Abstract-Impaired angiogenesis could contribute to the increased incidence of coronary and peripheral artery disease in diabetic patients. Angiogenesis is initiated by vascular endothelial growth factor (VEGF), a potent angiogenic cytokine, and suppressed by angiostatin, which is generated by matrix metalloproteinase (MMP)-2 and -9 through proteolytic cleavage of plasminogen. We hypothesized that MMP-2 and -9 were upregulated in the diabetic vasculature, resulting in increased angiostatin production and reduced blood vessel formation. In diabetic internal mammary artery samples (nϭ32) collected from patients undergoing coronary artery bypass grafting surgery, capillary density was only 30% of that in the nondiabetic vessels (nϭ32), whereas VEGF expression was reduced by 48%. Diabetes upregulated the expression and the gelatinolytic activity of MMP-2 and -9. Active MMP-2 and -9 were released from diabetic arteries, but not from nondiabetic vessels, during phenylephrine-induced vasoconstriction. Diabetes enhanced transcription and protein expression of tissue inhibitor of MMP (TIMP)-1 but had an opposite effect on TIMP-2. In diabetic vessels angiostatin was increased by 62% and was positively correlated with the activities of MMP-2 and -9 (r 2 ϭ0.806 and 0.742, respectively). This report indicated a strong correlation between the upregulation of MMP-2 and MMP-9 and the increased angiostatin expression in the human diabetic arterial vasculature. The enhanced angiostatin production with a reduced VEGF formation may explain the pathogenesis of impaired angiogenesis in diabetes mellitus.
Each year funding agencies and academic institutions spend millions of dollars and euros on biobanking. All funding providers assume that after initial investments biobanks should be able to operate sustainably. However the topic of sustainability is challenging for the discipline of biobanking for several major reasons: the diversity in the biobanking landscape, the different purposes of biobanks, the fact that biobanks are dissimilar to other research infrastructures and the absence of universally understood or applicable value metrics for funders and other stakeholders. In this article our aim is to delineate a framework to allow more effective discussion and action around approaches for improving biobank sustainability. The term sustainability is often used to mean fiscally self-sustaining, but this restricted definition is not sufficient for biobanking. Instead we propose that biobank sustainability should be considered within a framework of three dimensions - financial, operational, and social. In each dimension, areas of focus or elements are identified that may allow different types of biobanks to distinguish and evaluate the relevance, likelihood, and impact of each element, as well as the risks to the biobank of failure to address them. Examples of practical solutions, tools and strategies to address biobank sustainability are also discussed.
Structural degeneration was not seen and minor alterations of valve configuration or placement did not affect valve function and were not reliably caused by chest compressions. Vascular or myocardial injury is very common early after transcatheter aortic valve implantation and myocardial amyloidosis represents a relatively frequent potentially significant comorbid condition.
Tumor biobanks have become critical components of the cancer research infrastructure. Consideration of how to place appropriate values on tumor biobanks is important for all stakeholders. At the level of individual biobanks, value is important in determining how to contribute to, utilize, and fund biobanks. At the level of the research system, value is important in determining how to evaluate, rationalize, and sustain or modify the investments in this infrastructure. This review considers approaches and indicators for evaluation of a biobank with a particular focus on utilization, as one important indicator of value, from the perspective of the researcher and funder. The patterns of utilization and the influence of different phases and approaches of research, and types of biobank are described, as well as strategies for biobanks to increase utilization and therefore their value to research.
Human biospecimens are used in 40% of cancer research publications. Tumor biobanks are an important source for these biospecimens and support both prospective and retrospective research studies. Supporting retrospective research requires tumor tissue biobanks to accrue an adequate inventory, or stock, of cases comprising tumor biospecimens and associated treatment and outcomes data. We propose a model to establish appropriate targets for stocks of frozen tissue biospecimens in tumor biobanks, sufficient to support cancer research needs. Our model considers national levels of investment in academic cancer research relative to research use of cases described in publication output, and scales this to the local context of the BC Cancer Agency Tumour Tissue Repository (TTR) as an example. Adjustment factors are then applied to correct for the primary intended user base of the biobank, as well as variables intrinsic to all biobanking operations and case collection. On this basis we estimate a current target stock for the TTR of approximately 4500 cases. Local research demand derived from case release data can then be applied to fine-tune accrual targets and refine the biobank's relative portfolio of cases from different tumor sites. We recognize that current targets will need regular remodeling as research demands change over time and that our initial model has some limitations related to the need to extrapolate from available research and biobank utilization data, and does not incorporate biospecimen/case contributions within the context of a network. However, we believe the lack of models to estimate inventory targets for tumor biobanks and to better balance research demand with biospecimen supply, contributes to the hesitation of funders to provide support, and also the problems of sustainability faced by many biobanks. Creating tangible inventory targets will improve biobank efficiency, sustainability, and may also encourage increased and stable funding.
The question of how best to attribute the unit costs of the annotated biospecimen product that is provided to a research user is a common issue for many biobanks. Some of the factors influencing user fees are capital and operating costs, internal and external demand and market competition, and moral standards that dictate that fees must have an ethical basis. It is therefore important to establish a transparent and accurate costing tool that can be utilized by biobanks and aid them in establishing biospecimen user fees. To address this issue, we built a biospecimen user fee calculator tool, accessible online at www.biobanking.org . The tool was built to allow input of: i) annual operating and capital costs; ii) costs categorized by the major core biobanking operations; iii) specimen products requested by a biobank user; and iv) services provided by the biobank beyond core operations (e.g., histology, tissue micro-array); as well as v) several user defined variables to allow the calculator to be adapted to different biobank operational designs. To establish default values for variables within the calculator, we first surveyed the members of the Canadian Tumour Repository Network (CTRNet) management committee. We then enrolled four different participants from CTRNet biobanks to test the hypothesis that the calculator tool could change approaches to user fees. Participants were first asked to estimate user fee pricing for three hypothetical user scenarios based on their biobanking experience (estimated pricing) and then to calculate fees for the same scenarios using the calculator tool (calculated pricing). Results demonstrated significant variation in estimated pricing that was reduced by calculated pricing, and that higher user fees are consistently derived when using the calculator. We conclude that adoption of this online calculator for user fee determination is an important first step towards harmonization and realistic user fees.
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Biospecimens are critical in driving health research. There is increased demand for scale and quality of biospecimens that in turn drives biobanking operational costs, influences utilization, and threatens the sustainability of individual biobanks. Biospecimen research has begun to inform the details of new biobanking standards and the steps of the biobanking process that are most important to focus on to achieve higher quality. This focus on quality is currently centered mostly on intrinsic features of biospecimens and their annotating data. This review highlights additional quality features that are important to researchers in determining the fit for purpose in their research. First, we define complex qualities as those that are mostly extrinsic to the individual biospecimen and data, and second, we provide data on the growth in demand for biospecimens with this type of quality in cancer research biobanks. Finally, we discuss why biospecimen complexity is a challenge for biobanks and utilization of existing collections, and provide examples of strategies biobanks can consider to improve their focus on this aspect of quality, as we predict that researcher demand for complex biospecimens will continue to expand in the future.
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