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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Resposta morfológicas e moleculares do músculo esquelético de ratos idosos submetidos ao treinamento físico após estímulo atrófico /

Vechetti Júnior, Ivan José. January 2015 (has links)
Orientador: / Coorientador: / Banca: / Resumo: Introdução: Durante o envelhecimento, a perda de massa muscular (sarcopenia) é inevitável e contribui para a elevada morbidade e mortalidade; assim, evitar a sarcopenia é importante para manutenção da saúde e qualidade de vida a longo prazo. Além disso, o treinamento físico tem sido demonstrado ser importante para o controle de massa muscular durante o envelhecimento através da ativação de várias vias incluindo, IGF1-AKT e PGC-1α. Além disso, foi demonstrado que LRP130, um componente do complexo do PGC-1α é importante para a transcrição dependente de vários genes mitocondriais in vivo. Portanto, nós hipotetizamos que o treinamento físico pode melhorar a recuperação muscular, possivelmente através do complexo PGC-1α/LRP130 por inibição do sistema ubiquitina-proteassoma após atrofia induzida por desuso em ratos idosos. Portanto, foi investigado os efeitos do processo de regeneração muscular após curto período de imobilização seguido de 3 ou 7 dias de recuperação utilizando treinamento aeróbio (AT) ou treinamento resistido (TR). Métodos: Após 7 dias de imobilização, os animais foram submetidos ao processo de recuperação muscular com exercício (AT ou RT) ou sem exercício (R) durante 3 ou 7 dias. No final do experimento, os animais foram sacrificados, e o músculo plantar (PL) foi removido para análises morfológicas (avaliação da atividade mATPase, para avaliar a área de secção transversal das fibras musculares (CSA), bem como a frequência dos tipos de fibras específicas), análises bioquímicas (isoformas da cadeia pesada de miosina, MyHC), expressão gênica de 44 marcadores moleculares de massa muscular (RT-qPCR). Para entender melhor a relevância biológica das interações de mRNA, foi realizada uma análise de rede que estão relacionados com o nosso conjunto de genes diferencialmente expressos (plugin GeneMANIA Cytoscape). Os genes diferencialmente expressos foram submetidos à análise... / Abstract: Background: During aging, loss of muscle mass (sarcopenia) is inevitable and contributes to increased morbidity and mortality; thus, the maintenance of skeletal muscle mass is critical for long-term health and quality of life. In addition, physical training has been shown to be important to the control of muscle mass during aging through the activation of several pathways including, IGF1-AKT and PGC-1α. Also, it was demonstrated that LRP130, a component of the PGC-1α complex is important for the PGC-1α- dependent transcription of several mitochondrial genes in vivo. Therefore, we hypothesized that the physical training could improve the muscle recovery possibly through of the LRP130/PGC-1α complex by inhibiting the ubiquitin-proteasome system after disuse-induced atrophy in aged rats. We therefore investigated the effects on muscle recovery after short-term immobilization followed by 3 or 7 days of retraining with aerobic training (AT) or resistance training (RT). Methods: After 7 days of immobilization, the animals underwent the re-growth process with exercise (AT or RT) or without exercise (R) for 3 or 7 days. At the end of the experiment, the animals were sacrificed, and the plantaris (PL) muscle was removed for morphological analyses (assessment of mATPase activity, to assess the total muscle fiber cross sectional area (CSA), and the frequency of specific fiber types), biochemical analyses (Myosin Heavy Chain, MyHC), gene expression of 44 molecular markers of muscle mass (RT-qPCR). To further understand the biological relevance of the mRNA interactions, we performed a search for additional genes that are related to our differentially expressed gene set (GeneMANIA Cytoscape plugin). Differentially expressed genes were submitted to Western blotting analysis. Results: At 7 days after an atrophic stimulus, only PL muscles from animals subjected to AT had recovered their normal CSA patterns. The frequency of fiber types and ... / Doutor
142

Musculoskeletal and perceptual responses of batsmen comparing high- and moderate-volume sprints between the wickets

