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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
151

Estudo comparativo entre dois métodos de tratamento da lesão do ligamento cruzado posterior por avulsão óssea na tíbia : amarrilho artroscópico e fixação com parafuso por via posterior aberta / Comparative study between two methods of treatment of tibial posterior cruciate ligament bony avulsion: arthroscopic suture and screw fixation using open posterior approach.

Sandra Umeda Sasaki 15 December 2003 (has links)
Atualmente, os bons resultados na lesão do ligamento cruzado posterior por avulsão óssea na tíbia associam-se ao tratamento cirúrgico e precoce. A técnica convencional é a fixação com parafuso pela via de acesso posterior do joelho, com abordagem direta das estruturas vasculares e nervosas da região. Neste estudo experimental em 20 joelhos de cadáveres, buscamos apresentar uma alternativa com amarrilho por via artroscópica, comparando-o com a técnica convencional, através da inspeção direta e de testes biomecânicos. Houve falha na fixação de apenas um exemplar de cada método e medidas de deslocamento tibial posterior (p=0,23) e rigidez média (p=0,28) sem diferenças significativas entre as duas técnicas. Concluímos ser o amarrilho artroscópico viável e uma alternativa no tratamento desta lesão. / Nowadays, good results on the management of posterior cruciate ligament bony avulsion of the tibia are associated with early surgical repair. The usual method of treatment is the open posterior approach with screw fixation, wich requires popliteal neurovascular bundle direct manipulation. This study presents a new arthroscopic suture and compares it with the conventional technique, using biomechanical tests and direct inspection in cadaveric specimens (20 knees). On both methods there was a fixation fail in one knee. The analisys of tibial posterior displacement (p=0,23) and stiffness (p=0,20) were similar for the two methods. The Arthroscopic suture presented is an effective reattachment method for this fracture pattern.
152

The sandwich theory:a bioactivity based explanation for posterior capsule opacification after cataract surgery with intraocular lens implantation

Linnola, R. (Reijo) 04 May 2001 (has links)
Abstract This study was undertaken to identify mechanisms of adhesion of intraocular lenses (IOLs) to the capsular bag after cataract surgery and IOL implantation. It was also done to challenge the sandwich theory presented for posterior capsular opacification (PCO): If the IOL is made of a bioactive material it would allow a single lens epithelial cell layer to bond both to the IOL and the posterior capsule at the same time. This would produce a sandwich pattern including the IOL, the cell monolayer and the posterior capsule. The sealed sandwich structure would prevent further epithelial ingrowth. The degree of bioactivity of the IOL could explain the basic difference in the incidence of PCO and capsulotomy rates with different IOL materials. The sandwich theory was put forward on the basis of a search for a keratoprosthesis material, which would allow maximal adhesion of the prosthesis to corneal tissue. Titanium and glass-ceramic coated titanium were found to develop better adhesion than poly (methyl methacrylate) (PMMA). The adhesion of PMMA to the corneal stromal tissue was loose, and down growth of corneal epithelial cells was seen around the prosthesis. The differences between various IOL materials were first tested with rabbit corneal tissue cultures. There was better adhesion of corneal tissue to soft, hydrophobic acrylate than to PMMA, heparin surface modified (HSM)-PMMA, silicone or hydrogel IOLs. To assess differences in protein adhesion to IOL surfaces, different IOLs were incubated for 24 hours with radioactive iodine labeled fibronectin. Soft hydrophobic acrylate (AcrySof®) showed the highest binding of fibronectin, and the differences relative to all the other materials were significant (p < 0.01-0.001), except to PMMA (p = 0.31). The sandwich theory and the results with rabbit corneal tissue cultures and the protein adhesion study in vitro were evaluated against the results found in pseudophakic autopsy eyes. Altogether, 70 autopsy eyes were analyzed. From 38 autopsy eyes containing PMMA, silicone, soft hydrophobic acrylate or hydrogel IOLs histological sections were prepared from the capsular bag and immunohistochemical analyses were performed for fibronectin, vitronectin, laminin and collagen type IV. A total of 152 specimens were analyzed. From 32 autopsy eyes containing IOLs made of PMMA, silicone, acrylate or hydrogel, IOLs were explanted from the capsular bag and immunohistochemical analysis was done on both sides of the IOLs for fibronectin, vitronectin, laminin or collagen type IV. Soft hydrophobic acrylate IOLs had significantly more adhesion of fibronectin to their surfaces than PMMA or silicone IOLs. Also, more vitronectin was attached to acrylate IOLs than to the other IOL materials. Silicone IOLs had more collagen type IV adhesion in comparison to the other IOL materials studied. In histologic sections a sandwich-like structure (anterior or posterior capsule-fibronectin-one cell layer-fibronectin-IOL surface) was seen significantly more often in eyes with acrylate IOLs than in PMMA, silicone or hydrogel IOL eyes. These studies support the sandwich theory for posterior capsule opacification after cataract surgery with IOLs. The results suggest that fibronectin may be the major extracellular protein responsible for the attachment of acrylate IOLs to the capsular bag. This may represent a true bioactive bond between the IOL and the lens epithelial cells, and between the IOL and the capsular bag. This may explain the reason for clinical observations of less posterior capsular opacification and lower capsulotomy rates with the soft hydrophobic acrylate material of AcrySof® IOLs compared to the other IOL materials studied.
153

