Electromyographic (EMG) activity versus bite force was studied during a gradually increased isometric contraction up to maximal effort for patients with painful masseter muscles and referents. The masseter muscle, the anterior temporal muscle and the descending part of the trapezius muscle were chosen for the recordings. Bite force was registered with a bite force sensor placed between the first molars. The effects of double blind intramuscular injections of lidocaine and saline in the patients' masseter muscle were evaluated by EMG versus bite force and by assessments of discomfort. EMG activity during unilateral chewing was compared in terms of relative masticatory force between referents and patients by amplitude probability distribution analysis. Regression analyses showed intra-individually steeper slopes for high force levels than for low force levels for the masseter muscle. This was not observed for the anterior temporal muscle. These differences in slopes of the EMG versus force regressions for the masseter muscle and the anterior temporal muscle could be due to differences in recruitment pattern. The same intra-individual relationship between low and high force levels was found for referents and patients. An increased activity, especially among the patients, was found for the descending part of the trapezius muscle during stronger activity of the mandibular elevators. The EMG versus force relationship for low force levels of the masseter muscle was less steep after an intramuscular injection of lidocaine but not after saline. Both solutions for injection had a positive effect on the patients' assessments of discomfort one week after the injection. Three days after injection the patients who received lidocaine experienced a reduction in muscular discomfort. This reduction was not found among patients receiving saline. The amplitude probability distribution analysis revealed that the patients used greater relative masticatory forces than the referents during the chewing of an almond for all probability levels analysed below the peak load of the masseter muscles. Rough estimates of the peak masticatory forces in Newton (N) were for chewing an almond 364 N (referents); 373 N (patients) and for gum-chewing 239 N (referents); 238 N (patients) as regards the masseter muscle. The values were similar for the anterior temporal muscle. / digitalisering@umu

En esta tesis se aborda el estudio de la grasa intramuscular como característica determinante de la calidad de la carne para ser utilizado en programas genéticos. El conejo se plantea no sólo por su interés como especie ganadera sino como modelo en otras especies. Este estudio se divide en tres experimentos, cada uno de ellos representa cada uno de los tres objetivos específicos de esta tesis: 1. Estudiar la variabilidad genética entre líneas de conejo de factores ligados directamente a la deposición de grasa tanto en músculo como en tejido adiposo, como son las enzimas que participan en la síntesis y degradación de la grasa y en la composición en ácidos grasos. 2. Puesta a punto de una calibración NIRS para estimar grasa intramuscular y la evaluación de su uso en programas de selección en conejo. 3. Selección divergente por grasa intramuscular. Estudio de las posibilidades de éxito de la selección por grasa intramuscular y conocer las relaciones genéticas entre caracteres examinando la respuesta correlacionada. Supone el inicio de una nueva línea de investigación en metabolismo lipídico, que puede servir tanto a la producción de conejo como animal de carne como al uso del conejo como modelo experimental. Es la primera vez que se propone un experimento de selección divergente por grasa intramuscular. Este experimento permitirá conocer mejor las relaciones genéticas entre la grasa intramuscular, la grasa de la canal, así como las relaciones con otros caracteres productivos. El conocimiento de estas relaciones genéticas va a ser fundamental para futuros programas de mejora genética en todas las especies ganaderas. / Zomeño Segado, C. (2013). ANÁLISIS GENÉTICO DE LA GRASA INTRAMUSCULAR EN CONEJO-GENETIC ANALISYS OF INTRAMUSCULAR FAT IN RABBITS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/31121 / TESIS

