A Non-Controlled Study of a Multi-Factorial Exercise and Nutritional Intervention to Improve Functional Performance and Prevent Frailty Progression in Community-Dwelling Pre-Frail Older Adults.

Background: Preventing frailty is important to avoid adverse health outcomes. Intervention studies have largely focused on frail elderly, although the intermediate pre-frail state may be more amenable to improvement. Objectives: This study aims to assess how physical performance may change among pre-frail elderly enrolled in a pragmatic non-controlled exercise and nutritional intervention programme. Methods: This is a non-controlled study involving a 4-month exercise and nutritional intervention for community dwelling pre-frail older adults. Pre-frailty was defined as the presence of 1 or 2 positive responses on the FRAIL questionnaire, or evidence of weak grip strength (<26kg for males; <18kg for females) or slow gait speed (<0.8m/s) amongst participants who were asymptomatic on FRAIL. Physical performance in flexibility, grip and lower limb strength, endurance, balance, and Short Physical Performance Battery were measured at 3 time-points: baseline, 3-month from recruitment (without intervention), and immediate post-intervention. Repeated measures mixed model analysis was performed to compare physical performance measures across the 3 time-points. Results: 94 pre-frail participants were eligible for intervention, of whom 59 (mean age = 70.9±7.2 years) were ready for the post-intervention review. 21 (35.6%) transitioned to robust phenotype while 32 (54.2%) remained as pre-frail. Significant improvement post-intervention was observed in lower limb strength and power, evident on reduction in time taken for 5 sit-to-stand repetitions (0.46±0.20s, p=0.03). There was no significant change to the other physical performance measures examined. Conclusion: We observed reversibility of pre-frailty, and the benefit of multi-component intervention in improving physical performance of pre-frail older adults. The findings in this non-controlled study will need to be corroborated with future controlled trials.

Characterisation and in vitro antimicrobial potential of liposome encapsulated silver ions against Candida albicans.

Liposomes are biocompatible, biodegradable, controlled delivery systems with the ability to encapsulate both lipophilic and hydrophilic compounds, including metal ions. Liposome encapsulated Ag(+) (lipo-Ag(+)), prepared by reverse-phase evaporation, was used as a controlled delivery system against Candida albicans. Characterisation of the lipo-Ag(+) indicated that the multilamellar vesicles with diameters ranging between ≈ 0.5 and 5.0 µm showed potential as a controlled delivery system to consistently deliver Ag(+) to C. albicans. Results from inductively coupled plasma (ICP) analysis showed higher association of cell bound Ag(+) at 15 mins post exposure when compared to unencapsulated Ag(+). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate detrimental effects of Ag(+) on C. albicans cell structure. These effects along with the ICP results also correlate with previously reported time kill experiment observations.

Antimicrobial efficacy of liposome-encapsulated silver ions and tea tree oil against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans.

UNLABELLED: The activity of alternative antimicrobial agents such as tea tree oil (TTO) and silver ions (Ag(+) ) with multiple target sites impedes the development of antibacterial resistance and might be useful in improving the current treatment strategies for various chronic wound infections. In this study, liposome-encapsulated TTO, Ag(+) and TTO plus Ag(+) were added to suspension cultures of Pseudomonas aeruginosa (Ps. aeruginosa), Staphylococcus aureus (Staph. aureus) and Candida albicans (C. albicans). Treatment of these cultures using the agents in combination at subminimal lethal concentrations resulted in an enhanced loss of viability compared to treatment with individual agents. The effective concentration, elimination time (to the limit of detection, LOD) and fractional lethal concentration index (FLCI) of liposomal agents in combination were as follows: Candida albicans: 0·05% v/v TTO:PVA30-70 kDa : 8·9 × 10(-5) % w/v Ag(+) :PVA30-70 kDa : 2·0 h, FLCI = 0·73 (indifferent), Staphylococcus aureus: 0·05% v/v TTO:PVA30-70 kDa : 6·0 × 10(-4) % w/v Ag(+) :PVA30-70 kDa : 1·5 h, FLCI = 0·38 (synergistic), Pseudomonas aeruginosa: 0·25% v/v TTO:PVA30-70 kDa : 3·2 × 10(-4) % w/v Ag(+) :PVA30-70 kDa : 30 min, FLCI = 0·33 (synergistic). These results show the potential for improving antimicrobial efficacy by delivering lower effective concentrations of alternative agents, via controlled release systems. NB All values denoted as %w/vAg(+) refer to the concentration of silver ions. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, we have shown that encapsulating silver (as the ion Ag(+) ) and tea tree oil (singly and in combination) in a controlled release liposomal carrier system can improve their antimicrobial efficacy as well as reduce the effective concentration required. These findings may impact on the problems of agent toxicity caused by the need for high effective doses or microbial resistance where long term application is required.

Antimicrobial efficacy of silver ions in combination with tea tree oil against Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans.

Tea tree oil (TTO) and silver ions (Ag(+)), either alone or in combination with other antimicrobial compounds, have been used in the treatment of topical infections. However, there appears to be little data on the efficacy of TTO combined with silver in the absence of any other agents. TTO and Ag(+) were added, alone and in combination, to suspension cultures of Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Treatment of these cultures with TTO and Ag(+) at sub-minimal lethal concentrations resulted in an enhanced loss of viability compared with treatment with individual agents. The order of sensitivity to the combined agents was P. aeruginosa>S. aureus>C. albicans. The fractional lethal concentration index (FLCI) showed that these combinations of TTO and Ag(+) exerted a synergistic effect against P. aeruginosa (FLCI=0.263) and an indifferent effect against S. aureus and C. albicans (FLCI=0.663 and 1.197, respectively). The results indicate that combining these antimicrobial agents may be useful in decreasing the concentration of antimicrobial agents required to achieve an effective reduction in opportunistic pathogenic microorganisms that typically infect wounds.