Étude de l’imagerie amyloïde cérébrale et de l’élargissement des endosomes dans les cellules sanguines au cours de la maladie d’Alzheimer / Analysis of brain PiB positive amyloid deposits and endosome enlargement in blood cells, in Alzheimer's disease

Corlier, Fabian 24 September 2014 (has links)
Le diagnostic de la maladie d’Alzheimer (MA) s’appuie sur des critères clinico-biologiques combinant un déficit de la mémoire épisodique et un marqueur biologique (dosage dans le liquide céphalorachidien, imagerie nucléaire) indicateur des changements qui signent le début de la maladie. Un phénomène biologique précoce de la maladie est la production de dépôts du peptide amyloïde dont le principal site de production à partir de son précurseur, l’APP, est le compartiment endosomal. L’apparition dans le cerveau d’endosomes élargis précède celle des dépôts amyloïdes.Nous avons analysé deux marqueurs biologiques. D’abord la charge amyloïde cérébrale par fixation du ligand [PiB] en tomographie d’émission de positrons (TEP) dans le cerveau des malades atteints d’une atrophie corticale postérieure (ACP). Puis nous avons étudié les endosomes dans les cellules périphériques (leucocytes mononucléaires et fibroblastes) de patients MA, et dans des lignées lymphoblastoïdes (LCL) d’individus porteurs d’une trisomie 21 dont 45% développent une MA à l’âge de 60 ans (contre 3 % dans la population générale), principalement en raison de la présence d’une troisième copie du gène codant l’APP, localisé sur le chromosome 21. Nos travaux montrent des profils de marquage [PiB] similaires entre la MA et l’atrophie corticale postérieure (ACP) aussi bien en intensité qu’en topographie. L’étude des endosomes montre que les modifications du compartiment endosomal sont détectables en périphérie du système nerveux central et sont corrélées au marquage des dépôts amyloïdes cérébraux. Ces altérations pourraient constituer un outil de diagnostic à partir de prélèvements sanguins. / Alzheimer’s disease (AD) diagnostic is based on clinical and biological criteria, and is dependent on impairment of the episodic memory together with a marker of the underlying pathophysiologic process. One of the earliest events in AD pathology in the brain is formation of Amyloid deposits in the extracellular space. One of the main subcellular sites of amyloid-β (Aβ) production from amyloid precursor protein (APP) processing is the endosomal compartment. Appearance of endosomal abnormalities precede the formation of amyloid deposits, in the brain areas affected by disease progression in AD. In the present work we first studied brain amyloid load in patients with posterior cortical atrophy using [11C]PiB ligand retention in positron emitting tomography (PET). In a second part we studied the endosomal compartment in peripheral cells (fibroblasts and mononuclear leucocytes, PBMC) from AD patients, and in lymphoblastoid cell lines (LCL) from Down’s syndrome (DS) individuals where a third copy of amyloid-precursor-protein-coding gene located on chromosome 21 is known to initiate early Alzheimer’s pathology in most DS individuals. Our work shows similar profiles in topography and intensity of [PiB] binding in AD and posterior cortical atrophy (PCA), confirming underlying AD pathology in atypical focal presentations of AD. Analysis of endosomes yielded a significant increase in the frequency of cells with large endosomes in all analyzed cell types, and mean endosome volume correlated to [PiB] binding in PBMC. This result indicates that modifications of the endosomal compartment are seen in the periphery of central nervous system and may represent diagnostic tool from blood.
154

