properties of aPC neurons and enabled expression of long-term potentiation (LTP) by OB stimulation, indicating that an intrinsic ability to express synaptic plasticity is present. Odor discrimination and categorization in the aPC is supported by descending inputs from the orbitofrontal cortex (OFC). Here, OFC stimulation resulted in LTP (>4 h), suggesting that this structure plays an important role in promoting information encoding through synaptic plasticity in the aPC. These persistent changes in synaptic strength are likely to comprise a means through which long-term memories are encoded and/or retained in the PC. © The Author 2017. Published by Oxford University Press.

  16. Inequality in self-rated health among immigrants, their descendants and ethnic Danes: examining the role of socioeconomic position.

    Science.gov (United States)

    Dinesen, Cecilie; Nielsen, Signe Smith; Mortensen, Laust Hvas; Krasnik, Allan

    2011-10-01

    We investigated inequalities in self-rated health between immigrants, their descendants, and ethnic Danes and explored mediation by socioeconomic position and interactions between country of origin and socioeconomic position. Cross-sectional survey data on self-rated health from 4,985 individuals aged 18-66 years including immigrants from seven non-Western countries, their descendants, and ethnic Danes was linked to registry-based data on education, employment status, and income as indicators of socioeconomic position. Using multiple logistic regression analysis, we estimated the association between country of origin and self-rated health. Immigrants reported poorer health compared with ethnic Danes [age-adjusted odds ratio (OR) = 2.0-7.3 for men; 2.1-10.5 for women, dependent on country of origin] as well as their descendants (OR = 1.6-3.8 for men; 1.5-2.0 for women). Adjustment for socioeconomic position attenuated this association. Stratified analysis indicated that the effect of socioeconomic position on self-rated health varied across the groups. Policies addressing inequalities in health between immigrants, their descendants, and ethnic Danes should target underlying socioeconomic inequalities. Further research of the effects of socioeconomic position on health among immigrants and descendants is needed.

  17. Pregnant Students Of Secondary Schools As Descendants Of Unwed Mothers Some Lessons To Learn

    Directory of Open Access Journals (Sweden)

    Rosenda M. Wamelda

    2015-08-01

    Full Text Available This phenomenological study was designed to determine the experiences of pregnant secondary school students aged 12-19 students who were descendants of unwed mothers. In-depth-interview and focus group discussion were applied with 14 pregnant students who were utilized in selecting the participants of the study. The participants revealed that their experiences were on humiliation and disdain remorse fear and insecurity escape and remediation support and love financial constraints and acquiescence. Their coping mechanisms were being positive about the situation having the aid and support of the family faith and hope to the divine God and the wisdom of the family. Importantly the teenage mothers valued the lessons learned from the experience the values of resilience and elasticity resolution and repentance for what they have done and hopes and dreams for the future.

  18. Descending Necrotizing Mediastinitis Treated with Tooth Extractions following Mediastinal and Cervical Drainage

    Directory of Open Access Journals (Sweden)

    Minoru Fukuchi

    2015-10-01

    Full Text Available Descending necrotizing mediastinitis (DNM is a rare condition in which oropharyngeal infection spreads to the mediastinum via the cervical fascia. Delayed diagnosis and surgery result in a high mortality rate among patients with DNM. We present a case of DNM resulting from odontogenic infection treated successfully with tooth extraction following mediastinal and cervical drainage. A 43-year-old, previously healthy Japanese man was admitted to our hospital for treatment of acute mediastinitis. Computed tomography revealed gas collection around the mid-thoracic esophagus and bilateral pleural effusion. We performed mediastinal drainage via right thoracotomy. Cervicotomy was performed on postoperative day 14 to drain a residual cervical abscess. The patient required the extraction of ten teeth over three procedures to address primary odontogenic infection before his fever resolved on postoperative day 40. Prompt diagnosis, aggressive drainage and removal of the source of infection can improve survival among patients with this life-threatening disease.

  19. Scuba diving, acute left anterior descending artery occlusion and normal ECG

    Science.gov (United States)

    Doll, Sébastien Xavier; Rigamonti, Fabio; Roffi, Marco; Noble, Stéphane

    2013-01-01

    We report the case of an acute proximal occlusion of the left anterior descending coronary (LAD) artery following a scuba diving decompression accident and associated with normal ECG. Following uneventful thromboaspiration and coronary stenting, the patient was discharged on day  4 with secondary preventative therapies. A transthoracic echocardiography performed at this point showed a complete recovery compared with an initial localised akinesia involving the anterior and apical portion of the left ventricle upon admission. This case highlights that significant acute coronary lesions involving the LAD can occur without any ECG anomaly. The presence of acute and persistent angina associated with troponin elevation should prompt physicians to consider coronary angiography without delay, independently of the ECG results. PMID:23376677

  20. Fertility among descendants of immigrants in Belgium: The role of the partner

    Directory of Open Access Journals (Sweden)

    Lisa Van Landschoot

    2017-06-01

    Full Text Available Background: Research on the fertility behavior of descendants of immigrants has focused on female characteristics and has largely neglected those of the male partner. One key aspect is whether the partner is of same (endogamous or of different (exogamous ethnic origin. Moreover, the male partner may be born in the same country as the female partner, or he may have migrated to that country later in the life course. Consequently, both his ethnic origin and migration history may affect the fertility behavior of second-generation women. Objective: This study analyzes to what extent second and higher order births of second-generation women of Southern European, Turkish, or Moroccan origin in Belgium differ by the ethnic origin and migration history of the male partner. Methods: We apply event history methods using the 2001 Belgian Census, linked with the 2006 Belgian National Population Register. Results: Women of Turkish and Moroccan origin in an endogamous union experience higher second and subsequent birth rates than their counterparts in an exogamous union. However, no variation is found within the endogamous unions: Whether or not the endogamous partner has been born in the country of origin does not seem to affect second and higher order birth rates. For women of Southern European origin, second and higher order birth rates do not differ by origin and generation of their partner. Contribution: This study extends the literature on the fertility behavior of the descendants of immigrants by demonstrating the importance of male partner characteristics in explaining the transition to a second or a higher order birth.

  1. Nutritional profile in children under five years of Afro-descendant communities in Paraguay

    Directory of Open Access Journals (Sweden)

    Susana Sánchez-Bernal

    2015-12-01

    Full Text Available Background: In Paraguay, little is known about the Afro-descendant population. It is important to know about their nutritional status, mainly in childhood, to guide appropriate action. Objective: To determine the nutritional profile of children under five years from the African descendants’ communities in Paraguay and its associated factors. Material and methods: A cross-sectional and observational design with analytical component was developed. It involved healthy male and female children under five years old, with at least one African descendant as immediate family. Dietary habits and nutritional status (WHO criteria were assessed. WHO Anthro and SPSS 16.0 software were used. Results: 150 children were included. The median of age was 26.9 months (1.2-59.9 m, and 50.7% were males. The median maternal age was 28.3 years (16-49 years. Children with Exclusive Breast Feeding (EBF, n=119 had a mean duration of 3.5±1.8 months (1-7m. 26.9% were exclusively breastfed during six months. The starting of complementary feeding was on average 5.2 months. The underweight prevalence (UW, zP/E 0.05. Children with UW had a lower average of age of onset of complementary feeding (1.7 vs 4.9 months, p˂0.0001 compare with their pairs without malnutrition. Conclusion: Chronic malnutrition was the most prevalent chronic disease affecting over 1 in 10 children. Early initiation of complementary feeding could be a risk factor for malnutrition.

  2. Numerical simulation of left ventricular assist device implantations: comparing the ascending and the descending aorta cannulations.

    Science.gov (United States)

    Bonnemain, Jean; Malossi, A Cristiano I; Lesinigo, Matteo; Deparis, Simone; Quarteroni, Alfio; von Segesser, Ludwig K

    2013-10-01

    In this work we present numerical simulations of continuous flow left ventricle assist device implantation with the aim of comparing difference in flow rates and pressure patterns depending on the location of the anastomosis and the rotational speed of the device. Despite the fact that the descending aorta anastomosis approach is less invasive, since it does not require a sternotomy and a cardiopulmonary bypass, its benefits are still controversial. Moreover, the device rotational speed should be correctly chosen to avoid anomalous flow rates and pressure distribution in specific location of the cardiovascular tree. With the aim of assessing the differences between these two approaches and device rotational speed in terms of flow rate and pressure waveforms, we set up numerical simulations of network of one-dimensional models where we account for the presence of an outflow cannula anastomosed to different locations of the aorta. Then, we use the resulting network to compare the results of the two different cannulations for several stages of heart failure and different rotational speed of the device. The inflow boundary data for the heart and the cannulas are obtained from a lumped parameters model of the entire circulatory system with an assist device, which is validated with clinical data. The results show that ascending and descending aorta cannulations lead to similar waveforms and mean flow rate in all the considered cases. Moreover, regardless of the anastomosis region, the rotational speed of the device has an important impact on wave profiles; this effect is more pronounced at high RPM. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  3. Corticospinal mirror neurons

    Science.gov (United States)

    Kraskov, A.; Philipp, R.; Waldert, S.; Vigneswaran, G.; Quallo, M. M.; Lemon, R. N.

    2014-01-01

    Here, we report the properties of neurons with mirror-like characteristics that were identified as pyramidal tract neurons (PTNs) and recorded in the ventral premotor cortex (area F5) and primary motor cortex (M1) of three macaque monkeys. We analysed the neurons’ discharge while the monkeys performed active grasp of either food or an object, and also while they observed an experimenter carrying out a similar range of grasps. A considerable proportion of tested PTNs showed clear mirror-like properties (52% F5 and 58% M1). Some PTNs exhibited ‘classical’ mirror neuron properties, increasing activity for both execution and observation, while others decreased their discharge during observation (‘suppression mirror-neurons’). These experiments not only demonstrate the existence of PTNs as mirror neurons in M1, but also reveal some interesting differences between M1 and F5 mirror PTNs. Although observation-related changes in the discharge of PTNs must reach the spinal cord and will include some direct projections to motoneurons supplying grasping muscles, there was no EMG activity in these muscles during action observation. We suggest that the mirror neuron system is involved in the withholding of unwanted movement during action observation. Mirror neurons are differentially recruited in the behaviour that switches rapidly between making your own movements and observing those of others. PMID:24778371

  4. Fear conditioning suppresses large-conductance calcium-activated potassium channels in lateral amygdala neurons.

    Science.gov (United States)

    Sun, P; Zhang, Q; Zhang, Y; Wang, F; Wang, L; Yamamoto, R; Sugai, T; Kato, N

    2015-01-01

    It was previously shown that depression-like behavior is accompanied with suppression of the large-conductance calcium activated potassium (BK) channel in cingulate cortex pyramidal cells. To test whether BK channels are also involved in fear conditioning, we studied neuronal properties of amygdala principal cells in fear conditioned mice. After behavior, we made brain slices containing the amygdala, the structure critically relevant to fear memory. The resting membrane potential in lateral amygdala (LA) neurons obtained from fear conditioned mice (FC group) was more depolarized than in neurons from naïve controls. The frequencies of spikes evoked by current injections were higher in neurons from FC mice, demonstrating that excitability of LA neurons was elevated by fear conditioning. The depolarization in neurons from FC mice was shown to depend on BK channels by using the BK channel blocker charybdotoxin. Suppression of BK channels in LA neurons from the FC group was further confirmed on the basis of the spike width, since BK channels affect the descending phase of spikes. Spikes were broader in the FC group than those in the naïve control in a manner dependent on BK channels. Consistently, quantitative real-time PCR revealed a decreased expression of BK channel mRNA. The present findings suggest that emotional disorder manifested in the forms of fear conditioning is accompanied with BK channel suppression in the amygdala, the brain structure critical to this emotional disorder. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. Infections of the neck leading to descending necrotizing mediastinitis: Role of multi-detector row computed tomography

    International Nuclear Information System (INIS)

    Pinto, Antonio; Scaglione, Mariano; Scuderi, Maria Giuseppina; Tortora, Giovanni; Daniele, Stefania; Romano, Luigia

    2008-01-01

    Descending necrotizing mediastinitis is an acute, polymicrobial infection of the mediastinum, originating from odontogenic, oropharyngeal and cervical infections. Anatomical continuity of the fascial spaces between the neck and the mediastinum leads to an occasional mediastinal extension of deep neck infection as a serious sequela. An understanding of the anatomy of the deep spaces of the neck and familiarity with the imaging findings in descending necrotizing mediastinitis may allow rapid diagnosis and treatment of this rare and life-threatening complication of deep neck space infection. In this article, we discuss the current role of radiology in diagnosing descending necrotizing mediastinitis, in determining the level of infection and the pathways of spread of infections from the neck to the mediastinum and in planning a successful treatment

  6. Infections of the neck leading to descending necrotizing mediastinitis: Role of multi-detector row computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Antonio [Department of Diagnostic Imaging, A. Cardarelli Hospital, 80131 Naples (Italy)], E-mail: antopin1968@libero.it; Scaglione, Mariano; Scuderi, Maria Giuseppina; Tortora, Giovanni; Daniele, Stefania; Romano, Luigia [Department of Diagnostic Imaging, A. Cardarelli Hospital, 80131 Naples (Italy)

    2008-03-15

    Descending necrotizing mediastinitis is an acute, polymicrobial infection of the mediastinum, originating from odontogenic, oropharyngeal and cervical infections. Anatomical continuity of the fascial spaces between the neck and the mediastinum leads to an occasional mediastinal extension of deep neck infection as a serious sequela. An understanding of the anatomy of the deep spaces of the neck and familiarity with the imaging findings in descending necrotizing mediastinitis may allow rapid diagnosis and treatment of this rare and life-threatening complication of deep neck space infection. In this article, we discuss the current role of radiology in diagnosing descending necrotizing mediastinitis, in determining the level of infection and the pathways of spread of infections from the neck to the mediastinum and in planning a successful treatment.

  7. Semi-automated segmentation of the sigmoid and descending colon for radiotherapy planning using the fast marching method

    International Nuclear Information System (INIS)

    Losnegaard, Are; Hodneland, Erlend; Lundervold, Arvid; Hysing, Liv Bolstad; Muren, Ludvig Paul

    2010-01-01

    A fast and accurate segmentation of organs at risk, such as the healthy colon, would be of benefit for planning of radiotherapy, in particular in an adaptive scenario. For the treatment of pelvic tumours, a great challenge is the segmentation of the most adjacent and sensitive parts of the gastrointestinal tract, the sigmoid and descending colon. We propose a semi-automated method to segment these bowel parts using the fast marching (FM) method. Standard 3D computed tomography (CT) image data obtained from routine radiotherapy planning were used. Our pre-processing steps distinguish the intestine, muscles and air from connective tissue. The core part of our method separates the sigmoid and descending colon from the muscles and other segments of the intestine. This is done by utilizing the ability of the FM method to compute a specified minimal energy functional integrated along a path, and thereby extracting the colon centre line between user-defined control points in the sigmoid and descending colon. Further, we reconstruct the tube-shaped geometry of the sigmoid and descending colon by fitting ellipsoids to points on the path and by adding adjacent voxels that are likely voxels belonging to these bowel parts. Our results were compared to manually outlined sigmoid and descending colon, and evaluated using the Dice coefficient (DC). Tests on 11 patients gave an average DC of 0.83 (±0.07) with little user interaction. We conclude that the proposed method makes it possible to fast and accurately segment the sigmoid and descending colon from routine CT image data.

  8. General trigeminospinal central sensitization and impaired descending pain inhibitory controls contribute to migraine progression.

    Science.gov (United States)

    Boyer, Nelly; Dallel, Radhouane; Artola, Alain; Monconduit, Lénaïc

    2014-07-01

    Migraine is a chronic disease with episodic manifestations. In a subgroup, attack frequency increases over time, leading to chronic migraine. One of the most important risk factors for migraine progression is frequency of headache attacks at baseline. Unfortunately, the actual effects of repeated activation of dural nociceptors are poorly known. We investigated the behavioral, anatomical, and electrophysiological changes induced by repeated low- and high-intensity stimulation of meningeal nociceptor by injecting an inflammatory soup in rats. Single high-intensity, but not low-intensity, stimulation produces a reversible cephalic allodynia. Upon repetition, however, low-intensity stimulation, too, induces a reversible cephalic allodynia, and high-intensity, reversible cephalic and extracephalic allodynia. Moreover, cephalic allodynia becomes, in part, persistent upon repeated high-intensity stimulation. Fos expression reveals that a single high-intensity stimulation already leads to widespread, trigeminal, and spinal central sensitization, and that such general central sensitization potentiates upon repetition. Trigeminovascular nociceptive neurons become persistently sensitized and their diffuse noxious inhibitory controls (DNIC) concomitantly impaired. Thus, compared with single stimulation, repeated dural nociceptor activation specifically leads to: 1) a gradual worsening of cutaneous hypersensitivity and general neuronal hyperexcitability and 2) spreading of cutaneous hypersensitivity superimposed on 3) persistent cephalic cutaneous hypersensitivity and trigeminal central sensitization. Such repetition-induced development of central sensitization and its consequence, cutaneous allodynia, may arise from both the general neuronal hyperexcitability that results from DNIC impairment and hyperexcitability that likely develops in trigeminal nociceptive neurons in response to their repetitive activation. These neuronal changes may in turn elevate the risk for

  9. Neuronal avalanches and learning

    Energy Technology Data Exchange (ETDEWEB)

    Arcangelis, Lucilla de, E-mail: dearcangelis@na.infn.it [Department of Information Engineering and CNISM, Second University of Naples, 81031 Aversa (Italy)

    2011-05-01

    Networks of living neurons represent one of the most fascinating systems of biology. If the physical and chemical mechanisms at the basis of the functioning of a single neuron are quite well understood, the collective behaviour of a system of many neurons is an extremely intriguing subject. Crucial ingredient of this complex behaviour is the plasticity property of the network, namely the capacity to adapt and evolve depending on the level of activity. This plastic ability is believed, nowadays, to be at the basis of learning and memory in real brains. Spontaneous neuronal activity has recently shown features in common to other complex systems. Experimental data have, in fact, shown that electrical information propagates in a cortex slice via an avalanche mode. These avalanches are characterized by a power law distribution for the size and duration, features found in other problems in the context of the physics of complex systems and successful models have been developed to describe their behaviour. In this contribution we discuss a statistical mechanical model for the complex activity in a neuronal network. The model implements the main physiological properties of living neurons and is able to reproduce recent experimental results. Then, we discuss the learning abilities of this neuronal network. Learning occurs via plastic adaptation of synaptic strengths by a non-uniform negative feedback mechanism. The system is able to learn all the tested rules, in particular the exclusive OR (XOR) and a random rule with three inputs. The learning dynamics exhibits universal features as function of the strength of plastic adaptation. Any rule could be learned provided that the plastic adaptation is sufficiently slow.

  10. Percutaneous coronary intervention with ABSORB biodegradable vascular scaffold in patients with left anterior descending artery disease

    Directory of Open Access Journals (Sweden)

    К. М. Ваккосов

    2017-04-01

    Full Text Available Aim. The article evaluates 30-day results of percutaneous coronary intervention (PCI with ABSORB biodegradable vascular scaffold (BVS implanted in the case of stenosis of the left anterior descending (LAD coronary artery in patients with stable angina.Methods. 64 patients with significant (≥ 70% LAD disease were included in the study. At 30 days, scaffold thrombosis and major adverse cardiovascular events (all-cause mortality, myocardial infarction, stroke, target vessel revascularization were evaluated. The indicator of successful percutaneous coronary intervention (residual stenosis ≤20% in the presence of counterpulsation corresponding to TIMI 3rd Grade and in the absence of significant in-patient clinical complications and successful intervention assessed by clinical criteria (successful percutaneous coronary intervention alongside with a decrease in objective and subjective symptoms of myocardial ischemia, or their complete disappearance were also analyzed. Results. Mean age of patients was 61.6±8.5 years, with males accounting for 64%; 33% had earlier MI, 14% – diabetes mellitus. Mean left ventricular ejection fraction was 61.3±6.8%. Left anterior descending artery disease was presented in 89% of patients with SYNTAX Score 6.6±2.2. Mean number of implanted stents was 1.2±0.4, with mean length of the stented segment equal to18.7±1.8 mm and mean diameter 3.2±0.3 mm. At 30-day follow-up, the success of intervention assessed by clinical criteria amounted to 96.9% (n=62; that of myocardial infarction 3.1% (n=2; stent thrombosis 1.56% (n=1; repeated revascularization 1.56% (n=1; major adverse cardiovascular events (MACE 3.1%.Conclusion. The implantation of everolimus-eluting BVS for LAD stenosis demonstrates satisfactory results at 30-day follow-up.Received 16 January 2017. Accepted 21 March 2017.Financing: The study did not have sponsorship.Conflict of interest: The authors declare no conflict of interest.

  11. Cervical necrotizing fasciitis with descending mediastinitis: literature review and case report.

    Science.gov (United States)

    Sarna, Thomas; Sengupta, Trina; Miloro, Michael; Kolokythas, Antonia

    2012-06-01

    Cervical necrotizing fasciitis (CNF) can develop from odontogenic infections that spread to the deep fascial planes of the neck. This polymicrobial infection is rapidly progressive, destructive, and often fatal. Prompt diagnosis, recognition of acuity, aggressive, repeated surgical treatment, and medical management contribute to improved survival. Nevertheless, the progression of the disease to descending mediastinitis and septic shock leads to a poor prognosis and decreased survival. A comprehensive review of the current data regarding CNF was conducted using MEDLINE, PubMed, Scopus, and Google Scholar. The diagnostic elements, comorbid conditions, treatment modalities, complications, and survival rates were analyzed. CNF has a reported mortality rate of 7% to 20%, depending on the extent of neck involvement. When the disease progresses into the thorax, such as in the subset of patients with CNF complicated by descending necrotizing mediastinitis (DNM) of odontogenic origin, the mortality rate increases to 41%. This is greater than the reported mortality rate of 22% for DNM in cardiothoracic studies. When DNM is present, the risk of developing septic shock appears to be much greater, 22% versus 7%. In the presence of CNF, DNM, and sepsis, the mortality rate increases to 64%. Those who survive CNF complicated by DNM and sepsis have truly beaten the odds. CNF is an uncommon, but potentially fatal, condition that oral and maxillofacial surgeons might be called on to manage emergently. Treatment includes surgery and medical intensive care. Surgeons offer the best odds of patient survival by following these basic principles: airway security, early aggressive incision and drainage plus debridement with thoracotomy, as needed, close surveillance with computed tomography, and a low threshold for retreatment. In immunocompromised patients, even greater vigilance is required. Antibiotic therapy should be adjusted as cultures and sensitivities become available. Advances in

  12. Kappe neurons, a novel population of olfactory sensory neurons.

    Science.gov (United States)

    Ahuja, Gaurav; Bozorg Nia, Shahrzad; Zapilko, Veronika; Shiriagin, Vladimir; Kowatschew, Daniel; Oka, Yuichiro; Korsching, Sigrun I

    2014-02-10

    Perception of olfactory stimuli is mediated by distinct populations of olfactory sensory neurons, each with a characteristic set of morphological as well as functional parameters. Beyond two large populations of ciliated and microvillous neurons, a third population, crypt neurons, has been identified in teleost and cartilaginous fishes. We report here a novel, fourth olfactory sensory neuron population in zebrafish, which we named kappe neurons for their characteristic shape. Kappe neurons are identified by their Go-like immunoreactivity, and show a distinct spatial distribution within the olfactory epithelium, similar to, but significantly different from that of crypt neurons. Furthermore, kappe neurons project to a single identified target glomerulus within the olfactory bulb, mdg5 of the mediodorsal cluster, whereas crypt neurons are known to project exclusively to the mdg2 glomerulus. Kappe neurons are negative for established markers of ciliated, microvillous and crypt neurons, but appear to have microvilli. Kappe neurons constitute the fourth type of olfactory sensory neurons reported in teleost fishes and their existence suggests that encoding of olfactory stimuli may require a higher complexity than hitherto assumed already in the peripheral olfactory system.

  13. Stochastic neuron models

    CERN Document Server

    Greenwood, Priscilla E

    2016-01-01

    This book describes a large number of open problems in the theory of stochastic neural systems, with the aim of enticing probabilists to work on them. This includes problems arising from stochastic models of individual neurons as well as those arising from stochastic models of the activities of small and large networks of interconnected neurons. The necessary neuroscience background to these problems is outlined within the text, so readers can grasp the context in which they arise. This book will be useful for graduate students and instructors providing material and references for applying probability to stochastic neuron modeling. Methods and results are presented, but the emphasis is on questions where additional stochastic analysis may contribute neuroscience insight. An extensive bibliography is included. Dr. Priscilla E. Greenwood is a Professor Emerita in the Department of Mathematics at the University of British Columbia. Dr. Lawrence M. Ward is a Professor in the Department of Psychology and the Brain...

  14. Clinical outcomes of laparoscopic surgery for advanced transverse and descending colon cancer: a single-center experience.

    Science.gov (United States)

    Yamamoto, Masashi; Okuda, Junji; Tanaka, Keitaro; Kondo, Keisaku; Tanigawa, Nobuhiko; Uchiyama, Kazuhisa

    2012-06-01

    The role of laparoscopic surgery in management of transverse and descending colon cancer remains controversial. The aim of the present study is to investigate the short-term and oncologic long-term outcomes associated with laparoscopic surgery for transverse and descending colon cancer. This cohort study analyzed 245 patients (stage II disease, n = 70; stage III disease, n = 63) who underwent resection of transverse and descending colon cancers, including 200 laparoscopic surgeries (LAC) and 45 conventional open surgeries (OC) from December 1996 to December 2010. Short-term and oncologic long-term outcomes were recorded. The operative time was longer in the LAC group than in the OC group. However, intraoperative blood loss was significantly lower and postoperative recovery time was significantly shorter in the LAC group than in the OC group. The 5-year overall and disease-free survival rates for patients with stage II were 84.9% and 84.9% in the OC group and 93.7% and 90.0% in the LAC group, respectively. The 5-year overall and disease-free survival rates for patients with stage III disease were 63.4% and 54.6% in the OC group and 66.7% and 56.9% in the LAC group, respectively. Use of laparoscopic surgery resulted in acceptable short-term and oncologic outcomes in patients with advanced transverse and descending colon cancer.

  15. Evidence for modulation of pericryptal sheath myofibroblasts in rat descending colon by Transforming Growth Factor β and Angiotensin II.

    Directory of Open Access Journals (Sweden)

    Pedley Kevin C

    2002-02-01

    Full Text Available Abstract Background Absorption of water and Na+ in descending colonic crypts is dependent on the barrier function of the surrounding myofibroblastic pericryptal sheath. Here the effects of high and low Na+ diets and exposure to whole body ionising radiation on the growth and activation of the descending colonic pericryptal myofibroblasts are evaluated. In addition the effect of a post-irradiation treatment with the angiotensin converting enzyme inhibitor Captopril was investigated. Methods The levels of Angiotensin II type 1 receptor (AT1, ACE, collagen type IV, transforming growth factor-β type 1 receptor (TGF-βR1, OB cadherin and α-smooth muscle actin in both descending colon and caecum were evaluated, using immunocytochemistry and confocal microscopy, in rats fed on high and low Na+ diets (LS. These parameters were also determined during 3 months post-irradiation with 8Gy from a 60Co source in the presence and absence of the angiotensin converting enzyme inhibitor, Captopril. Results Increases in AT1 receptor (135.6% ± 18.3, P Conclusions These results demonstrate an activation of descending colonic myofibroblasts to trophic stimuli, or irradiation, which can be attenuated by Captopril, indicative of local trophic control by angiotensin II and TGF-β release.

  16. Populations of subplate and interstitial neurons in fetal and adult human telencephalon.

    Science.gov (United States)

    Judaš, Miloš; Sedmak, Goran; Pletikos, Mihovil; Jovanov-Milošević, Nataša

    2010-10-01

    In the adult human telencephalon, subcortical (gyral) white matter contains a special population of interstitial neurons considered to be surviving descendants of fetal subplate neurons [Kostovic & Rakic (1980) Cytology and the time of origin of interstitial neurons in the white matter in infant and adult human and monkey telencephalon. J Neurocytol9, 219]. We designate this population of cells as superficial (gyral) interstitial neurons and describe their morphology and distribution in the postnatal and adult human cerebrum. Human fetal subplate neurons cannot be regarded as interstitial, because the subplate zone is an essential part of the fetal cortex, the major site of synaptogenesis and the 'waiting' compartment for growing cortical afferents, and contains both projection neurons and interneurons with distinct input-output connectivity. However, although the subplate zone is a transient fetal structure, many subplate neurons survive postnatally as superficial (gyral) interstitial neurons. The fetal white matter is represented by the intermediate zone and well-defined deep periventricular tracts of growing axons, such as the corpus callosum, anterior commissure, internal and external capsule, and the fountainhead of the corona radiata. These tracts gradually occupy the territory of transient fetal subventricular and ventricular zones.The human fetal white matter also contains distinct populations of deep fetal interstitial neurons, which, by virtue of their location, morphology, molecular phenotypes and advanced level of dendritic maturation, remain distinct from subplate neurons and neurons in adjacent structures (e.g. basal ganglia, basal forebrain). We describe the morphological, histochemical (nicotinamide-adenine dinucleotide phosphate-diaphorase) and immunocytochemical (neuron-specific nuclear protein, microtubule-associated protein-2, calbindin, calretinin, neuropeptide Y) features of both deep fetal interstitial neurons and deep (periventricular

  17. Genome-wide Ancestry and Demographic History of African-Descendant Maroon Communities from French Guiana and Suriname.

    Science.gov (United States)

    Fortes-Lima, Cesar; Gessain, Antoine; Ruiz-Linares, Andres; Bortolini, Maria-Cátira; Migot-Nabias, Florence; Bellis, Gil; Moreno-Mayar, J Víctor; Restrepo, Berta Nelly; Rojas, Winston; Avendaño-Tamayo, Efren; Bedoya, Gabriel; Orlando, Ludovic; Salas, Antonio; Helgason, Agnar; Gilbert, M Thomas P; Sikora, Martin; Schroeder, Hannes; Dugoujon, Jean-Michel

    2017-11-02

    The transatlantic slave trade was the largest forced migration in world history. However, the origins of the enslaved Africans and their admixture dynamics remain unclear. To investigate the demographic history of African-descendant Marron populations, we generated genome-wide data (4.3 million markers) from 107 individuals from three African-descendant populations in South America, as well as 124 individuals from six west African populations. Throughout the Americas, thousands of enslaved Africans managed to escape captivity and establish lasting communities, such as the Noir Marron. We find that this population has the highest proportion of African ancestry (∼98%) of any African-descendant population analyzed to date, presumably because of centuries of genetic isolation. By contrast, African-descendant populations in Brazil and Colombia harbor substantially more European and Native American ancestry as a result of their complex admixture histories. Using ancestry tract-length analysis, we detect different dates for the European admixture events in the African-Colombian (1749 CE; confidence interval [CI]: 1737-1764) and African-Brazilian (1796 CE; CI: 1789-1804) populations in our dataset, consistent with the historically attested earlier influx of Africans into Colombia. Furthermore, we find evidence for sex-specific admixture patterns, resulting from predominantly European paternal gene flow. Finally, we detect strong genetic links between the African-descendant populations and specific source populations in Africa on the basis of haplotype sharing patterns. Although the Noir Marron and African-Colombians show stronger affinities with African populations from the Bight of Benin and the Gold Coast, the African-Brazilian population from Rio de Janeiro has greater genetic affinity with Bantu-speaking populations from the Bight of Biafra and west central Africa. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  18. Discovery of magnetic A supergiants: the descendants of magnetic main-sequence B stars

    Science.gov (United States)

    Neiner, Coralie; Oksala, Mary E.; Georgy, Cyril; Przybilla, Norbert; Mathis, Stéphane; Wade, Gregg; Kondrak, Matthias; Fossati, Luca; Blazère, Aurore; Buysschaert, Bram; Grunhut, Jason

    2017-10-01

    In the context of the high resolution, high signal-to-noise ratio, high sensitivity, spectropolarimetric survey BritePol, which complements observations by the BRITE constellation of nanosatellites for asteroseismology, we are looking for and measuring the magnetic field of all stars brighter than V = 4. In this paper, we present circularly polarized spectra obtained with HarpsPol at ESO in La Silla (Chile) and ESPaDOnS at CFHT (Hawaii) for three hot evolved stars: ι Car, HR 3890 and ɛ CMa. We detected a magnetic field in all three stars. Each star has been observed several times to confirm the magnetic detections and check for variability. The stellar parameters of the three objects were determined and their evolutionary status was ascertained employing evolution models computed with the Geneva code. ɛ CMa was already known and is confirmed to be magnetic, but our modelling indicates that it is located near the end of the main sequence, I.e. it is still in a core hydrogen burning phase. ι Car and HR 3890 are the first discoveries of magnetic hot supergiants located well after the end of the main sequence on the Hertzsprung-Russell diagram. These stars are probably the descendants of main-sequence magnetic massive stars. Their current field strength (a few G) is compatible with magnetic flux conservation during stellar evolution. These results provide observational constraints for the development of future evolutionary models of hot stars including a fossil magnetic field.

  19. Value of internal thoracic artery grafting to the left anterior descending coronary artery at coronary reoperation.

    Science.gov (United States)

    Sabik, Joseph F; Raza, Sajjad; Blackstone, Eugene H; Houghtaling, Penny L; Lytle, Bruce W

    2013-01-22

    The study sought to determine if left internal thoracic artery (LITA) grafting of the left anterior descending (LAD) at reoperative coronary artery bypass grafting (CABG) improves patient outcomes. LITA grafting to the LAD is the gold standard for primary CABG, but its value for reoperative CABG is unknown. From January 1985 to January 2007, reoperative CABG was performed in 3,473 patients who did not receive a LITA during their primary CABG and whose anterior myocardium (LAD) was at risk at reoperation: 2,389 had LITA grafting and 1,084 saphenous vein (SV) grafting to the LAD. Propensity matching (908 matched pairs) was used for balanced comparison of outcomes. Follow-up was continued to 20 years post-operatively, with a mean follow-up of 11 ± 8.2 years. Unadjusted hospital mortality was 2.2% and 6.5% in the LITA and SV groups, respectively (p grafting of the LAD at reoperation resulted in an absolute mortality risk reduction of 6.0% and a hazard ratio of 0.85, with number needed to treat of 16 patients. LITA-to-LAD grafting at reoperation is safe and confers a risk-adjusted survival advantage. When appropriate, a LITA should be used to revascularize the LAD at coronary reoperations. Copyright © 2013 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  20. [Occlusion of secondary branches after angioplasty of the left descending coronary artery].

    Science.gov (United States)

    Araújo, E C; Sousa, A G; Nicolela Júnior, E L; Cano, M N; Maldonado, G; Feres, F; Mattos, L A; Pinto, I M; Tanajura, L F; Fontes, V F

    1990-05-01

    To evaluate the incidence and clinical presentation of the occlusion of such secondary branches in patients with single vessel coronary artery disease in the left anterior descending artery, who underwent a first elective and successful PTCA. Two hundred and thirteen side branches of 121 patients considered to be at risk. They were divided into group I (GI-85 side branches, 39.9%), if they originated from the atherosclerotic site; and group II (GII-120 side branches, 61.5%), if their origin would be involved during the balloon inflation. In the GI there were 54 septal branches and 31 diagonal branches, and 36& had angiographic evidence of ostium disease. GII was constituted by 77 septal and 51 diagonal branches, and 7.8% of them had evidence of ostium disease. Seven side branches (3.3%) at risk occluded, 4 from GI (4.7%) and 3 (2.3%) from GII. As for the clinical presentation, 57% of them had angina, where as 28.6% showed minor abnormalities in the ECG. No patient elevated its serum CK-MB, and silent occlusion occurred in 43% of them. Occlusion of side branches is a low incidence phenomenon, which happens more often in septal branches with ostium disease that originates from the atherosclerotic site; that about half of the patient had silent occlusion (43%) or mild ischemic manifestations.

  1. Cytogenetic abnormalities of the descendants of permanent residents of heavily contaminated East Kazakhstan.

    Science.gov (United States)

    Chaizhunusova, Nailya; Madiyeva, Madina; Tanaka, Kimio; Hoshi, Masaharu; Kawano, Noriyuki; Noso, Yoshihiro; Takeichi, Nobuo; Rakhypbekov, Tolebay; Urazalina, Nailya; Dovgal, Galina; Rymbaeva, Tamara; Tokanova, Sholpan; Beisengazina, Meruert; Kembayeva, Kulypash; Inoue, Ken

    2017-11-01

    More than 400 nuclear explosion tests were conducted at the Semipalatinsk Nuclear Test Site (SNTS) and significant radioactive substances were released. The long-term consequences of the activities at the SNTS and the appearance of any hereditary effects remain insufficiently studied about 25 years after the test site was closed. The population living in villages near the SNTS are considered to have been heavily exposed to external and internal radiation. This study aims to perform an assessment and comprehensive cytogenetic analysis of the inhabitants living near the SNTS, and their first-(F1) and second-(F2) generation children. Residents of the East Kazakhstan region living in the area covered by the former SNTS were included in the study. To evaluate the hereditary effects of nuclear testing, comprehensive chromosome analyses were performed in lymphocytes using conventional Giemsa and fluorescent in situ hybridization methods in 115 F1 and F2 descendants in the villages of Dolon and Sarzhal, which were heavily contaminated. The parents of the subjects had permanently lived in the villages. A higher number of stable-type chromosome aberrations such as translocations was found in these residents than in 80 residents of the control area, Kokpecty, which indicates the possibility that radiation had biological effects on the exposed subjects.

  2. Speeches and trajectories of brazilian afro-descendents in higher education

    Directory of Open Access Journals (Sweden)

    Gilberto Ferreira da Silva

    2006-04-01

    Full Text Available In the last decade, one has observed an increase in studies linking the debate over racial relations to specific questions, such as that of power relations, identity, culture, and so forth. This scenario, no matter how widespread, of researches and analyses is not repeated in the more specific field of the pedagogic relations evolved in the process of forming/instructing teachers. Some recent works have focused on this latter aspect, highlighting the histories and paths taken by these professionals who have already graduated from college. Two subjects, however, are lacking research: the first is that African-descendant students in this process of studying to become teacher are not taken in consideration in this context; the second is that the methodology of analysis of the oral interviews is incipient. In a quest to fill in this methodological gap, without excluding the problematic situation above mentioned, the authors built a theoretical model for interpreting the interviews. The goal was not only to work on a description, but to uncover the meaning of the text, by means of an analysis that required understanding how a phenomenon found itself in the context was it was.

