A fisioterapia motora vem sendo empregada como terapia de suporte para as distrofias musculares, porém, seu efeito no músculo distrófico e na função motora global precisa ser melhor compreendida para direcionar os tratamentos. Esta pesquisa objetiva elucidar o papel da fisioterapia motora na deposição de colágeno muscular, bem como em alguns parâmetros cinemáticos e dinâmicos da marcha do modelo Golden Retriever Muscular Dystrophy (GRMD). Fragmentos do músculo bíceps femoralis foram coletados por biópsia de cinco animais GRMD de mesma idade para análises por microscopia de luz e imuno-histoquímica. A marcha dos animais foi registrada por câmeras de vídeo e as Forças de Reação do Solo (FRS) nos sentidos vertical (Fy), craniocaudal (Fx) e mediolateral (Fz) coletadas utilizando uma plataforma de força Kistler AG (9287A/100Hz) com os valores normalizados pelo peso corporal. Dois animais (tratados: TD) participaram do protocolo de fisioterapia que consistiu de atividade de marcha com velocidade controlada em área de 288 metros, 3 vezes/semana durante 12 semanas. Os animais controles (CD) mantiveram sua rotina de atividades diárias. A coleta I foi considerada como tempo zero (t0) com n=5 e o tempo após a fisioterapia (t1) como coleta II. As análises estatísticas consideraram p<.01. Foi realizada Imuno-histoquímica anti-colágenos tipo I, III (Calbiochem®) e IV (Bioreagents®). As características histopatológicas foram observadas no t0. Os CD apresentaram fibras hipercontraídas no t1, não observadas nos TD. Os colágenos do tipo I e III foram os mais presentes e aumentados. No t1, feixes espessos de colágeno do tipo I foram observados no endomísio dos TD, comparado ao t0. Os animais GRMD apresentaram velocidade lenta de marcha no t0 (0.64 m.s-1) com diminuição da mesma no t1 para os TD (0.45 m.s-1). No t1, os TD apresentaram diminuição da ADM do quadril (p<.0001), bem como do ombro (p<.05). O joelho e carpo dos animais foram as articulações com maiores ADM durante a marcha. Houve aumento da força vertical (Fy) dos membros torácicos e pélvicos dos TD e CD no t1 comparada ao t0. Os CD mostraram aumento do tempo de suporte dos membros torácicos no t1. A força propulsiva (Fx-) dos animais GRMD estava diminuída no t0, não mostrando sofrer influência da fisioterapia. A força medial (Fz+) do membro torácico dos TD mostrou aumento no t1 quando comparada aos CD p<.0001). Os animais tratados apresentam diminuição da flexibilidade e menor regeneração do tecido muscular em comparação aos animais não tratados. Funcionalmente, a fraqueza muscular dos animais distróficos reflete em uma marcha lenta, com característica de sobrecarga e dificuldade de avançar com o corpo. Além destas características, os TD apresentam menor amplitude de movimento articular proximal quando comparado ao t0. A fisioterapia motora aplicada acelera as alterações morfológicas no músculo distrófico sem interferir na progressão das disfunções de marcha no modelo canino da distrofia muscular. / Physiotherapy has been widely used as support treatment for muscular dystrophies. Its effect on dystrophic muscle and global function should be better understood to guide treatments. This study aims to understand the role of motor physical therapy on muscular collagen deposition and some kinematics and dynamical parameters of gait of the Golden Retriever Muscular Dystrophy (GRMD) model. Five GRMD dogs with the same age had fragments of biceps femoralis collected by biopsy for light microscopy and Immunohistochemistry analysis. Gait of the dogs were video recording for kinematics analysis and Ground Reaction Forces (GRF) in vertical (Fy), craniocaudal (Fx) and mediolateral (Fz) direction were collect using a Force Plate Kistler AG (9287A/100Hz) and normalized for body weight. Two animals (therapy dogs: TD) underwent a protocol which consisted of velocity controlled walking activity in an area of 288 meters total length, 3 times/week per 12 weeks. Control dogs (CD) maintained their daily routine. Zero time (t0) is considered at collect I (n=5) and time after therapy (t1) - collect II. Statistical analysis considered p<.01. Immunohistochemistry anticollagen types I, III (Calbiochem®) and IV (Bioreagents®) were performed. Histopathology features were observed at t0. CD presented hypercontracted fibers that were not observed on TD at t1. Collagen types I and III were the most increased ones. At t1, thicker tracts of collagen type I were observed at the endomysium of TD compared to t0. GRMD dogs presented slow velocity of gait (0.64 m.s-1) at t0 and there were a decrease of this velocity of TD at t1 (0.45 m.s-1). Hip ROM was decrease at t1 (p<.0001), as well as the shoulder ROM (p<.05) for TD. Stifle and Carpal ROM presented the highest active ROM during gait of dystrophic dogs. Fy of thoracic and pelvic limbs at t1 of TD and CD was higher than t0. CD presented increase of support time of thoracic limbs at t1 (49 to 53%). Propulsive force (Fx-) of GRMD dogs were decrease at t0, with no effect of physical therapy. Medial force (Fz+) of TD thoracic limbs were higher at t1 when compared to CD (p<.0001). TD presents less muscular flexibility and regeneration when compared to CD. Functionally, the muscular weakness of dystrophic dogs reflects a gait with slow velocity, overloaded and difficulty to goes forward. Moreover, TD presented lower range of motion of the proximal joints when compared to t0. The applied motor physical therapy accelerates the morphological alterations on dystrophic muscle without stop the gait disorders of the canine model of Duchenne muscular dystrophy.