[ES] La selección divergente puede cambiar las frecuencias de los marcadores genéticos en direcciones opuestas, produciéndose frecuencias alélicas intermedias en estos marcadores cuando ambas líneas divergentes son consideradas conjuntamente en los análisis genéticos. Por lo tanto, los experimentos de selección divergente aumentan el poder de detección para estudios de asociación de genoma completo (GWAS) y para estudios de escaneo genómico por medio de métodos de huellas de selección. GWASs bayesianos, utilizando el modelo Bayes B, se implementaron para analizar datos genómicos de los caracteres de tamaño de camada del experimento de capacidad uterina con 181 hembras. Las asociaciones fueron evaluadas calculando los factores de Bayes para cada SNP, y calculando los porcentajes de la varianza genómica para cada ventana no solapada de 1-Mb. Los GWASs descubrieron SNPs asociados con el número total de gazapos al parto y los embriones implantados. Además, se revelaron regiones genómicas relevantes para el número total de gazapos al parto (1 región), el número de nacidos vivos (1 región), los embriones implantados (3 regiones) y la tasa de ovulación (5 regiones). Los porcentajes de varianza genómica que explicaban los anteriores caracteres de tamaño de camada fueron 39,48%, 10,36%, 37,21% y 3,95%, respectivamente, en un modelo que excluye el efecto línea; y 7.36%, 1.27%, 15.87% y 3.95%, respectivamente, en un modelo con el efecto línea. La región genómica localizada en el cromosoma del conejo (OCU) 17 en 70.0 - 73.3 Mb se consideró como un nuevo locus de carácter cuantitativo (QTL) asociado a caracteres reproductivos en conejos, ya que esta región fue encontrada solapada para el número total de gazapos al parto, el número de nacidos vivos y los embriones implantados. El gen de la proteína morfogenética ósea 4, BMP4, es el principal gen candidato prometedor dentro del nuevo QTL. Una combinación de GWASs fueron implementados para analizar los datos genómicos del experimento de la grasa intramuscular con 480 conejos. Los métodos de GWASs incluyeron un método bayesiano, modelo Bayes B; y un método frecuentista, regresiones de marcadores únicos con los datos ajustados por el parentesco genómico. Este estudio reveló cuatro regiones genómicas relevantes en OCU1 (1 región), OCU8 (2 regiones) y OCU13 (1 región) asociadas con la grasa intramuscular. La región asociada más importante estaba en OCU8 en 24.59 - 26.95 Mb, y explicó el 7.34% de la varianza genómica. El bajo porcentaje explicado por las principales regiones genómicas relevantes indica un gran componente poligénico para la grasa intramuscular. Los análisis funcionales recuperaron genes vinculados con las rutas y funciones de los metabolismos de energía, carbohidratos y lípidos. Además, se realizó un estudio de escaneo genómico usando conejos del experimento de selección divergente para grasa intramuscular, y usando tres métodos de firmas de selección: índice de fijación de Wright (Fst), coeficiente de verosimilitud compuesto entre poblaciones (XP-CLR) y extensión de homocigosidad de los haplotipos entre poblaciones (XP-EHH). Los resultados mostraron múltiples huellas de selección en todo el genoma del conejo. Ninguna de estas huellas de selección concuerda con las regiones genómicas asociadas con la grasa intramuscular, provenientes de los resultados de los GWASs. En síntesis, los resultados de ambos experimentos, GWASs y el estudio de escaneo genómico, sugieren que la arquitectura genómica de la grasa intramuscular en el conejo parece ser altamente poligénica y sus variantes causales serían apenas detectables. Este estudio demuestra que la detección de variantes causales y marcadores genéticos asociados depende de las hipotéticas arquitecturas genómicas de los caracteres, independientemente de las exitosas respuestas logradas en los dos experimentos de selección divergente. Hasta la fecha, estos hallaz / [CAT] La selecció divergent pot alterar les freqüències dels marcadors genètics en direccions oposades, donant lloc a freqüències al·lèliques intermèdies quan les dos línies divergents es consideren conjuntament en els anàlisis genètics. Per tant, els experiments de selecció divergents augmenten el poder de detecció en estudis d'associació de genoma ampli (GWAS) i en estudis d'exploració genòmica a través de mètodes de signatures de selecció. GWASs bayesians, utilitzant el model Bayes B, es van implementar per a analitzar dades genòmiques de caràcters de grandària de ventrada de l'experiment de capacitat uterina amb 181 conilles femelles. Les associacions es van provar calculant els factors de Bayes per a cada SNP, i calculant els percentatges de la variància genòmica per a cada finestra no superposada d'1-Mb. Els GWASs van descobrir SNPs associats amb el número total de llorigons al part i els embrions implantats. A més, es van revelar regions genòmiques rellevants per al número total de llorigons al part (1 regió), el número de nascuts vius (1 regió), els embrions implantats (3 regions) i la taxa d'ovulació (5 regions). Els percentatges de variància genòmica que explicaven els anteriors caràcters de grandària de ventrada van ser 39,48%, 10,36%, 37,21% i 3,95%, respectivament, sota un model que exclou l'efecte de