Sheppard, Bronwyn Jane January 2012 (has links)
Background: Literature has associated repeated eccentric muscle actions with increased muscle damage of the muscles involved. Eccentric actions are typical in sports which are ‘stop-start’ in nature requiring rapid acceleration and deceleration, typical of a batting activity in cricket. Ultra-structural damage of the skeletal muscle as a consequence of repeated decelerating activities is associated with performance decrements, particularly muscle strength and sprinting speeds. This suggests that eccentric strength decrements may provide an indication for the development of muscle strain injuries during these activities. Despite these findings, limited research has identified the specific musculoskeletal demands placed on cricket batsmen, particularly with reference to various match intensities. Objective: The present study, therefore, sought to determine the specific musculoskeletal, physiological and perceptual demands placed on specialised batsmen during two work bouts of different intensities; one representing a highintensity work bout and the other a moderate-intensity work bout. The dependent variables of interest were muscle activation, isokinetic strength changes, heart rate, ‘central’ and ‘local’ ratings of perceived exertion (RPE), body discomfort and performance. Methods: The two experimental conditions, representative of a high- (HVR) and moderate-volume running (MVR) batting protocol, required players to perform a simulated batting work bout of either twelve or six runs an over, within a laboratory setting. Selected physiological, perceptual and performance measures were collected at specific time intervals throughout the work bout while the biophysical measures were collected prior to, and following both protocols. Results: Of the variables measured, heart rate, ‘central’ and ‘local’ RPE values were observed to increase significantly (p<0.05) over time. This increase was greater as a consequence of the HVR in comparison to the MVR. No change in sprint times was documented during the MVR, in contrast, significant (p<0.05) increases over time were observed during the HVR, further highlighting the elevated demands associated with this condition. In addition, an ‘end spurt’ was observed particularly following the HVR condition, suggesting athletes were conserving themselves through the adoption of a pacing strategy. Reductions in biceps femoris and semitendinosus muscle activation levels were observed following the HVR. This was further supported by the significantly greater levels of semitendinosus activation following the MVR when compared to the HVR. Peak concentric and eccentric knee extensor (EXT) (-17.17% and -16.07% respectively) and eccentric flexor (FLEX) (- 17.49%) values decreased significantly (p<0.05) following the HVR at 60°.s-1. In addition, concentric and eccentric total work produced by the flexors and eccentric extensors resulted in significantly (p<0.05) lower values due to the HVR. Conclusion: The intermittent high-volume batting work bout elicited elevated mean heart rates, perceived ratings of cardiovascular and muscular effort and sprint times. Furthermore, hamstring activation levels and muscle strength, particularly concentric strength of the dominant lower limb were negatively affected by the HVR condition. These results suggest elevated demands were placed on the hamstring musculature as a consequence of the HVR condition, indicating a greater degree of musculoskeletal strain and increased injury risk associated with running between the wickets at this intensity, representative of an aggressive batting scenario.
143

An Epidemiological Survey of Musculoskeletal Pain Among a Self-Selected Population of Organists

Dillard, E. Margo (Edna Margo) 05 1900 (has links)
The purpose of this study was to investigate problem areas of organists' performance as indicated by common experiences of pain. The research problems were to determine the specific areas of the body that were affected by pain, to determine the perceived level of that pain on a scale indicative of its severity, and to explore the relationship between demographic and performance-related factors within the population and specific area of reported pain. An examination of the demographic, performance-related, and pain data, as well as subject comments, indicated possible relationships of the pain experience to other factors. Organists attributed their pain to instrument characteristics, such as keyboard action, music rack height, bench design, and pedalboard shape. Pain was also associated with the time spent playing the organ, playing literature which required large reaches and rapid passage work, such as french toccatas, or playing with incorrect posture. To explore these relationships to spinal and upper extremity pain, further research is indicated.
144

Acoustic Detection of Developmental Dysplasia of the Hip in Models Representing Neonates