Made available in DSpace on 2019-03-29T23:21:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-12-15 / It's been recognized, day by day, that the relationships a persons maintains though life have a positive influence in contributing for a better and healthier life condition. The current research used an analysis methodology of social networks to analyze the formal and informal support given to the familiar-caretaker of people suffering from Spinal Muscular Atrophies types I and II. Thirteen mothers were used in this research as being the main Caretakers of their ill children. The research was developed all through the year of 2008, and the data collection was made in the residences of those mothers and in the facilities of the Albert Sabin Children's hospital, in Fortaleza-Ceará. The collection of data was made by the meanings of interviews and the use of a name generator and a relationship qualificator especially adapted for the use of the researcher. The quantitative data were processed by the computing programs UCINET 6.123 and NetDraw 2.38 respectively for the entry and manipulation of the data and for the visualization of the maps of the formal and informal network program. The qualitative data was organized as per the Collective Subject Speech technique. The analyses were made based on the network maps and of the collective speeches made on the subjects of: Do I have difficulties in manipulating him? Do I need someone's help in dealing with the equipment? Does the difficulty increases when I get sick? Is it always complicated to set boundaries? The formal social-network allowed identifying the caretaking families and they reveled the existence of 72 actors, among health professionals, education professionals and others that were connected with 12 institutions. The informal network was composed of 83 actors. A density of 0,0123 was identified, which imply that of 6.806 possibilities of a relation, only 83 were actually done. Considering the type of support received, 77 people were referred as emotional support (an average of 5.92 per informant and standard deviation of 1,84); 52 as suppliers (an average of 4 per informant and standard deviation of 2,12) and 17 as information support (an average of 1,30 per informant and standard deviation of 1,25). It was observed that the management of the care given, even when the Familiar-Caretaker has people to support him, is a reason for great emotional distress. These people, by living in these conditions, developed mechanisms that allowed them to conciliate the caring for the ill person with their own physical and economic conditions. The emotional and social areas were the ones that were most debilitated. It was considered the necessity of an intervention in the studied network, enlarging the connections and the assistance potential of that strategy. Proper Health care, social instrumentalization and psychological support must still be provided, minimizing the risks of rejection by the sick and the health hazards for the caretaker. In conclusion, it's clear the importance of the application of the network analysis, as a tool for the knowledge of the structural aspects and the dynamics of the networks, as is the recognition and the use of the existent social support in the reality of the Familiar-Caretaker of people suffering from Spinal Muscular Atrophy. / Cada vez mais vem sendo reconhecida a influência dos relacionamentos que uma pessoa mantém ao longo de sua vida, contribuindo para a melhoria das condições de vida e a prevenção do adoecimento. Na presente pesquisa utilizou-se a metodologia de Análise de Redes Sociais para analisar a rede formal e informal de apoio ao Familiar Cuidador de pessoa com Atrofia Muscular Espinhal tipos I e II. Foram utilizadas como informantes 13 mães, as cuidadoras principais de seus filhos doentes. A pesquisa foi desenvolvida durante o ano de 2008, sendo a coleta de dados realizada nas residências dos informantes e nas dependências do Hospital Infantil Albert Sabin, em Fortaleza-Ceará. Para tanto, utilizou-se a entrevista e o instrumento gerador de nomes e qualificador da relação, adaptado para ser aplicado pela pesquisadora. Os dados quantitativos foram processados através dos programas computacionais