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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.
101

INVESTIGATION OF A FACTOR RELEASED BY NEOPLASTIC CELLS WHICH PRODUCES A CHEMOKINETIC RESPONSE IN ACTIVATED MACROPHAGES

Lane, Richard Durelle 01 January 1980 (has links)
The increase in rate of random migration (chemokinesis) of C. parvum activated macrophages in media conditioned by Lewis Lung (LL) carcinoma cells was attributed to a trypsin sensitive, heat stable, high molecular weight factor released from the membrane of the tumor cells. A capillary tube assay was developed to expediently monitor the chemokinetic activity of macrophages incubated in whole and fractionated media. The capillary tube assay was found to be capable of detecting both chemokinetic and chemotactic (directional movement) factors present in the test media. Statistical analysis revealed the capillary tube assay provided reproducible data both within and between experiments. Media conditioned by 6 different syngeneic and allogeneic mouse tumor cell lines demonstrated significantly higher chemokinetic activity compared to unconditioned or normal fibroblast conditioned media. The release of the chemokinetic factor (CKF) by Lewis Lung cultures was demonstrated to be maximum during the logarithmic growth phase of these neoplastic cells. Molecular seive chromatography of the Lewis Lung conditioned media revealed the CKF to have a molecular weight of approximately 360,000 daltons. Similarly to the C. parvum activated macrophages, the pyran activated macrophages responded chemokinetically to LL conditioned media. However oyster glycogen and thioglycolate elicited macrophages demonstrated no significant chemokinetic response in the presence of the LL-CKF. The Lewis Lung chemokinetic factor demonstrated no chemotactic activity in the Boyden chamber assay. In fact, the CKF actually inhibited the response of these macrophages to a known chemotactic factor. Indirect immunofluorescent staining of the CKF indicated that it was a membrane protein shed by the LL cells and bound by activated macrophages. The possibility is discussed that CKF may be a glycocalyx protein shed by tumor cells which interferes with macrophage- neoplastic cell interactions involved in the tumoricidal activity of macrophages.
102

The seminal vesicles : anatomy, comparative anatomy and development.

Retief, Peter John Mitford 16 April 2020 (has links)
There are many reasons which induced me to choose this subject for a thesis. I would like to mentioned only the most important one. Between 1942 and 1945, while in the South African Medical Corps, I was posted to the Wynberg Military Hospital. During this time I was closely associated with the urological service of the hospital.
103

A statistical shape analysis of the neurocranium and long bones

Maass, Petra January 2016 (has links)
Morphological variation of skeletal elements, and the potential use of such variation in distinguishing among demographic groups, is often investigated using traditional metric or non-metric assessments. Traditional approaches, however, often fail to sufficiently capture the "true" shape of features, thus also failing to identify potentially important feature characteristics. The development of geometric morphometrics has allowed more comprehensive and accurate three-dimensional data capture which maintains the geometric properties of an object while isolating the effect of size from the data. The aim of this study was to employ the geometric morphometric approach to a 3D digitized sample of 1132 South African individuals from the skeletal collections of the Universities of Cape Town, Stellenbosch, Witwatersrand and Pretoria. Morphological variation among demographic groups was assessed using Generalized Procrustes Analyses applied to the individual bones of the neurocranium and the long bones of the limbs. The ability to distinguish groups based on the detected variation was assessed using Discriminant Function Analysis. The results show that, when size is isolated from the data, only a few elements show sexual dimorphism, while all examined elements show high accuracy in distinguishing among ancestry groups (>74%). When variation is assessed using both parameters, classification accuracies of 70-83% are obtained. Comparison of the different elements shows that the best classification accuracies are based on the frontal bone (84% average) and the humerus (81% average). This study shows that the morphologies of the neurocranium and long bones vary among sex and ancestry groups. This allows assessment of how the combination of variable intrinsic and extrinsic influences can manifest on different parts of the skeleton. In a population as genetically and historically complex as that of South Africa, understanding of the impact of such influences may inform forensic assessments of skeletal material, which is especially valuable considering the high rate of violent crimes and increasing number of unidentified remains being discovered in the country.
104

An examination of the objective evaluation of student achievement in anatomy, with an enquiry into the results of cycling marking programs and confidence weighting of responses : the survey of an investigation into the results obtained over 7 years of experiment in the Department of Anatomy, University of Cape Town

Fredman, Marcus 06 April 2020 (has links)
The experiment of using multiple-choice tests in the Department of Anatomy grew from two concepts that had arisen in the consideration of the role of teaching in the department. The first was the need for an instrument to measure the comparative worth of any changes that we might wish to make in the methods of teaching. It was observed by Professor Wells in discussion (Wells - 1967) that, "Any change of teaching method is accompanied by an apparent but transient beneficial effect in terms of student performance". This has been called the Hawthorn effect and has been observed by educationists, but Professor Wells went further in I inking the beneficial effect to the enthusiasm of the teachers for the new methodology being communicated to the students who in tum became motivated towards performance.
105