  3. Marginal reticular cells: a stromal subset directly descended from the lymphoid tissue organizer

    Directory of Open Access Journals (Sweden)

    Tomoya eKatakai

    2012-07-01

    Full Text Available The architecture of secondary lymphoid organs (SLOs is supported by several nonhematopoietic stromal cells. Currently it is established that two distinct stromal subsets, follicular dendritic cells and fibroblastic reticular cells, play crucial roles in the formation of tissue compartments within SLOs, i.e., the follicle and T zone, respectively. Although stromal cells in the anlagen are essential for SLO development, the relationship between these primordial cells and the subsets in adulthood remains poorly understood. In addition, the roles of stromal cells in the entry of antigens into the compartments through some tissue structures peculiar to SLOs remain unclear. A recently identified stromal subset, marginal reticular cells (MRCs, covers the margin of SLOs that are primarily located in the outer edge of follicles and construct a unique reticulum. MRCs are closely associated with specialized endothelial or epithelial structures for antigen transport. The similarities in marker expression profiles and successive localization during development suggest that MRCs directly descend from organizer stromal cells in the anlagen. Therefore, MRCs are thought to be a crucial stromal component for the organization and function of SLOs.

  4. Dynamics of coronal rain and descending plasma blobs in solar prominences. I. Fully ionized case

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, R.; Soler, R.; Terradas, J. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Zaqarashvili, T. V.; Khodachenko, M. L., E-mail: ramon.oliver@uib.es [Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, A-8042 Graz (Austria)

    2014-03-20

    Observations of active regions and limb prominences often show cold, dense blobs descending with an acceleration smaller than that of free fall. The dynamics of these condensations falling in the solar corona is investigated in this paper using a simple fully ionized plasma model. We find that the presence of a heavy condensation gives rise to a dynamical rearrangement of the coronal pressure that results in the formation of a large pressure gradient that opposes gravity. Eventually this pressure gradient becomes so large that the blob acceleration vanishes or even points upward. Then, the blob descent is characterized by an initial acceleration phase followed by an essentially constant velocity phase. These two stages can be identified in published time-distance diagrams of coronal rain events. Both the duration of the first stage and the velocity attained by the blob increase for larger values of the ratio of blob to coronal density, for larger blob mass, and for smaller coronal temperature. Dense blobs are characterized by a detectable density growth (up to 60% in our calculations) and by a steepening of the density in their lower part, that could lead to the formation of a shock. They also emit sound waves that could be detected as small intensity changes with periods of the order of 100 s and lasting between a few and about 10 periods. Finally, the curvature of falling paths with large radii is only relevant when a very dense blob falls along inclined magnetic field lines.

  5. DYNAMICS OF CORONAL RAIN AND DESCENDING PLASMA BLOBS IN SOLAR PROMINENCES. II. PARTIALLY IONIZED CASE

    Energy Technology Data Exchange (ETDEWEB)

    Oliver, R.; Soler, R.; Terradas, J. [Departament de Física, Universitat de les Illes Balears, E-07122 Palma de Mallorca (Spain); Zaqarashvili, T. V., E-mail: ramon.oliver@uib.es [Institute of Physics, IGAM, University of Graz, Universitätsplatz 5, 8010, Graz (Austria)

    2016-02-20

    Coronal rain clumps and prominence knots are dense condensations with chromospheric to transition region temperatures that fall down in the much hotter corona. Their typical speeds are in the range 30–150 km s{sup −1} and of the order of 10–30 km s{sup −1}, respectively, i.e., they are considerably smaller than free-fall velocities. These cold blobs contain a mixture of ionized and neutral material that must be dynamically coupled in order to fall together, as observed. We investigate this coupling by means of hydrodynamic simulations in which the coupling arises from the friction between ions and neutrals. The numerical simulations presented here are an extension of those of Oliver et al. to the partially ionized case. We find that, although the relative drift speed between the two species is smaller than 1 m s{sup −1} at the blob center, it is sufficient to produce the forces required to strongly couple charged particles and neutrals. The ionization degree has no discernible effect on the main results of our previous work for a fully ionized plasma: the condensation has an initial acceleration phase followed by a period with roughly constant velocity, and, in addition, the maximum descending speed is clearly correlated with the ratio of initial blob to environment density.

  6. Spontaneous comedones on the skin of hairless descendants of Mexican hairless dogs.

    Science.gov (United States)

    Kimura, T; Doi, K

    1996-10-01

    In the first experiment, the skin sebum and humidity, perspiration ability of sweat glands, and histology of spontaneous comedones were examined in hairless descendants of Mexican hairless dogs. The skin of females showed lower humidity than that of males. Some animals with a large number of comedones exhibited remarkably high skin sebum scores. The comedones were distributed throughout the dorsal skin, and a cluster of lesions was found mainly in the limbs and prepuces. The sweat glands showed no perspiration in the sudorific test. Histologically, both infant and adult animals had lesions of micro- and/or "blackhead" comedones. Plugged follicles containing abundant keratic substances associated well-developed sebaceous glands. Spontaneous comedones in the skin of hairless dogs were grossly and histologically similar to the acne vulgaris observed in human beings. The skin of some adult animals showed a large number of protrusive comedones which were solid cystic structures containing organized substances. In the second experiment, three kinds of antiacne agents (sulfur and camphor, sulfur and resorcinol, and ibuprofen piconol) were applied daily to the test sites for one month. These antiacne agents caused prominent extrusion of keratin plugs from follicular sites. The results suggest that the hairless dogs are a predictive model for evaluating the efficacy of antiacne agents proposed for acne treatment.

  7. Descending and ascending trajectories of dialogical analysis: seventh analytic interpretation on the short story "The guerrillero"

    Directory of Open Access Journals (Sweden)

    Danilo Silva Guimarães

    Full Text Available Abstract: The dialogical unity for the analysis of the Self includes the descending intersubjective interpenetration of the psychologist's lens into the self-others' feeling/thinking together with the analytic demonstration concerning the transformations of the objects that participate in the intrapsychological stream of the focused feeling/thinking. The theoretical and methodological issues selected for our present study concern how to make dialogical analysis out of empirical data and how to articulate the analyzed content to the interpretative whole situation from which the researcher and the subject matter are part of. Dialogism does not have a standardized procedure and we are not considering that there is only one correct methodological procedure in dialogical psychology. Nevertheless, discussing some dialogical approaches to a short story from Albalucía Ángel (1979, we found that the starting point for the dialogical analysis should be the mediated relation of the Self with the others, emphasizing the relevance of the extra-verbal concrete situation.

  8. Endovascular Treatment of Descending Thoracic Aortic Aneurysms with the EndoFit Stent-Graft

    International Nuclear Information System (INIS)

    Saratzis, N.; Saratzis, Athanasios; Melas, N.; Ginis, G.; Lioupis, A.; Lykopoulos, D.; Lazaridis, J.; Kiskinis, Dimitrios

    2007-01-01

    Objective. To evaluate the mid-term feasibility, efficacy, and durability of descending thoracic aortic aneurysm (DTAA) exclusion using the EndoFit device (LeMaitre Vascular). Methods. Twenty-three (23) men (mean age 66 years) with a DTAA were admitted to our department for endovascular repair (21 were ASA III+ and 2 refused open repair) from January 2003 to July 2005. Results. Complete aneurysm exclusion was feasible in all subjects (100% technical success). The median follow-up was 18 months (range 8-40 months). A single stent-graft was used in 6 cases. The deployment of a second stent-graft was required in the remaining 17 patients. All endografts were attached proximally, beyond the left subclavian artery, leaving the aortic arch branches intact. No procedure-related deaths have occurred. A distal type I endoleak was detected in 2 cases on the 1 month follow-up CT scan, and was repaired with reintervention and deployment of an extension graft. A nonfatal acute myocardial infarction occurred in 1 patient in the sixth postoperative month. Graft migration, graft infection, paraplegia, cerebral or distal embolization, renal impairment or any other major complications were not observed. Conclusion. The treatment of DTAAs using the EndoFit stent-graft is technically feasible. Mid-term results in this series are promising

  9. Creation of DNA bank on the irradiated people and their descendants

    International Nuclear Information System (INIS)

    Rusinova, G.G.; Adamova, G.V.; Okladnikova, N.D.

    2000-01-01

    Now special interest in the scientific world acquiring the researches on influence of radiation and estimation of the remote consequences of an irradiation on a genome of the man with the help of modern molecular-genetic methods. The decision of this problem has connected with reception and preservation of a hereditary material at cohorts who were exposed to an irradiation. Such cohort are the workers of the first atomic enterprise in Russia. In period of starting of this enterprise the workers were exposed by a chronic irradiation and combined radiation (Pu-239) in more then permissible doses. Now average age of these workers exceed 65 years. With the purpose of study of genetic consequences of an irradiation in Branch N 1 the Biophysics Institute Russian Federation (Ozyorsk, Chelyabinsk region) DNA Bank is creating. The methodological and methodical bases of its creation are developed. The creation of DNA Bank will enable widely to use the saved genetic material in the newest techniques for the analysis mini - and microsatellite DNA, structural genes (genes of a reparation and stress-response genes), both in somatic (parents), and in germinal cells of the individuals (descendants). The selection of families for DNA study is rather wide - one of the parents is irradiated or both parents have exposed to radiation. DNA, received from sputum and blood serum of the workers with incorporation Pu (the group of risk) will allow to investigate a role of some genes (K-ras, p16, p53) in development of tumor process. (author)

  10. Descending necrotizing mediastinitis with diffuse ST elevation mimicking pericarditis: a case report.

    Science.gov (United States)

    Cho, Young Soon; Choi, Jae Hyung

    2014-10-01

    Descending necrotizing mediastinitis (DNM) is a potentially fatal disease that requires aggressive treatment, including mediastinal exploration. The inflammation associated with DNM may involve the heart, which produces acute changes in the electrocardiogram (ECG). As a result, the ECG may mimic pericarditis, causing some diagnostic confusion. The objectives of this case report are to describe a case of DNM presenting electrocardiographically with pericarditis, and to discuss how to differentiate between benign viral pericarditis and DNM, and the management of these two diseases. We present the case of a previously healthy 50-year-old man who presented to the Emergency Department for chest pain and presumed pericarditis. The patient presented with ST elevation on multiple leads on ECG, tenderness in the neck, widened mediastinum on the chest radiograph, and nonspecific laboratory test results. Echocardiography revealed normal ventricle function and the presence of mild pericardial effusion. The emergency physician performed contrast-enhanced neck computed tomography (CT) to rule out deep-neck infection. The CT scan showed marginal rim-enhancing abscesses in the retropharyngeal, bilateral submandibular, and anterior visceral spaces with extension into the thoracic cavity. Contrast-enhanced chest CT was performed consecutively. The final diagnosis was deep-neck infection with DNM. The patient underwent mediastinoscopy-assisted drainage and neck fasciotomy twice and received 7 weeks of therapy with intravenous meropenem. The present case highlights the importance of considering a mediastinal cause for acute ECG changes. Copyright © 2014 Elsevier Inc. All rights reserved.

  11. Velocity distribution around a sphere descending in a salt-stratified water

    Science.gov (United States)

    Hanazaki, Hideshi; Akiyama, Shinsaku; Okino, Shinya

    2017-11-01

    When a sphere descends at constant speed in a salt-stratified water, a thin and high-speed jet is often generated above the sphere. The phenomenon has first been observed by shadowgraph and then has been investigated numerically. In this study, a systematic measurement by particle image velocimetry (PIV) has been performed for a wide range of Froude number Fr and Reynolds number Re , to actually observe the numerically simulated velocity distributions and confirm the accuracy of the numerical simulations for a very high Schmidt (Prandtl) number of Sc =(Pr =) 700 . The results show that the radius of the jet is proportional to both Fr 1 / 2 and Re - 1 / 2 , meaning that it is proportional to √{ Fr / Re } (when F < 1). The boundary layer on the sphere surface has a thickness comparable to the jet radius, and it is also proportional to √{ Fr / Re }. These results are in agreement with the recent numerical simulations and a simple dimensional analysis. Typical diverging internal-wave patterns, whose vertical wavelength has been predicted to be proportional to Fr , could also be observed.

  12. Descending perineum syndrome: a review of the presentation, diagnosis, and management.

    Science.gov (United States)

    Chaudhry, Zaid; Tarnay, Christopher

    2016-08-01

    Defecatory dysfunction is a relatively common and challenging problem among women and one that practicing pelvic reconstructive surgeons and gynecologists deal with frequently. A subset of defecatory dysfunction includes obstructed defecation, which can have multiple causes, one of which is descending perineum syndrome (DPS). A literature search was performed to identify the pathophysiology, diagnosis, and management of DPS. Although DPS has been described in the literature for many decades, it is still uncommonly diagnosed and difficult to manage. A high index of suspicion combined with physical examination consistent with excess perineal descent, patient symptom assessment, and imaging in the form of defecography are required for the diagnosis to be accurately made. Primary management options of DPS include conservative measures consisting of bowel regimens and biofeedback. Although various surgical approaches have been described in limited case series, no compelling evidence can be demonstrated at this point to support surgical intervention. Knowledge of DPS is essential for the practicing pelvic reconstructive surgeon to make a timely diagnosis, avoid harmful treatments, and initiate therapy early on.

  13. ULTRASTRUCTURAL CHANGES OF THE NEURONAL ...

    African Journals Online (AJOL)

    ULTRASTRUCTURAL CHANGES OF THE NEURONAL COMPONENT IN THE DETRUSOR MUSCLE FOLLOWING SACRAL ROOT STIMULATION OF DECENTRALIZED ... Early sacral root electric stimulation decreased the incidence of neuronal degeneration in decentralized detrusor muscle, together with improving the ...

  14. Neuronal survival in the brain: neuron type-specific mechanisms

    DEFF Research Database (Denmark)

    Pfisterer, Ulrich Gottfried; Khodosevich, Konstantin

    2017-01-01

    Neurogenic regions of mammalian brain produce many more neurons that will eventually survive and reach a mature stage. Developmental cell death affects both embryonically produced immature neurons and those immature neurons that are generated in regions of adult neurogenesis. Removal of substantial...... for survival in a certain brain region. This review focuses on how immature neurons survive during normal and impaired brain development, both in the embryonic/neonatal brain and in brain regions associated with adult neurogenesis, and emphasizes neuron type-specific mechanisms that help to survive for various...

  15. Neuronal substrate of eating disorders

    OpenAIRE

    Timofeeva, Elena; Calvez, Juliane

    2014-01-01

    Eating disorders are devastating and life-threatening psychiatric diseases. Although clinical and experimental investigations have significantly progressed in discovering the neuronal causes of eating disorders, the exact neuronal and molecular mechanisms of the development and maintenance of these pathologies are not fully understood. The complexity of the neuronal substrate of eating disorders hampers progress in revealing the precise mechanisms. The present re...

  16. Cultures of Cerebellar Granule Neurons

    OpenAIRE

    sprotocols

    2014-01-01

    Authors: Parizad M. Bilimoria and Azad Bonni1 Corresponding author ([]()) ### INTRODUCTION Primary cultures of granule neurons from the post-natal rat cerebellum provide an excellent model system for molecular and cell biological studies of neuronal development and function. The cerebellar cortex, with its highly organized structure and few neuronal subtypes, offers a well-characterized neural circuitry. Many fundamental insight...

  17. Motor neuron disease in blacks

    African Journals Online (AJOL)

    1989-08-19

    Aug 19, 1989 ... We reported earlier that motor neuron disease occurs more commonly among blacks than Parkinson's disease, which is relatively rare in this race group.! The hypothesis that these conditions, and other neuronal abiotrophies, are the result of previous subclinical neuronal insult and subsequent age-related.

  18. Allelic lineages of the ficolin genes (FCNs are passed from ancestral to descendant primates.

    Directory of Open Access Journals (Sweden)

    Tina Hummelshøj

    Full Text Available The ficolins recognize carbohydrates and acetylated compounds on microorganisms and dying host cells and are able to activate the lectin pathway of the complement system. In humans, three ficolin genes have been identified: FCN1, FCN2 and FCN3, which encode ficolin-1, ficolin-2 and ficolin-3, respectively. Rodents have only two ficolins designated ficolin-A and ficolin-B that are closely related to human ficolin-1, while the rodent FCN3 orthologue is a pseudogene. Ficolin-2 and ficolin-3 have so far only been observed in humans. Thus, we performed a systematic investigation of the FCN genes in non-human primates. The exons and intron-exon boundaries of the FCN1-3 genes were sequenced in the following primate species: chimpanzee, gorilla, orangutan, rhesus macaque, cynomolgus macaque, baboon and common marmoset. We found that the exon organisation of the FCN genes was very similar between all the non-human primates and the human FCN genes. Several variations in the FCN genes were found in more than one primate specie suggesting that they were carried from one species to another including humans. The amino acid diversity of the ficolins among human and non-human primate species was estimated by calculating the Shannon entropy revealing that all three proteins are generally highly conserved. Ficolin-1 and ficolin-2 showed the highest diversity, whereas ficolin-3 was more conserved. Ficolin-2 and ficolin-3 were present in non-human primate sera with the same characteristic oligomeric structures as seen in human serum. Taken together all the FCN genes show the same characteristics in lower and higher primates. The existence of trans-species polymorphisms suggests that different FCN allelic lineages may be passed from ancestral to descendant species.

  19. Contemporary economic and clinical evaluations of endovascular repair for intact descending thoracic aortic aneurysms.

    Science.gov (United States)

    Silingardi, Roberto; Gennai, Stefano; Coppi, Giovanni; Chester, Johanna; Marcheselli, Luigi; Brunetti, Massimo

    2017-12-01

    The aim of this study was to assess clinical and contemporary costs associated with elective endovascular repair of intact descending thoracic aortic aneurysms (DTAA) into the mid-term follow-up. A retrospective review of a prospectively maintained clinical database including 29 consecutive patients from July 2005 to December 2009 treated with elective endovascular repair (TEVAR) or TEVAR and surgical infrarenal repair (hybrid) of intact DTAA was performed. Mean age was 74.5 years old (±7.1). Primary clinical endpoints include mortality and major morbidity. Additionally a comprehensive economic appraisal of individual in-hospital and follow-up costs was executed. Economic endpoints include in-hospital and follow-up costs and patient discharge status. Elective endovascular and open repairs' clinical and economical outcomes in contemporary literature were assessed for comparison according to PRISMA standards. Immediate mortality was 6.9% (1/24 TEVAR and 1/5 hybrid). Three respiratory complications were recorded (11%; 2 TEVAR, 1 hybrid). Renal and cardiac complication rates were 7.4% (1 TEVAR, 1 hybrid) and 3.7% (1 TEVAR) respectively. Routine discharge home was achieved for 85% of patients (95.7% TEVAR, 25% hybrid). Three endoleaks were treated throughout the follow-up (2 TEVAR, 1 hybrid; mean 30.4 mo, ±19.9) rendering an 11% (3/27) reintervention rate. Average immediate cost was €21,976.87 for elective endovascular repair and €33,783.21 for elective endovascular hybrid repair. Additional reintervention and routine follow-up costs augmented immediate costs by 12.4%. This study supports satisfying immediate clinical outcomes for TEVAR and TEVAR+surgical infrarenal procedures. Although limited by a small population size and difficulties in economic comparisons, this study presents the real world social and economic cost scenario for both elective TEVAR and TEVAR hybrid treatment of DTAA of both the in-hospital and at mid term follow-up periods.

  20. Increased wall stress of saccular versus fusiform aneurysms of the descending thoracic aorta.

    Science.gov (United States)

    Nathan, Derek P; Xu, Chun; Pouch, Alison M; Chandran, Krishnan B; Desjardins, Benoit; Gorman, Joseph H; Fairman, Ron M; Gorman, Robert C; Jackson, Benjamin M

    2011-11-01

    Repair of fusiform descending thoracic aortic aneurysms (DTAs) is indicated when aneurysmal diameter exceeds a certain threshold; however, diameter-related indications for repair of saccular DTA are less well established. Human subjects with fusiform (n = 17) and saccular (n = 17) DTAs who underwent computed tomographic angiography were identified. Patients with aneurysms related to connective tissue disease were excluded. The thoracic aorta was segmented, reconstructed, and triangulated to create a mesh. Finite element analysis was performed using a pressure load of 120 mm Hg and a uniform aortic wall thickness of 3.2 mm to compare the pressure-induced wall stress of fusiform and saccular DTAs. The mean maximum diameter of the fusiform DTAs (6.0 ± 1.5 cm) was significantly greater (p = 0.006) than that of the saccular DTAs (4.4 ± 1.8 cm). However, mean peak wall stress of the fusiform DTAs (0.33 ± 0.15 MPa) was equivalent to that of the saccular DTAs (0.30 ± 0.14 MPa), as found by using an equivalence threshold of 0.15 MPa. The mean normalized wall stress (peak wall stress divided by maximum aneurysm radius) of the saccular DTAs was greater than that of the fusiform DTAs (0.16 ± 0.09 MPa/cm vs. 0.11 ± 0.03 MPa/cm, p = 0.035). The normalized wall stress for saccular DTA is greater than that for fusiform DTA, indicating that geometric factors such as aneurysm shape influence wall stress. These results suggest that saccular aneurysms may be more prone to rupture than fusiform aneurysms of similar diameter, provide a theoretical rationale for the repair of saccular DTAs at a smaller diameter, and suggest investigation of the role of biomechanical modeling in surgical decision making is warranted. Copyright © 2011. Published by Elsevier Inc.

  1. Spinal fMRI reveals decreased descending inhibition during secondary mechanical hyperalgesia.

    Directory of Open Access Journals (Sweden)

    Torge Rempe

    Full Text Available Mechanical hyperalgesia is one distressing symptom of neuropathic pain which is explained by central sensitization of the nociceptive system. This sensitization can be induced experimentally with the heat/capsaicin sensitization model. The aim was to investigate and compare spinal and supraspinal activation patterns of identical mechanical stimulation before and after sensitization using functional spinal magnetic resonance imaging (spinal fMRI. Sixteen healthy subjects (6 female, 10 male, mean age 27.2 ± 4.0 years were investigated with mechanical stimulation of the C6 dermatome of the right forearm during spinal fMRI. Testing was always performed in the area outside of capsaicin application (i.e. area of secondary mechanical hyperalgesia. During slightly noxious mechanical stimulation before sensitization, activity was observed in ipsilateral dorsolateral pontine tegmentum (DLPT which correlated with activity in ipsilateral spinal cord dorsal gray matter (dGM suggesting activation of descending nociceptive inhibition. During secondary mechanical hyperalgesia, decreased activity was observed in bilateral DLPT, ipsilateral/midline rostral ventromedial medulla (RVM, and contralateral subnucleus reticularis dorsalis, which correlated with activity in ipsilateral dGM. Comparison of voxel-based activation patterns during mechanical stimulation before/after sensitization showed deactivations in RVM and activations in superficial ipsilateral dGM. This study revealed increased spinal activity and decreased activity in supraspinal centers involved in pain modulation (SRD, RVM, DLPT during secondary mechanical hyperalgesia suggesting facilitation of nociception via decreased endogenous inhibition. Results should help prioritize approaches for further in vivo studies on pain processing and modulation in humans.

  2. Descending projections of the hamster intergeniculate leaflet: relationship to the sleep/arousal and visuomotor systems

    Science.gov (United States)

    Morin, Lawrence P.; Blanchard, Jane H.

    2005-01-01

    The intergeniculate leaflet (IGL), homolog of the primate pregeniculate nucleus, modulates circadian rhythms. However, its extensive anatomical connections suggest that it may regulate other systems, particularly those for visuomotor function and sleep/arousal. Here, descending IGL-efferent pathways are identified with the anterograde tracer, Phaseolus vulgaris leucoagglutinin, with projections to over 50 brain stem nuclei. Projections of the ventral lateral geniculate are similar, but more limited. Many of the nuclei with IGL afferents contribute to circuitry governing visuomotor function. These include the oculomotor, trochlear, anterior pretectal, Edinger-Westphal, and the terminal nuclei; all layers of the superior colliculus, interstitial nucleus of the medial longitudinal fasciculus, supraoculomotor periaqueductal gray, nucleus of the optic tract, the inferior olive, and raphe interpositus. Other target nuclei are known to be involved in the regulation of sleep, including the lateral dorsal and pedunculopontine tegmentum. The dorsal raphe also receives projections from the IGL and may contribute to both sleep/arousal and visuomotor function. However, the locus coeruleus and medial vestibular nucleus, which contribute to sleep and eye movement regulation and which send projections to the IGL, do not receive reciprocal projections from it. The potential involvement of the IGL with the sleep/arousal system is further buttressed by existing evidence showing IGL-efferent projections to the ventrolateral preoptic area, dorsomedial, and medial tuberal hypothalamus. In addition, the great majority of all regions receiving IGL projections also receive input from the orexin/hypocretin system, suggesting that this system contributes not only to the regulation of sleep, but to eye movement control as well.

  3. Risk Factors Affecting the Prognosis of Descending Necrotizing Mediastinitis From Odontogenic Infection.

    Science.gov (United States)

    Qu, Luyao; Liang, Xiang; Jiang, Bin; Qian, Wentao; Zhang, Weijie; Cai, Xieyi

    2017-12-13

    Descending necrotizing mediastinitis (DNM) is a serious complication of head and neck infections and has an excessively high mortality rate owing to the lack of understanding of DNM. We assessed the clinical characteristics, diagnosis, treatment, and outcomes of odontogenic DNM and evaluated the risk factors affecting the prognosis of DNM to provide an up-to-date overview for clinical practice. We performed a retrospective cohort study, enrolling a sample of patients with DNM due to odontogenic infection who had been referred from January 2013 to December 2016. The patients were classified into surviving and deceased groups. The primary predictors in the present study were the presence of multiple comorbidities, complications, demographic data (age, gender), laboratory tests (white blood cell count, percentage of neutrophils), and time (duration before diagnosis, length of hospital stay). The primary outcome variable was the patient outcome (dead or alive). The continuous variables were evaluated using Student's t test or the t test, and the categorical and binary variables were compared using the χ 2 test or Fisher exact test. A total of 81 patients (68 men, 13 women; median age of 57.2 ± 12.2 years) were included. The mortality was 4.9%. The most frequent cause of DNM was periapical periodontitis (66.7%). The lower posterior molars were involved in 39.5% of the cases. Treatment consisted of antibiotic therapy, aggressive transcervical mediastinal drainage (n = 74), and thoracotomy (n = 7). The associated risk factors for mortality were complications (P aggressive mediastinal drainage are fundamental to reducing the incidence of complications and the development of septic shock in odontogenic DNM patients. Copyright © 2018 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  4. Dipyridamole coronary flow reserve stratifies prognosis in acute coronary syndrome patients without left anterior descending disease.

    Science.gov (United States)

    Ascione, Luigi; Carlomagno, Guido; Sordelli, Chiara; Iengo, Raffaele; Monda, Vittorio; Severino, Sergio; Merenda, Raffaele; D'Andrea, Antonello; Caso, Pio

    2013-09-01

    Coronary flow reserve (CFR) assessment by transthoracic ultrasound of the left anterior descending (LAD) artery during dipyridamole stress echocardiography has been shown to predict prognosis in large unselected populations. Low values of CFR are strongly correlated with significant stenosis of the LAD; aim of the present study was to assess the prognostic impact of CFR in patients recovering from an acute coronary syndrome (ACS) with proven absence of LAD disease. From an overall cohort of 325 patients with ACS who underwent a high-dose dipyridamole stress with combined assessment of CFR in the LAD and wall motion, 152 patients without LAD disease (stenosis <50%) were included in the present analysis; all subjects underwent coronary angiography and were subsequently monitored for the incidence of major cardiac events (MACE). After a median follow-up of 29 months, 22 patients developed MACE. Patients who experienced MACE differed from stable patients in terms of age, prevalence of diabetes, and CFR. Receiver-operating characteristic curve analysis defined a CFR <2.25 as the optimal cut point for prediction of MACE. Cox multivariable analysis for the prediction of MACE demonstrated independent predictive value only for CFR <2.25, smoking status, and number of stenotic vessels at angiogram. In high-risk patients with ACS, even in the absence of LAD disease, CFR significantly improves prediction of adverse events when added to standard evaluation. This finding supports a role of CFR in the risk stratification early after ACS and is in context with the concept that CFR reflects global atherosclerotic burden, endothelial dysfunction, and microvascular damage, more than just mirroring focal LAD disease.

  5. Descendants of Hardship: Prevalence, Drivers and Scarring Effects of Social Exclusion in Childhood

    Directory of Open Access Journals (Sweden)

    J. Cok Vrooman

    2015-07-01

    Full Text Available The social exclusion of children is problematic for two reasons. Young people typically inherit their marginal position from their family, and therefore cannot be held responsible for their hardship themselves; and social exclusion in childhood may affect their wellbeing and subsequent development, possibly leading to a “scarring effect” in later life. In this contribution we develop an instrument for measuring social exclusion among children. Social exclusion is regarded as a theoretical construct with four sub-dimensions: material deprivation, limited social participation, inadequate access to social rights, and a lack of normative integration. First we analyse data from a survey of 2,200 Dutch children, which contains a large set of social exclusion items. We applied nonlinear principal components analysis in order to construct a multidimensional scale. Measured in this way, the prevalence of social exclusion among children is 4.5%. Boys and children living in large families are more likely to experience social exclusion than girls and children with few siblings. The parental level of education and dependency on social security benefits are also important driving factors of childhood social exclusion. Subsequently we investigate the scarring effect. Longitudinal administrative income and household data covering 25 years were combined with a new survey of just under 1,000 Dutch adults, a third of whom were poor as a child. The survey assessed their past and current degree of social exclusion, and their health and psychosocial development, educational career, past family circumstances, etc. In an absolute sense scarring turns out to have been limited during this period: a very large majority of those who were poor or excluded as a child are above the threshold values in adult life. However, the “descendants of hardship” are still more likely to be socially excluded as adults than people who grew up in more favourable conditions. A

  6. [Arterial prehypertension in slave-descendant communities in southeast Bahia State, Brazil].

    Science.gov (United States)

    Bezerra, Vanessa Moraes; Andrade, Amanda Cristina de Souza; Medeiros, Danielle Souto de; Caiaffa, Waleska Teixeira

    2017-10-26

    Arterial prehypertension is a precursor of arterial hypertension and a risk factor for cardiovascular diseases. Vulnerable populations are more prone to this condition due to difficulties in access to health services. A previous study in quilombola communities (descendants of African slaves) reported a high prevalence of arterial hypertension. The current study aimed to estimate the prevalence of arterial prehypertension in quilombolas and to assess associated factors. This was a cross-sectional population-based study in individuals 18 years and older. Prehypertension was defined as arterial systolic pressure ≥ 121mmHg and < 140mmHg and/or diastolic ≥ 81mmHg and < 90mmHg. Multivariate Poisson regression with robust variance was used. Population-attributable fractions (PAF) were also calculated for the modifiable associated factors. Prevalence of prehypertension was 55% (95%CI: 50.2-59.7). Male gender (PR = 1.54), 1 to 4 complete years of schooling (PR = 1.44), and BMI classified as overweight (PR = 1.39) and obesity (PR = 1.87) showed positive association with prehypertension. Higher attributable fractions were observed in individuals with 1 to 4 years of schooling (13.7%) and those classified as overweight (9.35%) and obese (4.6%). Prevalence of prehypertension in quilombola communities was high, and its identification may allow screening and awareness-raising in a group with increased risk of cardiovascular disease and progression to full-blown hypertension. The study highlights the need for broad access to health services and specific measures for orientation, prevention, and health promotion in this population.

  7. Italian citizenship and the descendants of Italian citizens emigrated in Colombia. Removing a social injustice

    Directory of Open Access Journals (Sweden)

    Massimiliano Castellari

    2011-11-01

    Full Text Available Law is often the source of social discriminations, but, at the same time, it can be thekey to delete these social discriminations. The authors try to give an example of thisphenomenon, by analyzing the impact of the Italian citizenship’s rules over the descendantsof the Italian citizens emigrated abroad and, especially, in South America.Indeed, according to the former Italian law, only fathers could transmit iure sanguinisthe citizenship to their children: moreover, women automatically lost theItalian citizenship if they get a foreign citizenship by concluding a marriage witha foreign husband.These rules hardly discriminate the Italian women emigrated abroad and, especially,their descendants who were prevented to get the Italian’s citizenship.These discriminatory rules were finally deleted by the Italian Constitutional Courtin the Seventies and in the Eighties: however, the effects of those rules still persisted,since the decision of the Constitutional Court could not overcome the temporal limit of the entry into force of the Constitution (01.01.1948 and, therefore, could not“cover” the discriminatory facts occurred before that date.Finally in 2009, the Italian Supreme Court, by extending the effects ratione temporisof the decisions of the Constitutional Court, “reopened the doors” of the Italiancitizenship to a huge number of Italian citizenship born from Italian women beforethe 01.01.1948.Therefore, the authors focus on the social impact of this decision for all the potentialItalian citizens living in South America and try to assess its juridical effects overthe Italian law.

  8. When is visual information used to control locomotion when descending a kerb?

    Directory of Open Access Journals (Sweden)

    John G Buckley

    Full Text Available BACKGROUND: Descending kerbs during locomotion involves the regulation of appropriate foot placement before the kerb-edge and foot clearance over it. It also involves the modulation of gait output to ensure the body-mass is safely and smoothly lowered to the new level. Previous research has shown that vision is used in such adaptive gait tasks for feedforward planning, with vision from the lower visual field (lvf used for online updating. The present study determined when lvf information is used to control/update locomotion when stepping from a kerb. METHODOLOGY/PRINCIPAL FINDINGS: 12 young adults stepped down a kerb during ongoing gait. Force sensitive resistors (attached to participants' feet interfaced with an high-speed PDLC 'smart glass' sheet, allowed the lvf to be unpredictably occluded at either heel-contact of the penultimate or final step before the kerb-edge up to contact with the lower level. Analysis focussed on determining changes in foot placement distance before the kerb-edge, clearance over it, and in kinematic measures of the step down. Lvf occlusion from the instant of final step contact had no significant effect on any dependant variable (p>0.09. Occlusion of the lvf from the instant of penultimate step contact had a significant effect on foot clearance and on several kinematic measures, with findings consistent with participants becoming uncertain regarding relative horizontal location of the kerb-edge. CONCLUSION/SIGNIFICANCE: These findings suggest concurrent feedback of the lower limb, kerb-edge, and/or floor area immediately in front/below the kerb is not used when stepping from a kerb during ongoing gait. Instead heel-clearance and pre-landing-kinematic parameters are determined/planned using lvf information acquired in the penultimate step during the approach to the kerb-edge, with information related to foot placement before the kerb-edge being the most salient.

  9. Genetic inactivation of glutamate neurons in the rat sublaterodorsal tegmental nucleus recapitulates REM sleep behaviour disorder.

    Science.gov (United States)

    Valencia Garcia, Sara; Libourel, Paul-Antoine; Lazarus, Michael; Grassi, Daniela; Luppi, Pierre-Hervé; Fort, Patrice

    2017-02-01

    SEE SCHENCK AND MAHOWALD DOI101093/AWW329 FOR A SCIENTIFIC COMMENTARY ON THIS ARTICLE: Idiopathic REM sleep behaviour disorder is characterized by the enactment of violent dreams during paradoxical (REM) sleep in the absence of normal muscle atonia. Accumulating clinical and experimental data suggest that REM sleep behaviour disorder might be due to the neurodegeneration of glutamate neurons involved in paradoxical sleep and located within the pontine sublaterodorsal tegmental nucleus. The purpose of the present work was thus to functionally determine first, the role of glutamate sublaterodorsal tegmental nucleus neurons in paradoxical sleep and second, whether their genetic inactivation is sufficient for recapitulating REM sleep behaviour disorder in rats. For this goal, we first injected two retrograde tracers in the intralaminar thalamus and ventral medulla to disentangle neuronal circuits in which sublaterodorsal tegmental nucleus is involved; second we infused bilaterally in sublaterodorsal tegmental nucleus adeno-associated viruses carrying short hairpin RNAs targeting Slc17a6 mRNA [which encodes vesicular glutamate transporter 2 (vGluT2)] to chronically impair glutamate synaptic transmission in sublaterodorsal tegmental nucleus neurons. At the neuroanatomical level, sublaterodorsal tegmental nucleus neurons specifically activated during paradoxical sleep hypersomnia send descending efferents to glycine/GABA neurons within the ventral medulla, but not ascending projections to the intralaminar thalamus. These data suggest a crucial role of sublaterodorsal tegmental nucleus neurons rather in muscle atonia than in paradoxical sleep generation. In line with this hypothesis, 30 days after adeno-associated virus injections into sublaterodorsal tegmental nucleus rats display a decrease of 30% of paradoxical sleep daily quantities, and a significant increase of muscle tone during paradoxical sleep concomitant to a tremendous increase of abnormal motor dream

  10. Emergence of Serotonergic Neurons After Spinal Cord Injury in Turtles

    Directory of Open Access Journals (Sweden)

    Gabriela Fabbiani

    2018-03-01

    Full Text Available Plasticity of neural circuits takes many forms and plays a fundamental role in regulating behavior to changing demands while maintaining stability. For example, during spinal cord development neurotransmitter identity in neurons is dynamically adjusted in response to changes in the activity of spinal networks. It is reasonable to speculate that this type of plasticity might occur also in mature spinal circuits in response to injury. Because serotonergic signaling has a central role in spinal cord functions, we hypothesized that spinal cord injury (SCI in the fresh water turtle Trachemys scripta elegans may trigger homeostatic changes in serotonergic innervation. To test this possibility we performed immunohistochemistry for serotonin (5-HT and key molecules involved in the determination of the serotonergic phenotype before and after SCI. We found that as expected, in the acute phase after injury the dense serotonergic innervation was strongly reduced. However, 30 days after SCI the population of serotonergic cells (5-HT+ increased in segments caudal to the lesion site. These cells expressed the neuronal marker HuC/D and the transcription factor Nkx6.1. The new serotonergic neurons did not incorporate the thymidine analog 5-bromo-2′-deoxyuridine (BrdU and did not express the proliferating cell nuclear antigen (PCNA indicating that novel serotonergic neurons were not newborn but post-mitotic cells that have changed their neurochemical identity. Switching towards a serotonergic neurotransmitter phenotype may be a spinal cord homeostatic mechanism to compensate for the loss of descending serotonergic neuromodulation, thereby helping the outstanding functional recovery displayed by turtles. The 5-HT1A receptor agonist (±-8-Hydroxy-2-dipropylaminotetralin hydrobromide (8-OH-DPAT blocked the increase in 5-HT+ cells suggesting 5-HT1A receptors may trigger the respecification process.

  11. Assessment of transmission in specific descending pathways in relation to gait and balance following spinal cord injury

    DEFF Research Database (Denmark)

    Barthélemy, Dorothy; Willerslev-Olsen, Maria; Lundell, Henrik

    2015-01-01

    Human bipedal gait requires supraspinal control and gait is consequently severely impaired in most persons with spinal cord injury (SCI). Little is known of the contribution of lesion of specific descending pathways to the clinical manifestations of gait deficits. Here, we assessed transmission...... in descending pathways using imaging and electrophysiological techniques and correlated them with clinical measures of impaired gait in persons with SCI. Twenty-five persons with SCI participated in the study. Functional assessment of gait included the Walking Index for Spinal Cord Injury (WISCI), the Timed...... correlation to the assessments of gait function (r(2)~0.4). 6MWT and gait speed were correlated to atrophy of the lateral sections of the spinal cord bilaterally, whereas BBS was correlated to atrophy of both lateral and ventral sections of the spinal cord. No significant correlation was observed between...