UCINET 6.123 e NetDraw 2.38, respectivamente para a entrada e manipulação dos dados e para a visualização dos mapas das redes formal e informal. Os dados qualitativos foram organizados com base na técnica do Discurso do Sujeito Coletivo. As análises se deram em função dos mapas de rede e dos discursos coletivos suscitados pelas Idéias Centrais: eu sinto dificuldade pra manusear ele; preciso de uma pessoa para ajudar e lidar com os aparelhos, pois a dificuldade maior é quando eu adoeço; e é sempre muito complicado impor limites. A rede social formal permitiu identificar que os Familiares Cuidadores revelaram a existência de 72 atores, entre profissionais das áreas da saúde, educação e outros, vinculados a 12 instituições. A rede informal total era composta de 83 atores. Identificou-se uma densidade de 0,0123, o que implica dizer que de 6.806 possibilidades de relações, apenas 83 estavam sendo concretizadas. Considerando o tipo de suporte percebido, 77 pessoas foram referidas como suporte emocional (média de 5,92 por informante e desvio padrão de 1,84); 52 como suporte material (média de 4 por informante e desvio padrão de 2,12) e 17 como suporte informativo (média de 1,30 por informante e desvio padrão de 1,25). Constatou-se que o gerenciamento do cuidado, mesmo quando o familiar cuidador pode contar com pessoas que lhe dêem suporte, é motivo de estresse e sobrecarga. Ao vivenciarem essa condição, desenvolveram mecanismos que lhes permitiam conciliar o cuidado com a pessoa doente e as suas condições físicas e econômicas. As dimensões emocional e social eram as mais comprometidas. Considerou-se haver necessidade de intervenção na rede estudada, ampliando as conexões e conseqüente potencial de ajuda dessa estratégia. Ainda devem ser assegurados acompanhamentos em saúde, sociais de instrumentalização e psicológicos de empoderamento, minimizando, com isso, os riscos de rejeição do cuidado e adoecimento do Familiar Cuidador. Conclui-se pela importância da aplicação da Análise de Redes Sociais como ferramenta para conhecimento dos aspectos estruturais e da dinâmica das redes, assim como o reconhecimento e a utilização dos apoios sociais existentes na realidade do Familiar Cuidador de pessoas com Atrofia Muscular Espinhal.

As distrofias musculares constituem um grupo heterogêneo de doenças genéticas, caracterizadas por uma degeneração progressiva e irreversível dos músculos. Modelos murinos distróficos, como o mdx, SJL/J, Largemyd e Lama2dy-2J/J, são ferramentas importantes para o estudo destas doenças. O objetivo deste trabalho consistiu em estabelecer parâmetros de avaliação funcional que visem a sua utilização para elucidar os benefícios clínicos de futuras terapias. Para tanto, foram avaliadas as quatro linhagens distróficas, em diferentes idades, e comparadas a controle normal. Os testes padronizados consistiram em nado forçado, avaliação de resistência/equilíbrio pelos membros anteriores e pelos quatro membros, caminhar em plataforma suspensa, suspensão pela cauda, grip strength e rota rod. Comprovou-se a existência de diferentes padrões de força, resistência, coordenação motora e aprendizagem/memória ao longo do tempo de vida de cada linhagem, o que permitiu traçar parâmetros a serem utilizados em futuras pesquisas de terapia celular e farmacológica. / Muscular dystrophies are a heterogeneous group of genetic diseases characterized by a progressive and irreversible degeneration of the muscles. Dystrophic mouse models, like the mdx, SJL/J, Largemyd and Lama2dy-2J/J, are important tools for studying these diseases. The aim of this study was to establish parameters for functional evaluation aiming its use to elucidate the clinical benefits of future therapies. Thus, we evaluated the four strains of dystrophic mice, at different ages, and compared to normal control. Standardized tests consisted of forced swimming, evaluation of resistance/balance by forelimb and four members, walking on suspended platform, suspension by the tail, grip strength and rota rod. We observed the existence of different patterns of strength, endurance, coordination and learning / memory over the lifetime of each strain, which allowed tracing parameters to be used in future studies of cell and pharmacology therapies.

