Publications by authors named "Bret Holguin"

Alpha-synuclein seed amplification assays (αSyn-SAAs) are promising diagnostic tools for Parkinson's disease (PD) and related synucleinopathies. They enable detection of seeding-competent alpha-synuclein aggregates in living patients and have shown high diagnostic accuracy in several PD and other synucleinopathy patient cohorts. However, there has been confusion about αSyn-SAAs for their methodology, nomenclature, and relative accuracies when performed by various laboratories.

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The DARET (depolarization after resonance energy transfer) assay is a coupled Förster resonance energy transfer (FRET)-fluorescence polarization assay for botulinum neurotoxin type A or E (BoNT/A or BoNT/E) proteolytic activity that relies on a fully recombinant substrate. The substrate consists of blue fluorescent protein (BFP) and green fluorescent protein (GFP) flanking SNAP-25 (synaptosome-associated protein of 25 kDa) residues 134-206. In this assay, the substrate is excited with polarized light at 387 nm, which primarily excites the BFP, whereas emission from the GFP is monitored at 509 nm.

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Purpose: To screen superoxide dismutase 1 (SOD1) on chromosome 21 as a possible candidate gene for familial keratoconus (KC).

Methods: Total genomic DNA was extracted from the blood of 15 different KC families and 156 unaffected subjects. All five exons of the SOD1 gene were sequenced.

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Corneas with edema-related diseases lose transparency, which causes significant vision loss. This study analyzed seven aquaporins (AQPs) in normal corneas, pseudophakic/aphakic bullous keratopathy (PBK/ABK) corneas, Fuchs' dystrophy corneas, keratoconus corneas, post-cataract surgery (PCS) corneas, and normal organ-cultured corneas. RNA levels for AQP1, AQP4, and beta2-microglobulin were measured by RT-PCR.

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Purpose: To determine whether neuregulin 1 (Nrg-1) is expressed in the normal adult human cornea.

Methods: cDNA for Nrg-1 was obtained by direct amplification of RNA isolated from human corneal cell cultures. After sequencing, the likely exon/intron structure was determined by comparison to genomic sequence.

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