  12. Primary Mucinous Cystadenoma Arising from Behind the Posterior Peritoneum of the Descending Colon in a Child: A Case Report

    Directory of Open Access Journals (Sweden)

    Tsuyoshi Tamura

    2003-10-01

    Full Text Available This is the first report of a primary mucinous cystadenoma (MCA arising from behind the posterior peritoneum of the descending colon in a paediatric patient. A large intra-abdominal cystic lesion was found incidentally during renal ultrasonography in a 14-year-old girl. Imaging studies showed a 13 × 9 × 15 cm homogeneous cystic lesion with mild contrast enhancement of the wall. The cyst appeared to originate from the retroperitoneum, but was separated from the left kidney, ovary, and pancreas. At laparotomy, there was a cyst behind the posterior peritoneum of the descending colon. The cyst was successfully excised, and histopathology showed MCA. Although primary MCA in the retroperitoneum is extremely rare in children, it should be considered in the differential diagnosis of an intra-abdominal cyst, since it needs to be excised to eliminate the risk of infection, recurrence, and malignancy.

  13. Frozen elephant trunk repair for descending thoracic aortic dissection in a man with a hostile left pleural cavity.

    Science.gov (United States)

    Kent, William D T; Manjunath, Adarsh; Malaisrie, S Chris

    2014-06-01

    The frozen elephant trunk procedure is a hybrid, single-staged alternative to conventional surgery for repairing diffuse pathologic conditions of the thoracic aorta. This approach is particularly advantageous in patients who have pathologic conditions of the left side of the chest, because the descending thoracic aorta can be repaired without entering a hostile pleural cavity. We present the case of a 67-year-old man who had undergone repair of acute type A aortic dissection. He presented with aneurysmal dilation of the descending thoracic aorta secondary to chronic dissection, a large acute dissection of the proximal ascending aorta, and a large paraesophageal hernia that made him a poor candidate for conventional, 2-staged open aortic repair. We describe the hybrid frozen elephant trunk technique that we used to repair the aorta, and its broader advantages.

  14. Tinbergen on mirror neurons

    OpenAIRE

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology—the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that ...

  15. Acute Type II Aortic Dissection with Severe Aortic Regurgitation and Chronic Descending Aortic Dissection in Pregnant Patient with Marfan Syndrome

    OpenAIRE

    Lee, Seok-Soo; Jung, Tae-Eun; Lee, Dong Hyup

    2012-01-01

    Aortic dilatation and dissection are severe complications during pregnancy that can be fatal to both the mother and the fetus. The risks of these complications are especially high in pregnant patients with Marfan syndrome; however, incidents of descending aortic dissection are very rare. This case report involves a successful Bentall procedure for and recovery from a rare aortic dissection in a pregnant Marfan patient who developed acute type II aortic dissection with severe aortic regurgitat...

  16. Avsenik in Buenos Aires: Transnational identification processes through polka performances among the descendants of Slovenian political exiles in Argentina

    OpenAIRE

    Molek, Nadia

    2017-01-01

    This paper discusses the transnational music practices and political reinforcement of national identities. It presents preliminary results of a research in progress about transnational cultural practices among the younger generations of Slovenian political exiles’ descendants in Argentina. It will explore the case of Baires Polka, a Slovenian Alpine Style music band that mainly performs cover versions of the Slovenian Avsenik Ensemble, as the basis for the analysis of the ways in which descen...

  17. Subjective perceptions associated with the ascending and descending slopes of breath alcohol exposure vary with recent drinking history.

    Science.gov (United States)

    Wetherill, Leah; Morzorati, Sandra L; Foroud, Tatiana; Windisch, Kyle; Darlington, Todd; Zimmerman, Ulrich S; Plawecki, Martin H; O'Connor, Sean J

    2012-06-01

    The differentiator model predicts that individuals with a positive family history of alcoholism (FHA) or heavy alcohol consumers will feel more sensitive to the effects of alcohol on the ascending phase of the blood alcohol content while feeling less sedated on the descending phase. This study tested whether subjective perceptions are sensitive to the slope of breath alcohol concentration (BrAC) and whether that sensitivity is associated with an FHA and/or recent drinking history (RDH). Family-history-positive (FHP, n = 27) and family-history-negative (FHN, n = 27) young adult nondependent drinkers were infused intravenously with alcohol in 2 sessions separated by 1 week. After 20 minutes, one session had an ascending BrAC (+3.0 mg%/min), while the other session had a descending BrAC (-1 mg%/min). The BrAC for both sessions at this point was approximately 60 mg%, referred to as the crossover point. Subjective perceptions of intoxication, high, stimulated, and sedation were sampled frequently and then interpolated to the crossover point. Within-subject differences between ascending and descending responses were examined for associations with FHA and/or RDH. Recent moderate drinkers reported increased perceptions of feeling intoxicated (p Subjective perceptions in young adult social drinkers depend on the slope of the BrAC when examined in association with RDH. These results support the differentiator model hypothesis concerning the ascending slope and suggest that moderate alcohol consumers could be at risk for increased alcohol consumption because they feel more intoxicated and high on the ascending slope. Subjects did not feel less sedated on the descending slope, contrary to the differentiator model but replicating several previous studies. Copyright © 2011 by the Research Society on Alcoholism.

  18. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster

    OpenAIRE

    Danjon, Frédéric; Caplan, Joshua S.; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account ...

  19. Blueberries and neuronal aging.

    Science.gov (United States)

    Shukitt-Hale, Barbara

    2012-01-01

    As the population of people in the United States over the age of 65 years continues to increase, so too will the incidence of age-related pathologies, including decreases in cognitive and motor function. In cases of severe deficits in memory or motor function, hospitalization and/or custodial care would be a likely outcome. This means that unless some way is found to reduce these age-related decrements in neuronal function, health care costs will continue to rise exponentially. Evidence is accumulating that consumption of blueberries may be one strategy to forestall or even reverse age-related neuronal deficits, as well as their subsequent behavioral manifestations, in order to increase healthy aging. Research suggests that the polyphenolic compounds found in blueberries exert their beneficial effects either through their ability to lower oxidative stress and inflammation or directly by altering the signaling involved in neuronal communication. These interventions, in turn, may protect against age-related deficits in cognitive and motor function. Appropriately, the US Department of Agriculture has figured prominently in these discoveries, through the efforts of two USDA researchers who worked for the department 100 years apart. Copyright © 2012 S. Karger AG, Basel.

  20. Uses of medicinal plants by Haitian immigrants and their descendants in the Province of Camagüey, Cuba

    Science.gov (United States)

    Volpato, Gabriele; Godínez, Daimy; Beyra, Angela; Barreto, Adelaida

    2009-01-01

    Background Haitian migrants played an important role shaping Cuban culture and traditional ethnobotanical knowledge. An ethnobotanical investigation was conducted to collect information on medicinal plant use by Haitian immigrants and their descendants in the Province of Camagüey, Cuba. Methods Information was obtained from semi-structured interviews with Haitian immigrants and their descendants, direct observations, and by reviewing reports of traditional Haitian medicine in the literature. Results Informants reported using 123 plant species belonging to 112 genera in 63 families. Haitian immigrants and their descendants mainly decoct or infuse aerial parts and ingest them, but medicinal baths are also relevant. Some 22 herbal mixtures are reported, including formulas for a preparation obtained using the fruit of Crescentia cujete. Cultural aspects related to traditional plant posology are addressed, as well as changes and adaptation of Haitian medicinal knowledge with emigration and integration over time. Conclusion The rapid disappearance of Haitian migrants' traditional culture due to integration and urbanization suggests that unrecorded ethnomedicinal information may be lost forever. Given this, as well as the poor availability of ethnobotanical data relating to traditional Haitian medicine, there is an urgent need to record this knowledge. PMID:19450279

  1. Spastic diparetic does not directly affect the capacity to ascend and descend access ramps: three-dimensional analysis

    Directory of Open Access Journals (Sweden)

    Tainá Ribas Mélo

    Full Text Available Abstract Introduction: Diplegic children have difficulties in gait and therefore ramps are used as strategies of accessibility. Objective: The present study investigated the influence of an inclined surface (ascending and descending on the kinematic characteristics during gait of the diplegic group (DG when compared to typically developing children of the control group (CG. Methods: Study participants included 20 children (10 with DG and 10 CG matched by age, which were evaluated in three experimental conditions (horizontal and inclined ascending and inclined descending surfaces of 7º through an optoelectronic imaging system. Results: Among the linear kinematic variables, only step width differed among groups, however, without influence of the surface. The foot height differed among the groups only in the descending phase, where DG had greater difficulty in raising the foot. The 3-dimensional gait analyses could not provide more evidences of differences in kinematics variables, especially in transverse plane, between DG and CG, but provide some evidence to support that hip range of motion (ROM during the gait cycle, hip flexion-extension in initial contact, knee ROM and the 2nd anterior-posterior trunk peak amplitude of the DG were influenced on descent by their flexor pattern. Conclusion: The DG was most affected by the inclination plane than CG especially on descent. Although a hip and knee flexor pattern is evident for DG on inclination of 7º, this angle is accessible since it allows independent gait functional activity.

  2. Hereditary position of kins in the first descending line of kinship, of the spouses and cohabitation partner: Comparative legal analysis

    Directory of Open Access Journals (Sweden)

    Vidić Jelena

    2011-01-01

    Full Text Available This paper analyses hereditary position of descendants, a surviving spouse and cohabitation partner, as heirs of the first class in intestate succession, in the law of Serbia and other modern laws of Europe. Through comparative legal analysis we point out both the similarities and differences, as well as the tendencies, that can be discerned in laws of Europe, regarding the manner in which the relationship between kinship, in the lineal descending line on one side and marriage, that is concubinage, on the other side, as legally relevant facts in creating the rules of intestacy, is established. In this way we aim to answer the question, to what extent is the relationship between the kinship in the lineal descending line and marriage in the law of Serbia synchronized with legal standards present in legal systems of the most European countries; and whether there is possibly a need for certain inheritance law reforms in the law of Serbia. Besides that, taking into account the fact that Serbian law belongs to the circle of legislations which give no merit to the fact of cohabitation when it comes to intestacy, this paper considers the justification of the need to legally regulate the inheritance of cohabitation partners in our law.

  3. Emergency treatment of acute rupture of the descending thoracic aorta using endovascular stent-grafts.

    Science.gov (United States)

    Amabile, Philippe; Rollet, Gilles; Vidal, Vincent; Collart, Frédéric; Bartoli, Jean-Michel; Piquet, Philippe

    2006-11-01

    Open surgical management of acute rupture of the descending thoracic aorta (DTA) is associated with high mortality and morbidity. Endovascular stent-grafts (ESGs) could provide a less invasive treatment alternative to conventional open surgery. The purpose of this report detailing our experience using ESG for treatment of acute rupture of the DTA is to determine the indications for endovascular repair. From June 2000 to April 2005, 17 patients presenting rupture of the DTA were treated using commercially available ESGs at our institution. There were two women and 15 men, with a mean age of 41.9 +/- 20.5 years. The cause of aortic rupture was traumatic in 13 cases and nontraumatic in four. Treatment was undertaken immediately in 10 cases and delayed in seven (range 5-68 days, mean 23.5). In one patient, the proximal neck landing zone was prepared prior to endovascular repair. No patients died during the postoperative period. The technical success rate was 84%. One patient developed a proximal type 1 endoleak at the end of the procedure. Three complications, i.e., two iliac dissections and one femoral artery rupture, occurred during the procedure. No paraplegia was observed. Mean follow-up was 13.3 months (range 1-41). One patient treated for traumatic rupture was lost from follow-up 21 months after initial treatment. No procedure-related complication was observed in this traumatic rupture group. Control computed tomographic scan at 13 months following the procedure demonstrated no evidence of periprosthetic leak or false aneurysm. In the nontraumatic rupture group, two patients died of aortic rupture and one treated for aortobronchial fistula developed recurrent hemoptysis 23 months after initial treatment and required placement of two additional ESGs. The immediate outcome of covered stent-graft placement for management of acute aortic rupture of the DTA is good. However, long-term surveillance is mandatory, especially in patients treated for nontraumatic aortic

  4. Results of the Valiant Mona LSA early feasibility study for descending thoracic aneurysms.

    Science.gov (United States)

    Roselli, Eric E; Arko, Frank R; Thompson, Matthew M

    2015-12-01

    Stent graft coverage of the left subclavian artery (LSA) may be required to achieve an adequate landing zone in up to 40% of descending thoracic aneurysms (DTAs). The Valiant Mona LSA Thoracic Stent Graft System (Medtronic, Santa Rosa, Calif) consists of a main stent graft and a branch stent graft designed to maintain LSA patency while diverting circulation through the encroaching aneurysm. Participating in the United States Food and Drug Administration's new Innovation Pathway, this first-in-human, early feasibility study evaluates early clinical experience of the Valiant Mona LSA Stent Graft System in patients with DTAs where the proximal landing zone necessitates LSA coverage. This premarket, nonrandomized, single-arm prospective study recruited nine patients (age 72.9 ± 7.6 years). Primary end points were aneurysm-related mortality, stroke, paraplegia, left arm/hand ischemia, and treatment success. Neurologic events were assessed by imaging and by independent neurologists. Inclusion criteria required patients with a DTA or penetrating aortic ulcer to have a distance of ≥10 mm between the left common carotid artery and the LSA. Mean aneurysm diameter was 53.7 ± 10.0 mm. The indication for repair was for saccular DTA in five patients or fusiform DTA in four. Seven patients were at American Society of Anesthesiologists Physical Status Classification III/IV. All nine patients received one main stent graft (diameter 28 to 42 mm) and one branch stent graft (diameter 10 to 14 mm). To extend device coverage distally, a commercial Valiant Captivia device was implanted in seven patients. No uncorrected endoleaks were observed at the end of the implant procedure. Four endoleaks developed before discharge in four of eight evaluable patients. Two were identified as type II and two were of undetermined type. No endoleak resulted in a secondary intervention. Technical success, defined by the clinical investigational plan, was achieved in all nine patients intraoperatively

  5. An attempt to detect reflected waves from the lower boundary of a descending slab

    Science.gov (United States)

    Hiyoshi, Takahiro; Yoshioka, Shoichi

    1997-12-01

    We attempted to detect reflected waves from deep-focus earthquakes at the lower boundary of a descending slab. For this purpose, we calculated theoretical waveforms in the realistic heterogeneous velocity and Q structures beneath the Japanese islands, and compared them with seismic waveforms observed in the Kanto-Tokai districts of central Japan. Assuming that earthquakes occur within the deeper portion of the slab, we investigated the effects of variation in focal mechanisms, focal depths, velocity contrasts near the lower plate boundary, and the Q structures on theoretical seismograms on the earth's surface. The results show that the amplitudes of the P to P and S to S reflected waves gradually increase toward the subduction zone, and take maximum values near the trench axis. However, travel time difference between the direct wave and the following reflected wave decreases there, making it difficult to detect the reflected wave. Based on these theoretical calculations, we investigated digital three-component seismograms observed in the Kanto-Tokai districts by the National Research Institute for Earth Science and Disaster Prevention, Science and Technology Agency (NIED). The seismograms observed were obtained from deep-focus earthquakes, from 1990 through 1996, with magnitude of 5.0 and greater. After carefully checking seismograms from 15 deep-focus events, we could not detect the reflected waves from the lower plate boundary systematically at expected arrival times from the theoretical calculation. This indicates that the reflected waves are either masked by coda waves followed by the direct P and S waves or below the noise level that is detectable by seismometers. There is also a possibility that the seismic velocity contrast between the slab and the underlying upper mantle may not be so sharp. However, the possibility to detect the S to S reflected waves increases if we check observed waveforms in the horizontal range between 200 to 300 km landward from

  6. Physiologic capacity of well-developed collaterals in patients with isolated left anterior descending artery disease

    International Nuclear Information System (INIS)

    Sakata, Kazuyuki; Yoshida, Hiroshi; Ono, Norihisa; Ohtani, Seiji; Mori, Noriko; Yokoyama, Shoichi; Hoshino, Tsuneo; Kaburagi, Tsuneo; Kurata, Chinori.

    1992-01-01

    To assess the physiologic significance of well-developed collaterals, 34 patients, with isolated left anterior descending artery disease (LAD) and without overt prior myocardial infarction, underwent cardiac catheterization and exercise thallium-201 emission computed tomography. The patients were divided into 3 groups: 11 patients with 90% stenosis of the proximal LAD and without collaterals (group 1), 11 with 99% stenosis of the proximal LAD, and without collaterals (group 2) and 12 with a total occlusion of the proximal LAD which was completely filled by well-developed collaterals (group 3). On left ventriculography, shortening fractions of the anterior wall were significantly reduced in group 2 as compared to groups 1 and 3 (group 1 vs group 2: p<0.01, group 2 vs group 3: p<0.05), which reflected the lower ejection fraction of group 2 (p<0.01 and p<0.05, respectively). The perfusion defects of the anterior wall on both the initial and the delayed images were severer in groups 2 and 3 than in group 1 (group 1 vs group 2 and group 1 vs group 3 on the initial image: p<0.01, for both, group 1 vs group 2 and group 1 vs group 3 on the delayed image: p<0.05, for both). However, recovery of the perfusion defects from the initial image to the delayed image was better in group 3 than in groups 1 and 2 (group 1 vs group 2 and group 1 vs group 3: p<0.05, for both). Therefore, coronary blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 90% stenosis at rest. During maximal exercise, blood flow through well-developed collaterals was considered to be comparable to the flow through a diseased vessel with 99% stenosis, although the blood flow through well-developed collaterals was considered to be better than that through 99% stenosis during the recovery period. These findings suggest that patients with well-developed collaterals must be treated like those with severe stenosis. (author)

  7. Electroacupuncture reduces the evoked responses of the spinal dorsal horn neurons in ankle-sprained rats

    Science.gov (United States)

    Kim, Jae Hyo; Kim, Hee Young; Chung, Kyungsoon

    2011-01-01

    Acupuncture is shown to be effective in producing analgesia in ankle sprain pain in humans and animals. To examine the underlying mechanisms of the acupuncture-induced analgesia, the effects of electroacupuncture (EA) on weight-bearing forces (WBR) of the affected foot and dorsal horn neuron activities were examined in a rat model of ankle sprain. Ankle sprain was induced manually by overextending ligaments of the left ankle in the rat. Dorsal horn neuron responses to ankle movements or compression were recorded from the lumbar spinal cord using an in vivo extracellular single unit recording setup 1 day after ankle sprain. EA was applied to the SI-6 acupoint on the right forelimb (contralateral to the sprained ankle) by trains of electrical pulses (10 Hz, 1-ms pulse width, 2-mA intensity) for 30 min. After EA, WBR of the sprained foot significantly recovered and dorsal horn neuron activities were significantly suppressed in ankle-sprained rats. However, EA produced no effect in normal rats. The inhibitory effect of EA on hyperactivities of dorsal horn neurons of ankle-sprained rats was blocked by the α-adrenoceptor antagonist phentolamine (5 mg/kg ip) but not by the opioid receptor antagonist naltrexone (10 mg/kg ip). These data suggest that EA-induced analgesia in ankle sprain pain is mediated mainly by suppressing dorsal horn neuron activities through α-adrenergic descending inhibitory systems at the spinal level. PMID:21389301

  8. Serotonin Promotes Development and Regeneration of Spinal Motor Neurons in Zebrafish.

    Science.gov (United States)

    Barreiro-Iglesias, Antón; Mysiak, Karolina S; Scott, Angela L; Reimer, Michell M; Yang, Yujie; Becker, Catherina G; Becker, Thomas

    2015-11-03

    In contrast to mammals, zebrafish regenerate spinal motor neurons. During regeneration, developmental signals are re-deployed. Here, we show that, during development, diffuse serotonin promotes spinal motor neuron generation from pMN progenitor cells, leaving interneuron numbers unchanged. Pharmacological manipulations and receptor knockdown indicate that serotonin acts at least in part via 5-HT1A receptors. In adults, serotonin is supplied to the spinal cord mainly (90%) by descending axons from the brain. After a spinal lesion, serotonergic axons degenerate caudal to the lesion but sprout rostral to it. Toxin-mediated ablation of serotonergic axons also rostral to the lesion impaired regeneration of motor neurons only there. Conversely, intraperitoneal serotonin injections doubled numbers of new motor neurons and proliferating pMN-like progenitors caudal to the lesion. Regeneration of spinal-intrinsic serotonergic interneurons was unaltered by these manipulations. Hence, serotonin selectively promotes the development and adult regeneration of motor neurons in zebrafish. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  9. Parvalbumin+ Neurons and Npas1+ Neurons Are Distinct Neuron Classes in the Mouse External Globus Pallidus.

    Science.gov (United States)

    Hernández, Vivian M; Hegeman, Daniel J; Cui, Qiaoling; Kelver, Daniel A; Fiske, Michael P; Glajch, Kelly E; Pitt, Jason E; Huang, Tina Y; Justice, Nicholas J; Chan, C Savio

    2015-08-26

    Compelling evidence suggests that pathological activity of the external globus pallidus (GPe), a nucleus in the basal ganglia, contributes to the motor symptoms of a variety of movement disorders such as Parkinson's disease. Recent studies have challenged the idea that the GPe comprises a single, homogenous population of neurons that serves as a simple relay in the indirect pathway. However, we still lack a full understanding of the diversity of the neurons that make up the GPe. Specifically, a more precise classification scheme is needed to better describe the fundamental biology and function of different GPe neuron classes. To this end, we generated a novel multicistronic BAC (bacterial artificial chromosome) transgenic mouse line under the regulatory elements of the Npas1 gene. Using a combinatorial transgenic and immunohistochemical approach, we discovered that parvalbumin-expressing neurons and Npas1-expressing neurons in the GPe represent two nonoverlapping cell classes, amounting to 55% and 27% of the total GPe neuron population, respectively. These two genetically identified cell classes projected primarily to the subthalamic nucleus and to the striatum, respectively. Additionally, parvalbumin-expressing neurons and Npas1-expressing neurons were distinct in their autonomous and driven firing characteristics, their expression of intrinsic ion conductances, and their responsiveness to chronic 6-hydroxydopamine lesion. In summary, our data argue that parvalbumin-expressing neurons and Npas1-expressing neurons are two distinct functional classes of GPe neurons. This work revises our understanding of the GPe, and provides the foundation for future studies of its function and dysfunction. Until recently, the heterogeneity of the constituent neurons within the external globus pallidus (GPe) was not fully appreciated. We addressed this knowledge gap by discovering two principal GPe neuron classes, which were identified by their nonoverlapping expression of the

  10. Astroglial networks promote neuronal coordination.

    Science.gov (United States)

    Chever, Oana; Dossi, Elena; Pannasch, Ulrike; Derangeon, Mickael; Rouach, Nathalie

    2016-01-12

    Astrocytes interact with neurons to regulate network activity. Although the gap junction subunits connexin 30 and connexin 43 mediate the formation of extensive astroglial networks that cover large functional neuronal territories, their role in neuronal synchronization remains unknown. Using connexin 30- and connexin 43-deficient mice, we showed that astroglial networks promoted sustained population bursts in hippocampal slices by setting the basal active state of neurons. Astroglial networks limited excessive neuronal depolarization induced by spontaneous synaptic activity, increased neuronal release probability, and favored the recruitment of neurons during bursting, thus promoting the coordinated activation of neuronal networks. In vivo, this sustained neuronal coordination translated into increased severity of acutely evoked epileptiform events and convulsive behavior. These results revealed that connexin-mediated astroglial networks synchronize bursting of neuronal assemblies, which can exacerbate pathological network activity and associated behavior. Our data thus provide molecular and biophysical evidence predicting selective astroglial gap junction inhibitors as anticonvulsive drugs. Copyright © 2016, American Association for the Advancement of Science.

  11. Expiratory muscle control during vomiting - Role of brain stem expiratory neurons

    Science.gov (United States)

    Miller, A. D.; Tan, L. K.

    1987-01-01

    The neural mechanisms controlling the muscles involved during vomiting were examined using decerebrated cats. In one experiment, the activity of the ventral respiratory group (VRG) expiratory (E) neurons was recorded during induced 'fictive vomiting' (i.e., a series of bursts of coactivation of abdominal and phrenic nerves that would be expected to produce expulsion in unparalyzed animals) and vomiting. In a second, abdominal muscle electromyographic and nerve activity were compared before and after sectioning the axons of descending VRG E neurons as they cross the midline between C1 and the obex (the procedure that is known to abolish expiratory modulation of internal intercostal muscle activity). The results of the study indicate that the abdominal muscles are controlled differently during respiration and vomiting.

  12. Persistent inflammation-induced up-regulation of brain-derived neurotrophic factor (BDNF) promotes synaptic delivery of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor GluA1 subunits in descending pain modulatory circuits.

    Science.gov (United States)

    Tao, Wenjuan; Chen, Quan; Zhou, Wenjie; Wang, Yunping; Wang, Lu; Zhang, Zhi

    2014-08-08

    The enhanced AMPA receptor phosphorylation at GluA1 serine 831 sites in the central pain-modulating system plays a pivotal role in descending pain facilitation after inflammation, but the underlying mechanisms remain unclear. We show here that, in the rat brain stem, in the nucleus raphe magnus, which is a critical relay in the descending pain-modulating system of the brain, persistent inflammatory pain induced by complete Freund adjuvant (CFA) can enhance AMPA receptor-mediated excitatory postsynaptic currents and the GluA2-lacking AMPA receptor-mediated rectification index. Western blot analysis showed an increase in GluA1 phosphorylation at Ser-831 but not at Ser-845. This was accompanied by an increase in distribution of the synaptic GluA1 subunit. In parallel, the level of histone H3 acetylation at bdnf gene promoter regions was reduced significantly 3 days after CFA injection, as indicated by ChIP assays. This was correlated with an increase in BDNF mRNA levels and BDNF protein levels. Sequestering endogenous extracellular BDNF with TrkB-IgG in the nucleus raphe magnus decreased AMPA receptor-mediated synaptic transmission and GluA1 phosphorylation at Ser-831 3 days after CFA injection. Under the same conditions, blockade of TrkB receptor functions, phospholipase C, or PKC impaired GluA1 phosphorylation at Ser-831 and decreased excitatory postsynaptic currents mediated by GluA2-lacking AMPA receptors. Taken together, these results suggest that epigenetic up-regulation of BDNF by peripheral inflammation induces GluR1 phosphorylation at Ser-831 sites through activation of the phospholipase C-PKC signaling cascade, leading to the trafficking of GluA1 to pain-modulating neuronal synapses. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  13. From Neurons to Newtons

    DEFF Research Database (Denmark)

    Nielsen, Bjørn Gilbert

    2001-01-01

    proteins generate forces, to the macroscopic levels where overt arm movements are vol- untarily controlled within an unpredictable environment by legions of neurons¯ring in orderly fashion. An extensive computer simulation system has been developed for this thesis, which at present contains a neural...... of phenomena, ranging from the force-velocity and force-length relationships, to tetanic fusion, "catch-like" e®ects and the distinctions between fast and slow muscle ¯ber types. Furthermore the model incorporates su±cient neuromus-cular information as to permit orderly recruitment of motor units, exponential...

  14. Imitation, mirror neurons and autism

    OpenAIRE

    Williams, Justin H.G.; Whiten, Andrew; Suddendorf, Thomas; Perrett, David I.

    2001-01-01

    Various deficits in the cognitive functioning of people with autism have been documented in recent years but these provide only partial explanations for the condition. We focus instead on an imitative disturbance involving difficulties both in copying actions and in inhibiting more stereotyped mimicking, such as echolalia. A candidate for the neural basis of this disturbance may be found in a recently discovered class of neurons in frontal cortex, 'mirror neurons' (MNs). These neurons show ac...

  15. The biophysics of neuronal growth

    International Nuclear Information System (INIS)

    Franze, Kristian; Guck, Jochen

    2010-01-01

    For a long time, neuroscience has focused on biochemical, molecular biological and electrophysiological aspects of neuronal physiology and pathology. However, there is a growing body of evidence indicating the importance of physical stimuli for neuronal growth and development. In this review we briefly summarize the historical background of neurobiophysics and give an overview over the current understanding of neuronal growth from a physics perspective. We show how biophysics has so far contributed to a better understanding of neuronal growth and discuss current inconsistencies. Finally, we speculate how biophysics may contribute to the successful treatment of lesions to the central nervous system, which have been considered incurable until very recently.

  16. Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin.

    Science.gov (United States)

    Caudle, Robert M; Mannes, Andrew J; Keller, Jason; Perez, Federico M; Suckow, Shelby K; Neubert, John K

    2007-05-10

    Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA). This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing. The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB) and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 microg) injected intrathecally produce thermal hyperalgesia. At higher doses (10 microg) peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons. The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.

  17. Sensitization of spinal cord nociceptive neurons with a conjugate of substance P and cholera toxin

    Directory of Open Access Journals (Sweden)

    Perez Federico M

    2007-05-01

    Full Text Available Abstract Background Several investigators have coupled toxins to neuropeptides for the purpose of lesioning specific neurons in the central nervous system. By producing deficits in function these toxin conjugates have yielded valuable information about the role of these cells. In an effort to specifically stimulate cells rather than kill them we have conjugated the neuropeptide substance P to the catalytic subunit of cholera toxin (SP-CTA. This conjugate should be taken up selectively by neurokinin receptor expressing neurons resulting in enhanced adenylate cyclase activity and neuronal firing. Results The conjugate SP-CTA stimulates adenylate cyclase in cultured cells that are transfected with either the NK1 or NK2 receptor, but not the NK3 receptor. We further demonstrate that intrathecal injection of SP-CTA in rats induces the phosphorylation of the transcription factor cyclic AMP response element binding protein (CREB and also enhances the expression of the immediate early gene c-Fos. Behaviorally, low doses of SP-CTA (1 μg injected intrathecally produce thermal hyperalgesia. At higher doses (10 μg peripheral sensitivity is suppressed suggesting that descending inhibitory pathways may be activated by the SP-CTA induced sensitization of spinal cord neurons. Conclusion The finding that stimulation of adenylate cyclase in neurokinin receptor expressing neurons in the spinal cord produces thermal hyperalgesia is consistent with the known actions of these neurons. These data demonstrate that cholera toxin can be targeted to specific cell types by coupling the catalytic subunit to a peptide agonist for a g-protein coupled receptor. Furthermore, these results demonstrate that SP-CTA can be used as a tool to study sensitization of central neurons in vivo in the absence of an injury.

  18. Electroacupuncture Inhibits the Activation of p38MAPK in the Central Descending Facilitatory Pathway in Rats with Inflammatory Pain

    Directory of Open Access Journals (Sweden)

    Man-Li Hu

    2017-01-01

    Full Text Available The mitogen-activated protein kinases (MAPKs, especially p38MAPK, play a pivotal role in chronic pain. Electroacupuncture (EA relieves inflammatory pain underlying the descending pathway, that is, the periaqueductal gray (PAG, the rostral ventromedial medulla (RVM, and the spinal cord dorsal horn (SCDH. However, whether EA antagonizes inflammatory pain through regulation of p38MAPK in this descending facilitatory pathway is unclear. Complete Freund’s adjuvant (CFA was injected into the hind paw of rats to establish inflammatory pain model. EA was administrated for 30 min at Zusanli and Kunlun acupoints at 0.5, 24.5, 48.5, and 72.5 h, respectively. The paw withdrawal threshold (PWT, paw edema, and Phosphor-p38MAPK-Immunoreactivity (p-p38MAPK-IR cells were measured before (0 h and at 1, 3, 5, 7, 25, and 73 h after CFA or saline injection. EA increased PWT at 1, 3, 25, and 73 h and inhibited paw edema at 25 and 73 h after CFA injection. Moreover, the increasing number of p-p38MAPK-IR cells which was induced by CFA was suppressed by EA stimulation in PAG and RVM at 3 and 5 h and in SCDH at 5, 7, 25, and 73 h. These results suggest that EA suppresses inflammation-induced hyperalgesia probably through inhibiting p38MAPK activation in the descending facilitatory pathway.

  19. Rapid genome-wide evolution in Brassica rapa populations following drought revealed by sequencing of ancestral and descendant gene pools.

    Science.gov (United States)

    Franks, Steven J; Kane, Nolan C; O'Hara, Niamh B; Tittes, Silas; Rest, Joshua S

    2016-08-01

    There is increasing evidence that evolution can occur rapidly in response to selection. Recent advances in sequencing suggest the possibility of documenting genetic changes as they occur in populations, thus uncovering the genetic basis of evolution, particularly if samples are available from both before and after selection. Here, we had a unique opportunity to directly assess genetic changes in natural populations following an evolutionary response to a fluctuation in climate. We analysed genome-wide differences between ancestors and descendants of natural populations of Brassica rapa plants from two locations that rapidly evolved changes in multiple phenotypic traits, including flowering time, following a multiyear late-season drought in California. These ancestor-descendant comparisons revealed evolutionary shifts in allele frequencies in many genes. Some genes showing evolutionary shifts have functions related to drought stress and flowering time, consistent with an adaptive response to selection. Loci differentiated between ancestors and descendants (FST outliers) were generally different from those showing signatures of selection based on site frequency spectrum analysis (Tajima's D), indicating that the loci that evolved in response to the recent drought and those under historical selection were generally distinct. Very few genes showed similar evolutionary responses between two geographically distinct populations, suggesting independent genetic trajectories of evolution yielding parallel phenotypic changes. The results show that selection can result in rapid genome-wide evolutionary shifts in allele frequencies in natural populations, and highlight the usefulness of combining resurrection experiments in natural populations with genomics for studying the genetic basis of adaptive evolution. © 2016 The Authors. Molecular Ecology Published by John Wiley & Sons Ltd.

  20. Non-Anastomotic Rupture of a Woven Dacron Graft in the Descending Thoracic Aorta Treated with Endovascular Stent Grafting

    Directory of Open Access Journals (Sweden)

    Youngok Lee

    2016-12-01

    Full Text Available The intrinsic structural failure of a Dacron graft resulting from the loss of structural integrity of the graft fabric can cause late graft complications. Late non-anastomotic rupture has traditionally been treated surgically via open thoracotomy. We report a case of the successful use of thoracic endovascular repair to treat a Dacron graft rupture in the descending aorta. The rupture occurred 20 years after the graft had been placed. Two stent grafts were placed at the proximal portion of the surgical graft, covering almost its entire length.

  1. Development of an polarization sensitive Fourier domain optical coherence tomography and it utilization on the Mueller matrix determination; Desenvolvimento de um sistema de tomografia por coerencia optica no dominio de Fourier sensivel a polarizacao e sua utilizacao na determinacao das matrizes de Mueller

    Energy Technology Data Exchange (ETDEWEB)

    Raele, Marcus Paulo

    2009-07-01

    This study approached theoretical and experimental aspects related with the development of a polarization sensitive, Fourier domain, optical coherence tomography system (PS-FD-OCT) and its utilization on the Mueller Matrix determination. This work began with a bibliographic revision, which describes since the early studies to the actual state of the art of the technique. The mathematical formalism of Fourier domain low coherence interferometry and light polarization was performed as well. Studies based on numerical simulations, of three different algorithm types, responsible to recover the scattering profile, were done. The implemented algorithms were: Direct Fourier Transform, Interpolation and zero-filling. By the end of the simulation study, was possible to conclude that the algorithm zero-filling 2N presented better characteristics when compared with the others. In the experimental part, firstly different OCT setups were assembled and measurements were done in order to verify aspects related with the theory. Then, using a polymeric sample, birefringence images were performed, which allowed determining the sample birefringence quantitatively. Finally, images taken of different polarization states were collected, and through then images related with the Mueller Matrix elements were calculated, which were analyzed individually. (author)

  2. Motor neuron disease in blacks

    African Journals Online (AJOL)

    1989-08-19

    Aug 19, 1989 ... A series of 86 black, Indian and white patients with motor neuron disease were analysed retrospectively. Although the material does not allow statistically valid conclusions, there are sufficient cases among blacks to allow two prima facie observations in this population group: (~ motor neuron disease.

  3. The Neuronal Ceroid-Lipofuscinoses

    Science.gov (United States)

    Bennett, Michael J.; Rakheja, Dinesh

    2013-01-01

    The neuronal ceroid-lipofuscinoses (NCL's, Batten disease) represent a group of severe neurodegenerative diseases, which mostly present in childhood. The phenotypes are similar and include visual loss, seizures, loss of motor and cognitive function, and early death. At autopsy, there is massive neuronal loss with characteristic storage in…

  4. Understanding Neuronal Mechanisms of Epilepsy ...

    Indian Academy of Sciences (India)

    Admin

    20 μM glutamate,. Recording epileptogenesis. Long term connectivity c. 10 min neuronal loss. (De Lorenzo et al., 2000) injury epileptogenesis. Neuronal loss .... decay. Control Condition. Relative Increase in τ decay. Values in. Epileptic Condition. The relative contribution of the Na+/Ca2+ exchangers in Ca2+ extrusion.

  5. Orexin neurons receive glycinergic innervations.

    Directory of Open Access Journals (Sweden)

    Mari Hondo

    Full Text Available Glycine, a nonessential amino-acid that acts as an inhibitory neurotransmitter in the central nervous system, is currently used as a dietary supplement to improve the quality of sleep, but its mechanism of action is poorly understood. We confirmed the effects of glycine on sleep/wakefulness behavior in mice when administered peripherally. Glycine administration increased non-rapid eye movement (NREM sleep time and decreased the amount and mean episode duration of wakefulness when administered in the dark period. Since peripheral administration of glycine induced fragmentation of sleep/wakefulness states, which is a characteristic of orexin deficiency, we examined the effects of glycine on orexin neurons. The number of Fos-positive orexin neurons markedly decreased after intraperitoneal administration of glycine to mice. To examine whether glycine acts directly on orexin neurons, we examined the effects of glycine on orexin neurons by patch-clamp electrophysiology. Glycine directly induced hyperpolarization and cessation of firing of orexin neurons. These responses were inhibited by a specific glycine receptor antagonist, strychnine. Triple-labeling immunofluorescent analysis showed close apposition of glycine transporter 2 (GlyT2-immunoreactive glycinergic fibers onto orexin-immunoreactive neurons. Immunoelectron microscopic analysis revealed that GlyT2-immunoreactive terminals made symmetrical synaptic contacts with somata and dendrites of orexin neurons. Double-labeling immunoelectron microscopy demonstrated that glycine receptor alpha subunits were localized in the postsynaptic membrane of symmetrical inhibitory synapses on orexin neurons. Considering the importance of glycinergic regulation during REM sleep, our observations suggest that glycine injection might affect the activity of orexin neurons, and that glycinergic inhibition of orexin neurons might play a role in physiological sleep regulation.

  6. Polarization sensitive optical coherence tomography - a review [Invited

    NARCIS (Netherlands)

    de Boer, Johannes F.; Hitzenberger, Christoph K.; Yasuno, Yoshiaki

    2017-01-01

    Optical coherence tomography (OCT) is now a well-established modality for high-resolution cross-sectional and three-dimensional imaging of transparent and translucent samples and tissues. Conventional, intensity based OCT, however, does not provide a tissue-specific contrast, causing an ambiguity

  7. Altered control strategy between leading and trailing leg increases knee adduction moment in the elderly while descending stairs.