O principal objetivo deste estudo foi propor uma metodologia para calcular da força de contato patelofemoral in vivo durante uma atividade dinâmica. Para isso, um protocolo foi operacionalizado permitindo a determinação de parâmetros biomecânicos das articulações tibiofemoral e patelofemoral. Especificamente, os parâmetros determinados foram: centro de rotação tibiofemoral, centro de rotação patelofemoral, linha de ação do ligamento patelar, linha de ação do músculo quadríceps, distância perpendicular do ligamento patelar, distância perpendicular do músculo quadríceps, força do ligamento patelar e força do músculo quadríceps. Para a determinação dos parâmetros foram utilizadas imagens radiográficas dinâmicas, obtidas no plano sagital, de um indivíduo executando um exercício de extensão de joelho em cadeia cinética aberta, a uma velocidade de 45o/s, em seis situações distintas: sem carga externa e com caneleiras de 1 a 5kg (implementadas de 1kg em 1kg) aplicadas à tíbia. As imagens radiográficas foram captadas a uma freqüência de amostragem de 50 Hz, utilizando-se um videofluoroscópio de marca Axiom Siemens Iconos R100. As imagens obtidas foram reproduzidas e digitalizadas utilizando uma placa de captura da marca Silicon Graphics 320. Foram desenvolvidas rotinas computacionais utilizando o software MatlabÒ para a análise dos dados. A propagação do erro na determinação da força de contato patelofemoral foi calculada pelo método de Kleine & McClintock. O protocolo desenvolvido com base na videofluoroscopia permite determinar todos parâmetros biomecânicos necessários para o modelamento da articulação patelofemoral. Os resultados sugerem que, em comparação com a lei de Hooke, a utilização da dinâmica inversa como forma de determinação da força de contato patelofemoral é mais apropriada. Isso pode ser confirmado pelos menores níveis de erro apresentados pela dinâmica inversa. Com base no método de Kleine & McClintock, a linha de ação do músculo quadríceps parece ser um parâmetro crítico no cálculo da força de contato patelofemoral. / The primary goal of this study was to propose a method to calculate the patellofemoral contact force in vivo during a dynamic activity. In order to do that, a protocol was operacionalized allowing to determine the biomechanical parameters of the tibiofemoral and patellofemoral joints. Specifically, the parameters determinated were: tibiofemoral rotation center, patellofemoral rotation center, patellar ligament’s action line, quadriceps muscle’s action line, the patellar ligament moment arm, the quadriceps muscle moment arm, patellar ligament’s force and quadriceps muscle force. To determine such parameters were used dynamic radiographycal images, obtained in the sagital plane, from one individual executing an exercise of knee’s extension in open kinetic chain, in a speed of 45º/s, in six distinct situations: without external load and with weights of 1 to 5kg (implemented 1kg to 1kg) applied to the tibia. The radiographic images were captured in a sampling frequency of 50Hz, through a videofluoroscope from Axiom Siemens Iconos R100. The images obtained were reproduced and digitalized using a capture plate Slicon Graphics 320. Computer routines were developed with the software Matlab® to analyze the data. The error propagation on patelofemoral contact force determination was calculated by the method of Kleine & McClintock. The protocol developed based on the videofluoroscopy allow to determine all the biomechanical parameters needed to the modeling of the patelofemoral joint. The results suggest that, in comparison with Hooke’s law, the use of inverse dynamics as a way to determine the patellofemoral contact force is more appropriated. This can be confirmed by lower levels of error presented in the inverse dynamics. Based on the Kleine & McClintock’s method, the action line of the quadriceps muscle seems to be a critical parameter on the calculus of the patelofemoral’s contact force.

