18 research outputs found

    Exploring the effect of simulated Motion Conditions on Task Performance

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    This thesis explored the effect that four different areas of motion conditioning presented in a motion simulator had on defence-force based task performance. It is produced in conjunction with the Defence Science and Technology Organisation, Land Operations Division, to expand their understanding of how these conditions may affect their personnel. The four conditions are explored are Motion Sickness, Motion Fatigue, Motion Perception and Mental Workload under motion conditions. All studies involved first year psychology students enrolled at the University of Sydney in accordance with the University’s ethical guidelines (2013/388). In the study of Motion Sickness, nausea was shown to have very little detrimental effect on task performance. In long term driving exposure there was a slight negative effect on the reaction time that was linked to motion sickness symptoms. Two styles of driving were researched for Motion Fatigue: boredom and constant motion. The boredom drive was seen to have a slightly negative effect on performance compared to the motion drive. In analysing biomarkers of fatigue relevant to a defence context, the best indicators were respiratory rate and the Root Mean Square of Successive Differences between normal heart beats. In Motion Perception, 6-axes of motion at 3 intensities were tested using Defence force tasks to determine whether any one axis, or a certain intensity, negatively affected performance more than others. Higher errors occurred in the Roll direction. The Pitch direction was the least comfortable for participants. In the final chapter of Mental Workload under motion, increased workload did not have a great impact on performance, although further studies are needed. In an analysis of subjective scales of workload in simple tasks, participants were able to accurately determine their task performance. From a bio-measure perspective, pupil diameter and respiratory rate were found to be the most indicative of changing levels of workload

    Subtyping of oligo-astrocytic tumours by comparative genomic hybridization.

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    Item does not contain fulltextOligo-astrocytic tumours (OAs) histologically show both oligodendroglial and astrocytic differentiation. Unequivocal criteria for delineation of OAs from pure oligodendroglial (Os) and astrocytic (As) tumours and for grading of OAs are lacking. Molecular genetic analysis may allow for a better characterization of OAs and thereby guide prognostic and therapeutic decisions. Comparative genomic hybridization (CGH) was performed on 39 gliomas with variable phenotypic expression of histological features characteristic of both astrocytic and oligodendroglial differentiation. The results show that OAs are genetically more heterogeneous than Os. In addition to the "-1p/-19q" and "10" subtypes that have been previously recognized, two additional genetic subtypes, "intermediate" and "other", were identified in the present study. "Intermediate" OAs likely represent progression from "-1p/-19q" tumours. The "other" subtype appears to represent an additional, heretofore unrecognized, genetic pathway(s). Application of rigorously "strict" histopathological criteria, as opposed to "relaxed" criteria, for the selection of oligo-astrocytic tumours resulted in a higher percentage of "-1p/-19q" tumours, but some "-1p/-19q" tumours might be missed. The results suggest that molecular genetic analysis is a useful and valid additional tool for the classification of gliomas, particularly for the significant subset of tumours in which subjective histopathological criteria are insufficient for an unequivocal distinction between Os, As, and mixed OAs

    Inverse correlation between genetic aberrations and malignancy grade in ependymal tumors: a paradox?