    Science.gov (United States)

    Karamanidis, Kiros; Arampatzis, Adamantios

    2011-02-24

    The aim of the study was to examine the external knee adduction moments in a group of older and younger adults while descending stairs and thus the possibility of an increased risk of knee osteoarthritis due to altered knee joint loading in the elderly. Twenty-seven older and 16 younger adults descended a purpose-built staircase. A motion capture system and a force plate were used to determine the subjects' 3D kinematics and ground reaction forces (GRF) during locomotion. Calculation of the leg kinematics and kinetics was done by means of a rigid, three-segment, 3D leg model. In the initial portion of the support phase, older adults showed a more medio-posterior GRF vector relative to the ankle joint, leading to lower ankle joint moments (Pelderly (Pcontrol strategy while stepping down is a more medially directed GRF vector increasing the magnitude of external knee adduction moment in the elderly. The observed changes between leading and trailing leg in the elderly may cause a redistribution of the mechanical load at the tibiofemoral joint, affecting the initiation and progression of knee osteoarthritis in the elderly. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Mixed-source reintroductions lead to outbreeding depression in second-generation descendents of a native North American fish

    Science.gov (United States)

    Huff, D.D.; Miller, L.M.; Chizinski, C.J.; Vondracek, B.

    2011-01-01

    Reintroductions are commonly employed to preserve intraspecific biodiversity in fragmented landscapes. However, reintroduced populations are frequently smaller and more geographically isolated than native populations. Mixing genetically, divergent sources are often proposed to attenuate potentially low genetic diversity in reintroduced populations that may result from small effective population sizes. However, a possible negative tradeoff for mixing sources is outbreeding depression in hybrid offspring. We examined the consequences of mixed-source reintroductions on several fitness surrogates at nine slimy sculpin (Cottus cognatus) reintroduction sites in south-east Minnesota. We inferred the relative fitness of each crosstype in the reintroduced populations by comparing their growth rate, length, weight, body condition and persistence in reintroduced populations. Pure strain descendents from a single source population persisted in a greater proportion than expected in the reintroduced populations, whereas all other crosstypes occurred in a lesser proportion. Length, weight and growth rate were lower for second-generation intra-population hybrid descendents than for pure strain and first-generation hybrids. In the predominant pure strain, young-of the-year size was significantly greater than any other crosstype. Our results suggested that differences in fitness surrogates among crosstypes were consistent with disrupted co-adapted gene complexes associated with beneficial adaptations in these reintroduced populations. Future reintroductions may be improved by evaluating the potential for local adaptation in source populations or by avoiding the use of mixed sources by default when information on local adaptations or other genetic characteristics is lacking. ?? 2011 Blackwell Publishing Ltd.

  9. Daytime descending intermediate layers observed over a sub-tropical Indian station Waltair during low-solar activity period

    Directory of Open Access Journals (Sweden)

    K. Niranjan

    2010-03-01

    Full Text Available Study on daytime descending intermediate layer over subtropical Indian station Waltair (17.7° N, 83.3° E geographic, 6.4° N, 10° E geomagnetic, 20° N dip located in the equatorial anomaly transition region, using an IPS 42 Digital Ionosonde during the low solar activity year 2004 showed that the layers occur in the altitude range of 140–160 km with maximum occurrence during winter solstice. The layers observed during daytime occur with a double peak variation throughout the year with less occurrence probability and shorter duration presence during forenoon hours. The morning layer descent was associated with a density increase where as during afternoon hours a decrease in density was observed. The downward drift velocity was about 8 km/h during morning hours and between 7–11 km/h during afternoon hours, with a low descent rate of around 4.5 km/h during summer morning hours. The results indicate the presence of a 6 h tide at this location as observed from the characteristics of the descending layers, unlike at majority of locations where a significant semi diurnal trend is observed. The study brings out the complex nature of the tidal interaction at different locations.

  10. Free-flap cover of complex defects around the knee using the descending genicular artery as the recipient pedicle.

    Science.gov (United States)

    Venkatramani, H; Sabapathy, S R; Nayak, S

    2014-01-01

    Selection of ideal recipient vessels is one of the most important factors determining success in free-flap reconstruction of the lower limb. At the knee, the choice of vessels has traditionally been either the common femoral or the popliteal vessels and their branches but these are often difficult to use or cannot be used. A series of 32 free flaps for cover of complex injuries of the knee involving the distal femur, the knee joint and the upper tibia were reconstructed using the descending genicular branch of the femoral artery in the adductor canal and its muscular branches to the vastus medialis as the recipient vessels. All but one flap survived with no major complications. The use of the descending genicular artery as the recipient vessel for reconstruction with free flaps around the knee has various advantages including: (i) it is mostly remote from the zone of trauma, (ii) it is constant in location, (iii) the recipient vessels are an excellent size match for end-to-end anastomosis, (iv) there is no need for changes of position of the patient when using most free flaps commonly used for knee reconstruction, (v) it is easy to harvest these simultaneously, (vi) secondary exposure of the underlying skeleton from all quadrants is unlikely to divide the flap pedicle as it is superior and (vii), perhaps most important of all, it obviates the need for exploration of the popliteal fossa. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  11. Extended right hemicolectomy and left hemicolectomy for colorectal cancers between the distal transverse and proximal descending colon.

    Science.gov (United States)

    Gravante, G; Elshaer, M; Parker, R; Mogekwu, A C; Drake, B; Aboelkassem, A; Rahman, E U; Sorge, R; Alhammali, T; Gardiner, K; Al-Hamali, S; Rashed, M; Kelkar, A; Agarwal, R; El-Rabaa, S

    2016-05-01

    We report our experience with extended right hemicolectomy (ERH) and left hemicolectomy (LH) for the treatment of cancers located between the distal transverse and the proximal descending colon, and compare postoperative morbidity, mortality, pathological results and survival for the two techniques. A retrospective review was performed of a single institution series over ten years. Patients who underwent different operations, had benign disease or received palliative resections were excluded. Data collected were patient demographics, type and duration of surgery, tumour site, postoperative complications and histology results. Ninety-eight patients were analysed (64 ERHs, 34 LHs). ERH was conducted using an open approach in 93.8% of cases compared with 73.5% for LH. The anastomotic leak rate was similar for both groups (ERH: 6.3%, LH: 5.9%). This was also the case for other postoperative complications, mortality (ERH: 1.6%, LH: 2.9%) and overall survival (ERH: 50.4 months, LH: 51.8 months). All but one patient in the ERH cohort had clear surgical margins. Nodal evaluation for staging was adequate in 78.1% of ERH cases and 58.8% of LH cases. In our experience, both ERH and LH are adequate for tumours located between the distal transverse and the proximal descending colon.

  12. Age-related changes in skin color and histologic features of hairless descendants of Mexican hairless dogs.

    Science.gov (United States)

    Kimura, T; Doi, K

    1994-04-01

    Age-related changes in skin color and histologic features of hairless descendants of Mexican Hairless dogs were investigated and compared with those of haired descendants of Mexican Hairless dogs and Beagles. According to age, dogs studied were allotted to 4 groups: 0 to 2 weeks, 4 to 5 months, 1 to 1.5 years, and 3 to 4 years old. Skin color, histologic features, and numbers of dihydroxyphenylalanine (DOPA)-positive melanocytes were examined. The luminance values measured, using a spectrophotometer, decreased with advancing age up to 1.5 years, but they increased again at 3 to 4 years in hairless dogs. The number of DOPA-positive melanocytes in hairless dogs decreased with advancing age, whereas there were no DOPA-positive melanocytes in haired dogs and Beagles. Histologically, the epidermis of newborn hairless pups was thick. The border between the epidermis and dermis was wavy, and epidermal ingrowths were found projecting into the dermis. As hairless dogs grew older, the epidermis became thinner and flatter. Although numbers of hair follicles and sebaceous and apocrine sweat glands were apparently fewer in hairless dogs than in haired dogs and Beagles, these structures were detected at least up to 4 years of age. On the other hand, haired dogs and Beagles had a thin epidermis at birth and aging had little effect on their epidermal structures. The dermis of hairless dogs contained fewer mast cells than did that of haired dogs and Beagles.

  13. [Domains of physical activity in slave-descendant communities in Southwest Bahia State, Brazil: a population-based study].

    Science.gov (United States)

    Bezerra, Vanessa Moraes; Andrade, Amanda Cristina de Souza; César, Cibele Comini; Caiaffa, Waleska Teixeira

    2015-06-01

    This study aimed to describe the prevalence of physical activity (PA) and associated factors in various domains (leisure-time, work, home, and commuting) among quilombolas (descendants of African slaves) in Bahia State, Brazil. This was a cross-sectional study of 797 individuals from 18 to 100 years of age. The study adopted a cutoff point of 150 minutes of PA per week. A hierarchical Poisson model was used. The highest prevalence of PA was at work (42.1%), followed by the home environment (39.3%), commuting (35.5%), and leisure time (13.1%). PA at work was associated with male gender, lower age, higher schooling, and consumption of alcohol and fruits. PA in the household domain was associated with female gender, lower age, marital status (married), and negative self-rated health. In commuting, PA was associated with male gender and lower age bracket, and during leisure time with safety, male gender, lower age, and higher schooling. The study concludes that this slave-descendant community displays a profile of PA that is characteristic of rural groups (more active at work, with little leisure-time activity). The determinants of PA were similar to those seen in urban groups.

  14. A theoretical study of optimal methods for the determination of the activities of the descendants of radon

    International Nuclear Information System (INIS)

    Hartley, B.M.

    1990-01-01

    The accurate determiantion of the potential alpha energy of the descendants of radon relies on the determination of the individual number of atoms of those isotopes present. These are usually found by counting the particles emitted during radioactive decay of the individual atoms. By fitting the experimental count curve to the theoretical curve by a least squares method and using the number of atoms of the individual descendants present as the variable parameters, an optimal result can be obtained. Examination of the algorithm for generating the best fit indicates that it could be done in real time using microprocessors and gives the possibility of continuous evaluation of the number of atoms present and of the total potential alpha energy during counting. A comparison of ten different counting methods has been done theoretically using computer simulations of the count. For short counting times the method which can distinguish between each of the alpha particles and the beta particles is the most precise method available. It is shown that other methods of counting give comparable results when counting time is extended to over 2000 seconds. 4 refs., 1 tab., 2 figs

  15. Alleviating Bone Cancer-induced Mechanical Hypersensitivity by Inhibiting Neuronal Activity in the Anterior Cingulate Cortex.

    Science.gov (United States)

    Chiou, Chiuan-Shiou; Chen, Chien-Chung; Tsai, Tsung-Chih; Huang, Chiung-Chun; Chou, Dylan; Hsu, Kuei-Sen

    2016-10-01

    The anterior cingulate cortex (ACC) is a brain region that has been critically implicated in the processing of pain perception and modulation. While much evidence has pointed to an increased activity of the ACC under chronic pain states, less is known about whether pain can be alleviated by inhibiting ACC neuronal activity. The authors used pharmacologic, chemogenetic, and optogenetic approaches in concert with viral tracing technique to address this issue in a mouse model of bone cancer-induced mechanical hypersensitivity by intratibia implantation of osteolytic fibrosarcoma cells. Bilateral intra-ACC microinjections of γ-aminobutyric acid receptor type A receptor agonist muscimol decreased mechanical hypersensitivity in tumor-bearing mice (n =10). Using adenoviral-mediated expression of engineered Gi/o-coupled human M4 (hM4Di) receptors, we observed that activation of Gi/o-coupled human M4 receptors with clozapine-N-oxide reduced ACC neuronal activity and mechanical hypersensitivity in tumor-bearing mice (n = 11). In addition, unilateral optogenetic silencing of ACC excitatory neurons with halorhodopsin significantly decreased mechanical hypersensitivity in tumor-bearing mice (n = 4 to 9), and conversely, optogenetic activation of these neurons with channelrhodopsin-2 was sufficient to provoke mechanical hypersensitivity in sham-operated mice (n = 5 to 9). Furthermore, we found that excitatory neurons in the ACC send direct descending projections to the contralateral dorsal horn of the lumbar spinal cord via the dorsal corticospinal tract. The findings of this study indicate that enhanced neuronal activity in the ACC contributes to maintain bone cancer-induced mechanical hypersensitivity and suggest that the ACC may serve as a potential therapeutic target for treating bone cancer pain.

  16. Tinbergen on mirror neurons.

    Science.gov (United States)

    Heyes, Cecilia

    2014-01-01

    Fifty years ago, Niko Tinbergen defined the scope of behavioural biology with his four problems: causation, ontogeny, survival value and evolution. About 20 years ago, there was another highly significant development in behavioural biology-the discovery of mirror neurons (MNs). Here, I use Tinbergen's original four problems (rather than the list that appears in textbooks) to highlight the differences between two prominent accounts of MNs, the genetic and associative accounts; to suggest that the latter provides the defeasible 'best explanation' for current data on the causation and ontogeny of MNs; and to argue that functional analysis, of the kind that Tinbergen identified somewhat misleadingly with studies of 'survival value', should be a high priority for future research. In this kind of functional analysis, system-level theories would assign MNs a small, but potentially important, role in the achievement of action understanding-or another social cognitive function-by a production line of interacting component processes. These theories would be tested by experimental intervention in human and non-human animal samples with carefully documented and controlled developmental histories.

  17. Development of posterior hypothalamic neurons enlightens a switch in the prosencephalic basic plan.

    Directory of Open Access Journals (Sweden)

    Sophie Croizier

    Full Text Available In rats and mice, ascending and descending axons from neurons producing melanin-concentrating hormone (MCH reach the cerebral cortex and spinal cord. However, these ascending and descending projections originate from distinct sub-populations expressing or not "Cocaine-and-Amphetamine-Regulated-Transcript" (CART peptide. Using a BrdU approach, MCH cell bodies are among the very first generated in the hypothalamus, within a longitudinal cell cord made of earliest delaminating neuroblasts in the diencephalon and extending from the chiasmatic region to the ventral midbrain. This region also specifically expresses the regulatory genes Sonic hedgehog (Shh and Nkx2.2. First MCH axons run through the tractus postopticus (tpoc which gathers pioneer axons from the cell cord and courses parallel to the Shh/Nkx2.2 expression domain. Subsequently generated MCH neurons and ascending MCH axons differentiate while neurogenesis and mantle layer differentiation are generalized in the prosencephalon, including telencephalon. Ascending MCH axons follow dopaminergic axons of the mesotelencephalic tract, both being an initial component of the medial forebrain bundle (mfb. Netrin1 and Slit2 proteins that are involved in the establishment of the tpoc and mfb, respectively attract or repulse MCH axons.We conclude that first generated MCH neurons develop in a diencephalic segment of a longitudinal Shh/Nkx2.2 domain. This region can be seen as a prosencephalic segment of a medial neurogenic column extending from the chiasmatic region through the ventral neural tube. However, as the telencephalon expends, it exerts a trophic action and the mfb expands, inducing a switch in the longitudinal axial organization of the prosencephalon.

  18. DNA Damage Induced Neuronal Death

    National Research Council Canada - National Science Library

    Kisby, Glen

    1999-01-01

    ... (nitrogen mustard or HN2) and the neurotoxic DNA-damaging agent methylazoxymethanol (MAM) using neuronal and astrocyte cell cultures from different brain regions of mice with perturbed DNA repair...

  19. Information processing by neuronal populations

    National Research Council Canada - National Science Library

    Hölscher, Christian; Munk, Matthias

    2009-01-01

    ... simultaneously recorded spike trains 120 Mark Laubach, Nandakumar S. Narayanan, and Eyal Y. Kimchi Part III Neuronal population information coding and plasticity in specific brain areas 149 7 F...

  20. Trafficking of neuronal calcium channels

    Czech Academy of Sciences Publication Activity Database

    Weiss, Norbert; Zamponi, G. W.

    2017-01-01

    Roč. 1, č. 1 (2017), č. článku NS20160003. ISSN 2059-6553 R&D Projects: GA ČR GA15-13556S; GA MŠk 7AMB15FR015 Institutional support: RVO:61388963 Keywords : calcium channel * neuron * trafficing Subject RIV: ED - Physiology OBOR OECD: Physiology (including cytology) http://www. neuron alsignaling.org/content/1/1/NS20160003

  1. Model investigations 3D of gas-powder two phase flow in descending bed with consideration radial distribution of flow

    Directory of Open Access Journals (Sweden)

    B. Panic

    2013-04-01

    Full Text Available The results of experimental investigations concerning radial distribution of powder accumulation in bed and static pressure were presented in this paper. To realize this research physical model of gas-powder two phase flow with descending bed was projected and constructed. Amounts of “dynamic” and “static” powder accumulated in bed, in dependence on gas velocity and of bed particles were investigated. In 3D model “static” powder (with its radial distribution at the tuyere level and in the higher part of bed was measured. The influence of bed particles, powder and gas radial distribution on values of interaction forces between flow phases in investigated system was defined.

  2. Close Proximity of Left Anterior Descending Artery to the Right Ventricular Lead Apparently Implanted into the Mid-septum

    Directory of Open Access Journals (Sweden)

    Pavel Osmancik, MD, PhD, FESC, Petr Stros, MD

    2014-03-01

    Full Text Available Right ventricular (RV mid-septal pacing should have fewer negative effects on left ventricular function compared to apical pacing. However, targeting the mid-septum may be technically challenging since it is usually done with two-dimensional fluoroscopy. The rotation of the heart and various shapes of the RV make it difficult to assess, whether the lead is really anchored in the septum. Many leads, apparently anchored in the septum, are in fact anchored in the anterior wall or anteroseptal groove, and some can get anchored in close proximity to the left anterior descending artery (LAD. We report three cases from our series of 51 patients, in whom the RV lead thought to be implanted in the mid-septum was in fact anchored in close proximity of LAD when assessed using computed tomography.

  3. The Shadow of the Italian Colonial Experience: The Impact of Collective Emotions on Intentions to Help the Victims’ Descendants

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    Chiara Volpato

    2010-05-01

    Full Text Available Recalling the Italian colonial experience elicits the collective emotions of guilt, shame, and ingroup-focused anger. We expected that these emotions would predict different reparation intentions in favor of the colonized populations' descendants. Students and non-students were recruited (N = 152 and asked to rate their emotions of collective guilt, shame, and anger for the violence that their ingroup had perpetrated against colonized people. Results showed that shame affected intentions to provide economic compensation to current inhabitants of the ex-colonies. This relationship was mediated by concerns of damage for the ingroup's image. Anger toward the ingroup predicted intentions to help immigrants from the ex-colonies now living in Italy. Interestingly, empathy toward the outgroup mediated the latter relation. Finally, collective guilt was not reliably associated with any reparation strategy. These findings have implications for theory and for the historical collective memory of Italian colonialism.

  4. Mean blood velocities and flow impedance in the fetal descending thoracic aortic and common carotid artery in normal pregnancy.

    Science.gov (United States)

    Bilardo, C M; Campbell, S; Nicolaides, K H

    1988-12-01

    A linear array pulsed Doppler duplex scanner was used to establish reference ranges for mean blood velocities and flow impedance (Pulsatility Index = PI) in the descending thoracic aorta and in the common carotid artery from 70 fetuses in normal pregnancies at 17-42 weeks' gestation. The aortic velocity increased with gestation up to 32 weeks, then remained constant until term, when it decreased. In contrast, the velocity in the common carotid artery increased throughout pregnancy. The PI in the aorta remained constant throughout pregnancy, while in the common carotid artery it fell steeply after 32 weeks. These results suggest that with advancing gestation there is a redistribution of the fetal circulation with decreased impedance to flow to the fetal brain, presumably to compensate for the progressive decrease in fetal blood PO2.

  5. The genetic diversity of three peculiar populations descending from the slave trade: Gm study of Noir Marron from French Guiana.

    Science.gov (United States)

    Brucato, Nicolas; Tortevoye, Patricia; Plancoulaine, Sabine; Guitard, Evelyne; Sanchez-Mazas, Alicia; Larrouy, Georges; Gessain, Antoine; Dugoujon, Jean-Michel

    2009-10-01

    The Noir Marron communities are the direct descendants of African slaves brought to the Guianas during the four centuries (16th to 19th) of the Atlantic slave trade. Among them, three major ethnic groups have been studied: the Aluku, the Ndjuka and the Saramaka. Their history led them to share close relationships with Europeans and Amerindians, as largely documented in their cultural records. The study of Gm polymorphisms of immunoglobulins may help to estimate the amount of gene flow linked to these cultural exchanges. Surprisingly, very low levels of European contribution (2.6%) and Amerindian contribution (1.7%) are detected in the Noir Marron gene pool. On the other hand, an African contribution of 95.7% redraws their origin to West Africa (F(ST) < or = 0.15). This highly preserved African gene pool of the Noir Marron is unique in comparison to other African American populations of Latin America, who are notably more admixed.

  6. Axillary artery to left anterior descending coronary artery bypass with an externally stented graft: a technical report

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    Salvador Loris

    2008-02-01

    Full Text Available Abstract With the proliferation of minimally invasive cardiac surgery a number of alternative inflow sites for coronary artery bypass grafting have been utilized, especially in higher risk patients. The use of axillary-coronary artery bypass is a safe and effective alternative especially in the case of patients requiring redo coronary revascularization. However, the length and convoluted course of the axillary-coronary vein graft makes is susceptible to twisting, trauma and neointimal hyperplasia. We therefore report a case of an axillary-coronary artery bypass in a high risk patient in which a Dacron conduit was used to externally support and protect the vein graft to the left anterior descending artery. Surgical technique and considerations are presented and discussed.

  7. Detection of significant stenosis in the left anterior descending artery by 'virtual myocardial perfusion' bolus tracking, 320 slice computed tomography.

    Science.gov (United States)

    Takaoka, Hiroyuki; Funabashi, Nobusada; Fujimoto, Yoshihide; Kobayashi, Yoshio

    2014-12-20

    We used bolus-tracking CT-images, which are usually used only to detect contrast-material in target organs for optimal-starting of acquisition, as virtual first pass myocardial perfusion images. Retrospective-analysis of 14 patients (10 male, 63 ± 10 years) diagnosed with ≥ 75% stenosis confined to left-anterior-descending-artery (LAD) (7 patients, Group-1) or insignificant stenosis of any coronary artery (7 patients Group-2) diagnosed using invasive-coronary-angiograms (ICA) and enhanced 320-slice-CT within 3-months and without incident between examinations. Bolus-tracking CT-images were acquired at mid-level left-ventricle (LV) until CT-attenuation of descending-aorta increased to 200 HU. We measured CT-attenuation (HU) in the LV anterior-wall (AW), the basal inter-ventricular-septum (BIVS), and LV basal lateral-wall (BLW) in end-systole using both bolus-tracking images and routine, enhanced, early-phase CT-images. In the bolus-tracking images, the Group-1 LV AW, BIVS, BLW CT-attenuation and ratio of LV AW CT attenuation to the average of BIVS and BLW were 36 ± 7HU, 62 ± 11HU, 58 ± 25HU, and 0.6 ± 0.1 respectively. In Group-2, they were 53 ± 14HU, 56 ± 9HU, 54 ± 15HU, and 1.0 ± 0.3 respectively. LV AW CT attenuation and the ratio of LV AW CT values to the average of BIVS and BLW, were significantly lower in Group-1 (both P BLW and without the need for drugs, exercise or additional radiation-exposure. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  8. Human Cardiac-Derived Stem/Progenitor Cells Fine-Tune Monocyte-Derived Descendants Activities toward Cardiac Repair

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    Noémie Dam

    2017-10-01

    Full Text Available Cardiac repair following MI relies on a finely regulated immune response involving sequential recruitment of monocytes to the injured tissue. Monocyte-derived cells are also critical for tissue homeostasis and healing process. Our previous findings demonstrated the interaction of T and natural killer cells with allogeneic human cardiac-derived stem/progenitor cells (hCPC and suggested their beneficial effect in the context of cardiac repair. Therefore, we investigated here whether monocytes and their descendants could be also modulated by allogeneic hCPC toward a repair/anti-inflammatory phenotype. Through experimental in vitro assays, we assessed the impact of allogeneic hCPC on the recruitment, functions and differentiation of monocytes. We found that allogeneic hCPC at steady state or under inflammatory conditions can incite CCL-2/CCR2-dependent recruitment of circulating CD14+CD16− monocytes and fine-tune their activation toward an anti-inflammatory profile. Allogeneic hCPC also promoted CD14+CD16− monocyte polarization into anti-inflammatory/immune-regulatory macrophages with high phagocytic capacity and IL10 secretion. Moreover, hCPC bended the differentiation of CD14+CD16− monocytes to dendritic cells (DCs toward anti-inflammatory macrophage-like features and impaired their antigen-presenting function in favor of immune-modulation. Collectively, our results demonstrate that allogeneic hCPC could reshape monocytes, macrophages as well as DCs responses by favoring their anti-inflammatory/tolerogenic activation/polarization. Thereby, therapeutic allogeneic hCPC might also contribute to post-infarct myocardial healing by modeling the activities of monocytes and their derived descendants.

  9. Radiologic Placement of Uncovered Stents for the Treatment of Malignant Colonic Obstruction Proximal to the Descending Colon

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jehong; Kwon, Se Hwan, E-mail: Kwon98@khu.ac.kr [Kyung Hee University, Department of Radiology, College of Medicine (Korea, Republic of); Lee, Chang-Kyun [Kyung Hee University, Department of Internal Medicine, College of Medicine (Korea, Republic of); Park, Sun Jin [Kyung Hee University, Department of Surgery, College of Medicine (Korea, Republic of); Oh, Ji Young [Kyung Hee University Hospital at Gangdong, Department of Radiology (Korea, Republic of); Oh, Joo Hyeong [Kyung Hee University, Department of Radiology, College of Medicine (Korea, Republic of)

    2017-01-15

    PurposeTo evaluate the safety, feasibility, and patency rates of radiologic placement of uncovered stents for the treatment of malignant colonic obstruction proximal to the descending colon.Materials and MethodsThis was a retrospective, single-center study. From May 2003 to March 2015, 53 image-guided placements of uncovered stents (44 initial placements, 9 secondary placements) were attempted in 44 patients (male:female = 23:21; mean age, 71.8 years). The technical and clinical success, complication rates, and patency rates of the stents were also evaluated. Technical success was defined as the successful deployment of the stent under fluoroscopic guidance alone and clinical success was defined as the relief of obstructive symptoms or signs within 48 h of stent deployment.ResultsIn total, 12 (27.3 %) patients underwent preoperative decompression, while 32 (72.7 %) underwent decompression with palliative intent. The technical success rate was 93.2 % (41/44) for initial placement and 88.9 % (8/9) for secondary placement. Secondary stent placement in the palliative group was required in nine patients after successful initial stent placement due to stent obstruction from tumor ingrowth (n = 7) and stent migration (n = 2). The symptoms of obstruction were relieved in all successful cases (100 %). In the palliative group, the patency rates were 94.4 % at 1 month, 84.0 % at 3 months, 64.8 % at 6 months, and 48.6 % at 12 months.ConclusionsThe radiologic placement of uncovered stents for the treatment of malignant obstruction proximal to the descending colon is feasible and safe, and provides acceptable clinical results.

  10. Metastatic Small Bowel Tumor from Descending Colon Cancer with Extensive Hematogenous or Lymphogenous Spread: Survey of the Japanese Literature

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    Yutaka Kojima

    2010-09-01

    Full Text Available We present the case of a 68-year-old female patient who was diagnosed with cancer of the descending colon in July 1994 and underwent partial resection of the colon (type 2, moderately to well differentiated adenocarcinoma, se, ly1, v1, n(–. In April 1996, she was admitted to a nearby hospital for symptoms of ileus, which improved at the hospital. However, she was referred to our hospital for melena. In blood test, Hb was 8.7 g/dl, showing anemia, and carcinoembryonic antigen level was elevated to 50.7 ng/ml. Abdominal CT and small bowel series showed only mild expansion of the small bowel, suggesting no obvious occlusion. Abdominal surgery was performed in May 1995 for repeated development of ileus symptoms and suspicion of bleeding from the small bowel. Since the findings of the abdominal surgery showed a circular tumor in the lower ileum, partial resection of the small bowel was performed. Histopathological examination showed type 3, moderately to well differentiated adnocarcinoma, se, ly2, v0, n = 1/13. The principal tumor was located within the subserosa and grew up exclusively through the muscularis propria and the submucosa, into the mucous layer. The mucosa remained slightly on the surface layer. Based on these findings, the patient was diagnosed with metastasis of descending colon cancer to the small bowel. Her prognosis was good, and neither metastasis nor redevelopment of the cancer have been confirmed to date, 11 years and 7 months since the surgery.

  11. The View from the Trees: Nocturnal Bull Ants, Myrmecia midas, Use the Surrounding Panorama While Descending from Trees

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    Cody A. Freas

    2018-01-01

    Full Text Available Solitary foraging ants commonly use visual cues from their environment for navigation. Foragers are known to store visual scenes from the surrounding panorama for later guidance to known resources and to return successfully back to the nest. Several ant species travel not only on the ground, but also climb trees to locate resources. The navigational information that guides animals back home during their descent, while their body is perpendicular to the ground, is largely unknown. Here, we investigate in a nocturnal ant, Myrmecia midas, whether foragers travelling down a tree use visual information to return home. These ants establish nests at the base of a tree on which they forage and in addition, they also forage on nearby trees. We collected foragers and placed them on the trunk of the nest tree or a foraging tree in multiple compass directions. Regardless of the displacement location, upon release ants immediately moved to the side of the trunk facing the nest during their descent. When ants were released on non-foraging trees near the nest, displaced foragers again travelled around the tree to the side facing the nest. All the displaced foragers reached the correct side of the tree well before reaching the ground. However, when the terrestrial cues around the tree were blocked, foragers were unable to orient correctly, suggesting that the surrounding panorama is critical to successful orientation on the tree. Through analysis of panoramic pictures, we show that views acquired at the base of the foraging tree nest can provide reliable nest-ward orientation up to 1.75 m above the ground. We discuss, how animals descending from trees compare their current scene to a memorised scene and report on the similarities in visually guided behaviour while navigating on the ground and descending from trees.

  12. Serological and molecular inquiry of Chagas disease in an Afro-descendant settlement in Mato Grosso do Sul State, Brazil.

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    Mariana Furquim da Silva Martins

    Full Text Available Furnas do Dionísio is a Brazilian Afro-descendant settlement in the city of Jaraguari, 21.4 miles from Campo Grande, Mato Grosso do Sul, Brazil. Approximately 96 families live in this quilombola (Maroon settlement, also known in Brazil as a remnant community of descendants of African slaves. Recent studies found 20% of households were infested by triatomines, 18% of insects captured in the community were infected by Trypanosoma cruzi, and 22.7% of dogs presented T. cruzi antibodies. The low prevalence of Chagas disease observed in humans in Mato Grosso do Sul State is attributed to its arrival via colonist migration and subsequent transplacental transmission. In order to gain a better understanding of the T. cruzi cycle in residents of the study community, serological and molecular tests were carried out to diagnose Chagas disease. In the present study, 175 residents between 2 and 80 years old were included. A total of 175 participants were interviewed and 170 provided blood samples, which were tested for T. cruzi antibodies with serological tests. Molecular diagnosis was performed in 167 participants by PCR (KDNA and NPCR (satellite DNA tests. One of the 170 samples tested positive for all serological tests performed. The overall frequency of Chagas disease in the community was low (0.6%. Interview responses revealed that 66.3% knew of triatomine insects and 65.7% reported having had no contact with them. Physical improvements to residences, together with vector surveillance and control by the State and municipal governments and local ecological conservation contribute to the low frequency of the Chagas disease in this quilombola community.

  13. Serological and molecular inquiry of Chagas disease in an Afro-descendant settlement in Mato Grosso do Sul State, Brazil.

    Science.gov (United States)

    Martins, Mariana Furquim da Silva; Pereira, Mariane Barroso; Ferreira, Juliana de Jesus Guimarães; França, Adriana de Oliveira; Cominetti, Marlon Cézar; Ferreira, Eduardo de Castro; Dorval, Maria Elizabeth Moraes Cavalheiros; Rossi, Cláudio Lúcio; Mazon, Sílvia de Barros; de Almeida, Eros Antonio; Costa, Sandra Cecília Botelho; Marcon, Gláucia Elisete Barbosa

    2018-01-01

    Furnas do Dionísio is a Brazilian Afro-descendant settlement in the city of Jaraguari, 21.4 miles from Campo Grande, Mato Grosso do Sul, Brazil. Approximately 96 families live in this quilombola (Maroon) settlement, also known in Brazil as a remnant community of descendants of African slaves. Recent studies found 20% of households were infested by triatomines, 18% of insects captured in the community were infected by Trypanosoma cruzi, and 22.7% of dogs presented T. cruzi antibodies. The low prevalence of Chagas disease observed in humans in Mato Grosso do Sul State is attributed to its arrival via colonist migration and subsequent transplacental transmission. In order to gain a better understanding of the T. cruzi cycle in residents of the study community, serological and molecular tests were carried out to diagnose Chagas disease. In the present study, 175 residents between 2 and 80 years old were included. A total of 175 participants were interviewed and 170 provided blood samples, which were tested for T. cruzi antibodies with serological tests. Molecular diagnosis was performed in 167 participants by PCR (KDNA) and NPCR (satellite DNA) tests. One of the 170 samples tested positive for all serological tests performed. The overall frequency of Chagas disease in the community was low (0.6%). Interview responses revealed that 66.3% knew of triatomine insects and 65.7% reported having had no contact with them. Physical improvements to residences, together with vector surveillance and control by the State and municipal governments and local ecological conservation contribute to the low frequency of the Chagas disease in this quilombola community.

  14. Neoadjuvant and Concurrent Chemotherapy Have Varied Impacts on the Prognosis of Patients with the Ascending and Descending Types of Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiotherapy.

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    Ji-Jin Yao

    Full Text Available To compare the outcomes of patients with ascending type (T4&N0-1 and descending type (T1-2&N3 of nasopharyngeal carcinoma (NPC treated with concurrent chemoradiotherapy (CCRT, neoadjuvant chemotherapy (NACT + intensity-modulated radiotherapy (RT or NACT + CCRT.Retrospective analysis of 839 patients with ascending or descending types of NPC treated at a single institution between October 2009 to February 2012. CCRT was delivered to 236 patients, NACT + RT to 302 patients, and NACT + CCRT to 301 patients.The 4-year overall survival rate, distant metastasis-free survival rate, local relapse-free survival rate, nodal relapse-free survival rate, loco-regional relapse-free survival rate, and progression free survival rate were 75.2% and 73.4% (P = 0.114, 85.7% and 74.1% (P = 0.008, 88.8% and 97.1% (P = 0.013, 96.9% and 94.1% (P = 0.122, 86.9% and 91.2% (P = 0.384, 73.7% and 66.2% (P = 0.063 in ascending type and descending type. Subgroup analyses indicated that NACT + RT significantly improved distant metastasis-free survival rate and progression-free survival rate when compared with CCRT in the ascending type, and there were no significant differences between the survival curves of NACT +RT and NACT + CCRT. For descending type, there were no significant differences among the survival curves of NACT +RT, CCRT, and NACT + CCRT groups, and the survival benefit mainly came from CCRT.Compared with NACT + CCRT or CCRT, NACT + RT may be a reasonable approach for ascending type. Although concurrent chemotherapy was effective in descending type, NACT + CCRT may be a more appropriate strategy for descending type.

  15. Optogenetic modulation of descending prefrontocortical inputs to the dorsal raphe bidirectionally bias socioaffective choices after social defeat

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    Collin eChallis

    2014-02-01

    Full Text Available It has been well established that modulating serotonin (5-HT levels in humans and animals affects perception and response to social threats, however the circuit mechanisms that control 5-HT output during social interaction are not well understood. A better understanding of these systems could provide groundwork for more precise and efficient therapeutic interventions. Here we examined the organization and plasticity of microcircuits implicated in top-down control of 5-HT neurons in the dorsal raphe nucleus (DRN by excitatory inputs from the ventromedial prefrontal cortex (vmPFC and their role in social approach-avoidance decisions. We did this in the context of a social defeat model that induces a long lasting form of social aversion that is reversible by antidepressants. We first used viral tracing and Cre-dependent genetic identification of vmPFC glutamatergic synapses in the DRN to determine their topographic distribution in relation to 5-HT and GABAergic subregions and found that excitatory vmPFC projections primarily localized to GABA-rich areas of the DRN. We then used optogenetics in combination with cFos mapping and slice electrophysiology to establish the functional effects of repeatedly driving vmPFC inputs in DRN. We provide the first direct evidence that vmPFC axons drive synaptic activity and immediate early gene expression in genetically identified DRN GABA neurons through an AMPA receptor-dependent mechanism. In contrast, we did not detect vmPFC-driven synaptic activity in 5-HT neurons and cFos induction in 5-HT neurons was limited. Finally we show that optogenetically increasing or decreasing excitatory vmPFC input to the DRN during sensory exposure to an aggressor’s cues enhances or diminishes avoidance bias, respectively. These results clarify the functional organization of vmPFC-DRN pathways and identify GABAergic neurons as a key cellular element filtering top-down vmPFC influences on affect-regulating 5-HT output.

  16. Neuronal factors determining high intelligence.

    Science.gov (United States)

    Dicke, Ursula; Roth, Gerhard

    2016-01-05

    Many attempts have been made to correlate degrees of both animal and human intelligence with brain properties. With respect to mammals, a much-discussed trait concerns absolute and relative brain size, either uncorrected or corrected for body size. However, the correlation of both with degrees of intelligence yields large inconsistencies, because although they are regarded as the most intelligent mammals, monkeys and apes, including humans, have neither the absolutely nor the relatively largest brains. The best fit between brain traits and degrees of intelligence among mammals is reached by a combination of the number of cortical neurons, neuron packing density, interneuronal distance and axonal conduction velocity--factors that determine general information processing capacity (IPC), as reflected by general intelligence. The highest IPC is found in humans, followed by the great apes, Old World and New World monkeys. The IPC of cetaceans and elephants is much lower because of a thin cortex, low neuron packing density and low axonal conduction velocity. By contrast, corvid and psittacid birds have very small and densely packed pallial neurons and relatively many neurons, which, despite very small brain volumes, might explain their high intelligence. The evolution of a syntactical and grammatical language in humans most probably has served as an additional intelligence amplifier, which may have happened in songbirds and psittacids in a convergent manner. © 2015 The Author(s).

  17. More questions for mirror neurons.

    Science.gov (United States)

    Borg, Emma

    2013-09-01

    The mirror neuron system is widely held to provide direct access to the motor goals of others. This paper critically investigates this idea, focusing on the so-called 'intentional worry'. I explore two answers to the intentional worry: first that the worry is premised on too limited an understanding of mirror neuron behaviour (Sections 2 and 3), second that the appeal made to mirror neurons can be refined in such a way as to avoid the worry (Section 4). I argue that the first response requires an account of the mechanism by which small-scale gestures are supposedly mapped to larger chains of actions but that none of the extant accounts of this mechanism are plausible. Section 4 then briefly examines refinements of the mirror neuron-mindreading hypothesis which avoid the intentional worry. I conclude that these refinements may well be plausible but that they undermine many of the claims standardly made for mirror neurons. Copyright © 2012 Elsevier Inc. All rights reserved.