Magíster en ciencias médicas y biológicas mención nutrición. / Introducción: La medición de la fuerza de agarre de mano (FAM) a través de la dinamometría presenta creciente y significativa evidencia como método de valoración nutricional. Su uso en la práctica clínica diaria aumenta la posibilidad de detección temprana de un deterioro funcional en individuos que presentan valores antropométricos normales. El objetivo principal de este estudio fue evaluar la fuerza de agarre de mano con dinamometría en población chilena sana de la Región Metropolitana, ajustado según edad y género. Además, se consideraron variables sociodemográficas, antropométricas y del estilo de vida. Métodos: Estudio analítico, observacional de corte transversal. Se midió la FAM con un dinamómetro hidráulico marca Jamar y se establecieron asociaciones con variables antropométricas, sociodemográficas y del estilo de vida mediante análisis de regresión lineal bivariado y multivariado. Resultados: Se incluyeron 535 voluntarios sanos. El 67,7% (n=362) fueron mujeres y el 32,3% (n=173) hombres. La mediana y rango intercuartílico (RIC) de edad fue 57 años (P25 43,0-P75 70,0). La mediana y RIC de FAM en mano dominante (MD) y mano no dominante (MND) fue 28,0 kg (P25 23,0-P75 32,0) y 25,5 kg (P25 21,0-P75 29,3) en mujeres y 45 kg (P25 38,0-P75 50,0) y 40 kg (P25 34,5-P75 45,5) en hombres, respectivamente. Los valores de FAM más altos se presentaron hasta los 39 años; a partir de los 40 años se observó un descenso sostenido en la FAM tanto en hombres como en mujeres. La FAM fue un 37% superior en hombres en comparación con mujeres para todos los rangos etarios (p<0,05). En el análisis bivariado todas las variables estudiadas estuvieron asociadas con FAM tanto para mano dominante como no dominante. En el modelo multivariado sólo se mantuvo asociación entre FAM y: Género (b= 11,66, 95% IC 10,14; 13,18, p<0,05), Edad (b= -0,21, 95%IC -0,24; - 0,18, p<0,05), Talla (b= 0,40, 95%IC 0,11; 0,69, p<0,05), Actividad física nivel bajo (b= - 1,37, 95% IC -2,34; -0,40, p<0,05), Actividad física nivel moderado (b= -1,07, 95% IC-1,70; -0,44, p<0,05). Conclusiones: La FAM fue un 37% superior en hombres en comparación con mujeres para todos los rangos etarios. Por cada año que envejece un individuo disminuye su FAM en 300 g en el caso de la mano dominante y en 290 g en el caso de la mano no dominante. Se encontró una asociación significativa con la estatura y el nivel de actividad física. No se encontró una relación significativa entre la FAM y el NSE. El tabaquismo y las variables antropométricas estudiadas no afectaron la FAM. / Introduction: Handgrip strength (HGS) measured by dynamometry presents significant evidence as a nutritional assessment method. Its use in daily clinical practice increases the possibility of early detection of functional impairment in individuals with normal anthropometric values. The main objective of this study was to evaluate HGS in healthy chilean population of the Metropolitan Region, adjusted for age and gender. In addition, sociodemographic, anthropometric and lifestyle variables were considered. Methods: Analytical, observational cross-sectional study. The HGS was measured using the Jamar hydraulic dynamometer. Associations were established with anthropometric, sociodemographic and lifestyle variables through bivariate and multivariate linear regression analysis. Results: 535 healthy volunteers were included. 67.7% (n=362) were women and 32.3% (n=173) men. The median and interquartile range (IQR) of age was 57 years (P25 43.0-P75 70.0). The median and IQR of HGS in dominant hand (DH) and non-dominant hand (NH) was 28.0 kg (P25 23.0-P75 32.0) and 25.5 kg (P25 21.0-P75 29.3) in women and 45 kg (P25 38.0-P75 50.0) and 40 kg (P25 34.5-P75 45.5) in men, respectively. The highest grip strengths values were presented up to 39 years; after 40 years, there was a sustained decrease in HGS in both men and women. The HGS was 37% higher in men compared to women for all age range (p <0.05). In the bivariate analysis all the variables studied were associated with HGS for both dominant and non-dominant hand. In the multivariate model association was maintained between HGS and: Gender (b=11.66, 95% CI 10.14, 13.18, p <0.05), Age (b=- 0.21, 95% CI -0.24; -0.18, p <0.05), height (b = 0.40, 95% CI 0.11, 0.69, p <0.05), low level physical activity (b = -1.37, 95% CI -2.34, -0.40, p <0.05), moderate level physical activity (b = -1.07, 95% CI-1.70, -0.44, p <0.05). Conclusions: The HGS was 37% higher in men compared to women for all age range. For each year that age increases, HGS decreases by 300 g in the dominant hand and by 290 g in the case of the non-dominant hand. A significant association was found with height and low level physical activity. No significant relationship was found between HGS and the socioeconomic level. Smoking and the rest of the anthropometric variables studied did not affect HGS.