línia; i 7.36%, 1.27%, 15.87% i 3.95%, respectivament, sota un model amb efecte de línia. La regió genòmica situada en el cromosoma del conill (OCU) 17 en 70.0 - 73.3 Mb es va considerar com un nou locus de caràcters quantitatius (QTL) associat a caràcters reproductius en conills, ja que aquesta regió es va superposar per al número total de llorigons al part, el número de nascuts vius i els embrions implantats. El gen de la proteïna morfogenètica òssia 4, BMP4, és el principal gen candidat prometedor dins del nou QTL. Una combinació de GWASs es van implementar per a analitzar les dades genòmiques de l'experiment del greix intramuscular amb 480 conills. Els mètodes GWASs van incloure un mètode bayesià, model Bayes B; i un mètode frecuentista, regressions de marcadors únics amb les dades ajustades pel parentiu genòmico. Aquest estudi va revelar quatre regions genòmiques rellevants en OCU1 (1 regió), OCU8 (2 regions) i OCU13 (1 regió) associades amb el greix intramuscular. La regió associada més important estava en OCU8 en 24.59 - 26.95 Mb, i va explicar el 7.34% de la variància genòmica. El baix percentatge explicat per les principals regions genòmiques rellevants indica un gran component poligènic per al greix intramuscular. Els anàlisis funcionals van recuperar gens relacionats amb les rutes i la funció d'energia, metabolismes de carbohidrats i lípids. A més, es va realitzar un estudi d'exploració del genoma usant conills de l'experiment de selecció divergent per a greix intramuscular, i usant tres mètodes de signatures de selecció: índex de fixació de Wright (Fst), coeficient de versemblança compost entre poblacions (XP-CLR) i extensió de homocigosidad dels haplotipos entre poblacions (XP-EHH). Els resultats van mostrar múltiples petjades de selecció en tot el genoma del conill. Cap d'aquestes petjades de selecció concorda amb les regions genòmiques associades a partir dels resultats dels GWASs. En síntesi, els resultats dels dos experiments, GWASs i estudi d'exploració del genoma, suggereixen que l'arquitectura genòmica del greix intramuscular en el conill sembla ser altament poligènica i les seues variants causals serien a penes detectables. Aquest estudi demostra que la detecció de variants causals i marcadors genètics associats depèn de les hipotètiques arquitectures genòmiques dels caràcters, independentment de les respostes reeixides en els dos experiments de selecció divergents. Fins ara, aquestes troballes no tindrien implicacions valuoses per als programes de cria de conills. / [EN] Divergent selection can alter frequencies of genetic markers in opposite directions, leading to intermediate allelic frequencies when both divergent lines are jointly considered in the genetic analyses. Therefore, divergent selection experiments increase the detection power for genome wide association studies (GWAS) and for genomic scan studies through methods of selection signatures. Bayesian GWASs using Bayes B model was used to analyse genomic data of litter size traits of the uterine capacity experiment with 181 does. The associations were tested by computing Bayes factors for each SNP, and by computing percentages of the genomic variance for each 1-Mb non-overlapping window. The GWASs uncovered SNPs associated with total number born and implanted embryos. Moreover, relevant genomic regions were revealed for total number born (1 region), number born alive (1 region), implanted embryos (3 regions), and ovulation rate (5 regions). The percentages of genomic variance that accounted for these litter size traits were 39,48%, 10.36%, 37.21%, and 3.95%, respectively, under a model excluding line effect; and 7.36%, 1.27%, 15.87%, and 3.95%, respectively, under a model with line effect. The genomic region located on the rabbit chromosome (OCU) 17 in 70.0 - 73.3 Mb was deemed as a novel quantitative trait locus (QTL) of reproductive traits in rabbits, since this region was found overlapped for total number born, number born alive and implanted embryos. Bone morphogenetic protein 4 gene, BMP4, is the main promising candidate gene within the novel QTL. A combination of GWASs were performed for analysing the genomic data of the intramuscular fat experiment with 480 rabbits. The GWAS methods included a Bayesian method, Bayes B model; and a frequentist method, single marker regressions with the data adjusted by genomic relatedness. This study revealed four relevant genomic regions in OCU1 (1 region), OCU8 (2 regions) and OCU13 (1 region) associated with intramuscular fat. The most important associated region was on OCU8 in 24.59 - 26.95 Mb, and accounted for 7.34% of the genomic variance. The low percentage explained by the main relevant genomic regions indicates a large polygenic