Ancestral variation in mid-craniofacial morphology in a South African sample

Dinkele, Elizabeth 25 January 2019 (has links)
Ancestry estimation is a critical component of the demographic profile compiled by forensic anthropologists when unknown skeletal remains are discovered. The mid-craniofacial region is most frequently used to estimate ancestry as this region reflects the genetic and morphological ancestry of an individual. The diverse composition of the South African population makes ancestry estimation problematic, and necessitates the development of reliable, population-specific standards. This study sought to characterise variations in mid-craniofacial shape and size between South Africans of European ancestry (EA), African ancestry (AA) and Mixed ancestry (MA). Metric, nonmetric and geometric morphometric assessments were performed on 392 crania from skeletal collections in South Africa. Variations in mid-craniofacial shape and size were assessed in the orbital, nasal, zygomatic and maxillary regions in two-and three-dimensions. Univariate and multivariate statistical analyses were employed to characterise variation and estimate ancestry in AA, MA and EA individuals. Multivariate analyses suggest that tightly integrated ancestral variations in each component of the mid-craniofacial region are associated with functional, regional and developmental proximities of these regions. Specifically, AA individuals exhibited wider and shorter midfacial regions than EA individuals, who exhibited the narrowest orbital, zygomatic and nasal breadths and the longest upper facial, orbital and nasal heights. EA individuals exhibited inferiorly-angled orbits, elongated nasal apertures and anteriorly projecting nasal bridges. Rounder nasal apertures, less anteriorly projecting nasal bridges and more anteriorly projecting maxillary regions were detected in AA individuals. MA individuals exhibited heterogeneity in terms of craniofacial shape and size, and therefore produced the lowest ancestry estimation accuracies. Overall, nasal and maxillary regions were the most ancestrally diverse regions. Antemortem maxillary tooth loss and midfacial trauma were confounding factors in ancestry estimation accuracies. The lowest ancestry estimation accuracies were yielded by two-dimensional metric (27%-60.2%) and nonmetric (57.1%-82.4%) methods. Metric and geometric morphometric assessments yielded the highest repeatability (≥ 95%) indicating that these methods may be more reliable for use in medicolegal contexts. Geometric morphometric shape assessments yielded the highest ancestry estimation accuracies (75-97.9%), suggesting the presence of three dimensional shape variations between ancestry groups. These results suggest that a continuum of ancestral variation, with large areas of overlap, exists across South African populations and emphasises the need to develop multivariate ancestry estimation standards which can estimate ancestry reliably.
106

Variations in the insertions of the tibialis posterior muscle and the structure of the medial longitudinal arch

Sadler, Maxwell Jennings January 2014 (has links)
Includes bibliographical references. / This study utilized cadavers to examine the variable insertions of the tendon of tibialis posterior muscle. Both feet from 29 cadavers were dissected and six variable connections to intrinsic foot structures were documented (frequencies indicated as a per cent): sustentaculum tali (93.1%), abductor hallucis muscle (44.8%), flexor hallucis brevis muscle (22.4%), fibularis longus tendon (58.6%), plantar calcaneonavicular (spring) ligament (17.2%), and the long plantar ligament (34.5%). The frequencies for each variable insertion were also reported individually for sex and population group, as well as the most common combinations of insertions. Measurements describing the medial longitudinal arch of the feet were taken, using a soft tissue intact method (arch index) and the post-dissection method (talus-first metatarsal angle). The insertion data were then compared to the arch measurements, as well as foot side, age, sex, and population group. There was a weak negative correlation between the talus-first metatarsal angle measurement and the presence of an insertion on to sustentaculum tali, as well as a connection to the tendon of fibularis longus. Arch measurements were shown to be statistically significantly similar for left and right feet for each individual. Knowing the arch index on one side of the body allows for an accurate prediction of the arch index on the opposite side within an individual. The right arch index was larger in 55% of the sample. All other correlations were negligible, and the presence or absence of specific insertions was not an accurate predictor of either arch measure. The accumulation of multiple variable insertions did not have any impact on the arch measurements.
107

Facial fatness as a complicating factor in facial reconstruction

Clarke, Carrie Anna-Marie January 2015 (has links)
Includes bibliographical references / Although it is a reasonable assumption that a significant proportion of the variation in facial tissue thicknesses comes from anatomical differences between populations, we do not know how much of normal variation is caused by including the full range of individual obesity or slimness. Current population standard soft tissue thickness data used in facial reconstructions ignores the variation between individuals which, in theory, could be greater than the variation between populations or sexes. The aim of this study was to test if facial tissue thickness is due to the amount of sub - cutaneous fat, sex or racial origins. Methods currently used do not give a true reflection of the individual because they ignore the variation in fatness. An initial study determined if a corrective value for the non - linear distortion found between radiographic images and the physical tissues was needed. This was done by imaging cadaver heads and taking measurements from the images and the physical heads. The results demonstrated that measurements taken from LODOX® images are analogous with soft tissue measurements. Volunteers were then sought from the student body and had physical measurements and X - rays taken. The measurements allowed for both BMI and body fat percentage to be calculated. Analysis showed that body fat percentage had less of an impact than BMI, with the areas of the face most affected by change in fatness being around the chin, jaw and cheek. Analysis of the variances showed that fatness has a low impact on the soft tissues of the different ancestry groups, while having a greater impact on the soft tissues of the different sexes. The effect of changing fatness on the soft tissues is not seen in all areas of the face, but to ignore it in facial reconstruction ignores that the success of a reconstruction is not exactness but in its ability to incite recognition and lead to potential identification of the unknown target individual.
108

