Muscle strain injuries affect a wide range of physically active people around the world and are reaching epidemic proportions. Despite the variety of treatment options available in rehabilitation, there are no clear guidelines for electrical stimulation that provide effective reproducible results that address the underlying cause of these injuries. For instance, electrotherapy is inefficient at stimulating muscles, because of imprecise parameters and an ability to target particular muscles. The difference between this study and previous research is the precise delivery of electrical stimulation (intramuscular) at two different frequencies (2 Hz and 50 Hz) and comparing it a control group. Objective: To determine the difference on muscle strength and functional status between three treatments modalities for sub acute and chronic hamstring strains. Design: A randomized experimental design was used to compare the effects of low (2 Hz), high (50 Hz) and no-electrical (control) intramuscular stimulation on muscle strength and mental and functional status (AMSMC HEALTH STATUS INDEX). Each group consisted of 18 subjects. Main Outcome: The difference in treatment modalities was evaluated by comparing the muscle strength test (Biodex Dynamometer) results and the AMSMC HEALTH STATUS INDEX results in pretest and post-test conditions. Results: The AMSMC HEALTH STATUS INDEX, but not muscle strength test (Biodex), changed significantly after 2-Hz electrical intramuscular stimulation (pre-test µ = 66.56, Std= 11.92, post-test µ= 92.89, Std= 6.25), whereas no statistically significant changes in health status index and muscle strength test occurred with 50-Hz (pre-test = 69.22, Std= 11.31, post-test µ= 70.22, Std= 12.27)) and no-electrical stimulation groups (pre-test µ= 69.11, post-test µ= 73.39, Std= 13.18).

Muscle strain injuries affect a wide range of physically active people around the world and are reaching epidemic proportions. Despite the variety of treatment options available in rehabilitation, there are no clear guidelines for electrical stimulation that provide effective reproducible results that address the underlying cause of these injuries. For instance, electrotherapy is inefficient at stimulating muscles, because of imprecise parameters and an ability to target particular muscles. The difference between this study and previous research is the precise delivery of electrical stimulation (intramuscular) at two different frequencies (2 Hz and 50 Hz) and comparing it a control group. Objective: To determine the difference on muscle strength and functional status between three treatments modalities for sub acute and chronic hamstring strains. Design: A randomized experimental design was used to compare the effects of low (2 Hz), high (50 Hz) and no-electrical (control) intramuscular stimulation on muscle strength and mental and functional status (AMSMC HEALTH STATUS INDEX). Each group consisted of 18 subjects. Main Outcome: The difference in treatment modalities was evaluated by comparing the muscle strength test (Biodex Dynamometer) results and the AMSMC HEALTH STATUS INDEX results in pretest and post-test conditions. Results: The AMSMC HEALTH STATUS INDEX, but not muscle strength test (Biodex), changed significantly after 2-Hz electrical intramuscular stimulation (pre-test µ = 66.56, Std= 11.92, post-test µ= 92.89, Std= 6.25), whereas no statistically significant changes in health status index and muscle strength test occurred with 50-Hz (pre-test = 69.22, Std= 11.31, post-test µ= 70.22, Std= 12.27)) and no-electrical stimulation groups (pre-test µ= 69.11, post-test µ= 73.39, Std= 13.18).

