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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.
31

A vulnerability-stress model for the course of schizophrenia ?

Erickson, David Harry 05 1900 (has links)
Despite a prevailing paradigm that emphasizes an interaction of vulnerability and stress to account for the etiology of schizophrenia, diathesis—stress models of subsequent course and outcome of this disorder are rare. Even the simpler stress— process model, where the influence of stressors is mediated by supportive social relationships, has received little attention in studies of the course of schizophrenia. The objective of this study was to assess the following components of a diathesis—stress model as they predict the five-year outcome of first-episode schizophrenia: (1) stressful life events; (2) supportive social relationships; (3) brain lateral ventricle size; and (4) smooth pursuit eye movements. As part of the Greater Vancouver M.A.P. Project, we recruited first-episode DSM-III schizophrenia and affective psychosis patients. At intake to the study, their social relationships, smooth pursuit eye movement function, and brain ventricle size were assessed. Life events in the previous year were measured at intake; events over the following 18 months were assessed in two later interviews. Five years later we assessed outcome, using a global rating of social and occupational functioning. Descriptive results showed substantial variability within the schizophrenia group at intake and outcome. The trajectory of adaptive functioning over time was remarkably similar for the schizophrenic and affective psychosis groups. Of the four hypothesized predictors, only social relationships were associated (p=.O3) with five—year outcome. The number of life events was not associated with five—year outcome, nor was either of the biological risk factors. As a result, the predictor variables could not be combined in either a stress—process model or a vulnerability—stress model of the course of schizophrenia. That social relationship variables are associated with five-year outcome supports earlier findings regarding 18-month outcome, including the differing predictive roles for family and nonfamily relationships. The absence of hypothesized results for the life events data probably indicates that too much time had passed between outcome and the events as measured. Finally, that brain ventricle size and eye-movement dysfunction predict 18-month but not five—year outcome may indicate that impairment due to biological factors is expressed only in the early stages of schizophrenia. / Arts, Faculty of / Psychology, Department of / Graduate
32

A contribution to the etio-pathogenesis of chronic middle ear effusions

Kuschke, Erich Reinier Hermann 15 May 2017 (has links)
No description available.
33

The chromatographic determination of fusarium toxins in maize associated with human oesophageal cancer

Sydenham, Eric William January 1989 (has links)
The necessity to obtain accurate and reliable data pertaining to the range and/or levels of mycotoxin contamination in a variety of food and feed substrates, intended for human or animal consumption, has therefore, become important. An integral part of this study will be the provision of the most suitable analytical methods for the determination of selected Fusarium mycotoxins, in maize. The culmination will be the application of those selected methodologies to a series of Transkeian maize samples associated with human oesophageal cancer-risk.
34

Enzymatic metabolic activation in hepatocellular and nasopharyngeal carcinomas in Hong Kong Chinese. / CUHK electronic theses & dissertations collection

January 1997 (has links)
by Ng Chor Yin Maggie. / Thesis (Ph.D.)--Chinese University of Hong Kong, 1997. / Includes bibliographical references (p. 358-403). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Mode of access: World Wide Web.
35

A multi-scale study of bone mineralization and bone quality in adolescent idiopathic scoliosis / CUHK electronic theses & dissertations collection

