Rapid, inexpensive scanning for all possible BRCA1 and BRCA2 gene sequence variants in a single assay: implications for genetic testing.
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Biomedical subjects
Publications and source records attributed to D Rines.
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Two-dimensional gene scanning (TDGS) is a method for analyzing multiple DNA fragments in parallel for all possible sequence variations, using extensive multiplex PCR and two-dimensional electrophoretic separation on the basis of size and melting temperature. High throughput application of TDGS is limited by the prolonged time periods necessary to complete the second-dimension electrophoretic separation step--denaturing gradient gel electrophoresis--and the current need for gel staining. To address these problems, we constructed a high-voltage, automatic, two-dimensional electrophoresis system and used this in combination with thinner gels to reduce two-dimensional electrophoresis time about 80%. Instead of gel staining, we used three different fluorophores to simultaneously analyze three samples in the same gel. These improvements greatly increase TDGS speed and throughput and make the method highly suitable for large-scale single-nucleotide polymorphism discovery and genetic testing.
This study was designed to investigate the reliability of real-ear measurements of sound pressure level (SPL) and to compare these values with two coupler measures of SPL. A commercially available probe tube microphone system was used to measure real ear SPL in both children and adults. Test-retest reliability decreased as a function of frequency for both groups and, in general, was slightly poorer for the children. For both groups, coupler to real ear differences were larger for the 2 cm3 coupler than for the reduced volume coupler; however, no significant differences were observed between groups. In addition, a measure of ear canal volume was not found to be a good predictor of coupler to real ear discrepancies.
The functional gain of a hearing aid typically is determined by comparing aided and unaided behavioral thresholds. With this method, however, true gain may be underestimated in frequency regions of normal or near-normal hearing sensitivity (i.e., in cases of sloping, rising, or trough-shaped audiograms). Internal hearing-aid noise and/or amplified room noise imposes a lower limit on obtainable aided thresholds. In these cases, comparing aided and unaided acoustic-reflex thresholds may be a valuable clinical alternative to traditional means of determining real-ear gain. This study compared sound-field behavioral threshold and acoustic-reflex threshold estimates of functional gain for individuals with a variety of audiometric configurations. The sound-field behavioral threshold measurements were found to underestimate functional gain if unaided thresholds approached the normal hearing range. In regions of greater hearing loss, behavioral and acoustic-reflex estimates of functional gain were in good agreement.