  18. Towards a Neuronal Gauge Theory

    Science.gov (United States)

    Sengupta, Biswa; Tozzi, Arturo; Cooray, Gerald K.; Douglas, Pamela K.; Friston, Karl J.

    2016-01-01

    Given the amount of knowledge and data accruing in the neurosciences, is it time to formulate a general principle for neuronal dynamics that holds at evolutionary, developmental, and perceptual timescales? In this paper, we propose that the brain (and other self-organised biological systems) can be characterised via the mathematical apparatus of a gauge theory. The picture that emerges from this approach suggests that any biological system (from a neuron to an organism) can be cast as resolving uncertainty about its external milieu, either by changing its internal states or its relationship to the environment. Using formal arguments, we show that a gauge theory for neuronal dynamics—based on approximate Bayesian inference—has the potential to shed new light on phenomena that have thus far eluded a formal description, such as attention and the link between action and perception. PMID:26953636

  19. Neuronal oscillations in Parkinson's disease.

    Science.gov (United States)

    Witcher, Mark; Moran, Rosalyn; Tatter, Stephen B; Laxton, Adrian W

    2014-06-01

    Parkinson's Disease (PD), characterized by tremor, rigidity, and bradykinesia, is one of the most prevalent neurodegenerative disorders in the world. The pathological hallmark of PD is the loss of dopaminergic cells in the substantia nigra and other brain regions. The pathophysiological mechanisms by which dopaminergic cell loss leads to the motor manifestations of PD are yet to be fully elucidated. A growing body of evidence has revealed abnormal neuronal oscillations within and between multiple brain regions in PD. Unique oscillatory patterns are associated with specific motor abnormalities in PD. Therapies, such as dopaminergic medication and deep brain stimulation that disrupt these abnormal neuronal oscillatory patterns produce symptomatic improvement in PD patients. These findings emphasize the importance of abnormal neuronal oscillations in the pathophysiology of PD, making the disruption of these oscillatory patterns a promising target in the development of effective PD treatments.

  20. Prospective Coding by Spiking Neurons.

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    Johanni Brea

    2016-06-01

    Full Text Available Animals learn to make predictions, such as associating the sound of a bell with upcoming feeding or predicting a movement that a motor command is eliciting. How predictions are realized on the neuronal level and what plasticity rule underlies their learning is not well understood. Here we propose a biologically plausible synaptic plasticity rule to learn predictions on a single neuron level on a timescale of seconds. The learning rule allows a spiking two-compartment neuron to match its current firing rate to its own expected future discounted firing rate. For instance, if an originally neutral event is repeatedly followed by an event that elevates the firing rate of a neuron, the originally neutral event will eventually also elevate the neuron's firing rate. The plasticity rule is a form of spike timing dependent plasticity in which a presynaptic spike followed by a postsynaptic spike leads to potentiation. Even if the plasticity window has a width of 20 milliseconds, associations on the time scale of seconds can be learned. We illustrate prospective coding with three examples: learning to predict a time varying input, learning to predict the next stimulus in a delayed paired-associate task and learning with a recurrent network to reproduce a temporally compressed version of a sequence. We discuss the potential role of the learning mechanism in classical trace conditioning. In the special case that the signal to be predicted encodes reward, the neuron learns to predict the discounted future reward and learning is closely related to the temporal difference learning algorithm TD(λ.

  1. Norovirus diversity in diarrheic children from an African-descendant settlement in Belém, Northern Brazil.

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    Glicélia Cruz Aragão

    Full Text Available Norovirus (NoV, sapovirus (SaV and human astrovirus (HAstV are viral pathogens that are associated with outbreaks and sporadic cases of gastroenteritis. However, little is known about the occurrence of these pathogens in relatively isolated communities, such as the remnants of African-descendant villages ("Quilombola". The objective of this study was the frequency determination of these viruses in children under 10 years, with and without gastroenteritis, from a "Quilombola" Community, Northern Brazil. A total of 159 stool samples were obtained from April/2008 to July/2010 and tested by an enzyme immunoassay (EIA and reverse transcription-polymerase chain reaction (RT-PCR to detect NoV, SaV and HAstV, and further molecular characterization was performed. These viruses were detected only in the diarrheic group. NoV was the most frequent viral agent detected (19.7%-16/81, followed by SaV (2.5%-2/81 and HAstV (1.2%-1/81. Of the 16 NoV-positive samples, 14 were sequenced with primers targeting the B region of the polymerase (ORF1 and the D region of the capsid (ORF2. The results showed a broad genetic diversity of NoV, with 12 strains being classified as GII-4 (5-41.7%, GII-6 (3-25%, GII-7 (2-16.7%, GII-17 (1-8.3% and GI-2 (1-8.3%, as based on the polymerase region; 12 samples were classified, based on the capsid region, as GII-4 (6-50%, being 3-2006b variant and 3-2010 variant, GII-6 (3-25%, GII-17 (2-16.7% and GII-20 (1-8.3%. One NoV-strain showed dual genotype specificity, based on the polymerase and capsid region (GII-7/GII-20. This study provides, for the first time, epidemiological and molecular information on the circulation of NoV, SaV and HAstV in African-descendant communities in Northern Brazil and identifies NoV genotypes that were different from those detected previously in studies conducted in the urban area of Belém. It remains to be determined why a broader NoV diversity was observed in such a semi-isolated community.

  2. Calcium signals in olfactory neurons.

    Science.gov (United States)

    Tareilus, E; Noé, J; Breer, H

    1995-11-09

    Laser scanning confocal microscopy in combination with the fluorescent calcium indicators Fluo-3 and Fura-Red was employed to estimate the intracellular concentration of free calcium ions in individual olfactory receptor neurons and to monitor temporal and spatial changes in the Ca(2+)-level upon stimulation. The chemosensory cells responded to odorants with a significant increase in the calcium concentration, preferentially in the dendritic knob. Applying various stimulation paradigma, it was found that in a population of isolated cells, subsets of receptor neurons display distinct patterns of responsiveness.

  3. Toward an ethnography of silence: the lived presence of the past in the everyday life of Holocaust trauma survivors and their descendants in Israel.

    Science.gov (United States)

    Kidron, Carol A

    2009-02-01

    Despite the abundant scholarship on posttraumatic stress disorder (PTSD) and the memoropolitics entailed by testimonial accounts of trauma and genocide, little is known of the everyday experience of trauma survivors and their descendants. Survivor silence is thought to signify only psychological or political repression and the "unspeakability" of traumatic pasts. It is widely accepted that the everyday lives of trauma victims and their descendants entail only the "absence of presence" of the past and the absence of descendant knowledge of that past, while the familial social milieu is thought to foster only the wounds of transmitted PTSD. Contrary to the literature, ethnographic accounts of Holocaust descendants depict the survivor home as embedding the nonpathological presence of the Holocaust past within silent, embodied practices, person-object interaction, and person-person interaction. These silent traces form an experiential matrix of Holocaust presence that sustains familial "lived memory" of the past and transmits tacit knowledge of the past within the everyday private social milieu. The ethnography of silent memory may also provide a tentative model of nontraumatic individual and familial memory work in everyday life.

  4. Endovascular Stent Graft Placement in the Treatment of Ruptured Tuberculous Pseudoaneurysm of the Descending Thoracic Aorta: Case Report and Review of the Literature

    International Nuclear Information System (INIS)

    Dogan, Sozen; Memis, Ahmet; Kale, Arzum; Buket, Suat

    2009-01-01

    We report a successful repair of a ruptured tuberculous pseudoaneurysm of the descending thoracic aorta by endovascular stent graft placement. This procedure is starting to be accepted as an alternative method to surgery, and we review similar cases in the literature.

  5. The Rise of the Second Generation : the role of social capital in the upward mobility of descendants of immigrants from Turkey and Morocco

    NARCIS (Netherlands)

    S. Rezai (Sara)

    2017-01-01

    textabstractThe interviews with descendants of immigrants concern the role that social actors played during their educational and professional pathways. Interview material from the research projects Pathways to Success Project and the international ELITES project (ERC grant 284223) were used for

  6. Morbidity, Self-Perceived Health and Mortality Among non-Western Immigrants and Their Descendants in Denmark in a Life Phase Perspective

    DEFF Research Database (Denmark)

    Jervelund, Signe Smith; Malik, Sanam; Ahlmark, Nanna

    2017-01-01

    To enable preventive policies to address health inequity across ethnic groups, this review overviews the current knowledge on morbidity, self-perceived health and mortality among non-Western immigrants and their descendants in Denmark. A systematic search in PUBMED, SCOPUS, Embase and Cochrane...

  7. Pens and Ploughshares: The Historical Use of Art by African-Descended Women to Create Social Justice in the US Neo-Slavery Era

    Science.gov (United States)

    View, Jenice L.

    2013-01-01

    In the period after the 1896 U.S. Supreme Court decision (Plessy v. Ferguson), "white" supremacy was codified and reinforced through law, custom, and mob violence. Despite this, African-descended women artists in the Western Hemisphere committed the revolutionary act of declaring, "I am; I am here; I am here remaking/reimagining the…

  8. Recovery of neuronal and network excitability after spinal cord injury and implications for spasticity

    Directory of Open Access Journals (Sweden)

    Jessica Maria D'Amico

    2014-05-01

    Full Text Available The state of areflexia and muscle weakness that immediately follows a spinal cord injury is gradually replaced by the recovery of neuronal and network excitability, leading to both improvements in residual motor function and the development of spasticity. In this review we summarize recent animal and human studies that describe how motoneurons and their activation by sensory pathways become hyperexcitable to compensate for the reduction of descending and movement-induced sensory inputs and the eventual impact on the muscle. We discuss how replacing lost patterned activation of the spinal cord by activating synaptic inputs via assisted movements, pharmacology or electrical stimulation may help to recover lost spinal inhibition. This may lead to a reduction of uncontrolled activation of the spinal cord and thus, improve its controlled activation by synaptic inputs to ultimately normalize circuit function. Increasing the excitation of the spinal cord below an injury with spared descending and/or peripheral functional synaptic activation, instead of suppressing it pharmacologically, may provide the best avenue to improve residual motor function and manage spasticity after spinal cord injury.

  9. Detection of genomic instability in descendants of male mice exposed to chronic low-level gamma-radiation using the test 'adaptive response'

    International Nuclear Information System (INIS)

    Rozanova, O.M.; Zaichkina, S.I.; Akhmadieva, A.; Aptikaeva, G.F.; Klokov, D.J.

    2003-01-01

    Full text: The goal of the present study was to examine whether the genomic instability can be revealed in vivo using the test 'adaptive response' (AR). Two-month-old BALB/C male mice were subjected to chronic irradiation in the gamma-field with a dose of 0.1 Gy (0.01 Gy/day) and a dose of 0.5 Gy (0.01 and 0.05 Gy/day). Control animals were kept under similar conditions but without irradiation. Fifteen days after the irradiation, males from the irradiated and control groups were mated in separate cages with unirradiated females for 2 weeks. The males, descendants from irradiated and unirradiated parents, at an age of two months were subjected to additional irradiation with a dose of 1.5 Gy. To reveal the genetic instability using the AR test, another group of males, the descendants from irradiated and unirradiated parents, were exposed to acute irradiation by the scheme of AR: with an adapting dose (D1) of 0.1 Gy (0.125 Gy/min) followed after a day by a challenging dose (D2) of 1.5 Gy (0.47 Gy/min). After 28 h, the animals of all groups were killed. Bone marrow specimens for calculating micronuclei (MN) in polychromatophyl erythrocytes (PCE) were prepared. It was found that in descendants that resulted from unirradiated parents and the parents irradiated with a dose of 0.1 Gy, the percentages of PCE with injuries were nearly equal. Upon irradiation of parents with a dose of 0.5 Gy, the percentage of PCE with MN in descendants increased. The examination of radiosensitivity of descendants from irradiated parents showed that the percentage of PCE with MN decreased three-to-fourfold (depending on the dose of irradiation of the parents) compared to descendants from unirradiated parents. If the descendants from exposed parents were irradiated by the scheme of AR, no AR was observed. Thus, the experimental data indicated that, it is possible to detect the transition of gamma-radiation-induced genomic instability in sex cells of male parents into somatic cells of mice (F1

  10. [What mirror neurons have revealed: revisited].

    Science.gov (United States)

    Murata, Akira; Maeda, Kazutaka

    2014-06-01

    The first paper on mirror neurons was published in 1992. In the span of over two decades since then, much knowledge about the relationship between social cognitive function and the motor control system has been accumulated. Direct matching of visual actions and their corresponding motor representations is the most important functional property of mirror neuron. Many studies have emphasized intrinsic simulation as a core concept for mirror neurons. Mirror neurons are thought to play a role in social cognitive function. However, the function of mirror neurons in the macaque remains unclear, because such cognitive functions are limited or lacking in macaque monkeys. It is therefore important to discuss these neurons in the context of motor function. Rizzolatti and colleagues have stressed that the most important function of mirror neurons in macaques is recognition of actions performed by other individuals. I suggest that mirror neurons in the Macaque inferior pariental lobule might be correlated with body schema. In the parieto-premotor network, matching of corollary discharge and actual sensory feedback is an essential neuronal operation. Recently, neurons showing mirror properties were found in some cortical areas outside the mirror neuron system. The current work would revisit the outcomes of mirror neuron studies to discuss the function of mirror neurons in the monkey.

  11. Oxytocin-induced antinociception in the spinal cord is mediated by a subpopulation of glutamatergic neurons in lamina I-II which amplify GABAergic inhibition

    Directory of Open Access Journals (Sweden)

    Schlichter Rémy

    2008-05-01

    Full Text Available Abstract Background Recent evidence suggests that oxytocin (OT, secreted in the superficial spinal cord dorsal horn by descending axons of paraventricular hypothalamic nucleus (PVN neurons, produces antinociception and analgesia. The spinal mechanism of OT is, however, still unclear and requires further investigation. We have used patch clamp recording of lamina II neurons in spinal cord slices and immunocytochemistry in order to identify PVN-activated neurons in the superficial layers of the spinal cord and attempted to determine how this neuronal population may lead to OT-mediated antinociception. Results We show that OT released during PVN stimulation specifically activates a subpopulation of lamina II glutamatergic interneurons which are localized in the most superficial layers of the dorsal horn of the spinal cord (lamina I-II. This OT-specific stimulation of glutamatergic neurons allows the recruitment of all GABAergic interneurons in lamina II which produces a generalized elevation of local inhibition, a phenomenon which might explain the reduction of incoming Aδ and C primary afferent-mediated sensory messages. Conclusion Our results obtained in lamina II of the spinal cord provide the first clear evidence of a specific local neuronal network that is activated by OT release to induce antinociception. This OT-specific pathway might represent a novel and interesting therapeutic target for the management of neuropathic and inflammatory pain.

  12. [Hybrid treatment of patients with aneurysms and dissections of the aortic arch and descending portion of the thoracic aorta].

    Science.gov (United States)

    Shlomin, V V; Gordeev, M L; Zverev, D A; Shloĭdo, E A; Uspenskiĭ, V E; Zvereva, E D; Bondarenko, P B; Puzdriak, P D

    The authors share herein their experience with hybrid surgical treatment of 21 patients presenting with lesions of the aortic arch and descending thoracic aorta. Aortic pathology included dissection of the thoracoabdominal aorta (n=15), a sacciform aneurysm of the aortic arch (n=5), and a spindle-shaped aneurysm of the distal portions of the aortic arch (n=1). The first stage consisted of the following operations: transposition of the left subclavian artery into the left common carotid artery (n=9; 42.8%), partial debranching (n=11; 52.5%), and total debranching (n=1; 4.7%). The second stage consisted in implantation of a stent graft: to the thoracic aorta in 18 (85.8%) cases, and to the thoracic and abdominal portions of the aorta in 3 (14.2%) cases. The most significant complications of the immediate postoperative period included acute cerebral circulation impairment (n=1) and local dissection of the ascending aorta (n=1). Type I endoleaks were observed in 4 (19%) patients, type II endoleaks in 1 (4.7%), and type III endoleaks in 1 (4.7%). The mean duration of the follow up after discharge from hospital amounted to 11.6±7.9 months. In 4 patients after 6 months the findings of the control MSCT angiography showed no significant changes of the endoleaks. 1-year patency of the shunted branches of the aortic arch amounted to 95.2%. The cumulative survival rate amounted to 95.2%.

  13. Anastomotic stenosis of the descending colon caused by barium granuloma formation following barium peritonitis: report of a case.

    Science.gov (United States)

    Kitajima, Toshihiro; Tomizawa, Kenji; Hanaoka, Yutaka; Toda, Shigeo; Matoba, Shuichiro; Kuroyanagi, Hiroya; Oota, Yasunori

    2014-11-01

    Anastomotic stricture reportedly often recurs following barium peritonitis, regardless of whether the anastomotic diameter is initially sufficient. However, the causes of repetitive stricture have not been clarified. We report a case that suggests the pathophysiology of recurrent anastomotic strictures following barium peritonitis. The patient was a 39-year-old Japanese man with idiopathic perforation of the descending colon after undergoing an upper gastrointestinal barium contrast study. After emergency peritoneal lavage and diverting colostomy, created using the perforated region, the patient recovered uneventfully and 3 months later, the colostomy was closed and the perforated colon was resected. However, 7 months after colostomy closure, abdominal distention gradually developed, and colonoscopy revealed an anastomotic stricture. The patient was referred to our hospital where he underwent resection of the anastomotic stricture. The surgical specimen exhibited barium granulomas not only in the subserosa of the entire specimen, but also in the submucosa and lamina propria localized in the anastomotic site. These findings suggest that barium was embedded in the submucosa and lamina propria with manipulation of the stapled anastomosis and that the barium trapped in the anastomotic site caused persistent inflammation, resulting in an anastomotic stricture.

  14. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Directory of Open Access Journals (Sweden)

    Fenglin Song

    2014-01-01

    Full Text Available To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV were less than those in the control group (using Gore-Tex. The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  15. An Experimental Study to Replace the Thoracic Descending Aorta for Pigs with a Self-Made Sutureless Blood Vessel

    Science.gov (United States)

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV) were less than those in the control group (using Gore-Tex). The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility. PMID:24696856

  16. Derivation of flow related risk indices for stenosed left anterior descending coronary arteries with the use of computer simulations.

    Science.gov (United States)

    Papadopoulos, Konstantinos P; Gavaises, Manolis; Pantos, Ioannis; Katritsis, Demosthenes G; Mitroglou, Nicholas

    2016-09-01

    The geometry of the coronary vessel network is believed to play a decisive role in the initiation, progression and outcome of coronary artery disease (CAD) and the occurrence of acute coronary syndromes (ACS). It also determines the flow field in the coronary artery which can be linked to CAD evolution. In this work geometric 3D models of left anterior descending (LAD) coronary arteries associated with either myocardial infarction (MI) or stable (STA) CAD were constructed. Transient numerical simulations of the flow for each model showed that specific flow patterns develop in different extent in the different groups examined. Recirculation zones, present distal the stenosis in all models, had larger extent and duration in MI cases. For mild stenosis (up to 50%) areas with low time averaged wall shear stress TAWSS (3Pa) appeared only in MI models; in moderate and severe stenosis (>50%) these areas were present in all models but were significantly larger for MI than STA models. These differentiations were expressed via numerical indices based on TAWSS, oscillating shear index (OSI) and relative residence time (RRT). Additionally we introduced the coagulation activation index (CAI), based on the threshold behaviour of coagulation initiation, which exceeded the suggested threshold only for MI models with intermediate stenosis (up to 50%). These results show that numerical simulations of flow can produce arithmetic indices linked with the risk of CAD complications. Copyright © 2016 IPEM. Published by Elsevier Ltd. All rights reserved.

  17. Transthoracic ultrasonic tissue indices identify patients with severe left anterior descending artery stenosis. Correlation with fractional flow reserve. Pilot study.

    Science.gov (United States)

    Dobrowolski, Piotr; Kowalski, Mirosław; Rybicka, Justyna; Lech, Agnieszka; Tyczyński, Paweł; Witkowski, Adam; Hoffman, Piotr

    2016-01-01

    The aim of this study was to evaluate the potential clinical application of ultrasonic tissue indices, with a focus on systolic strain (SS) and systolic strain rate (SSR) parameters derived from transthoracic echocardiography, in the assessment of left anterior descending artery (LAD) stenosis. The data of 30 patients with significant LAD stenosis were analysed. All patients underwent transthoracic echocardiography to obtain systolic myocardial velocity (Sm), longitudinal SS, and SSR from basal, mid, and apical segments of anterior and inferior walls in two-chamber apical view. Severity of LAD obstruction was measured by means of fractional flow reserve (FFR) during coronary catheterisation. Systolic velocities, strain, and strain rate measured in basal, middle, and apical segments of the anterior left ventricular (LV) wall were lower when compared to those obtained from the corresponding, i.e. unaffected, inferior LV wall. There was a significant correlation between FFR and the value of SS, SSR characterising the apical LV segment of the anterior wall (r = -0.583, p = 0.01; r = -0.598, p = 0.01, respectively). Moreover, we found significant correlation between FFR and Sm in the mid-segment of the LV anterior wall (r = 0.611, p = 0.009). We conclude that SS and SSR obtained from the apical segment of the anterior LV wall may be related to the severity of LAD stenosis.

  18. An experimental study to replace the thoracic descending aorta for pigs with a self-made sutureless blood vessel.

    Science.gov (United States)

    Song, Fenglin; Zhou, Wenwu; Tang, Tao; Li, Xiaobing; Wu, Xiaoming; Yang, Jinfu

    2014-01-01

    To simplify the procedure of blood vessel replacement operation and shorten the vascular anastomosis time, we developed a special artificial blood vessel which can be connected to native blood vessels without suture. The self-made sutureless blood vessel (SMSBV) was made from two titanium connectors and a Gore-Tex graft. To investigate blood compatibility and histocompatibility of the SMSBV, we carried thoracic descending aorta replacement using either SMSBV or Gore-Tex, respectively, in pigs. The aortic clamp time and the operative blood loss in the experimental group (using SMSBV) were less than those in the control group (using Gore-Tex). The whole blood hematocrit, platelet count, plasma soluble P-selectin, plasma free hemoglobin, and interleukins 2, 6 at each time point were not different significantly between the two groups. Light microscopy and transmission electron microscopy examination showed there were layers of vascular smooth muscle cells and endothelial cells adhered in the inner wall of artificial blood vessel without any signs of thrombosis. Based on the result, we have drawn the conclusion that the application of SMSBV can significantly shorten the vascular anastomosis time, reduce operative blood loss, and show good blood and tissue compatibility.

  19. [Food insecurity in rural communities in Northeast Brazil: does belonging to a slave-descendent community make a difference?

    Science.gov (United States)

    Silva, Etna Kaliane Pereira da; Medeiros, Danielle Souto de; Martins, Poliana Cardoso; Sousa, Líllian de Almeida; Lima, Gislane Pereira; Rêgo, Maria Amanda Sousa; Silva, Tainan Oliveira da; Freire, Alessandra Silva; Silva, Fernanda Moitinho

    2017-06-01

    This study aimed to measure the prevalence of food insecurity in a rural area of Northeast Brazil and investigate this outcome according to residence in quilombola communities (descendants of African slaves) versus non-quilombola communities. This was a cross-sectional study in 21 rural communities, 9 of which quilombolas, in 2014, using the Brazilian Food Insecurity Scale (EBIA). Prevalence rates and prevalence ratios were estimated for food insecurity, and Poisson multiple regression analysis with robust variance was performed. Food insecurity was found in 52.1% of the families: 64.9% in quilombola communities and 42% in the others. Food insecurity was associated with belonging to a quilombola community (PR = 1.25), lower economic status (PR = 1.89; 2.98, and 3.22 for status C2, D, and E, respectively), beneficiaries of Bolsa Família program (PR = 1.52), and four or more household members (PR = 1.20). Food insecurity prevalence was high in the entire population, but it was even higher in quilombola communities, even though they belonged to the same coverage area. The results emphasize this population's vulnerability.

  20. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Reiber, J.H.C.; Serruys, P.W.; Slager, C.J.; Erasmus Univ., Rotterdam

    1986-01-01

    In order to evaluate during cardiac catheterization what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer based quantitative analysis of coronary angiograms was performed in 31 patients with isolated proximal left anterior descending coronary artery disease. The angiographic severity of the stenosis was compared with the transstenotic pressure gradient measured with the dilatation catheter during angioplasty and the results of exercise thallium scintigraphy. A curvilinear relation was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal obstruction area (after subtracting the area of the angioplasty catheter). This relation was best fitted by the equation: normalized mean pressure gradient = a + b · log [obstruction area], r = 0.74. The measurements of the percent area stenosis (cut-off 80%) and of the transstenotic pressure gradient (cut-off 0.30) obtained at rest, correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients. (Auth.)

  1. Quantitative angiography of the left anterior descending coronary artery: correlations with pressure gradient and results of exercise thallium scintigraphy

    International Nuclear Information System (INIS)

    Wijns, W.; Serruys, P.W.; Reiber, J.H.; van den Brand, M.; Simoons, M.L.; Kooijman, C.J.; Balakumaran, K.; Hugenholtz, P.G.

    1985-01-01

    To evaluate, during cardiac catheterization, what constitutes a physiologically significant obstruction to blood flow in the human coronary system, computer-based quantitative analysis of coronary angiograms was performed on the angiograms of 31 patients with isolated disease of the proximal left anterior descending coronary artery. The angiographic severity of stenosis was compared with the transstenotic pressure gradient measured with the dilation catheter during angioplasty and with the results of exercise thallium scintigraphy. A curvilinear relationship was found between the pressure gradient across the stenosis (normalized for the mean aortic pressure) and the residual minimal area of obstruction (after subtracting the area of the angioplasty catheter). This relationship was best fitted by the equation: normalized mean pressure gradient . a + b . log [obstruction area], r . .74. The measurements of the percent area of stenosis (cutoff 80%) and of the transstenotic pressure gradient (cutoff 0.30) obtained at rest correctly predicted the occurrence of thallium perfusion defects induced by exercise in 83% of the patients

  2. Celiac Trunk Embolization, as a Means of Elongating Short Distal Descending Thoracic Aortic Aneurysm Necks, Prior to Endovascular Aortic Repair

    International Nuclear Information System (INIS)

    Belenky, Alexander; Haddad, Menashe; Idov, Igor; Knizhnik, Michael; Litvin, Sergey; Bachar, Gil N.; Atar, Eli

    2009-01-01

    The purpose of this study was to report our experience in elongating short distal necks of descending thoracic aortic aneurysms (DTAAs) by coil embolization of the celiac trunk prior to endovascular aneurysm repair (EVAR). During 6 years seven patients (five men and two women; mean age, 74) who had DTAAs with short distal necks unsuitable for conventional EVAR, and well patent superior and inferior mesenteric arteries based on CT, were treated in one session with EVAR after the celiac trunk was coil embolized to elongate the neck. All patients were followed by CT every 3 months in the first year and every 6 months thereafter. Technical success was achieved in all patients, and no early or late ischemic complications were noted. No procedural complications occurred and good aneurysm sealing was obtained in all patients. Three endoleaks were identified after 3 months (one patient) and 6 months (two patients); all were treated successfully with insertion of an additional stent-graft. In patients with DTAAs who are candidates for EVAR but have short aneurysm distal necks, celiac trunk embolization-only if the superior and inferior mesenteric arteries are patent-is a good and safe way to elongate the neck and enable EVAR.

  3. What do mirror neurons mirror?

    NARCIS (Netherlands)

    Uithol, S.; Rooij, I.J.E.I. van; Bekkering, H.; Haselager, W.F.G.

    2011-01-01

    Single cell recordings in monkeys provide strong evidence for an important role of the motor system in action understanding. This evidence is backed up by data from studies of the (human) mirror neuron system using neuroimaging or TMS techniques, and behavioral experiments. Although the data

  4. Biomechanics of single cortical neurons.

    Science.gov (United States)

    Bernick, Kristin B; Prevost, Thibault P; Suresh, Subra; Socrate, Simona

    2011-03-01

    This study presents experimental results and computational analysis of the large strain dynamic behavior of single neurons in vitro with the objective of formulating a novel quantitative framework for the biomechanics of cortical neurons. Relying on the atomic force microscopy (AFM) technique, novel testing protocols are developed to enable the characterization of neural soma deformability over a range of indentation rates spanning three orders of magnitude, 10, 1, and 0.1 μm s(-1). Modified spherical AFM probes were utilized to compress the cell bodies of neonatal rat cortical neurons in load, unload, reload and relaxation conditions. The cell response showed marked hysteretic features, strong non-linearities, and substantial time/rate dependencies. The rheological data were complemented with geometrical measurements of cell body morphology, i.e. cross-diameter and height estimates. A constitutive model, validated by the present experiments, is proposed to quantify the mechanical behavior of cortical neurons. The model aimed to correlate empirical findings with measurable degrees of (hyper)elastic resilience and viscosity at the cell level. The proposed formulation, predicated upon previous constitutive model developments undertaken at the cortical tissue level, was implemented in a three-dimensional finite element framework. The simulated cell response was calibrated to the experimental measurements under the selected test conditions, providing a novel single cell model that could form the basis for further refinements. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  5. Optimal compensation for neuron loss

    Science.gov (United States)

    Barrett, David GT; Denève, Sophie; Machens, Christian K

    2016-01-01

    The brain has an impressive ability to withstand neural damage. Diseases that kill neurons can go unnoticed for years, and incomplete brain lesions or silencing of neurons often fail to produce any behavioral effect. How does the brain compensate for such damage, and what are the limits of this compensation? We propose that neural circuits instantly compensate for neuron loss, thereby preserving their function as much as possible. We show that this compensation can explain changes in tuning curves induced by neuron silencing across a variety of systems, including the primary visual cortex. We find that compensatory mechanisms can be implemented through the dynamics of networks with a tight balance of excitation and inhibition, without requiring synaptic plasticity. The limits of this compensatory mechanism are reached when excitation and inhibition become unbalanced, thereby demarcating a recovery boundary, where signal representation fails and where diseases may become symptomatic. DOI: http://dx.doi.org/10.7554/eLife.12454.001 PMID:27935480

  6. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal...

  7. Shape, connectedness and dynamics in neuronal networks.

    Science.gov (United States)

    Comin, Cesar Henrique; da Fontoura Costa, Luciano

    2013-11-15

    The morphology of neurons is directly related to several aspects of the nervous system, including its connectedness, health, development, evolution, dynamics and, ultimately, behavior. Such interplays of the neuronal morphology can be understood within the more general shape-function paradigm. The current article reviews, in an introductory way, some key issues regarding the role of neuronal morphology in the nervous system, with emphasis on works developed in the authors' group. The following topics are addressed: (a) characterization of neuronal shape; (b) stochastic synthesis of neurons and neuronal systems; (c) characterization of the connectivity of neuronal networks by using complex networks concepts; and (d) investigations of influences of neuronal shape on network dynamics. The presented concepts and methods are useful also for several other multiple object systems, such as protein-protein interaction, tissues, aggregates and polymers. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. How Might New Neurons Buffer Against Stress?

    Science.gov (United States)

    ... Institute Announcements (104 items) How Might New Neurons Buffer Against Stress? Clues Emerging from Studies in New ... better understand how having new neurons appears to buffer against stress effects on behavior, the NIMH researchers ...

  9. [The ontogeny of the mirror neuron system].

    Science.gov (United States)

    Myowa-Yamakoshi, Masako

    2014-06-01

    Abstract Humans utilize the mirror neuron system to understand and predict others' actions. However, the ontogeny of the mirror neuron system remains unknown. Whether mirror neuron function is an innate trait or whether mirror neurons acquire their sensorimotor matching properties ontogenetically remains to be clarified. In this paper, I review the ontogenetic theory of the mirror neuron system. I then discuss the functioning of the mirror neuron system in the context of social cognitive abilities, which are unique to humans. Recently, some researchers argue that it is too early to interpret the function of mirror neurons as an understanding of the underlying psychological states of others. They imply that such functioning would require inferential cognitive processes that are known to involve areas outside the mirror neuron system. Filling in this missing link may be the key to elucidating the unique ability of humans to understand others' actions.

  10. Spatial distribution of intermingling pools of projection neurons with distinct targets: A 3D analysis of the commissural ganglia in Cancer borealis.

    Science.gov (United States)

    Follmann, Rosangela; Goldsmith, Christopher John; Stein, Wolfgang

    2017-06-01

    Projection neurons play a key role in carrying long-distance information between spatially distant areas of the nervous system and in controlling motor circuits. Little is known about how projection neurons with distinct anatomical targets are organized, and few studies have addressed their spatial organization at the level of individual cells. In the paired commissural ganglia (CoGs) of the stomatogastric nervous system of the crab Cancer borealis, projection neurons convey sensory, motor, and modulatory information to several distinct anatomical regions. While the functions of descending projection neurons (dPNs) which control downstream motor circuits in the stomatogastric ganglion are well characterized, their anatomical distribution as well as that of neurons projecting to the labrum, brain, and thoracic ganglion have received less attention. Using cell membrane staining, we investigated the spatial distribution of CoG projection neurons in relation to all CoG neurons. Retrograde tracing revealed that somata associated with different axonal projection pathways were not completely spatially segregated, but had distinct preferences within the ganglion. Identified dPNs had diameters larger than 70% of CoG somata and were restricted to the most medial and anterior 25% of the ganglion. They were contained within a cluster of motor neurons projecting through the same nerve to innervate the labrum, indicating that soma position was independent of function and target area. Rather, our findings suggest that CoG neurons projecting to a variety of locations follow a generalized rule: for all nerve pathway origins, the soma cluster centroids in closest proximity are those whose axons project down that pathway. © 2017 Wiley Periodicals, Inc.

  11. Descendants and advance directives.

    Science.gov (United States)

    Buford, Christopher

    2014-01-01

    Some of the concerns that have been raised in connection to the use of advance directives are of the epistemic variety. Such concerns highlight the possibility that adhering to an advance directive may conflict with what the author of the directive actually wants (or would want) at the time of treatment. However, at least one objection to the employment of advance directives is metaphysical in nature. The objection to be discussed here, first formulated by Rebecca Dresser and labeled by Allen Buchanan as the slavery argument and David DeGrazia the someone else problem, aims to undermine the legitimacy of certain uses of advance directives by concluding that such uses rest upon an incorrect assumption about the identity over time of those ostensibly governed by the directives. There have been numerous attempts to respond to this objection. This paper aims to assess two strategies that have been pursued to cope with the problem.

  12. Descending with Angels

    DEFF Research Database (Denmark)

    Suhr, Christian

    2014-01-01

    treatment after a severe case of jinn possession which caused him to destroy the interior of a mosque, crash several cars, and insult a number of people. He sees no point in psychotropic medication since his illness has already been treated with Quranic incantations. A psychiatrist and nurse try......, and directed by Christian Suhr Produced by Persona Film, November 2013 Distribution: Documentary Educational Resources (DER, Watertown) Screening format: DCP / Blu-ray / ProRes / Mpeg4 / DVD / DV SP. Original format: XDCAM 1080p Languages: Arabic, Danish, English Subtitles: English...

  13. Spiking Neuron Network Helmholtz Machine

    Directory of Open Access Journals (Sweden)

    Pavel eSountsov

    2015-04-01

    Full Text Available An increasing amount of behavioral and neurophysiological data suggests that the brain performs optimal (or near-optimal probabilistic inference and learning during perception and other tasks. Although many machine learning algorithms exist that perform inference and learning in an optimal way, the complete description of how one of those algorithms (or a novel algorithm can be implemented in the brain is currently incomplete. There have been many proposed solutions that address how neurons can perform optimal inference but the question of how synaptic plasticity can implement optimal learning is rarely addressed. This paper aims to unify the two fields of probabilistic inference and synaptic plasticity by using a neuronal network of realistic model spiking neurons to implement a well studied computational model called the Helmholtz Machine. The Helmholtz Machine is amenable to neural implementation as the algorithm it uses to learn its parameters, called the wake-sleep algorithm, uses a local delta learning rule. Our spiking-neuron network implements both the delta rule and a small example of a Helmholtz machine. This neuronal network can learn an internal model of continuous-valued training data sets without supervision. The network can also perform inference on the learned internal models. We show how various biophysical features of the neural implementation constrain the parameters of the wake-sleep algorithm, such as the duration of the wake and sleep phases of learning and the minimal sample duration. We examine the deviations from optimal performance and tie them to the properties of the synaptic plasticity rule.

  14. BlastNeuron for Automated Comparison, Retrieval and Clustering of 3D Neuron Morphologies.

    Science.gov (United States)

    Wan, Yinan; Long, Fuhui; Qu, Lei; Xiao, Hang; Hawrylycz, Michael; Myers, Eugene W; Peng, Hanchuan

    2015-10-01

    Characterizing the identity and types of neurons in the brain, as well as their associated function, requires a means of quantifying and comparing 3D neuron morphology. Presently, neuron comparison methods are based on statistics from neuronal morphology such as size and number of branches, which are not fully suitable for detecting local similarities and differences in the detailed structure. We developed BlastNeuron to compare neurons in terms of their global appearance, detailed arborization patterns, and topological similarity. BlastNeuron first compares and clusters 3D neuron reconstructions based on global morphology features and moment invariants, independent of their orientations, sizes, level of reconstruction and other variations. Subsequently, BlastNeuron performs local alignment between any pair of retrieved neurons via a tree-topology driven dynamic programming method. A 3D correspondence map can thus be generated at the resolution of single reconstruction nodes. We applied BlastNeuron to three datasets: (1) 10,000+ neuron reconstructions from a public morphology database, (2) 681 newly and manually reconstructed neurons, and (3) neurons reconstructions produced using several independent reconstruction methods. Our approach was able to accurately and efficiently retrieve morphologically and functionally similar neuron structures from large morphology database, identify the local common structures, and find clusters of neurons that share similarities in both morphology and molecular profiles.

  15. Molecular Programming of Mesodiencephalic Dopaminergic Neuronal Subsets

    NARCIS (Netherlands)

    Smidt, M.P.

    Dopamine neurons of the substantia nigra compacta (SNc) and ventral tegmental area (VTA) are critical components of the neuronal machinery to control emotion and movement in mammals. The slow and gradual death of these neurons as seen in Parkinson's disease has triggered a large investment in

  16. Effect of Methamidophos on cerebellar neuronal cells

    African Journals Online (AJOL)

    olayemitoyin

    Taken together, our study shows that low dose methamidophos may negatively impact. TH-mediated cerebellar neuronal cell development and function, and consequently could interfere with TH-regulated neuronal events. Keywords: Methamidophos, Thyroid hormone, Purkinje cells, Granule cell, Neuronal development.

  17. Cognition and behavior in motor neuron disease

    NARCIS (Netherlands)

    Raaphorst, J.

    2015-01-01

    Motor neuron disease (MND) is a devastating neurodegenerative disorder characterized by progressive motor neuron loss, leading to weakness of the muscles of arms and legs, bulbar and respiratory muscles. Depending on the involvement of the lower and the upper motor neuron, amyotrophic lateral

  18. The spectrum of lower motor neuron syndromes

    NARCIS (Netherlands)

    van den Berg-Vos, R. M.; van den Berg, L. H.; Visser, J.; de Visser, M.; Franssen, H.; Wokke, J. H. J.

