Evaluation of maximal exercise capacity through the incremental shuttle walking test in lymphangioleiomyomatosis.

BACKGROUND: The cardiopulmonary exercise test (CPET) is the gold standard for assessing aerobic fitness; however, it is expensive, not widely available, and requires specialized equipment and staff. The incremental shuttle walking test (ISWT) is an exercise field test used to evaluate exercise capacity and may be an alternative to CPET in patients with lymphangioleiomyomatosis (LAM). OBJECTIVE: To investigate whether the ISWT can be used to assess maximal aerobic capacity in patients with LAM. METHODS: Forty-five women were evaluated on two days, and they randomly performed the CPET and ISWT. The maximum oxygen uptake (peak VO2) was evaluated using gas analyzers in both tests. The carbon dioxide production (VCO2), respiratory exchange ratio (RER), and heart rate (HR) were compared during peak exercise. Pearson's correlation and Bland-Altman assessed the association and agreement, respectively. The intraclass correlation coefficient (ICC) was used to assess the reliability of the data. RESULTS: All patients (46.1 ± 10.2 years) presented similar peak VO2, RER, and peak HR during the CPET and ISWT (15.6 ± 4.6 vs. 15.7 ± 4.4 ml·kg-1·min-1; 1.15±0.09 vs. 1.17±0.12; and 142.2 ± 18.6 vs. 141.5 ± 22.2 bpm, respectively; p>0.05). A good linear correlation (r = 0.79; p<0.001) and ICC (0.86; 95%CI 0.74-0.93) were observed between the peak VO2 in both tests. Predictive peak VO2 equations based on the ISWT performance are also presented. CONCLUSION: Our results suggest that the ISWT can be used to assess maximal exercise performance in patients with LAM, and it is a valuable option to be used as an alternative to the CPET and predict maximal exercise capacity.

High levels of genetic diversity throughout the range of the Portuguese wheat landrace 'Barbela'.

BACKGROUND AND AIMS: Landrace populations represent an important intra-crop reservoir of biodiversity and source of novel gene alleles for use in breeding programmes. Here the aim was to measure the diversity of a wheat landrace, 'Barbela', from the north of Portugal. METHODS: DNA was extracted from 59 accessions of Barbela collected across its geographical range. Diversity was measured by microsatellite length polymorphisms using 27 primer pairs amplifying 34 polymorphic microsatellite loci. KEY RESULTS: High levels of polymorphism were found, with an average polymorphism information content of 0.52; an average of 4.77 alleles (range 2-11) were present at each locus, and half of these loci showed an additional allele in the reference variety 'Chinese Spring'. CONCLUSIONS: 'Barbela' is maintained from seeds collected by farmers, but it maintains high allelic variation, and no groupings of accessions were detected when analysed by geographical region, farm or climate, indicating that the wheat landrace is a homogeneous entity. The diversity within the farmer-maintained landrace demonstrates the importance of characterization and maintenance of landrace collections before valuable genetic combinations are lost as uniform commercial crops are introduced.

Introgression of rye chromatin on chromosome 2D in the Portuguese wheat landrace 'Barbela.'.

The old Portuguese wheat landrace aggregate known as 'Barbela' shows good productivity under the low-fertility conditions often associated with acid soils. The use of genomic rye DNA, in combination with 45S rDNA and the repetitive sequences dpTal and pScl 19.2 as probes, in two sequential in situ hybridization steps enabled the identification of all chromosomes in the 'Barbela' wheat lines and the detection of the introgression of rye-origin chromatin onto wheat chromosome arm 2DL in two of the lines. Amplification of microsatellite loci using published primer pairs showed that the distal segment of wheat chromosome 2DL, which was involved in the rye translocation, was deleted. The identification and characterization of small recombinant chromosome segments in wheat-rye lines may allow their use in plant breeding programmes. Their presence in farmer-maintained material demonstrates the importance of maintaining, characterizing, and collecting landrace material before valuable genetic combinations are lost as uniform commercial crops are introduced.