Raodeo, Pinak 01 January 2021 (has links)
Developmental dysplasia of the hip (DDH) is a condition that involves the dislocation of the head of the femur in the acetabulum of the pelvic bone. Although it may not interfere with a child's range of motion during infancy, DDH can cause various effects over time such as joint pain, abnormal gait, and even paralysis. It is crucial to catch this phenomenon early on so that permanent disability is not introduced to the patient. In this study, an excitation device was used to send a broadband frequency signal through a hip joint simulated by a 3D printed bone apparatus consisting of a left femur and left pelvic bone. Accelerometers were used to sense the transmission of this signal through the bones tested. Variability was induced through different experiments in order to determine where the optimal frequency for detection of DDH would be. After variability was quantified for all of the nonconsecutive and consecutive trials, the excitation device was tested on a raw chicken quarter through the knee joint since this was very similar to the hip joint. Coherence, phase, and transfer function graphs were used to demonstrate the degree of variability, optimal frequencies for detection, and degree of signal transmission through the joints tested. The results from the 3D printed bone model showed that the height of accelerometer suspension, loosened coupling of sensors, and vertical alignment of the bone model apparatus affected the transfer function and phase graphs of the experiments while coherence stayed relatively the same. On the other hand, the results from the raw chicken model displayed similarities between graphs for little to no joint dislocation but the complete dislocation of the bone yielded significantly different graphs.
145

Factors regulating arteriolar tone during microvascular growth

Balch Samora, Julie. January 2007 (has links)
Thesis (Ph. D.)--West Virginia University, 2007. / Title from document title page. Document formatted into pages; contains xxiii, 251 p. : ill. Vita. Includes abstract. Includes bibliographical references.
146

The impact of n-3 PUFA supplementation on human skeletal muscle metabolism

McGlory, C. January 2014 (has links)
The time course of this increase in muscle n-3 PUFA composition and anabolic protein expression is currently unknown. In Chapter 2 of this thesis ten healthy male participants consumed 5g.d-1 of n-3 PUFA-enriched fish oil for 4 weeks. Muscle biopsies samples were collected in the fasted, rested state 2 weeks prior, immediately before (Week 0), at Week 1, Week 2 and Week 4 after initiation of fish oil supplementation for assessment of changes in lipid composition and expression of anabolic signalling proteins over time. Muscle lipid profile, (% total n-3 PUFA/total fatty acids) increased from W0 to W2 (3.8 ± 0.2 to 5.1 ± 0.3 %) and continued to rise at W4 (6.7 ± 0.4 %). Total protein content of FAK increased from W0 to W4 (3.9 ± 1.5 fold) whereas total mTOR was increased from W0 at W1 (2.4 ± 0.6 fold) with no further significant increases at W2 and W4. For the first time this study demonstrates that oral fish oil consumption results in an increase of n-3 PUFA levels in human skeletal muscle that is associated with increases in the expression of anabolic signalling proteins. Our understanding of the anabolic signalling process that underpins muscle protein synthesis has been advanced by the application of the WB technique. However, the semi-quantitative nature and poor dynamic range associated with the WB technique may lead to incongruence regarding the molecular response of skeletal muscle to anabolic stimulation. Chapter 3 of this thesis developed and applied a quantitative in vitro [γ-32P] ATP kinase assay (KA) alongside a traditional WB methodology to assess p70S6K1 signalling responses in human skeletal muscle to RE and protein feeding. Following validation in tissue culture with rapamycin and optimization of the assay in human skeletal muscle, this methodology was tested in a physiologically relevant context. In this regard, six males performed unilateral resistance exercise (RE) followed by the consumption of 20 g of protein. Skeletal muscle biopsies were obtained at pre-RE, at 1 h and 3 h post-RE. In response to RE and protein consumption, p70S6K1 activity was significantly increased from pre-RE at 1 h and 3 h post-RE (8.84 ± 0.78 to 17.18 ± 2.62 and 15.62 ± 3.12 µU/mg). However, phosphorylated p70S6K1thr389 was not significantly elevated. To assess if a combined stimulus of RE and feeding can influence AMPK activity we directly measured AMPK activity. AMPK activity was suppressed from pre-RE at 3 h post-RE (24.15 ± 1.6 to 15.64 ± 1.07 mU/mg), whereas phosphorylated ACCser79 was unchanged. These data therefore highlight the utility of the KA to study skeletal muscle plasticity. Previous studies have shown that ingestion of n-3 PUFA potentiates the phosphorylation of mTORC1 and associated kinases in response to nutrition. However, no study has identified whether n-3 PUFA supplementation potentiates anabolic kinase activity when RE is performed prior to nutrient provision. In Chapter 4 of this thesis, twenty healthy males consumed 5g.d-1 of either fish oil (FO) or coconut oil (CO) capsules for 8 weeks. Muscle biopsy samples were collected in the fasted, rested state before and after 8 weeks of supplementation for assessment of changes in lipid composition. Following 8 weeks of supplementation muscle samples also were obtained at rest (Rest), post RE in both the exercise leg (Post-RE) and the rested leg (Pre-FED) and also at 3 h post RE and protein feeding from both the exercise leg (3 h post-REF) and rested leg (3 h post-FED). There was a 2-fold increase in muscle (5.53 ± 0.3 to 11.16 ± 0.45 % of total fatty acids) n-3 PUFA composition after supplementation in the FO group but no change in the CO group. Following supplementation there was an increase in p70S6K1 activity at 3 h post-REF from Rest in the CO group (5.6 ± 1.4 to 12.2 ± 2.1 µU/mg) but no change in the FO group. In the CO group, AMPKα2 was significantly increased at Post-RE from Rest (3.7 ± 0.7 to 9.9 ± 2.0 mU/mg). These data show that 8 weeks of n-3 PUFA enriched fish oil supplementation suppresses the activity of p70S6K1 in response to RE and protein feeding.
147

