Saudi Cultural Missions Theses & Dissertations
Permanent URI for this communityhttps://drepo.sdl.edu.sa/handle/20.500.14154/10
Browse
3 results
Search Results
Item Restricted Breast Cancer Treatment Disparities in Patients with Severe Mental Illness: A Systematic Review and Meta-Analysis(Queensland University of Technology, 2024) Alotiby, Meshary; Protani, Melinda; Kisely, Steve; Siskind, DanBackground Disparities in breast cancer treatment for people with pre-existing severe mental illness (SMI) have not been well studied compared to disparities in cancer screening and stage at diagnosis. Aims To conduct a systematic review of the available evidence and investigate whether female breast cancer patients with pre-existing SMI had equitable access to guideline recommended breast cancer treatment compare to those without SMI. Methods We conducted systematic review and meta-analysis of observational studies that were retrieved from PubMed, EMBASE, CINAHL and PsycINFO databases from 22 February 2021 to 26 March 2021. Female breast cancer patients with SMI were included in the analyses. SMI was defined as Schizophrenia, Bipolar disorder, and major depression. Guideline recommended treatment was defined as surgery, chemotherapy, radiotherapy and adjuvant endocrine therapy. Pooled odds ratios, and other estimates, such as hazard ratios and risk ratios were presented. Risk of bias was assessed using Newcasle-Ottawa scale. DerSimonian-Laird random effects models were used. Results 3,325 citations were identified; 10 studies were included, and 4 studies were meta-analysed. Pooled analyses suggested that people with SMI were less likely to receive guideline recommended breast cancer treatment than those without SMI (OR: 0.83; 95% CI: 0.77 to 0.90). Breast cancer patients with schizophrenia had a reduced likelihood for receiving adjuvant radiotherapy (Crude RR: 0.81, 95% CI: 0.77 to 0.85), while those with major depression and bipolar I disorder had lower likelihood of receiving adjuvant chemotherapy (Crude RR: 0.71, 95% CI: 0.60 to 0.84). Conclusions This review identified disparities in breast cancer care for individuals with pre-existing SMI, which contributed to poorer prognosis and excess mortality. Improving collaboration between psycho-oncology teams is advised to address patients’ needs for treatment. Future research is necessary for identifying disparities in primary and systemic treatments and investigating the reasons for treatment inequity.6 0Item Restricted DDL in Context: A meta-analysis of regional variations and predictors of effectiveness in data-driven learning(Saudi Digital Library, 2023) Alojaimi, Reem; Sun, HuiData-driven learning (DDL) provides corpora access to learners as a tool for language learning (Johns, 1991). This meta-analysis attempts to assess the volume of DDL publication and investigates whether regional variations exists. Also, this meta-analysis updates effect size findings, provides a regional analysis, and situates DDL application in the classroom context. This is done through assessing the importance of predictors of effectiveness related to learner-related factors (population variables) and intervention-related factors (treatment variables). The meta-analysis of 98 unique samples shows that DDL is a flourishing field frequently responding to research calls, and that it is an effective intervention with a large effect (g = 1.01). Publication volume is not distributed equally across regions and is mostly centred in Asia and the Middle East, with medium and large effect sizes, respectively. Secondly, population variables and treatment variables within classrooms are evaluated using the multi-model inference approach to determine the importance of each factor in predicting effect size. The results suggest that the most important population variables are region, institution, and sample size, respectively. Experiment duration, corpus type, and DDL interaction type were the most important predictors among the treatment variables. The findings also indicate that the language proficiency level of students and the linguistic target of intervention are not critical predictors of the effectiveness of DDL. These results provide evidence for the versatility of DDL. Despite DDL application being largely exclusive to research and universities (Timmis and Templeton, 2023, p.420), the findings prove that it is also promising in high schools as well as other language teaching institutions and academies. The meta-analysis suggests that medium- and long-term DDL interventions in smaller samples with direct access by learners to public corpora are the most effective.20 0Item Restricted Mechanisms of Infection in an Ecological Model of Host-Parasite Interactions(Saudi Digital Library, 2023-01-09) Alghafli, Hawra; Barribeau, SethTrypanosomatids are evolutionary successful obligate parasites that have two distinct infection life-cycles; some