January 2015 (has links)
Introduction. The etiology of adolescent idiopathic scoliosis (AIS) is largely unknown. AIS was well-documented to be associated with low bone mineral density (BMD) and abnormal bone quality. We hypothesized that bone matrix mineralization is abnormally low in AIS and that the abnormality could lead to the observed osteopenia and abnormal bone quality that might contribute to the etiopathogenesis of AIS. / Objectives. 1. To verify the abnormal bone mass and bone quality in AIS Vs normal matched controls 2. To study the bone matrix mineralization status, micro-architecture and mechanical property in AIS Vs controls 3. To study the cellular and molecular characterization of bone formation and resorption in AIS Vs controls 4. To study the possible association of abnormal bone quality with the curve progression / Methods. 1. The case-control study in Chapter 3 included 257 AIS and 187 age- and gender-matched normal controls. BMD and bone quality were measured with dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT) in vivo. 2. Chapter 4 studied iliac crest bone biopsies from 28 AIS and 9 controls. Bone mineral status was measured with DXA, micro-computed tomography (micro-CT) and energy dispersive X-ray spectroscopy; bone micro-architecture and mechanical property were measured with micro-CT, individual trabeculae segmentation analysis and finite element analysis (FEA). 3. Chapter 5 included 46 AIS and 23 controls. The mRNA expression of the bone tissue and primary osteoblastic and osteoclastic activities related to bone mineralization were studied. 4. Chapter 6 included 82 AIS patients. Bone quality was measured with HR-pQCT in vivo at baseline. Comparison was made between the stable and the progressive patients followed for more than 1.5 years after skeletal maturity. / Results. 1. In Chapter 3, both osteopenic and non-osteopenic AIS had lower areal BMD (aBMD) and trabecular and cortical volumetric BMD (vBMD) than their matched normal controls, with the non-osteopenic AIS reaching statistical significance (P<0.05). Osteopenic AIS had larger cortical perimeter and trabecular area than the osteopenic controls after adjustments of confounding factors (P<0.05); non-osteopenic AIS had significantly lower cortical area, thickness and vBMD than the non-osteopenic controls (P<0.05), and marginally significant cortical area and thickness after adjustments. 2. In Chapter 4, AIS had lower bone calcium content (Ca/C ratio) in trabecular bone than controls (P<0.05); moreover, AIS had significantly lower trabeculae rod number and thickness and mechanical property (P<0.05). Osteopenic AIS had significantly lower rod and plate micro-architecture (P<0.05) and 11.3% of decline of FEA mechanical property than non-osteopenic AIS. 3. In Chapter 5, AIS had lower expression of osteogenic markers (ALP and RUNX2) (P=0.009-0.132) and higher expression of extracellular matrix markers (COL1 and BGLAP) (P =0.109-0.132) in bone formation, and higher expression of bone resorption markers (TRAP and CTSK) (P =0.045-0.100). AIS also showed lower osteogenic differentiation potential and calcium nodule formation ability than controls. Within the subgroups, osteopenic AIS showed lower osteoblastic differentiation (P=0.009) and 41.8% decline of calcium formation abilities (P =0.186). The primary osteoblasts from the osteopenic AIS had higher pro-osteoclastogenic potential (P =0.034) and higher osteoclastogenic differentiation potential on osteoclasts. 4. In Chapter 6, progressive AIS had significantly lower aBMD, total vBMD and lower cortical area and thickness after adjustments (P<0.05). The predictive model showed that bone quality model was more predictive than the aBMD model which was more predictive than the basic model on curve progression. / Discussions The present study verified all the AIS had lower BMD and abnormal bone quality. It provided a direct evidence of lower calcium content in AIS which might contribute to the observed lower BMD. Therefore, these abnormalities in AIS could represent a spectrum of severity which is labeled as osteopenic or non-osteopenic with DXA and partly explained by the cellular and molecular studies. The longitudinal study showed AIS with poorer bone quality have significantly higher probability of curve progression. In summary, the present findings supported and confirmed our proposed hypothesis. / 引言:有研究提示AIS低骨量與骨質量異常與病因學有關。我們推測,AIS的骨基質礦化可能異常降低,進而導致低骨量和異常骨質量發生,這可能與AIS病因学有關。 / 目的:1. 驗證AIS的低骨量及骨質量異常 2. 调查AIS骨基質礦化、骨微結構和機械性能狀態 3. 研究AIS關於骨礦化的細胞分子功能 4. 探讨AIS骨質量與側彎進展間的關聯 / 方法:1. 通過雙能吸收儀和高分辨率外周定量CT比较低骨量和非低骨量AIS与其正常對照間骨密度和骨質量的差异 2. 通過雙能吸收儀、顯微CT和掃描電鏡與能量色散光譜儀檢測骨礦物質含量,及顯微CT、骨小梁個體分割和有限元分析法檢測骨微結構和力學性能,比較AIS和正常對照及AIS亞組間的差異。3. 通過檢測與骨礦化相關的mRNA,和原代成骨和破骨細胞培養,比較AIS和正常對照及AIS亞組間的差異。4. 通過高分辨率外周定量CT縱向隨診AIS患者,比較進展組和穩定組間骨質量差異。 / 結果:1. 低骨量和非低骨量AIS均比正常對照組骨密度和骨質量降低。2. AIS骨鈣含量降低,骨微結構和機械性能顯著異常。3. AIS骨形成標記物降低、骨吸收標記物升高,成骨分化潛能降低。低骨量AIS比非低骨量AIS成骨細胞分化能力降低和親破骨分化潛能升高。4. 側彎進展AIS骨密度和骨質量顯著異常。 / 討論:本研究結果支持我們的假設:AIS骨基質礦化異常,導致低骨量和異常骨質量,提示與AIS發病機理相關聯。 / Wang, Zhiwei. / Thesis Ph.D. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 243-261). / Abstracts also in Chinese; appendixes includes Chinese. / Title from PDF title page (viewed on 09, September, 2016). / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only.
36