TEMPORAL NEUROMUSCULAR ALTERATIONS OF THE QUADRICEPS AFTER UNILATERAL ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

Gabler, Conrad M. 01 January 2016 (has links)
Objective: The primary aim of this research was to examine the temporal pattern of neuromuscular quadriceps deficits in both the involved and uninvolved limbs of patients assigned to the control group after anterior cruciate ligament reconstruction (ACLr), by assessing quadriceps strength, voluntary activation, and corticomotor excitability prior to surgery (baseline), three months after ACLr, and six months after ACLr. A secondary aim of this research was to determine whether quadriceps strength, voluntary activation, and/or corticomotor excitability assessed in patients prior to ACLr and/or at three months after surgery, is predictive of lower extremity postural control and/or self-reported function at six months after ACLr. Lastly, a tertiary aim of this research was to determine if a 12-week home-based neuromuscular electrical stimulation (Home-NMES) program elicits greater bilateral improvements in quadriceps strength, voluntary activation, and corticomotor excitability of patients at three and six months after ACLr compared to a 12-week standard home-exercise program (control group). Participants: Fifty patients scheduled to undergo unilateral ACLr were randomly allocated to the home-NMES group (19 Female, 6 Male; age: 18.9 ± 5.4 years; height: 170.8 ± 9.7 cm; weight: 74.6 ± 18.5 kg; 28.0±20.0 days-post-injury) or control group (14 Female, 11 Male; age: 19.4 ± 4.5 years; height: 171.1 ± 11.5 cm; weight: 70.7 ± 11.9 kg). Methods: A randomized clinical trial design was used in this study. Prior to ACLr, isometric quadriceps strength and voluntary quadriceps activation were assessed in both limbs of patients, and corticomotor excitability was assessed in the involved limb. Three days after ACLr, both groups were instructed to begin their allocated interventions. The Home-NMES group administered NMES to their involved limb’s quadriceps three sessions a day for 15 minutes, and five days a week for 12 weeks using a portable NMES device. The control group was treated according to the current standard-of-care, but they were also instructed to perform volitional isometric quadriceps contractions for the same duration and frequency as the Home-Based NMES protocol. The outcomes measures were reassessed in both groups at three and six months post-ACLr. Main Outcome Measures: Quadriceps strength and voluntary activation were assessed using maximal voluntary isometric contractions and the superimposed burst technique, respectively. Normalized peak knee extension torque and central activation ratio were used to quantify isometric quadriceps strength and activation, respectively. Corticomotor excitability was evaluated with transcranial magnetic stimulation, and quantified with active motor threshold). The Y-balance test anterior reach (YBT-A) and Knee Injury and Osteoarthritis Outcome Score (KOOS) were used to assess the patients lower extremity knee function at six months post-ACLr. Statistical Analyses: Specific Aim 1: A 2x3 (limb x time) mixed model, ANOVA with repeated measures was performed in the control group to assess differences between the involved limb and the uninvolved limb for isometric quadriceps strength, and voluntary quadriceps activation over time. A one-way mixed model, ANOVA with repeated measures was performed in the control group to assess differences in corticomotor excitability over time. Post-hoc comparisons were performed when appropriate. Specific Aim 2: Separate, mixed model, linear regression analyses were performed in the control group (involved limb) to determine the effect that the neuromuscular quadriceps outcome measures