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C Miller

Publications and source records attributed to C Miller.

At least 451 records · Page 25Linked to original sources
PubMed1991

Reduce chance of exposure.

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Centers for Disease Control and Prevention, U.S.↗
PubMed1991

CDC updates guidelines.

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Centers for Disease Control and Prevention, U.S.↗
PubMed1991

Guarding against HIV.

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Acquired Immunodeficiency Syndrome↗
PubMed1990

Molecular structure of charybdotoxin, a pore-directed inhibitor of potassium ion channels.

The three-dimensional structure of charybdotoxin, a high-affinity peptide blocker of several potassium ion channels, was determined by two-dimensional nuclear magnetic resonance (2-D NMR) spectroscopy. Unambiguous NMR assignments of backbone and side chain hydrogens were made for all 37 amino acids. The structure was determined by distance geometry and refined by nuclear Overhauser and exchange spectroscopy back calculation. The peptide is built on a foundation of three antiparallel beta strands to which other parts of the sequence are attached by three disulfide bridges. The overall shape is roughly ellipsoidal, with axes of approximately 2.5 and 1.5 nanometers. Nine of the ten charged groups are located on one side of the ellipsoid, with seven of the eight positive residues lying in a stripe 2.5 nanometers in length. The other side displays three hydrophobic residues projecting prominently into aqueous solution. The structure rationalizes several mechanistic features of charybdotoxin block of the high-conductance Ca2(+)-activated K+ channel.

Amino Acid Sequence↗
PubMed1990

Radiotherapy of retinoblastoma. A review of 63 children treated with different irradiation techniques.

This is a retrospective review of treatment results in 63 children with retinoblastoma (RB) who received therapeutic irradiation from January 1975 to June 1988. Patient ages ranged from birth to 5 years with a mean age of 12.5 months. Three treatment groups were identified. In Group A, episcleral plaque was the only irradiation modality. In this group, 24 patients and 25 eyes with tumors of Reese-Ellsworth Stages I to III, and selected Stage VB tumors were irradiated using eye plaques. Twenty-two of 25 (88%) eyes are without evidence of disease (NED), and all patients are alive. Two eyes were enucleated for recurrent RB. Two of 23 eyes developed minimal cataracts. In Group B, external-beam was the only irradiation modality. Twelve patients with 21 involved eyes comprise this group. Thirteen eyes received EBRT alone. Seventy-seven percent of 13 eyes have NED. Four eyes developed cataracts. Three of 13 eyes required enucleation for progression of disease; one of these was Stage IVA and two of them were Stage VA. For Group C, external-beam plus episcleral plaque was used. Twenty-seven patients and 51 eyes with advanced retinoblastoma were included in this group. Episcleral plaque was used in 29 eyes as a salvage procedure for recurrent RB, or in selected cases was used as a boost after initial external beam irradiation. Fifteen of 29 eyes (52%) remain with NED with useful vision, and nine developed cataracts. Enucleation was performed in 14 eyes for recurrent RB. The authors conclude that radiation therapy has a major role in the management of RB due to its ability to control even advanced disease, allowing preservation of vision in a significant number of patients.

Cataract↗
PubMed1990

Diffusion-controlled binding of a peptide neurotoxin to its K+ channel receptor.

Single Ca2(+)-activated K+ channels were reconstituted into planar lipid bilayer membranes, and the effect of charybdotoxin, a pore-blocking peptide from scorpion venom, was studied. In particular, the effect of solution viscosity on the kinetics of block was assessed in order to test the idea that toxin binding is diffusion-controlled. This idea is supported by the strictly inverse relation between solution viscosity and the rate constants of both association and dissociation of peptide with the K+ channel mouth. However, at an ionic strength high enough to suppress local electrostatic potentials, the diffusion-controlled on-rate constant is surprisingly low, 10(5) M-1 s-1. These slow, viscosity-dependent kinetics may be understood if charybdotoxin can attain the bound state only from a rare set of encounters with the K+ channel.

Animals↗
PubMed1990

Steady-state coupling of ion-channel conformations to a transmembrane ion gradient.

Under stationary conditions, opening and closing of single Torpedo electroplax chloride channels show that the number of transitions per unit time between inactivated and conducting states are unequal in opposite directions. This asymmetry, which increases with transmembrane electrochemical gradient for the chloride ion, violates the principle of microscopic reversibility and thus demonstrates that the channel-gating process is not at thermodynamic equilibrium. The results imply that the channel's conformational states are coupled to the transmembrane electrochemical gradient of the chloride ion.

Animals↗