Robert A. Allen

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Host remodeling is important for the success of medical implants, including vascular substitutes. Synthetic and tissue-engineered grafts have yet to show clinical effectiveness in arteries smaller than 5 mm in diameter. We designed cell-free biodegradable elastomeric grafts that degrade rapidly to yield neoarteries nearly free of foreign materials 3 months(More)
OBJECTIVES To describe the prevalence of cobalamin (Cbl) deficiency in older adult outpatients and to determine whether regular intake of a synthetic source of cobalamin confers protection against Cbl deficiency. DESIGN Cross-sectional study. SETTING Two university-affiliated geriatric medicine outpatient clinics. PARTICIPANTS Three hundred fifteen(More)
Transplantation of functional adrenal cortex cells could reduce morbidity and increase the quality of life of patients with adrenal insufficiency. Our aim was to determine whether adrenal extracellular matrix (ECM) scaffolds promote adrenocortical cell endocrine function and proliferation in vitro. We seeded decellularized porcine adrenal ECM with primary(More)
Kerions result from a massive delayed-type hypersensitivity reaction to a dermatophyte. Treatment traditionally has been directed primarily toward the dermatophyte. The authors propose, however, that inflammation should be the initial target oftreatment. Clinical findings and treatment outcomes for two patients with kerions, treated with short courses of(More)
The objective of this study was to evaluate the long-term performance of cell-free vascular grafts made from a fast-degrading elastic polymer. We fabricated small arterial grafts from microporous tubes of poly(glycerol sebacate) (PGS) reinforced with polycaprolactone (PCL) nanofibers on the outer surface. Grafts were interpositioned in rat abdominal aortas(More)
The foundational structure of a new model of user perception of computer system response time is proposed. It is suggested that the development of such a model is now of central importance to the computer system configuration design effort. The new model is seen to explain the success of an earlier measure, designed for the non-interactive environment, in(More)
Bone marrow-derived progenitor cells are promising cell sources for vascular tissue engineering. However, conventional bone marrow mesenchymal stem cell expansion and induction strategies require plating on tissue culture plastic, a stiff substrate that may itself influence cell differentiation. Direct scaffold seeding avoids plating on plastic; to the best(More)
Poly(glycerol sebacate) (PGS) is a thermally-crosslinked elastomer suitable for tissue regeneration due to its elasticity, degradability, and pro-regenerative inflammatory response. Pores in PGS scaffolds are typically introduced by porogen leaching, which compromises strength. Methods for producing fibrous PGS scaffolds are very limited. Electrospinning is(More)
Many surgical interventions for cardiovascular disease are limited by the availability of autologous vessels or suboptimal performance of prosthetic materials. Tissue engineered vascular grafts show significant promise, but have yet to achieve clinical efficacy in small caliber (<5 mm) arterial applications. We previously designed cell-free elastomeric(More)