Muscle strain injuries affect a wide range of physically active people around the world and are reaching epidemic proportions. Despite the variety of treatment options available in rehabilitation, there are no clear guidelines for electrical stimulation that provide effective reproducible results that address the underlying cause of these injuries. For instance, electrotherapy is inefficient at stimulating muscles, because of imprecise parameters and an ability to target particular muscles. The difference between this study and previous research is the precise delivery of electrical stimulation (intramuscular) at two different frequencies (2 Hz and 50 Hz) and comparing it a control group. Objective: To determine the difference on muscle strength and functional status between three treatments modalities for sub acute and chronic hamstring strains. Design: A randomized experimental design was used to compare the effects of low (2 Hz), high (50 Hz) and no-electrical (control) intramuscular stimulation on muscle strength and mental and functional status (AMSMC HEALTH STATUS INDEX). Each group consisted of 18 subjects. Main Outcome: The difference in treatment modalities was evaluated by comparing the muscle strength test (Biodex Dynamometer) results and the AMSMC HEALTH STATUS INDEX results in pretest and post-test conditions. Results: The AMSMC HEALTH STATUS INDEX, but not muscle strength test (Biodex), changed significantly after 2-Hz electrical intramuscular stimulation (pre-test µ = 66.56, Std= 11.92, post-test µ= 92.89, Std= 6.25), whereas no statistically significant changes in health status index and muscle strength test occurred with 50-Hz (pre-test = 69.22, Std= 11.31, post-test µ= 70.22, Std= 12.27)) and no-electrical stimulation groups (pre-test µ= 69.11, post-test µ= 73.39, Std= 13.18). / Education, Faculty of / Kinesiology, School of / Graduate

An ideal dexmedetomidine protocol has yet to be determined for standing sedation in horses. It was hypothesized that an intravenous (IV) bolus followed by continuous rate infusion (CRI) dexmedetomidine would have a quicker increase in plasma concentrations compared to repeated intramuscular (IM) injections. In a cross-over design, eight adult, female horses were randomly placed in two groups: the CRI group (IV bolus dexmedetomidine at 0.005 mg/kg followed by a CRI at 0.01 mg/kg/hr for 15 minutes then 0.005 mg/kg/hr for 60 minutes) and the IM group (dexmedetomidine at 0.01 mg/kg, followed by 0.005 mg/kg in 30-minute intervals for 60 minutes). Analgesia was evaluated using a mechanical pressure threshold device. Intravenous dexmedetomidine produced faster onset of sedation and increased pressure threshold compared to IM administration. Individual horses had a large variability in dexmedetomidine plasma concentrations between CRI and IM administration.

No description available.

STUDY DESIGN: Randomized crossover experiment. OBJECTIVE: To determine whether the Rich-Mar AutoSound™ would be as effective as traditional ultrasound at increasing the temperature of the triceps surae muscle during a 10-min, 1 MHz, 1.0 W/cm2 ultrasound treatment. BACKGROUND: The AutoSound™ is a hands-free ultrasound device that is strapped on the body and left for the duration of the ultrasound treatment. It requires no clinician during the actual ultrasound treatment, thus freeing the clinician to perform other tasks and reducing clinician error during treatments. METHODS: 16 healthy subjects (6 males, 10 females, age = 22 ± 1.6 yrs, height = 173.2 ± 8.4 cm, weight = 72.5 ± 11.3 kg, triceps surae subcutaneous fat thickness = 0.85 ± 0.37 cm) received a 10-min, 1 MHz, 1.0 W/cm2 ultrasound treatment over their left triceps surae muscle with both the AutoSound™ and traditional ultrasound (via the TheraHammer™) with 24 hours between treatments. Temperatures were measured every 30 seconds during the ultrasound treatments by way of a thermistor, approximately 2.25 cm deep in the triceps surae. RESULTS: The AutoSound™ was not effective at increasing the temperature of the triceps surae muscle, as temperature decreased 0.16°C during treatment (p = 0.334). On average, the AutoSound™ caused intramuscular temperature to decrease at a rate of 0.016 ± 0.001°C per min. Traditional ultrasound performed using the TheraHammer™ had a total temperature increase of 0.41°C. Rate of temperature increase during traditional ultrasound was 0.025 ± 0.003°C per min (p < 0.0001). CONCLUSION: The AutoSound™ is not as effective at increasing muscle temperature as traditional ultrasound during a 10-min, 1 MHz, 1.0 W/cm2 treatment. However, neither the AutoSound™ nor traditional ultrasound was very effective at increasing the temperature of the triceps surae muscle during the treatment time.

