Daniel Levy

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Extracellular potassium modulates recovery from C-type inactivation of Kv1.3 in human T lymphocytes. The results of whole-cell patch clamp recordings show that there is a linear increase in recovery rate with increasing [K+]o. An increase from 5 to 150 mM K+o causes a sixfold acceleration of recovery rate at a holding potential of -90 mV. Our results(More)
We used patch clamp techniques to identify and characterize a variety of K+ channels in primary human peripheral T lymphocytes. The most common channel observed in cell-attached configuration was voltage gated and inactivating. In ensemble averages, the kinetics of its activation and inactivation were similar to those of the whole-cell, voltage-gated K+(More)
Activation of N-methyl-D-aspartate (NMDA) receptors is thought to mediate toxic damage to central neurons due to hypoxia-ischemia, hypoglycemia, and trauma. We studied identified rat retinal ganglion cell neurons in vitro, a useful system for the study of excitotoxicity, and compared the protective effects of delayed administration of a competitive(More)
Acute neurological injury from hypoxia-ischemia, hypoglycemia, and trauma is thought to be predominantly mediated by activation of the N-methyl-D-aspartate (NMDA) subtype of glutamate receptor in the brain and the subsequent influx of calcium ions through receptor-operated channels. Several chronic degenerative diseases, such as Huntington's disease and the(More)
Recovery from C-type inactivation of Kv1.3 can be accelerated by the binding of extracellular potassium to the channel in a voltage-dependent fashion. Whole-cell patch-clamp recordings of human T lymphocytes show that Ko+ can bind to open or inactivated channels. Recovery is biphasic with time constants that depend on the holding potential. Recovery is also(More)
OBJECT The authors studied the relationships between tumor size, location, and topographic position relative to the intact facial nerve bundles in acoustic neurinomas to determine the influence of these factors on hearing preservation postoperatively. Consistent topographic relationships were found. METHODS Four hundred fifty-two patients with acoustic(More)
A retrospective study of external lumbar subarachnoid drainage in 16 pediatric patients with severe head injuries is presented. All patients had Glasgow Coma Scale scores of 8 or lower at 6 hours postinjury and were initially treated with ventriculostomy. Five patients required surgical evacuation of focal mass lesions. All patients manifested high(More)
Appropriately sized 0.010- and 0.018-inch complex framing coils were placed in a wide-necked silicone aneurysm replica, and their stability was evaluated at variable physiologic flow rates using video recording. After detachment, the 0.010-inch coils demonstrated instability/prolapse that was proportional to flow rate. In contrast, 0.018-inch coils held(More)
Locomotor stepping in the Nembutal-anesthetized rat was elicited by electrical stimulation of either of two sites in the right or left posterolateral hypothalamus. Essential midbrain loci were identified by reversibly blocking the elicited locomotion through local injections of the anesthetic procaine (15%, 0.5 microliter). Two types of critical midbrain(More)
N-methyl-D-aspartate(NMDA) antagonists afford possible therapeutic modalities for stroke, trauma, and various neurodegenerative conditions thought to be mediated by excessive stimulation of NMDA receptors in the brain. To date, however, no drug has been demonstrated to be a safe NMDA antagonist at a dosage necessary for neuroprotection. In the present(More)