Bacteria are implicated in endodontic infections. They not only infect the root canal lumen but also invade the dentinal tubules where they may remain untouched by contemporary chemomechanical preparation during root canal therapy. The contentious issue is whether the bacteria within these tubules contribute to secondary infections. Many studies have shown that clinicians fail to completely eradicate them during root canal therapy. At present there are no techniques available to detect the effectiveness of the current chemomechanical treatment regime within dentinal tubules. It is difficult to detect bacteria within the dentinal tubules. Culturing techniques have been used routinely as they are versatile and easy to use. However, they are unable to show the distribution of the bacteria within the dentinal tubules. Scanning electron microscopy, on the other hand, shows detailed surface structure in association with bacteria. Histological examination of root dentine specimens under the light microscope also shows the distribution of bacteria within the specimen but not viability. The dilemma posed by these existing techniques is that the results offer limited information; either demonstrating bacterial viability or bacterial distribution within specimens. No techniques able to show both the viability and the distribution of bacteria within the dentinal tubules have been reported to date. Fluorescent stains, in particular SYTO�9 and propidium iodide (LIVE/DEAD� Baclight[TM] viability kit, Molecular Probes Inc., Eugene, Oregon), have made it possible not only to stain bacteria but to differentiate live and dead bacteria. The combination of these two stains has yet to be applied to dental hard tissue in situ and they provide the basis for this investigation. The aim of this study was to evaluate the potential of the LIVE/DEAD� Baclight[TM] stains in conjuction with confocal laser scanning microscopy in the development of a technique to evaluate the viability and distribution of bacteria within dentinal tubules. This was extended to demonstrate the application of this technique by examining three different means of root canal disinfection both qualitatively and quantitatively. An important aspect of this study was to maintain bacterial viability, as well as to get maximum bacterial invasion into dentinal tubules. Results indicated that when the root canals were instrumented with Protaper� files and then irrigated with sodium hypochlorite (NaOCl) and ethylene diaminetetraacetic acid with cetrimide (EDTAC), there was more bacterial invasion into the dentinal tubules than when the root canals were only irrigated with NaOCl and EDTAC. Daily replenishments of nutrients resulted in deeper bacterial invasion into the dentinal tubules. Bacteria colonized the dentinal tubules up to a distance of 594 � 133 [mu]m from the canal. In the untreated tubules, 96 � 4 % of bacteria remained viable (green-fluorescent), whereas the Amoxicillin-treated tubules contained 94 � 6 % dead (red-fluorescent) bacteria. The calcium hydroxide-treated tubules resulted in 92 � 7 % bacterial death while the laser-treated tubules contained 81 � 12 % dead cells, frequently displaying an inner zone of dead cells surrounded by an outer zone of viable cells. The application of the fluorescent stains combined with confocal microscopy offers a new method for assessing the in vitro efficacy of root canal disinfection regimens.

The main strategy for treating solid cancers is based on the very early diagnosis of a malignant tumor, and in general the smaller the tumor, the greater the likelihood of successful treatment. Magnetic Resonance Imaging (MRI), based on the nuclear magnetic resonance phenomenon, provides the possibility of detecting early malignant tumors with the assistance of appropriate contrast agents. Hence, researchers continue to develop novel magnetic materials to achieve this aim. Superparamagnetic nanoparticles have become the focus of these studies because their superparamagnetic, biocompatible and hydrophilic properties would be revealed after modifying the particle surface by suitable surfactants. Considerable research in this area has provided valuable insights; however, suitable magnetic materials that can fulfill all the requirements of MRI application are still under investigation. Surface modification of superparamagnetic nanoparticles towards their use as MRI contrast agents has been the topic for many researchers, but implementation into fully functional in vivo procedures still remains as a challenging task. In the present study, high quality monocrystalline iron oxide nanoparticles have been synthesised and surface-modified with carboxymethylated dextran as well as polyethylene glycol (PEG). Dextran and PEG macromolecules with low and high carboxyl contents were synthesized and grafted onto dopamine-iron oxide nanoparticles. Furthermore, the coating procedure was optimised to prevent aggregation among the nanoparticles. Dextran-coated and PEG-coated nanostructures were characterised by using X- ray Photoelectron Spectroscopy (XPS), Fourier Transformer Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS). Consequently, mono-dispersed dextran coated nanoparticles were obtained with an approximate hydrodynamic diameter of 50 nm. The resulting coated nanoparticles exhibited the nanostructures with an excellent colloidal stability in physiological environment even at high salt concentration. The resistance to non-specific protein adsorption was investigated in an in vitro model. Both dextran-coated and PEG-coated nanoparticles displayed low non-specific adsorption. However, the free carboxyl groups could be activated to covalently immobilize proteins. / Thesis (M.Eng.Sc.)--School of Chemical Engineering, 2006.