Pasture feeding depresses adipose tissue development in beef cattle whereas grain feeding, enhances adipogenesis. Therefore, we hypothesized that specific fatty acids would differentially affect lipogenesis in explants of bovine subcutaneous (SC) and intramuscular (IM) adipose tissues. Angus steers were harvested at 12, 14, and 16 mo of age, and IM and SC adipose tissue explants from the 8-11th thoracic rib region were dissected and cultured in media. Media contained no supplemental fatty acids or 40 microM of five fatty acids, stearic acid (18:0), oleic acid (18:1 n-9), trans-11 vaccenic acid (18:1 trans-11), conjugated linoleic acid (CLA, 18:2 trans-10, cis-12), or alpha-linolenic acid (18:3 n-3). After 48 h of culture, lipogenesis using [U-14C]glucose and [1-14C]acetate was measured. Lipogenesis from glucose decreased between 12 and 16 mo of age in SC adipose tissue (from 8.9 to 4.0 nmol per 2 h per 100 mg; P = 0.001) and IM adipose tissue (from 4.4 to 2.7 nmol per 2 h 100 mg ; P = 0.08). Lipogenesis from acetate did not change over time in SC adipose (approximately 56 nmol per 2 h per 100 mg; P = 0.23), but increased over time in IM adipose tissue (from from 11.3 to 17.1 nmol per 2 h 100 mg; P = 0.02). Oleic acid increased lipid synthesis from glucose 125 percent (P = 0.04) in IM adipose tissue, whereas stearic acid and trans-vaccenic acid increased lipogenesis from glucose in SC adipose tissue by approximately 50 percent (P = 0.04). In SC adipose tissue only, trans-vaccenic and increased, lipogenesis from glucose (P < 0.02). Lipogenesis from acetate was depressed by CLA nearly 50 percent in SC adipose tissue. PPARγ gene expression increased between 14 and 16 mo of age in control IM and SC adipocytes. The increase in activity was also observed in AMPK gene expression. C/EBPβ and SCD gene expression did not increase in control samples until 16 mo of age. SC adipose tissue responded to stearic acid by increased GPR43 and AMPK gene expression at 12 mo of age. We conclude that fatty acids differentially affect lipid synthesis in IM and SC adipose tissues, which may account for the effects of pasture and grain feeding on adiposity.

A divergent selection experiment on intramuscular fat (IMF) content was performed in rabbits during eight generations. Selection criterion was the averaged phenotypic value of IMF measured in Longissimus dorsi (LD) muscle at 9 wk of age in two full-sibs of the candidate. The aim of this Thesis is to evaluate the direct response to selection for IMF and the correlated responses in other meat and carcass quality traits. Divergent selection for IMF was successful. Direct response to selection in the eight generation was 2.4 standard deviations (SD) of the trait, which represents a genetic progress of 5% of the mean per generation. Genetic trends were symmetrical for both lines. Correlated responses to selection were measured from fifth to eighth generations. Fatty acid composition of LD was affected by selection for IMF. High-IMF line showed greater monounsaturated (MUFA) but lower polyunsaturated (PUFA) fatty acids percentages, and their individual fatty acid percentages showed similar correlated responses, except for C18:3n-3 that was greater in the high-IMF line. We did not find differences between lines for saturated fatty acid (SFA) percentage, but C14:0 and C16:0 percentages were greater in the high-IMF line, and C18:0 was greater in the low-IMF line. A positive correlated response to selection for IMF was observed in the IMF content and fatty acid composition of other muscles with diverse oxidative pattern (Biceps femoris, Supraspinatus and Semimembranosus proprius). Protein content of LD that was greater in the high-IMF line, whereas we did not observed differences between lines in colour and pH meat quality traits. Instrumental firmness was 9.9% greater in the low-IMF line than in the high-IMF line, whereas we did not find differences between lines in other instrumental texture parameters and cooking loss. No effect of selection for IMF was observed in any sensory attribute. Regarding carcass quality traits, a positive correlated response to selection for IMF was observed in carcass fat depots, whereas we did not find differences between lines in other traits. Genetic parameters for IMF and some of the meat and carcass quality traits cited above were estimated and corrobated with the phenotypic responses to selection observed. In this Thesis, we also studied the lipid metabolism of the divergent lines. High-IMF line showed greater glucose-6-phosphate dehydrogenase (G6PDH), malic enzyme (EM) and fatty acid synthase (FAS) lipogenic activities in glycolytic LD muscle than low-IMF line, and greater G6PDH and FAS activities in the oxidative Semimembranosus proprius muscle and perirenal fat depot. However, differences between lines were observed only at 13 wk of age