Role of intestinal trefoil factor in gastric carcinogenesis. / CUHK electronic theses & dissertations collection

January 2005 (has links)
Induction of ITF expression significantly enhanced invasion of Rat-2 (1.8-folds) without promoting proliferation. The increase in invasiveness was accompanied by an upregulation of beta-catenin (18.0%) and MMP-9 (67.8%), and downregulation of E-cadherin (29.7%) and TIMP-1 (34.7%). Silencing ITF in MKN45 markedly delayed the onset of tumor progression by Day 6 and reduced the tumor volume by 85% by Day 14. ITF siRNA significantly attenuated angiogenesis in vivo and in vitro. The effects of silencing ITF were mediated through transcriptional upregulation of the Bax (114%), Bak (89%), Ang-2 (89%) and Tie-2 (399%). Bcl-2, Bcl-xL, VEGF and Ang-1 expressions were not significantly altered. Silencing ITF in gastric cancer cells increased the effect of cisplatin-induced apoptosis in a dose-dependent manner. / Our findings suggested that ITF plays a role in invasion, proliferation and angiogenesis. The mechanisms involve regulation of catenin-cadherin complexes, balance of MMPs/TIMPs, proapoptotic Bcl-2 family members and Ang-2/Tie-2 system. Silencing ITF enhanced the chemotherapeutic response of gastric cancer cells to cisplatin. Blocking ITF expression using RNA interference may have a potential therapeutic application in gastric cancer. (Abstract shortened by UMI.) / The aim of this project was to define the role of ITF in gastric carcinogenesis. The thesis consisted of two parts of scientific studies to investigate the effects of: inducing ITF expression on the proliferation and invasion of non-tumorigenic rat fbroblast cells (Part 1); and silencing ITF on the proliferation, angiogenesis and chemotherapeutic response in gastric cancer cells (Part 2). / Chan Yik Wai. / "August 2005." / Adviser: Francis Ka Leung Chan. / Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3719. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 124-139). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.
37

Cigarette smoking enhances the expression of thromboxane synthase and stimulates lung cancer stem cells, leading to the development of lung cancer / CUHK electronic theses & dissertations collection

January 2015 (has links)
Liu, Yi. / Thesis Ph.D. Chinese University of Hong Kong 2015. / Includes bibliographical references (leaves 154-175). / Abstracts also in Chinese. / Title from PDF title page (viewed on 25, October, 2016).
38

Ulcerative colitis and cancer : with special reference to the increased colorectal cancer risk /

Karlén, Per, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.
39

Plasmodium falciparum malaria and anaemia in childhood /

Ekvall, Håkan, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 4 uppsatser.
40

Community acquired bacteraemia : a prospective survey of 239 cases

Rayner, Brian L 06 April 2017 (has links)
The incidence and epidemiology of bacteraemia has been widely reported in the United States and Europe but little data is available from Southern Africa. In addition, most studies have concentrated on the overall incidence of bacteraemia, on individual organisms, or clinical situations, and it is difficult to interpret the data from these studies with regard to community acquired bacteraemia. From a retrospective survey of summaries from a single medical ward at Groote Schuur Hospital it was estimated that bacteraemia accounted for about 4% of the total admissions. It was therefore thought useful to provide clinicians particularly at Groote Schuur Hospital with information about community acquired bacteraemia to improve overall patient management. With this in mind it was decided to undertake a comprehensive prospective study of community acquired bacteraemia at Groote Schuur Hospital.

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