Conscious by Default : The Role of the Default Mode Network in Internal Awareness

Mattisson, Amanda January 2019 (has links)
Abstract In the 1990s researchers discovered task-deactivated regions in the human brain. Together, these areas make up the default mode network (DMN). It was originally proposed to act as a balancing mechanism between different brain systems, explaining the deactivations, but is now mostly studied with regards to internal awareness, such as daydreaming and mental imagery. The purpose of this thesis is to present a summary of DMN research, focusing on the network’s suggested role in internal awareness. This will be done by reviewing a wide variety of research that either explicitly or indirectly correlate default mode network features with aspects of consciousness and internal awareness. The subjective experience of being conscious have been a source of argument primarily among philosophers, but the qualities we feel are intimately linked to cognitive functions that are supported by the regions found in the DMN. Cognitive neuroscience may therefore be able to contribute to the concept of internal awareness and consciousness.
155

Mobilisering, statisk eller dynamisk stretch för ökad dorsalflexion i fotleden : en litteraturstudie / Mobilisation, static or dynamic stretch for increased ankle dorsiflexion : a review of current literature

Palmblad, Oscar, Daniel, Alvesköld January 2020 (has links)
Bakgrund: Fotleden används dagligen och en nedsatt fotledsrörlighet kan orsaka många problem för personer i vardagen. Knäböj är en rörelse som används både i vardagen samt i träningssammanhang och kräver en god dorsalflexion i fotleden. Det är därför värdefullt att som fysioterapeut veta vilken metod som ökar dorsalflexion inför ett rehabiliteringsprogram där knäböj ingår. Syfte: Sammanställa litteraturen gällande akuta effekter av dynamisk och statisk stretching samt posterior talocrural glide på dorsalflexion i talocruralleden hos friska individer, definierat som personer utan fysiologisk sjukdom eller trauma med eventuell påverkan på fotleden. Studien syftar även till att värdera graden av evidens för behandlingarna. Metod: Litteratursökning utfördes i databasen PubMed. Slutligen inkluderades åtta studier med sammanlagt 141 deltagare. Samtliga studier kvalitetsgranskades enligt PEDro scale, därefter användes SBU:s GRADE för evidensbedömning. Resultat: Statistisk signifikant ökning på dorsalflexion för samtliga metoder med liknande utslag på rörlighet, med liten fördel för statisk stretch. Kvalitetsgranskning enligt PEDro scale visar på att fem studier anses vara av måttlig till hög kvalitet och tre anses vara av låg kvalitet. Otillräckligt vetenskapligt underlag för posterior talocrural glide, statisk och dynamisk stretch på dorsalflexion. Konklusion: Statisk stretch, dynamisk stretch och posterior talocrural glide ökar dorsalflexionen efter minst två minuters behandling. Evidensen talar för att samtliga metoder ger liknande utfall på dorsalflexionen med en liten fördel för statisk stretch, men fler studier behövs för att bekräfta resultatet. / Background: Demands are put on the ankle daily. Limited ankle range of motion can present problems during daily activities. The squat is a movement performed both in everyday life as well as in the context of training and requires ample dorsiflexion of the ankle. Therefore, it is of value to physiotherapists to know which method should be used to increase dorsiflexion in a rehabilitation protocol where the squat is included. Objective: To provide an overview of the acute effects of static and dynamic stretching as well as posterior talocrural glide in healthy individuals without physiological diseases or trauma relating to the ankle. The study will also assess the level of evidence surrounding each of these methods. Method: The database PubMed was used to search for the included studies. A total of eight studies was included in this review, with a total of 141 participants. Study quality was judged using PEDro scale, after which SBU’s GRADE was used to determine the level of evidence for each method. Result: A statistically significant increases present for each of the methods, with similar outcomes on the dorsiflexion. Assessing the quality of the included studies with PEDro scale resulted in five studies of moderate to high quality and three of low quality. Evidence supporting posterior talocrural glide, static and dynamic stretching is deemed insufficient according to SBU’s GRADE. Conclusion: Dorsiflexion is increased after two minutes of static and dynamic stretching as well as posterior talocrural glide. The evidence suggests that similar increases are present with each method, with static stretch showing a slightly higher result. However further research is required to confirm the result.
156