and not at 9 wk. Catabolic activities in muscle involved in the lipid metabolism did not explain the differences between lines for IMF. Liver size, which is the main lipogenic tissue in growing rabbits, was greater in the high-IMF line and showed greater G6PDH and EM activities than low-IMF line at 9 wk, although differences for EM were not relevant. / Se ha realizado un experimento de selección divergente por grasa intramuscular (GIM) en conejo durante ocho generaciones. El criterio de selección fue el promedio del valor fenotípico de GIM medido en el músculo Longissimus dorsi (LD) a las 9 semanas de edad en dos hermanos completos del candidato a la selección. El objetivo de esta tesis es evaluar la respuesta directa a la selección por GIM y las respuestas correlacionadas en otros carcateres de calidad de la canal y de la carne. La selección divergente por GIM ha tenido éxito. La respuesta directa en la octava generación de selección fue de 2.4 desviaciones típicas (DT) del carácter, lo que representa un progreso genético del 5% de la media en cada generación. Las líneas mostraron tendencias genéticas simétricas. Las respuestas correlacionadas a la selección en caracteres de calidad de la canal y de la carne se evaluaron desde la quinta hasta la octava generación. La composición de ácidos grasos de LD también se vió afectada por la selección. La línea de alta GIM mostró un mayor porcentaje de ácidos grasos moninstaurados (MUFA) y un menos procentaje de poliinsaturados (PUFA) que la línea de baja GIM, y los MUFA y PUFA individuales mostraron respuestas correlacionadas similares a los grupos, excepto el porcentaje de C18:3n-3 que fue mayor en la línea de alta GIM. No encontramos diferencias entre líneas en el porcentaje de ácidos grasos saturados (SFA), aunque los porcentajes de C14:0 y C16:0 fueron mayores en la línea de alta GIM, y el porcentaje de C18:0 fue mayor en la línea de baja GIM. Se observó una respuesta correlacionada positiva en el contenido de GIM y en la composición de ácidos grasos de otros músculos con un patrón oxidativo diferente al LD (Biceps femoris, Supraspinatus y Semimembranosus proprius). El contenido de proteína de LD fue mayor en la línea de alta GIM, mientras que no encontramos diferencias entre líneas en otros caractered de calidad de carne como pH o color. El parámetro de textura instrumental firmeza fue 9.9% en la línea de baja GIM, mientras que no se observaron diferencias entre líneas en otros parámetros de textura instrumental, pérdidas por cocinado, y atributos sensoriales. En cuanto a los caracteres de calidad de carne, se observó una respuesta correlacionada positiva en los depósitos grasos de la canal, mientras que no se observaron diferencias en otros caracteres. Se estimaron los parámetros genéticos de GIM y de otros caracteres de calidad de la carne y de la canal citados anteriormente, y se corroboraron con las respuestas correlacionadas a la selección observadas. En esta tesis también se ha estudiado el metabolismo lipídico de las líneas divergentes. La línea de alta GIM mostró mayor actividad de las enzimas lipogénicas 6-glucosa-fosfato deshidrogenasa (G6PDH), enzima málico (EM) y ácido graso sintasa (FAS) en el músculo glicolítico LD respecto de la línea de baja GIM, y mayor actividad de las enzimas G6PDH y FAS en el músculo oxidativo Semimembranosus proprius y en el depósito de grasa perirrenal. Sin embargo, estas diferencias solo fueron observadas a las 13 semanas de edad, y no a las 9 semanas. En los músculos, las actividades de las enzimas catabolicas implicadas en el metabolsimo de la grasa no mostraron diferencias entre líneas. El hígado, que es el principal tejido lipogénico en conejos en crecimiento, fué más grande en la línea de alta GIM, y mostró mayor actividad de las enzimas G6PDH y EM que la línea baja, aunque las diferencias en EM no fueron relevantes. / S'ha realitzat un experiment de selecció divergent per greix intramuscular (GIM) en conill durant huit generacions. El criteri de selecció va ser la mitjana del valor fenotípic de GIM mesurat en el múscul Longissimus dorsi (LD) a les 9 setmanes d'edat en dos germans complets del candidat a la selecció. L'objectiu d'esta tesi és avaluar la resposta directa a la selecció per GIM i les respostes correlacionades en altres carcateres de qualitat de la canal i de la carn. La selecció divergent per GIM ha tingut èxit. La resposta directa en la sèptima generació de selecció va ser de 2.4 desviacions típiques (DT) del caràcter, la qual cosa representa un progrés genètic del 5% de la mitjana en cada generació. Les línies van mostrar tendències genètiques simètriques. Les respostes correlacionades a la selecció en caràcters de qualitat de la canal i de la carn es van avaluar des de la quinta fins a l'octava generació. La composició d'àcids grassos de LD també es va veure afectada per la selecció. La