El presente trabajo se realizó con el propósito de evaluar el efecto de la transferencia embrionaria ipsilateral y contralateral a la posición del cuerpo lúteo sobre la tasa de preñez en llamas. Se utilizaron 43 llamas hembras receptoras de 4 a 6 años, distribuidas aleatoriamente en 4 grupos de estudio: G1 (n=10): Cuerpo lúteo en ovario derecho y transferencia ipsilateral, G2 (n=10): Cuerpo lúteo en ovario derecho y transferencia contralateral, G3 (n=15): Cuerpo lúteo en ovario izquierdo y transferencia ipsilateral y G4 (n=8): Cuerpo lúteo en ovario izquierdo y transferencia contralateral. Se utilizaron 10 llamas hembras como donadoras de embriones, las cuales fueron sincronizadas con LH (1ml), superovuladas con 1000 UI de eCG y se provocó luteólisis con prostaglandina (1ml), siendo empadradas posteriormente. El día del empadre las llamas receptoras recibieron tratamiento con LH, con el propósito de sincronizarlas con las donadoras. Siete días post empadre se realizó el lavado uterino para la recolección, evaluación y transferencia de los embriones. La transferencia embrionaria a los grupos experimentales se realizó con embriones frescos el mismo día. Los resultados obtenidos señalan una tasa de preñez de 60% (G1) y 75% (G3) en las hembras con transferencia embrionaria ipsilateral derecha e izquierda respectivamente, mientras que en la transferencia contralateral derecha e izquierda fueron 30% (G2) y 25%(G4) respectivamente. Sin embargo, no se registraron diferencias significativas (p>0.05) entre el grupo G1 con los grupos G2, G3 y G4, además G2 no muestra diferencias significativas (p>0.05) con G4. Mientras que se encontró diferencia (p menor 0.05) entre el grupo G3 con los grupos G2 y G4. Estos resultados indicarían una mayor tasa de sobrevivencia embrionaria en llamas al realizar la transferencia en el cuerno ipsilateral a la posición del cuerpo lúteo ubicado en el ovario izquierdo. / The study was carried out with the objective of to evaluate the embryo survival after the embryo transfer to the uterine horn ipsilateral and contralateral to the corpus luteum (CL) in llamas. Fourtythree llamas recipient females, from 4 to 6 years old were randomly assigned in 4 groups: G1 (n=10): CL in right ovary and ipsilateral embryo transfer, G2 (n=10): CL in right ovary and contralateral transfer, G3 (n=15): CL in left ovary and ipsilateral transfer, and G4 (n=8): CL in left ovary and contralateral transfer. Ten llamas were used as embryo donors, they were synchronized with LH (1ml), then superovulated with 1000 UI eCG and induced to luteolysis with PGF2α; after that, all of them were mated. The same day of mating, the recipients were treated with LH, with the purpose of synchronization with donors. Seven days postmating, the uterine horns were flushed to recover, evaluate and transfer the embryos. The nonsurgical embryo transfer was used the same day with fresh embryos. The results of pregnancy rate were 60% (G1) and 75% (G3) in recipient females with ipsilateral embryo transfer right and left respectively. On the other hand, contralateral embryo transfer right and left were 30% (G2) and 25% (G4) respectively. However, the differences did not reach significance (p>0.05) between G1 with G2, G3 and G4. Furthermore, G2 not differ (p>0.05) from G4. Whereas, there is difference (p less 0.05) between G3 with G2 and G4. These results indicate that pregnancy rate is major in llamas when the embryo transfer was to the uterine horn ipsilateral to the CL in the left ovary.