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    Contains fulltext : 57800.pdf (publisher's version ) (Closed access)OBJECTIVE: The goal of our study was to investigate the inverse correlation between number of genetic aberrations and malignancy grade in ependymal tumors at the ploidy level. METHODS: we examined seven myxopapillary ependymomas (mpEs) (WHO grade I), 28 spinal and cerebral ependymomas (Es) (WHO grade II), and 18 cerebral anaplastic ependymomas (aEs) (WHO grade III) using image DNA cytometry. The ploidy status was correlated with clinicopathological characteristics and with the results obtained by comparative genomic hybridization (CGH) analysis that we performed in about half of these tumors. RESULTS: mpEs were exclusively located in the spinal cord and aEs in the cerebrum only, whereas Es were located in both the spinal cord and brain. We found aneuploidy or tetraploidy to be common in the group of mpEs (6 out of 7) and much less frequent in Es (6 out of 28) and aEs (4 out of 18). Three-year postoperative survival was 100% for mpEs, 100% for spinal Es, 92% for cerebral Es, and 33% for aEs. Our CGH results in a selection of these tumors revealed the highest number of genetic aberrations in the mpEs (average 16; n = 2), a lower number in Es (average 12; n = 11) and the lowest number in aEs (average 5; n = 6). Interestingly, in the group of Es and aEs, a high number of genetic aberrations as detected by CGH was not correlated with aneuploidy or tetraploidy. Three patients, all with mpEs had local seeding. CONCLUSION: These results underline that mpEs are distinctly different from Es and aEs at the genetic level and that extensive genomic alterations and aneuploidy in ependymal tumors are not in itself an indicator of malignant behavior

    The ileo neo rectal anastomosis: long-term results of surgical innovation in patients after ulcerative colitis and familial adenomatous polyposis

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    Contains fulltext : 117801.pdf (publisher's version ) (Closed access)PURPOSE: Restorative proctocolectomy with ileo neo rectal anastomosis (INRA) combines cure of ulcerative colitis (UC) or familial adenomatous polyposis (FAP) with restoration of intestinal continuity. Evaluation of long-term results was needed to determine if there is a place for INRA in the armamentarium of a surgeon besides the ileal pouch anal anastomosis (IPAA). METHODS: All patients with INRA were included in the analysis. Patient demographics and clinical and follow-up data (morbidity, dietary problems, defecation frequency, fecal continence, anal and neorectal physiology, and neorectal mucosa assessment) were registered prospectively. RESULTS: Seventy-nine patients were enrolled, and in 58 patients (50 UC, 8 FAP), INRA was successful. In 21 patients, intraoperative conversion to IPAA was needed. In 49 patients with INRA, a functional reservoir was achieved. No pelvic sepsis or bladder or sexual dysfunction occurred. Thirteen patients experienced episodes of reservoir inflammation. Median bowel movements of six (5, 8) with a nocturnal defecation frequency of one were recorded with fecal continence or minor incontinence. Anal manometry and neorectal physiology showed a decrease in resting pressure and an increase in squeeze pressure and maximum tolerated volume. The median follow-up was 8.1 years (6.7, 10.1). CONCLUSIONS: This is an example of a surgical innovation with a theoretical potential to be superior to the current technique. This potential was not confirmed in short- and long-term evaluations. Hence, IPAA is currently the best available alternative to a conventional ileostomy

    A Hypermethylated Phenotype Is a Better Predictor of Survival than MGMT Methylation in Anaplastic Oligodendroglial Brain Tumors: A Report from EORTC Study 26951

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    Item does not contain fulltextPURPOSE: The MGMT promoter methylation status has been suggested to be predictive for outcome to temozolomide chemotherapy in patients with glioblastoma (GBM). Subsequent studies indicated that MGMT promoter methylation is a prognostic marker even in patients treated with radiotherapy alone, both in GBMs and in grade III gliomas. EXPERIMENTAL DESIGN: To help determine the molecular mechanism behind this prognostic effect, we have conducted genome-wide methylation profiling and determined the MGMT promoter methylation status, 1p19q LOH, IDH1 mutation status, and expression profile on a series of oligodendroglial tumors [anaplastic oligodendrogliomas (AOD) and anaplastic oligoastrocytomas (AOA)] within EORTC study 26951. The series was expanded with tumors of the same histology and treatment from our own archive. RESULTS: Methylation profiling identified two main subgroups of oligodendroglial brain tumors of which survival in the CpG island hypermethylation phenotype (CIMP(+)) subgroup was markedly better than the survival of the unmethylated (CIMP(-)) subgroup (5.62 vs. 1.24 years; P < 0.0001). CIMP status correlated with survival, MGMT promoter methylation, 1p19q LOH, and IDH1 mutation status. CIMP status strongly increases the predictive accuracy of survival in a model including known clinical prognostic factors such as age and performance score. We validated our results on an independent data set from the Cancer Genome Atlas (TCGA). CONCLUSION: The strong association between CIMP status and MGMT promoter methylation suggests that the MGMT promoter methylation status is part of a more general, prognostically favorable genome-wide methylation profile. Methylation profiling therefore may help identify AODs and AOAs with improved prognosis. Clin Cancer Res; 17(22); 7148-55. (c)2011 AACR

    Chromosome 1p loss evaluation in anaplastic oligodendrogliomas.