línia d'alta GIM va mostrar un major percentatge d'àcids grassos moninstaurados (MUFA) i un menys procentaje de poliinsaturats (PUFA) que la línia de baixa GIM, i els MUFA i PUFA individuals van mostrar respostes correlacionades semblants als grups, excepte el percentatge de C18:3n-3 que va ser major en la línia d'alta GIM. No trobem diferències entre línies en el percentatge d'àcids grassos saturats (SFA), encara que els percentatges de C14:0 i C16:0 van ser majors en la línia d'alta GIM, i el percentatge de C18:0 va ser major en la línia de baixa GIM. Es va observar una resposta correlacionada positiva en el contingut de GIM i en la composició d'àcids grassos d'altres músculs amb un patró oxidatiu diferent del LD (Bíceps femoris, Supraspinatus i Semimembranosus proprius). El contingut de proteïna de LD va ser major en la línia d'alta GIM, mentres que no trobem diferències entre línies en altres caractered de qualitat de carn com pH o color. El paràmetre de textura instrumental fermesa va ser 9.9% en la línia de baixa GIM, mentres que no es van observar diferències entre línies en altres paràmetres de textura instrumental, pèrdues per cuinat, i atributs sensorials. Quant als caràcters de qualitat de carn, es va observar una resposta correlacionada positiva en els depòsits grassos de la canal, mentres que no es van observar diferències en altres caràcters. Es van estimar els paràmetres genètics de GIM i d'altres caràcters de qualitat de la carn i de la canal esmentats anteriorment, i es van corroborar amb les respostes correlacionades a la selecció observades. En esta tesi també s'estudia en metabolisme lipídic de les línies divergents. La línia d'alta GIM va mostrar major activitat dels enzims lipogénics 6-glucosa-fosfato deshidrogenasa (G6PDH), enzim màlic (EM) i àcid gras sintasa (FAS) en el múscul glicolític LD respecte de la línia de baixa GIM, i major activitat dels enzims G6PDH i FAS en el múscul oxidatiu Semimembranosus proprius i en el depòsit de greix perirrenal. No obstant això, estes diferències només van ser observades a les 13 setmanes d'edat, i no a les 9 setmanes. En els músculs, les activitats dels enzims catabòlics implicades en el metabolsimo del greix no van mostrar diferències entre línies. El fetge, que és el principal teixit lipogénic en conills en creixement, va ser més gran en la línia d'alta GIM, i va mostrar major activitat dels enzims G6PDH i EM que la línia de baixa GIM, encara que les diferències en EM no van ser rellevants. / Martínez Álvaro, M. (2017). Selección divergente por contenido en grasa intramuscular conejo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/80696 / TESIS / Premios Extraordinarios de tesis doctorales

This study was a randomized control trial. The purpose of this study was threefold: 1) to determine if intramuscular temperature (IMt) increases in the semitendinosus (ST) are similar to the vastus lateralis (VL) during standard WBV static squatting; 2) to determine if changes in intramuscular temperature of the hamstrings is different from a standard static semi-squat when undergoing WBV in a static stretching position; and 3) to determine if shorter overall durations as is typically used for stretching protocols (i.e. 5 repetitions of 30s each), will result in IMt increases. Twelve subjects (all males), with tight hamstrings completed this study (age 23.5 ± 1.5 years; body mass 76.3 ± 17.7 kg; height 177.8 ± 15.2 cm). Subjects were randomly assigned to treatment order of three groups: semi squat vibration (SQ), vibration with static stretch (VS), and static stretch only (SS). Subjects reported to the lab 3x, each visit separated by one week to receive all treatments. Each treatment day consisted of baseline temperature measurements in the VL and ST and following each of 2 sets (5x60-second for SQ, 5x30-second for VS and SS, with 30 seconds rest in between reps). Post-hoc comparisons revealed that VL temperature increases were significantly greater from baseline than the hamstrings at all three time periods (p<.0001). There were no significant differences found in ST IMt when comparing 5-minutes of total WBV in the VS condition (both sets of 2.5 minute bouts) to 5-minutes of vibration in the SQ condition (p=1.000), or between VS and SS after 5 minutes (p=.9827). Post-hoc comparisons between SS and VS conditions revealed no significant differences after 2.5 minutes (p=1.000), 5 minutes (p=.8812), and 10-minutes post vibration (p=.9844) in ST or VL (p=1.000, p=.0540, and p=.1815 respectively) temperature. The results of our study show that the ST does not exhibit similar increases in IMt as the VL when performing standard semi-squat WBV training. The IMts seen in the static stretch both with and without vibration seem to suggest that factors other than IMt most likely contribute to flexibility changes seen in prior WBV flexibility studies.