component for intramuscular fat. Functional analyses retrieved genes linked to pathways and function of energy, carbohydrate and lipid metabolisms. In addition, a genome scan study was performed using rabbits from the divergent selection experiment for intramuscular fat, and using three methods of selection signatures: Wright's fixation index (Fst), cross population composite likelihood ratio (XP-CLR) and cross population extended haplotype homozygosity (XP-EHH). The results showed multiple selection signatures across the rabbit genome. None of these selection signatures agreed with the associated genomic regions from GWAS findings. In synthesis, the results of both experiments, GWAS and genome scan study, suggest that the genomic architecture of intramuscular fat in rabbit seems to be highly polygenic and their causative variants would be hardly detectable. This study demonstrates that detection of causative variants and associated genetic markers depends on the hypothetical genomic architectures of traits, regardless of the successful responses attained in the two divergent selection experiments. Hitherto, these findings would not have worthwhile implications for the rabbit breeding programs. / Sosa Madrid, BS. (2020). Genomic analysis of divergently selected experimental lines in rabbit [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/141376 / TESIS

People with cerebral palsy (CP) may develop muscle contractures, which are defined as a loss of joint range due to an increase in passive muscle stiffness [1]. Computer models suggest that intramuscular fat can increase muscle stiffness [2]. There is evidence that children with spastic CP have elevated intramuscular fat fractions, but quantitative estimations of the intramuscular fat fraction are variable [1]. Therefore, a reliable method for in vivo quantification of intramuscular fat is required. The aim of this thesis was to compare two- and three-point Dixon fat-water separation methods, as well as the IDEAL algorithm for intramuscular fat quantification of the gastrocnemius medialis, for both children with CP and typically developed peers. As a reference standard, the water- and fat-only maps resulting from the Philips mDIXONXD turbo-spin-echo sequence were used (Ingenia CX, Philips Healthcare, The Netherlands). It was found that neither of the methods can compare to the reference standard, which is probably due to poor performance of the phase unwrapping algorithm applied on this data. Further studies need to be done in order to better quantify the phase error in multi-echo Dixon MRI.

No description available.

Human rotavirus (HRV) and human norovirus (HuNoV) are the most common causative agents of acute gastroenteritis- (AGE) related morbidity and mortality around the world. Gnotobiotic (Gn) pigs are the ideal large-animal model that allows for accurate, and precise, preclinical evaluation of vaccine efficacy. Similarities in gastrointestinal anatomy, physiology, and immune system allows for direct translation of results from Gn pigs to humans. Commercially available HRV vaccines perform significantly poorer in low- and middle- income countries as compared with developed countries. Non-replicating rotavirus vaccines (NRRVs) have been proposed as a viable solution to the problems facing currently available live-, attenuated oral vaccines and evaluation of a NRRV was the first research project in this dissertation. Three doses of a novel parenterally administered nanoparticle-based RV vaccine, P24-VP8*, adjuvanted with Al(OH)3 adjuvant, was able to prime VP8*-specific mucosal and systemic T cell responses (IFN-γ producing CD4+ and CD8+ T cells), and to induce strong systemic B cell responses (IgA, IgG and serum neutralizing antibodies). A significant reduction in the mean diarrhea duration, fecal virus shedding titers, and significantly lower fecal cumulative consistency scores was observed among vaccinated pigs demonstrating the efficacy of the vaccine against RV infection and diarrhea. Next, we determined the median infectious dose (ID50) and median diarrhea dose (DD50) of the GII.4/2003 Cin-1 variant of HuNoV in Gn pigs to better standardize the pig model for HuNoV vaccine evaluation. Gn pigs were inoculated with 7 different doses of Cin-1 at 33-34 days of age. Pigs were monitored daily from post-inoculation day (PID) 1 to 7, for fecal virus shedding and fecal consistency to evaluate the virus infectiousness and associated diarrhea. The Log10 ID50 and DD50 were determined based on various mathematical models to be between 3.11 to 3.76, and 3.37 to 4.87 RNA copies, respectively. The Beta-Poisson was identified to be the best-fitting statistical model for estimating both the ID50 and DD50 of Cin-1. Determining