species complete their entire life-cycle in a single host (monoxenous) while others infect two hosts (dixenous). Monoxenous trypanosomtids mostly infect an insect host and are believed to be more primitive and widespread, though not as commonly studied as their dixenous kins. Dixenous trypanosomatids are usually vectored-parasites that encompass etiological agents of several human diseases such African Sleeping Sickness, Chagas disease and Leishmaniasis. Previous studies have examined infection prevalence for subsets of hosts and trypanosomatids, but little is known about whether monoxenous and dixenous trypanosomatids differ in infection prevalence. In chapter 2, I synthesised all published evidence of trypanosomatid infection prevalence for the last two decades using a semi-automated screening protocol. In examining the eligible and included 584 studies that describe infection prevalence, monoxenous species were found to be two-fold more prevalent than dixenous species across all hosts and among insects only. In addition, dixenous trypanosomatids have significantly lower infection prevalence in insects than their non-insect hosts. These results reveal for the first time, a fundamental difference in infection prevalence according to host specificity where vectored species might suffer from lower infection prevalence. These findings will help researchers better understand trypanosomatids in general and further tailor control strategies for various trypanosomatid diseases relevant to human and livestock health. In the Chapter 3 and Chapter 4, I focused on one monoxenous trypanosomatid, the gut parasite Crithidia bombi and its bumblebee host Bombus terrestris. C. bombi and B. terrestris have become an important model system to study host-parasite interactions and the subsequent ecological and evolutionary aspects of their interactions. In Chapter 2, I infected age-controlled workers of B. terrestris with one genotype of C. bombi (08.076; the reference strain which had been fully sequenced) and dissected their guts at 24 hours, 48 hours and 7 days post infection for full transcriptome sequencing of both the parasite and the host. Differential gene expression comparing (I) late infection versus early infection and (II) for each infection time-point versus pre-infection status (log phase in vitro cultures). I found several upregulated potential virulence genes, based on the orthology to Leishmania major, such as two surface glycoproteins and three calpain family cysteine proteases-like proteins. In addition, parasite genes under positive selection, are more dynamically expressed during all the infection time-points than genes that are not under positive selection. Furthermore, I correlated host immune genes with parasite genes and found that co-regulated host and parasites genes were largely antagonistic (negatively correlated) with distinctive clusters of potential gene-gene interactions. Moreover, I also compared the expression patterns of C. bombi with other dixenous and monoxenous trypanosomatids to examine if differentiation responses are governed by conserved gene expression profiles. Overall, I found a slight but significant predictive power across trypanosomatids that is more pronounced among closer related species. My results help shape a better overall understanding of the co-evolved interactions in this host-parasite system and the breadth of similarity and differences in differentiation responses across trypanosomatids that have distinctive life-cycle strategies. Co-infection by multiple strains, or species, of parasites can have important implications for both host immune responses and the manifestation of virulence (a feature of infection that is determined by both parasite and host traits). The process by which co-infection arises may also be important in determining these effects. To understand the role of temporal spacing between infectious exposures and parasite genotype in infection, in Chapter 4, I performed a series of within-host competition assays using transmission load (i.e. the number of parasite cells in the infected host’s faeces) as a fitness proxy. My assays show dramatic increase in faecal parasite abundance when hosts are re-infected by the same genotype. Notably, this advantage of repeated exposure only held when host bees were exposed to two doses of the same genotype but not when they were administered together, or when two different genotypes were used in any combination or order of delivery. This suggests a form of immunosuppression leading to genotype specific precedence based facilitation. Taken together, my work forms a clearer understanding of the previously poorly characterized C. bombi strategies of infection during single and mixed infections. Additionally, the work also highlights a potential fundamental difference between trypanosomatids in infection prevalence based on their life cycle complexity.6 0