Em eucariotos, o DNA é organizado juntamente com histonas em um complexo nucleoproteico conhecido como cromatina, cuja unidade fundamental corresponde aos nucleossomos. A cromatina apresenta-se de duas maneiras: eucromatina, região estruturalmente menos condensada e, portanto, mais facilmente transcrita, e heterocromatina, região muito condensada e transcricionalmente silenciosa. Na forma de eucromatina, o acesso dos fatores de transcrição a regiões de DNA livres de nucleossomos é facilitado, enquanto que na forma de heterocromatina os fatores de transcrição não conseguem acessar o DNA para ativar ou reprimir a expressão gênica inferindo, assim, que o grau de compactação da cromatina interfere na regulação da expressão gênica e que o nucleossomo atua como silenciador gênico. Neste contexto, os objetivos foram identificar, mapear e caracterizar regiões em eucromatina na musculatura esquelética de bovinos da raça Nelore. As análises foram realizadas em relação ao músculo Longissimus dorsi pela técnica Assay for Transposase-Accessible Chromatin (ATAC-Seq), capaz de isolar regiões livres de nucleossomos a partir do mecanismo enzimático de transposição. A fim de otimizar o protocolo dessa metodologia para tecido muscular, foram testadas concentrações de 50 mil, 75 mil e 100 mil núcleos tratados com transposase. Destes, foram encontrados 6.811, 11.121 e 11.473 picos de eucromatina, respectivamente, e 6.212 regiões de cromatina aberta foram coincidentes nas três amostras. A associação entre regiões eucromáticas, expressão gênica e gordura intrasmuscular foi confirmada a partir da análise de sobreposição com transcriptional start sites (TSS), genes expressos em músculo esquelético, genes diferencialmente expressos (GDE) para gordura intramuscular e regiões de expression quantitative trait loci (eQTL) de tecido muscular reforçando, assim, o potencial regulatório das regiões de eucromatina. / In eukaryotes, DNA is organized along with histones in nucleoproteins complexes known as chromatin, which has nucleosomes as their fundamental unit. Chromatin exists in two forms: euchromatin, corresponding to a lightly condensed structure and an easily transcribed region, and heterochromatin, a highly condensed and transcriptionally silent region. In euchromatin form, transcription factors have free access to nucleosome-depleted DNA regions, while in heterochromatin the transcription factors can not access the DNA for activate or repress genic expression, which suggests that the chromatin compaction degree interferes with regulation of gene expression and that nucleosomes act as gene silencer. In this context, the aims of the present project were to identify, map and characterize euchromatin regions in the skeletal musculature of Nellore cattle. Analyzes were performed considering the muscle Longissimus dorsi using Assay for Transposase-Accessible Chromatin technique (ATAC-Seq), which isolates nucleosome-depleted regions throught transposition enzymatic mechanism. Differente transposase-treated nuclei concentrations were tested: 50 thousand, 75 thousand and 100 thousand. From these, 6.811, 11.121, and 11.473 euchromatin peaks were found, respectively, and 6.212 open chromatin regions were coincident among them. The association between euchromatic regions, gene expression and intrasmuscular fat was confirmed from the overlap analysis with transcriptional start sites (TSS), genes expressed in skeletal muscle, differentially expressed genes (GDE) for intramuscular fat and regions of expression quantitative trait loci (eQTL) of muscle tissue, reinforcing the regulatory potential of the euchromatin regions.