M.Tech. (Chiropractic) / Aim of this study was to compare which treatment either Proprioceptive Neuromuscular Facilitation or chiropractic manipulation, whether by itself or in combination, was more effective and beneficial in the treatment of mechanical neck pain. The effectiveness was measured by the use of a Visual Analogue Scale, Vernon- Mior Neck Pain and Disability Index questionnaire and the measurement of cervical spine range of motion using an analogous cervical spine range of motion inclinometer (CROM). The questionnaire and the measurements were taken prior to the treatments at the first, fourth and seventh consultations.Thirty participants who met the inclusion criteria were randomly placed into three groups of equal size (10 participants each). Group one received a Proprioceptive Neuromuscular Facilitation (PNF) stretching protocol to the cervical spine. Group two received a chiropractic manipulation to the cervical spine. Group three received a combination treatment, first receiving chiropractic manipulation and then a PNF stretching protocol to the cervical spine. Participants were treated six times out of a total of seven sessions, over a maximum of a three week period.Subjective data was collected at the beginning of the first, fourth and seventh consultations. This was done by means of a Visual Analogue Scale and a Vernon-Mior Neck Pain and Disability Index Questionnaire, in order to assess pain and disability levels. Objective data was collected by means of measuring cervical spine range of motion using a cervical range of motion (CROM) inclinometer. Analysis of collected data was performed by a statistician from STATKON, a department of the University of Johannesburg.Clinically significant improvements in group 1, group 2 and group 3 were noted over the duration of the study with reference to pain and disability. Statistically significant changes were seen in all three groups with reference to pain and disability. Group 3 was shown to improve the most with regard to pain and disability. Group 1 had statistically significant improvement with regard to cervical range of motion in the ranges of left and right rotation. Group 2 experienced a decrease range of cervical motion with regard to extension. As the study consisted of a small group of participants further, more extensive studies are needed...

Au niveau de la circulation pulmonaire, une exposition prolongée à l’hypoxie est responsable du phénomène de vasoconstriction hypoxique pulmonaire (VHP) qui favorise les échanges gazeux. Lorsque cette VHP se généralise, elle conduit au développement d'une hypertension pulmonaire de groupe 3 (HTP). Cette pathologie se caractérise par un remodelage vasculaire induisant une élévation progressive de la pression artérielle pulmonaire (> 25 mmHg au repos). Ceci conduit à une défaillance cardiaque droite et, à terme, à la mort. La VHP est responsable de l'étirement de la membrane des cellules musculaires lisses des artères pulmonaires (CMLAP) et peut ainsi activer des "Stretch-Activated Channels" tels que les TRPV (Transient Receptor Potential Vanilloid). Il a précédemment été décrit que les canaux TRPV1 et TRPV4, impliqués dans la migration et la prolifération des cellules vasculaires pulmonaires, sont surexprimés et suractivés lors de l'HTP. Cependant, ces modifications peuvent être dues à un effet direct de l’hypoxie ou indirect, conséquence d'un étirement membranaire plus important induit par la VHP. Nous avons donc étudié la contribution respective des stress hypoxique et mécanique, observés en contexte d’HTP, en utilisant des conditionnements in vitro sur des CMLAP d’animaux sains (rats et souris). Nous avons montré que l’hypoxie (1 % O2, 48 heures) induit une augmentation de la [Ca2+]i couplée à une potentialisation de la migration induite par l’activation de TRPV1 et V4. De même, un étirement cyclique (20 %, 1 Hz, 24 heures) provoque une augmentation de la [Ca2+]i et de la prolifération. Ces résultats montrent pour la première fois une action directe de l'hypoxie et du stress mécanique (étirement cyclique) sur des CMLAP. / Hypoxia exposure induces hypoxic pulmonary vasoconstriction (HPV) allowing the efficiency of gas exchanges by increasing the intraluminal pressure. Prolonged hypoxia leads to pulmonary hypertension of group 3 (PH), characterized by increased pulmonary pressure (> 25 mmHg), leading to right ventricular heart failure and ultimately death. HPV leads to stretch pulmonary artery smooth muscle cell (PASMC) membranes inside the vascular wall and thus can activate "Stretch-Activated-Channels" such as TRPV channels (Transient Receptor Potential Vanilloid). It has been previously shown that TRPV1 and TRPV4 channels, implicated in PASMC migration and proliferation, are overexpressed and overactivated in PASMC in the context of PH. But whether this feature is directly caused by hypoxia alone or is a consequence of stretch induced by the HPV is a matter of debate. We thus investigated the respective contribution of hypoxia and mechanical stresses observed in the context of PH using in vitro conditionings on PASMC from healthy animals (rats and mice). We showed that hypoxia (1 % O2, 48 hours) increases Ca2+ entry through TRPV4 channels as well as PASMC migration induced by TRPV1 and TRPV4 activation. Furthermore, cyclic stretch conditioning (20 %, 1 Hz, 24 hours) triggers Ca2+ increase and PASMC proliferation. This work shows for the first time the direct implication of both hypoxia and mechanical stress (cyclic) stretch on PASMC.