Disuse of a limb has been repeatedly demonstrated to cause pronounced atrophy of skeletal muscle. In animals and humans, disuse of a leg due to immobilization can cause pronounced catabolism of many skeletal muscle proteins. Strength, V02 max, oxidative enzyme activities, protein synthesis, and muscle weight are all diminished due to chronic limb immobilization.Testosterone is classified as an anabolic steroid which has the effect of increasing protein synthesis in many tissues. Recently, testosterone has been shown to have a definite anti-catabolic effect on skeletal muacle by competing with glucocorticoids for binding proteins within the muscle cell. This reduces the effect of the circulating catabolic hormones. By slowing protein breakdown and increasing protein synthesis in the skeletal muscle of an immobilized limb, testosterone could effectively delay the rapid atrophy so often seen.To examine the effects of testosterone on skeletal muscle atrophy during limb immobilization, forty albino, male rats were randomly divided into four groups of ten. Group I served as the non-immobilized control and received daily placebo injections of sesame oil. The rats in group II were castrated and their hindlimbs were immobilized using a plaster cast. The animals in this group also received daily injections of sesame oil. The group III rats were also castrated and casted, but they received a daily injection of 5 mg testosterone propionate. The animals in group IV were not castrated but were casted.These rats also received a daily injection of testosterone. The duration of treatment was two weeks for each rat. Body weights were measured before and after treatment. The gastrocnemius, quadriceps, soleus, and cardiac muscles were weighed after treatment. Oxygen consumption capacity (Q02), citrate synthase activity, total protein, and percentage of water were also measured in the gastrocnemius, quadriceps, and cardiac tissues.The results of this study demonstrate that hindlimb immobilization not only causes severe atrophy in those muscles immobilized, but has an overal catabolic effect on the animal. Along with the effects on muscle and body size, the immobilization also significantly reduced the aerobic capacity of affected muscle groups and cardiac tissue. The study also gave evidence that testosterone, or the lack of it, can affect the rate of muscle atrophy. The greatest reduction in body weight, muscle size, heart size, and QO2 were seen in the castrated group which only received a placebo injection of sesame oil. The anti-catabolic effect of testosterone was evedent in groups III and IV.

Introducción: las condiciones de intubación con rocuronio varían de acuerdo a la dosis administrada, pudiendo lograrse proporciones diferentes de condiciones adecuadas o inadecuadas. Se investigaron los efectos de 1 DE95, 2 DE95 y >3DE95. Objetivos: comparar las condiciones de intubación con diferentes dosis de rocuronio en pacientes programados para cirugía electiva. Material y métodos: se empleó una escala de valoración de la relajación muscular, la escala de Domaoal para poder comparar los resultados. Los operadores completaron una ficha de reporte sobre las condiciones de intubación para poder hacer las comparaciones. Resultados: la comparación entre los valores en la escala de Domaoal, clasificación de Cormack-Lehane, escala de Adnet y tiempo de intubación de los pacientes tratados con diferentes dosis de rocuronio sometidos a intubación endotraqueal demostró la existencia de diferencia significativa. Conclusiones: con el empleo de rocuronio se logra condiciones de intubaciones buenas y excelentes en pacientes medicados con dosis 2DE95 o más. El empleo de 1 DE95 está asociado a un porcentaje significativamente incrementado de condiciones de intubación inadecuadas.