Prótesis de rodilla. Análisis del beneficio clínico entre la conservación o resección del ligamento cruzado posterior

Serna-Berna, Ricardo 17 June 2019 (has links)
Antecedentes: La artroplastia total de rodilla es una de las intervenciones más eficientes y consolidadas en el campo de la cirugía ortopédica para el tratamiento de la artrosis de rodilla avanzada, cuando fracasan las medidas terapéuticas no quirúrgicas. En la actualidad, continúa la controversia con respecto a si el ligamento cruzado posterior debe mantenerse o resecarse durante el procedimiento quirúrgico. Objetivo: El objetivo de nuestro estudio, fue comparar los resultados clínicos con un seguimiento mínimo de 10 años entre los pacientes que fueron tratados con artroplastia primaria de rodilla con retención del ligamento cruzado posterior y los que fueron tratados con una artroplastia primaria de rodilla estabilizada posterior tras resección del ligamento cruzado posterior. Material y Métodos: Estudio de casos y controles de 268 pacientes que se sometieron a una artroplastia primaria de rodilla con retención del ligamento cruzado posterior, versus 211 pacientes con diseño estabilizado posterior, con el mismo sistema de artroplastia excepto en el mecanismo de poste-leva y con un seguimiento mínimo de 10 años. La evaluación clínica se realizó mediante la escala Knee Society System, el cuestionario Western Ontario y MacMasters Universities y Short-Form 12 , el rango de movilidad de la rodilla y grado de satisfacción del paciente. Resultados: Con ambos diseños protésicos, obtuvimos resultados clínicos exitosos sin encontrar diferencias significativas en las puntuaciones funcionales globales, del rango de movilidad y en las puntuaciones relacionadas con el paciente o su satisfacción. Además, la tasa de complicaciones y la supervivencia del implante fueron similares en ambos grupos. Conclusiones: En artrosis de rodilla con integridad del ligamento cruzado posterior, tanto la artroplastia primaria con retención del ligamento cruzado posterior como la artroplastia primaria postero-estabilizada, proporciona buenos resultados clínicos a 5 y 10 años, no encontrando la superioridad de un diseño sobre el otro. Ambos modelos protésicos se pueden usar esperando resultados satisfactorios a largo plazo y una alta supervivencia del implante.
157

Long-term Light-activated Drug Delivery Systems

He, Xingyu January 2020 (has links)
No description available.
158

Semi-Automated Detection of Bladder Neck Funneling and Measurement of Posterior Urethrovesical Angle in Females