Tidigare forskning visar på ett positivt samband mellan styrketräning och löpekonomi. I föreliggande studie undersöktes effekten av djupa explosiva knäböjningar på löpekonomin hos långdistanslöpare. I studien deltog elva deltagare varav sex i interventionsgruppen och fem i kontrollgruppen. Styrketräningen skulle vara tidseffektivt, max 20 min och då enbart en övning. Basövningen knäböjning med stången bakom nacken valdes. Huvuddelen av all knäböjsträning under en åtta veckors period, utfördes med en belastning på 60% av 1RM 2-6 rep i 2-6 set och då med fokus hög hastighet i både den excentriska och koncentriska fasen samt ca 1 min vila mellan seten. Efter avslutad träningsperiod sågs signifikant förbättring vad gäller maxstyrka, 1RM och maximal Power. Samtliga deltagare i interventionsgruppen fick en positiv styrkeökning med ett snitt på 14,5%. Studien visar även en tendens till förbättrad löpekonomi hos interventionsgruppen. / Previous research shows a positive link between strength training and running economics. In the present study, the effect of deep power squats on the running economics of long distance runners was investigated. The study included eleven participants, six were in the intervention group and five in the control group. The strength training would be time efficient, max 20 min and then only one exercise. We chose the basic exercise squats with the barbell behind the neck. The majority of all squats exercises during a period eight week with a load of 60% of 1RM 2-6 reps in 2-6 sets and then focused high speed in both the eccentric and concentric phase and about 1 min rest between the sets. At the end of the training period, we could see a significant improvement in maximal 1RM and maximum Power. All participants in the intervention group received a positive increase in strength, with an average of 14.5%. The study also shows a tendency for improved running economics in the intervention group.

Abstract During cardiac hypertrophy individual cardiac myocytes increase in size, which is accompanied by augmented protein synthesis and selective induction of a subset of genes. These phenotypic changes of myocytes are a result from altered intracellular signaling mechanisms and molecules. B-type natriuretic peptide (BNP) gene was selected as a target gene for the study of cardiac signaling mechanisms, since it is activated by mechanical, neural and humoral stimuli during myocyte hypertrophy. To generate hypertrophy of cardiac myocytes, neonatal rat cardiac myocytes were subjected to exogenous hypertrophic agonists such as endothelin-1 (ET-1) or to cyclic mechanical stretch. The role and regulation of transcription factors were studied by utilizing promoter analysis together with site-specific mutations and measurement of DNA binding activity and phosphorylation. GATA-4 mediated signaling was inhibited by blocking DNA binding with decoy oligonucleotides or by decreasing GATA-4 synthesis via adenoviral antisense delivery. ET-1 activated GATA-4 via serine residue phosphorylation, and this effect was mediated via p38 kinase. Similarly, GATA-4 binding activity was increased by ET-1 and mechanical stretch, but it was essential for activation of BNP gene only in the latter stimulation. Importantly, downregulation of GATA-4 protein levels prevented mechanical stretch induced hypertrophy of cardiac myocytes. In contrast, separate mechanism for an ET-1 specific signaling was composed of p38 kinase regulated ETS-like transcription factor-1 (Elk-1). Finally, the effect of mechanical stretch on endogenous endothelin-1 (ET-1) synthesis in cardiac cells was studied. Intrinsic ET-1 synthesis was activated in stretched cardiac myocytes, yet the levels of ET-1 were relatively low. This work suggests that GATA-4 transcription factor is required for mechanical stretch mediated hypertrophic program, and Elk-1 may act as a downstream effector of ET-1 in cardiac myocytes. Taken together, induction of ET-1 and BNP genes as well as activation of GATA-4 and Elk-1 transcription factors are regulated via a network of mitogen activated protein kinase pathways.

