Diverse biophysical mechanisms in voltage-gated sodium channel Na1.4 variants associated with myotonia.

Mutations in SCN4A gene encoding Na1.4 channel α-subunit, are known to cause neuromuscular disorders such as myotonia or paralysis. Here, we study the effect of two amino acid replacements, K1302Q and G1306E, in the DIII-IV loop of the channel, corresponding to mutations found in patients with myotonia.

Fluorescence saturation imaging microscopy: molecular fingerprinting with a standard confocal microscope.

Molecular specificity in fluorescence imaging of cells and tissues can be increased by measuring parameters other than intensity. For instance, fluorescence lifetime imaging became a widespread modality for biomedical optics. Previously, we suggested using the fluorescence saturation effect at pulsed laser excitation to map the absorption cross-section as an additional molecular contrast in two-photon microscopy [Opt.

Excited States in Single-Stranded and i-Motif DNA with Silver Ions.

We have studied the excited states and structural properties for the complexes of cytosine (dC) chains with silver ions (Ag) in a wide range of the Ag to DNA ratio () and pH conditions using circular dichroism, steady-state absorption, and fluorescence spectroscopy along with the ultrafast fluorescence upconversion technique. We also calculated vertical electronic transition energies and determined the nature of the corresponding excited states in some models of the cytosine-Ag complexes. We show that (dC) chains in the presence of silver ions form a duplex stabilized by C-Ag-C bonds.

Mild phenotype of -associated congenital myasthenic syndrome: case series.

Congenital myasthenic syndrome with episodic apnea is associated with pathogenic variants in the gene. While respiratory disorders and oculomotor findings are commonly reported in affected individuals, a subset of patients only present with muscle weakness and/or ptosis but not apneic crises. In this case series, we describe five individuals with exercise intolerance caused by single nucleotide variants in the gene.