Cav3 T-type calcium channels from great pond snail Lymnaea stagnalis have a selectivity-filter ring of five acidic residues, EE(D)DD. Splice variants with exons 12b or 12a spanning the extracellular loop between the outer helix IIS5 and membrane-descending pore helix IIP1 (IIS5-P1) in Domain II of the pore module possess calcium selectivity or dominant sodium permeability, respectively. Here, we use AlphaFold2 neural network software to predict that a lysine residue in exon 12a is salt-bridged to the aspartate residue immediately C terminal to the second-domain glutamate in the selectivity filter.
View Article and Find Full Text PDFObjective: The objective of this study was to evaluate the construct validity of 2 health utility instruments-the EuroQoL-5 Dimension (EQ-5D) and the Health Utilities Index-Mark 3 (HUI-3)-and to compare them with disease-specific measures in patients with head and neck cancer.
Study Design: Prospective cross-sectional analysis.
Setting: Princess Margaret Cancer Centre.
Invertebrate LCa3 shares the quintessential features of vertebrate Ca3 T-type channels, with a low threshold of channel activation, rapid activation and inactivation kinetics and slow deactivation kinetics compared to other known Ca channels, the Ca1 and Ca2 channels. Unlike the vertebrates though, Ca3 T-type channels in non-cnidarian invertebrates possess an alternative exon 12 spanning the D2L5 extracellular loop, which alters the invertebrate LCa3 channel into a higher Na and lower Ca current passing channel, more resembling a classical Na1 Na channel. Cnidarian Ca3 T-type channels can possess genes with alternative cysteine-rich, D4L6 extracellular loops in a manner reminiscent of the alternative cysteine-rich, D2L5 extracellular loops of non-cnidarian invertebrates.
View Article and Find Full Text PDFBackground: We sought to develop mapping functions that use EORTC responses to approximate health utility (HU) scores for patients with head and neck cancer (HNC).
Methods: In total, 209 outpatients with HNC completed the EORTC QLQ-C30 & QLQ-H&N35 (EORTC), EQ-5D-5L and the HUI-3. Results of the EORTC were mapped onto both EQ-5D-5L and HUI-3 scores using ordinary least squares regression and two-part models.
Background: There is no mechanism to predict health utility (HU) values from the University of Washington Quality of Life Questionnaire (UWQoL) scores. We sought to develop a mapping algorithm capable of using UWQoL data to approximate HU scores.
Methods: Outpatients with head and neck cancer completed the UWQoL, EQ-5D, and the Health Utilities Index-Mark 3 (HUI-3).
Purpose To evaluate acute and late genitourinary (GU) and gastrointestinal (GI) toxicity and the biochemical control of pure hypofractionated radiotherapy (without acceleration) for the treatment of prostate cancer. Methods and materials This phase II prospective trial evaluated low-risk and intermediate-risk prostate cancer patients who received hypofractionated radiotherapy. Fifty-three patients with low-risk prostate cancer received 50 Gy in 15 fractions, 156 patients with intermediate-risk prostate cancer received 60 Gy in 20 fractions over eight weeks.
View Article and Find Full Text PDFCalcium (Ca1 and Ca2) and sodium channels possess homologous CaM-binding motifs, known as IQ motifs in their C termini, which associate with calmodulin (CaM), a universal calcium sensor. Ca3 T-type channels, which serve as pacemakers of the mammalian brain and heart, lack a C-terminal IQ motif. We illustrate that T-type channels associate with CaM using co-immunoprecipitation experiments and single particle cryo-electron microscopy.
View Article and Find Full Text PDFHow nature discriminates sodium from calcium ions in eukaryotic channels has been difficult to resolve because they contain four homologous, but markedly different repeat domains. We glean clues from analyzing the changing pore region in sodium, calcium and NALCN channels, from single-cell eukaryotes to mammals. Alternative splicing in invertebrate homologs provides insights into different structural features underlying calcium and sodium selectivity.
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