Jeff F. Dunn

Learn More
Identification of remyelination is important in the evaluation of potential treatments of demyelinating diseases such as multiple sclerosis. Local injection of lysolecithin into the brain or spinal cord provides a murine model of demyelination with spontaneous remyelination. The aim of this study was to determine if quantitative, multicomponent T(2) (qT(2))(More)
Primary glial tumors of the central nervous system, most commonly glioblastoma multiforme (GBM), are aggressive lesions with a dismal prognosis. Despite identification and isolation of human brain tumor stem cells (BTSCs), characteristics that distinguish BTSCs from neural stem cells remain to be elucidated. We cultured cells isolated from gliomas, using(More)
There is a need for acute and chronic stimulation of the brain within the MRI for studies of epilepsy, as well as deep brain stimulation for movement and behavioral disorders. This work describes the production and characteristics of carbon fiber-based electrodes for acute and chronic stimulation in the brain. Increasing MRI field strengths are making it(More)
An MRI method for quantification of cerebral blood volume (CBV) in time-course studies of angiogenesis is described. Angiogenesis was stimulated by acclimation to hypoxia. The change in relaxation rate, R2, which is relatively sensitive to the microvasculature, was quantified before and after infusion of a superparamagnetic vascular contrast agent (MION).(More)
Living related donor (LRD) nephrectomies are controversial due to the risks to the donor and improved cadaveric graft survival using cyclosporine A. Between December 22, 1970, and December 31, 1984, 1096 renal transplants were performed at a single institution, 314 (28.6%) from LRD. The average age was 34.3 years (range: 18-67); none had preoperative(More)
PURPOSE Whole-body vibrations are known to affect muscle activity and tissue oxygenation, but some energetic aspects are still poorly understood. This study investigates the effects of whole-body vibration on gastrocnemius muscle oxygen utilization rate and tissue oxygenation dynamics during exercise. METHODS The effects of vibration on gastrocnemius(More)
Typical quantitative T2 (qT2) analysis involves creating T2 distributions using a regularized algorithm from region-of-interest averaged decay data. This study uses qT2 analysis of simulated and experimental decay signals to determine how (a) noise-type, (b) regularization, and (c) region-of-interest versus multivoxel analyses affect T2 distributions. Our(More)
OBJECTIVE The purpose of our study was to describe the structural organization of the extracellular matrix of articular cartilage of the tibial plateau and its influence on MRI appearance. MATERIALS AND METHODS Spin-echo images of 11 resected tibial plateaus acquired at 7 T were compared with the structure of the extracellular matrix as shown by fracture(More)
MRI and histological studies have shown global alterations in iron levels in the brains of patients with multiple sclerosis (MS), including increases in the iron stored by macrophages and microglia. Excessive free iron can be toxic, and accumulation of iron in MS has generally been thought to be detrimental. However, iron maintains the integrity of(More)
PURPOSE To examine, using blood oxygen level dependent (BOLD) MRI and EPR oximetry, the changes in oxygenation of intracranial tumors induced by carbogen breathing. MATERIALS AND METHODS The 9L and CNS-1 intracranial rat tumor models were imaged at 7T, before and during carbogen breathing, using a multi-echo gradient-echo (GE) sequence to map R(2)*. On a(More)