The process of pulse diagnosis was examined in a sample of 100 patients randomly selected from the author's acupuncture clinic. Patient symptoms, pulses (as utilised in traditional Chinese medicine), diagnostic criteria (as described in traditional Chinese medicine), acupuncture points selected and patient comments after each treatment were coded into a numerical format suitable for stepwise multiple regression and crosstabulation analysis. The analysis indicated that the interpretation of pulse qualities predicted the diagnostic criteria when used in accordance with the theories of acupuncture. The selection of acupuncture points could not be predicted from the diagnostic criteria when using pulse diagnosis. Additionally the analysis indicated that the patient comments after acupuncture were independent of the initial patient symptoms. More research is needed to more fully understand the process of pulse diagnosis. However the analysis does suggest that pulse diagnosis should be incorporated into acupuncture curricula in both traditional acupuncture courses and medical acupuncture courses.

The diagnosis of porcine circovirus-associated disease (PCVAD) in pigs requires the detection of characteristic clinical signs and pathological changes, and the detection of virus in tissues of affected pigs. To increase Australia’s capacity to independently diagnose PCVAD in Australia, techniques for the detection of Porcine circovirus type 2 (PCV2) infection in pigs were developed and are reported in this thesis. These techniques were applied to samples obtained from normal pigs and pigs with disease and confirmed the presence of PCV2 and PCVAD in the Australian pig herd. Viral DNA was detected in tissues of infected pigs by both standard PCR and real-time PCR techniques. The real-time PCR was more sensitive. While the conventional PCR was able to detect approximately 100 copies of the viral genome, the real-time PCR was able to detect 20 copies of the genome. An immunohistochemical (IHC) technique which was also developed enabled the visualisation of PCV2 antigen in fixed tissues of pigs with PCVAD. The techniques that were developed were applied to an examination of tissues from pigs affected by illthrift and increased weaner mortality in herds in South Australia, New South Wales and Western Australia. Lesions suggestive of the PCVAD postweaning multisystemic wasting syndrome (PMWS) were detected and virus antigen was detected in association with lesions. The nature of the clinical signs and histopathological lesions detected, coupled with the presence of PCV2 antigen, suggested that PCVAD was present in some Australian pig herds. Phylogenetic analysis of the strains of PCV2-associated with these disease outbreaks demonstrated they were of a type not previously detected in Australia and similar to strains associated with PMWS in North America. To further assist in investigation of PCV2 infections in the Australian pig herd, an enzyme-linked immunosorbent assay (ELISA) was developed that specifically detected antibody to PCV2 and not the related and non-pathogenic Porcine circovirus type 1. The development of this assay required the production of a virus capsid protein antigen using a prokaryotic protein production system. The ELISA was used to test serum samples form the Australian national pig serum bank. A high prevalence of PCV2 infection was detected in most pig herds examined in all Australian states. International trade in pig meat has resulted in many countries placing restrictions on the importation of pig meat, requiring imported pig meats to be cooked to destroy viral agents. This study investigated the in vitro resistance of an Australian strain of PCV2 to heat treatment at temperatures between 56°C and 85°C. The viability of the virus was determined by a combination of reverse transcriptase polymerase chain reaction (RT-PCR), and IHC to visualise viral capsid antigen within infected cells. This study indicated that PCV2 retained its infectivity following heating up to and including 75°C for 15 mins, but was inactivated following heating to 80°C and above. The investigations reported make a significant contribution to PCV2 research in Australia and ensure Australia’s capacity to independently investigate PCVAD in the Australian pig herd.

Includes bibliographical references (leaves 194-225) / ix, 225, vii leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / A new method is described that enables longitudinal and cross sections of an individual nerve fibre to be cut at multiple specified sites along the fibre by use of an unique marker system. The method is particularly useful for the correlative study of myelin-axon relationships / Thesis (Ph.D.)--University of Adelaide, Dept. of Medicine, 2002?

