704 research outputs found
Fracture patterns and petrophysical properties of carbonates undergoing regional folding : A case study from Kurdistan, N Iraq
Acknowledgements The authors thank the Ministry of Natural Resources in Iraqi Kurdistan Region for permission to publish this paper. Gulf Keystone Petroleum Ltd. and HKN Energy Ltd. are acknowledged for providing the subsurface datasets. Great thanks to Colin Taylor at the University of Aberdeen for his assistance in the laboratory work. Thoughtful reviews by two anonymous referees improved the clarity of the paper. Graham Banks is thanked for his helpful and constructive review on a late version of the manuscript, which has significantly improved this paper.Peer reviewedPostprin
Cox-2 Inhibition Enhances the Activity of Sunitinib in Human Renal Cell Carcinoma Xenografts
Background: Sunitinib (Su), a tyrosine kinase inhibitor of VEGFR, is effective at producing tumour response in clear cell renal cell carcinoma (cRCC), but resistance to therapy is inevitable. As COX-2 is a known mediator of tumour growth, we explored the potential benefit of COX-2 inhibition in combination with VEGFR inhibition in attempts at delaying tumour progression on Su. Methods: COX-2 expression was compared with areas of hypoxia in tumours that progressed on Su vs untreated tumours. Mice bearing human cRCC xenografts were treated with Su and the COX-2 inhibitor, celecoxib, and the effects on tumour growth were assessed. Sequential vs concurrent regimens were compared. Results: COX-2 expression was increased in cRCC xenografts in areas of tumour hypoxia. The combination of Su and celecoxib achieved longer times to tumour progression compared to treatment with either agent alone or to untreated control animals in four models. This effect was seen with concurrent but not with sequential therapy. Conclusion: COX-2 inhibition can extend the effectiveness of VEGFR inhibition. This effect is dependent on the timing of therapy. Clinical trials combining Su and COX-2 inhibitors should be considered as a means delaying time to progression on sunitinib in patients with metastatic cRCC
Arterial spin labelling reveals an abnormal cerebral perfusion pattern in Parkinson's disease
There is a need for objective imaging markers of Parkinson's disease status and progression. Positron emission tomography and single photon emission computed tomography studies have suggested patterns of abnormal cerebral perfusion in Parkinson's disease as potential functional biomarkers. This study aimed to identify an arterial spin labelling magnetic resonance-derived perfusion network as an accessible, non-invasive alternative. We used pseudo-continuous arterial spin labelling to measure cerebral grey matter perfusion in 61 subjects with Parkinson's disease with a range of motor and cognitive impairment, including patients with dementia and 29 age- and sex-matched controls. Principal component analysis was used to derive a Parkinson's disease-related perfusion network via logistic regression. Region of interest analysis of absolute perfusion values revealed that the Parkinson's disease pattern was characterized by decreased perfusion in posterior parieto-occipital cortex, precuneus and cuneus, and middle frontal gyri compared with healthy controls. Perfusion was preserved in globus pallidus, putamen, anterior cingulate and post- and pre-central gyri. Both motor and cognitive statuses were significant factors related to network score. A network approach, supported by arterial spin labelling-derived absolute perfusion values may provide a readily accessible neuroimaging method to characterize and track progression of both motor and cognitive status in Parkinson's diseas
The effect of diagenesis and facies distribution on reservoir quality in the Permian sandstones of the Toolachee gas field, southern Cooper Basin, South Australia
Thesis (M.S.) -- University of Adelaide, Dept. of Geology and Geophysics, 199
Routine germline <i>BRCA1</i> and <i>BRCA2 </i>testing in ovarian carcinoma patients:analysis of the Scottish real life experience
Objective:
To determine the rate of germline BRCA1 and BRCA2 mutations in Scottish ovarian cancer patients before and after a change in testing policy.
Design:
Retrospective cohort study.
Setting:
Four cancer/genetics centres in Scotland.
Population:
Ovarian cancer patients undergoing germline BRCA1 and BRCA2 (gBRCA1/2) gene sequencing before 2013 (‘old criteria’; selection based solely on family history), after 2013 (‘new criteria’; sequencing offered to newly presenting non-mucinous ovarian cancer patients) and the ‘prevalent population’ (who presented before 2013, were not eligible for sequencing under the old criteria but were sequenced under the new criteria).
Methods:
Clinicopathological and sequence data were collected before and for 18 months after this change in selection criteria.
Main Outcome Measures:
Frequency of germline BRCA1, BRCA2, RAD51C and RAD51D mutations.