Abstract Cardiac hypertrophy provides an adaptive mechanism to maintain cardiac output in response to increased workload, and although initially beneficial, hypertrophy eventually leads to heart failure, a major cause of morbidity and mortality in Western countries. The hypertrophic response in cardiac myocytes is accompanied by e.g. activation of signal transduction pathways, such as mitogen-activated protein kinases (MAPKs), and complex changes in gene programming. The purpose of this study was to characterize gene expression patterns in experimental models of cardiac load by using high-throughput DNA microarray technologies. In the present study, changes in gene expression were evaluated in response to acute pressure overload and prolonged hypertension as well as during the development of left ventricular hypertrophy (LVH) and the transition to diastolic heart failure in an animal model of genetic hypertension, the spontaneously hypertensive rat (SHR). Increased expression of several immediate early genes was seen in response to acute hemodynamic overload in vivo. The transition from LVH to diastolic hypertensive heart failure was almost exclusively associated with changes in genes encoding extracellular matrix proteins and their regulatory processes showing the importance of progressive extracellular matrix remodeling. The effect of p38 MAPK activation on gene expression patterns in vivo was elucidated. Cardiac-specific overexpression of p38 MAPK resulted in upregulation of genes controlling cell division and inflammation as well as cell signaling and adhesion. Accordingly, the functional role of p38 MAPK was related to myocardial cell proliferation, inflammation and fibrosis. Finally, temporal analysis of mechanical stretch induced gene expression changes in neonatal rat cardiomyocyte cultures in vitro indicated that mechanical stretch induced complex gene expression profiles, demonstrating that both positive and negative regulators are involved in the hypertrophic process. Many novel stretch responsive genes were identified, and a subset of them may be putative downstream targets of p38 MAPK. In conclusion, in the present study a number of well-established gene expression changes of cardiac hypertrophy were observed and novel modulators associated with increased cardiac load, such as thrombospondin-4, were identified. The study provides a better understanding of molecular mechanisms associated with increased cardiac load, and may indicate potential targets for novel therapeutic interventions.

Plyometric training has always been a topic of interest in terms of sport perfor-mance enhancement and development. The most relevant and up-to-date data has been reviewed to try to answer the question “what kind of plyometric training to use” to improve ones’ performance. The present study demonstrates the use of re-active strength index (RSI) and force-velocity profiling. In the text there is also a presentations of common jumping tests that help practitioners to establish a profile of an athlete. Main findings of this study are: general strength should be developed alongside reactive strength qualities, plyometric training optimized and guided by RSI is highly effective in improving reactive strength ability, demands of a sport determine the manner in which plyometric exercises should be performed, RSI can be used as a representation of neuromuscular fatigue, force-velocity (F-v) approach may help improve the training practice for performance in explosive push-off ac-tions like jumping, through a more efficient monitoring and understanding of the individual determinants of athletic performance, showing the sensitivity of the F-v profile to specific training programs can result in either maximal force or velocity capabilities improvements (determination of F-v imbalances or FVimb) – which is termed “optimized training” and it has been found that an optimized and individu-alized training program specifically addressing the FVimb is more efficient for im-proving jumping performance than traditional resistance training.