The 16 publications presented in this thesis summarise the author’s contribution to seroepidemiological approaches for the diagnosis and monitoring of animal diseases of importance to New Zealand. The first four publications not only contribute to the above in relation to three important animal pathogens, namely Brucella ovis, Mycobacterium avium spp. paratuberculosis and Bovine Leukaemia Virus but also give an insight into more general consideration associated with the optimisation and validation of serological assays, namely regarding the definition and choice of gold standard reference sera, the determination of the cutoff threshold and discrimination between negative and positive reference populations. Two further publications deal with the establishment and validation of serological assays for the diagnosis of Neospora caninum infection and abortion in New Zealand. Then, baseline data were obtained for the sero-prevalence of the infection in dog and cattle populations in New Zealand. Three case studies provided initially information about the kinetics of serological responses after a N caninum abortion outbreak, and information about the usefulness of herd-based techniques rather than individual cowbased abortion diagnoses. A further study provided some early information about the mode of transmission seemingly predominating in New Zealand, which tends to be mainly via post-natal infection, in contrast to evidence provided by overseas researchers. A final case study, a longitudinal study of serological and other responses over a period of three years also provided data on the production effects of N caninum. The dissertation is completed by a number of reviews on sero-diagnosis of N caninum infection, its presence in Australasia and suggests finally control options, based on the present state of knowledge.

Thesis (Ph.D.)--McMaster University, 2006. / Supervisor: Lee R. Brooks and Geoffrey R. Norman. Includes bibliographical references (leaves 81-90). Mode of access: World Wide Web.

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

The 16 publications presented in this thesis summarise the author’s contribution to seroepidemiological approaches for the diagnosis and monitoring of animal diseases of importance to New Zealand. The first four publications not only contribute to the above in relation to three important animal pathogens, namely Brucella ovis, Mycobacterium avium spp. paratuberculosis and Bovine Leukaemia Virus but also give an insight into more general consideration associated with the optimisation and validation of serological assays, namely regarding the definition and choice of gold standard reference sera, the determination of the cutoff threshold and discrimination between negative and positive reference populations. Two further publications deal with the establishment and validation of serological assays for the diagnosis of Neospora caninum infection and abortion in New Zealand. Then, baseline data were obtained for the sero-prevalence of the infection in dog and cattle populations in New Zealand. Three case studies provided initially information about the kinetics of serological responses after a N caninum abortion outbreak, and information about the usefulness of herd-based techniques rather than individual cowbased abortion diagnoses. A further study provided some early information about the mode of transmission seemingly predominating in New Zealand, which tends to be mainly via post-natal infection, in contrast to evidence provided by overseas researchers. A final case study, a longitudinal study of serological and other responses over a period of three years also provided data on the production effects of N caninum. The dissertation is completed by a number of reviews on sero-diagnosis of N caninum infection, its presence in Australasia and suggests finally control options, based on the present state of knowledge.

The 16 publications presented in this thesis summarise the author’s contribution to seroepidemiological approaches for the diagnosis and monitoring of animal diseases of importance to New Zealand. The first four publications not only contribute to the above in relation to three important animal pathogens, namely Brucella ovis, Mycobacterium avium spp. paratuberculosis and Bovine Leukaemia Virus but also give an insight into more general consideration associated with the optimisation and validation of serological assays, namely regarding the definition and choice of gold standard reference sera, the determination of the cutoff threshold and discrimination between negative and positive reference populations. Two further publications deal with the establishment and validation of serological assays for the diagnosis of Neospora caninum infection and abortion in New Zealand. Then, baseline data were obtained for the sero-prevalence of the infection in dog and cattle populations in New Zealand. Three case studies provided initially information about the kinetics of serological responses after a N caninum abortion outbreak, and information about the usefulness of herd-based techniques rather than individual cowbased abortion diagnoses. A further study provided some early information about the mode of transmission seemingly predominating in New Zealand, which tends to be mainly via post-natal infection, in contrast to evidence provided by overseas researchers. A final case study, a longitudinal study of serological and other responses over a period of three years also provided data on the production effects of N caninum. The dissertation is completed by a number of reviews on sero-diagnosis of N caninum infection, its presence in Australasia and suggests finally control options, based on the present state of knowledge.