Las artroplastias de las grandes articulaciones de carga, como la cadera y la rodilla, se ha demostrado que son procedimientos altamente exitosos para mejorar la calidad de vida en los pacientes con artrosis avanzada. Actualmente, existe discusión en si una previa artroplastia total de cadera (ATC) supone un factor de riesgo para el resultado funcional de una subsecuente artroplastia total de rodilla (ATR). No hemos encontrado ningún trabajo en la literatura que aclare esta controversia. Objetivo: Evaluar la influencia de una ATC primaria previa bien funcionante sobre el resultado funcional de una subsecuente ATR primaria ipsilateral. Material y Métodos: Estudio retrospectivo de casos y controles de 92 pacientes mayores de 60 años que se sometieron a una ATR primaria unilateral después de una ATC ipsilateral previa (grupo ATC-ATR) versus 92 pacientes que se sometieron solo a ATR (grupo ATR). Como instrumentos de medida para la evaluación clínica se emplearon las escalas Knee Society Score (KSS) para la rodilla y Harris Hip Score (HSS) para la cadera, los cuestionarios Reduced Western Ontario y MacMaster Universities (WOMAC) y el Short-Form 12 (SF-12) para la calidad de vida, y pruebas radiológicas complementarias. Resultados: El seguimiento medio después de la ATR fue de 7,2 años (rango 5-9) en el grupo ATC-ATR. No hubo diferencias significativas entre los grupos en el momento de la ATR. Las ganancias medias en el KSS fueron similares en ambos grupos. En el último seguimiento, no hubo diferencias estadísticamente significativas en las puntuaciones de WOMAC-dolor o SF12-físico, pero las puntuaciones de WOMAC-función (p= 0,003) y SF12-mental (p= 0,018) fueron significativamente mejores en el grupo de la ATR aislada. Tampoco hubo diferencias significativas en la alineación radiológica de la rodilla o en la posición de los componentes. Por causas asépticas, la supervivencia de la ATR a los 8 años en el grupo de ATR fue del 95,8% (IC del 95%: 87,8-100%) y del 96,6% (IC del 95%: 91,8-100%) en el grupo de ATC-ATR (p= 0,577). Conclusión: Una ATC previa, bien funcionante, no influye en el resultado funcional de una subsecuente ATR ipsilateral.

This study was undertaken to identify the landmarks that would provide the most reliable and predictable indicators of the position of the supraorbital, infraorbital, mental and mandibular foramina in human skulls of Hokien, Hylam, Indian and British populations of ranging ages, which would provide clinicians with suitable modifications in technique to accommodate these variations. Measurements were taken using both electronic digital callipers and 3D laser scanning. Electronic digital calliper measurements were made to estimate how far each foramen was from specific anatomical landmarks on the skulls. An apparatus was developed to position the skulls securely so that the measurement points could be accurately identified, then an electronic digital calliper was used to measure the distance between the defined points. In addition, the same skulls were also scanned using a FastSCAN™ Polhemus Scorpion™ handheld laser scanner, and imported into 3D modelling software (FreeForm Modelling Plus™). This 3D software integrates a PHANYOM™ desktop arm and a haptic force feedback device that provides the user with a sense of touch. Accordingly, with the “Ruler” tool, the measurements between various foramina and defined anatomical landmarks were measured. Measurements made by electronic digital calliper were compared statistically with those made using the 3D scanning method, and overall there was good correlation between the two, indicating that 3D scanning could be used as an alternative method. With regard to age changes in the skulls, the ages of the Hokien and Hylam groups were known, having been recorded from death records, but the Indian and British skulls were not of known age. In a preliminary study the known age skulls were used to validate the methods of Miles (1962) and Brothwell (1981) who aged skulls using tooth wear patterns. The decision was taken to use the Brothwell chart for the assessment of age in the Indian and British skulls in the main study. For each of the four population groups, intra-population comparisons of the measurements were made between right and left sides, and between skulls of young and old individuals, also inter-population comparisons between ipsilateral measurements were made. The correlation between the obtuseness of the mandibular angle and the ipsilateral measurement from the mental foramen to the posterior border of the mandible were made on both sides of the skulls of each population group. Non-significant differences were found between the measurements on right and left sides for the skulls of all populations. There were significant differences between some ipsilateral measurements but although there were statistically significant, they were not considered to be clinically significant. There were no significant differences between ipsilateral measurements with increasing age of the skulls. Also there were weak correlations between the obtuseness of the mandibular angle and the ipsilateral measurement from the mental foramen to the posterior border of the mandible on both sides of the skulls of each population group. There were good statistically agreements between the electronic digital calliper and 3D laser scanning measurements in all groups and the two methods may be used interchangeably. However 3D scanning is a digital process and therefore the scans could be accessed remotely, either across the internet or by CD.

Rhythmic arm cycling is known to suppress the Hoffmann (H-) reflex in the soleus muscles of stationary legs; however, it is still unclear if this suppression is modulated by the phase of movement in the cycle path. In the present study we investigated phase-dependent modulation of the Sol H-reflex induced by rhythmic arm cycling. Modulation of the Soleus H-reflex was examined at 12 phases of the cycle path in 4 conditions; static arm positioning, as well as 3 arm cycling conditions, bilateral, ipsilateral and contralateral. H-reflexes were evoked and recorded at constant motor wave amplitudes across the conditions. Suppression of Sol H-reflex amplitude was dependent (main effect p<0.0001) upon the phase of movement during arm cycling, but not during static positioning. Results suggest that locomotor central pattern generators may contribute to the phasic reflex modulation observed in this study.