    2003-01-01

    This review discusses the most important lower motor neuron syndromes. This relatively rare group of syndromes has not been well described clinically. Two subgroups can be distinguished: patients in whom motor neurons (lower motor neuron disease (LMND)) are primarily affected or motor axons and

  19. Oscillating from Neurosecretion to Multitasking Dopamine Neurons

    Directory of Open Access Journals (Sweden)

    David R. Grattan

    2016-04-01

    Full Text Available In this issue of Cell Reports, Stagkourakis et al. (2016 report that oscillating hypothalamic TIDA neurons, previously thought to be simple neurosecretory neurons controlling pituitary prolactin secretion, control dopamine output via autoregulatory mechanisms and thus could potentially regulate other physiologically important hypothalamic neuronal circuits.

  20. Responses of single neurons and neuronal ensembles in frog first- and second-order olfactory neurons

    Czech Academy of Sciences Publication Activity Database

    Rospars, J. P.; Šanda, Pavel; Lánský, Petr; Duchamp-Viret, P.

    2013-01-01

    Roč. 1536, NOV 6 (2013), s. 144-158 ISSN 0006-8993 R&D Projects: GA ČR(CZ) GBP304/12/G069; GA ČR(CZ) GAP103/11/0282 Institutional support: RVO:67985823 Keywords : olfaction * spiking activity * neuronal model Subject RIV: JD - Computer Applications, Robotics Impact factor: 2.828, year: 2013

  1. The Influence of Antral Ulcers on Intramural Gastric Nerve Projections Supplying the Pyloric Sphincter in the Pig (Sus scrofa domestica-Neuronal Tracing Studies.

    Directory of Open Access Journals (Sweden)

    Michal Zalecki

    Full Text Available Gastric ulcerations in the region of antrum pylori represent a serious medical problem in humans and animals. Such localization of ulcers can influence the intrinsic descending nerve supply to the pyloric sphincter. The pyloric function is precisely regulated by intrinsic and extrinsic nerves. Impaired neural regulation could result in pyloric sphincter dysfunction and gastric emptying malfunction. The aim of the study was to determine the effect of gastric antral ulcerations on the density and distribution of intramural gastric descending neurons supplying the pyloric sphincter in pigs.The experiment was performed on 2 groups of pigs: healthy gilts (n=6 and gilts with experimentally induced peptic ulcers in the region of antrum pylori (n=6. Gastric neurons supplying pyloric sphincter were labeled using the retrograde neuronal tracing technique (20μl of Fast Blue tracer injected into the pyloric sphincter muscle. After a week survival period the animals were sacrificed and the stomachs were collected. Then, the stomach wall was cross-cut into 0.5cm thick sections taken in specified intervals (section I - 1.5cm; section II - 3.5cm; section III - 5.5cm; section IV - 7.5cm starting from the sphincter. Consecutive microscopic slices prepared from each section were analyzed under fluorescent microscope to count traced neurons. Obtained data were statistically analyzed. The total number of FB-positive perikarya observed within all studied sections significantly decreased from 903.3 ± 130.7 in control to 243.8 ± 67.3 in experimental animals. In healthy pigs 76.1 ± 6.7% of labeled neurons were observed within the section I, 23.53 ± 6.5% in section II and only occasional cells in section III. In experimental animals, as many as 93.8 ± 2.1% of labeled cells were observed within the section I and only 6.2 ± 2.2% in section II, while section III was devoid of such neurons. There were no traced perikarya in section IV observed in both groups of pigs

  2. Guidewires used in first intentional single wiring strategy for chronic total occlusions of the left anterior descending coronary artery.

    Science.gov (United States)

    Nassar, Yasser S; Boudou, Nicolas; Dumonteil, Nicolas; Lhermusier, Thibault; Carrie, Didier

    2013-04-01

    Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) of the left anterior descending (LAD) specifically is associated with improved long-term 5 year survival as compared to PCI failure. The procedure is associated with usage of different types of dedicated guidewires by simple or complex techniques aiming to reopen the occluded artery. To describe types and outcome of guidewires used in LAD-CTO utilizing a first intentional single wiring simple strategy. A single center prospective registry for all consecutive patients with a PCI attempt to a native LAD CTO. The initial strategy for lesion crossing was Single wiring. A total of 30 patients with LAD CTO lesions (100%), were recorded. Mean age was 71.6 + 15 years, 77% were Males, risk factors Hypertension in 63%, Diabetes 27%, Dyslipidemia 57%, smoking 40%, hereditary in 13% of patients. Isolated guidewire (GW) success rate was very high 93%. Single wiring was the prevailing technique used in 97% of successfull lesions (83% of total cases) while only 3% were by multiple wiring techniques. Successful single antegrade wiring represented 63% with a GW success rate of 92% of cases. Successful single retrograde wiring represented 13% with a GW success rate of 67%. Successful Crossing GW types in our patients were 44% Soft Tapered GWs; fielder XT (44%), 36% were Soft Non Tapered Pilot 50 (28%), whisper (8%), while 16% were Stiff Non tapered GWs; Miracle 12 (8%), Miracle 6 (4%), Miracle 3 (4%), and 4% were Stiff Tapered GWs; Progress 200 (4%). Single wiring as an initial strategy in PCI for LAD-CTO lesions has a high success rate and is associated with a 44% majority of Soft Tapered GWs, 36% Soft Non Tapered, 16% Stiff Non tapered GWs, and 4% Stiff Tapered GWs.

  3. Driving performance on the descending limb of blood alcohol concentration (BAC) in undergraduate students: a pilot study.

    Science.gov (United States)

    Tremblay, Mathieu; Gallant, François; Lavallière, Martin; Chiasson, Martine; Silvey, Dustin; Behm, David; Albert, Wayne J; Johnson, Michel J

    2015-01-01

    Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for young drivers to socially binge drink and decide to drive a vehicle a few hours after consumption. To better understand the risks that may be associated with this behaviour, the present study has examined the effects of a social drinking bout followed by a simulated drive in undergraduate students on the descending limb of their BAC (blood alcohol concentration) curve. Two groups of eight undergraduate students (n = 16) took part in this study. Participants in the alcohol group were assessed before drinking, then at moderate and low BAC as well as 24 hours post-acute consumption. This group consumed an average of 5.3 ± 1.4 (mean ± SD) drinks in an hour in a social context and were then submitted to a driving and a predicted crash risk assessment. The control group was assessed at the same time points without alcohol intake or social context.; at 8 a.m., noon, 3 p.m. and 8 a.m. the next morning. These multiple time points were used to measure any potential learning effects from the assessment tools (i.e. driving simulator and useful field of view test (UFOV)). Diminished driving performance at moderate BAC was observed with no increases in predicted crash risk. Moderate correlations between driving variables were observed. No association exists between driving variables and UFOV variables. The control group improved measures of selective attention after the third assessment. No learning effect was observed from multiple sessions with the driving simulator. Our results show that a moderate BAC, although legal, increases the risky behaviour. Effects of alcohol expectancy could have been displayed by the experimental group. UFOV measures and predicted crash risk categories were not sensitive enough to predict crash risk for young drivers, even when intoxicated.

  4. Fetal topographical anatomy of the female urethra and descending vagina: a histological study of the early human fetal urethra.

    Science.gov (United States)

    Masumoto, Hiroshi; Rodríguez-Vázquez, Jose Francisco; Verdugo-López, Samuel; Murakami, Gen; Matsubara, Akio

    2011-12-20

    Which parts of the male urethra correspond to the female urethra? To resolve this question, we need to understand fetal topographical changes in the urethra, its external sphincter and vagina. The vagina joins the mid-course of the primitive urethra and, later "descends" to the vaginal vestibulum. We examined histological sections of 14 female and 4 male mid-term fetuses. The inferior end of the vagina was consistently embedded in the posterior wall of the urethra at 9-12 weeks. The supero-inferior level of the vaginal merging was lower in larger fetuses. Thus, the sequential variation in levels appeared to reflect the process of vaginal descent. However, in spite of penetration of the vaginal end into the posterior urethral wall, we found no sign of destruction of the urethral wall after vaginal descent in the low-merging types. Before vaginal descent, the female external sphincter extended posterolaterally around the urethra. The vaginal descent is classically regarded as a relative topographical change, but it is likely to be a result of elongation of the proximal urethra in the superior side of the vaginal merging. Conversely, the distal urethra is likely to be incorporated into the vaginal vestibulum by 15 weeks. During these processes, most of the female external sphincter seems to be expelled from the original anterior position into the vestibular wall as the urethrovaginal sphincter. The adult female urethra seems to correspond to the male prostatic urethra superior to the prostatic colliculus. Copyright © 2011 Elsevier GmbH. All rights reserved.

  5. Epicardial mapping of ventricular fibrillation over the posterior descending artery and left posterior papillary muscle of the swine heart.

    Science.gov (United States)

    Nielsen, Thomas D; Huang, Jian; Rogers, Jack M; Killingsworth, Cheryl R; Ideker, Raymond E

    2009-01-01

    Recent studies suggest that during ventricular fibrillation (VF) epicardial vessels may be a site of conduction block and the posterior papillary muscle (PPM) in the left ventricle (LV) may be the location of a "mother rotor." The goal of this study was to obtain evidence to support or refute these possibilities. Epicardial activation over the posterior LV and right ventricle (RV) was mapped during the first 20 s of electrically induced VF in six open-chest pigs with a 504 electrode plaque covering a 20 cm(2) area centered over the posterior descending artery (PDA). The locations of epicardial breakthrough as well as reentry clustered in time and space during VF. Spatially, reentry occurred significantly more frequently over the LV than the RV in all 48 episodes, and breakthrough clustered near the PPM (p < 0.001). Significant temporal clustering occurred in 79% of breakthrough episodes and 100% of reentry episodes. These temporal clusters occurred at different times so that there was significantly less breakthrough when reentry was present (p < 0.0001). Conduction block occurred significantly more frequently near the PDA than elsewhere. The PDA is a site of epicardial block which may contribute to VF maintenance. Epicardial breakthrough clusters near the PPM. Reentry also clusters in space but at a separate site. The fact that breakthrough and reentry cluster at different locations and at different times supports the possibility of a drifting filament at the PPM so that at times reentry is present on the surface but at other times the reentrant wavefront breaks through to the epicardium.

  6. Why the 16th Century Spanish Conquistadors likely did not descend into Grand Canyon near Desert View: A new perspective

    Directory of Open Access Journals (Sweden)

    Ray Kenny

    2015-08-01

    Full Text Available There is probably no more historically significant or culturally pivotal event in the history of the south-western USA than the ambitious expedition of Francisco Vázquez de Coronado. Although the exploits of Coronado’s army have been examined for hundreds of years, new information has emerged from on-going studies of surviving documents and field work. This paper presents a new hypothesis and supportive evidence which suggest that a dispatch of Coronado’s men (led by Don Garcia López de Cárdenas with the goal of discovering the Colorado River, likely did not descend off the south rim of Grand Canyon near the present day Desert View area in eastern Grand Canyon, as proposed by Bartlett in 1940. Surviving documents indicate that the Cárdenas Expedition traveled 20 days and 130 miles before attempting a descent into the canyon; only three or four days of travel are needed to arrive at the Desert View area from the Hopi Village of Awat’ovi (the starting location of the Cárdenas expedition. In this paper, topographic, anthropologic and historic evidence along with new distance calculations are presented which suggest that the 16th Century Spanish descent into Grand Canyon did not occur near the present day Desert View area, but likely occurred at least 35 to 40 (linear miles west of this area near the present day South Bass Trail. Ramifications of the proposed hypothesis include: (1 focusing the search for Spanish artefacts and surviving evidence at a new location in western Grand Canyon; and, (2 rectifying the historical record.

  7. Detection of severe left anterior descending coronary artery stenosis by transthoracic evaluation of resting coronary flow velocity dynamics

    Directory of Open Access Journals (Sweden)

    Edward G. Abinader

    2010-09-01

    Full Text Available In the presence of severe stenosis, coronary artery flow may be reduced at rest. Recent advances in echocardiography have made non-invasive sampling of velocities in the left an­terior descending coronary artery (LAD possible. The aim of our study was to evaluate feasi­bility and capability of transthoracic Doppler to detect severe stenosis of the LAD. The study population consisted of 42 subjects with suspected coronary artery disease scheduled for coronary angiography. All had complete transthoracic echocardiography and Doppler sampling of LAD velocities. Quantitative cor­onary angiography was performed within 24 hours of the echocardiogram. Correlations between LAD velocity profile, measurements and calculations, and the angiographic results were performed. Six subjects had LAD occlusion, 10 had severe (>80% diameter LAD stenosis, and 26 had normal or non-occlusive LAD disease. In all six subjects with LAD occlusion, distal LAD velocities were not detectable, while in the other 36 subjects, LAD velocities were recorded indicating the vessels were patent. In the 10 subjects with severe LAD stenosis, the diastolic/systolic velocity ratio was <1.5, while in those with non-signifi­cant LAD disease, the diastolic/systolic velocity ratio was >1.5 (P<0.005. Diastolic LAD flow was 21.8±13 mL/min in the presence of severe stenosis as compared to 48.5±20 mL/min in subjects without severe stenosis (P<0.0013. LAD velocities had high sensitiv­ity and specificity for the prediction of severe angiographic stenosis. Thus transthoracic Doppler measurement of LAD velocities is feas­ible and can predict the presence of severe LAD stenosis or occlusion.

  8. Driving performance on the descending limb of blood alcohol concentration (BAC in undergraduate students: a pilot study.

    Directory of Open Access Journals (Sweden)

    Mathieu Tremblay

    Full Text Available Young drivers are overrepresented in collisions resulting in fatalities. It is not uncommon for young drivers to socially binge drink and decide to drive a vehicle a few hours after consumption. To better understand the risks that may be associated with this behaviour, the present study has examined the effects of a social drinking bout followed by a simulated drive in undergraduate students on the descending limb of their BAC (blood alcohol concentration curve. Two groups of eight undergraduate students (n = 16 took part in this study. Participants in the alcohol group were assessed before drinking, then at moderate and low BAC as well as 24 hours post-acute consumption. This group consumed an average of 5.3 ± 1.4 (mean ± SD drinks in an hour in a social context and were then submitted to a driving and a predicted crash risk assessment. The control group was assessed at the same time points without alcohol intake or social context.; at 8 a.m., noon, 3 p.m. and 8 a.m. the next morning. These multiple time points were used to measure any potential learning effects from the assessment tools (i.e. driving simulator and useful field of view test (UFOV. Diminished driving performance at moderate BAC was observed with no increases in predicted crash risk. Moderate correlations between driving variables were observed. No association exists between driving variables and UFOV variables. The control group improved measures of selective attention after the third assessment. No learning effect was observed from multiple sessions with the driving simulator. Our results show that a moderate BAC, although legal, increases the risky behaviour. Effects of alcohol expectancy could have been displayed by the experimental group. UFOV measures and predicted crash risk categories were not sensitive enough to predict crash risk for young drivers, even when intoxicated.

  9. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster.

    Science.gov (United States)

    Danjon, Frédéric; Caplan, Joshua S; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account for the fact that root systems are comprised of multiple types of roots. We assessed whether the relationship between CSD and Vd varies as a function of root type. Additionally, we sought to identify a more accurate and time-efficient method for estimating missing root volume than is currently available. We used a database that described the 3D root architecture of Pinus pinaster root systems (5, 12, or 19 years) from a stand in southwest France. We determined the relationship between CSD and Vd for 10,000 root segments from intact root branches. Models were specified that did and did not account for root type. The relationships were then applied to the diameters of 11,000 broken root ends to estimate the volume of missing roots. CSD was nearly linearly related to the square root of Vd, but the slope of the curve varied greatly as a function of root type. Sinkers and deep roots tapered rapidly, as they were limited by available soil depth. Distal shallow roots tapered gradually, as they were less limited spatially. We estimated that younger trees lost an average of 17% of root volume when excavated, while older trees lost 4%. Missing volumes were smallest in the central parts of root systems and largest in distal shallow roots. The slopes of the curves for each root type are synthetic parameters that account for differentiation due to genetics, soil properties, or mechanical stimuli. Accounting for this differentiation is critical to estimating root loss accurately.

  10. Mitogenomic and microsatellite variation in descendants of the founder population of Newfoundland: high genetic diversity in an historically isolated population.

    Science.gov (United States)

    Pope, A M; Carr, S M; Smith, K N; Marshall, H D

    2011-02-01

    The island of Newfoundland, the first of England's overseas colonies, was settled from the 17th century onward by restricted numbers of English, Irish, and French immigrants, in small "outport" communities that have maintained geographic, religious, and linguistic isolation to the latest generations. To measure the extent of modification and loss of genetic variation through founder effect, drift, and inbreeding in this historically isolated population, we analyzed the complete mitochondrial DNA (mtDNA) genomes and 14 microsatellite loci from each of 27 individuals with matrilineal ancestries extending to the colonial period. Every individual has a unique mtDNA genome sequence. All but one of these genomes are assignable to one of five major (H,J,K,T, and U) or minor (I) European haplogroups. The possibility of homoplasy at single nucleotide polymorphism (SNP) sites that define subtypes within the H haplogroup is discussed. Observed haplogroup proportions do not differ significantly from those of western Europeans or between English and Irish Newfoundlanders. The exceptional individual is a member of haplogroup A2, who appears to be the descendant of a Mi'kmaq First Nations mother and a French father, a common marriage pattern in the early settlement of Newfoundland. Microsatellite diversity is high (HE = 0.763), unstructured with respect to mtDNA haplotype or ethnicity, and there is no evidence of linkage disequilibrium. There is a small but significant degree of inbreeding (FIS = 0.0174). Collection of whole mtDNA genome data was facilitated by the use of microarray sequencing, and we describe a simple algorithm that is 99.67% efficient for sequence recovery.

  11. What We Know Currently about Mirror Neurons

    Science.gov (United States)

    Kilner, J.M.; Lemon, R.N.

    2013-01-01

    Mirror neurons were discovered over twenty years ago in the ventral premotor region F5 of the macaque monkey. Since their discovery much has been written about these neurons, both in the scientific literature and in the popular press. They have been proposed to be the neuronal substrate underlying a vast array of different functions. Indeed so much has been written about mirror neurons that last year they were referred to, rightly or wrongly, as “The most hyped concept in neuroscience”. Here we try to cut through some of this hyperbole and review what is currently known (and not known) about mirror neurons. PMID:24309286

  12. What we know currently about mirror neurons.

    Science.gov (United States)

    Kilner, J M; Lemon, R N

    2013-12-02

    Mirror neurons were discovered over twenty years ago in the ventral premotor region F5 of the macaque monkey. Since their discovery much has been written about these neurons, both in the scientific literature and in the popular press. They have been proposed to be the neuronal substrate underlying a vast array of different functions. Indeed so much has been written about mirror neurons that last year they were referred to, rightly or wrongly, as "The most hyped concept in neuroscience". Here we try to cut through some of this hyperbole and review what is currently known (and not known) about mirror neurons. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Oscillatory integration windows in neurons

    Science.gov (United States)

    Gupta, Nitin; Singh, Swikriti Saran; Stopfer, Mark

    2016-01-01

    Oscillatory synchrony among neurons occurs in many species and brain areas, and has been proposed to help neural circuits process information. One hypothesis states that oscillatory input creates cyclic integration windows: specific times in each oscillatory cycle when postsynaptic neurons become especially responsive to inputs. With paired local field potential (LFP) and intracellular recordings and controlled stimulus manipulations we directly test this idea in the locust olfactory system. We find that inputs arriving in Kenyon cells (KCs) sum most effectively in a preferred window of the oscillation cycle. With a computational model, we show that the non-uniform structure of noise in the membrane potential helps mediate this process. Further experiments performed in vivo demonstrate that integration windows can form in the absence of inhibition and at a broad range of oscillation frequencies. Our results reveal how a fundamental coincidence-detection mechanism in a neural circuit functions to decode temporally organized spiking. PMID:27976720

  14. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...... nerve were 50-60% reduced, whereas no definite changes occurred at lower doses. The SNAP conduction velocities were reduced by 10-15% at cumulative doses of 400-700 mg/m2 consistent with loss of large myelinated fibres. SNAPs from primarily Pacinian corpuscles in digit 3 and the dorsolateral side...... of large dorsal root ganglion cells. Motor conduction studies, autonomic function and warm and cold temperature sensation remained unchanged at all doses of cisplatin treatment. The results of these studies are consistent with degeneration of large sensory neurons whereas there was no evidence of distal...

  15. Spatially selective photoconductive stimulation of live neurons

    Directory of Open Access Journals (Sweden)

    Jacob eCampbell

    2014-05-01

    Full Text Available Synaptic activity is intimately linked to neuronal structure and function. Stimulation of live cultured primary neurons, coupled with fluorescent indicator imaging, is a powerful technique to assess the impact of synaptic activity on neuronal protein trafficking and function. Current technology for neuronal stimulation in culture include chemical techniques or microelectrode or optogenetic based techniques. While technically powerful, chemical stimulation has limited spatial resolution and microelectrode and optogenetic techniques require specialized equipment and expertise. We report an optimized and improved technique for laser based photoconductive stimulation of live neurons using an inverted confocal microscope that overcomes these limitations. The advantages of this approach include its non-invasive nature and adaptability to temporal and spatial manipulation. We demonstrate that the technique can be manipulated to achieve spatially selective stimulation of live neurons. Coupled with live imaging of fluorescent indicators, this simple and efficient technique should allow for significant advances in neuronal cell biology.

  16. Mirror Neurons from Associative Learning

    OpenAIRE

    Catmur, Caroline; Press, Clare; Heyes, Cecilia

    2016-01-01

    Mirror neurons fire both when executing actions and observing others perform similar actions. Their sensorimotor matching properties have generally been considered a genetic adaptation for social cognition; however, in the present chapter we argue that the evidence in favor of this account is not compelling. Instead we present evidence supporting an alternative account: that mirror neurons’ matching properties arise from associative learning during individual development. Notably, this proces...

  17. Neurons from the adult human dentate nucleus: neural networks in the neuron classification.

    Science.gov (United States)

    Grbatinić, Ivan; Marić, Dušica L; Milošević, Nebojša T

    2015-04-07

    Topological (central vs. border neuron type) and morphological classification of adult human dentate nucleus neurons according to their quantified histomorphological properties using neural networks on real and virtual neuron samples. In the real sample 53.1% and 14.1% of central and border neurons, respectively, are classified correctly with total of 32.8% of misclassified neurons. The most important result present 62.2% of misclassified neurons in border neurons group which is even greater than number of correctly classified neurons (37.8%) in that group, showing obvious failure of network to classify neurons correctly based on computational parameters used in our study. On the virtual sample 97.3% of misclassified neurons in border neurons group which is much greater than number of correctly classified neurons (2.7%) in that group, again confirms obvious failure of network to classify neurons correctly. Statistical analysis shows that there is no statistically significant difference in between central and border neurons for each measured parameter (p>0.05). Total of 96.74% neurons are morphologically classified correctly by neural networks and each one belongs to one of the four histomorphological types: (a) neurons with small soma and short dendrites, (b) neurons with small soma and long dendrites, (c) neuron with large soma and short dendrites, (d) neurons with large soma and long dendrites. Statistical analysis supports these results (pneurons can be classified in four neuron types according to their quantitative histomorphological properties. These neuron types consist of two neuron sets, small and large ones with respect to their perykarions with subtypes differing in dendrite length i.e. neurons with short vs. long dendrites. Besides confirmation of neuron classification on small and large ones, already shown in literature, we found two new subtypes i.e. neurons with small soma and long dendrites and with large soma and short dendrites. These neurons are

  18. Consciousness from neurons and waves

    Science.gov (United States)

    John, E. R.

    2004-05-01

    This paper presents a theory of consciousness based on the following evidence: [1] Complex stimuli are decomposed by the exogenous system into attributes transmitted to synapses of pyramidal neurons in lower cortical layers, encoding fragments of sensations as nonrandom synchronization that increases local voltages; [2] Endogenous readouts from representational systems encoding memories in a mesolimbic system are transmitted to synapses of the pyramidal neurons in upper layers; [3] Excitability of pyramidal neurons receiving convergent exogenous and endogenous inputs is enhanced, converting fragments of sensations to fragments of perception and creating high voltage islands of non-random synchrony; [4] Local Field Potential (LFP) oscillations are homeostatically regulated, imposing dynamically maintained local voltage thresholds that define a "Ground State" [5] Deviations from these most probable levels constitute local perturbations of entropy; [6] Modulation of cortex by LFPs, facilitating coherent cortico-thalamic (C-T) volleys of cells with suprathreshold excitability, binds dispersed fragments of local perturbations of entropy; [7] The thalamic cells from which convergence arose respond to these volleys by coherent T-C-T-C reverberations; [8] Sustained reverberation establishes a resonating electromagnetic field of information, the vehicle sustaining unified perception; [9] The resonating field of information constitutes Global Negative and generates the content of consciousness; [10] Invariant reversible LFP changes occur upon loss of consciousness and persistent shifts accompany many clinical disorders.

  19. Selective serotonergic excitation of callosal projection neurons

    Directory of Open Access Journals (Sweden)

    Daniel eAvesar

    2012-03-01

    Full Text Available Serotonin (5-HT acting as a neurotransmitter in the cerebral cortex is critical for cognitive function, yet how 5-HT regulates information processing in cortical circuits is not well understood. We tested the serotonergic responsiveness of layer 5 pyramidal neurons (L5PNs of the mouse medial prefrontal cortex (mPFC, and found 3 distinct response types: long-lasting 5-HT1A (1A receptor-dependent inhibitory responses (84% of L5PNs, 5-HT2A (2A receptor-dependent excitatory responses (9%, and biphasic responses in which 2A-dependent excitation followed brief inhibition (5%. Relative to 5-HT-inhibited neurons, those excited by 5-HT had physiological properties characteristic of callosal/commissural (COM neurons that project to the contralateral cortex. We tested whether serotonergic responses in cortical pyramidal neurons are correlated with their axonal projection pattern using retrograde fluorescent labeling of COM and corticopontine-projecting (CPn neurons. 5-HT generated excitatory or biphasic responses in all 5-HT-responsive layer 5 COM neurons. Conversely, CPn neurons were universally inhibited by 5-HT. Serotonergic excitation of COM neurons was blocked by the 2A antagonist MDL 11939, while serotonergic inhibition of CPn neurons was blocked by the 1A antagonist WAY 100635, confirming a role for these two receptor subtypes in regulating pyramidal neuron activity. Selective serotonergic excitation of COM neurons was not layer-specific, as COM neurons in layer 2/3 were also selectively excited by 5-HT relative to their non-labeled pyramidal neuron neighbors. Because neocortical 2A receptors are implicated in the etiology and pathophysiology of schizophrenia, we propose that COM neurons may represent a novel cellular target for intervention in psychiatric disease.

  20. Al otro lado del Atlántico. Los africanos y sus descencientes en Argentina /Across the Atlantic. Africans and their Descendants in Argentina

    Directory of Open Access Journals (Sweden)

    Diego Buffa

    2014-12-01

    Full Text Available El propósito de este trabajo es hacer un recorrido histórico, rastreando la presencia africana y afrodescendiente en el actual territorio argentino, desde el período colonial hasta la actualidad. Centraremos nuestro análisis en los momentos más significativos de su llegada, observando ciertos parámetros que las caracterizan y, al mismo tiempo, identificaremos patrones de marginación o exclusión social de los migrantes africanos y sus descendientes.The purpose of this work is to make a historical journey, tracing presence of Africans and Afro-descendants in the Argentinean territory, from the colonial period to the present. We focus our analysis on the most significant moments of their arrivals, observing certain parameters that characterize them and at the same time, identifying patterns of marginalization and social exclusion of African migrants and their descendants.

  1. Solutions of the Yang-Baxter equation: Descendants of the six-vertex model from the Drinfeld doubles of dihedral group algebras

    Energy Technology Data Exchange (ETDEWEB)

    Finch, P.E. [Centre for Mathematical Physics, School of Mathematics and Physics, University of Queensland, 4072 (Australia); Dancer, K.A., E-mail: dancer@maths.uq.edu.a [Centre for Mathematical Physics, School of Mathematics and Physics, University of Queensland, 4072 (Australia); Isaac, P.S.; Links, J. [Centre for Mathematical Physics, School of Mathematics and Physics, University of Queensland, 4072 (Australia)

    2011-06-11

    The representation theory of the Drinfeld doubles of dihedral groups is used to solve the Yang-Baxter equation. Use of the two-dimensional representations recovers the six-vertex model solution. Solutions in arbitrary dimensions, which are viewed as descendants of the six-vertex model case, are then obtained using tensor product graph methods which were originally formulated for quantum algebras. Connections with the Fateev-Zamolodchikov model are discussed.

  2. Small-scale modelling of cementation by descending silica-bearing fluids: Explanation of the origin of arenitic caves in South American tepuis

    Science.gov (United States)

    Aubrecht, R.; Lánczos, T.; Schlögl, J.; Audy, M.

    2017-12-01

    Geoscientific research was performed on South American table mountains (tepuis) and in their sandstone cave systems. To explain speleogenesis in these poorly soluble rocks, two theories were introduced: a) arenization theory implying selective weathering of quartz along grain boundaries and releasing of sand grains, b) selective lithification theory implying cementation by descending silica-bearing fluid flow. The latter theory presumes that the descending fluid flow becomes unstable on the interface between two layers with different porosity and splits to separate flow channels (so-called ;finger flow;). The arenites outside these channels remain uncemented. To verify the latter theory, small-scale modelling was performed, using layered sands and sodium-silicate solution. Fine to medium sand was used (0.08-0.5 mm), along with a coarse sand fraction (0.5-1.5 mm). The sands were layered and compacted in a transparent plastic boxes. Three liters of sodium-silicate solution (so-called water glass) were left to drip for several hours to the top of the sediment. The fine-grained layers were perfectly laterally impregnated, whereas the descending fluid flows split to ;fingers; in the coarse-grained layers due their higher hydraulic conductivity. This small-scale laboratory simulation mimics the real diagenesis by descending silica-bearing fluids and matches the real phenomena observed on the tepuis. The resulting cemented constructions closely mimic many geomorphological features observed on tepuis and inside their caves, e.g. ;finger-flow; pillars, overhangs, imperfectly formed (aborted) pillars in forms of hummocks hanging from ceilings, locally also thicker central pillars that originated by merging of smaller fluid-flow channels. The modelling showed that selective lithification theory can explain most of the geomorphological aspects related to the speleogenesis in tepuis.

  3. Dysregulation of the descending pain system in temporomandibular disorders revealed by low-frequency sensory transcutaneous electrical nerve stimulation: a pupillometric study.

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    Annalisa Monaco

    Full Text Available Using computerized pupillometry, our previous research established that the autonomic nervous system (ANS is dysregulated in patients suffering from temporomandibular disorders (TMDs, suggesting a potential role for ANS dysfunction in pain modulation and the etiology of TMD. However, pain modulation hypotheses for TMD are still lacking. The periaqueductal gray (PAG is involved in the descending modulation of defensive behavior and pain through μ, κ, and δ opioid receptors. Transcutaneous electrical nerve stimulation (TENS has been extensively used for pain relief, as low-frequency stimulation can activate µ receptors. Our aim was to use pupillometry to evaluate the effect of low-frequency TENS stimulation of μ receptors on opioid descending pathways in TMD patients. In accordance with the Research Diagnostic Criteria for TMD, 18 females with myogenous TMD and 18 matched-controls were enrolled. All subjects underwent subsequent pupillometric evaluations under dark and light conditions before, soon after (end of stimulation and long after (recovery period sensorial TENS. The overall statistics derived from the darkness condition revealed no significant differences in pupil size between cases and controls; indeed, TENS stimulation significantly reduced pupil size in both groups. Controls, but not TMD patients, displayed significant differences in pupil size before compared with after TENS. Under light conditions, TMD patients presented a smaller pupil size compared with controls; the pupil size was reduced only in the controls. Pupil size differences were found before and during TENS and before and after TENS in the controls only. Pupillometry revealed that stimulating the descending opioid pathway with low-frequency sensory TENS of the fifth and seventh pairs of cranial nerves affects the peripheral target. The TMD patients exhibited a different pattern of response to TENS stimulation compared with the controls, suggesting that impaired

  4. Origins location of the outflow tract ventricular arrhythmias exhibiting qrS pattern or QS pattern with a notch on the descending limb in lead V1.

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    Lin, Cong; Zheng, Cheng; Zhou, De-Pu; Li, Xiao-Wei; Wu, Shu-Jie; Lin, Jia-Feng

    2017-05-15

    Ventricular outflow tract(VOT) ventricular arrhythmias(VAs) presenting qrS pattern or QS pattern with a notch on the descending limb in lead V1 were consistently thought of arising from the commissure between left and right coronary cusp (L-RCC) by previous studies. However, we found they could originate from other anatomic structures in VOT. This study aimed to investigate the exact origin of this kind VAs. Forty-nine patients of VOT premature ventricular contrations/ventricular tachycardia(PVCs/VT) with lead V1 presenting qrS pattern or QS pattern with a notch on the descending limb undergoing successful radiofrequency catheter ablation(RFCA) in our center were analyzed. 12-lead electrocardiogram(ECG) of these PVCs/VT were summarized. Among these PVCs/VT, 37 cases exhibited qrS morphology in lead V1, 12 cases presented QS pattern with a notch on the descending limb in the same lead. Based on the successful ablation sites, these PVCs/VT were divided into 2 groups: (1)Right ventricular outflow tract(RVOT) group (26 cases), and (2) Left ventricular outflow tract (LVOT) group(23 cases, 4 cases originating from the left coronary cusp(LCC), 2 from the right coronary cusp(RCC), 16 from the L-RCC, 1 from the area inferior to LCC(ILCC)). The ECG characteristics of each PVCs/VT were analyzed. Among these PVCs/VT, applying the precordial transitional zone index(TZ index) pattern or QS pattern with a notch on descending limb not only arising from L-RCC, but also RVOT, LCC, RCC and ILCC. Combining TZ index and QRS morphology in lead I to predict origin site of these kind VAs is a convenient, simple and reliable method and facilitates the RFCA procedure.

  5. Coronary heart disease clinical manifestation and risk factors in Japanese immigrants and their descendents in the city of São Paulo

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    Amato Reynaldo Vicente

    2003-01-01

    Full Text Available OBJECTIVE: To assess whether a difference exists in coronary heart disease clinical manifestations and the prevalence of risk factors between Japanese immigrants and their descendents in the city of São Paulo. METHODS: Retrospective analysis of coronary artery disease clinical manifestations and the prevalence of risk factors, comparing 128 Japanese immigrants (Japanese group with 304 Japanese descendents (Nisei group. RESULTS: The initial manifestation of the disease was earlier in the Nisei group (mean = 53 years, a difference of 12 years when compared with that in the Japanese group (mean = 65 years (P<0.001. Myocardial infarction was the first manifestation in both groups (P = 0.83. The following parameters were independently associated with early coronary events: smoking (OR = 2.25; 95% CI = 1.35-3.77; P<0.002; Nisei group (OR = 10.22; 95% CI = 5.64-18.5; P<0.001; and female sex (OR = 5.04; 95% CI = 2.66-9.52; P<0.001. CONCLUSION: The clinical presentation of coronary heart disease in the Japanese and their descendents in the city of São Paulo was similar, but coronary heart disease onset occurred approximately 12 years earlier in the Nisei group than in the Japanese group.

  6. Paraplegia of Lower Limbs Caused By A Segmental Thrombosis of the Descending Thoracic Aorta Reversed With Endovascular Treatment - A Case Report And Literature Review.

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    Diamante Leiderman, Dafne Braga; Wolosker, Nelson; Vieira de Melo Oliveira, Marcos; Miranda de Carvalho, Heitor Andrei; Trajano de Freitas Barão, Felipe; Zerati, Antonio Eduardo; De Luccia, Nelson; Puech-Leão, Pedro

    2018-03-05

    Transient paraplegia of the lower limbs is a rare condition and when has a vascular etiology is usually associated with thromboembolic events, aortic dissection, aortic aneurysms, or as a complication of the surgical correction of those deseases. There is no case reported of acute paraplegia caused by a segmental thrombotic subocclusion of the descending thoracic aorta. We report a not yet described clinical situation of a young patient (51 years) admitted to the emergency care department for treatment of systemic arterial hypertension of difficult control with 4 antihypertensive medication classes. At the intensive care unit for treatment with intravenous antihypertensive, evolved with acute paraplegia and a segmental thrombotic subocclusion of the descending thoracic aorta, previously free of disease, was diagnosed. He was submitted to endovascular treatment with total recovery of the deficits. The previously normal descending thoracic aorta may be a site of segmental thrombosis and may lead to paraplegia. Early endovascular treatment can reverse this type of situation. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Simultaneous multi-vessel coronary artery bypass grafting, ischemic mitral regurgitation repair and descending aortic aneurysm replacement: analysis of technical points.

    Science.gov (United States)

    Malyshev, Michael; Safuanov, Alexander; Borovikov, Dmitry; Malyshev, Anton

    2008-04-01

    The combination of coronary artery disease and its complications (ischemic mitral regurgitation etc.) with the aneurysm of the descending thoracic aorta is not a rare case. The single-stage correction of coronary/intracardiac/aortic lesions may be considered as a way of managing the combined patients. Simultaneous multi-vessel coronary artery bypass grafting, suture mitral annuloplasty and descending aortic aneurysm replacement with synthetic prosthesis is described. The operation was performed through the left thoracotomy with cardiopulmonary bypass established by the cannulation of the ascending aorta and of the right atrial appendage. Ventricular fibrillation and no clamping of the ascending aorta were used. The circulatory arrest was induced for the construction of the proximal anastomosis between the descending aorta and the synthetic prosthesis. No complications related to the operation were diagnosed for the 14-month follow-up. Several technical points seem optimal for the combined procedure: (1) Minimization of manipulations on the ascending aorta (using of pedicled left internal thoracic artery; construction of the proximal anastomoses with synthetic aortic prosthesis; unclamped ascending aorta). (2) Revascularization of all coronary areas and correction of intracardiac lesions through the left thoracotomy. Individual planning of the procedural technical points for every patient may provide a safe feasibility of the combined procedure.

