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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.
371

Depression, Psychological Distress and Breast and Cervical Cancer Screening: A Population-based Study in Ontario Women

Vigod, Simone Natalie 31 May 2011 (has links)
Purpose: The objective of this study was to investigate both depression and psychological distress as determinants of breast and cervical cancer screening. Methods: Ontario female respondents to the Canadian Community Health Survey version 1.2 (2002) were assessed for both Major Depressive Disorder (World Mental Health-Composite International Diagnostic Interview for depression) and psychological distress (Kessler 6-item Distress Scale (K6)>/= 8). Respondents eligible for screening (N=4042 for cervical cancer; N=1403 for breast cancer) were linked to Ontario administrative health service data to prospectively ascertain screening outcomes. Results: Women with K6 >/= 8 had reduced breast cancer screening compliance in adjusted analyses (AOR 0.63, 95% CI 0.40-0.97). The association between K6 >/= 8 and cervical cancer screening approached significance in women over age 40 (AOR=0.65, 95%CI 0.41-1.04). Conclusion: Decreased likelihood of screening in women with clinically significant psychological distress suggests that attention to adequacy of preventive services is a potential target for intervention.
372

El implante discal cervical como alternativa a la artrodesis en el tratamiento quirúrgico de la cervicoartrosis

Lafuente, Jesús 01 April 2004 (has links)
Objetivo: Evaluación de la prótesis de Bryan como alternativa a la artrodesis en el tratamiento de la espondilosis cervical. Materiales y métodos: 54 pacientes consecutivos con radiculopatía o mielopatía fueron intervenidos quirúrgicamente de discectomía cervical con implantación de la prótesis discal cervical. Dichos implantes presentan medidas variables que van de 14 a 18 mm. El seguimiento se realizo a las seis semanas, seis meses y un ano y consistió en una evaluación del dolor (VAS), la SF-36 y el "neck dissability index" (NDI). Los resultados totales fueron combinados para obtener un resultado clínico basado en los criterios de Odom (excelente, bueno, aceptable y malo). La evaluación radiológica consistió en el análisis del movimiento así como de la estabilidad y la subsidencia de la prótesis. Este análisis se realizo a través de un radiólogo independiente. Además estudiamos la asociación de un marcador genético como la apolipoproteína "e4" como factor de riesgo en pacientes intervenidos de espondilosis cervical mielopática.Resultados: Habían 33 varones y 21 hembras. La edad media fue de 47.8 años (DE=10.9). Se observo una diferencia estadísticamente muy significativa comparando los controles preoperatorios con los postoperatorios en las tres escalas de resultados. : VAS (Z=7.1, p<0.0001), SF36MCS (Z=-5.9, p<0.0001), SF36PCS (Z=-5.8, p<0.0001) y NDI (Z=7.8, p<0.0001). Del mismo modo se observo una diferencia estadísticamente significativa entre la edad y los resultados quirúrgicos; la edad y la estancia intrahospitalaria; la presentación clínica y la duración de los síntomas y con la duración de los síntomas y los resultados quirúrgicos.Los pacientes con el genotipo de la apolipoproteina e4 debutaron a una edad mas temprana (Edad media 49 años) versus 59 años en el grupo restante (t-test p<0.05). Los pacientes con el alelo e4, obtuvieron peores resultados postoperatoriamente, según las escalas de resultados: Prueba del caminar, (_2 p<0.01), EMS (t-test p<0.009), JOA (t-test p<0.03), Nurick's class (_2 p< 0.02), Ranawat class (t-test p<0.03 CME. Además, aquellos con el gen de la Apo "e4" parecen sufrir una progresión de la enfermedad más rápidamente según las prueba del caminar (_2 p< 0.03) y Nurick's' class (_2 p< 0.05).Aquellos pacientes con el gen de la apolipoproteína "e4" tenían una compresión medular menor que aquellos sin el gen de la Apo "e4" (__, P<0.01)Conclusiones: La prótesis de Bryan ha demostrado ser fiable y seguirá en el tratamiento de los pacientes aquejados de espondilosis cervical. A pesar de ello, para obtener resultados mas objetivos que sean capaces de determinar que la artroplastia es superior a la artrodesis a corto y largo plazo, nosotros proponemos el estudio CEDRIC, que consiste en un estudio prospectivo , randomizado con randomización intraoperativa bien a artroplastia o a artrodesis mediante caja íntersomática. / Objective: Evaluation of the Bryan disc arthroplasty as an alternative to arthrodesis in the treatment of cervical spondylosis.Material and methods: 54 consecutive patients with either radiculopathy or myelopathy had a cervical discectomy with implantation of the cervical disc prosthesis. The implants have a variable measure from 14 to 18 mm of diameter. Follow-up was arranged at 6 weeks, 6 months and 1 year and included Visual Analogue Scale (VAS), the Short Form 36 (SF 36) and the Neck disability index (NDI). The results were categorized according to the modified Odom's criteria: excellent, good, fair and poor. Radiological evaluation looked at movement, stability and subsidence of the prosthesis, by an independent radiologist. We also studied the presence of a genetic marker "apolipoprotein e4" as a risk factor in the outcome of cervical spondylotic myelopathy. Results: There were 33 male and 21 female. The mean age was 47.8 years (SD=10.9). A highly significant difference was found for all 3 outcome measures comparing the preoperative with the post-operative follow-up values: VAS (Z=7.1, p<0.0001), SF36MCS (Z=-5.9, p<0.0001), SF36PCS (Z=-5.8, p<0.0001) and NDI (Z=7.8, p<0.0001). There were also found statistical significance between age and surgical outcome; age and hospital stay; clinical presentation and duration of symptoms and duration of symptoms with surgical outcome.Patients with apolipoprotein e4 genotype presented with the disease earlier (mean age 49 years) versus 59 years in the rest of the group (t-test p< 0.05). Patients with positive Apo e genotype had poorer outcome at six months of surgery as seen with: walking test (_2 p<0.01), EMS (t-test p<0.009), JOA (t-test p<0.03), Nurick's class (_2 p< 0.02), Ranawat class (t-test p<0.03). Those patients with Apo e4 allele also seemed to suffer from further progression of the disease earlier as one year outcomes were worse for walking test (_2 p< 0.03) and Nurick's' class (_2 p< 0.05)Radiological analyses revealed that those individuals with Apo E4 allele were rendered myelopathic with less compression than those without the gene. (_2 p< 0.01)Conclusion: The Bryan cervical disc replacement has shown to be reliable and safe for the treatment of patients with cervical spondylosis. However in order to find objective results which will determine if the arthroplasty is better than arthrodesis in the short and the long term, we propose the CEDRIC trial, which consists in a prospective randomized clinical trial with intraoperative randomization to either an artificial disc or a interbody cage.
373

