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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.
311

Bachelor of Clinical Medical Practice (Clinical Associate ) student reflections during clinical rotations

Gibbs, Audrey January 2014 (has links)
Background: The BCMP degree (Clinical Associates) was introduced in South Africa in 2008 and at the University of the Witwatersrand in 2009. This first cohort of students produced challenges and questions around teaching and the learning environment. The clinical experience was mainly in district and regional hospitals, not tertiary academic hospitals, with clinical learning supervised by staff at these hospitals. Faculty therefore relied on student portfolios to ascertain learning and experiences in the clinical setting. This included reflective journals. Aim: To identify the issues that third year BCMP students in the clinical areas choose to write about in their reflective journals. Methods: The journals of 24 BCMP students written during the first two clinical rotations of their final (third) year were included in a retrospective study. Thematic content analysis of these journals was employed to examine emerging themes and subthemes. Each student’s narrative pieces were then further analysed in detail. Many of the journal entries contained more than one reflection and each of these reflections was analysed and the relevant themes and subthemes were identified. Results: The reflections show that students focused on staff and health care systems issues, especially resources, attitudes and work ethic. The majority of these staff and health care related reflections were negative but positive experiences and role models were also identified. There were differences noted between hospitals and rotations, with the paediatric rotation showing the most positive responses, and the emergency rotation the least. Conclusion: The students identified lapses in the health services and health providers which affected patient care. They also recognised positive experiences and role models. This reveals a mismatch between teaching and their clinical experience. These experiences will be used to advise future teaching and research, as well as to provide feedback to the hospitals used for clinical training. Discussions should be held as to ways of reporting these incidents and improving professional standards in the clinical teaching settings.
312

Thermal Sensitivity of Calcium and Magnesium Binding for Parvalbumins from Teleost Fish

Unknown Date (has links)
Parvalbumin is an abundant divalent cation binding protein of fast vertebrate skeletal muscle. Its proposed function is to sequester calcium after contraction, thus facilitating relaxation. Calcium and magnesium equilibrium dissociation constants and instantaneous rate constants of parvalbumins from two Antarctic teleosts (Gobionotothen gibberifrons and Chaenocephalus aceratus), two temperate zone teleosts (Cyprinus carpio and Micropterus salmoides), and one Arctic teleost (Boreogadus saida) were determined to assess potential differences in protein function. PV was isolated by homogenization followed by gel filtration and ion exchange chromatography. Sample purity was checked by 2-D PAGE. Dissociation constants were determined by a competitive binding assay between parvalbumin and either fluo-3 or Magnesium Green. Thermodynamic parameters were determined by calorimetry. Instantaneous rate constants were determined by stopped-flow spectrometry. Deduced amino acid sequences were also determined for several teleost parvalbumins. Functional data showed that parvalbumins from different teleost fish can exhibit markedly different patterns of thermal sensitivity. However, a general pattern of conservation for several binding parameters at native temperature was observed. Sequence data indicated that the major structural features, including the coordinating residues of the binding loops, were conserved in parvalbumins. Substitutions leading to variability of thermal function are likely to have occurred outside the binding loops of the protein. / A Dissertation submitted to the Department of Biological Science in partial fulfillment of the requirements for the degree of Doctor of Philosophy. / Degree Awarded: Fall Semester, 2005. / Date of Defense: September 19, 2005. / Parvalbumin, Muscle, Temperature / Includes bibliographical references. / Timothy S. Moerland, Professor Directing Dissertation; Timothy M. Logan, Outside Committee Member; P. Bryant Chase, Committee Member; W. Ross Ellington, Committee Member; Betty J. Gaffney, Committee Member.
313