The Effects of a glucocorticoid-antagonist on IGF1-stimulated glucose uptake in skeletal muscle of hindlimb suspended rats. Barnes B.R., T.C. Selix, D.C. Wright, and B.W. Craig. Ball State University, Muncie, IN.The purpose of this investigation was to determine the effects of a glucocorticoid-antagonist (RU486) on insulin-like-growth-factor-1 (IGF1)stimulated glucose transport following two weeks of hindlimb suspension (HS) on 100 gm male rats. After two weeks of HS and/or oral RU486 administration the animals were anesthetized, and the soleus (SOL) and extensor digitorum longus (EDL) muscles isolated and clamped at their resting length. Following an incubation series to prepare the muscle, the muscle was incubated in radioactive 3-O-methylglucose for 10 min. in the presence/absence of 75 ng/ml of IGF1, digested with 0.5 NaOH, and the amount of glucose transported measured. Two weeks of RU486 treatment significantly (P:5 0.05) elevated IGF1-stimulated glucose transport of SOL (0.576 ± 0.071 vs 1.405 ± 0.172), whereas the EDL was unaffected (2.728 0.258 vs 2.613 ± 0.182). The removal of glucocorticoids via RU486 administration significantly increased glucose uptake in HS exposed soleus muscles. The EDL was not affected by RU486 treatment. / School of Physical Education

The human androgen receptor (hAR) is a ligand-activated, DNA-binding nuclear transcription factor. Mutations in the hAR result in varying degrees of androgen insensitivity (AI); they may play a predisposing or pathogenetic role in both prostate and breast cancer. Expansion of the hAR's N-terminal polymorphic Glutamine (Gln) repeat causes a late-onset progressive motoneuronopathy which is associated with mild androgen insensitivity: spinal and bulbar muscular atrophy (SBMA). SBMA belongs to a group of translated CAG trinucleotide repeat expansion neuronopathies that includes Huntington disease, dentatorubral-pallidoluysian atrophy and five distinct spinocerebellar ataxias. The fact that this group of disorders is caused by polyGln expansions in totally unrelated proteins, is one of the main reasons for postulating that a common gain-of-function mechanism must underlie their communal pathogenesis. This common pathogenetic mechanism is postulated to occur via aberrant protein interactions. / I undertook a search for hAR-interacting proteins using a yeast two-hybrid system. A human testes cDNA library was screened several times with two forms of an N-terminal fragment of the hAR: a normal (20 Gin) hAR and an expanded (50 Gin) hAR. A few candidate hAR-interacting proteins were isolated during the library screenings and I tested them for physiological relevance. / A second aspect of my project included the analysis of an aberrant 75-kD protein fragment generated in COS-1 cells transfected with a polyCAG-expanded (n = 44) hAR cDNA. Recent work in Huntington disease and spinocerebellar ataxia type 3 shows the accumulation of insoluble protein aggregates primarily in the nucleus of certain brain cells (Davies et al., 1997; Scherzinger et al., 1997; Paulson et al., 1997). I confirmed the presence of the aberrant hAR-fragment in the nucleus through western analysis of protein samples extracted from the nucleus.

O-mannosylation is a specific form of glycosylation, a post-translational protein modification with O-linked mannose attached to serine or threonine residues. O-mannosylation is implicated in crucial biological processes such as neuronal and muscle development, cell adhesion and cell migration. Two O-mannosyltransferase genes have been described in mammalian genomes so far, POMT1 and POMT2. Disruptions of O-mannosylation result in congenital muscular disorders in humans. The most severe, the Walker-Warburg Syndrome is associated with mutations in POMT1 and POMT2. Just like vertebrates, Drosophila has two O-mannosyltrasferase genes, DmPOMT1 (rt) and DmPOMT2 (tw), which share significant similarities with their mammalian counterparts. Mutations in both DmPOMT1 and DmPOMT2 cause the "rotated abdomen" phenotype, a clockwise rotation of abdominal segments in adult flies. In my dissertation, I analyzed the expression patterns of rt and tw during development. Both genes have similar essentially overlapping expression patterns. Immunostaining revealed that RT and TW proteins are co-localized in the ER compartment. The analysis of double mutants revealed a mutual epistatic relationship between rt and tw, which could be evidence for RT and TW functioning in the same molecular complex. Also, I studied temporal and spatial requirements of tw during development. I found a broad "developmental window competent to fully rescue the abdomen rotation in adult flies." The spatial studies of tw requirements demonstrated that tw expression is pattern-dependent and the function of tw is cell-autonomous or it has a very short-range effect. The analysis of rescue results with different drivers suggested that the tw requirement is not strictly limited to larval epidermis or muscles alone, but required a contribution from epidermal and muscle cells with a possible involvement of CNS. I have shown that Drosophila Dystroglycan is modified with mannose in the presence of RT-TW enzymatic complex in vivo and in vitro. The co-expression of RT and TW is required to generate high-molecular-mass bands of DG. The lectin staining revealed differences in glycan compositions of DG purified from different genetic backgrounds. Overall, this research work established Drosophila as a model system to study mannosylation, which may shed light on mechanisms of muscular dystrophies in humans.