Numerical Modelling of the Human Cervical Spine in Frontal Impact

Panzer, Matthew January 2006 (has links)
Motor vehicle accidents continue to be a leading cause of cervical spine injury despite a conscientious effort to improve occupant safety. Accurately predicting occupant head and neck response in numerical crash simulations is an essential part of the process for developing better safety solutions. <br /><br /> A biofidelic model of the human cervical spine was developed with a focus on accurate representation of the cervical spine at the local tissue level. These tissues were assembled to create a single segment model that was representative of <em>in vitro</em> spine in quasi-static loading. Finally, the single segment models were assembled to create a full cervical spine model that was simulated in dynamic loading and compared to human volunteer response. <br /><br /> Models of each segment were constructed from the basic building blocks of the cervical spine: the intervertebral disc, the vertebrae, the ligaments, and the facet joints. Each model was simulated in all modes of loading and at different levels of load. The results of the study indicate that the cervical spine segments performed very well in flexion, compression, and tension. Segment response to lateral bending and axial rotation was also good, while response in extension often proved too compliant compared to the experimental data. Furthermore, the single segment models did not fully agree with the experimental shear response, again being more compliant. <br /><br/> The full cervical spine model was assembled from the single segment models incorporating neck musculature. The model was simulated dynamically using a 15 G frontal impact test. Active muscles were used to simulate the response of the human volunteers used in the study. The response of the model was in reasonable agreement with the experimental data, and compared better than current finite element cervical spine models. Higher frequency oscillation caused most of the disagreement between the model and the experimental data, which was attributed to a lack of appropriate dynamic material properties of the soft tissues of the spine. In addition, a study into the active properties of muscle indicated that muscle response has a significant influence on the response of the head. <br /><br /> A number of recommendations were proposed that would improve the biofidelity of the model. Furthermore, it was recommended that the future goal of this model would be to implement injury-predicting capabilities through the development of advance material models.
374