ROLE OF PROTEINASES IN CELLULAR INVASION AND METASTASIS OF L1210 AND L5178Y MURINE LEUKEMIAS

Unknown Date (has links)
The proteinase activities of the L1210 and L5178Y murine lymphocytic leukemias have been measured and characterized in order to determine whether a correlation exists between proteinase activity and metastatic potential. Such a correlation would be expected if proteinases promote invasion and metastasis by degrading host tissue. These lines were chosen for study because they are very similar in most respects, but differ dramatically in their ability to metastasize. The kinetics of tumor cell proliferation, death, and metastasis for these lines are the best currently available. / Tumor cell suspensions and supernatants were assayed for activity against basement membrane, elastin, Type I collagen, hemoglobin, casein, benzoyl-Arg-napthylamide, and N-acetyl-(Ala)(,3)-p-nitroanilide. Since no quantitative assay for the hydrolysis of intact basement membranes existed prior to these studies, a sensitive new one based on the hydrolysis of bovine lens capsule membranes has been developed. Significant levels of proteinase activities were detected in suspensions of both tumor lines against all the substrates tested, and it is clear that the spectrum of activities found is capable of facilitating metastasis. Two membrane-associated proteinases have been found in both tumor lines, one active against both basement membranes and benzoyl-Arg-napthylamide and the other against N-acetyl-(Ala)(,3)-p-nitroanilide. Host cells were primarily responsible for the hydrolysis of the other substrates, although there was some cathepsin D activity attributable to tumor cell death. / No significant differences in proteinase activity levels were detected between the two lines. hence, while these proteinase activities may assist in the metastasis of these two cell lines, some other factor must also be involved. The ability of the two tumor lines to bind to intact basement membranes was examined and no differences in binding capacity were detected. Thus, some other additional factor, such as the capacity for directional motility, is probably involved. / Source: Dissertation Abstracts International, Volume: 45-06, Section: B, page: 1662. / Thesis (Ph.D.)--The Florida State University, 1984.
314

PURIFICATION OF HUMAN ANGIOTENSIN I CONVERTING ENZYME (KININASE II) CHARACTERISTICS OF THE LUNG AND KIDNEY ENZYMES

Unknown Date (has links)
Source: Dissertation Abstracts International, Volume: 41-09, Section: B, page: 3289. / Thesis (Ph.D.)--The Florida State University, 1980.
315

Cytocidal and radiosensitizing properties of two newly developed nitroimidazole drugs: Ro 03-8799 and RSU-1164

Unknown Date (has links)
The cytocidal and radiosensitizing effects of two newly developed 2-nitroimidazole derivatives (Ro 03-8799 and RSU-1164) were evaluated with the original compound, misonidazole, serving as a reference agent. More specifically, euoxic and hypoxic BP-8 murine sarcoma cells were exposed for up to 3 hours to various concentrations of the three nitroimidazole derivatives, with or without irradiation, and the resulting cell lethality was monitored with the $\sp{125}$IUdR prelabeling assay. When cell death was evaluated as a function of drug molarity, the three nitroimidazoles displayed widely different toxicities, but when expressed in terms of toxicity ratio between euoxic and hypoxic cells, all three drugs showed nearly identical toxicity differentials of 16 to 18 in 1 hour drug incubation experiments. Prolonging the treatment period to 3 hours with RSU-1164, the toxicity ratio was increased significantly from 16 to 73. This increase was attributed to the bifunctional action of RSU-1164 as a combined electron-affinic and alkylating agent, with the alkylation component of hypoxic cell killing becoming more pronounced after prolonged drug incubation. Combined administration of hyperthermia and nitroimidazoles increased drug-induced cell lethality for all three agents, but did not materially change the relative toxicity differential between euoxic and hypoxic cells. / The radiosensitizing effects of the three compounds were studied at sublethal drug doses, with the drug concentrations adjusted to provide equitoxic (isosurvival)treatment conditions. Under thse experimental conditions, all three drugs displayed equal radiosensitizing effects in short term drug exposures which measure mainly the so-called "oxygen-mimetic" component of radiosensitization. However, with longer drug incubation periods a second component of sensitization known as "preincubation effect" or "damage interaction" became apparent. The magnitude of this damage interaction effect at equitoxic doses for RSU-1164 produced significantly higher damage interaction than the other two agents. / In conclusion, based on cellular toxicity and radiosensitization data, Ro 03-8799 appears to offer no advantage over misonidazole as a selective cytocidal and radiosensitizing agent for hypoxic cells, but RSU-1164 does provide a moderate therapeutic advantage. Additional factors operating in intact animals could further enhance the potential of RSU-1164 and could also serve to make Ro 03-8799 more effective than misonidazole as an adjuvant to chemotherapy and radiotherapy of cancers. (Abstract shortened with permission of author.) / Source: Dissertation Abstracts International, Volume: 49-10, Section: B, page: 4126. / Major Professor: Kurt G. Holer. / Thesis (Ph.D.)--The Florida State University, 1988.
316

