Medicine and Health Sciences Commons^™

Impaired Fast-Spiking, Suppressed Cortical Inhibition, And Increased Susceptibility To Seizures In Mice Lacking Kv3.2 K+ Channel Proteins, David Lau, Eleazar Vega-Saenz De Miera, Diego Contreras, Alan Chow, Richard Paylor, Christopher S. Leonard, Bernardo Rudy

NYMC Faculty Publications

Voltage-gated K(+) channels of the Kv3 subfamily have unusual electrophysiological properties, including activation at very depolarized voltages (positive to -10 mV) and very fast deactivation rates, suggesting special roles in neuronal excitability. In the brain, Kv3 channels are prominently expressed in select neuronal populations, which include fast-spiking (FS) GABAergic interneurons of the neocortex, hippocampus, and caudate, as well as other high-frequency firing neurons. Although evidence points to a key role in high-frequency firing, a definitive understanding of the function of these channels has been hampered by a lack of selective pharmacological tools. We therefore generated mouse lines in which one …

Chronic Hypoxia, Exercise Training, And Skeletal Muscle Capillarity: Angiogenic Regulation And Morphological Consequences, Ivan Mark Olfert

Loma Linda University Electronic Theses, Dissertations & Projects

Angiogenesis is important in health and disease. In particular, exercise training is known to increase skeletal muscle capillarity, providing there is sufficient training intensity. The stimulus for this may be intracellular hypoxia activating angiogenic growth factor gene expression. Acute hypoxia alone has been shown to increase the gene expression of several key angiogenic regulators, e.g. vascular endothelial growth factor (VEGF) and to a lesser degree transforming growth factor-β1 (TGF-β1), basic fibroblast growth factor (bFGF), and thrombospondin-1 (TSP-1), an endogenous negative angiogenic regulator. Paradoxically, however, chronic hypoxia is generally not found to increase mammalian skeletal muscle capillarity. Accordingly, we hypothesized that …

Method And Apparatus For Adaptive Filtering By Counting Acoustic Sample Zeroes In Ultrasound Imaging, Gregory R. Bashford, Edward D. Nonnweiler, David D. Becker, David John Muzilla

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasound imaging system having an adaptive spatial filter the filter coefficients of which, for particular image parameter sample, are determined by counting the number of neighboring image parameter samples having zero or near-zero values. If the number of zero or near-zero values in a data window is greater than a predetermined threshold, the data in the window is passed, not filtered. This filter has two advantages over other spatial filters. First, image parameter data samples having only zero or near-zero neighboring values (i.e., isolated "point noise") are not smeared. Second, boundaries such as the edge of color in a …

Interactions Of Igf-Ii And Cathepsin D In Mcf-7 Breast Cancer Cells, Jesika S. Faridi

Loma Linda University Electronic Theses, Dissertations & Projects

A primary role of the IGF-II/M6P receptor is to target lysosomal enzymes from the golgi to the lysosomes. This receptor has distinct binding sites for IGF-II and M6P, however, reciprocal interactions between these ligands have been observed (Kiess et al. 1989, 1990). Since IGF-II modulates the routing of cathepsin D in MCF-7 cells by blocking the intracellular binding of cathepsin D to the IGF-II/M6P receptor (De León et al. 1996), we hypothesized that expressing a mutant form of IGF-II that does not bind the IGF-II/M6P receptor will not interfere with lysosomal enzyme trafficking.

In our present study, we report the …

Role Of Lipolysis And Lipogenesis In The Development Of Diet-Induced Obesity, Michael John Davies

Theses and Dissertations in Biomedical Sciences

Obesity is an increasingly common public health problem with approximately one-half of the American adult population overweight and one-quarter considered obese. This alarming trend has led researchers to determine potential causative factors of excess weight gain in humans. However, it is difficult to discern whether perturbations that result in obesity are the cause or simply the result of the obese state. Diet-induced obesity is one of the animal models that allow researchers to address temporal issues. Our laboratory utilizes a diet-induced obesity model in which Sprague-Dawley rats are placed on a purified moderately high fat diet and ultimately diverge into …