Results:
Of 599 patients sequenced, 205, 236 and 158 were in the ‘old criteria’, ‘new criteria’ and ‘prevalent’ populations respectively. The frequency of gBRCA1/2 mutations was 30.7%, 13.1% and 12.7% respectively. The annual rate of gBRCA1/2 mutation detection was 4.2 before and 20.7 after the policy change. 48% (15/31) ‘new criteria’ patients with gBRCA1/2 mutations had a Manchester score <15 and would not have been offered sequencing based on family history criteria. In addition, 20 gBRCA1/2 patients were identified in the prevalent population. The prevalence of gBRCA1/2 mutations in patients >70 years was 8.2%.
Conclusions
Sequencing all non-mucinous ovarian cancer patients produces much higher annual gBRCA1/2 mutation detection with the frequency of positive tests still exceeding the 10% threshold upon which many family history based models operate
From hot to cold - The temperature dependence on rock deformation processes : An introduction
Acknowledgements We thank Bill Dunne for his work as Journal of Structural Geology overseeing editor, and to all the reviewers of manuscripts submitted to this special issue. We gratefully acknowledge Richard D. Law, Paul D. Bons, Albert Griera and Maria-Gema Llorens for reviewing this article prior to submission. The programme, abstract and field excursion guides for the DRT-2017 Inverness conference are available at: https://www.abdn.ac.uk/geosciences/events/downloads-1112.php.Peer reviewedPostprin
Multiple episodes of sand injection leading to accumulation and leakage of hydrocarbons along the San Andreas/San Gregorio fault system, California
Acknowledgements We acknowledge the reviews of three anonymous referees and are also very grateful to Andrew Hurst and David Iacopini for their critical comments of an earlier version of the paper. We also wish to thank Denis Bureau and Antonella Gatto for their support in the field.Peer reviewedPostprin
Issues raised developing AQuRate (an authoring tool that uses the question and test interoperability version 2 specification)
The IMS Question & Test Interoperability (QTI) specification has existed for many years, and there are a few tools for authoring questions in early versions of the specification. However, the new QTIv2 specification was unsupported in any existing authoring environment. The AQuRate project was funded by JISC’s capital project program to fill this gap. AQuRate is one of three JISC projects, which together aimed to support the whole e-assessment process, from authoring (AQuRate at Kingston University) to storage (Minibix at Cambridge) and finally to a delivery/assessment development (ASDEL at Southampton). This paper considers issues raised during the creation of the tool: data modelling, graphical user interface design, and use cases. It ends raising issues currently effecting on-going development
High dose intermittent sorafenib shows improved efficacy over conventional continuous dose in renal cell carcinoma
<p>Abstract</p> <p>Background</p> <p>Renal cell carcinoma (RCC) responds to agents that inhibit vascular endothelial growth factor (VEGF) pathway. Sorafenib, a multikinase inhibitor of VEGF receptor, is effective at producing tumor responses and delaying median progression free survival in patients with cytokine refractory RCC. However, resistance to therapy develops at a median of 5 months. In an effort to increase efficacy, we studied the effects of increased sorafenib dose and intermittent scheduling in a murine RCC xenograft model.</p> <p>Methods</p> <p>Mice bearing xenografts derived from the 786-O RCC cell line were treated with sorafenib according to multiple doses and schedules: 1) Conventional dose (CD) continuous therapy; 2) high dose (HD) intermittent therapy, 3) CD intermittent therapy and 4) HD continuous therapy. Tumor diameter was measured daily. Microvessel density was assessed after 3 days to determine the early effects of therapy, and tumor perfusion was assessed serially by arterial spin labeled (ASL) MRI at day 0, 3, 7 and 10.</p> <p>Results</p> <p>Tumors that were treated with HD sorafenib exhibited slowed tumor growth as compared to CD using either schedule. HD intermittent therapy was superior to CD continous therapy, even though the total dose of sorafenib was essentially equivalent, and not significantly different than HD continuous therapy. The tumors exposed to HD sorafenib had lower microvessel density than the untreated or the CD groups. ASL MRI showed that tumor perfusion was reduced to a greater extent with the HD sorafenib at day 3 and at all time points thereafter relative to CD therapy. Further the intermittent schedule appeared to maintain RCC sensitivity to sorafenib as determined by changes in tumor perfusion.</p> <p>Conclusions</p> <p>A modification of the sorafenib dosing schedule involving higher dose intermittent treatment appeared to improve its efficacy in this xenograft model relative to conventional dosing. MRI perfusion imaging and histologic analysis suggest that this benefit is related to enhanced and protracted antiangiogenic activity. Thus, better understanding of dosing and schedule issues may lead to improved therapeutic effectiveness of VEGF directed therapy in RCC and possibly other tumors.</p
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