the ID50 of the challenge virus strain is crucial for identifying the true infectiousness of HuNoVs and for accurate evaluation of protective efficacies in pre-clinical studies of therapeutics, vaccines and other prophylactics using this reliable animal model. The lack of an easily reproducible cell culture model for HuNoV has significantly delayed the development of effective vaccines. There is still no HuNoV vaccine available. Currently, the vaccine development efforts are mostly based on genetically engineered virus-like particles (VLPs) comprised of the major HuNoV capsid protein VP1. We tested the immunogenicity of a novel tetravalent VLP vaccine containing 4 major HuNoV genotypes (GI.1, GII.3, GII.4 and GII.17) using Gn pigs and evaluated its protective efficacy when challenged with GII.4 Cin-1 HuNoV. Three doses of the VLP vaccine with Al(OH)3 adjuvant administered to Gn pigs intramuscularly (IM), induced high levels of VLP-specific serum IgA and IgG antibody and hemagglutination inhibition antibody responses in the vaccinated pigs. VLP-specific IFN-γ producing CD4+ and CD8+ T cells were also elevated among vaccinated pigs at post-challenge day (PCD) 7 in the spleen and blood, but not in the ileum. However, the vaccinated pigs were not protected from infection and diarrhea when challenged with any one of the three different doses (2 x 105, 8 x 104, and 2 x 104 genome RNA copies) of Cin-1 HuNoV. These results indicated that the IM tetravalent VLP vaccine was highly immunogenic, but the presence of high levels of immune effectors induced by the vaccine were not sufficient for protecting the Gn pigs from Cin-1 challenge. Amino acid (aa) sequence analysis showed that the GII.4 Sydney 2012 strain which was included in the VLP vaccine, had 23 aa substitutions in the major receptor binding domain (P2) compared to the Cin-1, a GII.4 Farmington Hills 2002 strain. Our findings, for the first time, provided in vivo experimental evidence for the total lack of cross-genogroup, cross-genotype and cross-variant protection among HuNoV. This finding has importance implications for HuNoV vaccine development. HuNoV vaccines have to include multiple variants and have to be routinely updated in order to ensure sustained protection among the population. Together these three studies in this dissertation demonstrate the versatility of Gn pigs as a reliable large animal model for studying the pathogenesis and immunity of enteric viruses and the evaluation of immunogenicity and protective efficacy of novel enteric viral vaccines. / Doctor of Philosophy / People of all age groups are susceptible to acute gastroenteritis (AGE), a condition characterized by sudden onset of diarrhea, nausea and abdominal cramps. The two most important viral pathogens responsible for causing AGE are rotavirus (RV) and norovirus (NoV). Gnotobiotic (Gn) pigs have been valuable in helping us understand the mechanism of infection, pathogenesis, immunity and have played a key role in the expediting development of novel vaccines and therapeutics against both of these viruses. Live oral RV vaccines are available but they are not very effective in low income countries where the vaccines are needed the most. Next generation parenteral vaccines are proposed to improve the RV vaccine efficacy. Our first study showed that a nanoparticle-based intramuscular (IM) RV vaccine effectively reduced the duration and severity of human RV infection and diarrhea in Gn pigs. Secondly, we examined in detail the infectivity of HuNoV and identified accurately using different mathematical models on how much virus would be required to infect and cause diarrhea in naïve Gn pigs. This knowledge would greatly help in the accurate assessment of the efficacy of NoV vaccines. Third, we evaluated the immunogenicity and protective efficacy of a tetravalent IM NoV vaccine in Gn pigs. Although the vaccine was highly immunogenic, it did not confer any protection against infection and diarrhea upon challenge with the NoV at different doses. NoVs are so diverse that one year we might be infected with one strain and a few years later, we might be infected again with another strain, even though they belong to the same genotype, and experience the same symptoms. This is because, changes brought about due to mutation in the virus capsid protein allow the viruses to hide from neutralizing antibodies induced by previous infection or vaccination as we have revealed in this study. NoV diversity and lack of cross protection need to be taken into consideration during vaccine development. This thesis shows how Gn pigs can be used to study these components in order to further maximize our ability to understand and combat enteric viral diseases.