DNA SUBUNITS OF MAMMALIAN CHROMOSOMES

Unknown Date (has links)
Source: Dissertation Abstracts International, Volume: 36-12, Section: B, page: 5935. / Thesis (Ph.D.)--The Florida State University, 1975.
317

Diffusion kurtosis imaging (DKI) in the human calf muscles

Lindquist, Mirabelle 17 February 2016 (has links)
Human calf muscle injuries are relatively common among individuals from various backgrounds. Miniscule tears in the muscles of the calf such as the medial gastrocnemius, lateral gastrocnemius, and soleus, may be difficult to identify using traditional imaging modalities. Diffusion kurtosis imaging (DKI), is one type of diffusion imaging that has presented with some strengths over diffusion tensor imaging (DTI) and diffusion weighted imaging (DWI). Though DTI studies in the human calf have been published, no DKI studies in the human calf exist to our knowledge. The objective of this study is to determine whether or not DKI is applicable in identifying quantitative changes between states of dorsiflexion and relaxation in the human calf. One female participant underwent DKI. Data from the scanning was quantitatively analyzed via the use of FSLView and the NODDI MATLAB toolbox. A change in mean voxel intensity in the calf and mean orientation dispersion index was identified in each of the five slices analyzed, in each muscle group (medial gastrocnemius, lateral gastrocnemius, and soleus). Most of the changes, whether an increase or decrease in mean value—between the states of dorsiflexion and relaxation—were statistically significant. We conclude that DKI may have a future in identifying physical/quantitative changes in calf muscles between the tense/relaxed states. Further studies using DKI on the human calf should be conducted in the future and address the limitations of the current study. Further investigation could possibly benefit individuals with miniscule calf muscle injuries.
318

Relationship between primary liver hepatocellular carcinoma volumes on portal-venous phase CT imaging

Aisaborhale, Ehimen Edward 12 March 2016 (has links)
The liver is an important organ in the body. It is located under the rib cage on the right side. The liver performs many important functions, it processes food for nutrients that the body requires and also helps in the detoxification of harmful materials. Like any organ in the body, the liver is susceptible to diseases such as liver cancer. Liver cancer is the growth and spread of unhealthy cells of the liver. There are several risk factor for liver cancer, these are: Cirrhosis (scarring of the liver), long term hepatitis B and hepatitis C infection and diabetes patients with long term drinking problem. Hepatocellular Carcinoma is the most common form of liver cancer in adult population which begins in the main type of liver cell (hepatocyte). Because Hepatocellular carcinoma starts from the primary liver cell itself (hepatocytes), as such it is a primary liver cancer. About 30,000 Americans are diagnosed with primary liver cancer yearly, making it an important disease that plaques our society and therefore needs proper diagnosis. In clinical evaluation of primary liver cancer such as HCC, the use of medical imaging technology has been commonplace. Most medical facilities across the country and globally typically use Computed Tomography (CT) and/or Magnetic Resonance Imaging (MRI) in the diagnosis and treatment follow up of Hepatocellular carcinoma. The medical imaging devices are used to determine the extent and volume of the tumor of the cancerous liver cells. In clinical trials involving the imaging of HCC tumors, the typical protocol used in the CT imaging of HCC involves the use of contrast enhanced dual phase acquisition. This approach is based on the physiology of the blood flow through the liver. Since HCC tumors are hypervascular in nature, it would thus be more apparent in the arterial phase of an acquired CT image. The aforementioned characteristic was tested with a volume paradigm which measure and compare the volume of both the arterial phase and portal venous phase acquired images in the experiment. Overall this study helps in furthering goals to reduce the patient dose from the x-ray tubes during clinical trials. The results of the experiments (n = 19, t = 0.67, p = 0.26), indicates no significant difference between the volume of the HCC tumor images acquired both in the AP and PVP.
319

