Acoustic radiation force impulse shear wave elastography quantifies upper limb muscle in patients with Duchenne muscular dystrophy.

We investigated whether the upper limb muscle stiffness quantified by the acoustic radiation force impulse shear wave elastography (ARFI/SWE) is a potential biomarker for age-related muscle alteration and functional decline in patients with Duchenne muscular dystrophy (DMD). 37 patients with DMD and 30 typically developing controls (TDC) were grouped by age (3-8, 9-11, and 12-18 years). ARFI/SWE measured the biceps and deltoid muscle's shear wave velocities (SWVs). Performance of Upper Limb Module (PUL 1.2 module) assessed muscle function in DMD patients. Mann Whitney test compared muscle SWVs between DMD and TDC, stratified by three age groups. We used analysis of variance with Bonferroni correction to compare muscle SWVs between DMD and TDC and correlated muscle SWVs with PUL results in the DMD group. Results showed that the SWVs of biceps differentiated DMD patients from TDC across age groups. Younger DMD patients (3-8 years) exhibited higher SWVs (p = 0.013), but older DMD patients (12-18 years) showed lower SWVS (p = 0.028) than same-aged TDC. DMD patients had decreasing biceps SWVs with age (p < 0.001), with no such age effect in TDC. The SWVs of deltoid and biceps positively correlated with PUL scores (r = 0.527 âˆ¼ 0.897, P < 0.05) and negatively correlated with PUL timed measures (r = -0.425 âˆ¼ -0.542, P < 0.05) in DMD patients. Our findings suggest that ARFI/SWE quantifying the SWVs in upper limb muscle could be a potential biomarker to differentiate DMD from TDC across ages and that DMD patients showed age-related muscle alteration and limb functional decline.

Sex identification of owls (family Strigidae) using oligonucleotide microarrays.

Molecular sexing of the diversified avian family Strigidae is difficult. Sex identification using the intron length difference between W and Z chromosomal CHD1 genes, as visualized by agarose gel electrophoreses, often produces ambiguous results. Here we describe a simple method for sexing a variety of Strigidae species using oligonucleotide microarrays, on which several sex-specific probes operated complementarily or in concert. The sex of 8 owl species was identified clearly on the microarrays through sequence recognition. This sequence-directed method can be easily applied to a wider range of Strigidae species.

Sexing a wider range of avian species based on two CHD1 introns with a unified reaction condition.

Identifying the sex of a bird is important to ensure successful breeding strategies and effective conservation programs. Sex may be identified from the intron size of the CHD1 gene located on the avian sex chromosomes Z and W. However, because of the great nucleotide diversity across different avian species, no given intron is in widespread use without ambiguous results. Complicated modifications of the reaction condition are required to suit different species. Two CHD1 introns were used with a unified reaction condition in this study to simplify the procedure. Consequently, genders of 73 avian species covering 19 families were successfully identified based on this two-intron approach. This means the ability to sex a wider range of avian species using a simplified procedure, greatly assisting in population management at zoos. Zoo Biol 26:425-431, 2007. (c) 2007 Wiley-Liss, Inc.