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    Contains fulltext : 69651.pdf (publisher's version ) (Closed access)The chromosome (chr) 1p deletion is a favorable biomarker in oligodendroglial tumors and is even more powerful a marker when combined with chr 19q loss. As a result, the 1p deletion is taken into account more and more in clinical trials and the management of patients. However, the laboratory technique implemented for detection of this biomarker has been a topic of debate. To illustrate the usefulness of evaluating multiple loci, we here report two anaplastic oligodendrogliomas that were investigated using fluorescent in situ hybridization (FISH) and bacterial artificial chromosome (BAC)-array-based comparative genomic hybridization (aCGH). Indeed, segmental analysis using FISH, limited to chr 1p36 was unable to discriminate between complete and partial deletions of chrs 1p. However, complete and partial deletions of 1p are reported to have distinct clinical outcomes. Our results illustrate that aCGH (or other multiple loci technologies) provide complementary information to single locus technologies such as FISH because multiple loci technologies can evaluate the extent of the chr 1p deletion

    Prevalence and Risk Factors for Hyposalivation and Xerostomia in Childhood Cancer Survivors Following Different Treatment Modalities-A Dutch Childhood Cancer Survivor Study Late Effects 2 Clinical Study (DCCSS LATER 2)

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    Simple Summary Salivary gland dysfunction is an underestimated late effect in childhood cancer survivors (CCS). The objective of this cross-sectional study, part of the multidisciplinary multicenter Dutch Childhood Cancer Survivor Study Late Effects 2 (DCCSS LATER 2), was to assess the prevalence of and risk factors for hyposalivation and xerostomia in CCS with a long-term follow-up exceeding 15 years. From February 2016 until March 2020, 292 CCS were included. The prevalence of hyposalivation was 32% and the prevalence of xerostomia was 9.4%. Hyposalivation and xerostomia did not correlate significantly. Risk factors for hyposalivation were female gender and a higher dose of radiotherapy (>12 Gy) to the salivary glands. Screening for hyposalivation during long-term follow-up in CCS is recommended in order to provide optimal oral supportive care aimed to improve oral health. Background: Limited data are available on the risk factors of salivary gland dysfunction in long-term childhood cancer survivors (CCS). The objective of this cross-sectional study, part of the multidisciplinary multicenter Dutch CCS Study Late Effects 2 (DCCSS LATER 2), was to assess the prevalence of and risk factors for hyposalivation and xerostomia in CCS. Methods: From February 2016 until March 2020, 292 CCS were included. Data with regard to gender, age at study, diagnosis, age at diagnosis, and treatment characteristics were collected, as well as the unstimulated (UWS) and stimulated whole salivary flow rate (SWS). Xerostomia was assessed with the Xerostomia Inventory (XI) questionnaire. Multivariable Poisson regression analyses were used to evaluate the association between potential risk factors and the occurrence of hyposalivation. Results: The minimum time between diagnosis and study enrollment was 15 years. The prevalence of hyposalivation was 32% and the prevalence of xerostomia was 9.4%. Hyposalivation and xerostomia were not significantly correlated. Risk factors for hyposalivation were female gender and a higher dose of radiotherapy (>12 Gy) to the salivary gland region. Conclusion: Considering the importance of saliva for oral health, screening for hyposalivation in CCS is suggested in order to provide optimal oral supportive care aimed to improve oral health.Metabolic health: pathophysiological trajectories and therap
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