A dissertation in partial compliance with the requirements for a Master's Degree in Technology in the Department of Chiropractic at Technikon Natal / Cavitation sounds heard during chiropractic adjustments and manipulations to th extension spine are a common phenomena yet their significance is disputed, the mechanism of their production is a matter of speculation, and their origin has never been localized. (Lewit 1978: 4, Grieve 1989; 525) The purpose of this study was to locate the joints which cavitate during the performance of a L5 spinous hook adjustment and a lower sacroiliac adjustment. It was hypothesised that the cavitation sounds would arise from the L4-L5 and L5-S1facets on the side of contact during the L5 hook adjustment., and from the the sacroiliac joint on the side being adjusted during the lower sacroiliac adjustment. It was also hypothesised that the two adjustments would differ significantly in terms of the cavitation sounds produced. Volunteers were screened for agreement with the inclusion criteria. Of these 30 asymptomatic between the ages of 18 and 30 were selected. This was sample was then randomly divided into two groups of, one of which recieved the L5 hook adjustment and the other the lower sacroiliac adjustment. All of the subjects had eight microphones taped to the skin, over the relevant facets and the sacroiliac joints. Radiographic confirmation was used in order to ensure proper positioning of the microphones. The microphones were then connected to filters, amplifiers and a computer which recorded any sound signals registered during the adjustments. / M

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Targeted intracellular delivery is a goal of many novel drug delivery systems to treat site-specific diseases thereby increasing the effectiveness of drugs and reducing side effects associated with current drug administration. The development of ultrasound-enhanced delivery is aimed at providing a targeted means to deliver drugs and genes intracellularly by utilizing ultrasound s ability to non-invasively focus energy into the body and generate cavitation, which has been found to cause transient poration of cells. To address some of the current issues in this field, the goals of this study were (i) to develop a measurement of cavitation to correlate with cellular bioeffects and (ii) to evaluate the ability of ultrasound to target delivery into cells in viable tissue. In addition, this study sought to exploit the shear-based mechanism of cavitation by (iii) developing a simplified device to expose cells to shear stress and cause intracellular uptake of molecules. This study has shown that broadband noise levels of frequency spectra processed from cavitation sound emissions can be used to quantify the kinetic activity of cavitation and provide a unifying parameter to correlate with the cellular bioeffects. We further demonstrated that ultrasound can target delivery of molecules into endothelial and smooth muscle cells in viable arterial tissue and determined approximate acoustic energies relevant to drug delivery applications. Lastly, we developed a novel device to expose cells to high-magnitude shear stress for short durations by using microfluidics and demonstrated the ability of this method to cause delivery of small and macromolecules into cells. In conclusion, this work has advanced the field of ultrasound-enhanced delivery in two major areas: (i) developing a real-time non-invasive measurement to correlate with intracellular uptake and viability that can be used as means to predict and control bioeffects in the lab and potentially the clinic and (ii) quantitatively evaluating the intracellular uptake into viable cells in tissue due to ultrasound that suggest applications to treat cardiovascular diseases and dysfunctions. Finally, by using shear forces generated in microchannels, we have fabricated a simple and inexpensive device to cause intracellular uptake of small and large molecules, which may have applications in biotechnology.