  8. The Efficacy of the Coaxial Technique Using a 6-Fr Introducer Sheath in Stent Placement for Treating the Obstructions Proximal to the Descending Colon

    International Nuclear Information System (INIS)

    Chang, Il Soo; Park, Sang Woo; Hwang, Dae Yong; Seong, Moo Kyung; Joh, Hee Kyung; Yoon, So Young; Cho, Yo Han; Choe, Won Hyeok

    2011-01-01

    We wanted to evaluate the efficacy of stent placement using the coaxial technique with a stiff, long introducer sheath in patients with technical failure using an angiographic catheter for the obstructions proximal to the descending colon. Self-expandable metallic stent placement was attempted under fluoroscopy-guidance in 77 consecutive patients who had malignant colorectal obstruction. Stent placement was performed using an angiographic catheter and a guide wire. If the angiographic catheter could not be advanced over the guide wire into the obstructive lesions proximal to the descending colon, then a 6-Fr introducer sheath was used. The technical success rate, the clinical success rate and the complications were analyzed. Successful stent placement was achieved in 75 of 77 patients (97%). The angiographic catheter failed to advance into the obstructive lesions of 11 patients (M:F = 7:4: mean age, 65.5 years) whose lesions were at the level of the splenic flexure or transverse colon. Therefore, the coaxial technique was implemented in all these 11 patients using a 6-Fr stiff introducer sheath and then the stent placement was successful. There were no complications related to the use of a stiff introducer sheath. Clinical success, which was defined as relief of clinical obstructive bowel symptoms, was obtained within 24 hours in all of patients. The coaxial technique using a stiff introducer sheath can increase the technical success of fluoroscopy-guided, self-expandable metallic stent placement in patients with colonic obstruction proximal to the descending colon

  9. Motor neurons and the generation of spinal motor neurons diversity

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    Nicolas eStifani

    2014-10-01

    Full Text Available Motor neurons (MNs are neuronal cells located in the central nervous system (CNS controlling a variety of downstream targets. This function infers the existence of MN subtypes matching the identity of the targets they innervate. To illustrate the mechanism involved in the generation of cellular diversity and the acquisition of specific identity, this review will focus on spinal motor neurons (SpMNs that have been the core of significant work and discoveries during the last decades. SpMNs are responsible for the contraction of effector muscles in the periphery. Humans possess more than 500 different skeletal muscles capable to work in a precise time and space coordination to generate complex movements such as walking or grasping. To ensure such refined coordination, SpMNs must retain the identity of the muscle they innervate.Within the last two decades, scientists around the world have produced considerable efforts to elucidate several critical steps of SpMNs differentiation. During development, SpMNs emerge from dividing progenitor cells located in the medial portion of the ventral neural tube. MN identities are established by patterning cues working in cooperation with intrinsic sets of transcription factors. As the embryo develop, MNs further differentiate in a stepwise manner to form compact anatomical groups termed pools connecting to a unique muscle target. MN pools are not homogeneous and comprise subtypes according to the muscle fibers they innervate.This article aims to provide a global view of MN classification as well as an up-to-date review of the molecular mechanisms involved in the generation of SpMN diversity. Remaining conundrums will be discussed since a complete understanding of those mechanisms constitutes the foundation required for the elaboration of prospective MN regeneration therapies.

  10. Central Projection of Antennal Sensory Neurons in the Central Nervous System of the Mirid Bug Apolygus lucorum (Meyer-Dür).

    Science.gov (United States)

    Xie, Gui-Ying; Zhao, Xin-Cheng; Ma, Bai-Wei; Guo, Pei; Li, Guo-Ping; Feng, Hong-Qiang; Wu, Guo-Liang

    2016-01-01

    The mirid bug Apolygus lucorum (Meyer-Dür), a polyphagous pest, is dependent on olfactory cues to locate various host plant species and mates. In this study, we traced the projection pathway of the antennal sensory neurons and visualized their projection patterns in the central nervous system of A. lucorum through confocal microscopy and digital reconstructions. We also examined the glomerular organization of the primary olfactory center of the brain, the antennal lobe, and created a three-dimensional model of the glomeruli. We found that the axons of the sensory neurons project into the brain via the ipsilateral antennal nerve, and descend further into the gnathal ganglion, prothoracic ganglion, mesothoracic ganglion, and metathoracic ganglion, and reach as far as to the abdominal ganglion. Such a projection pattern indicates that antennal sensory neurons of A. lucorum may be potentially directly connected to motor neurons. The antennal lobe, however, is the major target area of antennal sensory neurons. The antennal lobe is composed of a large number of glomeruli, i.e. 70-80 glomeruli in one AL of A. lucorum. The results of this study which provide information about the basic anatomical arrangement of the brain olfactory center of A. lucorum, are important for further investigations of chemosensory encoding mechanisms of the mirid bug.

  11. Central Projection of Antennal Sensory Neurons in the Central Nervous System of the Mirid Bug Apolygus lucorum (Meyer-Dür.

    Directory of Open Access Journals (Sweden)

    Gui-Ying Xie

    Full Text Available The mirid bug Apolygus lucorum (Meyer-Dür, a polyphagous pest, is dependent on olfactory cues to locate various host plant species and mates. In this study, we traced the projection pathway of the antennal sensory neurons and visualized their projection patterns in the central nervous system of A. lucorum through confocal microscopy and digital reconstructions. We also examined the glomerular organization of the primary olfactory center of the brain, the antennal lobe, and created a three-dimensional model of the glomeruli. We found that the axons of the sensory neurons project into the brain via the ipsilateral antennal nerve, and descend further into the gnathal ganglion, prothoracic ganglion, mesothoracic ganglion, and metathoracic ganglion, and reach as far as to the abdominal ganglion. Such a projection pattern indicates that antennal sensory neurons of A. lucorum may be potentially directly connected to motor neurons. The antennal lobe, however, is the major target area of antennal sensory neurons. The antennal lobe is composed of a large number of glomeruli, i.e. 70-80 glomeruli in one AL of A. lucorum. The results of this study which provide information about the basic anatomical arrangement of the brain olfactory center of A. lucorum, are important for further investigations of chemosensory encoding mechanisms of the mirid bug.

  12. Radial approach and single wiring as first intentional strategies in chronic total occlusions of the left anterior descending coronary artery.

    Science.gov (United States)

    Nassar, Yasser; Boudou, Nicolas; Carrie, Didier

    2013-04-01

    Percutaneous coronary intervention (PCI) for chronic total occlusion (CTO) of the left anterior descending coronary artery (LAD) specifically is associated with improved long-term 5 years survival as compared to PCI failure. Simpler PCI techniques may be successful and safer than complex techniques which are perceived to have high failure rates and technical complexity. We aimed to describe the safety and effectiveness of first intentional single wiring and radial approach in the treatment of patients with a CTO of the native LAD coronary artery at Toulouse Rangueil university hospitals. The study was a single center prospective registry. All patients showed evidence of myocardial viability in LAD territory. The operators' initial strategy was to start by a radial access as a first choice whenever feasible; if not, a femoral access was chosen. The initial strategy for lesion crossing in either antegrade or retrograde approaches was single wiring by lesion crossing using one guidewire (GW) as a simple technique. A total of 30 patients with 30 LAD CTO lesions (100%) were recorded. Mean age was 71.6 + 15 years, 77% were males and 23% were females. The access route was radial 66% of the time and femoral 54% of the time and with double access for contralateral injection in 40% of the patients. Sheaths and catheters sizes 6F were used in 53% of the patients, and 7F in 73% of the patients. Overall lesion success rate was 83% of lesions. Single wiring was the prevailing technique used in 97% of successful lesions (83% of total cases), while only 3% were by multiple wiring techniques. Successful single antegrade wiring represented 63% of our total study cases with a GW success rate of 92% of cases. Successful single retrograde wiring represented 13% of our cases with a GW success rate of 67%. Q-wave myocardial infarction (MI), stent thrombosis, stroke, emergency coronary artery bypass graft (CABG), major bleeding, radiation dermatitis, cardiac tamponade or clinical

  13. Pre-Hospital 12-Lead Electrocardiogram within 60 Minutes Differentiates Proximal versus Nonproximal Left Anterior Descending Artery Myocardial Infarction

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    James J McCarthy

    2011-05-01

    Full Text Available Introduction: Acute anterior myocardial infarctions caused by proximal left anterior descending (LAD artery occlusions are associated with a higher morbidity and mortality. Early identification of high-risk patients via the 12-lead electrocardiogram (ECG could assist physicians and emergency response teams in providing early and aggressive care for patients with anterior ST-elevation myocardial infarctions (STEMI. Approximately 25% of US hospitals have primary percutaneous coronary intervention (PCI capability for the treatment of acute myocardial infarctions. Given the paucity of hospitals capable of PCI, early identification of more severe myocardial infarction may prompt emergency medical service routing of these patients to PCI-capable hospitals. We sought to determine if the 12 lead ECG is capable of predicting proximal LAD artery occlusions. Methods: In a retrospective, post-hoc analysis of the Pre-Hospital Administration of Thrombolytic Therapy with Urgent Culprit Artery Revascularization pilot trial, we compared the ECG findings of proximal and nonproximal LAD occlusions for patients who had undergone an ECG within 180 minutes of symptom onset. Results: In this study, 72 patients had anterior STEMIs, with ECGs performed within 180 minutes of symptom onset. In patients who had undergone ECGs within 60 minutes (n¼35, the mean sum of ST elevation (STE in leads V1 through V6 plus ST depression (STD in leads II, III, and aVF was 19.2 mm for proximal LAD occlusions and 11.7 mm for nonproximal LAD occlusions (P¼0.007. A sum STE in V1 through V6 plus STD in II, III, and aVF of at least 17.5 mm had a sensitivity of 52.3%, specificity of 92.9%, positive predictive value of 91.7%, and negative predictive value of 56.5% for proximal LAD occlusions. When the ECG was performed more than 60 minutes after symptom onset (n¼37, there was no significant difference in ST-segment deviation between the 2 groups. Conclusion: The sum STE (V1-V6 and STD (II

  14. Attenuation of cortical activity triggering descending pain inhibition in chronic low back pain patients: a functional magnetic resonance imaging study.

    Science.gov (United States)

    Matsuo, Yohei; Kurata, Jiro; Sekiguchi, Miho; Yoshida, Katsuhiro; Nikaido, Takuya; Konno, Shin-Ichi

    2017-08-01

    LBP group, which was negatively correlated with higher MPQ scores. The cLBP patients showed attenuated reactivity to pain at the ACC and DLPFC, known cortical areas mediating affective component, and top-down modulation, of pain. The present results might be associated with possible dysfunction of the descending pain inhibitory system in patients with chronic low back pain, which might possibly play a role in chronification of pain.

  15. Early and late outcomes of open repair for dissecting aneurysms of the descending or thoraco-abdominal aorta.

    Science.gov (United States)

    Omura, Atsushi; Minatoya, Kenji; Matsuo, Jiro; Inoue, Yosuke; Seike, Yoshimasa; Uehara, Kyokun; Sasaki, Hiroaki; Matsuda, Hitoshi; Kobayashi, Junjiro

    2017-10-09

    Although open repair is the standard surgical option for dissecting descending thoracic aneurysms (DTAs) and thoraco-abdominal aorta aneurysms (TAAAs), it remains a significant challenge with considerable perioperative morbidity and mortality. We retrospectively analysed early and late outcomes of open repair for these aortic aneurysms. Early and late outcomes were investigated for 223 consecutive patients who underwent open repair for dissecting DTA or TAAA between January 2003 and December 2014 (mean age 55 ± 16 years). The basic strategy for open surgery comprised liberal use of deep hypothermia and aggressive preservation or reattachment of intercostal arteries, i.e. donor arteries for the artery of Adamkiewicz. Deep hypothermia was used in 150 (67.3%) patients. The overall in-hospital mortality rate was 3.6% and 1.5% for elective cases. The rates of spinal cord ischaemic injury and stroke were 3.1% and 4.5%, respectively. During follow-up (mean 63 ± 40 months), overall 5-year survival rates was 89.2 ± 2.4% and 91.3 ± 2.8% and 86.3 ± 4.1% for DTA and TAAA, respectively. Five- and 10-year rates of freedom from aortic events, defined as surgery for initial operation-related events or for downstream aortic dilation, were 89.1 ± 3.5% and 68.2 ± 7.8% for DTA and 100% and 96.6 ± 3.4% for TAAA, respectively (P < 0.01). Our approach in treating this aortic pathology showed favourable early and long-term outcomes with acceptable neurological complication rates. More careful follow-up is necessary in patients with DTA repair, because downstream aortic enlargement occurs in some patients. © The Author 2017. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

  16. Sparing of descending axons rescues interneuron plasticity in the lumbar cord to allow adaptive learning after thoracic spinal cord injury

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    Christopher Nelson Hansen

    2016-03-01

    Full Text Available This study evaluated the role of spared axons on structural and behavioral neuroplasticity in the lumbar enlargement after a thoracic spinal cord injury (SCI. Previous work has demonstrated that recovery in the presence of spared axons after an incomplete lesion increases behavioral output after a subsequent complete spinal cord transection (TX. This suggests that spared axons direct adaptive changes in below-level neuronal networks of the lumbar cord. In response to spared fibers, we postulate that lumbar neuron networks support behavioral gains by preventing aberrant plasticity. As such, the present study measured histological and functional changes in the isolated lumbar cord after complete TX or incomplete contusion (SCI. To measure functional plasticity in the lumbar cord, we used an established instrumental learning paradigm. In this paradigm, neural circuits within isolated lumbar segments demonstrate learning by an increase in flexion duration that reduces exposure to a noxious leg shock. We employed this model using a proof-of-principle design to evaluate the role of sparing on lumbar learning and plasticity early (7 days or late (42 days after midthoracic SCI in a rodent model. Early after SCI or TX at 7d, spinal learning was unattainable regardless of whether the animal recovered with or without axonal substrate. Failed learning occurred alongside measures of cell soma atrophy and aberrant dendritic spine expression within interneuron populations responsible for sensorimotor integration and learning. Alternatively, exposure of the lumbar cord to a small amount of spared axons for 6 weeks produced near-normal learning late after SCI. This coincided with greater cell soma volume and fewer aberrant dendritic spines on interneurons. Thus, an opportunity to influence activity-based learning in locomotor networks depends on spared axons limiting maladaptive plasticity. Together, this work identifies a time dependent interaction between

  17. [Effects of flow-through descending branch of lateral circumflex femoral artery flap on repairing high-voltage electrical burn wounds of wrist of patients].

    Science.gov (United States)

    Shen, Y M; Chen, X; Zhang, C; Wang, C; Qin, F J; Ma, C X; Hu, X H

    2017-07-20

    Objective: To investigate the effects of flow-through descending branch of lateral circumflex femoral artery flap on repairing high-voltage electrical burn wounds of wrist of patients. Methods: From January 2014 to June 2016, 5 patients with high-voltage electrical burn of unilateral wrist were hospitalized in our burn ward, with extensive necrosis of skin soft tissue of burn wrist. Five patients were transferred to our burn ward 6 to 12 days post injury after undergoing emergency dermotomy of wrist to reduce tension in other hospitals. In 2 to 3 days after admission, operation was performed by two surgeon group at the same time, when patients' general condition were stable. One group underwent debridement and the other group designed and dissected flap according to the range of skin soft tissue defect of wrist. Wrist wounds after debridement ranged from 15 cm×10 cm to 24 cm×15 cm. Three patients were treated with flow-through descending branch of lateral circumflex femoral artery flap and great saphenous vein for repairing wounds of wrist and reconstruction of ulnar and radial artery. Two patients were treated with flow-through descending branch of lateral circumflex femoral artery flap for repairing wounds of wrist and reconstruction of ulnar artery. The dissected flaps ranged from 16 cm×12 cm to 26 cm×16 cm and the length of bridging vessel ranged from 15 to 21 cm. Results: The flow-through descending branch of lateral circumflex femoral artery flaps of five patients survived well. Wounds of 4 patients healed and wounds of 1 patient with infection under the flap on 3 days after operation healed after changing wound dressing and undergoing debridement for 2 weeks. After the operation, wrists and hands of 5 patients had adequate blood supply and ulnar and radial artery recovered patency. Follow-up of patients for 6 months to 1 year showed good flap appearance and adequate blood supply of burn hands. Conclusions: The flow-through descending branch of lateral

  18. Presynaptic Glycine Receptors Increase GABAergic Neurotransmission in Rat Periaqueductal Gray Neurons

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    Kwi-Hyung Choi

    2013-01-01

    Full Text Available The periaqueductal gray (PAG is involved in the central regulation of nociceptive transmission by affecting the descending inhibitory pathway. In the present study, we have addressed the functional role of presynaptic glycine receptors in spontaneous glutamatergic transmission. Spontaneous EPSCs (sEPSCs were recorded in mechanically dissociated rat PAG neurons using a conventional whole-cell patch recording technique under voltage-clamp conditions. The application of glycine (100 µM significantly increased the frequency of sEPSCs, without affecting the amplitude of sEPSCs. The glycine-induced increase in sEPSC frequency was blocked by 1 µM strychnine, a specific glycine receptor antagonist. The results suggest that glycine acts on presynaptic glycine receptors to increase the probability of glutamate release from excitatory nerve terminals. The glycine-induced increase in sEPSC frequency completely disappeared either in the presence of tetrodotoxin or Cd2+, voltage-gated Na+, or Ca2+ channel blockers, suggesting that the activation of presynaptic glycine receptors might depolarize excitatory nerve terminals. The present results suggest that presynaptic glycine receptors can regulate the excitability of PAG neurons by enhancing glutamatergic transmission and therefore play an important role in the regulation of various physiological functions mediated by the PAG.

  19. A Radial Glia Fascicle Leads Principal Neurons from the Pallial-Subpallial Boundary into the Developing Human Insula

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    Emilio González-Arnay

    2017-12-01

    Full Text Available The human insular lobe, in the depth of the Sylvian fissure, displays three main cytoarchitectonic divisions defined by the differentiation of granular layers II and IV. These comprise a rostro-ventral agranular area, an intermediate dysgranular area, and a dorso-caudal granular area. Immunohistochemistry in human embryos and fetuses using antibodies against PCNA, Vimentin, Nestin, Tbr1, and Tb2 reveals that the insular cortex is unique in that it develops far away from the ventricular zone (VZ, with most of its principal neurons deriving from the subventricular zone (SVZ of the pallial-subpallial boundary (PSB. In human embryos (Carnegie stage 16/17, the rostro-ventral insula is the first cortical region to develop; its Tbr1+ neurons migrate from the PSB along the lateral cortical stream. From 10 gestational weeks (GW onward, lateral ventricle, ganglionic eminences, and PSB grow forming a C-shaped curvature. The SVZ of the PSB gives rise to a distinct radial glia fiber fascicle (RGF, which courses lateral to the putamen in the external capsule. In the RGF, four components can be established: PF, descending from the prefrontal PSB to the anterior insula; FP, descending from the fronto-parietal PSB toward the intermediate insula; PT, coursing from the PSB near the parieto-temporal junction to the posterior insula, and T, ascending from the temporal PSB and merging with components FP and PT. The RGF fans out at different dorso-ventral and rostro-caudal levels of the insula, with descending fibers predominating over ascending ones. The RGF guides migrating principal neurons toward the future agranular, dysgranular, and granular insular areas, which show an adult-like definition at 32 GW. Despite the narrow subplate, and the absence of an intermediate zone except in the caudal insula, most insular subdivisions develop into a 6-layered isocortex, possibly due to the well developed outer SVZ at the PSB, which is particularly prominent at the level of

  20. Neuronal Networks on Nanocellulose Scaffolds.

    Science.gov (United States)

    Jonsson, Malin; Brackmann, Christian; Puchades, Maja; Brattås, Karoline; Ewing, Andrew; Gatenholm, Paul; Enejder, Annika

    2015-11-01

    Proliferation, integration, and neurite extension of PC12 cells, a widely used culture model for cholinergic neurons, were studied in nanocellulose scaffolds biosynthesized by Gluconacetobacter xylinus to allow a three-dimensional (3D) extension of neurites better mimicking neuronal networks in tissue. The interaction with control scaffolds was compared with cationized nanocellulose (trimethyl ammonium betahydroxy propyl [TMAHP] cellulose) to investigate the impact of surface charges on the cell interaction mechanisms. Furthermore, coatings with extracellular matrix proteins (collagen, fibronectin, and laminin) were investigated to determine the importance of integrin-mediated cell attachment. Cell proliferation was evaluated by a cellular proliferation assay, while cell integration and neurite propagation were studied by simultaneous label-free Coherent anti-Stokes Raman Scattering and second harmonic generation microscopy, providing 3D images of PC12 cells and arrangement of nanocellulose fibrils, respectively. Cell attachment and proliferation were enhanced by TMAHP modification, but not by protein coating. Protein coating instead promoted active interaction between the cells and the scaffold, hence lateral cell migration and integration. Irrespective of surface modification, deepest cell integration measured was one to two cell layers, whereas neurites have a capacity to integrate deeper than the cell bodies in the scaffold due to their fine dimensions and amoeba-like migration pattern. Neurites with lengths of >50 μm were observed, successfully connecting individual cells and cell clusters. In conclusion, TMAHP-modified nanocellulose scaffolds promote initial cellular scaffold adhesion, which combined with additional cell-scaffold treatments enables further formation of 3D neuronal networks.

  1. A chimeric path to neuronal synchronization

    Energy Technology Data Exchange (ETDEWEB)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L. [School of Biological and Health Systems Engineering, Arizona State University, Tempe, Arizona 85287-9709 (United States)

    2015-01-15

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an “all or none” phenomenon, but can pass through an intermediate stage (chimera)

  2. A chimeric path to neuronal synchronization

    International Nuclear Information System (INIS)

    Essaki Arumugam, Easwara Moorthy; Spano, Mark L.

    2015-01-01

    Synchronization of neuronal activity is associated with neurological disorders such as epilepsy. This process of neuronal synchronization is not fully understood. To further our understanding, we have experimentally studied the progression of this synchronization from normal neuronal firing to full synchronization. We implemented nine FitzHugh-Nagumo neurons (a simplified Hodgkin-Huxley model) via discrete electronics. For different coupling parameters (synaptic strengths), the neurons in the ring were either unsynchronized or completely synchronized when locally coupled in a ring. When a single long-range connection (nonlocal coupling) was introduced, an intermediate state known as a chimera appeared. The results indicate that (1) epilepsy is likely not only a dynamical disease but also a topological disease, strongly tied to the connectivity of the underlying network of neurons, and (2) the synchronization process in epilepsy may not be an “all or none” phenomenon, but can pass through an intermediate stage (chimera)

  3. Morphological Neuron Classification Using Machine Learning

    Science.gov (United States)

    Vasques, Xavier; Vanel, Laurent; Villette, Guillaume; Cif, Laura

    2016-01-01

    Classification and quantitative characterization of neuronal morphologies from histological neuronal reconstruction is challenging since it is still unclear how to delineate a neuronal cell class and which are the best features to define them by. The morphological neuron characterization represents a primary source to address anatomical comparisons, morphometric analysis of cells, or brain modeling. The objectives of this paper are (i) to develop and integrate a pipeline that goes from morphological feature extraction to classification and (ii) to assess and compare the accuracy of machine learning algorithms to classify neuron morphologies. The algorithms were trained on 430 digitally reconstructed neurons subjectively classified into layers and/or m-types using young and/or adult development state population of the somatosensory cortex in rats. For supervised algorithms, linear discriminant analysis provided better classification results in comparison with others. For unsupervised algorithms, the affinity propagation and the Ward algorithms provided slightly better results. PMID:27847467

  4. Performance limitations of relay neurons.

    Directory of Open Access Journals (Sweden)

    Rahul Agarwal

    Full Text Available Relay cells are prevalent throughout sensory systems and receive two types of inputs: driving and modulating. The driving input contains receptive field properties that must be transmitted while the modulating input alters the specifics of transmission. For example, the visual thalamus contains relay neurons that receive driving inputs from the retina that encode a visual image, and modulating inputs from reticular activating system and layer 6 of visual cortex that control what aspects of the image will be relayed back to visual cortex for perception. What gets relayed depends on several factors such as attentional demands and a subject's goals. In this paper, we analyze a biophysical based model of a relay cell and use systems theoretic tools to construct analytic bounds on how well the cell transmits a driving input as a function of the neuron's electrophysiological properties, the modulating input, and the driving signal parameters. We assume that the modulating input belongs to a class of sinusoidal signals and that the driving input is an irregular train of pulses with inter-pulse intervals obeying an exponential distribution. Our analysis applies to any [Formula: see text] order model as long as the neuron does not spike without a driving input pulse and exhibits a refractory period. Our bounds on relay reliability contain performance obtained through simulation of a second and third order model, and suggest, for instance, that if the frequency of the modulating input increases or the DC offset decreases, then relay increases. Our analysis also shows, for the first time, how the biophysical properties of the neuron (e.g. ion channel dynamics define the oscillatory patterns needed in the modulating input for appropriately timed relay of sensory information. In our discussion, we describe how our bounds predict experimentally observed neural activity in the basal ganglia in (i health, (ii in Parkinson's disease (PD, and (iii in PD during

  5. Neurosemantics, neurons and system theory.

    Science.gov (United States)

    Breidbach, Olaf

    2007-08-01

    Following the concept of internal representations, signal processing in a neuronal system has to be evaluated exclusively based on internal system characteristics. Thus, this approach omits the external observer as a control function for sensory integration. Instead, the configuration of the system and its computational performance are the effects of endogenous factors. Such self-referential operation is due to a strictly local computation in a network and, thereby, computations follow a set of rules that constitute the emergent behaviour of the system. These rules can be shown to correspond to a "logic" that is intrinsic to the system, an idea which provides the basis for neurosemantics.

  6. Novel model of neuronal bioenergetics

    DEFF Research Database (Denmark)

    Bak, Lasse Kristoffer; Obel, Linea Lykke Frimodt; Walls, Anne B

    2012-01-01

    matrix thus activating the tricarboxylic acid cycle dehydrogenases. This will lead to a lower activity of the MASH (malate-aspartate shuttle), which in turn will result in anaerobic glycolysis and lactate production rather than lactate utilization. In the present work, we have investigated the effect...... is positively correlated with intracellular Ca2+ whereas lactate utilization is not. This result lends further support for a significant role of glucose in neuronal bioenergetics and that Ca2+ signalling may control the switch between glucose and lactate utilization during synaptic activity. Based...... a positive correlation between oxidative metabolism of glucose and Ca2+ signalling....

  7. Arc - An endogenous neuronal retrovirus?

    Science.gov (United States)

    Shepherd, Jason D

    2018-05-01

    The neuronal gene Arc is essential for long-lasting information storage in the mammalian brain and has been implicated in various neurological disorders. However, little is known about Arc's evolutionary origins. Recent studies suggest that mammalian Arc originated from a vertebrate lineage of Ty3/gypsy retrotransposons, which are also ancestral to retroviruses. In particular, Arc contains homology to the Gag polyprotein that forms the viral capsid and is essential for viral infectivity. This surprising connection raises the intriguing possibility that Arc may share molecular characteristics of retroviruses. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. High-Degree Neurons Feed Cortical Computations.

    Directory of Open Access Journals (Sweden)

    Nicholas M Timme

    2016-05-01

    Full Text Available Recent work has shown that functional connectivity among cortical neurons is highly varied, with a small percentage of neurons having many more connections than others. Also, recent theoretical developments now make it possible to quantify how neurons modify information from the connections they receive. Therefore, it is now possible to investigate how information modification, or computation, depends on the number of connections a neuron receives (in-degree or sends out (out-degree. To do this, we recorded the simultaneous spiking activity of hundreds of neurons in cortico-hippocampal slice cultures using a high-density 512-electrode array. This preparation and recording method combination produced large numbers of neurons recorded at temporal and spatial resolutions that are not currently available in any in vivo recording system. We utilized transfer entropy (a well-established method for detecting linear and nonlinear interactions in time series and the partial information decomposition (a powerful, recently developed tool for dissecting multivariate information processing into distinct parts to quantify computation between neurons where information flows converged. We found that computations did not occur equally in all neurons throughout the networks. Surprisingly, neurons that computed large amounts of information tended to receive connections from high out-degree neurons. However, the in-degree of a neuron was not related to the amount of information it computed. To gain insight into these findings, we developed a simple feedforward network model. We found that a degree-modified Hebbian wiring rule best reproduced the pattern of computation and degree correlation results seen in the real data. Interestingly, this rule also maximized signal propagation in the presence of network-wide correlations, suggesting a mechanism by which cortex could deal with common random background input. These are the first results to show that the extent to

  9. Mirror neurons: From origin to function

    OpenAIRE

    Cook, R; Bird, G; Catmur, C; Press, C; Heyes, C

    2014-01-01

    This article argues that mirror neurons originate in sensorimotor associative learning and therefore a new approach is needed to investigate their functions. Mirror neurons were discovered about 20 years ago in the monkey brain, and there is now evidence that they are also present in the human brain. The intriguing feature of many mirror neurons is that they fire not only when the animal is performing an action, such as grasping an object using a power grip, but also when the animal passively...

  10. Do enteric neurons make hypocretin? ☆

    OpenAIRE

    Baumann, Christian R.; Clark, Erika L.; Pedersen, Nigel P.; Hecht, Jonathan L.; Scammell, Thomas E.

    2007-01-01

    Hypocretins (orexins) are wake-promoting neuropeptides produced by hypothalamic neurons. These hypocretin-producing cells are lost in people with narcolepsy, possibly due to an autoimmune attack. Prior studies described hypocretin neurons in the enteric nervous system, and these cells could be an additional target of an autoimmune process. We sought to determine whether enteric hypocretin neurons are lost in narcoleptic subjects. Even though we tried several methods (including whole mounts, s...

  11. Synchronous Behavior of Two Coupled Biological Neurons

    International Nuclear Information System (INIS)

    Elson, R.C.; Selverston, A.I.; Elson, R.C.; Selverston, A.I.; Huerta, R.; Rulkov, N.F.; Rabinovich, M.I.; Abarbanel, H.D.; Selverston, A.I.; Huerta, R.; Abarbanel, H.D.

    1998-01-01

    We report experimental studies of synchronization phenomena in a pair of biological neurons that interact through naturally occurring, electrical coupling. When these neurons generate irregular bursts of spikes, the natural coupling synchronizes slow oscillations of membrane potential, but not the fast spikes. By adding artificial electrical coupling we studied transitions between synchrony and asynchrony in both slow oscillations and fast spikes. We discuss the dynamics of bursting and synchronization in living neurons with distributed functional morphology. copyright 1998 The American Physical Society

  12. A New Population of Parvocellular Oxytocin Neurons Controlling Magnocellular Neuron Activity and Inflammatory Pain Processing.

    Science.gov (United States)

    Eliava, Marina; Melchior, Meggane; Knobloch-Bollmann, H Sophie; Wahis, Jérôme; da Silva Gouveia, Miriam; Tang, Yan; Ciobanu, Alexandru Cristian; Triana Del Rio, Rodrigo; Roth, Lena C; Althammer, Ferdinand; Chavant, Virginie; Goumon, Yannick; Gruber, Tim; Petit-Demoulière, Nathalie; Busnelli, Marta; Chini, Bice; Tan, Linette L; Mitre, Mariela; Froemke, Robert C; Chao, Moses V; Giese, Günter; Sprengel, Rolf; Kuner, Rohini; Poisbeau, Pierrick; Seeburg, Peter H; Stoop, Ron; Charlet, Alexandre; Grinevich, Valery

    2016-03-16

    Oxytocin (OT) is a neuropeptide elaborated by the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei. Magnocellular OT neurons of these nuclei innervate numerous forebrain regions and release OT into the blood from the posterior pituitary. The PVN also harbors parvocellular OT cells that project to the brainstem and spinal cord, but their function has not been directly assessed. Here, we identified a subset of approximately 30 parvocellular OT neurons, with collateral projections onto magnocellular OT neurons and neurons of deep layers of the spinal cord. Evoked OT release from these OT neurons suppresses nociception and promotes analgesia in an animal model of inflammatory pain. Our findings identify a new population of OT neurons that modulates nociception in a two tier process: (1) directly by release of OT from axons onto sensory spinal cord neurons and inhibiting their activity and (2) indirectly by stimulating OT release from SON neurons into the periphery. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Molecular Programming of Mesodiencephalic Dopaminergic Neuronal Subsets

    Directory of Open Access Journals (Sweden)

    Marten P. Smidt

    2017-07-01

    Full Text Available Dopamine neurons of the substantia nigra compacta (SNc and ventral tegmental area (VTA are critical components of the neuronal machinery to control emotion and movement in mammals. The slow and gradual death of these neurons as seen in Parkinson's disease has triggered a large investment in research toward unraveling the molecular determinants that are used to generate these neurons and to get an insight in their apparent selective vulnerability. Here, I set out to summarize the current view on the molecular distinctions that exist within this mesodiencephalic dopamine (mdDA system and elaborate on the molecular programming that is responsible for creating such diversity.

  14. Mechanisms of Neuronal Apoptosis In Vivo

    National Research Council Canada - National Science Library

    Martin, Lee J

    2004-01-01

    .... Neuronal cell death in the form of apoptosis or necrosis occurs after exposure to neurotoxins, chemical warfare agents, radiation, viruses, and after seizures, trauma, limb amputation, and hypoxic...

  15. Autosomal dominant adult neuronal ceroid lipofuscinosis

    NARCIS (Netherlands)

    Nijssen, Peter C.G.

    2011-01-01

    this thesis investigates a family with autosomal dominant neuronal ceroid lipofuscinosis, with chapters on clinical neurology, neuropathology, neurogenetics, neurophysiology, auditory and visual aspects.

  16. Shaping Neuronal Network Activity by Presynaptic Mechanisms.

    Directory of Open Access Journals (Sweden)

    Ayal Lavi

    2015-09-01

    Full Text Available Neuronal microcircuits generate oscillatory activity, which has been linked to basic functions such as sleep, learning and sensorimotor gating. Although synaptic release processes are well known for their ability to shape the interaction between neurons in microcircuits, most computational models do not simulate the synaptic transmission process directly and hence cannot explain how changes in synaptic parameters alter neuronal network activity. In this paper, we present a novel neuronal network model that incorporates presynaptic release mechanisms, such as vesicle pool dynamics and calcium-dependent release probability, to model the spontaneous activity of neuronal networks. The model, which is based on modified leaky integrate-and-fire neurons, generates spontaneous network activity patterns, which are similar to experimental data and robust under changes in the model's primary gain parameters such as excitatory postsynaptic potential and connectivity ratio. Furthermore, it reliably recreates experimental findings and provides mechanistic explanations for data obtained from microelectrode array recordings, such as network burst termination and the effects of pharmacological and genetic manipulations. The model demonstrates how elevated asynchronous release, but not spontaneous release, synchronizes neuronal network activity and reveals that asynchronous release enhances utilization of the recycling vesicle pool to induce the network effect. The model further predicts a positive correlation between vesicle priming at the single-neuron level and burst frequency at the network level; this prediction is supported by experimental findings. Thus, the model is utilized to reveal how synaptic release processes at the neuronal level govern activity patterns and synchronization at the network level.

  17. Macroscopic Description for Networks of Spiking Neurons

    Science.gov (United States)

    Montbrió, Ernest; Pazó, Diego; Roxin, Alex

    2015-04-01

    A major goal of neuroscience, statistical physics, and nonlinear dynamics is to understand how brain function arises from the collective dynamics of networks of spiking neurons. This challenge has been chiefly addressed through large-scale numerical simulations. Alternatively, researchers have formulated mean-field theories to gain insight into macroscopic states of large neuronal networks in terms of the collective firing activity of the neurons, or the firing rate. However, these theories have not succeeded in establishing an exact correspondence between the firing rate of the network and the underlying microscopic state of the spiking neurons. This has largely constrained the range of applicability of such macroscopic descriptions, particularly when trying to describe neuronal synchronization. Here, we provide the derivation of a set of exact macroscopic equations for a network of spiking neurons. Our results reveal that the spike generation mechanism of individual neurons introduces an effective coupling between two biophysically relevant macroscopic quantities, the firing rate and the mean membrane potential, which together govern the evolution of the neuronal network. The resulting equations exactly describe all possible macroscopic dynamical states of the network, including states of synchronous spiking activity. Finally, we show that the firing-rate description is related, via a conformal map, to a low-dimensional description in terms of the Kuramoto order parameter, called Ott-Antonsen theory. We anticipate that our results will be an important tool in investigating how large networks of spiking neurons self-organize in time to process and encode information in the brain.

  18. Glutamate mediated astrocytic filtering of neuronal activity.

    Directory of Open Access Journals (Sweden)

    Gilad Wallach

    2014-12-01

    Full Text Available Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity.

  19. Glutamate Mediated Astrocytic Filtering of Neuronal Activity

    Science.gov (United States)

    Herzog, Nitzan; De Pittà, Maurizio; Jacob, Eshel Ben; Berry, Hugues; Hanein, Yael

    2014-01-01

    Neuron-astrocyte communication is an important regulatory mechanism in various brain functions but its complexity and role are yet to be fully understood. In particular, the temporal pattern of astrocyte response to neuronal firing has not been fully characterized. Here, we used neuron-astrocyte cultures on multi-electrode arrays coupled to Ca2+ imaging and explored the range of neuronal stimulation frequencies while keeping constant the amount of stimulation. Our results reveal that astrocytes specifically respond to the frequency of neuronal stimulation by intracellular Ca2+ transients, with a clear onset of astrocytic activation at neuron firing rates around 3-5 Hz. The cell-to-cell heterogeneity of the astrocyte Ca2+ response was however large and increasing with stimulation frequency. Astrocytic activation by neurons was abolished with antagonists of type I metabotropic glutamate receptor, validating the glutamate-dependence of this neuron-to-astrocyte pathway. Using a realistic biophysical model of glutamate-based intracellular calcium signaling in astrocytes, we suggest that the stepwise response is due to the supralinear dynamics of intracellular IP3 and that the heterogeneity of the responses may be due to the heterogeneity of the astrocyte-to-astrocyte couplings via gap junction channels. Therefore our results present astrocyte intracellular Ca2+ activity as a nonlinear integrator of glutamate-dependent neuronal activity. PMID:25521344

  20. Effective stimuli for constructing reliable neuron models.

    Directory of Open Access Journals (Sweden)

    Shaul Druckmann

    2011-08-01

    Full Text Available The rich dynamical nature of neurons poses major conceptual and technical challenges for unraveling their nonlinear membrane properties. Traditionally, various current waveforms have been injected at the soma to probe neuron dynamics, but the rationale for selecting specific stimuli has never been rigorously justified. The present experimental and theoretical study proposes a novel framework, inspired by learning theory, for objectively selecting the stimuli that best unravel the neuron's dynamics. The efficacy of stimuli is assessed in terms of their ability to constrain the parameter space of biophysically detailed conductance-based models that faithfully replicate the neuron's dynamics as attested by their ability to generalize well to the neuron's response to novel experimental stimuli. We used this framework to evaluate a variety of stimuli in different types of cortical neurons, ages and animals. Despite their simplicity, a set of stimuli consisting of step and ramp current pulses outperforms synaptic-like noisy stimuli in revealing the dynamics of these neurons. The general framework that we propose paves a new way for defining, evaluating and standardizing effective electrical probing of neurons and will thus lay the foundation for a much deeper understanding of the electrical nature of these highly sophisticated and non-linear devices and of the neuronal networks that they compose.