Vandermolen, Megan 29 April 2022 (has links)
The pathophysiology of stress urinary incontinence is poorly understood but bladder neck funneling (BNF) and posterior urethrovesical angle (PUVA) enlargement have been implicated. Methods to measure these phenomena are poorly established. The aim of this thesis was to develop and evaluate a semi-automated method to analyze BNF and PUVA from ultrasound images acquired transperineally and test its repeatability and concurrent validity compared to manual segmentation. Agreement between the semi-automated and manual methods was assessed by kappa statistics and intraclass correlation coefficients (ICCs). The repeatability of detection of BNF using the semi-automated approach was almost perfect (ĸC = 1.00 (p<0.001)), while the reliability of semi-automated detection of PUVA was good (ICC(3,1) = 0.860 (0.784 – 0.910)). Concurrent validity of BNF classification was almost perfect (ĸL = 1.00 (p<0.001)), while PUVA estimation was moderate (ICC(2,1) = 0.610 (0.514 – 0.705)). The method presented here is an acceptable proof of concept; further development is recommended.
159

Neuropeptide W-Immunoreactivity in the Hypothalamus and Pituitary of the Rat

Dun, Siok L., Brailoiu, G. Cristina, Yang, Jun, Chang, Jaw Kang, Dun, Nae J. 02 October 2003 (has links)
Neuropeptide W-23 (NPW23) and neuropeptide W-30 (NPW30) are 23- and 30-amino acid peptides recently isolated from the porcine hypothalamus. Immunohistochemical studies using a rabbit polyclonal antiserum against the rat NPW23 peptide revealed a limited distribution in the rat brain. NPW23-immunoreactive (irNPW) cells were detected in the paraventricular nucleus (PVH), mainly in the parvocellular division, supraoptic nucleus (SO), accessory neurosecretory nuclei, dorsal and lateral hypothalamic areas, perifornical nucleus, arcuate nucleus, and anterior and posterior pituitary; whereas, irNPW fibers were noted in the PVH and SO, retrochiasmatic nucleus, dorsal and lateral hypothalamic areas, median eminence, amygdala, and posterior pituitary. The pattern of distribution of irNPW in the hypothalamus corroborates a possible role of NPW on prolactin release and feeding behavior reported by others.
160

Parasympathetic Control of the Heart. III. Neuropeptide Y-Immunoreactive Nerve Terminals Synapse on Three Populations of Negative Chronotropic Vagal Preganglionic Neurons

Gray, Alrich L., Johnson, Tannis A., Lauenstein, Jean Marie, Newton, Stephen S., Ardell, Jeffrey L., Massari, V. John 01 June 2004 (has links)
The vagal postganglionic control of cardiac rate is mediated by two intracardiac ganglia, i.e., the sinoatrial (SA) and posterior atrial (PA) ganglia. Nothing is known about the vagal preganglionic neurons (VPNs) that innervate the PA ganglion or about the neurochemical anatomy of central afferents that innervate these VPNs. These issues were examined using light microscopic retrograde labeling methods and dual-labeling electron microscopic histochemical and immunocytochemical methods. VPNs projecting to the PA ganglion are found in a narrow column exclusively in the ventrolateral nucleus ambiguus (NA-VL). These neurons are relatively large (37.6 ± 2.7 μm by 21.3 ± 3.4 μm) with abundant cytoplasm and intracellular organelles, rare somatic and dendritic spines, round uninvaginated nuclei, and myelinated axons. Previous physiological data indicated that microinjections of neuropeptide Y (NPY) into the NA-VL cause negative chronotropic effects. The present morphological data demonstrate that NPY-immunoreactive nerve terminals formed 18 ± 4% of the axodendritic or axosomatic synapses and close appositions on VPNs projecting to the PA ganglion. Three approximately equal populations of VPNs in the NA-VL were retrogradely labeled from the SA and PA ganglia. One population each projects to the SA ganglion, the PA ganglion, or to both the SA and PA ganglia. Therefore, there are both shared and independent pathways involved in the vagal preganglionic controls of cardiac rate. These data are consistent with the hypothesis that the central and peripheral parasympathetic controls of cardiac rate are coordinated by multiple potentially redundant and/or interacting pathways and mechanisms.

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