O presente trabalho visa desenvolver métodos analíticos que permitam determinar as concentrações de oxitetraciclina por Cromatografia Líquida de Alta Eficiência, no leite, plasma e líquido sinovial, além de analisar as concentrações correspondentes em gado leiteiro em lactação portadoras de doença do casco submetidos aos tratamentos intramuscular e tópico. Adicionalmente, são tecidos comentários sobre a eficácia clínica destes tratamentos. Desta forma, objetivando determinar a depuração de oxitetraciclina no organismo dos animais tratados, a concentração no sítio de ação e a quantidade residual em leite, as amostras biológicas foram colhidas e quantificadas em diferentes tempos pré e pós-administração do fármaco. Os métodos analíticos validados apresentaram linearidade, limite de detecção, quantificação, exatidão, precisão e recuperação adequadas à quantificação do antibiótico nas matrizes estudadas. Através da administração do medicamento por via intramuscular, observou-se resíduos acima dos limites máximos (100ppb) estabelecidos pela legislação brasileira para oxitetraciclina no leite até 120 horas após a última administração do medicamento pelo esquema seriado de doses. Já pela via tópica, não foram observados valores residuais na matriz biológica. Do ponto de vista clínico, o tratamento tópico foi eficiente nos animais tratados, levando a cura das lesões. Com relação ao tratamento intramuscular, não foram observados resultados satisfatórios, pois a maioria das lesões não regrediu após as administrações. / The purpose of the present work is to develop methods which allow the determination of oxytetracycline by High Pressure Liquid Chromatography in milk, serum and synovial fluid, as well as analyze the corresponding concentration in milk cattle with foot lameness subjected to intramuscular and topical administration of the antibiotic. It is also commented the clinical efficacy of these two treatments. Thus, to determine the clearance of oxytetracycline in the body of the treated animals, the concentration on the site of action, and the antibiotic residue in milk, biological samples have been collected and analyzed for the oxytetracycline content at different times before and after the drug administrations. The validated analytical methods showed suitable linearity, detection and quantification limits, accuracy, precision and recovery, allowing proper quantification of the antibiotic in the studied biological matrices. When administered intramuscular1y, oxytetracycline residues were observed in milk above the maximum limits (100ppb) established by the brazilian legislation up to 120 hour after the last administration of the medicine using multiple doses treatment, whereas on topical use, residues were not observed in this matrix. When analyzing the clinical aspects, topical treatment was very efficient, leading to the healing of the treated animals. In relation to intramuscular treatment, non satisfactory results were observed, as most of lesion did not disappear after the antibiotic administration.

O presente trabalho visa desenvolver métodos analíticos que permitam determinar as concentrações de oxitetraciclina por Cromatografia Líquida de Alta Eficiência, no leite, plasma e líquido sinovial, além de analisar as concentrações correspondentes em gado leiteiro em lactação portadoras de doença do casco submetidos aos tratamentos intramuscular e tópico. Adicionalmente, são tecidos comentários sobre a eficácia clínica destes tratamentos. Desta forma, objetivando determinar a depuração de oxitetraciclina no organismo dos animais tratados, a concentração no sítio de ação e a quantidade residual em leite, as amostras biológicas foram colhidas e quantificadas em diferentes tempos pré e pós-administração do fármaco. Os métodos analíticos validados apresentaram linearidade, limite de detecção, quantificação, exatidão, precisão e recuperação adequadas à quantificação do antibiótico nas matrizes estudadas. Através da administração do medicamento por via intramuscular, observou-se resíduos acima dos limites máximos (100ppb) estabelecidos pela legislação brasileira para oxitetraciclina no leite até 120 horas após a última administração do medicamento pelo esquema seriado de doses. Já pela via tópica, não foram observados valores residuais na matriz biológica. Do ponto de vista clínico, o tratamento tópico foi eficiente nos animais tratados, levando a cura das lesões. Com relação ao tratamento intramuscular, não foram observados resultados satisfatórios, pois a maioria das lesões não regrediu após as administrações. / The purpose of the present work is to develop methods which allow the determination of oxytetracycline by High Pressure Liquid Chromatography in milk, serum and synovial fluid, as well as analyze the corresponding concentration in milk cattle with foot lameness subjected to intramuscular and topical administration of the antibiotic. It is also commented the clinical efficacy of these two treatments. Thus, to determine the clearance of oxytetracycline in the body of the treated animals, the concentration on the site of action, and the antibiotic residue in milk, biological samples have been collected and analyzed for the oxytetracycline content at different times before and after the drug administrations. The validated analytical methods showed suitable linearity, detection and quantification limits, accuracy, precision and recovery, allowing proper quantification of the antibiotic in the studied biological matrices. When administered intramuscular1y, oxytetracycline residues were observed in milk above the maximum limits (100ppb) established by the brazilian legislation up to 120 hour after the last administration of the medicine using multiple doses treatment, whereas on topical use, residues were not observed in this matrix. When analyzing the clinical aspects, topical treatment was very efficient, leading to the healing of the treated animals. In relation to intramuscular treatment, non satisfactory results were observed, as most of lesion did not disappear after the antibiotic administration.

