John L Parker

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Electrical stimulation of the spinal cord provides effective pain relief to hundreds of thousands of chronic neuropathic pain sufferers. The therapy involves implantation of an electrode array into the epidural space of the subject and then stimulation of the dorsal column with electrical pulses. The stimulation depolarises axons and generates propagating(More)
The pathophysiology of periventricular lucency (PVL) on CT in primates was evaluated by transmission (TEM) and scanning electron microscopy (SEM). At 100 days after Silastic-induced hydrocephalus, six primate brains showed loss of cilia and ependymal cells over the ventricular surface and abnormal small supraependymal cells. TEM demonstrated communicating(More)
Ten peanut-sensitive patients were enrolled in a double-blind crossover trial to determine whether ingestion of peanut oil can induce adverse reactions in such individuals. All patients had experienced prior allergic reactions to peanut ingestion, including any of the following: generalized urticaria, angioedema, abdominal cramps, vomiting, diarrhea,(More)
We have previously isolated a purified Alternaria fraction (Alt-I) by means of immunochemical (RAST) assays to document allergenicity. In the present study we investigated the allergenicity of Alt-I by in vivo and in vitro biologic tests in a selected group of 16 nonimmunized Alternaria-sensitive patients, all of whom had positive skin tests to crude(More)
We report the case of a patient with anaphylaxis after ingestion of millet seeds, a previously unreported allergen. Skin testing with freshly prepared millet seed extract produced positive intradermal responses at a concentration of 100 pg/ml. The reaction was mediated by IgE antibodies to millet, as demonstrated by elevated specific IgE antibody levels by(More)
OBJECTIVES The study aims to characterize the electrical response of dorsal column axons to depolarizing stimuli to help understand the mechanisms of spinal cord stimulation (SCS) for the relief of chronic pain. MATERIALS AND METHODS We recorded electrically evoked compound action potentials (ECAPs) during SCS in 10 anesthetized sheep using stimulating(More)
OBJECTIVE Deep brain stimulation (DBS) has become the standard treatment for advanced stages of Parkinson's disease (PD) and other motor disorders. Although the surgical procedure has improved in accuracy over the years thanks to imaging and microelectrode recordings, the underlying principles that render DBS effective are still debated today. The aim of(More)