Numerical Modelling of the Human Cervical Spine in Frontal Impact

Panzer, Matthew January 2006 (has links)
Motor vehicle accidents continue to be a leading cause of cervical spine injury despite a conscientious effort to improve occupant safety. Accurately predicting occupant head and neck response in numerical crash simulations is an essential part of the process for developing better safety solutions. <br /><br /> A biofidelic model of the human cervical spine was developed with a focus on accurate representation of the cervical spine at the local tissue level. These tissues were assembled to create a single segment model that was representative of <em>in vitro</em> spine in quasi-static loading. Finally, the single segment models were assembled to create a full cervical spine model that was simulated in dynamic loading and compared to human volunteer response. <br /><br /> Models of each segment were constructed from the basic building blocks of the cervical spine: the intervertebral disc, the vertebrae, the ligaments, and the facet joints. Each model was simulated in all modes of loading and at different levels of load. The results of the study indicate that the cervical spine segments performed very well in flexion, compression, and tension. Segment response to lateral bending and axial rotation was also good, while response in extension often proved too compliant compared to the experimental data. Furthermore, the single segment models did not fully agree with the experimental shear response, again being more compliant. <br /><br/> The full cervical spine model was assembled from the single segment models incorporating neck musculature. The model was simulated dynamically using a 15 G frontal impact test. Active muscles were used to simulate the response of the human volunteers used in the study. The response of the model was in reasonable agreement with the experimental data, and compared better than current finite element cervical spine models. Higher frequency oscillation caused most of the disagreement between the model and the experimental data, which was attributed to a lack of appropriate dynamic material properties of the soft tissues of the spine. In addition, a study into the active properties of muscle indicated that muscle response has a significant influence on the response of the head. <br /><br /> A number of recommendations were proposed that would improve the biofidelity of the model. Furthermore, it was recommended that the future goal of this model would be to implement injury-predicting capabilities through the development of advance material models.
375

Cervical Spine Segment Modeling at Traumatic Loading Levels for Injury Prediction

DeWit, Jennifer Adrienne January 2012 (has links)
Cervical spine injury can range from minor to severe or fatal, where severe injuries can result in incomplete or complete quadriplegia. There are close to 45,000 Canadians currently affected by paralysis due to traumatic spinal cord injury (tSCI) with an estimated 1700 new cases each year. The majority of tSCI occur in automotive collisions, and current methods for injury prediction are limited to predicting the likelihood for occupant injury but lack the detail to predict the specific injury and location at the tissue level. This research focused on major injuries associated with high impact automotive collisions such as rollover type collisions. Although whiplash is an injury commonly associated with automotive collisions, it was not considered for this study based on the low risk of neurological impairment. The goal of this study was to develop a cervical spine segment finite element model capable of predicting severe injuries such as ligament tears, disc failure, and bone fracture. The segment models used in this study were developed from previous cervical spine segment models representative of a 50th percentile male. The segment models included the vertebrae, detailed representations of the disc annulus fibres and nucleus, and the associated ligaments. The original model was previously verified and validated under quasi-static loading conditions for physiological ranges of motion. To accomplish the objectives of this research, the original models were modified to include updated material properties with the ability to represent tissue damage corresponding to injuries. Additional verification of the model was required to verify that the new material properties provided a physically correct response. Progressive failure was introduced in the ligament elements to produce a more biofidelic failure response and a tied contact between the vertebral bony endplates and the disc was used to represent disc avulsion. To represent the onset of bone fracture, a critical plastic strain failure criterion was implemented, and elements exceeding this criterion were eroded. The changes made to the material models were based on experimental studies and were not calibrated to produce a specific result. After verifying the modifications were implemented successfully, the models were validated against experimental segment failure tests. Modes of loading investigated included tension, compression, flexion, extension and axial rotation. In each case, the simulated response of the segment was evaluated against the average failure load, displacement at failure, and the observed injuries reported in the experimental studies. Additionally, qualitative analysis of elevated stress locations in the model were compared to reported fracture sites. Overall, the simulations showed good agreement with the experimental failure values, and produced tissue failure that was representative of the observed tissue damage in the experimental tests. The results of this research have provided a solid basis for cervical spine segment level injury prediction. Some limitations include the current implementation of bone fracture under compressive loads, and failure within the annulus fibrosus fibres of the disc should be investigated for future models. In addition to material model modifications, further investigation into the kinetics and kinematics of the upper cervical spine segment are important to better understand the complex interactions between the bone geometry and ligaments. This would give insight into the initial positioning and expected response in subsequent models. Future research will include integrating the current segment-level failure criteria into a full cervical spine model for the purpose of predicting severe cervical spine injury in simulated crash scenarios, with future applications in sports injury prevention and protective equipment.
376