In the investigation of the Diary and its validity as evidence, the origin and structure of the treaty System, and the functioning of the treaties, in both their original form and subsequent modification, has been examined, with special reference to Stretch and the Gaika tribes.

Dampening systems are important in heavy vehicles utilized in rough terrains, with purpose to reduce shocks and vibrations with negative influences on the vehicle and, more importantly, on the operator of the vehicle. During the years the heavy vehicles require sturdier construction parts, due to demands on higher load capacity, where the easy solution to scale up the construction parts is not always applicable for dampening systems with nonlinear behavior. Hence, the sturdiness in the design of these dampening systems requires improvement. In this thesis the design of the rubber spring used as rubber spring in Volvo’s articulated hauler A40G is treated. The aim of this thesis is to find alternative design solutions on the rubber spring, improving its lifetime. The usual failure of these rubber springs is crack propagation in the rubber body. In the method of this thesis, alternative design solution are generated in concepts though brain storming, which are adjusted to achieve the desired behavior of the rubber spring through calculations and tested in performance through simulations in Abaqus. From analyzing the generated data, it is concluded that among the tested design solutions, a combination of fewer plates and shaping the plates as thin bowls, results in highest potential increase in lifetime.

M.Tech. / Striae are linear scars in the dermis which arise from rapid stretching of the skin over weakened connective tissue (de Angelis & Adatto, 2010). Striae occur when collagen production cannot keep pace with a sudden growth of the underlying tissues. Striae have no medical consequences but are frequently distressing to those afflicted. These disfiguring marks are usually caused by excessive stretching of the skin that may occur with pregnancy, adolescent growth spurts, obesity and weightlifting (Kang & Arbor, 1998). Striae usually appear on the abdomen, thighs, buttocks, breasts and extremities. Patients’ quality of life can be enhanced with the effective management of these unsightly marks. Modalities of treatments that exist for the treatment of striae have been advocated with varying success and side effects (Manuskiatti et al., 2010). The aim of this study was to determine the efficacy of the topical application of a homoeopathic preparation Thiosinaminum 1X on the appearance of striae. The research was a double-blind placebo controlled study which took place at the Homoeopathy Health Centre which is located at the University of Johannesburg(Doornfontein campus). Forty female participants aged between eighteen and thirty-five were randomly selected to take place in the study. The study was conducted over a period of twelve weeks. On recruitment, the participants were required to read and sign the information sheet (Appendix A) and consent form (Appendix B) assisted by the researcher. Participants were asked to complete a questionnaire (Appendix C) to determine contributing factors e.g. duration of the stretch marks, the cause of the stretch marks and any disease that may contribute to the formation of stretch marks. A pertinent case and vital signs were taken at the initial consultation to eliminate any pathologies. All potential participants were required to present with stretch marks on the thighs or buttocks present for at least 6 months prior to the study. The stretch marks needed to have had a minimum length of 50mm and a maximum length of a 100mm. The researcher was responsible for choosing the designated area that was treated. The most distinct striae were selected by the researcher according to criteria for treatment. The researcher took photographs of the treatment areas at the commencement of the study and this was repeated at the end of the study (Appendix I). The length of the most prominent stretch mark (according to criteria) below was also measured on the commencement of the study. To physically iv measure the most prominent stretch mark a string and a ruler was utilized. The same ruler and ball of string was used each time to ensure validity of the results. A new piece of string was cut and tied in a knot at the tip and placed on the stretch mark itself to mould to its shape and thereafter it was placed on a ruler to determine the measurements in millimeters. To ensure that the same stretch mark was measured every time, the researcher measured out the distance between the stretch mark and a defined anatomical point for all the participants. The stretch mark was traced using plotting paper. The participants were required to apply the cream twice daily for the duration of the study. Participants were able to rate their satisfaction on a monthly basis by completing a questionnaire. The results of the study indicated that there was no improvement in the length of striae however there was more improvement in satisfaction ratings throughout the study from the experimental group.

No description available.