assessed at baseline and 3 months post-ACLr, had on lower extremity knee functional outcome measures assessed at 6 months post-ACLr. Specific Aim 3: A 2x2x3 (group x limb x time) mixed model, ANOVA with repeated measures was performed to assess group differences between the involved limb and the uninvolved limb in isometric quadriceps strength, and voluntary quadriceps activation over time. A 2x3 (group x time) mixed model, ANOVA with repeated measures was performed to assess group differences in corticomotor excitability over time. Post-hoc comparisons were performed when appropriate. Results: Aim 1: Patients demonstrated lower quadriceps strength on their involved limb compared to their uninvolved limb at baseline, three months post-ACLr, and six months post-ACLr. Quadriceps strength progressively decreased in the involved limb of patients from baseline to 3 months post-ACLr, baseline to 6 months post-ACLr, and increased from 3 months to 6 months post-ACLr. Quadriceps strength was also decreased in the uninvolved limb of patients from baseline to 6 months post-ACLr. ). Irrespective of when it was assessed, voluntary quadriceps activation was higher in the involved limb of patients compared to their uninvolved limb. There were no changes in corticomotor excitability of the involved limb over time. Specific Aim 2: The quadriceps strength of patients at three months post-ACLr had a significant positive effect on their 6-month YBT-A performance KOOS score. ). Neither voluntary quadriceps activation or corticomotor excitability or AMT (at baseline or 3-month post-ACLr) had a significant effect on any of the 6-month lower extremity functional outcome measures. Specific Aim 3: Irrespective of limb or when it was assessed, quadriceps strength was higher in the control group compared to the Home-NMES group. Both groups demonstrated lower quadriceps strength on their involved limbs compared to their uninvolved limbs at baseline, three months post-ACLr, and six months post-ACLr. Quadriceps progressively decreased in the involved limbs of both groups from baseline to three months post-ACLr and baseline to six months post-ACLr, and increased from three months to six months post- ACLr. At baseline, voluntary quadriceps activation was higher in the involved limbs of both groups compared to their uninvolved limbs. There were no group differences or changes over time observed in the involved limb of both groups with corticomotor excitability. Conclusion: Although quadriceps weakness is more apparent in the involved limb of patients after ACLr, the quadriceps strength of their uninvolved limb was also affected. Clinicians are encouraged to not rely on a quadriceps strength limb symmetry index when making return-sport-decisions for their patients after recovering from ACLr. The quadriceps in the uninvolved limb of patients demonstrated more inhibition, which may explain the quadriceps strength deficits observed in the uninvolved limb of patients following ACLr. To reduce the risk of subsequent injury upon return-to-sport and protect against the development of knee OA, we recommend that clinicians incorporate bilateral interventions aimed at restoring quadriceps strength and disinhibiting the quadriceps. Intensive quadriceps strengthening should be performed in the early stages of ACLr rehabilitation, so that lower extremity function can be improved in patients later on. Lastly, the effectiveness of home-based NMES as a modality for restoring quadriceps strength and activation in patients after ACLr is inconclusive. Home-based NMES provides patients with the ability to receive higher doses of NMES to the quadriceps; but its effectiveness may be limited by low contraction intensities and poor treatment compliance in patients.
148