The Biomechanics of the Perinatal, Neonatal and Pediatric Cervical Spine: Investigation of the Tensile, Bending and Viscoelastic Response

Luck, Jason Frederick January 2012 (has links)
<p>Pediatric cervical spinal injuries are associated with high morbidity and mortality. Cervical injuries observed in the pediatric population appear to be age dependent with younger children experiencing more upper cervical level injuries compared to increased lower level cervical injury patterns to older children. The majority of pediatric cervical spinal injuries are motor vehicle crash related. Current progress in child occupant protection, including increased and proper restraint usage continues to reduce serious injury and fatalities to child occupants. However, improper restraint usage and incorrect child seating location, especially with children transitioning from rear-facing child restraints to forward-facing restraints is still a concern. Continued reductions in serious injury and fatalities to child occupants in survivable motor vehicle crashes will be based on continued education and improvements in child anthropometric test devices, child computational injury models and child restraint system design. Improvements in all of these categories are dependent on an improved understanding of the developmental biomechanics of the human cervical spine. Currently, limited data exist on human child neck biomechanics and none of the current cadaveric work has evaluated the biomechanical response over the entire age spectrum from birth to young adulthood. Numerous surrogate studies exist and have formed the basis of child injury criteria and developmental biomechanics, but have not been assessed in relation to the response of the pediatric human cervical spine. The current work investigates the biomechanics of the osteoligamentous human cervical spine from birth to young adulthood under tensile and bending loading environments. Tensile low-load and load-to-failure stiffness, load-to-failure, and flexion-extension bending stiffness increased with age. Tensile normalized displacement at failure and total bending low-load range of motion decreased with age. Viscoelastic rate effects are present in the pediatric cervical spine and are modeled with quasi-linear viscoelasticity. Peak load and loading energy increases with increased loading rate, while hysteresis energy is rate insensitive at lower loading rates, but increases at higher rates of loading. These data establish structural response behavior and injury thresholds for the osteoligamentous cervical spine by age. Additionally, they provide human data to assess the appropriateness of current surrogate models and current scaling techniques associated with these models. Finally, these data provide human response by age useful in progressing the biofidelity of computational and physical models for child occupant protection.</p> / Dissertation
377

The Role of Chibby as a Potential Tumor Suppressor Gene in Human Cervical Cancer

Huang, Yen-Lin 02 September 2010 (has links)
The Wnt signaling pathway is highly conserved and participates in many important cellular functions including differentiation, embryonic development and tissue generations. £]-catenin, the central mediator of the Wnt signaling, interacts with the TCF/LEF family of transcription factors in the nucleus and initiates downstream gene transcription. In addition, £]-catenin is known as a proto-oncogene implicated in numerous cancers including colorectal, cervical, endometrial and skin cancer. Chibby (Cby) is evolutionarily conserved in many species and acts as a repressor of Wnt/£]-catenin signaling. In our previous study, we have established that Cby over-expression attenuated £]-catenin translocation to nucleus and its transcriptional activity. Thus, it was hypothesized that Cby may possess potential tumor suppressing capabilities. In the present study, we first explored endogenous Cby expression status in human cervical cancer cells: HeLa and SiHa cell lines. It was observed that Cby mRNA and protein levels were significantly down-regulated in both cancer lines compared with primary cervical cells. We then conducted functional assays of tumorigenicity on both cells using adenoviral-encoded Cby and its NLS (nuclear localization signaling) deleted variant (Cby∆NLS). It was found that gene delivery of Cby or Cby∆NLS inhibited the proliferation, invasiveness, and colony forming in HeLa and SiHa cells. Immunofluorescent analysis revealed that Cby or Cby∆NLS gene transfer reduced the expression of Ki-67, a cell proliferative marker. Furthermore, Cby or Cby∆NLS restoration induced apoptosis and perturbed cell cycle progression in both cervical cancer cells. Finally, Cby over-expression decreases the expression of £]-catenin/TCF4 regulated genes such as c-myc and PCNA, which might contributed to the anti-neoplastic mechanism for Cby in cervical cancer cell lines. Our results strongly suggest that Cby may serve as a tumor suppressor gene during cervical carcinogenesis, and may facilitate in creation of new therapeutic methods.
378

