Variability and symmetry of gait kinematics under dual-task performance of older patients with depression.

BACKGROUND: Depression in old age is associated with an increased fall risk. Especially in cognitively challenging situations, fall-promoting gait deviations could appear due to depression- and age-related cognitive deficits. AIM: This study investigates (i) whether there are differences in gait performance between depressed older patients and healthy controls and (ii) if gait patterns aggravate when performing a cognitive task whilst walking. METHODS: 16 depressed older patients (mean age: 73.1 ± 5.8 years) and 19 healthy controls (mean age: 73.3 ± 6.1 years) were included in the study. Spatiotemporal gait parameters (speed, stride length, swing time) and minimum toe clearance were recorded using a three-dimensional motion-capture system under a single- and a dual-task condition (counting backwards). RESULTS: After Bonferroni correction, depressed older patients showed significantly slower walking speed, shorter strides and smaller minimum toe clearance, as well as greater variability in stride length than healthy controls. Under the dual-task, gait performance deteriorated compared with single-task, with slower gait speed, shorter strides, and longer swing time. DISCUSSION: Slower walking speed and shorter steps of depressed patients may be a strategy to counteract their fall risk. Increased variability suggests a less stable gait pattern in patients, which could be a reason for their increased fall risk. CONCLUSIONS: Depression in old age has a strong effect on gait performance. Possible interventions that might prevent falls in this vulnerable group are discussed. The study was registered at Open Science Framework on May 18, 2021 (publicly accessible May 30, 2023).

Cryopreservation of red blood cells: Effect on rheologic properties and associated metabolic and nitric oxide related parameters.

AIM: High glycerol cryopreservation of red blood cells (RBCs) reduces metabolic processes at ultralow temperatures but less is known regarding the effect of cryopreservation on RBC nitric oxide (NO) metabolism, haemorheological properties, structural behaviour and membrane fragility. METHODS: Blood from ten healthy participants was sampled, glycerolized and stored at -80 °C (SB). Aliquots were thawed and further processed after 4, 8 and 12 weeks, respectively. At these time points, fresh blood (FB) was additionally sampled from each participant. FB/SB mixtures were prepared corresponding to transfusion of 1-3 blood bags. Additionally, mixtures were exposed to shear stress similar to that found in the circulation and deformability was measured to estimate possible behaviour of cryopreserved RBC in vivo. RESULTS: Ageing of RBC was reduced during cryopreservation. Markers for RBC metabolism (ATP, 2,3-DPG) were not altered but RBC sodium levels increased and potassium and calcium decreased, respectively. Mean cellular volume was higher and accordingly, mean cellular haemoglobin concentration was lower in SB. Deformability was altered during storage with less shear stress necessary to deform RBCs. Changes were also detectable in blood mixtures. Deformability remained unaltered in shear stress settings in FB and SB. RBC viscosity was reduced in SB. RBC-NOS content and phosphorylation sites as well as nitrite and RxNO levels seem not to be affected by the intervention. CONCLUSION: Cryopreservation maintains RBC metabolic function in vitro, but structure and function of cryopreserved RBC seems to be altered. Impact of these alterations in vivo seems to be less but needs further investigation.