The effects of acute hypoxia on metabolic enzymes in skeletal muscle

De Bie, Gabrielle 03 1900 (has links)
Thesis (MPhil (Physiological Sciences))--University of Stellenbosch, 2006. / The responses of central systems to oxygen deprivation have been well characterised while adaptations in peripheral systems, such as skeletal muscles, have presented confounding variations. Several reasons for these discrepancies are purported, amongst them being the duration of exposure to hypoxia and variations in fibre composition. Moreover, in real-life high altitude situations there may be a combination of factors which have the ability to modify or alter the effect of hypoxia. This study investigates the effect of short duration hypoxia per se on substrate utilisation in different types of skeletal muscles.
149

Proximal feed artery regulation of skeletal muscle blood flow during exercise : the paraplegic model

Scriba, E. W. (Ernst Wolfgang) 12 1900 (has links)
Assignment (MPhil)--University of Stellenbosch, 2003. / ENGLISH ABSTRACT: The mechanisms of blood flow (BF) control to skeletal muscle during dynamic exercise are still not clearly understood. The paraplegic subject (P) has reduced sympathetic innervation to the lower limbs. The current study was designed to focus on the contribution of neural control, specifically the sympathetic nervous system (SNS), as part of the central vascular mechanism to skeletal muscle BF during dynamic exercise. Aims: We studied BF parameters in P vs. able-bodied subjects (AB) to determine whether the paraplegic can serve as a model for assessing the contribution of the SNS to changes in active vs. inactive muscle BF during exercise. Further questions addressed include: the influence of level of fitness on resting and exercise BF, how lesion level affects BF control in the paraplegic, the 'muscle pump' theory and its hypothesized role in exercise hyperemia and whether blood pooling occurs in the legs of paraplegics. Method: Noninvasive duplex Doppler studies of the large conduit arteries (brachial and common femoral) were performed on 10 elite paraplegic athletes (EP), 10 sedentary paraplegics (SP) en 10 sedentary able-bodied subjects (AB). The paraplegic groups were further subdivided by lesion level with T6 being the critical level. Tests were carried out at rest and after 2 bouts of arm ergometer exercise: a maximal incremental test and 3 minutes at 75% of maximal. Diameter, mean velocity, pulsatile index and blood flow were measured/calculated. Results: Resting heart rate was significantly higher in the paraplegic groups (EP = 80 bpm ± 10, SP = 83 bpm ± 12) vs. the AB group (69 bpm ± 7), p < 0.05. Resting diameter in the common femoral artery (CFA) was similar in EP (5.93 mm ± 1.54) and SP (6.52 mm ± 0.95), but significantly lower than in AB (7.87 mm ± 1.38), p < 0.05. Similar resting pulsatile index (PI) in the CFA were contrary to that previously reported, casting doubt on venous blood pooling theories. Post-exercise values need to be interpreted with caution in view of the large resting differences in CFA diameter. Percentage change values are therefore more appropriate. These differences were not statistically significant, but may suggest interesting trends. Large variability existed for most resting and post-exercise values. Conclusion: The paraplegic subject is an ideal model for the study of the influence of the SNS on blood supply to exercising skeletal muscle. The difference in CFA diameter at rest in the paraplegic vs. the AB group confirms previous results and is probably due to structural/non-physiological changes. Our observation that the BA and CFA diameters in EP and SP subjects do not differ significantly at rest, suggests that training does not have a spillover vasomotor effect on lower limb conduit arteries in paraplegia. Similar