18 YEARS OF CONFORMATION RADIOTHERAPY AT NAGOYA UNIVERSITY HOSPITAL

ISHIGAKI, TAKEO, OBATA, YASUNORI, MURAO, TAKAYUKI, ITO, YOSHlYUKI, HORlKAWA, YOSHIMI, YAMADA, TETSUYA, KODAIRA, TSUYOSHI, KOBAYASHI, HIDETOSHI 29 March 1996 (has links)
No description available.
379

Cervical Spine Injuries - Numerical Analyses and Statistical Survey

Brolin, Karin January 2002 (has links)
<p>Injuries to the neck, or cervical region, are very importantsince there is a potential risk of damage to the spinal cord.Any neck injury can have devastating if not life threateningconsequences. High-speed transportation as well as leisure-timeadventures have increased the number of serious neck injuriesand made us increasingly aware of its consequences.Surveillance systems and epidemiological studies are importantprerequisites in defining the scope of the problem. Thedevelopment of mechanical and clinical tools is important forprimary prevention of neck injuries.</p><p>Thus, the main objectives of the present doctoral thesisare:- To illustrate the dimension of cervical injuries inSweden,- To develop a Finite Element (FE) model of the uppercervical spine, and- To study spinal stability for cervical injuries.</p><p>The incidence studies were undertaken with data from theinjury surveillance program at the Swedish National Board ofHealth and Welfare. All in-patient data from Swedish hospitals,ranging over thirteen years from 1987 to 1999, were analyzed.During this period 14,310 nonfatal and 782 fatal cervicalinjuries occurred. The lower cervical spine is the mostfrequent location for spinal trauma, although, this changeswith age so that the upper cervical spine is the most frequentlocation for the population over 65 years of age. The incidencefor cervical fractures for the Swedish population decreased forall age groups, except for those older than 65 years of age.The male population, in all age groups, has a higher incidencefor neck fractures than females. Transportation relatedcervical fractures have dropped since 1991, leaving fallaccidents as the sole largest cause of cervical trauma.</p><p>An anatomically detailed FE model of the human uppercervical spine was developed. The model was validated to ensurerealistic motions of the joints, with significant correlationfor flexion, extension, lateral bending, axial rotation, andtension. It was shown that an FE-model could simulate thecomplex anatomy and mechanism of the upper cervical spine withgood correlation to experimental data. Three studies wereconducted with the FE model. Firstly, the model of the uppercervical spine was combined with an FE model of the lowercervical spine and a head model. The complete model was used toinvestigate a new car roof structure. Secondly, the FE modelwas used for a parameter study of the ligament materialcharacteristics. The kinematics of the upper cervical spine iscontrolled by the ligamentous structures. The ligaments have tomaintain spinal stability while enabling for large rotations ofthe joints. Thirdly, the FE-model was used to study spinalinjuries and their effect on cervical spinal stability inflexion, extension, and lateral bending. To do this, the intactupper cervical spine FE model was modified to implementruptures of the various spinal ligaments. Transection of theposterior atlantooccipital membrane, the ligametum flavum andthe capsular ligament had the most impact on flexion, while theanterior longitudinal ligament and the apical ligamentinfluenced extension.</p><p>It is concluded that neck injuries in Sweden is a problemthat needs to be address with new preventive strategies. It isespecially important that results from the research on fallaccidents among the elderly are implemented in preventiveprograms. Secondly, it is concluded that an FE model of thecervical region is a powerful tool for development andevaluation of preventive systems. Such models will be importantin defining preventive strategies for the future. Lastly, it isconcluded that the FE model of the cervical spine can increasethe biomechanical understanding of the spine and contribute inanalyses of spinal stability.</p>
380

Spina accresco mechanicus : on the developmental biomechanics of the spine /

Nuckley, David John, January 2002 (has links)
Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 153-165).

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