The corpus callosum provides a physical and functional connection between the two hemispheres of the brain allowing interactions between homologous cognitive, sensory and motor areas. In humans, the integrity of transcallosal connections between motor cortices can be evaluated quickly and non-invasively using transcranial magnetic stimulation (TMS) via the ipsilateral silent period (iSP). While the technique has been known for 20 years, many issues remain unsolved regarding which methods are best to elicit the iSP as an index of transcallosal inhibition. In addition, there is still limited information regarding the influence of individualized factors such as age on iSP measurements. This thesis investigates how common physiological and methodological factors influence the iSP in order to establish this method as a reliable index to assess the integrity of the transcallosal pathway linking primary motor cortices. In the first series of experiments, we used a previously described TMS protocol to elicit iSPs [1] to investigate changes in motor transcallosal inhibition in relation to individual factors linked to age, hand preference and history of concussions. A second series of methodological experiments examined the effects of stimulation intensity on the iSP and to determine its inter-session reliability. Our first series of experiments provided evidence that advancing age and history of concussions in young athletes were each independently associated with alterations in transcallosal inhibition. This was evidenced by changes in the duration of transcallosal inhibition (DTI) and in the latency of transcallosal inhibition (LTI) derived from iSP measurements. These experiments also revealed that the degree of hand preference in young adults was reflected in measures of transcallosal inhibition, so that mixed-handed individuals (i.e., ambidextrous) exhibited evidence of more efficient transcallosal transmission than either strong right or left handed individuals. The second series of experiments focusing on methodological aspects showed that the iSP duration (though not its onset) was influenced by stimulation intensity, increasing linearly with intensity up to 140% of the resting motor threshold (RMT). Our analysis further revealed that the probability of eliciting detectable iSP also increased with increasing intensity up to 130% RMT before reaching a plateau. A stimulation intensity of 130% of RMT appears to be optimal to elicit iSPs in healthy participants. In a subsequent study, we showed that iSP elicited at this stimulation intensity (i.e., 130% RMT) had good inter-session reliability. In light of these investigations, we recommend for future studies that, in addition to contraction of the homologous muscles of the opposite hand as proposed by Giovannelli et al 2009, that an intensity of 130% RMT should be used to elicit the iSP when assessing transcallosal inhibition between motor cortices.

No description available.

The purpose of this thesis was to determine whether practice-induced adjustments and retention of a goal directed isometric motor accuracy task were similar between ipsilateral upper and lower limb and whether there is an ipsilateral transfer between upper and lower limbs. In addition, this thesis project aimed to determine whether motor output variability and the activity of the involved agonist and antagonist muscles could predict any of the above stated changes. Sixteen young adults (8 men, 8 women; 22.1 or - 2.1 years) performed 80 trials of goal directed isometric contractions that involved accurately matching a target force of 25% MVC in 200 ms, either with the upper limb or the lower limb followed by the other limb. After an interval of 48 hours, 10 trials similar to the practice trials were performed to examine retention. Feedback of performance was provided in the form of a force-time trajectory along with numerical error values for force and time on each trial. End-point error was quantified as the absolute deviation from the targeted force and time. Motor output variability was quantified as the SD of force, SD of time to peak force and SD of force trajectory. The practice-induced adjustments for force and time endpoint accuracy were similar for the two limbs, however, two days later, retention of the force accuracy was better with the upper limb compared with the lower limb. Practice-induced reduction and practice-to-retention increase in force and time endpoint error were predicted by respective changes in peak force and time to peak force trial-to-trial variability for both limbs. In addition, the changes in accuracy were predicted by the changes in the activity of the involved agonist and antagonist muscles. Nonetheless, the changes in muscle activity differed between the two limbs. The adjustments in muscle activity were also different during the practice session despite the fact that the rate of improvement was similar for the two limbs. Finally, there was an asymmetric transfer of force accuracy from the lower limb to the ipsilateral upper limb, which was associated with the changes in motor output variability. The upper limb, which is inherently less variable as compared to the lower limb, may have retained the task better due to the formation of a stronger muscle synergy (or stronger internal model) to perform the contractions with accuracy. The lower limb, on the other hand may have formed a weaker internal model due to the greater interference from amplified signal-dependent noise (motor output variability) or an alternative motor plan, which may have been concerned primarily with the minimization of motor output variability instead of formation of a muscle synergy to perform the contractions accurately.