BF and PI values post-exercise in the SP and AB groups challenge the muscle pump theory. The SNS has an important role in the control of skeletal muscle blood flow - both at rest (vascular tone) and during exercise (redistribution). Suggestions for future research are made. / AFRIKAANSE OPSOMMING: Die meganismes betrokke by die beheer van bloedvloei (BV) gedurende dinamiese oefening is nog onduidelik. Die parapleeg (P) het verminderde simpatiese innervasie na die onderste ledemate. Die huidige studie fokus op die bydrae van die simpatiese senuwee sisteem (SSS), as deel van die sentrale vaskulêre meganisme, tot skeletale spier BV tydens dinamiese oefening. Doelstellings: Ons het BV parameters in P vs. nie-gestremde proefpersone (kontrole) bestudeer om vas te stelof die parapleeg as model gebruik kan word om die bydrae van die SSS tot veranderings in die BV in aktiewe- en onaktiewe spiere gedurende oefening, te ondersoek. Verdere aspekte wat ondersoek is, sluit in: die invloed van tiksheidvlak ten opsigte van rustende en oefenings BV, of die verlammingsvlak by die parapleeg BV kontrole beïnvloed, die 'spierpomp-teorie' en sy hipotetiese rol in oefeninghiperremie, asook die vraag of bloedsaamstorting in die bene van parapleë plaasvind. Metode: Nie-indringende duplex Doppler studies van die groot geleidingsarteries (bragiaal [BA] en gemene femoral [CFA]) is by 10 elite paraplegiese atlete (EP), 10 sedentêre parapleë (SP) en 10 sedentêre nie-gestremde proefpersone (AB) uitgevoer. Die paraplegiese proefpersone is verder onderverdeel deur die vlak van T6 as kritiese verlammingsvlak te gebruik. Toetse is tydens rus en na 2 arm-ergometer oefeningsessies uitgevoer: een maksimale inkrementeie toets en een van 75% van maksimum intensiteit. Deursnit, gemiddelde vloeispoed, pulsatiewe indeks en bloedvloei is gemeet en/of bereken. Resultate: Rustende hartspoed was beduidend hoër in die paraplegiese groepe (EP = 80 slaelminuut ± 10 en SP = 83 slm ± 12) vs. die AB groep (69 slm ± 7), p < 0.05. Rustende deursnit in die gemene femorale arterie (CFA) was dieselfde in EP (5.93 mm ± 1.54) en SP (6.52 mm ± 0.95), maar beduidend laer as in AB (7.87 mm ± 1.38), p < 0.05. Die feit dat rustende pulsatiewe indeks (PI) in die CFA dieselfde in albei groepe was, laat twyfelontstaan oor die veneuse bloedopdammings teorieë soos weergegee in die literatuur. Na-oefeningswaardes moet omsigtig evalueer word met inagneming van die groot rustende verskille in CFA deursnit. Persentasieverskilwaardes is dus meer toepaslik. Hierdie veskille was nie statisties beduidend nie, maar suggereer interessante tendense. Groot variasie het voorgekom vir beide rustende en na-oefenings waardes. Gevolgtrekking: Die parapleeg is 'n ideale model vir studies om die invloed van die SSS op bloedvloei aan aktiewe skeletale spier te bestudeer. Die verskil in rustende CFA deursnit in die parapleeg vs. die AB groep bevestig vorige resultate en is waarskynlik te wyte aan strukturele, nie-funksionele veranderinge. Ons bevindinge dat die BA en CFA deursneë nie beduidend verskil in die SP en EP groep gedurende rus nie, dui daarop dat gereëlde oefening nie 'n oorloop vasomotor effek op die onderste ledemate in die parapleeg het nie. Die feit dat daar geen verskil aangetoon kon word tussen BV en PI waardes na-oefening in die SP en AB groepe, betwis die spierpomp teorie. Die studie toon dat die SSS 'n belangrike rol in die beheer van skeletale spier bloedvloei speel - beide met rus (vaskulêre tonus) en gedurende oefening (herdistribusie). Voorstelle vir toekomstige navorsing word gemaak.
150

Anti-bacteria plasma-treated metallic surface for orthopaedics use

Leung, Kit-ying, 梁潔瑩 January 2008 (has links)
published_or_final_version / Orthopaedics and Traumatology / Master / Master of Philosophy

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