Multiparametric 3 Tesla magnetic resonance imaging as a clinical tool to characterize prostate cancer

Dunn, Matthew Christopher 12 March 2016 (has links)
Scientists have come a long way in understanding prostate cancer as a disease and how its progression affects the men who develop it. Prostate adenocarcinoma may be present without causing clinical symptoms. Prostate cancer may metastasize, which increases the likelihood of fatality. The cause of the disease is still not completely clear, but genetics, race, tissue damage, history of previous infections, diet, and environmental influences appear to play a role in its development. Magnetic resonance imaging (MRI) has become an excellent clinical tool to characterize prostate cancer without the use of ionizing radiation or surgery. It is concluded that MRI is the optimal imaging modality to achieve detection, characterization, and staging of intracapsular and extracapsular prostate disease. The advances in MRI technology, particularly 3 Tesla, allows for reduced surgical intervention thus improving quality of life for patients with the disease.
320

Optic nerve atrophy: a comparison of two imaging modalities to evaluate their sensitivity for diagnostic purposes

Cheng, Anh-Dao M. 12 July 2017 (has links)
PURPOSE: To evaluate the efficacy of MRI as a diagnostic tool by comparing it to OCT in patients with suspected optic nerve atrophy. Currently, MRI is an established noninvasive imaging modality for tumors and inflammatory tissues; however their use in optic nerve atrophy is limited to advanced cases. Our study investigates the use of OCT, a more sensitive imaging modality, compared to MRI as a potential adjunct to the clinical diagnosis of optic nerve atrophy. METHODS: This retrospective study analyzed 27 medical records (40 eyes) of patients with suspected optic nerve atrophy referred to the Neuro-ophthalmology Clinic of the Beth Israel Deaconess Medical Center (2009-2016) who had both MR imaging of the orbits and SD-OCT scans. Based on the RNFL thickness obtained from OCT scans, optic atrophy was defined as border, mild, moderate, or severe. MRIs were used to measure the optic nerve area, optic nerve diameter and sheath area of all eyes. From there, the ratio of optic nerve area to sheath area, percent difference in optic nerve diameters in a patient and percent difference in optic nerve areas in a patient were determined. RESULTS: As atrophy worsens, the optic nerve area and sheath area seem to steadily decline. The ratio between the two seems to remain constant (0.27) regardless of degree of atrophy. Focusing on unilateral patients, the percent difference in optic nerve area with mild optic atrophy seemed minimal (14%). It becomes more significant in moderate and severe atrophy cases (56.06% and 26.18% respectively). Overall, there does not seem to be a strong correlation between MRI measurements and OCT RNFL values. CONCLUSIONS: Overall, a strong correlation was not found between MRI measurements and OCT RNFL thickness values. While a general trend existed, there was too much variation to determine cut off points for atrophy based solely on the measurement of a single eye. MRI may be useful in identifying severe and moderate optic nerve atrophy especially in unilateral patients. Once the RNFL thins to about 70 μm, the difference in size is detectable on MRI. For all cases of mild optic atrophy and bilateral moderate atrophy, OCT remains a more reliable imaging diagnostic. Changes in nerve size appear minimal compared to a healthy human. The optic nerve sheath was also shown to decrease in size in cases of atrophy. Future studies with a larger sample size are needed to produce more conclusive results.

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