Physical therapy interventions for older people with vertigo, dizziness and balance disorders addressing mobility and participation: a systematic review.

BACKGROUND: Vertigo, dizziness and balance disorders (VDB) are among the most relevant contributors to the burden of disability among older adults living in the community and associated with immobility, limitations of activities of daily living and decreased participation. The aim of this study was to identify the quality of evidence of physical therapy interventions that address mobility and participation in older patients with VDB and to characterize the used primary and secondary outcomes. METHODS: A systematic search via MEDLINE (PubMed), Cochrane Library, CINAHL, PEDro, forward citation tracing and hand search was conducted initially in 11/2017 and updated in 7/2019. We included individual and cluster-randomized controlled trials and trials with quasi-experimental design, published between 2007 and 2017/2019 and including individuals ≥65 years with VDB. Physical therapy and related interventions were reviewed with no restrictions to outcome measurement. Screening of titles, abstracts and full texts, data extraction and critical appraisal was conducted by two independent researchers. The included studies were heterogeneous in terms of interventions and outcome measures. Therefore, a narrative synthesis was conducted. RESULTS: A total of 20 randomized and 2 non-randomized controlled trials with 1876 patients met the inclusion criteria. The included studies were heterogeneous in terms of complexity of interventions, outcome measures and methodological quality. Vestibular rehabilitation (VR) was examined in twelve studies, computer-assisted VR (CAVR) in five, Tai Chi as VR (TCVR) in three, canal repositioning manoeuvres (CRM) in one and manual therapy (MT) in one study. Mixed effects were found regarding body structure/function and activities/participation. Quality of life and/or falls were assessed, with no differences between groups. VR is with moderate quality of evidence superior to usual care to improve balance, mobility and symptoms. CONCLUSION: To treat older individuals with VDB, VR in any variation and in addition to CRMs seems to be effective. High-quality randomized trials need to be conducted to inform clinical decision making. TRIAL REGISTRATION: PROSPERO 2017 CRD42017080291 .

Nutrient exchange in arbuscular mycorrhizal symbiosis from a thermodynamic point of view.

To obtain insights into the dynamics of nutrient exchange in arbuscular mycorrhizal (AM) symbiosis, we modelled mathematically the two-membrane system at the plant-fungus interface and simulated its dynamics. In computational cell biology experiments, the full range of nutrient transport pathways was tested for their ability to exchange phosphorus (P)/carbon (C)/nitrogen (N) sources. As a result, we obtained a thermodynamically justified, independent and comprehensive model of the dynamics of the nutrient exchange at the plant-fungus contact zone. The predicted optimal transporter network coincides with the transporter set independently confirmed in wet-laboratory experiments previously, indicating that all essential transporter types have been discovered. The thermodynamic analyses suggest that phosphate is released from the fungus via proton-coupled phosphate transporters rather than anion channels. Optimal transport pathways, such as cation channels or proton-coupled symporters, shuttle nutrients together with a positive charge across the membranes. Only in exceptional cases does electroneutral transport via diffusion facilitators appear to be plausible. The thermodynamic models presented here can be generalized and adapted to other forms of mycorrhiza and open the door for future studies combining wet-laboratory experiments with computational simulations to obtain a deeper understanding of the investigated phenomena.

Functional electrical stimulation-assisted active cycling--therapeutic effects in patients with hemiparesis from 7 days to 6 months after stroke: a randomized controlled pilot study.

OBJECTIVE: To determine whether functional electrical stimulation (FES)-assisted active cycling is more effective than active cycling without FES concerning walking and balance. Specifically, walking ability was classified as to the amount of personal assistance needed to be able to walk and balance was evaluated for static and dynamic balance tasks. DESIGN: Monocentric, randomized, single-blinded, controlled trial. SETTING: Neurologic rehabilitation hospital. PARTICIPANTS: Patients with severe hemiparesis due to stroke (N=40). INTERVENTIONS: Twenty minutes of active leg cycling with or without FES applied to the paretic vastus medialis and rectus femoris of quadriceps and to the biceps femoris and semitendinosus muscles, 3 times/wk for 4 weeks. MAIN OUTCOME MEASURES: Functional ambulation classification (FAC) and performance-oriented mobility assessment (POMA) were the primary outcome measures. The leg subscale of the motricity index (MI) and the modified Ashworth scale were the secondary outcome measures. Evaluation was done before and after the intervention period and after an additional 2 weeks. RESULTS: After the intervention, the FAC, POMA, and the MI (P<.016) for both intervention groups improved significantly. The FAC of the control group increased by a median of 1 category and that of the FES group by 2 categories. The median change in POMA was 2 and 4 points for the control group and the FES group, respectively. The Mann-Whitney U test between-group comparisons revealed that these gains were significantly better in the FES group for both the FAC (U=90; z=-2.58; P=.013; r=-.42) and the POMA (U=60; z=-3.43; P<.0004; r=-.56). Because of missing data and slightly decreased effect sizes during the follow-up phase (FAC, r=-.33; POMA, r=-.41), differences did not reach statistically significant P values. The MI leg subscale showed significant improvements in both groups. However, there were no significant differences between the groups at any time. No changes were observed on the modified Ashworth scale. CONCLUSIONS: FES-assisted active cycling seems to be a promising intervention during rehabilitation in patients with stroke.

Nicotianamine functions in the Phloem-based transport of iron to sink organs, in pollen development and pollen tube growth in Arabidopsis.

The metal chelator nicotianamine promotes the bioavailability of Fe and reduces cellular Fe toxicity. For breeding Fe-efficient crops, we need to explore the fundamental impact of nicotianamine on plant development and physiology. The quadruple nas4x-2 mutant of Arabidopsis thaliana cannot synthesize any nicotianamine, shows strong leaf chlorosis, and is sterile. To date, these phenotypes have not been fully explained. Here, we show that sink organs of this mutant were Fe deficient, while aged leaves were Fe sufficient. Upper organs were also Zn deficient. We demonstrate that transport of Fe to aged leaves relied on citrate, which partially complemented the loss of nicotianamine. In the absence of nicotianamine, Fe accumulated in the phloem. Our results show that rather than enabling the long-distance movement of Fe in the phloem (as is the case for Zn), nicotianamine facilitates the transport of Fe from the phloem to sink organs. We delimit nicotianamine function in plant reproductive biology and demonstrate that nicotianamine acts in pollen development in anthers and pollen tube passage in the carpels. Since Fe and Zn both enhance pollen germination, a lack of either metal may contribute to the reproductive defect. Our study sheds light on the physiological functions of nicotianamine.