An Ultrastructural Survey Of The Nuchal Glands Of Rhabdophis Tigrinus (Serpentes: Colubridae), Kathleen A. Roberts

Biological Sciences Theses & Dissertations

Rhabdophis tigrinus, an Asian natricine snake, possesses a series of integumentary glands located in the nuchal skin. Previous studies indicated that the nuchal glands are of mesodermal origin, contain cardiac steroids analogous to bufotoxins found in the parotoid glands of toads, which are included in the snake's diet. The nuchal glands are defensive in function. Preliminary histological studies revealed differences in quality of the gland tissue compared to previous studies, and difference in fixation techniques were suspected. Seven specimens of R. tigrinus were fixed by perfusion using a conservative fixation process standard for electron microscopy. The nuchal gland series …

Method And Apparatus For Controlling Acoustic Signal Bandwidth In An Ultrasonic Diagnostic Imaging System, Jeffrey R. Resnick, Gregory R. Bashford

Biomedical Imaging and Biosignal Analysis Laboratory

An ultrasonic imaging system includes a receive beamformer that generates analog receive signals and a scan converter. A receive signal processing path interconnects the receive beamformer and the scan converter, and this processing path included both an A/D converter characterized by a selectable sampling rate and at least one filter characterized by at least one filter parameter. The filter parameter is selected as a function of the sampling rate to provide enhanced image quality.

Expression And Requirement Of Epithelial Fatty Acid- Binding Protein In Neuronal Axon Growth, Gregory William Allen

Loma Linda University Electronic Theses, Dissertations & Projects

Epithelial fatty acid-binding protein (E-FABP) is expressed in the dorsal root ganglia following sciatic nerve injury and in migrating and differentiating neurons during neuronal development. It was hypothesized that E-FABP expression is required for the robust outgrowth of axons from developing and regenerating neurons. To test this hypothesis, E-FABP expression in both PC12 cells and primary retinal neurons was examined. In PC12 cells, NGF induces E-FABP mRNA and protein during the period of neurite outgrowth, and E-FABP localizes to the perinuclear cytoplasm, nucleus, and growth cone. Furthermore, E-FABP-deficient cell lines exposed to NGF were less differentiated and had shorter neurites …

Method And Apparatus For Three-Dimensional Ultrasound Imaging Of Biopsy Needle, Syed Omar Ishrak, Mir Said Seyed-Bolorforosh, William Thomas Hatfield, Todd Michael Tillman, Brian Peter Geiser, Gregory R. Bashford, Michael Joseph Washburn

Biomedical Imaging and Biosignal Analysis Laboratory

A method and an apparatus for three-dimensional ultrasound imaging of a needle-like instrument, such as a biopsy needle, inserted in a human body. The instrument is visualized by transmitting ultrasound beams toward the instrument and then detecting the echo signals using a linear array of transducer elements. The problem of ultrasound being reflected from a biopsy needle in a direction away from the transducer array is solved by steering the transmitted ultrasound beams t increase the angle at which the beams impinge upon the biopsy needle. Ideally the ultrasound beams are perpendicular to the needle. This increases the system's sensitivity …

Client-Centered Versus Traditional-Directive Educational Approach: A Randomized Study Of Exercises And Perceived Control Among Patients With Type 2 Diabetes, Melissa D. Olfert

Loma Linda University Electronic Theses, Dissertations & Projects

A patient’s adherence to self-management therapies in diabetes strongly influences health outcomes, health care utilization, and ultimately health care costs. Engaging in regular exercise therapy reduces risk factors associated with type 2 diabetes. The purpose of this randomized prospective study was to determine if a client-centered approach (CCA) toward diabetes education, verses a traditional-directive approach (TDA), would improve exercise participation, perceived control, intention to exercise, and glycemic control in patients with type 2 diabetes.

Fifty-nine type 2 patients were randomized into two groups: CCA and TDA. Diabetes education in the CCA group provided empowerment toward acquiring knowledge, skills, and responsibility …