Stature estimation: evaluating regression equations for different population groups in South Africa

Arendse, Liesl Margo 25 January 2019 (has links)
Stature estimations from regression formulae are used by forensic anthropologists in constructing a biological profile from unidentified human remains. Regression formulae are used to calculate total skeletal height or living stature when incomplete, fragmentary or burned human remains are recovered. This study aimed to evaluate the reliability of the total skeletal height regression formulae from (1) Lundy and Feldesman (1987), and (2) Dayal et al. (2008) when compared to total skeletal height from the full anatomical method (Fully’s method), in a contemporary South African population. The use of these regression formulae to estimate total skeletal height of South Africans of Mixed Ancestry was investigated as no population-specific standards exist for this group. Additionally, the reliability of the generic femur/stature ratio (Feldesman et al., 1990) to estimate living stature for all three population groups was investigated. Measurements were taken from 229 individuals comprising of South Africans of Mixed Ancestry, African Descent and European Descent from South African skeletal collections. ANOVA’s and paired t-tests were used to determined if there was a significant difference (p<0.05) between (1) estimated total skeletal height from regression formulae and that from Fully’s method, and (2) the estimated living stature from the femur/stature ratio and a calculated living stature from Fully’s total skeletal height with soft tissue and age correction factors. No significant difference (p>0.05) was found between South Africans of African Descent and Mixed Ancestry’s calculated total skeletal height, but both were significantly different (p<0.000) to individuals of European Descent. Results indicate that the Lundy and Feldesman (1987) regression formulae should be re-assessed for contemporary South Africans of African Descent and results from the Dayal et al. (2008) regression formulae indicate that the formulae are still relevant for contemporary South Africans of European Descent. Additionally, new regression formulae should be developed to enable forensic or physical anthropologists to estimate total skeletal height of Mixed Ancestry individuals. The femur/stature ratio’s living stature were significantly different (p<0.000) from the calculated living stature, and generally overestimated it for maximum femur lengths greater than 50cm.
109

The Bony pelvis scars of parturition and factors Influencing their manifestation

Maass, Petra January 2012 (has links)
Includes abstract. / Includes bibliographical references. / The aim of this study was to measure and describe the range of variation of several sites on the pelvis reported to display parturition scarring in a skeletal sample of 391 individuals (230 males and 161 females). The scar features, body and pelvic dimensions were compared according to the sex, age and time period of origin of the individuals. Correlation tests were performed to identify potential relationships between scar features, while Principal Component Analysis was used to assess the influence of body and pelvic size on scar manifestation.
110

The effects of HIV-1 infection on subcortical brain structures in children receiving ART : a structural MRI study

Randall, Steven Ronald January 2015 (has links)
INTRODUCTION This project investigated volumetric differences in certain subcortical structures as measured on high-resolution structural Magnetic Resonance Imaging (MRI) scans traced manually. The sample comprised 79 5-year old children, 52 with HIV and 27 uninfected controls. Infected children were all stable on antiretroviral therapy (ART) and were from the Children with HIV early antiretroviral (CHER) cohort who have been followed since birth. The study aimed to investigate the long-term effects of HIV and ART on the developing brain. While high-resolution structural data has been analysed using automated FreeSurfer to determine volume and cortical thickness, manual tracing remains the gold standard. Thus, manual tracing was used to validate automated measures and investigate subtle group differences in selected regions of interest. METHODS Extensive clinical data were available for all participants in the study. MR images were AC-PC transformed and converted to analyse format. Structures were traced using MultiTracer software. Structures selected included the caudate, nucleus accumbens (NA), putamen (Pu), globus pallidus (GP) and corpus callosum (CC). Four of these structures occur bilaterally. Tracing was performed in 79 subjects. Three subjects were excluded due to poor quality images or pathology; 5 HIV-1 infected children were excluded as they were not randomized between treatment groups. Certain subjects were retraced for inter and intrarater reliabilities. The effect and association of ethnicity, age, birthweight and sex as possible confounders were investigated. As the groups were not well matched for ethnicity, all Cape Coloured children were excluded from further analyses. Analysis of variance was used to test the effect on structure size between HIV-1 infected children and controls, as well as between 3 treatment arms (ART deferred until clinical criteria were met, early ART for 40 weeks, early ART for 96 weeks) and uninfected controls. Analysis of covariance was used to control for the possible confounding effects of sex and age. Each structure was tested for possible association with clinical variables (CD4, CD8, CD4/CD8 ratio and CD4%) both at enrolment and time of scanning. Linear regressions were modelled using clinical variables that showed significant correlation with structure size whilst controlling for covariates. Congruence between automated FreeSurfer and manual segmentation were evaluated via Bland-Altman, Pearson r and Cronbach's alpha.

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