  1. Spiking Neurons for Analysis of Patterns

    Science.gov (United States)

    Huntsberger, Terrance

    2008-01-01

    Artificial neural networks comprising spiking neurons of a novel type have been conceived as improved pattern-analysis and pattern-recognition computational systems. These neurons are represented by a mathematical model denoted the state-variable model (SVM), which among other things, exploits a computational parallelism inherent in spiking-neuron geometry. Networks of SVM neurons offer advantages of speed and computational efficiency, relative to traditional artificial neural networks. The SVM also overcomes some of the limitations of prior spiking-neuron models. There are numerous potential pattern-recognition, tracking, and data-reduction (data preprocessing) applications for these SVM neural networks on Earth and in exploration of remote planets. Spiking neurons imitate biological neurons more closely than do the neurons of traditional artificial neural networks. A spiking neuron includes a central cell body (soma) surrounded by a tree-like interconnection network (dendrites). Spiking neurons are so named because they generate trains of output pulses (spikes) in response to inputs received from sensors or from other neurons. They gain their speed advantage over traditional neural networks by using the timing of individual spikes for computation, whereas traditional artificial neurons use averages of activity levels over time. Moreover, spiking neurons use the delays inherent in dendritic processing in order to efficiently encode the information content of incoming signals. Because traditional artificial neurons fail to capture this encoding, they have less processing capability, and so it is necessary to use more gates when implementing traditional artificial neurons in electronic circuitry. Such higher-order functions as dynamic tasking are effected by use of pools (collections) of spiking neurons interconnected by spike-transmitting fibers. The SVM includes adaptive thresholds and submodels of transport of ions (in imitation of such transport in biological

  2. Motor cortex-periaqueductal gray-spinal cord neuronal circuitry may involve in modulation of nociception: a virally mediated transsynaptic tracing study in spinally transected transgenic mouse model.

    Directory of Open Access Journals (Sweden)

    Da-Wei Ye

    Full Text Available Several studies have shown that motor cortex stimulation provided pain relief by motor cortex plasticity and activating descending inhibitory pain control systems. Recent evidence indicated that the melanocortin-4 receptor (MC4R in the periaqueductal gray played an important role in neuropathic pain. This study was designed to assess whether MC4R signaling existed in motor cortex-periaqueductal gray-spinal cord neuronal circuitry modulated the activity of sympathetic pathway by a virally mediated transsynaptic tracing study. Pseudorabies virus (PRV-614 was injected into the left gastrocnemius muscle in adult male MC4R-green fluorescent protein (GFP transgenic mice (n = 15. After a survival time of 4-6 days, the mice (n = 5 were randomly assigned to humanely sacrifice, and spinal cords and brains were removed and sectioned, and processed for PRV-614 visualization. Neurons involved in the efferent control of the left gastrocnemius muscle were identified following visualization of PRV-614 retrograde tracing. The neurochemical phenotype of MC4R-GFP-positive neurons was identified using fluorescence immunocytochemical labeling. PRV-614/MC4R-GFP dual labeled neurons were detected in spinal IML, periaqueductal gray and motor cortex. Our findings support the hypothesis that MC4R signaling in motor cortex-periaqueductal gray-spinal cord neural pathway may participate in the modulation of the melanocortin-sympathetic signaling and contribute to the descending modulation of nociceptive transmission, suggesting that MC4R signaling in motor cortex-periaqueductal gray-spinal cord neural pathway may modulate the activity of sympathetic outflow sensitive to nociceptive signals.

  3. Three-dimensional distribution of tyrosine hydroxylase, vasopressin and oxytocin neurones in the transparent postnatal mouse brain.

    Science.gov (United States)

    Godefroy, D; Dominici, C; Hardin-Pouzet, H; Anouar, Y; Melik-Parsadaniantz, S; Rostène, W; Reaux-Le Goazigo, A

    2017-12-01

    Over the years, advances in immunohistochemistry techniques have been a critical step in detecting and mapping neuromodulatory substances in the central nervous system. The better quality and specificity of primary antibodies, new staining procedures and the spectacular development of imaging technologies have allowed such progress. Very recently, new methods permitting tissue transparency have been successfully used on brain tissues. In the present study, we combined whole-mount immunostaining for tyrosine hydroxylase (TH), oxytocin (OXT) and arginine vasopressin (AVP), with the iDISCO+ clearing method, light-sheet microscopy and semi-automated counting of three-dimensionally-labelled neurones to obtain a (3D) distribution of these neuronal populations in a 5-day postnatal (P5) mouse brain. Segmentation procedure and 3D reconstruction allowed us, with high resolution, to map TH staining of the various catecholaminergic cell groups and their ascending and descending fibre pathways. We show that TH pathways are present in the whole P5 mouse brain, similar to that observed in the adult rat brain. We also provide new information on the postnatal distribution of OXT and AVP immunoreactive cells in the mouse hypothalamus, and show that, compared to AVP neurones, OXT neurones in the supraoptic (SON) and paraventricular (PVN) nuclei are not yet mature in the early postnatal period. 3D semi-automatic quantitative analysis of the PVN reveals that OXT cell bodies are more numerous than AVP neurones, although their immunoreactive soma have a volume half smaller. More AVP nerve fibres compared to OXT were observed in the PVN and the retrochiasmatic area. In conclusion, the results of the present study demonstrate the utility and the potency of imaging large brain tissues with clearing procedures coupled to novel 3D imaging technologies to study, localise and quantify neurotransmitter substances involved in brain and neuroendocrine functions. © 2017 British Society for

  4. Synaptic NMDA Receptor-Dependent Ca2+ Entry Drives Membrane Potential and Ca2+ Oscillations in Spinal Ventral Horn Neurons

    Science.gov (United States)

    Alpert, Michael H.; Alford, Simon

    2013-01-01

    During vertebrate locomotion, spinal neurons act as oscillators when initiated by glutamate release from descending systems. Activation of NMDA receptors initiates Ca2+-mediated intrinsic membrane potential oscillations in central pattern generator (CPG) neurons. NMDA receptor-dependent intrinsic oscillations require Ca2+-dependent K+ (KCa2) channels for burst termination. However, the location of Ca2+ entry mediating KCa2 channel activation, and type of Ca2+ channel – which includes NMDA receptors and voltage-gated Ca2+ channels (VGCCs) – remains elusive. NMDA receptor-dependent Ca2+ entry necessitates presynaptic release of glutamate, implying a location at active synapses within dendrites, whereas VGCC-dependent Ca2+ entry is not similarly constrained. Where Ca2+ enters relative to KCa2 channels is crucial to information processing of synaptic inputs necessary to coordinate locomotion. We demonstrate that Ca2+ permeating NMDA receptors is the dominant source of Ca2+ during NMDA-dependent oscillations in lamprey spinal neurons. This Ca2+ entry is synaptically located, NMDA receptor-dependent, and sufficient to activate KCa2 channels at excitatory interneuron synapses onto other CPG neurons. Selective blockade of VGCCs reduces whole-cell Ca2+ entry but leaves membrane potential and Ca2+ oscillations unaffected. Furthermore, repetitive oscillations are prevented by fast, but not slow, Ca2+ chelation. Taken together, these results demonstrate that KCa2 channels are closely located to NMDA receptor-dependent Ca2+ entry. The close spatial relationship between NMDA receptors and KCa2 channels provides an intrinsic mechanism whereby synaptic excitation both excites and subsequently inhibits ventral horn neurons of the spinal motor system. This places the components necessary for oscillation generation, and hence locomotion, at glutamatergic synapses. PMID:23646190

  5. Discrimination of communication vocalizations by single neurons and groups of neurons in the auditory midbrain.

    Science.gov (United States)

    Schneider, David M; Woolley, Sarah M N

    2010-06-01

    Many social animals including songbirds use communication vocalizations for individual recognition. The perception of vocalizations depends on the encoding of complex sounds by neurons in the ascending auditory system, each of which is tuned to a particular subset of acoustic features. Here, we examined how well the responses of single auditory neurons could be used to discriminate among bird songs and we compared discriminability to spectrotemporal tuning. We then used biologically realistic models of pooled neural responses to test whether the responses of groups of neurons discriminated among songs better than the responses of single neurons and whether discrimination by groups of neurons was related to spectrotemporal tuning and trial-to-trial response variability. The responses of single auditory midbrain neurons could be used to discriminate among vocalizations with a wide range of abilities, ranging from chance to 100%. The ability to discriminate among songs using single neuron responses was not correlated with spectrotemporal tuning. Pooling the responses of pairs of neurons generally led to better discrimination than the average of the two inputs and the most discriminating input. Pooling the responses of three to five single neurons continued to improve neural discrimination. The increase in discriminability was largest for groups of neurons with similar spectrotemporal tuning. Further, we found that groups of neurons with correlated spike trains achieved the largest gains in discriminability. We simulated neurons with varying levels of temporal precision and measured the discriminability of responses from single simulated neurons and groups of simulated neurons. Simulated neurons with biologically observed levels of temporal precision benefited more from pooling correlated inputs than did neurons with highly precise or imprecise spike trains. These findings suggest that pooling correlated neural responses with the levels of precision observed in the

  6. Stages of neuronal network formation

    Science.gov (United States)

    Woiterski, Lydia; Claudepierre, Thomas; Luxenhofer, Robert; Jordan, Rainer; Käs, Josef A.

    2013-02-01

    Graph theoretical approaches have become a powerful tool for investigating the architecture and dynamics of complex networks. The topology of network graphs revealed small-world properties for very different real systems among these neuronal networks. In this study, we observed the early development of mouse retinal ganglion cell (RGC) networks in vitro using time-lapse video microscopy. By means of a time-resolved graph theoretical analysis of the connectivity, shortest path length and the edge length, we were able to discover the different stages during the network formation. Starting from single cells, at the first stage neurons connected to each other ending up in a network with maximum complexity. In the further course, we observed a simplification of the network which manifested in a change of relevant network parameters such as the minimization of the path length. Moreover, we found that RGC networks self-organized as small-world networks at both stages; however, the optimization occurred only in the second stage.

  7. Differentiating lower motor neuron syndromes.

    Science.gov (United States)

    Garg, Nidhi; Park, Susanna B; Vucic, Steve; Yiannikas, Con; Spies, Judy; Howells, James; Huynh, William; Matamala, José M; Krishnan, Arun V; Pollard, John D; Cornblath, David R; Reilly, Mary M; Kiernan, Matthew C

    2017-06-01

    Lower motor neuron (LMN) syndromes typically present with muscle wasting and weakness and may arise from pathology affecting the distal motor nerve up to the level of the anterior horn cell. A variety of hereditary causes are recognised, including spinal muscular atrophy, distal hereditary motor neuropathy and LMN variants of familial motor neuron disease. Recent genetic advances have resulted in the identification of a variety of disease-causing mutations. Immune-mediated disorders, including multifocal motor neuropathy and variants of chronic inflammatory demyelinating polyneuropathy, account for a proportion of LMN presentations and are important to recognise, as effective treatments are available. The present review will outline the spectrum of LMN syndromes that may develop in adulthood and provide a framework for the clinician assessing a patient presenting with predominantly LMN features. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  8. Ruptura traumática de la aorta descendente torácica Traumatic ruptura of the descending thoracic aorta

    Directory of Open Access Journals (Sweden)

    Gabriel González Sosa

    2013-03-01

    in the posterior region of the right hemithorax, below the lower rim of the scapula. It was a penetrating wound in the thoracic cavity caused by a short sharpened object; a piece of this object was trapped into the cavity and caused a 3 cm long injury, at the level of the thoracic descending aorta. The patient was operated on in an emergency situation and the vascular injury was successfully sutured, a procedure that barely has positive results due to the high mortality rate of this type of injuries. Most of the affected people die before arriving to the specialized health center.

  9. Essential roles of mitochondrial depolarization in neuron loss through microglial activation and attraction toward neurons.

    Science.gov (United States)

    Nam, Min-Kyung; Shin, Hyun-Ah; Han, Ji-Hye; Park, Dae-Wook; Rhim, Hyangshuk

    2013-04-10

    As life spans increased, neurodegenerative disorders that affect aging populations have also increased. Progressive neuronal loss in specific brain regions is the most common cause of neurodegenerative disease; however, key determinants mediating neuron loss are not fully understood. Using a model of mitochondrial membrane potential (ΔΨm) loss, we found only 25% cell loss in SH-SY5Y (SH) neuronal mono-cultures, but interestingly, 85% neuronal loss occurred when neurons were co-cultured with BV2 microglia. SH neurons overexpressing uncoupling protein 2 exhibited an increase in neuron-microglia interactions, which represent an early step in microglial phagocytosis of neurons. This result indicates that ΔΨm loss in SH neurons is an important contributor to recruitment of BV2 microglia. Notably, we show that ΔΨm loss in BV2 microglia plays a crucial role in microglial activation and phagocytosis of damaged SH neurons. Thus, our study demonstrates that ΔΨm loss in both neurons and microglia is a critical determinant of neuron loss. These findings also offer new insights into neuroimmunological and bioenergetical aspects of neurodegenerative disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses.

    Science.gov (United States)

    Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

    2015-12-01

    Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it.

  11. Cerebellar Nuclear Neurons Use Time and Rate Coding to Transmit Purkinje Neuron Pauses

    Science.gov (United States)

    Sudhakar, Shyam Kumar; Torben-Nielsen, Benjamin; De Schutter, Erik

    2015-01-01

    Neurons of the cerebellar nuclei convey the final output of the cerebellum to their targets in various parts of the brain. Within the cerebellum their direct upstream connections originate from inhibitory Purkinje neurons. Purkinje neurons have a complex firing pattern of regular spikes interrupted by intermittent pauses of variable length. How can the cerebellar nucleus process this complex input pattern? In this modeling study, we investigate different forms of Purkinje neuron simple spike pause synchrony and its influence on candidate coding strategies in the cerebellar nuclei. That is, we investigate how different alignments of synchronous pauses in synthetic Purkinje neuron spike trains affect either time-locking or rate-changes in the downstream nuclei. We find that Purkinje neuron synchrony is mainly represented by changes in the firing rate of cerebellar nuclei neurons. Pause beginning synchronization produced a unique effect on nuclei neuron firing, while the effect of pause ending and pause overlapping synchronization could not be distinguished from each other. Pause beginning synchronization produced better time-locking of nuclear neurons for short length pauses. We also characterize the effect of pause length and spike jitter on the nuclear neuron firing. Additionally, we find that the rate of rebound responses in nuclear neurons after a synchronous pause is controlled by the firing rate of Purkinje neurons preceding it. PMID:26630202

  12. Inhibitory neurons modulate spontaneous signaling in cultured cortical neurons: density-dependent regulation of excitatory neuronal signaling

    International Nuclear Information System (INIS)

    Serra, Michael; Guaraldi, Mary; Shea, Thomas B

    2010-01-01

    Cortical neuronal activity depends on a balance between excitatory and inhibitory influences. Culturing of neurons on multi-electrode arrays (MEAs) has provided insight into the development and maintenance of neuronal networks. Herein, we seeded MEAs with murine embryonic cortical/hippocampal neurons at different densities ( 1000 cells mm −2 ) and monitored resultant spontaneous signaling. Sparsely seeded cultures displayed a large number of bipolar, rapid, high-amplitude individual signals with no apparent temporal regularity. By contrast, densely seeded cultures instead displayed clusters of signals at regular intervals. These patterns were observed even within thinner and thicker areas of the same culture. GABAergic neurons (25% of total neurons in our cultures) mediated the differential signal patterns observed above, since addition of the inhibitory antagonist bicuculline to dense cultures and hippocampal slice cultures induced the signal pattern characteristic of sparse cultures. Sparsely seeded cultures likely lacked sufficient inhibitory neurons to modulate excitatory activity. Differential seeding of MEAs can provide a unique model for analyses of pertubation in the interaction between excitatory and inhibitory function during aging and neuropathological conditions where dysregulation of GABAergic neurons is a significant component

  13. Failure of action potential propagation in sensory neurons: mechanisms and loss of afferent filtering in C-type units after painful nerve injury.

    Science.gov (United States)

    Gemes, Geza; Koopmeiners, Andrew; Rigaud, Marcel; Lirk, Philipp; Sapunar, Damir; Bangaru, Madhavi Latha; Vilceanu, Daniel; Garrison, Sheldon R; Ljubkovic, Marko; Mueller, Samantha J; Stucky, Cheryl L; Hogan, Quinn H

    2013-02-15

    The T-junction of sensory neurons in the dorsal root ganglion (DRG) is a potential impediment to action potential (AP) propagation towards the CNS. Using intracellular recordings from rat DRG neuronal somata during stimulation of the dorsal root, we determined that the maximal rate at which all of 20 APs in a train could successfully transit the T-junction (following frequency) was lowest in C-type units, followed by A-type units with inflected descending limbs of the AP, and highest in A-type units without inflections. In C-type units, following frequency was slower than the rate at which AP trains could be produced in either dorsal root axonal segments or in the soma alone, indicating that the T-junction is a site that acts as a low-pass filter for AP propagation. Following frequency was slower for a train of 20 APs than for two, indicating that a cumulative process leads to propagation failure. Propagation failure was accompanied by diminished somatic membrane input resistance, and was enhanced when Ca(2+)-sensitive K(+) currents were augmented or when Ca(2+)-sensitive Cl(-) currents were blocked. After peripheral nerve injury, following frequencies were increased in axotomized C-type neurons and decreased in axotomized non-inflected A-type neurons. These findings reveal that the T-junction in sensory neurons is a regulator of afferent impulse traffic. Diminished filtering of AP trains at the T-junction of C-type neurons with axotomized peripheral processes could enhance the transmission of activity that is ectopically triggered in a neuroma or the neuronal soma, possibly contributing to pain generation.

  14. Neuron Morphology Influences Axon Initial Segment Plasticity.

    Science.gov (United States)

    Gulledge, Allan T; Bravo, Jaime J

    2016-01-01

    In most vertebrate neurons, action potentials are initiated in the axon initial segment (AIS), a specialized region of the axon containing a high density of voltage-gated sodium and potassium channels. It has recently been proposed that neurons use plasticity of AIS length and/or location to regulate their intrinsic excitability. Here we quantify the impact of neuron morphology on AIS plasticity using computational models of simplified and realistic somatodendritic morphologies. In small neurons (e.g., dentate granule neurons), excitability was highest when the AIS was of intermediate length and located adjacent to the soma. Conversely, neurons having larger dendritic trees (e.g., pyramidal neurons) were most excitable when the AIS was longer and/or located away from the soma. For any given somatodendritic morphology, increasing dendritic membrane capacitance and/or conductance favored a longer and more distally located AIS. Overall, changes to AIS length, with corresponding changes in total sodium conductance, were far more effective in regulating neuron excitability than were changes in AIS location, while dendritic capacitance had a larger impact on AIS performance than did dendritic conductance. The somatodendritic influence on AIS performance reflects modest soma-to-AIS voltage attenuation combined with neuron size-dependent changes in AIS input resistance, effective membrane time constant, and isolation from somatodendritic capacitance. We conclude that the impact of AIS plasticity on neuron excitability will depend largely on somatodendritic morphology, and that, in some neurons, a shorter or more distally located AIS may promote, rather than limit, action potential generation.

  15. Interactive Exploration for Continuously Expanding Neuron Databases.

    Science.gov (United States)

    Li, Zhongyu; Metaxas, Dimitris N; Lu, Aidong; Zhang, Shaoting

    2017-02-15

    This paper proposes a novel framework to help biologists explore and analyze neurons based on retrieval of data from neuron morphological databases. In recent years, the continuously expanding neuron databases provide a rich source of information to associate neuronal morphologies with their functional properties. We design a coarse-to-fine framework for efficient and effective data retrieval from large-scale neuron databases. In the coarse-level, for efficiency in large-scale, we employ a binary coding method to compress morphological features into binary codes of tens of bits. Short binary codes allow for real-time similarity searching in Hamming space. Because the neuron databases are continuously expanding, it is inefficient to re-train the binary coding model from scratch when adding new neurons. To solve this problem, we extend binary coding with online updating schemes, which only considers the newly added neurons and update the model on-the-fly, without accessing the whole neuron databases. In the fine-grained level, we introduce domain experts/users in the framework, which can give relevance feedback for the binary coding based retrieval results. This interactive strategy can improve the retrieval performance through re-ranking the above coarse results, where we design a new similarity measure and take the feedback into account. Our framework is validated on more than 17,000 neuron cells, showing promising retrieval accuracy and efficiency. Moreover, we demonstrate its use case in assisting biologists to identify and explore unknown neurons. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

    Science.gov (United States)

    Food sources of arachidonic acid (PFA 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

  17. Food sources of total omega 6 fatty acids (18:2 + 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

    Science.gov (United States)

    Food sources of total omega 6 fatty acids (18:2 + 20:4), listed in descending order by percentages of their contribution to intake, based on data from the National Health and Nutrition Examination Survey 2005-2006

  18. Interdisciplinary approaches of transcranial magnetic stimulation applied to a respiratory neuronal circuitry model.

    Directory of Open Access Journals (Sweden)

    Stéphane Vinit

    Full Text Available Respiratory related diseases associated with the neuronal control of breathing represent life-threatening issues and to date, no effective therapeutics are available to enhance the impaired function. The aim of this study was to determine whether a preclinical respiratory model could be used for further studies to develop a non-invasive therapeutic tool applied to rat diaphragmatic neuronal circuitry. Transcranial magnetic stimulation (TMS was performed on adult male Sprague-Dawley rats using a human figure-of-eight coil. The largest diaphragmatic motor evoked potentials (MEPdia were recorded when the center of the coil was positioned 6 mm caudal from Bregma, involving a stimulation of respiratory supraspinal pathways. Magnetic shielding of the coil with mu metal reduced magnetic field intensities and improved focality with increased motor threshold and lower amplitude recruitment curve. Moreover, transynaptic neuroanatomical tracing with pseudorabies virus (applied to the diaphragm suggest that connections exist between the motor cortex, the periaqueductal grey cell regions, several brainstem neurons and spinal phrenic motoneurons (distributed in the C3-4 spinal cord. These results reveal the anatomical substrate through which supraspinal stimulation can convey descending action potential volleys to the spinal motoneurons (directly or indirectly. We conclude that MEPdia following a single pulse of TMS can be successfully recorded in the rat and may be used in the assessment of respiratory supraspinal plasticity. Supraspinal non-invasive stimulations aimed to neuromodulate respiratory circuitry will enable new avenues of research into neuroplasticity and the development of therapies for respiratory dysfunction associated with neural injury and disease (e.g. spinal cord injury, amyotrophic lateral sclerosis.

  19. Heavy metals in locus ceruleus and motor neurons in motor neuron disease.

    Science.gov (United States)

    Pamphlett, Roger; Kum Jew, Stephen

    2013-12-12

    The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons.

  20. Heavy metals in locus ceruleus and motor neurons in motor neuron disease

    Science.gov (United States)

    2013-01-01

    Background The causes of sporadic amyotrophic lateral sclerosis (SALS) and other types of motor neuron disease (MND) remain largely unknown. Heavy metals have long been implicated in MND, and it has recently been shown that inorganic mercury selectively enters human locus ceruleus (LC) and motor neurons. We therefore used silver nitrate autometallography (AMG) to look for AMG-stainable heavy metals (inorganic mercury and bismuth) in LC and motor neurons of 24 patients with MND (18 with SALS and 6 with familial MND) and in the LC of 24 controls. Results Heavy metals in neurons were found in significantly more MND patients than in controls when comparing: (1) the presence of any versus no heavy metal-containing LC neurons (MND 88%, controls 42%), (2) the median percentage of heavy metal-containing LC neurons (MND 9.5%, control 0.0%), and (3) numbers of individuals with heavy metal-containing LC neurons in the upper half of the percentage range (MND 75%, controls 25%). In MND patients, 67% of remaining spinal motor neurons contained heavy metals; smaller percentages were found in hypoglossal, nucleus ambiguus and oculomotor neurons, but none in cortical motor neurons. The majority of MND patients had heavy metals in both LC and spinal motor neurons. No glia or other neurons, including neuromelanin-containing neurons of the substantia nigra, contained stainable heavy metals. Conclusions Uptake of heavy metals by LC and lower motor neurons appears to be fairly common in humans, though heavy metal staining in the LC, most likely due to inorganic mercury, was seen significantly more often in MND patients than in controls. The LC innervates many cell types that are affected in MND, and it is possible that MND is triggered by toxicant-induced interactions between LC and motor neurons. PMID:24330485

  1. Intratelencephalic corticostriatal neurons equally excite striatonigral and striatopallidal neurons and their discharge activity is selectively reduced in experimental parkinsonism

    OpenAIRE

    Ballion, B. (B.); Mallet, N. (Nicolas); Bezard, E. (E.); Lanciego, J.L. (José Luis); Gonon, F. (Francois)

    2008-01-01

    Striatonigral and striatopallidal neurons form distinct populations of striatal projection neurons. Their discharge activity is imbalanced after dopaminergic degeneration in Parkinson's disease. Striatal projection neurons receive massive cortical excitatory inputs from bilateral intratelencephalic (IT) neurons projecting to both the ipsilateral and contralateral striatum and from collateral axons of ipsilateral neurons that send their main axon through the pyramidal tract (PT). Previous anat...

  2. Phenolic antioxidants attenuate hippocampal neuronal cell damage ...

    Indian Academy of Sciences (India)

    In this regard, certain dietary compounds are begining to receive increased attention, in particular those involving phytochemicals found in medicinal plants in alleviating neuronal injury. In the present study, we examined whether medicinal plant extracts protect neurons against excitotoxic lesions induced by kainic acid (KA) ...

  3. Do mirror neurons subserve action understanding?

    Science.gov (United States)

    Hickok, Gregory

    2013-04-12

    Mirror neurons were once widely believed to support action understanding via motor simulation of the observed actions. Recent evidence regarding the functional properties of mirror neurons in monkeys as well as much neuropsychological evidence in humans has shown that this is not the case. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Mirror neurons: functions, mechanisms and models.

    Science.gov (United States)

    Oztop, Erhan; Kawato, Mitsuo; Arbib, Michael A

    2013-04-12

    Mirror neurons for manipulation fire both when the animal manipulates an object in a specific way and when it sees another animal (or the experimenter) perform an action that is more or less similar. Such neurons were originally found in macaque monkeys, in the ventral premotor cortex, area F5 and later also in the inferior parietal lobule. Recent neuroimaging data indicate that the adult human brain is endowed with a "mirror neuron system," putatively containing mirror neurons and other neurons, for matching the observation and execution of actions. Mirror neurons may serve action recognition in monkeys as well as humans, whereas their putative role in imitation and language may be realized in human but not in monkey. This article shows the important role of computational models in providing sufficient and causal explanations for the observed phenomena involving mirror systems and the learning processes which form them, and underlines the need for additional circuitry to lift up the monkey mirror neuron circuit to sustain the posited cognitive functions attributed to the human mirror neuron system. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  5. Adaptive Neurons For Artificial Neural Networks

    Science.gov (United States)

    Tawel, Raoul

    1990-01-01

    Training time decreases dramatically. In improved mathematical model of neural-network processor, temperature of neurons (in addition to connection strengths, also called weights, of synapses) varied during supervised-learning phase of operation according to mathematical formalism and not heuristic rule. Evidence that biological neural networks also process information at neuronal level.

  6. Do Mirror Neurons Subserve Action Understanding?

    OpenAIRE

    Hickok, Gregory

    2012-01-01

    Mirror neurons were once widely believed to support action understanding via motor simulation of the observed actions. Recent evidence regarding the functional properties of mirror neurons in monkeys as well as much neuropsychological evidence in humans has shown that this is not the case

  7. The Mirror Neuron System and Action Recognition

    Science.gov (United States)

    Buccino, Giovanni; Binkofski, Ferdinand; Riggio, Lucia

    2004-01-01

    Mirror neurons, first described in the rostral part of monkey ventral premotor cortex (area F5), discharge both when the animal performs a goal-directed hand action and when it observes another individual performing the same or a similar action. More recently, in the same area mirror neurons responding to the observation of mouth actions have been…

  8. Where do mirror neurons come from?

    Science.gov (United States)

    Heyes, Cecilia

    2010-03-01

    Debates about the evolution of the 'mirror neuron system' imply that it is an adaptation for action understanding. Alternatively, mirror neurons may be a byproduct of associative learning. Here I argue that the adaptation and associative hypotheses both offer plausible accounts of the origin of mirror neurons, but the associative hypothesis has three advantages. First, it provides a straightforward, testable explanation for the differences between monkeys and humans that have led some researchers to question the existence of a mirror neuron system. Second, it is consistent with emerging evidence that mirror neurons contribute to a range of social cognitive functions, but do not play a dominant, specialised role in action understanding. Finally, the associative hypothesis is supported by recent data showing that, even in adulthood, the mirror neuron system can be transformed by sensorimotor learning. The associative account implies that mirror neurons come from sensorimotor experience, and that much of this experience is obtained through interaction with others. Therefore, if the associative account is correct, the mirror neuron system is a product, as well as a process, of social interaction. (c) 2009 Elsevier Ltd. All rights reserved.

  9. Motors and Adaptors : Transport Regulation within Neurons

    NARCIS (Netherlands)

    van Spronsen, C.S.A.M.|info:eu-repo/dai/nl/337616655

    2012-01-01

    Human thoughts and behavior are the outcome of communication between neurons in our brains. There is an entire world inside each of these neurons where transactions are established and meeting points are set. By using molecular motors to transport proteins and organelles along cytoskeletal tracks,

  10. The Descendants of Time and the Lodgers of Space: The Life Stories of Teacher Trainees who Immigrated to Israel During the 1990s

    Directory of Open Access Journals (Sweden)

    Anat Kainan

    2005-09-01

    Full Text Available This paper attempts to characterize teacher trainees who immigrated to Israel during the 1990s. The life stories of six students who emi­grated from the Ukraine, Russia, the Georgian Re­pub­lic, Argentina, Chile, and Ethiopia are ana­lyzed. The central finding suggests that their stories are devoid of the human, geographic, and cultural aspects of Israeli society. This finding is surprising because it differs from other studies. We used the Foucauldian concepts of the descendants of time and the lodgers of space for understanding the phenomenon. URN: urn:nbn:de:0114-fqs0503103

  11. Giant Coronary Arterial Aneurysm of the Proximal Left Anterior Descending Artery as the Cause of Wide Splitting of the Second Heart Sound.

    Science.gov (United States)

    Nagasawa, Akira; Mori, Shumpei; Akita, Tomomi; Yamada, Haruhi; Oki, Tsumugi; Nishii, Tatsuya; Yamashita, Tomoya; Okita, Yutaka; Hirata, Ken-Ichi

    2017-12-21

    Even in modern clinical cardiology, basic auscultation skill is not obsolete and is still important because it can always provide a clue to an underlying pathophysiology. We demonstrate an unusual mechanism of pathological wide splitting of the second heart sound due to external compression of the pulmonary trunk in a patient with a giant coronary arterial aneurysm of the proximal left anterior descending artery. Echocardiography, when combined with a three-dimensional anatomical analysis with cardiac computed tomography, was useful for elucidating the mechanism of the abnormal heart sounds.

  12. Frozen elephant trunk reconstruction for right-sided aortic arch with aberrant left subclavian artery and aneurysm of the descending aorta: a case report.

    Science.gov (United States)

    Kokotsakis, John; Jarral, Omar A; Harling, Leanne; Tsipas, Panteleimon; Athanasiou, Thanos

    2016-05-05

    A 59-year old man being investigated for back pain was found to have aneurysmal dilatation of a right-sided aortic arch and descending thoracic aorta together with an aberrant left subclavian artery. He underwent repair of this utilising the frozen elephant trunk technique, which dealt with all three pathologies in one-stage. He made an unremarkable recovery and was discharged home on the 8th post-operative day. This case report further demonstrates the flexibility and safety of the frozen elephant trunk in dealing with complex aortic pathology as a single-stage procedure.

  13. Use of cross-border healthcare services among ethnic Danes, Turkish immigrants and Turkish descendants in Denmark: a combined survey and registry study

    Directory of Open Access Journals (Sweden)

    Nielsen Signe

    2012-11-01

    Full Text Available Abstract Background Healthcare obtained abroad may conflict with care received in the country of residence. A special concern for immigrants has been raised as they may have stronger links to healthcare services abroad. Our objective was to investigate use of healthcare in a foreign country in Turkish immigrants, their descendants, and ethnic Danes. Methods The study was based on a nationwide survey in 2007 with 372 Turkish immigrants, 496 descendants, and 1,131 ethnic Danes aged 18–66. Data were linked to registry data on socioeconomic factors. Using logistic regression models, use of doctor, specialist doctor, hospital, dentist in a foreign country as well as medicine from abroad were estimated. Analyses were adjusted for socioeconomic factors and health symptoms. Results Overall, 26.6% among Turkish immigrants made use of cross-border healthcare, followed by 19.4% among their descendants to 6.7% among ethnic Danes. Using logistic regression models with ethnic Danes as the reference group, Turkish immigrants were seen to have made increased use of general practitioners, specialist doctors, hospitals, and dentists in a foreign country (odds ratio (OR, 5.20-6.74, while Turkish descendants had made increased use of specialist doctors (OR, 4.97 and borderline statistically significant increased use of hospital (OR, 2.48 and dentist (OR, 2.17 but not general practitioners. For medicine, we found no differences among the men, but women with an immigrant background made considerably greater use, compared with ethnic Danish women. Socioeconomic position and health symptoms had a fairly explanatory effect on the use in the different groups. Conclusions Use of cross-border healthcare may have consequences for the continuity of care, including conflicts in the medical treatment, for the patient. Nonetheless, it may be aligned with the patient’s preferences and thereby beneficial for the patient. We need more information about reasons for obtaining

  14. Neuronal involvement in cisplatin neuropathy

    DEFF Research Database (Denmark)

    Krarup-Hansen, A; Helweg-Larsen, Susanne Elisabeth; Schmalbruch, H

    2007-01-01

    Although it is well known that cisplatin causes a sensory neuropathy, the primary site of involvement is not established. The clinical symptoms localized in a stocking-glove distribution may be explained by a length dependent neuronopathy or by a distal axonopathy. To study whether the whole neuron...... higher than 300 mg/m2 the patients lost distal tendon and H-reflexes and displayed reduced vibration sense in the feet and the fingers. The amplitudes of sensory nerve action potentials (SNAP) from the fingers innervated by the median nerve and the dorsolateral side of the foot innervated by the sural...... of the foot evoked by a tactile probe showed similar changes to those observed in SNAPs evoked by electrical stimulation. At these doses, somatosensory evoked potentials (SEPs) from the tibial nerve had increased latencies of peripheral, spinal and central responses suggesting loss of central processes...

  15. Nicotinic activation of laterodorsal tegmental neurons

    DEFF Research Database (Denmark)

    Ishibashi, Masaru; Leonard, Christopher S; Kohlmeier, Kristi A

    2009-01-01

    Identifying the neurological mechanisms underlying nicotine reinforcement is a healthcare imperative, if society is to effectively combat tobacco addiction. The majority of studies of the neurobiology of addiction have focused on dopamine (DA)-containing neurons of the ventral tegmental area (VTA......). However, recent data suggest that neurons of the laterodorsal tegmental (LDT) nucleus, which sends cholinergic, GABAergic, and glutamatergic-containing projections to DA-containing neurons of the VTA, are critical to gating normal functioning of this nucleus. The actions of nicotine on LDT neurons...... are unknown. We addressed this issue by examining the effects of nicotine on identified cholinergic and non-cholinergic LDT neurons using whole-cell patch clamp and Ca(2+)-imaging methods in brain slices from mice (P12-P45). Nicotine applied by puffer pipette or bath superfusion elicited membrane...

  16. Mirror neurons through the lens of epigenetics.

    Science.gov (United States)

    Ferrari, Pier F; Tramacere, Antonella; Simpson, Elizabeth A; Iriki, Atsushi

    2013-09-01

    The consensus view in mirror neuron research is that mirror neurons comprise a uniform, stable execution-observation matching system. In this opinion article, we argue that, in light of recent evidence, this is at best an incomplete and oversimplified view of mirror neurons, where activity is actually variable and more plastic than previously theorized. We propose an epigenetic account for understanding developmental changes in sensorimotor systems, including variations in mirror neuron activity. Although associative and genetic accounts fail to consider the complexity of genetic and nongenetic interactions, we propose a new evolutionary developmental biology (evo-devo) perspective, which predicts that environmental differences early in development should produce variations in mirror neuron response patterns, tuning them to the social environment. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Mirror neurons: their implications for group psychotherapy.

    Science.gov (United States)

    Schermer, Victor L

    2010-10-01

    Recently discovered mirror neurons in the motor cortex of the brain register the actions and intentions of both the organism and others in the environment. As such, they may play a significant role in social behavior and groups. This paper considers the potential implications of mirror neurons and related neural networks for group therapists, proposing that mirror neurons and mirror systems provide "hard-wired" support for the group therapist's belief in the centrality of relationships in the treatment process and exploring their value in accounting for group-as-a-whole phenomena. Mirror neurons further confirm the holistic, social nature of perception, action, and intention as distinct from a stimulus-response behaviorism. The implications of mirror neurons and mirroring processes for the group therapist role, interventions, and training are also discussed.

  18. Reflections on mirror neurons and speech perception

    Science.gov (United States)

    Lotto, Andrew J.; Hickok, Gregory S.; Holt, Lori L.

    2010-01-01

    The discovery of mirror neurons, a class of neurons that respond when a monkey performs an action and also when the monkey observes others producing the same action, has promoted a renaissance for the Motor Theory (MT) of speech perception. This is because mirror neurons seem to accomplish the same kind of one to one mapping between perception and action that MT theorizes to be the basis of human speech communication. However, this seeming correspondence is superficial, and there are theoretical and empirical reasons to temper enthusiasm about the explanatory role mirror neurons might have for speech perception. In fact, rather than providing support for MT, mirror neurons are actually inconsistent with the central tenets of MT. PMID:19223222

  19. Power laws from linear neuronal cable theory

    DEFF Research Database (Denmark)

    Pettersen, Klas H; Lindén, Henrik Anders; Tetzlaff, Tom

    2014-01-01

    suggested to be at the root of this phenomenon, we here demonstrate a possible origin of such power laws in the biophysical properties of single neurons described by the standard cable equation. Taking advantage of the analytical tractability of the so called ball and stick neuron model, we derive general...... expressions for the PSD transfer functions for a set of measures of neuronal activity: the soma membrane current, the current-dipole moment (corresponding to the single-neuron EEG contribution), and the soma membrane potential. These PSD transfer functions relate the PSDs of the respective measurements...... to the PSDs of the noisy input currents. With homogeneously distributed input currents across the neuronal membrane we find that all PSD transfer functions express asymptotic high-frequency [Formula: see text] power laws with power-law exponents analytically identified as [Formula: see text] for the soma...

  20. Attractor dynamics in local neuronal networks

    Directory of Open Access Journals (Sweden)

    Jean-Philippe eThivierge

    2014-03-01

    Full Text Available Patterns of synaptic connectivity in various regions of the brain are characterized by the presence of synaptic motifs, defined as unidirectional and bidirectional synaptic contacts that follow a particular configuration and link together small groups of neurons. Recent computational work proposes that a relay network (two populations communicating via a third, relay population of neurons can generate precise patterns of neural synchronization. Here, we employ two distinct models of neuronal dynamics and show that simulated neural circuits designed in this way are caught in a global attractor of activity that prevents neurons from modulating their response on the basis of incoming stimuli. To circumvent the emergence of a fixed global attractor, we propose a mechanism of selective gain inhibition that promotes flexible responses to external stimuli. We suggest that local neuronal circuits may employ this mechanism to generate precise patterns of neural synchronization whose transient nature delimits the occurrence of a brief stimulus.