Prescribing and adjusting exercise training in chronic respiratory diseases – Expert-based practical recommendations

Background International guidelines recommend endurance (ET) and strength training (ST) in patients with chronic respiratory diseases (CRDs), but only provide rough guidance on how to set the initial training load. This may unintentionally lead to practice variation and inadequate training load adjustments. This study aimed to develop practical recommendations on tailoring ET and ST based on practices from international experts from the field of exercise training in CRDs. Methods 35 experts were invited to address a 64-item online survey about how they prescribe and adjust exercise training. Results Cycling (97%) and walking (86%) were the most commonly implemented ET modalities. Continuous endurance training (CET, 83%) and interval endurance training (IET, 86%) were the frequently applied ET types. Criteria to prescribe IET instead of CET were: patients do not tolerate CET due to dyspnoea at the initial training session (79%), intense breathlessness during initial exercise assessment (76%), and/or profound exercise-induced oxygen desaturation (59%). For ST, most experts (68%) recommend 3 sets per exercise; 62% of experts set the intensity at a specific load that patients can tolerate for a range of 8 to 15 repetitions per set. Also, 56% of experts advise patients to approach local muscular exhaustion at the end of a single ST set. Conclusions The experts´ practices were summarized to develop practical recommendations in the form of flowcharts on how experts apply and adjust CET, IET, and ST in patients with CRDs. These recommendations may guide health care professionals to optimize exercise training programs in patients with CRDs

Characterization of a unique Caulobacter crescentus aldose-aldose oxidoreductase having dual activities

We describe here the characterization of a novel enzyme called aldose-aldose oxidoreductase (Cc AAOR; EC 1.1.99) from Caulobacter crescentus. The Cc AAOR exists in solution as a dimer, belongs to the Gfo/Idh/MocA family and shows homology with the glucose-fructose oxidoreductase from Zymomonas mobilis. However, unlike other known members of this protein family, Cc AAOR is specific for aldose sugars and can be in the same catalytic cycle both oxidise and reduce a panel of monosaccharides at the C1 position, producing in each case the corresponding aldonolactone and alditol, respectively. Cc AAOR contains a tightly-bound nicotinamide cofactor, which is regenerated in this oxidation-reduction cycle. The highest oxidation activity was detected on d-glucose but significant activity was also observed on d-xylose, l-arabinose and d-galactose, revealing that both hexose and pentose sugars are accepted as substrates by Cc AAOR. The configuration at the C2 and C3 positions of the saccharides was shown to be especially important for the substrate binding. Interestingly, besides monosaccharides, Cc AAOR can also oxidise a range of 1,4-linked oligosaccharides having aldose unit at the reducing end, such as lactose, malto- and cello-oligosaccharides as well as xylotetraose. 1H NMR used to monitor the oxidation and reduction reaction simultaneously, demonstrated that although d-glucose has the highest affinity and is also oxidised most efficiently by Cc AAOR, the reduction of d-glucose is clearly not as efficient. For the overall reaction catalysed by Cc AAOR, the l-arabinose, d-xylose and d-galactose were the most potent substrates