Many cells in the inferior colliculus (IC) are excited by contralateral and inhibited by ipsilateral stimulation and are thought to be important for sound localization. These excitatory-inhibitory (EI) cells comprise a diverse group, even though they exhibit a common binaural response property. Previous extracellular studies proposed specific excitatory and/or inhibitory events that should be evoked by each ear and thereby generate each of the EI discharge properties. The proposals were inferences based on the well established response features of neurons in lower nuclei, the projections of those nuclei, their excitatory or inhibitory neurochemistry, and the changes in response features that occurred when inhibition was blocked. Here we recorded the inputs, the postsynaptic potentials, discharges evoked by monaural and binaural signals in EI cells with in vivo whole cell recordings from the inferior colliculus (IC) of awake bats. We also computed the excitatory and inhibitory synaptic conductances from the recorded sound evoked responses. First, we showed that a minority of EI cells either inherited their binaural property from a lower binaural nucleus or the EI property was created in the IC via inhibitory projections from the ipsilateral ear, features consistent with those observed in extracellular studies. Second, we showed that in a majority of EI cells ipsilateral signals evoked subthreshold EPSPs that behaved paradoxically in that EPSP amplitudes increased with intensity, even though binaural signals with the same ipsilateral intensities generated progressively greater spike suppressions. These ipsilateral EPSPs were unexpected since they could not have been detected with extracellular recordings. These additional responses suggested that the circuitry underlying EI cells was more complex than previously suggested. We also proposed the functional significance of ipsilaterally evoked EPSPs in responding to moving sound sources or multiple sounds. Third, by computing synaptic conductances, we showed the circuitry of the EI cells was even more complicated than those suggested by PSPs, and we also evaluated how the binaural property was produced by the contralateral and ipsilateral synaptic events. / text

Performance of efficient and precise motor output requires proper planning of movement parameters as well as integration of sensory feedback. Peripheral sensory information is projected not only to parietal somatosensory areas but also to cortical motor areas, particularly the supplementary motor area (SMA). These afferent sensory pathways to the frontal cortices are likely involved in the integration of sensory information for assistance in motor program planning and execution. It is not well understood how and where sensory information from the limb contralateral to motor output is modulated, but the SMA is a potential cortical source as it is active both before and during motor output and is particularly involved in movements that require coordination and bilateral upper-limb selection and use. A promising physiological index of sensory inflow to the SMA is the frontal N30 component of the median nerve (MN) somatosensory-evoked potential (SEP), which is generated in the SMA. The SMA has strong connections with ipsilateral areas 2, 5 and secondary somatosensory cortex (S2) as well as ipsilateral primary motor cortex (M1). As such, the SMA proves a fruitful candidate to assess how sensory information is modulated across the upper-limbs during the various stages of motor output. This thesis inquires into how somatosensory information is modulated in both the SMA and primary somatosensory cortical areas (S1) during the planning and execution of a motor output contralateral to sensory input across the upper-limbs, and further, how and what effect ipsilateral primary motor cortex (iM1) has upon modulation of sensory inputs to the SMA.

Performance of efficient and precise motor output requires proper planning of movement parameters as well as integration of sensory feedback. Peripheral sensory information is projected not only to parietal somatosensory areas but also to cortical motor areas, particularly the supplementary motor area (SMA). These afferent sensory pathways to the frontal cortices are likely involved in the integration of sensory information for assistance in motor program planning and execution. It is not well understood how and where sensory information from the limb contralateral to motor output is modulated, but the SMA is a potential cortical source as it is active both before and during motor output and is particularly involved in movements that require coordination and bilateral upper-limb selection and use. A promising physiological index of sensory inflow to the SMA is the frontal N30 component of the median nerve (MN) somatosensory-evoked potential (SEP), which is generated in the SMA. The SMA has strong connections with ipsilateral areas 2, 5 and secondary somatosensory cortex (S2) as well as ipsilateral primary motor cortex (M1). As such, the SMA proves a fruitful candidate to assess how sensory information is modulated across the upper-limbs during the various stages of motor output. This thesis inquires into how somatosensory information is modulated in both the SMA and primary somatosensory cortical areas (S1) during the planning and execution of a motor output contralateral to sensory input across the upper-limbs, and further, how and what effect ipsilateral primary motor cortex (iM1) has upon modulation of sensory inputs to the SMA.