All trunk muscles are important contributors to spine stability. However, the deepest abdominal muscle, transversus abdominis (TrA), with its characteristically horizontal fibre orientation seems to serve a unique function in trunk motor control. The main mechanical role of TrA is believed to be to contribute to vertebral alignment during imposed moments on the trunk, executed mainly via either regulating the pressure level within the abdominal cavity and/or transmit forces to the spine via the thoracolumbar fascia. However, the complete function of TrA and what factors affect its activation are still not fully understood. The purpose of the present thesis was to investigate the role of TrA in trunk motor control, specifically in relation to the presence or absence of postural demand on the trunk. The timing and magnitude of TrA activation were investigated, in relation to other trunk muscles, with intramuscular fine-wire electrodes in different loading situations and body positions with varying postural demand. In a side-lying position, with no postural demand of keeping the trunk upright, the activation of TrA was delayed relative the superficial abdominal muscles compared to previous experiments performed in a standing position. The timing and magnitude of activation of TrA did not depend upon the direction of perturbation. In the standing position, different static arm positions revealed that the activation of TrA co-varied with variations in the degree of postural demand on the trunk and also the imposed moments, regardless of moment direction. Finally, a study on rapid arm flexion movements confirmed that TrA is part of the pre-programmed anticipatory response in advance of known perturbations. The activation magnitude of TrA was the same regardless if the arm movement induced flexion or extension  moments on the trunk. In conclusion, the activation of TrA is associated with the upright postural demand on the trunk and with balancing imposed moments acting on the spine, regardless their direction. The findings are in support of the beliefs that TrA act as a general, direction non specific, stabilizer of the lumbar spine.

Intramyocellular lipid (IMCL), an ectopic fat depot found within skeletal muscle fibers, is highly associated with obesity and strongly correlated with insulin resistance. IMCL accumulation in sedentary individuals may contribute to insulin resistance by interfering with insulin signaling in skeletal muscle, leading to inadequate glucose uptake by the cell. Lipid peroxidation is also associated with both obesity and insulin resistance, and with IMCL, but a relationship has yet to be established among all of these variables. The purpose of this project is to study for the first time the relationships among lipid peroxidation, IMCL content, and glucose uptake in skeletal muscle. Nine insulin-sensitive adults (IS), 13 insulin-resistant adults (IR), 10 diabetic (DB) and 8 subjects pre- and post- 12-week intervention with insulin-sensitizing thiazolinedione (TZD) were assessed for soleus IMCL with nuclear magnetic resonance, insulin sensitivity by both hyperinsulinemic-euglycemic clamp (GDR) and homeostasis model assessment index (HOMA1), and anthropometrics, including body mass index (BMI), percent fat by DEXA scan, and waist circumference. Vastus lateralis biopsies of all subjects were homogenized and analyzed by immunoblotting for post-translational protein modifications occurring from lipid-peroxidation (HNE). GDR and HOMA were significantly different among IS, IR, and DB groups, as expected, as were waist circumference and BMI. IMCL was significantly higher in DB than in IS and IR. HNE was also higher in DB than in IS, although it did not differ from IR. HNE was significantly correlated to GDR, HOMA1, and BMI, but not to IMCL, WAIST, or percent fat measures. IMCL showed a strong, negative correlation with GDR and was the primary, independent predictor of GDR in stepwise multiple regression. HNE was the primary, independent predictor of HOMA in stepwise multiple regression. Paired t-tests revealed improvements in insulin sensitivity measures after 12 weeks of TZD intervention, but no significant differences were observed in IMCL or HNE after intervention. These data show that skeletal muscle HNE and IMCL are both determinants of insulin resistance in obese, sedentary adults. HNE and IMCL are not related and therefore impact insulin resistance independently. These results reveal, for the first time, a negative relationship between skeletal muscle HNE and insulin sensitivity in sedentary individuals and underscore the importance of lipid peroxidation in insulin resistance.